# P-47N Thunderbolt vs. F4U-4 Corsair - Which was superior?



## DAVIDICUS (Feb 23, 2005)

I'm curious which of these were better in the air to air role and why.


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## evangilder (Feb 24, 2005)

I'd have to go with the Corsair in air to air engagements on this one. They were both capable air to air fighters, but the Jug was bigger and heavier. The Corsair was designed using the biggest possible engine in the smallest possible airframe. 

The original specification on the Jug, interestingly, called for a small, lightweight fighter! The November 2004 edition of _Air Classics_ has a great article on the Jug.


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## DAVIDICUS (Feb 24, 2005)

The P-47 had the top speed, roll rate, dive speed, armament and protective armor advantages. The P-47 had a high altitude advantage in general performance. 

The F4-U had the manueverability and the climb rate advantage. The F4-U had a low and medium altitude advantage in general performance.

Any disagreement on these attributes?


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## evangilder (Feb 24, 2005)

They were both excellent aircraft. In a pure air to air role, I would think the Corsair would have the edge.


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## Anonymous (Feb 24, 2005)

They were designed for different things. The P-47N was a long range escort plane, the F4U-4 was a patrol/interceptor. The P-47N probably had the advantage above 30,000 feet, the F4U-4 below 30,000 feet. The P-47N had more firepower, the F4U-4 was a little tougher.

Very hard call.

=S=

Lunatic


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## evangilder (Feb 24, 2005)

They were both excellent ground support aircraft as well.


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## R Leonard (Feb 24, 2005)

. . . but you could land a Corsair on a carrier.


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## Anonymous (Feb 25, 2005)

R Leonard said:


> . . . but you could land a Corsair on a carrier.



Sure, but the P-47N had 1000 mile greater range. Kinda fits since the P-47N was a USAAF plane, where the F4U-4 was a USN plane. They were designed for different roles.

=S=

Lunatic


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## Soren (Feb 25, 2005)

In a Dogfight, it would defidently be the Corsair ! 

It could climb faster and it was more maneuverable, plus against the P-47 the F4U Corsair had the rare advantage of being able to out-turn the P-47 

The best thing the P-47 could hope fore against a F4U Corsair, would be a head on attack or, that there was enough altitude to let it dive away from harms way. (Almost nothing could follow a P-47 in a dive !)


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## evangilder (Feb 25, 2005)

R Leonard said:


> . . . but you could land a Corsair on a carrier.



That is true, but a majority of Corsair missions were flown from land bases. When it finally was able to land on the carrier, it was still a difficult task due to that long nose.


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## the lancaster kicks ass (Feb 25, 2005)

i honestly don't know who would win but i'd kinda want the P-47 to win, a very good thread here, shud be some good disscussion...........


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## cheddar cheese (Feb 25, 2005)

I know id rather be in a P-47N... 8)


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## Anonymous (Feb 25, 2005)

Soren said:


> In a Dogfight, it would defidently be the Corsair !
> 
> It could climb faster and it was more maneuverable, plus against the P-47 the F4U Corsair had the rare advantage of being able to out-turn the P-47
> 
> The best thing the P-47 could hope fore against a F4U Corsair, would be a head on attack or, that there was enough altitude to let it dive away from harms way. (Almost nothing could follow a P-47 in a dive !)



Umm... the P-47 was fast into the dive, but a number of planes could dive faster. The Corsair and the P-47 were about equal in initial dive performance (both are very heavy planes) and the Corsair was actually faster (550 mph) under a high degree of pilot control.

In general I'd agree, the F4U-4 probably would have the advantage, but it'd be slight. And the P-47N had TWICE the firepower of the F4U-4, which is a huge factor. Near the end of WWII P-47N's chewed up Franks flown by two of Japan's few remaining ace squadrons, over Korea. One relatively rookie pilot, Oscar F. Perdomo, scored 5 kills that day, becomming the last "Ace in a day" in history.

http://www.elknet.pl/acestory/perdomo/perdomo.htm

=S=

Lunatic

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## DAVIDICUS (Feb 25, 2005)

RG_Lunatic,

What is your source regarding your statement, _"Umm... the P-47 was fast into the dive, but a number of planes could dive faster. The Corsair and the P-47 were about equal in initial dive performance (both are very heavy planes) and the Corsair was actually faster (550 mph) under a high degree of pilot control."_ 

In addition, what is your source for your statement, _"And the P-47N had TWICE the firepower of the F4U-4, which is a huge factor."_

I am certain the latter of your above statements is incorrect and interested to find out if my understanding concerning the former is incorrect.


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## Anonymous (Feb 26, 2005)

DAVIDICUS said:


> RG_Lunatic,
> 
> What is your source regarding your statement, _"Umm... the P-47 was fast into the dive, but a number of planes could dive faster. The Corsair and the P-47 were about equal in initial dive performance (both are very heavy planes) and the Corsair was actually faster (550 mph) under a high degree of pilot control."_
> 
> ...



The P-47 was fast in its initial dive acceleration because it was heavy and had a large engine. But its critical mach level is lower than a number of other planes, and compression limited its maximum dive speed. The Corsair was able to dive at speeds up to 550 mph IAS, which is faster than the max IAS of the P-47.

The P-47N got the .50 M3, which fired at 1200 rpm. That means the ROF was the equivalent of 12 x .50 M2's, double the 6 x M2's on the Corsair. Somewhere I have records of the M3's being delivered to Iwo Shima and one other base, both of which were P-47N bases. Also, pilot comments can be found refering to the faster rate of fire on the P-47N guns.

=S=

Lunatic

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## DAVIDICUS (Feb 26, 2005)

RG_Lunatic:

My understanding was that the M2 was the standard gun used on U.S. aircraft throughout the war. (There certainly was no need to engineer and introduce a fifty with a higher rate of fire. Six fifties were considered more than adequate against other fighters [especially Japanese fighters] and most of the "N" models had eight! Also, as the cyclic rate increases, so do the jams.) 

I'd like to read anything you know of that states differently. I have heard that the rate of fire of the M2 would increase as the belt got used up as the gun would be dragging a lighter ammunition belt although, frankly, I'm not sure about that claim. 

As to the dive claim, please name some of these "number of planes" that could exceed the speed of a P-47 in a dive. I have never read or heard of these planes and everything I have read and heard indicates that the P-47 was faster in a dive than the F4-U, probably due to drag from the different wing loadings. The F4-U's wing loading made is better able to haul heavy loads and require less airstrip to get airborn. Perhaps you've heard of the joke about P-47's - Q: How mush airstrip does a P-47 need to take off? A: All of it!

Perhaps you have some date you can share concerning various "critical mach levels" of different aircraft.

One more unrelated question if you would be so kind as to indulge me. How exactly are the "confirmed kills" and "unconfirmed kills" calculated when you post?

Thanks.


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## Anonymous (Feb 26, 2005)

DAVIDICUS said:


> RG_Lunatic:
> 
> My understanding was that the M2 was the standard gun used on U.S. aircraft throughout the war. (There certainly was no need to engineer and introduce a fifty with a higher rate of fire. Six fifties were considered more than adequate against other fighters [especially Japanese fighters] and most of the "N" models had eight! Also, as the cyclic rate increases, so do the jams.)



The M2 was the standard gun. The M3 was introduced very late in WWII. Apparently it was only used for the top front turret on a few B-29's and the P-47N. Years ago I tracked the shipments of the approximately 18,000 M3's deployed during WWII to 3 bases, one of which was Iwo Shima, which only fielded P-47N's in any significance. The P-47N was ideal for the M3 because of its huge ammo supply of 500 rpg, and I believe it had a power assist belt feed. I believe the F-86 also sported the M3 in Korea, but aside from that it has only been used on helicopters. The jam rate probably did increase, but given that the M2 had a Jam rate of only about 1/3rd the rate of the Hispano or MG151/20, how is this relevant? Also, steralite lined barrels and other improvements to the M3 design would mitigate the increase in jam rate. And evidence from the use of the "nickle trick" is that it did not significantly increase jam rates, but that it did tend to wreck guns by cracking the reciever after a dozen or so sorties - but usually these guns were still working when the cracks were found by the armorers!



DAVIDICUS said:


> I'd like to read anything you know of that states differently. I have heard that the rate of fire of the M2 would increase as the belt got used up as the gun would be dragging a lighter ammunition belt although, frankly, I'm not sure about that claim.



I'll have to search for the info. It's been 4 or 5 years, two moves, three machine and two or three OS updates since I dug out the records. It's in some military accounting records somewhere (the tracking of the M3's) which should be easy to find if the urls are still good, but which will be hard if I have to locate them in old offline content under an old OS installation (which sucks because there is no way to view it short of firing up the old installation).

BTW: another thing that effects RoF is gun age. Older guns tend to fire faster as the springs become worn.



DAVIDICUS said:


> As to the dive claim, please name some of these "number of planes" that could exceed the speed of a P-47 in a dive. I have never read or heard of these planes and everything I have read and heard indicates that the P-47 was faster in a dive than the F4-U, probably due to drag from the different wing loadings. The F4-U's wing loading made is better able to haul heavy loads and require less airstrip to get airborn. Perhaps you've heard of the joke about P-47's - Q: How mush airstrip does a P-47 need to take off? A: All of it!
> 
> Perhaps you have some date you can share concerning various "critical mach levels" of different aircraft.



Sure. Spitfire XIV = 0.89, Tempest = 0.83, P-51B = 0.84, P-38 = 0.65, P-47C = 0.69

Note: "limiting mach" is usually figured at about 0.02 below crtical mach, which is where the really bad behavior hits hard.

Of course, the P-47N would have had a better critical mach figure than the C model. The experimental J model had a critical mach of 0.83.

I have not been able to find anything more on the F4U critical mach figure than that it was "comparable to the P-51", other than that the prototype in 1941 got a figure of 0.73 in the wind tunnel - which probably would translate to about 0.78 true.




DAVIDICUS said:


> One more unrelated question if you would be so kind as to indulge me. How exactly are the "confirmed kills" and "unconfirmed kills" calculated when you post?
> 
> Thanks.



LOL - I have no idea. You will have to ask a board Admin.

=S=

Lunatic


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## cheddar cheese (Feb 26, 2005)

I dont know how theyre calculated, its kinda random  As a general rule, the more you put in a post, the more you get.

(The reason mine are so low is cos im on here so much and it limits you to certain amounts a day)


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## DAVIDICUS (Feb 26, 2005)

RG_Lunatic:

Are you saying that the Spitfire XIV, Tempest, P-51B, and P-38 could exceed the P-47 in dive speed? I don't think so but at present can offer nothing more in support than what appears below. 

Chuck Hawks wrote an article "The Best Fighter Planes of World War II." In it, he favored the P-51. He received a letter from Lt. Rip Collins who piloted both P-51's and P-47's in the 35th Fighter Group in the Pacific. Lt. Collins took him to task citing several reasons why the P-47 was a better fighter than the P-51. See number 4 below. If the Corsair's dive speed was "comparable to the P-51" as you mentioned, then Lt. Collins claim would indicate that the P-47 was superior to the Corsair in a dive.


1. The Republic Thunderbolt had a radial engine that could take hits and keep on running. I know of an actual case where a Jug brought a pilot back from Borneo after 8 hours in the air. The pilot landed with the master cylinder and three other cylinders blown out of commission. But the Jug kept chugging along, running well enough to bring its pilot back safely to his base at Morotai. I was there.

2. The Jug's radial engine was air cooled, instead of liquid cooled with a radiator system, like the Mustang's V-12. This is significant because one small caliber hit on an aluminum cooling line in a Mustang would let the coolant leak out, and when the coolant was gone, the engine seized, and the show was over. I took a small caliber hit in a coolant tube over Formosa (Taiwan). When I landed back at base, my crew chief said, "Lieutenant, did you know you got hit?" I replied, "No." He continued, "You took a small caliber shell in the coolant tube on the right side of the engine. I'd give you between 10 and 15 minutes flying time remaining." I had just flown from Formosa, over nothing but the Pacific Ocean, to our fighter strip on Okinawa.

3. The P-47 could fly higher than the P-51. With its huge turbocharger, it could climb to over 40,000 feet. You could just look down at your enemy in a stall and smile.

4. The Jug could out dive the Mustang. As a matter of fact, it could out dive any enemy fighter, and at 7.5 tons loaded, it dove fast! I have personally been in a dive at what we called the "state of compressibility," at nearly 700 mph indicated air speed. I was scared to death, but with a tiny bit of throttle, I pulled it out at about 2,000-foot altitude, literally screaming through the sky.

5. The Thunderbolt had eight .50's. The Mustang had six. That's 33 1/3% more firepower. This made a major difference.

6. The later model Thunderbolt's could carry and deliver 2,500 pounds of bombs. (One 1,000-lb. bomb on each wing, and one 500 lb. bomb under the belly.) This was a maximum load and you had to use water injection to get airborne. But it would do this with sufficient runway. I have done this myself.

In addition to being a first class fighter, it was also a superb fighter-bomber and ground level strafer. Jugs practically wiped out the German and Italian railroads. I have strafed Japanese trains, troops, ships, gunboats, warships, airfields, ammo dumps, hangers, antiaircraft installations, you name it. I felt secure in my P-47.

7. The P-47 was larger and much stronger, in case of a crash landing. The Jug was built like a machined tool. Mustangs had a lot of sheet metal stamped out parts, and were more lightweight in construction. One example was the throttle arm. You can see the difference. What does all this mean? The safety of the fighter pilot.

8. The Thunderbolt had no "scoop" under the bottom. You can imagine what happens during a crash landing if your wheels would not come down (due to damage or mechanical trouble). On landing, it could make the P-51 nose over in the dirt as the scoop drags into the earth. In water (and I flew over the Pacific Ocean most of my 92 combat missions), it could cause trouble in a crash landing because the air scoop would be the first part of the aircraft to hit the water. Instead of a smooth belly landing, anything might happen.

9. The Thunderbolt had a much larger, roomier cockpit. You were comfortable in the big Jug cockpit. In my Mustang, my shoulders almost scraped the sides on the right and left. I was cramped in with all my "gear." I could not move around like I could in the P-47. I found the ability to move a little bit very desirable, especially on seven and eight hour missions.

10. The Mustang went from 1,150-horse power Allison engines to the Packard built Rolls-Royce Merlin engine that had 1,590 hp. The Thunderbolt started out with a 2,000 hp Pratt Whitney engine, and ended up with 2,800 war emergency hp with water injection. That's close to twice the power.

11. The Jug had a very wide landing gear. This made it easy to land just about anywhere, with no tendency to ground loop. Many times we had to land on rice paddies and irregular ground. When you set the Thunderbolt down, it was down. In the Far East, England, Africa, and Italy, this helped you get down and walk away from it. To me, that was very important for the safety of the pilot.

12. The Jug's record against all opposing aircraft is remarkable. The ratio of kills to losses was unmistakably a winner. Thunderbolt pilots destroyed a total of 11,874 enemy aircraft, over 9,000 trains, and 160,000 vehicles.


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## cheddar cheese (Feb 26, 2005)

The Jug certainly was tough, someone posted on here a while back that they had read of a P-47 literally flying through trees (on purpose!) and surviving


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## Anonymous (Feb 26, 2005)

DAVIDICUS said:


> RG_Lunatic:
> 
> Are you saying that the Spitfire XIV, Tempest, P-51B, and P-38 could exceed the P-47 in dive speed? I don't think so but at present can offer nothing more in support than what appears below.



The P-38 critical mach number was lower than that of the P-47, to it's max dive speed would be even lower.

It is important to understand that initial dive acceleration is a huge part of the "dive" performance. This is where the P-47 (and almost all US planes by virtue of their weight) excelled. At the start of the dive a P-47 could quickly pull thousands of feet away of a pursuer. After that, planes with higher critical mach figures would start to slowly catch up.

Also, critical mach figures usually indicate where the plane stops being responsive to controls, and often reflect wing and tail surface mach levels. At this point portions of the airflow over the plane such as the cowl and canopy might already be exceeding mach airflow, causing undesirable flying characteristics. The pursued plane would be less concerned with this than the pursuer, as he does not need to shoot.

Another important issue is terminal dive speed. Both the P-38 and the P-47 (and espeically the Me262) had serious terminal dive speed issues (where a dive could not be recovered and meant an inevitable crash), which were eventually "solved" through the use of dive recovery flaps. Dive recovery flaps had to be deployed at the beginning of a dive, once high speed was attained the hydrolics could not deploy them. These flaps had to reduce the critical mach figure for the planes and also acted as air brakes slowing dive acceleration.

Anyway, both the P-47 and the F4U were large planes with about the same relative power, so both would have had similar initial dive acceleration. The P-47N had a psuedo-laminar flow wing, so perhaps it's critical mach was equal to or higher than that of the F4U-4. Also, the F4U-4 had to be very careful above about 535 mph IAS or the fabric on the wings could be ripped off.

Attached is an interesting document concerning the behaivor of the Spitfire IX at high fractions of mach.

The 700 mph figure quoted is rubbish. Down low the air is just too thick for such speeds from a P-47 (and have the pilot survive), up high that exceeds mach 1. I suspect either the pilot was exagerating or the airspeed indicator was inaccurate at such high speeds (very likely). The maxium reading on the air speed indicator of the P-47 is 700 mph. Any dive steep enough to exceed much over 550 mph in a P-47 was probably terminal. A P-47 at 250 mph at 25,000 feet could not execute a normal power split-S without eating dirt!

=S=

Lunatic


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## Anonymous (Feb 26, 2005)

cheddar cheese said:


> The Jug certainly was tough, someone posted on here a while back that they had read of a P-47 literally flying through trees (on purpose!) and surviving



The USAAF and USN conducted post war tests and determined the F4U was the tougher plane. Its wing spar is much stronger (to support carrier operations) and the P-47's turbo-supercharger and fuel tank layout made it more vulnerable to enemy fire.

=S=

Lunatic


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## the lancaster kicks ass (Feb 26, 2005)

altough that's not to say that the P-47 couldn't take damage...........

an CC can you find this post as there were several mentions of P-47's flying through the trees as in below tree top level but no single engined plane could literally fly into a tree and survive.......


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## cheddar cheese (Feb 26, 2005)

No I cant find it...it was months ago and ive no idea where I read it...


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## the lancaster kicks ass (Feb 26, 2005)

well like i said if i'm thinking of the same one as you they were flying below tree top height, think about it, not even the P-47 or corsair could survive a crash with a tree............


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## cheddar cheese (Feb 26, 2005)

You do know I mean just the foliage, not the trunk...


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## Anonymous (Feb 26, 2005)

the lancaster kicks ass said:


> altough that's not to say that the P-47 couldn't take damage...........
> 
> an CC can you find this post as there were several mentions of P-47's flying through the trees as in below tree top level but no single engined plane could literally fly into a tree and survive.......



There were many cases of P-47's flying into ground objects and surviving. The most famous is one that flew into a radio tower, tore of several feet of one wing, and still made it home.

Also there are many accounts of P-47's, and espeically Corsairs which clipped the tops of trees with their props and survived.

=S=

Lunatic


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## DAVIDICUS (Feb 26, 2005)

RG_Lunatic:

You still haven't convinced me that, as you stated, "The Corsair was able to dive at speeds up to 550 mph IAS, which is faster than the max IAS of the P-47." 

You now state, "The P-47N had a psuedo-laminar flow wing, so perhaps it's critical mach was equal to or higher than that of the F4U-4. Also, the F4U-4 had to be very careful above about 535 mph IAS or the fabric on the wings could be ripped off." 

So it sounds like the P-47 would have an initial dive acceleration advantage due to weight and a likely terminal advantage due to a higher critical mach as well.

On another note, I don't see why Collins claim of "nearly 700 mph indicated airspeed" couldn't be true. He did not say that he was diving at an actual airspeed of 700 mph. You, of course, know what IAS means and I understand that the IAS device was often inaccurate at high speeds. In addition, I would not be surprised if there was a little exaggeration there. He did, however, clearly say that the P-47 was superior to the P-51 in a dive (and he flew both) and you indicated that the Corsair had a critical mach comparable to the P-51.

This is rather nitpicky, I know. I would agree with you that below 30K, the Corsair would have the edge and that that edge would be progressively greater as altitude decreased. Over 30K altitude though, I think the P-47 would wax the corsair.


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## Anonymous (Feb 26, 2005)

DAVIDICUS said:


> RG_Lunatic:
> 
> You still haven't convinced me that, as you stated, "The Corsair was able to dive at speeds up to 550 mph IAS, which is faster than the max IAS of the P-47."
> 
> ...



Initial dive acceleration would be pretty close. 535 IAS was about the limit of the P-47 as well. If the F4U's fabric had been tightened before the sortie, it could dive faster - the pilot had to pay attention for signs it was rippling.



DAVIDICUS said:


> On another note, I don't see why Collins claim of "nearly 700 mph indicated airspeed" couldn't be true. He did not say that he was diving at an actual airspeed of 700 mph. You, of course, know what IAS means and I understand that the IAS device was often inaccurate at high speeds. In addition, I would not be surprised if there was a little exaggeration there. He did, however, clearly say that the P-47 was superior to the P-51 in a dive (and he flew both) and you indicated that the Corsair had a critical mach comparable to the P-51.



I agree perhaps Collins' claim of the gauge being pegged could be true - if it was poorly calibrated for high speeds or was defective.

The P-47 would pull away from the P-51 quickly at the start of a dive, but then the P-51 would overtake it. This is a known fact from multiple flight tests. The Corsair would do better at the start of the dive than the P-51 because of its weight.



DAVIDICUS said:


> This is rather nitpicky, I know. I would agree with you that below 30K, the Corsair would have the edge and that that edge would be progressively greater as altitude decreased. Over 30K altitude though, I think the P-47 would wax the corsair.



Well, I agree with that. The Turbo-superhcarger on the N was still working well at 35K, the Corsair's was finished by about 30K.

=S=

Lunatic


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## Anonymous (Mar 2, 2005)

DAVIDICUS said:


> RG_Lunatic:
> 
> My understanding was that the M2 was the standard gun used on U.S. aircraft throughout the war. ...



Just an additional note. The F8F-1 was armed with 4 x M3 .50 BMG's. This gave it the equivilant firepower of 6 x .50's that were deemed sufficient for air-to-air combat.

=S=

Lunatic


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## DaveB.inVa (Mar 2, 2005)

RG_Lunatic said:


> Also there are many accounts of P-47's, and espeically Corsairs which clipped the tops of trees with their props and survived.



There was a bombardier I knew who flew in B-24's in the Pacific. He talked all the time about flying in the trees with the glazed nose of the B-24D being raked through limbs with the props chopping through everything. He said they did it just about all the time.


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## evangilder (Mar 2, 2005)

From the book The Pratt Whitney Aircraft Story:

The P-47 was a rugged airplane, without a doubt. During the Battle of the Bulge in 1944, German Field Marshal von Rundstedt had hidden a munitions dump in the woods of the Ardennes. P-47s were called upon to destroy it, but they couldn't find it because of the thick trees. What did the frustrated pilots do then? They flew through the tops of the trees!

 Pratt Whitney's representative in Europe, Martin Graham, was there not long afterwards. "You could see by the shattered trees and the torn branches where the P-47s had gone through. You'd have to see it to believe it. Those crazy kids couldn't see what was hidden from above, so they went right into the forest to find out. They cut a path right through the top of the woods. They said every plane that went in and chewed out the tunnel came out — flying, too."


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## the lancaster kicks ass (Mar 2, 2005)

bloody hell


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## evangilder (Mar 2, 2005)

Yes, that is pretty amazing! It took a serious pair of pods to be the first guy to try that!

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## cheddar cheese (Mar 2, 2005)

I know id read about that somewhere! 8)


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## CharlesBronson (Mar 5, 2005)

Aeronavale F4U low pass.


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## Jank (Apr 18, 2005)

Now this was a bloody Platinum Match.


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## DAVIDICUS (Apr 30, 2005)

Agreed.


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## Jank (May 19, 2005)

How did teh new wing on the N model affect its manuverability?


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## Rafe35 (Jun 29, 2005)

I found interesting in this topic. 

Some Facts about P-47N Thunderbolt and F4U-4 Corsair....

*Speed:* The P-47N Thunderbolt is 21 mph faster than the F4U-4 Corsair and that also 30 mph faster than P-51D Mustang.
Advantage: P-47N Thunderbolt

*Climb:* 
F4U-4 Corsair Rate of climb = 3870 ft/min
P-47N Thunderbolt Rate of climb = Unsure
Advantage: Unsure

*Armament:* F4U-4 Corsair has 6 x .50 Cals machine guns while P-47N equip with 8 x .50 Cals, but the F4U-4B, the version fitted with four 20mm cannon in place of the six 12.7mm machine guns, kept the very same features as the basic model. The F4U-4B Corsair did not see action in WWII, but it was used with success in the Korean War (1950-1953) and Soccer War (Known as 1969 Football War) as well. 
Advantage: P-47N Thunderbolt 

*Survivability:* There was no other single engine fighter flown during the war that could absorb greater battle damage than the F4U Corsair and still get home. Even the USAAF admitted that the F4U was a more rugged airframe than the tank-like P-47 Thunderbolt. That is a remarkable admission. The big Pratt Whitney radial engine would continue to run and make power despite have one or more cylinders shot off (Both fighter used Pratt Whitney).
Advantage: Tie 

If anyone disagree about my facts between P-47N Thunderbolt and F4U-4 Corsair, please discuss it here because some of them might be false since I have been looking them up quite for long time.


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## FLYBOYJ (Jun 29, 2005)

Rafe35 said:


> *Survivability:* There was no other single engine fighter flown during the war that could absorb greater battle damage than the F4U Corsair and still get home. Even the USAAF admitted that the F4U was a more rugged airframe than the tank-like P-47 Thunderbolt. That is a remarkable admission. The big Pratt Whitney radial engine would continue to run and make power despite have one or more cylinders shot off (Both fighter used Pratt Whitney).
> Advantage: Tie



I've been up close to both of em, I could tell you the Corsair in some places is a lot more beefer than the -47. I think this robustness came from not only the desire to have a strong fighter, but also from it being designed as a carrier borne aircraft.


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## DAVIDICUS (Jun 29, 2005)

What areas?


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## FLYBOYJ (Jun 29, 2005)

DAVIDICUS said:


> What areas?



Underside - close to where the wings folded, the landing gear area and the lower fuselage. The structure around the tail was also a brick sh*t house as well!


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## Rafe35 (Jun 29, 2005)

FLYBOYJ said:


> Rafe35 said:
> 
> 
> > *Survivability:* There was no other single engine fighter flown during the war that could absorb greater battle damage than the F4U Corsair and still get home. Even the USAAF admitted that the F4U was a more rugged airframe than the tank-like P-47 Thunderbolt. That is a remarkable admission. The big Pratt Whitney radial engine would continue to run and make power despite have one or more cylinders shot off (Both fighter used Pratt Whitney).
> ...


I know the F4U-4 Corsair have bullet-proof "Malcom Hood" windshield that supposed to protect the pilot while engaged against fighters and Anti-Aircraft guns. I know the Japanese could not shoot down the F4U-4 Corsair before War ended because it was faster and much better than past Corsair variants, but still unsure about P-47N Thunderbolt (I know they had few kills like F4U-4 but were they shot down by Japanese or AA guns?).


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## DAVIDICUS (Jun 29, 2005)

Unlike the Thunderbolt, the Corsair was designed to be able to survive controlled crash landings onto carrier decks. Such hard landings placed very high stress on the landing gear assembly and the parts of the frame through which the stress of those landings was initially absorbed and dispersed throughout the aircraft. 

As far as whether the Thunderbolt or Corsair, while airborne, could absorb more damage from machine gun / cannon fire and bring its pilot home, I don't know.

I wish I knew where that statement of the admission from the USAAF that the Corsair was more rugged came from so that it could be seen in context.

I understand that the aluminum skin on the Thunderbolt was thicker than the Corsair's. There were no fabric control surfaces either. The semi-monocoque and multi-cellular structure of the P-47's fusalege and wings certainly looks more rugged in drawings than the Corsair too.

Any thoughts on ruggedness in flight as opposed to with respect to crash landing on a carrier deck?


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## FLYBOYJ (Jun 29, 2005)

DAVIDICUS said:


> I understand that the aluminum skin on the Thunderbolt was thicker than the Corsair's. There were no fabric control surfaces either. The semi-monocoque and multi-cellular structure of the P-47's fusalege and wings certainly looks more rugged in drawings than the Corsair too.
> 
> Any thoughts on ruggedness in flight as opposed to with respect to crash landing on a carrier deck?



I think in some cases they might be about the same.

I think the ruggedness of the Corsair was based around it being operated on a carrier


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## wmaxt (Jun 29, 2005)

FLYBOYJ said:


> DAVIDICUS said:
> 
> 
> > I think the ruggedness of the Corsair was based around it being operated on a carrier
> ...


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## FLYBOYJ (Jun 29, 2005)

wmaxt said:


> FLYBOYJ said:
> 
> 
> > DAVIDICUS said:
> ...


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## Sal Monella (Nov 14, 2005)

I believe the skin on the Thunderbolt was thicker than on the Corsair. Didn't the Corsair have some fabric covered surfaces?


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## FLYBOYJ (Nov 14, 2005)

It did, especially the earlier ones, but I seen both up close and the Corsair had some of it's structure just as beefy as the -47


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## Sal Monella (Nov 14, 2005)

So the consensus seems to be that over 30,000ft, the P-47 would wax the Corsair due to the turbo-supercharger being able to pump out 100% of it's 2,800hp even at 32,000ft.

What was the horsepower of the Corsair's engine at that altitude?


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## Jank (Nov 14, 2005)

The F4U4 that saw service didn't have as powerful an engine as the "C" series 2,800hp powerplant that was installed into the P-47N. It also didn't have the supercharger that the P-47 had. 

A later development of the F4U4 had a more powerful engine that developed 2,760hp but these came too late to see service and still couldn't generate that hp level at high altitude like the 47.


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## wmaxt (Nov 14, 2005)

Jank said:


> The F4U4 that saw service didn't have as powerful an engine as the "C" series 2,800hp powerplant that was installed into the P-47N. It also didn't have the supercharger that the P-47 had.
> 
> A later development of the F4U4 had a more powerful engine that developed 2,760hp but these came too late to see service and still couldn't generate that hp level at high altitude like the 47.



That is just the difference between superchargers and Turbo-supercharger systems.

wmaxt


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## book1182 (Nov 14, 2005)

F4U all the way. It turned better, and matched the P-47 in almost every aspect. I do like the P-47 though in the ground attack role though.


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## Sal Monella (Nov 14, 2005)

P-47N had superior roll rate, dive, acceleration, speed, armament and range.

Corsair had better climb and turn.

At low and medium altitudes, I think the Corsair was better in the air to air role. Over 30,000ft, I think the Corsair's engine suffered enough to push the P-47N ahead of the Corsair in climb as well. 

The F4U-4 had a WEP 2,450 hp engine that lacked the turbo-supercharger that the 2,800hp P-47N had. The P-47N was still generating 2,800hp at 32,000ft.

Lastly, until the dash 5, the outer top wing panels and the control surfaces of the Corsair were fabric covered. The F4U-5 was the first all metal skinned Corsair.

Real men don't go for fabric covered control surfaces. Fabric is what womens' skirts are made of.


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## syscom3 (Nov 14, 2005)

Sal Monella said:


> Real men don't go for fabric covered control surfaces. Fabric is what womens' skirts are made of.

Reactions: Like Like:
1 | Like List reactions


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## FLYBOYJ (Nov 14, 2005)

Sal Monella said:


> Lastly, until the dash 5, the outer top wing panels and the control surfaces of the Corsair were fabric covered. The F4U-5 was the first all metal skinned Corsair.
> 
> Real men don't go for fabric covered control surfaces. Fabric is what womens' skirts are made of.



Actually the ailerons were made from wood.....

http://www.americanaeroservices.com/images/Projects/F4u/f4uRestoration/F4uWing.jpg


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## JonJGoldberg (Nov 19, 2005)

Great topic… My vote >> Plane Vs plane > P-47, but maybe not the N, but the D-25. This plane's range is a bit less than the F4U-4, but in the air, it was the best '47 variant. Fuel in the wings, and the fuselage extension did not benefit the '47's aerobatic performance; although the increased power, fuselage extension (2”), wing air flow improvements did increase its speed. Modification to the T-bolt to N variant was done purely for range; with as little degradation to performance as possible.

I believe the '47 was at the end of its 'design life cycle', jet aircraft not withstanding. The Corsair, was (a) younger (design), it was not an adaptation, or improvement of an earlier design. From a clean sheet it was purposely designed to be fitted with the P&W R-2800, unlike the P-47, whose forbearers were powered by ‘smaller’ engines, the Corsair was designed to be a carrier aircraft. The limits of prop tech. service aboard carriers forced the gull wing shape ( to it's advantage, as the T-Bolt had a 6" clearance with the four bladed paddles, ones finally fully able to 'transfer' the output probably the best aircraft power plant of the war, the P&W R2800, on take-off/landing). The Corsair had quite an extended development time (maybe the longest, of that period, exceeding even the design life of the Lighting) for a combat fighter aircraft, was in fact superseded (as a carrier fighter) by it's friendly rival the Hellcat which 1st flew a full year after the F4U was ordered into production, which the Corsair never fully replaced in service during WW2. The wing shape of the Corsair is/was its primary advantage, similarly it's primary weakness (it is also the reason I fell in love with WW2 aircraft in the first place). As far as flight characteristics are concerned it's definitely more a weakness than a benefit.

More on topic… 

The strength needed to absorb carrier landings, as evidenced by the thicker sheet metal used in the under-fuselage between the wings of the Corsair is mandated by two minor factors unique of the 'gull shape' wing: 1- The 'inverted gull shape' wing shortened the undercarriage length, increasing both the undercarriage’s strength (good), its transfer of energy to the airframe (bad), as the 'suspension' has less travel therefore less ability to ‘absorb’ landing energies (the Corsair had a rep for bouncing) requiring more of the stressed skin of the Corsair to be strengthened against ‘flex’. 2-The other factor is one of geometry. An angled wing increases its length at a greater rate than it increases its span, therefore although the Corsair and Jug ( had effectively similar landing gear track wing spans{P-47-D}), the frame of the Corsair needed to be ‘reinforced’ over a greater length again requiring more of the stressed skin of the Corsair to be strengthened against ‘flex’. I believe this light might shed some insight upon claims (I here tell that even the ‘Air Force’ guys said…) the Corsair may have been a tougher bird.

Within that section of a Jug, under-fuselage between the wings, suspended by an airframe flight rated to +8Gs, with an operating window of 14Gs (the Corsair was rated to +7.3Gs with an operating window of 12.3Gs) are the T-bolts armored fuel cells, armored supercharging plumbing, space for the wheels, covered by sheet metal whose only service is to provide an aerodynamically clean surface, therefore not requiring the strengthening found on the Corsair in this area. Additionally the P-47’s airframe was not ‘strengthened’ to tolerate carrier landing, or ‘inverted gull shaped wing’ stresses; instead it was ‘strengthened’ to absorb flight stresses. I believe that it was the toughest bird produced in the USA, not as rigid as an Fw190, or Yak-3.

So, although the skin of the ‘Bolt may be thinner in places of similar locations as compared to the Corsair, sometimes the locations are not performing the same tasks.

As for the rest of the performance stuff, may I offer here the suggestion of visiting the Best Fighter of WW2 section to download my WW2 fighter comparison tables, which contain, as it happens, both the P-47N F4U-4. A photo shows the rest of the aircraft listed. Hopefully I’ll be visiting here again soon.


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## Sal Monella (Nov 19, 2005)

Jon, with respect to your assertion that, "Fuel in the wings, and the fuselage extension did not benefit the '47's aerobatic performance; although the increased power, fuselage extension (2”), wing air flow improvements did increase its speed."

Please see http://home.att.net/~historyzone/Seversky-Republic8.html

You will note that the "N" proved superior to the D in every respect. In addition, where did you get your information that the fuselage was lengthened in the "N" model? Pleae provide a source or other evidence.
------------------------------------------------------------
The XP-47N took to the air for the first time on July 22, 1944. Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further. In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt. Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence.


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## Sal Monella (Nov 19, 2005)

Frank Perdomo, who is known for having become an "ace in a day" by shooting down five Japanese aircraft, flew the P-47N out of Le Shima. He said that the P-47N was like a "different aircraft" compared to the "D" model.

Hardly a modification of the D model with as little degradation in performance as possible, it was a very hot ship with phenominal performance more akin to the "M" that the "D". Indeed, the "N" model was at the end of it's design cycle because the limits of propeller driven aircraft performance had been reached. 

However, be advised that the XP-72 and XP-47J were P-47 developments that reached speeds of 490mph and over 500mph respectively so there weas indeed a little room left for perfomance enhancement of the P-47.


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## JonJGoldberg (Nov 20, 2005)

Reply To Sal Monella>>>>

From the book The Illustrated History Of Fighters, by Bill Gunston, Exter books, 1981, page 107, *P-47N Thunderbolt Length: 36' 4"*

Performance of the *P-47N-5-RE *included a maximum speed of 397 mph at 10,000 feet, 448 mph at at 25,000 feet, and 460 mph at 30,000 feet. Initial climb rate was 2770 feet per minute at 5000 feet and 2550 feet per minute at 20,000 feet. Range (clean) was 800 miles at 10,000 feet. Armanent included six or eight 0.50-inch machine guns with 500 rpg and two 1000-lb or three 500-lb bombs or ten 5-inch rockets. Weights were 11,000 pounds empty, 16,300 pounds normal loaded, and 20,700 pounds maximum. Dimension were wingspan 42 feet 7 inches, *length 36 feet 4 inches*, height 14 feet 7 inches, and wing area 322 square feet.

Specifications of the *P-47D-25-RE*: One Pratt and Whitney R-2800-59 Double Wasp eighteen-cylinder air-cooled radial, war emergency power of 2535 hp. Maximum speed was 429 mph at 30,000 feet, 406 mph at 20,000 feet, 375 mph at 10,000 feet, 350 mph at sea level. Initial climb rate was 2780 feet per minute. Climb rate at 30,000 feet was 1575 feet per minute. Service ceiling was 40,000 feet, and range was 950 miles at 10,000 feet. Range with maximum external fuel was 1800 miles at 10,000 feet at 195 mph. Weights were 10,700 pounds empty, 14,600 pounds normal loaded, and 17,500 pounds maximum. Dimensions were wingspan 40 feet 9 3/8 inches, *length 36 feet 1 3/4 inches*, height 14 feet 7 inches, and wing area 300 square feet. 

The above can be referenced @
http://home.att.net/~jbaugher1/p47.html

*SPECIFICATIONS (P-47D)*
Span: 40 ft. 9 in. 
*Length: 36 ft. 2 in.* 
Height: 14 ft. 8 in. 
Weight: 17,500 lbs. max. 
Armament: Six or eight .50 cal. machine guns and either ten rockets or 2,500 lb. of bombs 
Engine: One Pratt Whitney R-2800-59 of 2,430 hp. 
Crew: One 
Cost: $85,000 

PERFORMANCE 
Maximum speed: 433 mph. 
Cruising speed: 350 mph. 
Range: 1,030 miles 
Service Ceiling: 42,000 ft. 

The above information can be found @
http://www.wpafb.af.mil/museum/air_power/ap.htm

The article quote to which you refer provides info on the XP-47N, undergoing 'Factory' testing. The hype of this 'Factory' testing, wouldn't have allowed any other outcome than the one you quoted. You are quite right in pointing out the improvements in roll rate, and overall maneuverability the new wing brought to the Thunderbolt. However, consider the following... "_the war in the Pacific required fighter ranges even greater than did operations over Germany. In pursuit of better long-range performance, in mid-1944 the third YP-47M prototype (42-27387) was fitted with a new "wet" wing of slightly larger span and area. The aircraft was redesignated XP-47N. For the first time in the Thunderbolt series fuel was carried in the wings, a 93 US gallon tank being fitted in each wing. When maximum external tankage was carried, this brought the total fuel load of the XP-47N up to an impressive 1266 US gallons. This fuel load make it possible for a range of 2350 miles to be achieved_. 

_The new wing also incorporated larger ailerons and squared-off wingtips. These innovations enhanced the roll-rate of the Thunderbolt and improved the maneuverability. The dorsal fin behind the bubble canopy was somewhat larger than that on the P-47D. However, the increased fuel load increased the gross weight of the aircraft. In order to cope with the increased gross weight, the undercarriage of the XP-47N had to be strengthened, which increased the weight still further. The maximum weight rose to over 20,000 pounds."_

The above in _italics_can be referenced @
http://home.att.net/~jbaugher1/p47_13.html (for you Sal)

Anyway... The XP-47N did not have the modified undercarriage, and structural enhancements of the P-47N production variants as the N's wet wings replaced the YP-47M's wings, that were attached to a D's loner body,at the savings of about 300 pounds (The difference in empty weights D/N). So I do not believe they could they have flown the XP-47N at anywhere near it's true 'combat' weight, during it's so called mock battles, or range tests; instead the XP-47 was flown at best, at the D's combat weight (but probably more like the M's pre-production 'combat weight'). Remember Sal, the loner YP-M was developed to demonstrate the ability of the -47 as a pure fighter, designed to catch 'buzz bombs'. You remove 3,000lbs from an aircraft (The difference in combat weights D/N), and this weight savings provided the XP-47N with a very serious advantage, do you agree?. Add to that, the power difference well....

The reality of your article is that a mock battle/s between a 'hot roded' D vs a standard D netted in the standard D's loss, as planed. Any advantage the standard D had/s over the standard N, such as turn rate climb, are lost in this 'demonstration'. In my tables all numbers are at 'combat' weight. The only weight were there is even a remote chance at a 'level playing field'.
The one thing we agree, at least for now, on is that the N was indeed quite different than the D. In reality the N indeed defeats the D. In my tables N indeed defeats the D. But we are not talking reality here, as the two never fought (F4U vs P47, or P47vs P47).So I'm taking this posture, D as opposed to N, for the following reasons... @ combat weight, on production versions, the D's superior turning rate climb combined with it's level stall characteristic on my personal dogfighting scale, defeats the D's roll speed advantage.


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## Sal Monella (Nov 20, 2005)

Jon, I think you're looking at a typo as far as the dofference in length. I have never seen any lengthening of the fuselage referenced in any publication. If you can point out a reference to the lengthening of the fuselage that would support this length discrepency, I would concede.

I may have misunderstood your last post so please do not be upset if the following argument appears to mistate the points and argument you have raised.

As far as your assertion that both "D" and "N" models should be compared at "combat weight" because in your words, it would be "The only weight were there is even a remote chance at a 'level playing field', I ask that you consider the following: 

The "D" and "N" models are designed with fundamentally different roles. The "N" is obviously an extreme range escort fighter. As far as comparing "combat weight" of both the "D" and "N" models, I don't think that that is a fair comparison as the fuel load of an "N" model in "combat load" configuration is supposed to carry the aircraft well, well beyond the range of a "D" model in its "combat weight" configuration. Put differently, the combat weight of an "N" model includes an enormous fuel load and weight not borne by the "D" model in the same configuration. 

Now, for a proper apples to apples comparison of both aircraft fulfillng the same role, you would not use a far larger and heavier fuel load in only one aircraft and since it would be impossible to load up the "D" with internal fuel to match the "N", you must do the reverse or reduce the internal fuel load of the "N" to match the "D".

Under this scenario, where both aircraft can be loaded to actually perform in the same role, the performance of the "N" with the wider, squared off wings and "C" series engine far exceeds the performance of the "D" model. The climb rate you have quoted for the "N" for instance would instead be very close to the "M" model which is close to 3,800fpm at 5,000ft.

See the thread entitled Republic Aviation Performance Data - P-47"M" and P-47 "N" on page 4 of this forum.

http://www.ww2aircraft.net/forum/viewtopic.php?t=2033

So, if we were to load up a "D" and an "N" model with the same amount of fuel, you would find that the performance of the "N" model far exceeds the "D" in every respect. (Combat weight configuration is with a full internal fuel load and the "N" model literally carried an additional 2,500lbs of internal fuel over and above what the "D" model carried.)


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## lesofprimus (Nov 20, 2005)

> So, if we were to load up a "D" and an "N" model with the same amount of fuel, you would find that the performance of the "N" model far exceeds the "D" in every respect.


I would agree with u Sal on that....


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## Gnomey (Nov 20, 2005)

lesofprimus said:


> > So, if we were to load up a "D" and an "N" model with the same amount of fuel, you would find that the performance of the "N" model far exceeds the "D" in every respect.
> 
> 
> I would agree with u Sal on that....


So would I.


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## SUperflanker37 (Nov 20, 2005)

I'm definitly a fan of the Corsair, from the simulators I've played at, the Corsair is just easier to fly, a bit speedier when it comes to responding to controls, and easier to maneuver. I suppose I'm just a fan of the lighter airframe.. don't get me wrong the P-47 was awesome too.. I just think it's better suited for a ground attack role than air-to-air.


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## Nonskimmer (Nov 20, 2005)

I wouldn't be too quick to base an opinion solely on computer games. More often than not, they haven't been found to quite accurately depict the aircrafts' handling characteristics. Some of them don't even come close.

However if gaming is your passion, we do have a gaming section here on the forums. You can discuss IL-2 Sturmovik, CFS, European Air War, LOMAC, or anything else you wish.


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## DerAdlerIstGelandet (Nov 20, 2005)

Agreed NS very well said.


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## Nonskimmer (Nov 20, 2005)

Danke.


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## DerAdlerIstGelandet (Nov 20, 2005)

Bitte, Klein Problem. 8)


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## SUperflanker37 (Nov 20, 2005)

yeah there are a good deal of games that arent realistic. have any of you flown before? hehe.. ill confess im only 14, so i really dont know a TON on what im talking about.. but it is an interest of mine


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## DerAdlerIstGelandet (Nov 20, 2005)

No sims are realistic eneogh to recreat the whole flying experience.

I fly. I have a private pilots liscence and I crew Blackhawk helicopter for the US Army. I only have about 70 hours including my flight training in Cessnas and I have almost 1500 flight hours as a Crewchief in Blackhawks.

FBJ flies also. He has alot more flight experience than I do.


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## lesofprimus (Nov 20, 2005)

And evan flies and glider flies and syscom flies and I used to fly ect ect ect.. lol


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## DerAdlerIstGelandet (Nov 20, 2005)

There are plenty of people on here with actual flight experience.


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## JonJGoldberg (Nov 20, 2005)

Reply to Sal Monella >>>

Combat weight: Suppose for the moment we change 47 to 51 so that it is now a P-51D against a P-47N. Using your argument (of both aircraft fulfillng the same role, you would not use a far larger and heavier fuel load in only one aircraft and since it would be impossible to load up the "D" with internal fuel to match the "N", you must do the reverse or reduce the internal fuel load of the "N" to match the "D".) you feel it fair to apply yet another advantage to the ’47N. I think not. Rather start at combat weight. Too much fuel, OK, the lets put both fighters at 50% fuel. This to me seems more rational, fair.

2”: I can not ‘quickly’ find reference as to why there is a 2” discrepancy in the data between P-47D N lengths. You may be correct, they may indeed be typos. My memory; however seems to tell me that it was done to reset CG due to the increased mass behind CG of the wheels. However I repeat, unlike the 8” extension between B C, where documents are easy to find, I can not find a document with a reason. Wish I could ask Alexander Kartveli. 

Reply to all >>> I'm not getting into another sim debate here...


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## DerAdlerIstGelandet (Nov 20, 2005)

JonJGoldberg said:


> Reply to all >>> I'm not getting into another sim debate here...



Good because it has all been covered and disproven.


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## lesofprimus (Nov 20, 2005)

Yep...


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## Gnomey (Nov 20, 2005)

That it has Alder...


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## Sal Monella (Nov 20, 2005)

Jon, I would in fact agree with you that if we were comparing the P-51D against the P-47N, it would be a fair comparison to load each up with an equivalent fuel level to carry each plane the same distance.  

In keeping with this logic, we would not start the P-47 "D" and "N" models at 50% fuel for the same reasons I have already explained. The internal fuel capacity of the N is truly massive. *In fact, the P-47N needs only 64% of it's internal fuel capacity filled to equal the same fuel load that a P-47D would have with 100% if it's internal fuel capacity.* Thus, lowering each aircraft's internal fuel load from 100% which is what you started with to 50% which is what you are now advocating is merely a restatement of the same problem on a different scale.

See Davidicus' post of June 18, 2005 on page two of the thread linked below. He took his data directly from Republic Aviation performance manuals.

http://www.ww2aircraft.net/forum/viewtopic.php?t=2033&postdays=0&postorder=asc&start=20


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## JonJGoldberg (Nov 21, 2005)

Reply to Sal Monella >>>

Thanks for the lead. I followed the jousting for a while, but disagree with the tact. I understand your point, but find it seriously flawed:

(1) In order to argue with you, possibly all the members here on this issue, I would 1st have to concede that your point, of putting in only the amount of fuel, bullets required for our mock combat, to be a valid one. I do not, but let’s go with it for a moment… In all the bantering back forth about the ‘exact’ data, how much fuel is actually required, everyone is forgetting that these aircraft were designed to perform at somewhere between combat normal weights (to my discovery recently as well; you see for the 1st iteration of my tables I used data of empty aircraft to generate performance figures, until Cheddar Cheese asked what happens when the pane is loaded…). By the numbers, at sea level a P-47N @ 50% fuel from Combat weight, is at its Max Designed Performance Weight. With less than that amount of fuel, the gained performance in turn roll rates are beyond the abilities of the airframe; period. See a very much simplified Chart 1. So although my 50% fuel from Combat weight seems arbitrary, in fact, as shown in Chart 1, applying 50% fuel from Combat weight for each aircraft does not simply reduce the scale of the difference, it should, in general, bring all aircraft, during this era, give or take, within their optimal performance window.

(2) Since we agree my argument is valid with regard to a P-51D Vs a ‘47N, I offer another twist… To compound: suppose that I now change the aircraft to a P-51D, a ‘47D. How do you apply your rule? My offer stays the same. From combat weight, change the fuel to 50%. Why does your rule change from comparison to comparison, and mine remains consistent? …I know, because I’m consistently wrong. Look forward to your reply.


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## JonJGoldberg (Nov 21, 2005)

By the way, my fighter tables can be found here >>> http://www.ww2aircraft.net/forum/viewtopic.php?t=962&postdays=0&postorder=asc&start=460

I Have A Typo on Chart 1; the Magenta Bar, which should read 'Vne Max Speed Limit'.


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## Sal Monella (Nov 21, 2005)

Jon, 

Huh? I have no idea where the data in "Chart 1" came from. But here's another chart which I have aptly entitled "Chart 2".
--------------------
Chart 2

Jon is wrong

Sal is right.
--------------------

As you can clearly see from the chart I have provided above, you are quite wrong. 

As to your second point, both of our comparisons are in fact constant. Yours uses the constant of either (1) full 100% internal fuel load or (2) 50% internal fuel load while mine uses the constant of (1) equal range which imposes the fuel load. 

You said that, "Why does your rule change from comparison to comparison, and mine remains consistent?" 

How is it that yours is a "constant" while mine is not? (Yours in fact involves a different fuel load for each aircraft as well as each aircraft will have a different internal fuel capacity.) Both of ours use a "constant" mathematical formula to determine fuel loads. Yours uses 100% internal or 50% internal capacity even though the capacities between aircraft vary considerably. Mine uses a "constant" mathematical formula based on range where the respective fuel loads are determined by that range. 

How is my "rule" as you say, changing? Impose an equal range limitation on each, fuel up each aircraft to meet that range requirement and that's the fuel load. 

Otherwise, you have a situation where in a comparison between a short range interceptor with a very small internal fuel capacity and a long range interceptor with a large fuel capacity, the short range interceptor will always appear to have a tremendous advantage in performance even though when they meet, each might very well be carrying the same fuel load because the long range interceptor had to fly a long distance to the area where the short range interceptor is still operating with a full tank. The actual performance between these adversaries at that point might very well favor the long range interceptor because it has shed much of its fuel load and weight.

The disagreement between us Jon is really quite simple. You believe it is more fair to impose an equal percentage of internal fuel capacity while I believe it is fair to impose an internal fuel capacity based on equal range. 

In it's internal tanks, the P-47N literally has the capacity to carry an additional 2,500lbs of gas than a P-47D carries. Under your "rule" with the information you presented in your earlier post, the climb rate of the "D" is equal to the "N" with the "N" carrying an additional 2,500lbs of fuel. (For a mental illustration of just how debilitating an extra 2,500lbs can be, imagine what would happen to the climb rate of the "D" if you added a 2,500lb bomb load in addition to having its tanks topped off.)

Anyway, you and I have a difference of opinion on this and that's OK.


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## CurzonDax (Nov 21, 2005)

One thing on all of this, when it comes to air to air victories, one can only make the comparison in the PTO. In the ETO the Corsair never engaged the Luftwaffe in combat.

:{)


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## elmilitaro (Nov 21, 2005)

The P-47 because of ...everything it had and did.


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## JonJGoldberg (Nov 21, 2005)

Reply to Sal Monella >>>

I left the door open to you for something a bit more creative…
You seem not able to understand the chart, /or question its validity origin even though the ‘how-s’ ‘where-s’ are visible, I drafted it; sorry it messed you up so… Surprisingly great response, your Chart 2; I knew when I wrote the last post, you would answer this way. Look back at it; in the 2nd 3rd to last lines I wrote > “Why does your rule change from comparison to comparison, and mine remains consistent? …I know, because I’m consistently wrong." <

I’ll respond to the second part, as a last ditch effort, but concede, once again, in advance that I’m always wrong…

You wrote >"How is it that yours is a "constant" while mine is not? (Yours in fact involves a different fuel load for each aircraft as well as each aircraft will have a different internal fuel capacity.) Both of ours use a "constant" mathematical formula to determine fuel loads. Yours uses 100% internal or 50% internal capacity even though the capacities between aircraft vary considerably. Mine uses a "constant" mathematical formula based on range where the respective fuel loads are determined by that range." <

The instrument of my calculation can be found on every aircraft. It’s called a fuel gage. …Funny that each aircraft’s fuel gage, regardless of type or subtype under ‘comparison’ knows where to find my ‘set point’ without using a ‘formula’. That’s what I call consistent! Sal, you are ‘consistently’ using an ever changing mathematical formula you label constant… Riddle me this Batman… At what ‘constant’ speed are you determining this range; change planes is there a new ‘consistent’ speed; at what ‘constant’ height; what’s the ‘constant’ weather like, what if I have to go around a storm; do we fly together, or meet in the middle… I could continue… But I’ll end this way… I’ve yet to see your gage, what do you call it?

Another hint of truth... I don't want to fly around, I just want to dogfight. How do I do this your way... I know, fuel up with 200 miles worth of god only knows at what speed, height, fuel. If you run out of gas, press reset.

Glad we can agree to disagree. 
Thanks for your time.


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## evangilder (Nov 21, 2005)

While your efforts to try an quantify some magical formula to determine some aircraft better than another are interesting, there are things that just cannot be quantified with charts and graphs. To arrive at a definite answer is highly improbable. 

Remember quite some time back, you accused me of romancing the stats and not looking at the facts? Isn't this kind of what you are trying to do with these tables? Yes, it is good information to compare, but when it all comes down to brass tacks, there is no formula to determine one WWII aircraft better than another.


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## JonJGoldberg (Nov 21, 2005)

Finally, sombody is seing something!!!!! You are 100% correct, in my opinion. I created these tables, simply to clarify this issue of 'stats' vs 'history' as it were. My argument, that the canditate should be judged according to history still remains, I put them in the 'blue box'. They are indeed just stats, further, my twist on those stats (not that I pre-judged the outcome, just how I assembled the weighting of them, combined thier gun performance with the flight performance). Thank you for finally realizing. Believe me I hope you all find them useful, as they indeed contain a lage amount of very hard to find data; this is why I left the math cells visible.

Good call.


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## Sal Monella (Nov 21, 2005)

Jon, my "Chart 2" was an illustrative demonstration that charts don't mean jack shit. I too am sorry that my chart messed you up, or, should I say, just messed with you.

Where did you get your raw data from for the P-47? As you are well aware, garbage in, garbage out. Regardless of your points about the ease of just pegging the fuel tank at full or half, I am convinced that comparing the "D" and "N" models in such a fashion isn't a fair comparison due to the extra 2,500lbs of fuel carried by what is essentially a high performance version of the same aircraft

Turning to the data that populates yourt charts, again, where does this data come from? How did you arrive at the figures you are listing?

I have a bunch of specifications published by Republic Aviation and official Technical Orders that frankly differ from the data you have presented.

I don't have the time to go through all of the errors that literally litter your tables. For instance, your listed "combat weight" and initial climb for the P-47N-25 are WRONG. (And I will go with Republic Aviation's published data over whatever source you are relying on Bubb.) And where the hell exactly did you get data for your various turning speed data? 

The "combat weight" is actually 16,330lbs.

The climb rate at 5,000ft ("combat weight") is 2,950 fpm. Sea level would be higher. (72" HG)

Top speed at critical altitude (32,000ft) is 453mph. ("combat weight" and 72" HG)

Like I said Jon, garbage in, garbage out. 

You are apparently focused on developing relative performance values for some kind of sim. We've all played sim games that bend the envelope in unrealistic ways. That's how it happens Jon. Bad data into the computer and unrealistic performance in the sim. Time to put down the greasy joystick and read some big boy books. 

By the way, just to show that there are no hard feelings, I'd be glad to correct your data for you. Just ask - nicely.


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## JonJGoldberg (Nov 22, 2005)

You know, before I start, everything with you is where does your data come from. I post where it comes from all the time. I have nothing to hide… However, once again Sal, for you, I’ll go backwards…

47D-23 Prop Climb:

http://www.xs4all.nl/~fbonne/warbirds/ww2htmls/repup47.html#repup471
Although specifically for D-22 (This site asks that nothing be reprinted) some climb rate Specs.

http://home.att.net/~jbaugher1/p47_4.html
Joe puts the climb rate at 2750ft/min, but >>> “Beginning with production blocks D-22-RE and D-23-RA, a larger (13- foot diameter) paddle-bladed propeller (either a Hamilton Standard Hydromatic 24E50-65 or a Curtiss Electric C542S) was fitted to make full use of the additional power provided by water injection. It added 400 feet per minute to the climb rate, but during landings and takeoffs there was only a scant six inches of clearance between blade tips and the ground. Takeoffs and landings must have both been hair-raising.”

http://www.cradleofaviation.org/history/aircraft/p-47/7.html
From what must be a ‘Sal’ approved site, as you sent me here >>> “Many of the Fighter Groups flying the P-47 in June of '44 were still flying some of the older "razor back" models with the framed canopy. These included the ultimate "razor back", the P-47D-23-RA. This Evansville built fighter was equipped with the latest Curtiss Electric paddle blade propeller. Of all the D models, this one was the fastest and best climbing.” 


These are but a few for the prop climb thing; at least ones that *ucked up Einstein can give you instant gratification for (You must have edited all of this from your post, as these refrences are now missing; good catch).

The N stats:

Maybe I should not have mentioned the Cradle of Aviation, your referenced site, this is also from your referenced article >>> “J model was an especially good climbing fighter too. It had a climb rate at sea level of 4,900 fpm. At 20,000 feet, it was still rocketing up at 4,400 fpm, and got there in 4 minutes, 15 seconds.” 

http://www.xs4all.nl/~fbonne/warbirds/ww2htmls/repup47.html#repup471 
See the section on the N variant.

http://home.att.net/~jbaugher1/p47_13.html
Performance of the P-47N-5-RE included a maximum speed of 397 mph at 10,000 feet, 448 mph at at 25,000 feet, and 460 mph at 30,000 feet. Initial climb rate was 2770 feet per minute at 5000 feet and 2550 feet per minute at 20,000 feet. Range (clean) was 800 miles at 10,000 feet. Armament included six or eight 0.50-inch machine guns with 500 rpg and two 1000-lb or three 500-lb bombs or ten 5-inch rockets. Weights were 11,000 pounds empty, 16,300 pounds normal loaded, and 20,700 pounds maximum. Dimension were wingspan 42 feet 7 inches, length 36 feet 4 inches, height 14 feet 7 inches, and wing area 322 square feet.

I grow very bored reproducing data for you, especially since some of it is dead on in one place not in others. This problem is I feel going to be like the 2” debate... All data that I used on the tables within my tables are as accurate as I could find, seem acceptable to all but you. Wmaxt Jabberwocky had some issues, as they are Lighting nuts, as you seem to be a ‘Bolt nut, but they are in agreement that my data is close enough; not that Lighting info has anything to do with ‘Bolt info.

As for the turn data: There is no turn data available, that I know of, and yes, in this regard, ever since I bought CFS-2 (1998) I’ve been trying to acquire as much turn data as possible to implement within that sim, for my own enjoyment, a few screen shots.

Jerry Beckwith is the author of the Flight Dynamics Workbook, the spread sheet I use to create the turn performance data with. The sheet is available @ www.netwings.org, as it says in the flight performance tables, Chart 1. 
From the Workbook >>
The Flight Dynamics Workbook has been designed to create flight models with accurate speeds, climb, roll, and turn rates. The Flight Dynamics Workbook automatically calculates air file parameters using the physical dimensions and performance characteristics of the original aircraft. The Workbook uses NACA wind tunnel data to calculate lift and drag parameters for the airfoils. The engineering data and formulas used to calculate propeller efficiency, climb rates, roll rates, and stability parameters were drawn from the NACA database as well.
The underlying principle of the Flight Dynamics Workbook is to calculate air file parameters based on the physical characteristics of the real aircraft. The following paragraphs describe the degree of accuracy can you expect from the Flight Dynamics Workbook. 
Speed at Altitude
The maximum speed at sea-level and maximum speed at high altitude will be within 1% of the performance figures entered in the worksheets. The maximum airspeed will occur at the correct altitude, and the airspeed at any other altitude will be less than the maximum speed. 
Climb Rate
The climb rate will be within 1% of the performance figures entered in the worksheets. Climb rate measurements depend on initial altitude and airspeed, test weight, time measurement interval, and pilot skill; results can vary significantly from test to test. 
Roll Rates
The maximum roll rate will be within a few percentage points of the specified roll rate and the speed where the optimum roll rate occurs will likewise be within a few percentage points of the target speed. The same can be said for the measured roll rate at other airspeeds as well. Roll rate performance depends not only on altitude, but also on the aircraft's angle of attack; so pilot skill has a significant impact on test measurements. Roll rate is very difficult to measure accurately; test results will vary significantly from test to test. 
Turn rates 
The Flight Dynamics Workbook calculates turn performance in terms of g-force vs airspeed - which tells you how fast you can go without stalling, turn rate in degrees per second vs airspeed and minimum turn radius vs airspeed. 
Lift coefficients, weight, and wing surface area are used to predict potential and predicted actual turn performance. The performance of properly tuned flight models will match the Workbook's predictions. 
Actual turn performance data for WWII vintage aircraft is very difficult to obtain. To date, turn performance data for only one aircraft has been located, the P-51D. This data was within 5% of the performance calculated by the Workbook.

Back to my own words. I modify his results some-what, but this can not be done within his workbook, instead, I modify the results in my own Excel spread sheet. You are quite right with regard to junk in > junk out, so yes I would be interested, in actual numbers, if you have them. I will insert you as a source, as I did with Jabberwocky, or if like some info from I do not agree with, I will note them within the tables, such as the two that now exist.


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## JonJGoldberg (Nov 22, 2005)

Reply to Sal Monella >>>
I finally found the stuff that was cut from the best fighter thread, that I had posted about sims... Look here http://www.ww2aircraft.net/forum/about3084-0-asc-120.html


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## CurzonDax (Nov 22, 2005)

Agreed on this info. In my experience a sim is just that, a sim. You can sim sim sim but it will not take over from actually flying these aircraft. The Corsair for example was not an easy plane and a sim just does not compare. I don't think the sims are probable, they are a sim. It is am imitation and a imitiation is not reality. Therefore comparing the performance of an aircraft reality vs. sim is incorrect and historically inacurrate.

:{)


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## wmaxt (Nov 22, 2005)

John has tried to quantify the data from 20+ aircraft into a model that can be compared. Jon has tried to keep it as accurate as possible. Many /most of us havs stuck to one or a few aircraft simply because we can't cover them all, Jon, has given us a starting point.

The point I found most interesting is how close the top 10/12 aircraft were (not including the P-47N which had limited contact with most of the top 12).

In his comparison the P-51 was 8th, add tactics, training, and numbers and it was very effective in the ETO, showing how much more beyond the chart there is to consider. 

As for sims, I think you may be confusing the sim experiance to the accuracy of the sim model. no they aren't reality but as Jon pointed out sims can accurately quantify the performance envelope of any aircraft. On the other hand a creative pilot can expand that envelope from there. 

wmaxt


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## Jank (Nov 22, 2005)

This disagreement that has come up is nteresting. Reading back I see that it began when Mr. Goldberg said that the P-47D-25 would be a better match against the F4U-4 than the P-47N.

I for one am not convincved.


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## JonJGoldberg (Nov 23, 2005)

Reply to Wmaxt >>>

Thanks for your continued support. I’m having a little trouble understanding your reference to the ‘47N in the 2nd paragraph though. 

I’ve just had time to go through the accident reports you set me a while back; you should repost the link. Seriously eye opening; GRRRREAT stuff!! Maybe the Lighting wasn’t as expensive as I originally thought. I wish data like this was available for all aircraft in the tables; I’d work on figuring out how to include this info...

Reply to Jank >>>

Believe it or not, for the most part I was enjoying the fencing, but unfortunately, somehow, for me it was the post of Chart 2, as for my part maybe it was my reply to Chart 2, words started to be directed to the individual/s, as opposed to the topic/s… Although entertaining for you, as for my part I apologize for the personal remarks.

I had posted the following, with regard to the D Vs the N > “In reality the N indeed defeats the D. In my tables N indeed defeats the D. But we are not talking reality here, as the two never fought (F4U vs. P47, or P47vs P47). So I'm taking this posture, D as opposed to N, for the following reasons... @ combat weight, on production versions, the D's superior turning rate climb combined with it's level stall characteristic on my personal dogfighting scale, defeats the D's roll speed advantage.” <

I made a typo, the last words should have said, …@ combat weight, on production versions, the D's superior turning rate climb combined with it's level stall characteristic on my personal dogfighting scale, defeats the N's roll speed advantage.”
Now since you need convincing… I’ll expand:

1st I need to qualify something… I’m not a pilot. I served in the USAF as a sheet metal mechanic, took flight lessons then (1980), and rode in the trainee’s seat a few times in T-38s, but never got a license, they say I’m color blind. Now, at 45, the closest I’ve come, I’ll ever come to dogfighting for ‘real’, like most (obviously not all) of us, admitted or not, is in a sim. You read my sim post, I imagine, so you know I know the sim is not real (I like to think it is at times), but like these letters I’ve combined into words, using them in a manner that allows a simulation of talking with you, I’ve tried for years to make the aircraft respond as they would, this is not to say that they are indeed real, much like the fact that you can not hear the cadence of my speech; however to me, the meaning of the ‘stat’ is portrayed in a much more convincing manner than simply the numbers, stats, figures, ‘unanimated’ staring back at me on a piece of paper, or screen. Perhaps we may all accept, one day, that a sim, like a video is not real, like these words, any words are not ‘real’, but they all can, when properly used, do a dam good job of helping us understand what happened/s in reality. Finally…

OK the promised expansion… I imagine the ‘meeting’ of the contestants, the ’47? F4U-4 to be one on one, a dogfight, as a joust between the two is a draw, or at best, luck. Accepting the dogfight scenario (simulation), low speed attributes outweigh high speed attributes. I consistently read that WW2 dogfights happened at speeds centered around 200 to 250, depending on the year, combatants. This is not to say that the initial contact was made at that speed, only that the ensuing dogfight happened at that speed. No matter the praise each advocate has for their respective mounts, no actual WW2 Corsair pilot, no T-bolt pilot has said in print that their plane was a dogfighter, at least not one I have seen; with the exception of an article I found at (http://home.att.net/~historyzone/F4U-4.html), written in praise of the F4U-4, which says it was indeed amongst the best dogfighters of the era. At these speeds, the N no longer has a ‘speed advantage’. The N’s semi-laminar flow wings perform best at speeds above 250, and without these high speeds, it’s performance decays faster than the D’s decay. I know that some question my tables, but for now, it’s the only document we all can have, check it out. http://www.ww2aircraft.net/forum/viewtopic.php?t=962&start=520


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## DerAdlerIstGelandet (Nov 23, 2005)

Interesting conclusions there. I have enjoyed reading all of this. I have not said much because I am just trying to take it all in. Seriously very interesting stuff, all of you.


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## syscom3 (Nov 23, 2005)

It certeinly is an eye opener to see the info.

I salute Mr Goldberg for actually trying to quantify what plane is best. Plus there is a lot of constructive arguments coming from several people to keep the topic on course.

This is almost like seeing a thesis being generated by a student then dissected by experts.


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## DerAdlerIstGelandet (Nov 23, 2005)

Yes I agree with you. At the same time though I do not believe that charts, graphs, numbers, and sims can accuratly tell you what aircraft was the best.


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## FLYBOYJ (Nov 23, 2005)

Yep- Mr. Goldberg I commend you!


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## Sal Monella (Nov 23, 2005)

Jon, 

When I keep saying, "Where did you get your data?", I am really making a point like, "Did you pull that out of your rectum?" or Did you just plug in "P-47" into your web search engine and write down what came up?"

Garbage in, garbage out. You will notice that the various websites you have cited to are inconsistent with each other and at variance with the data I have provided below.

We still disagree on comparing the combat weight P-47N against the combat weight P-47D-25 or any other "D" model for that matter as the P-47N is carrying an additional 2,500lbs of fuel over the D-25's capacity. The D-23, by the way, had an internal fuel capacity that was 100 gallons less than the D-25 so there was an even greater fuel differential between the "N" and D-23. 

I erased that comment about the D-23 not having the paddle blades because I remembered that I was wrong. Your data on the climb rate of the D-23, however is still in error, It was 2,920fpm. It had a greater climb rate than the D-25 because the D-25 was burdened with an extra 100 gallons of fuel in its internal tanks.

At any rate, in the interest of accurate information, I invite you to modify your charts to reflect the following where appropriate, or to take notice where the outputs from your data does not reflect the facts in the following data.

Wing area is 322.7sqft. ("D" model is 300sqft)
Length is 36'3-1/4"
Wingspan is 42'8"
Height is 13'7"

The total aileron area is greater than the "D" by 2.27sqft ("D" model is 25.7sqft)
The total wing flap area is greater than the "D" by 6.4sqft. ("D" model is 39.6sqft)

Empty weight is 10,998lbs. Combat weight is 16,330lbs. (Yes, those number are correct. Hopefully, you can see my point now.) Maximum takeoff weight is 21,198lbs. If we were to load up the "N" with the same internal fuel load as the D-25 model, it would weigh 13,850lbs. 

Top speed at 32,000ft at combat weight and 72" HG is 453mph. The "N" can in fact do 467mph, just not while carrying a full internal fuel laod. The 467mph figure that is widely referenced is with an internal fuel load equivalent to the D-25 (100 gallons greater than the D-23). At 5,000ft, at combat weight and 72" HG, she can do 371mph. 

The climb rate for the "N" at combat weight (16,330lbs) at 5,000ft and 72" HG is 2,950fpm. This is no small feat. The P-47M with a full internal fuel load (equivalent to the D-25) weighs just 13,275lbs. It can pull 3,775fpm at 5,000ft and 72" HG.

If the P-47N were to be loaded up with a fuel load equal to the "M" and D-25 (100 gallons greater than the D-23), I have no doubt that it would climb at 3,650fpm as it would weigh just 575lbs more than the "M" and has a greater wing area.

The "N" at a fuel load equivalent to the "D-25" would out turn any "D" model as it has a significantly more powerful 2,800hp engine and a greater wing and control surface area. The D-25, in combat weight, weighed in at 14,247lbs which is heavier than the "N" model with the same ammunition and fuel load (13,850lbs.)

Lastly, here is a tidbit that I would venture no one on this board is aware. The "N" model was designed to carry, in place of external fuel tanks, up to 3,700lbs of bombs!


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## JonJGoldberg (Nov 24, 2005)

Reply to Sal Monella >>>

This has been fun, try your best to stop making this personal, my sphincter, and what I do with it is not open for discussion here, I believe there is a thread for off topic things, where you may be able to satisfy your newly found interest. Please note, as I have not posted anything there, all data has been extrapolated using the best available models.

More on topic, I feel we are getting to be repetitive… but I have a new angle for ya…

This time, in effort to beat the eraser, I’ll start from where you started: Like most of us, it seems we must each edit data that is available. We all must extrapolate the data we find. I tried to point this out using the Cradle of Aviation article you asked I read. I posted the info given for the XP-47J to show that we all (yes including myself) are guilty of being able to slant, ever so slightly taint things ‘our way’ even when we know better. A better example (within Sal approved data) I can not, as of yet, find; how in the world (of sim reality beer) can an aircraft, whose best climb rate, taking what was printed at face value, be 4,900 ft/min @ SL 4,400 ft/min at 20,000 ft reach 20,000 in 4min 15 sec.? Want to know; Mother Nature has an opinion, guarding the ’47, as it was her favorite plane of the time, she aided the craft with a well placed blast of her nostril… There fore defeating the best mathematician at there own game as she hates being quantified. So yeah, I decipher what I see, as you do. Take your beloved service manual, better yet, the service manual for a T-38 (I choose this aircraft as it is not a fighter; an aircraft whose service manual, I’ve seen, OK about 20 years ago, but I saw it, I figure represents both neutral ground, higher level of production). On the flight line, there was not a single pair of aircraft that exactly matched. When they left the factory, each was slightly different, they are built using jigs, by people. The sheet metal skins never had the rivet holes in exactly the same place. Replacement parts were/are in field tailored from their ‘factory’ stampings to exactly match their intended recipients. As a matter of fact, the factories normally produce these pieces (skin) ever so slightly different than original to allow ‘fitting’, or they are remanufactured in field using measurements from the donor for this reason. So with regard to the spec within your service books; it seems you expect my data to match yours exactly. It can’t. Mine was taken from serial number ‘x’ and yours from ‘y’ it says so on the cover of my service manual. My plane is 158 lbs heavier than yours, at combat weight, climbs 180 ft /min slower, goes 11 mph faster. All these numbers seem just impossible to you, just ‘plane’ hogwash. You are entitled. As for me, the worst number here may be the climb rate; ((180/2900)*100) I’m off 6.2% from your bible, that, according to you, is just completely out of the ball park… your sending the clean up crew after the ‘litter’. Mind you, I’d take a 6.2% improvement in my income, so this number is significant, to be sure, but it is hardly grounds for dismissal; we should be able to work on this together, as I’m willing to ‘fix’ my data; please just send me a copy of the original, or point me as to where to acquire it, I left E-mail address, you can see them in my profile. No more slander OK, the data is not WRONG, your data is not wrong. Climbing to 20,000 ft in 4min 15 sec, in an aircraft whose best climb rate is 4,900 ft/min, that’s wrong.

For a closer look at how combat weight within my tables are determined: I started with 10997 lbs (funny, practically the same number, somebody please fill the tires), to which I added a 225 lb pilot, 75 lb radio, 30 lbs fudge factor (maybe the pilot naked is 225, maybe the radio weighs more, maybe there was 5 gallons of gas stuck from the last flight), 529 lbs of guns (M2=66.1 lbs), 1296 lbs of bullets (5.184 oz/round) @ 500 rpg 3336 lbs of fuel (6 lbs per gal/556 gal). This brings me to my ‘combat weight figure’. I propose your Republic book I have one or more of the following happening, we have different pilots in mind, or a different amount of ammo.

As for the rest of my numbers, again they do not exactly match yours, we may argue about .3 sq foot of wing area, a ¼ inch in length; I feel as if this would not warrant a letter home to mama, you feel as if they disqualify my stats. OK.

But Sal, I have hope in you. 

On Match Rules: We’re going to race a semi, against a pick up truck at a drag strip. These two anonymous vehicles, although designed for clearly different purposes have in common the ability to tow a 14’ power boat on its trailer, my intended ‘job’ for these vehicles, a sales man. I’ve told the salesman, who’s paid by commission, to apply my deposit on the victor, as beside towing the boat, I want as much acceleration as I can get, that’s what I want; of all the vehicles here, it’s between these two. Now the semi is 10 times the price of the pick up, so the commissioned sales man says, hey Einstein (or bub), tell you what I’m goanna do, I’m goanna make this fair. The semi is currently equipped with 4 extra tires, 1 extra axel, a hitch that weighs a lot more than is required, it’s got the capacity for all this extra gas. Now I promise that you will receive all of the features capacity of whichever truck wins, but I’m goanna take all this unnecessary stuff off, just for this race, so that you may more properly judge the results. Now it’s clear that I would not accept these terms, further it’s clear what the objectives are all around. I find the race as probable as our dogfight, we each see the other as the salesman. I’m not convinced that I’m in any way handicapping the semi, by requiring the salesman to keep the vehicles as they are, feel it wasn’t be proper for the salesman to suggest loading the pickup with 4 semi tires, axel, and fuel tanks, as either which way, I’m screwed! …So much for your bomb analogy.

Happy Bird Day To All


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## FLYBOYJ (Nov 24, 2005)

JonJGoldberg said:


> Take your beloved service manual, better yet, the service manual for a T-38 (I choose this aircraft as it is not a fighter; an aircraft whose service manual, I’ve seen, OK about 20 years ago, but I saw it, I figure represents both neutral ground, higher level of production). On the flight line, there was not a single pair of aircraft that exactly matched. When they left the factory, each was slightly different, they are built using jigs, by people. The sheet metal skins never had the rivet holes in exactly the same place. Replacement parts were/are in field tailored from their ‘factory’ stampings to exactly match their intended recipients. As a matter of fact, the factories normally produce these pieces (skin) ever so slightly different than original to allow ‘fitting’, or they are remanufactured in field using measurements from the donor for this reason.



Just to ping off JJs comments - although aircraft from WW2 to today's fighters are mainly built up in assembly jigs, once in the field they tend to "grow" in one direction or another. Its very hard to use a cannibalized skin from one aircraft to another because rivet holes will be slightly off. Any time skin repairs are accomplished, the preferred method is to manufacture a "blank" sheet line it up where it should be and "back-drill" the rivet holes using the existing structure as a template.

Anytime you start changing major structural components in the field because of damage, especially damage that placed large loads on the airframe, the aircraft will never be the same. Many times it will possess some abnormality ( flying crooked, requiring more trim in a certain configuration, not achieving the max speed as indicated in the flight manual). I've also seen "positive" results from major field repairs as well, but those are far and few....

JJ - I hope you don't mind me addressing you that way, being a former New Yorker, it only seems natural...

Reactions: Like Like:
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## JonJGoldberg (Nov 24, 2005)

Reply to FLYBOYJ >>>

JJs OK, You may...

You are 100% correct with your above post, about growth, repair... but I had a specific event in mind... I was stationed @ Edwards in 1981; we recieved two new T-38s for the pilots training school there. After the crew chiefs set the planes, they were to be refuled, sent on thier way within two hours. An APU truck clipped the left wing of one and the right of the other (the driver had a heart attack). It was suggested by the Sgt. in charge (I was an airman) to the commander, that in order to save time, the dammaged panel from the one with lessor dammage be replaced with the other's as they were new, less than 50 hour flight time on each, in that way we may be able to release one of them on time. Before removing the panel from the healthy plane, the dammaged section was placed on top; we wound up building the parts from scratch, as the devations were obvious. Not that I thought it was a good idea to begin with... The next day the T-38s were on thier way.


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## FLYBOYJ (Nov 24, 2005)

Edwards 1981? I used to live in the Antelope Valley. I worked on occasion at Edwards and used to fly there with the Aero Club. The whole area is a lot different today...


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## syscom3 (Nov 24, 2005)

I used to go four wheeling near Mojave in the 80's. California City to be exact.


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## FLYBOYJ (Nov 24, 2005)

Yep - Cal City, I used to fly there allthe time, they had cheap aviation fuel.


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## JonJGoldberg (Nov 24, 2005)

...Man that was a while ago. Last time I was back there was '95, on my honeymoon (We landed in Vegas, stayed two days, then for two weeks armed with a Caddy from Hertz, traveled from Vegas, to the Grand Canyon, to 4 corners, to LA, to SF and flew home from there) already things were different. Pomdale raceway had expanded, my Trailer Park the Drive In were gone... even the intersections at the wind factory (can't remember the name of where all those wind generators are) were busy. My favorite 'derelict' places were now accessible... I was pretty much a lost soul back then, guess I still am.


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## JonJGoldberg (Nov 24, 2005)

Come to think of it, my honeymoon was in '92, don't tell my wife of my mistake!!!


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## Sal Monella (Nov 24, 2005)

Jon, you said, 

"I posted the info given for the XP-47J to show that we all (yes including myself) are guilty of being able to slant, ever so slightly taint things ‘our way’ even when we know better. A better example (within Sal approved data) I can not, as of yet, find; how in the world (of sim reality beer) can an aircraft, whose best climb rate, taking what was printed at face value, be 4,900 ft/min @ SL 4,400 ft/min at 20,000 ft reach 20,000 in 4min 15 sec.? Want to know; Mother Nature has an opinion, guarding the ’47, as it was her favorite plane of the time, she aided the craft with a well placed blast of her nostril…"

The cut and paste job that I did on that site was as follows:

"The XP-47N took to the air for the first time on July 22, 1944. Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further. In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt. Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence."

As you see, there is no "J" data among any of the above. I recall mentioning the "J" and XP-72 in relation to the claim that you made that the P-47 wsa at the end of its design potential and mentioned the top speeds that these two aircraft could achieve. (I never broached the subject of climb rate.) Anyway, I cut and pasted that section from that website rather than just citing to the website in full because I was not in fact adopting all the data this site contains. Just the portion I cut and pased. I have a small part of the report or some other report that references it that mentions that mock battle that specifically says that they switched the pilots just to be sure that the outcome they were getting was really right. They expected the "N" to get, as was written, "clobbered."

As for that websiit that you keep referencing, you are using it too. Even though it contains information that you yourself are claiming can't be true. Hmmm. Could that be an implicit admission that the sources you yourself relying on contain garbage information? Oops.

So, to recap, if I cut and paste a section from a website, I am indeed vouching for the information I cut and pasted. I am ot vouching for any other information regarding dates, persons, events, etc.

As you the small section of a previous post that I erased, as I already pointed out, I removed it because I realized that it was in error. I could have left it up and posted after that that it was in error too. Six of one or a half dozen of the other. What is your point? Whether I erase something 10 minutes (literally) after I post it or make another post immediately thereafter, pointing out that something I wrote was incorrect, what's the difference? 

You said, "I’m off 6.2% from your bible"

That "bible" should be your bible too. Otherwise, as you have seen on the multitude of websites and publications, there is a lot of varying information out there and some of it varies an awful lot. If you just decide to choose the datat that you see cited most often, you run the risk of choosing data that just happens to have been used as source material more often than other erroneous material. I am relying on primary source material, hence your apt characterization that I am using a bible. It's time you got some religion Jon.

You said, "For a closer look at how combat weight within my tables are determined: I started with 10997 lbs (funny, practically the same number, somebody please fill the tires), to which I added a 225 lb pilot, 75 lb radio, 30 lbs fudge factor (maybe the pilot naked is 225, maybe the radio weighs more, maybe there was 5 gallons of gas stuck from the last flight), 529 lbs of guns (M2=66.1 lbs), 1296 lbs of bullets (5.184 oz/round) @ 500 rpg 3336 lbs of fuel (6 lbs per gal/556 gal). This brings me to my ‘combat weight figure’. I propose your Republic book I have one or more of the following happening, we have different pilots in mind, or a different amount of ammo."

I'm not going to drag out my stuff again but I can tell you right off the top of my head that your weight for the radio (actually, there are three of them) is WAY off. I suspect that there may be other errors in your assumptons on weights of various items as well.

You said, "So much for your bomb analogy."

What are you talking about? What analogy did I make concerning bombs?


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## DerAdlerIstGelandet (Nov 24, 2005)

JonJGoldberg said:


> Reply to FLYBOYJ >>>
> 
> JJs OK, You may...
> 
> You are 100% correct with your above post, about growth, repair... but I had a specific event in mind... I was stationed @ Edwards in 1981; we recieved two new T-38s for the pilots training school there. After the crew chiefs set the planes, they were to be refuled, sent on thier way within two hours. An APU truck clipped the left wing of one and the right of the other (the driver had a heart attack). It was suggested by the Sgt. in charge (I was an airman) to the commander, that in order to save time, the dammaged panel from the one with lessor dammage be replaced with the other's as they were new, less than 50 hour flight time on each, in that way we may be able to release one of them on time. Before removing the panel from the healthy plane, the dammaged section was placed on top; we wound up building the parts from scratch, as the devations were obvious. Not that I thought it was a good idea to begin with... The next day the T-38s were on thier way.



We canabalize parts for our aircraft all the time but we never use structural parts from another aircraft because of the reasons that FBJ said. If we need repairs like that made such as to the skin of hte aircraft we go to aircraft and they make us another "copy" if you will of the damaged piece. 

I am not saying anything about your situation that you talked about at Edwards in 1981. I am just saying from my experience what we do.

Damn I hope that came out allright.


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## JonJGoldberg (Nov 25, 2005)

Sal, seriously, Happy Thanks Giving. 

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm
As you see, there is no "J" data among any of the above. I recall mentioning the "J" and XP-72 in relation to the claim that you made that the P-47 wsa at the end of its design potential and mentioned the top speeds that these two aircraft could achieve. (I never broached the subject of climb rate.) Anyway, I cut and pasted that section from that website rather than just citing to the website in full because I was not in fact adopting all the data this site contains. Just the portion I cut and pased. I have a small part of the report or some other report that references it that mentions that mock battle that specifically says that they switched the pilots just to be sure that the outcome they were getting was really right. They expected the "N" to get, as was written, "clobbered."<<

In reply, I'll 1st use an old post of yours...

>>Sal Monella Posted: Sat Nov 19, 2005 10:49 pm 
Jon, with respect to your assertion that, "Fuel in the wings, and the fuselage extension did not benefit the '47's aerobatic performance; although the increased power, fuselage extension (2”), wing air flow improvements did increase its speed."

Please see http://home.att.net/~historyzone/Seversky-Republic8.html <<

With this posting, which neglects to describe 'limited endorsement', you took me to an article, labeled: _The Cradle of Aviation Series Presents P-47 Thunderbolt: Aviation Darwinism Chapter Eight_ I opened read the other chapters. In chapter seven you will find... _"The J model was an especially good climbing fighter too. It had a climb rate at sea level of 4,900 fpm. At 20,000 feet, it was still rocketing up at 4,400 fpm, and got there in 4 minutes, 15 seconds."_ I figure if you can cut paste the excerpt of your choice, so may I. I figure if you reference an article, I'm able to read it in its entirety. ...There I go, wrong again, as now you are only vouching for your excerpt; that’s OK, as you cement my point about having to filter out information (I made need this later), we now all see the same applies to you.

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm 
...the small section of a previous post that I erased, as I already pointed out, I removed it because I realized that it was in error. I could have left it up and posted after that that it was in error too. Six of one or a half dozen of the other. What is your point?<<

My points, there are 3: 1-You make mistakes, as do I; 2-You do not admit to mistakes, rather you erase them; 3-You had made some pretty colorful remarks towards me in those deletions, you choose not to display in light of your error. All within your rights to do; all a reflection character.

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm
As for that websiit that you keep referencing, you are using it too. Even though it contains information that you yourself are claiming can't be true. Hmmm. Could that be an implicit admission that the sources you yourself relying on contain garbage information? Oops.<<

Humm... Lets see how I 'referanced' (am using) this site; 1st my post:

>>JonJGoldberg Posted: Tue Nov 22, 2005 2:13 am
http://www.cradleofaviation.org/history/aircraft/p-47/7.html 
From what must be a ‘Sal’ approved site, as you sent me here: “Many of the Fighter Groups flying the P-47 in June of '44 were still flying some of the older "razor back" models with the framed canopy. These included the ultimate "razor back", the P-47D-23-RA. This Evansville built fighter was equipped with the latest Curtiss Electric paddle blade propeller. Of all the D models, this one was the fastest and best climbing.”

These are but a few for the prop climb thing; at least ones that *ucked up Einstein can give you instant gratification for (You must have edited all of this from your post, as these refrences are now missing; good catch). 

The N stats: 

Maybe I should not have mentioned the Cradle of Aviation, your referenced site, this is also from your referenced article: “J model was an especially good climbing fighter too. It had a climb rate at sea level of 4,900 fpm. At 20,000 feet, it was still rocketing up at 4,400 fpm, and got there in 4 minutes, 15 seconds.” <<

As for this site's info appearing on my tables, I can't seem to remember listing it...

>> ADDITIONAL INFO SOURCED FROM:
*Illustrated History Of Fighters; Editor Bill Gunston; Exeter Books 1983
*The Complete Encyclopedia Of World Aircraft; Editors Paul Eden, Soph Moeng; Aerospace Publishing 2002
*US Military Aircraft; Joe Baugher; Last revised: 20 May 2001; http://www.csd.uwo.ca/~pettypi/elevon/baugher_us/
*Aircraft Of The World; Joe Baugher; Last revised: 9 March 2001; http://www.csd.uwo.ca/~pettypi/elevon/baugher_other/
*USAAF Resource Center; http://www.warbirdsresourcegroup.org/URG/fighters.htm
* http://www.acepilots.com/index.html#top *http://www.warbirdsresourcegroup.org/
*The USAF Museum; http://www.wpafb.af.mil/museum/early_years/ey.htm
*Special thanks to Jerry Beckwith's work available at http://www.avhistory.org/
*Thanks to Jabberwocky://www.ww2aircraft.net/
*Francis H. Dean, America's Hundred Thousand: U.S. Production Fighters of World War II, Schiffer Military History, 1996 
*http://.ww2aircraft.co.uk *http://mig3.sovietwarplanes.com/yak3/yak3vk108/yak3vk108.html
*History Of the Royal Air Force; http://www.raf.mod.uk/history/ac_hist.html <<

...Nope not there. Must have forgotten to pick up the trash; Oops! In fairness, had I posted something from a web site, it doesn't mean that I go through the whole dam site, checking its references. We all have better things to do. But, if I reference an article, don't make note of where I the author may disagree, I try to follow this 'rule' forget sometimes too, I do expose myself, have been in the same circumstance you find you are in. However, how you handle being wrong, is more important than how you handle being right. So for examples, please view several exchanges between myself lots of members in the Best Fighter III section, at about page 17, or 18. See how I others have responded when faced with our mistakes misjudgments that we all make.

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm
You said, "I’m off 6.2% from your bible" 
That "bible" should be your bible too. Otherwise, as you have seen on the multitude of websites and publications, there is a lot of varying information out there and some of it varies an awful lot. If you just decide to choose the datat that you see cited most often, you run the risk of choosing data that just happens to have been used as source material more often than other erroneous material. I am relying on primary source material, hence your apt characterization that I am using a bible. It's time you got some religion Jon. <<

I reposed this not to reply to the religion thing, that stuff is for other sites; but to propose the following... I've repeatedly asked (nicely even as you suggested) for you to submit info from your service manual, send me a copy, or a .pdf. I would love to include 'more accurate data'. I believe the pilots manual to be a better source than the service manual, I have neither, will (gladly) accept info from either; if you send it to me I will indeed re-run the new numbers, repost a revision, name you as a source, fair? I have shared all of my data, posted it, defended it, displayed it. I make no money from it, charge nothing to those interested in its use. I have not posted it anywhere but here (@ ww2Aircraft.net) intend not to post it anywhere but here, as the members here are the ones who caused me to draft it, this site should benefit any residuals from the traffic that may be generated by people looking for it. Most have found the perspective to be at the very least interesting, others are using it as a starting point for their own assessments. That knowledge, knowing that others are using my work in this manner is my payment, my reward for this. Additionally, I receive information to construct better 'simulations' of these aircraft for my own enjoyment.

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm
I'm not going to drag out my stuff again but I can tell you right off the top of my head that your weight for the radio (actually, there are three of them) is WAY off. I suspect that there may be other errors in your assumptons on weights of various items as well.<<

My apologies, you are correct there are 3 radios, and this weight is for all 3, in total. Thank you.

>>Sal Monella Posted: Thu Nov 24, 2005 3:42 pm
You said, "So much for your bomb analogy." 
What are you talking about? What analogy did I make concerning bombs?<<

In reply, I'll old posts of yours...

>>Last edited by Sal Monella on Mon Nov 21, 2005 1:15 pm; edited 1 time in total
…(For a mental illustration of just how debilitating an extra 2,500lbs can be, imagine what would happen to the climb rate of the "D" if you added a 2,500lb bomb load in addition to having its tanks topped off.)

Seems I tuckered you out; sorry. Where I work, they say I’m one of the most difficult (anal) persons to argue with, that I should have become an attorney instead of the lighting intergration department head, high profile job designer programmer for one of the largest ‘smart house’ companies out there (I have a gallery I finished in Mexico City for my company coming to the Robb Report). I do not find the attorney comment a compliment, share this with you to show that you are not alone. I am quite a handful.

To wrap up, I believe we are posturing over ‘minor differences’. For example I believe I read somewhere (wish I cold remember the source, will post it if I do, or maybe others can help me here) that production differences were as much as this (6% performance differences when consecutive serial numbered aircraft were tested) from may aircraft factories. Please, once again send me data, I will update. The real deal is that I would like the data that appears on my tables to be as accurate as possible. I would like to be able to banter about history, as opposed to ‘specs’; I actually hate stats.

Reply To DerAdlerIstGelandet >>>
Yes, you got it right!!! As I gained more experience in the service, I came to learn how ridicules the offer was. It was the 1st thing that popped into my head as I was drafting the reply to Sal, I thank you FlyboyJ for the added comments; 'growth' should have been explained to Sal ( all of you) as well. As former sheet metal mechanic, I deserve some lashes...


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## Sal Monella (Nov 25, 2005)

Jon, 

Jon, you said:

"Sal Monella Posted: Sat Nov 19, 2005 10:49 pm
Jon, with respect to your assertion that, "Fuel in the wings, and the fuselage extension did not benefit the '47's aerobatic performance; although the increased power, fuselage extension (2”), wing air flow improvements did increase its speed."

Please see http://home.att.net/~historyzone/Seversky-Republic8.html"

Again, the excerpt itself makes no mention of any "J" data. Please note that the "Please see http://home.att.net/~historyzone/Seversky-Republic8.html comment referred not to what preceeded that cite but what came after which was the cut and pasted excerpt itself. Otherwise I would have just made a conclusory statement and added a cite which I clearly did not do. The purpose of cutting and pasting the excerpt was to point you to that very section of the cited material. Not anything about the "J" climb rate. Otherwise, in keeping with the precedent of my cut and paste, I would have cut and pasted the "J" data as well which I clearly did not do. The "J" climb data has no relevance in a discussion of the relative merits between the "D" and "N" or the accuracy of the "N" data that you are relying on aka "the garbage". 

You said, "As for this site's info appearing on my tables, I can't seem to remember listing it... "

You are right. My point that it was a site you sourced from is incorrect. However, my point about the absolute irrelevance of the "J" climb data which was NEVER referenced by me still stands.

Yes I make mistakes. Again, a half dozen of one or six of the other. I erased that small portion of my post within ten minutes of posting it so frankly, I don't see any foul. I could have left it up and made a follow up post but it's just easier to edit the existing post. Sorry of your feelings were hurt. I promise that if you erase something ten minutes after posting it because you realized that it is wrong, I won't get my drawers in a bunch. OK? As far as mistakes, I have no problem admitting to mistakes. I never said that I didn;t make those comments ten minuyes earlier before I erased them. Again, I think you'tr trying to make a case here about nothing. As for colorful comments, I think you're as moron. Happy? I promise I won't delete that. 

I am ot the one defending the use of data that I know is wrong. You have already made it clear that you feel that some of the differences that I have pointed out are too minor to make a difference rather than admit that your data is wrong, regardless of the margin. Why would anyone defend the use of data they know is incorrect? Why ekse would you make light of what you assert to be small differences? For the record, some of those differences aren't so small. Like your asserted climb rate being 2,770fpm when it's 2,950fpm. 

Just admit that your data is wrong. Do that without colorful references to filling the tires with air or referring to my data as having eminated from my "bible". Like I said, you should strive to collect yout data from primary source "bibles" as well. To do otherwise is intellectually lazy. This ain't rocket science. You can do this. Just get a hold of the correct primary source data and stop wasting energy defending garbage. Hell, your dimensional data is even incorrect!

Your several websites don't even agree with each other and none of them get it correct! Hmmm. Every one of your sites have conflicting informatrion but that shouldn't set off any warning bells - if you're not really interested in accurate data that is.

You said, " In fairness, had I posted something from a web site, it doesn't mean that I go through the whole dam site, checking its references." 

Well, how exactly, when you go through all these websites, do you select which data to use since many of the sources vary with each other? Some of them apparently even give rise to false memories. You crack me up. You read a typo (I think I was being too generous. I think it was probably just another instance of garbage data) regarding a difference in length between the "D" and "N" models and then suddenly have a "recollection" that the "N" model was lengthened 2" to move the center of gravity. You and I and everyone else reading our little exchange here know that that is a vat of bullshit. 

You have no such "recollection" because you have NEVER read or heard it anywhere. You made it up to support the use of your erroneous data because you can't admit that you're wrong. Talk about character. 

You said, "My apologies, you are correct there are 3 radios, and this weight is for all 3, in total. Thank you. "

Not so fast Mr. Magoo. Thank you for acknowledging that I am correct about the three radios but no, you are still WRONG on their weight. (surprise surprise) I don't have the "N" specs in front of me right now but I can tell you that the radios on the D-25 were as follows:

SCR-274N @ 82lbs.
SCR-522 @ 96lbs.
SCR-695 @ 54lbs.

That's a total weight of 232lbs. (The "N" had a HEAVIER total radio weight. Can you guess why?) Now I realize that 232lbs is not really that much different than 75lbs in the scheme of the entire aircraft's weight so I fully expect you to now argue that it's OK to use the 75lb data. By the way, where did you get that 75lb figure? Did you pull it out of your rectum too? 

I don't have the time to check item by item all of your other assumptions but I know that total ammunition load weights at different loadings is in my materials as well. I wouldn't place much stock in what appears to be your practice of multiplying the weight of a single round (As evidenced by your assertion that "1296 lbs of bullets (5.184 oz/round) @ 500 rpg) by the number of rounds. 

Excuse me but different types of rounds have different weights. An armor piercing round has a diferent weight than an incindiary round. In addition, your computation (which, I might add actually goes out to the thousanth of an ounce) fails to include the steel belt linkage weight as well.

And who told you thst an M2 weighs 66.1 lbs? More of that data that has been residing in your ass! It is 72.5lbs per gun on the D models up to D-25 and 68.5lbs for the M2's installed on the D-25 series onwards.

Lastly, you said on an earlier post, "By the numbers, at sea level a P-47N @ 50% fuel from Combat weight, is at its Max Designed Performance Weight."

Again, where are you getting this shit? That's WRONG!

I did make that bomb analogy so thank you for pointing it out. The point (which I stand by) is that an extra 2,500lbs of bombs or fuel will have a devastating effect on performance. I knwo that you and I agree on this point, just not on whether this extra 2,500lbs of fuel should be included when comparing the relative dogfighting abilities of the "D" and "N" models in a head to head match up. As I have already indicated, we are just going to have to agree to disagree. Neither of us is going to make any additional points that convinces the other. it's an argument about fairness and not reducible to an argument like if 2+2 = 4. (I have a feeling though that if your data on 2+2 came out to 4.2, you in keeping with your established pattern, would argue that it's too small of a difference to be of any consequence.)

I got my manuals over the course of many years from a bunch of sources but I understand that there is an outfit called Essco where you can ourchase flight performance and dimensional/weight data for a bunch of different aircraft. Read up and we'll talk some more.

You said, "Seems I tuckered you out; sorry. Where I work, they say I’m one of the most difficult (anal) persons to argue with, that I should have become an attorney instead of the lighting intergration department head, high profile job designer programmer for one of the largest ‘smart house’ companies out there (I have a gallery I finished in Mexico City for my company coming to the Robb Report). I do not find the attorney comment a compliment, share this with you to show that you are not alone. I am quite a handful."

A handful? The only handful you're wielding is your pecker. Look, I have the accurate stats. I have the facts. You do not. I'm not the one defending the data I have. You are the one playing defense here. That's because as between your data and mine, mine is from reliable primary sources. It's easy to argue when the facts support you. It's too bad you don't have the luxury of occupying that position here. You have no claim to facts. Yeah, you're anal all right. That's how you're so good at pulling garbage out of your ass. 

You said, "I actually hate stats."

Yeah from looking at your charts, I can see that. Obviously the product of someone who hates stats. Yep.  To be fair, it does explain why you're so mentally lazy by using your web search engine rather than seeking out prmary sources which no one can argue with. (Well, except you.) I mean, hell, as long as you can plug numbers in, who cares if they are accurate right?

Go out and get a hold of primary source accurate data Jon. You'll see that many of our differences as well as those "false memories" about fuselage lengthening will fall by the way side. This debate is over whether the "N" or "D" would be a superior contender against the F4U-4. You say "D" and I say "N". Neither of us are going to convince the other as at the heart of the debate is whether the "N" should be compared with a full internal fuel load and even you will concede that under the same fuel loads, the "N" will wax the "D" under all circumstances.

Hope you had a good Thanksgiving. I'm sure you have a chart somewhere on the proper mashed potatoes to gravy ratio that you pulled out to to argue with the family over. Lucky for you and unlike with this debate, none of your family can respond with factual data.


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## DerAdlerIstGelandet (Nov 25, 2005)

Alright lets keep this nice okay. There is no reason to get out of hand and start talking about peoples peckers. If you dont like what someone says then work it out in a friendly manner.


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## evangilder (Nov 25, 2005)

Agreed Adler. Sal, you need to tone it down some. Having a disagreement is fine, but personal attacks are uncalled for.


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## Sal Monella (Nov 25, 2005)

Agreed. I apologize Jon.

In a couple of days, I'm going to be gone for a while and won't be on the board. I probably won't be checking the board much before then either.

Good discussion!


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## Vassili Zaitzev (Nov 25, 2005)

In my opinion, Both the P47 and F4u corsair are both excellent aircraft. I think that it matters on the pilot flying it.


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## evangilder (Nov 25, 2005)

Welcome, Vassili. The pilot can make a big difference. The Finns did amazing work with the Brewster Buffalo and the Filipino pilots managed to get a couple of Zeroes with P-26 Peashooters!


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## DerAdlerIstGelandet (Nov 26, 2005)

It was not machines that won the war it was men that won the war.

Reactions: Like Like:
1 | Like List reactions


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## P38 Pilot (Nov 26, 2005)

DerAdlerIstGelandet said:


> It was not machines that won the war it was men that won the war.


Exactly Alder! If it wasnt for guys like you and everyone else who served in the armed forces, those machines wouldnt mean anything!

You could give a inexperienced pilot a really good aircraft but he could get shot down my an experienced pilot who was flying a not so good aircraft!


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## DerAdlerIstGelandet (Nov 27, 2005)

I did not work on WW2 machines....

Just kidding P38. Thanks for the compliment.


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## JonJGoldberg (Nov 27, 2005)

For all especially for Sal: You ( possibly others) appear to believe for some reason that this is a personal vendetta. It is not. I thought it simply is/was an exchange of views in whole; more importantly for me, that it had developed into an exchange that had, as one member put it, the feeling of a guy defending a thesis in front of a panel of dissecting experts. I thought to myself how wonderful (I never went to collage). I learned quite a bit from all of this, will outline some changes to the tables as a result. The outline will follow the response/s:

	Sal, your 2nd to last reply (not quoting anymore), starts with bantering about the erroneous ‘J’ data in the preceding chapters (not web sites), of an article you forwarded me a link to (at the end of which please find ‘Return to the Cradle Of Aviation Museum’; once there within a few clicks, you can view the entire article, all eight chapters). Refer people to an article, or section of an article, it is reasonable that a person would look to read the article in its entirety (‘cut paste’ policies be dammed). So what, you didn’t post this ‘J’ data… Obviously it is of no relevance to the N vs. D question, out of context; in support of the point, all of us must disseminate ‘facts’ the ‘J’ data was used. To show that even Sal disseminates ‘real’ vs ‘fiction (aka garbage)’ as evidenced by content. I made two errors: 1-I thought you would have read the preceding chapters; 2-Rather than deflecting, I thought you might actually have addressed my point.

	Your 2nd to last reply continues attempting to deflect issues. To refocus them; the amount of time your erroneous post was visible is far off issue; 10 minutes, 5 days, no difference. These points remain: 1-You make mistakes, as do I; 2-You do not admit to mistakes, rather you erase them; 3-You had made some pretty colorful remarks towards me in those deletions, you choose not to display in light of your error; all within your rights to do; all a reflection character.

	Continuing; moving to climb rates: Posted data sources with my climb figures were rebutted by your document/s of ‘unquestioned authenticity’. I defended my figure, asked that you post, E-mail, or direct me to where I might be able to see your data (only after I see your source data, will I ‘know’ I’m wrong). Have you responded in kind; no, you continue to ‘harp’ in effort to deflect that fact. Again, I may be in error, please send me or direct me to your data, please respond in kind. No response will be considered your admission that my data is correct. An accepted response will be the satisfaction of the request for accessible ‘service manual’ or ‘pilot manual’ source data, which you say you have. If the ‘service manual’ source data is received/posted, where in error, the tables will be modified. I will acknowledge my error by post the source of the correction in the tables, as done in the past.

	I thought the 2” exchange closed: You asked me to post source info, I posted it. You rebutted, asking for justification. I explained continue not to be able support my statement with any documented reference (proving not all info comes from Klingons around Ura…), in perfect cadence of our exchange; not as you suggest, by ‘sudden recollect’. I may be erroneous ( serving a vat of bull), as declared when I answered your question the 1st time. If it is found that the 2” difference is bull, or because of anything other than CG adjustment, I will, as always, admit error/s. I’ve not made the admission Sal; I’m still waiting on access to your ‘service manual’ source data, which is to include ‘D’ dimensions please.

	The Weight of radios armaments; before continuing, what follows here is an example of good that can come out of exchanges like this: Info I have says the T-Bolt carried a SCR-274N, consisting of one transmitter (type not given), one receiver (type not given) one modulator (type not given). These are the 3-radios to which I refer. You posted a listing of radio model numbers with weights, being far from versed in ‘radio’ technology as to know model numbers I looked up everything; you may confirm, follow the link address below (Sal, source info access). Now I had no idea of what I might find, is Sal on to something?... My interpretation of the data (insight into how I discern ‘fact’ from ‘vat’): The SCR-274N SCR-522 do the same exact thing, over the same frequencies. Since the 274 was of ‘Navy’ origin, I conclude it was used in the Pacific; since the SCR-522 was of British origin, I conclude it was used on the few ‘N’s that went to Europe. I conclude that they were not used together, as the ’47, in whatever version, did not have a radio operator’s station. What I find most interesting is the SCR-695, as it was/is an IFF box. Not that I don’t believe that it could have been installed in a ’47, but as if a rabbit was pulled from a magic hat, I was surprised. Hold this thought for awhile, as I’ll get back to it. Bullet Gun weights were taken from the gun table mentioned referenced on my table. Bullet Mixing: The author/s states… _Values can only be approximate, and in particular will vary depending on the particular mix of types included in an ammunition belt. The power and weight calculation takes a typical mix of ammunition, where known. They also take no account of the fact that some incendiary mixtures, and some types of HE, were more effective than others were. However, they do provide a reasonable basis for comparison. There is no point in trying to be too precise, as the random factors involved in the destructive effects were considerable._ Gun Bullet Weight: I found; referencing Table 3 (I used Table 2, like Sal am very guilty of not going through the entire document, I saw only what I wanted), whose gun bullet weights matched those on Table 2; the author/s states… _The specified weight is the weight of the bare guns and the ammunition. It does not include belt links, ammunition tanks, gun mounting points and recoil buffers, synchronization systems and trigger gear, et cetera. Realistic figures for the weight penalty would probably be 30 to 60% higher; for example, values are known of 685 kg for the P-38J and 495 kg for the P-39D._ (This is accountability Sal.) I stopped, dead in my tracks. Now, I’m going to use Sal’s numbers when available, as posted so that all may see why I stopped. From an empty weight of 10998 we add an 82 lb radio, 54 lb IFF box I had asked you to hold, 225 lb pilot, totaling 11359 lbs; to this we add 3336 lbs of fuel, totaling 14695 lbs, add to this the lighter, unadjusted weights of the guns bullets of 529 lbs 1296 lbs, your total should be 16520 lbs, above both my Sal’s ‘combat weight’ numbers. … Question; what now?

o	From the Regimental Division, Office Chief of Signal United States Army Signal Center, Fort Gordon, GA. (http://www.gordon.army.mil/ocos/Museum/ScrComponents/scrf.asp)


	Saying that I may acquire a copy of some inexactly named document/s at some site you believe to be Essco, is not in any way making your data accessible; it is not an answer in kind; it is an omission of data. You may use graphic language, snort, stomp your feet; you may tell all that I’m too ugly, short, fat, that you don’t like my hair; that you really really can’t send data until the mashed potato charts, ruthlessly enforced at the Goldberg household especially on Thanksgiving, are amended; you may tell everyone to see Chart 2... The temper-tantrum has not replaced the data. No response will be considered your admission that my data is correct. An accepted response will be the satisfaction of the request for accessible ‘service manual’ or ‘pilot manual’ source data, which you say you have. If the ‘service manual’ source data is received/posted, where in error, the tables will be modified. I will acknowledge my error by post the source of the correction in the tables, as done in the past. 

After reading this last this reply, thanks for staying with me by the way, it probably appears that I (JJG) am now conducting a vendetta. I am still defending my work, it’s accuracy by intent, anything presented in manner that any member sees as being offensive, is a mistake on my part, if pointed out will be avoided in the future.

New Table outlines, as taken from an exchange with Wmaxt 11/26/2005 7:28:10 PM Eastern Standard Time: 

I haven't posted my last response to Sal, although I read his post; from this experience, some experience now with you, as they regard to some or all of the performance data (for example the climb rate data)... I'm going to re-label the following headers, Horizontal Limits, Vertical Limits with the following: {@ Projected Combat Weight (Actual value given was calculated checked to be within the 'window' of 'reliable' specifications, when available)}. I'm going to update all 'Combat Weight' figures to read 'Calculated Combat Weight'. I will update all notes to include the amount of 'points' in question.

This should allow me to address data inconsistencies, limit mandated changes as proposed by other's measurements, documents, or other materials, to changes that I may accept, or pass, in a much less condescending light. At this point, again not to be stubborn, condescending, arrogant or rude; due to the inconsistencies of data values from the best of sources, I must both identify where I have used, continue to rely on, my own judgment.

Again, thanks for staying with me, there is a lot to read here. Maybe next weekend, with or with out Sal’s data, to better serve all I will post the new tables. PS: been working with Wmaxt in resolving, and including firing range. If we can acquire this data, this new feature should bring us that much closer.


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## JonJGoldberg (Nov 28, 2005)

Reply to all >>>

I fully agree: It, without doubt, or question was the contrabution of the men women who served that made all the differance.

That said... The topic here is: P-47N vs. F4U-4 - Which was superior? There is no flesh or bone in the question.

...Maybe I should just say "Welcome Vassili" stop looking for a fight; Sorry, signing off to cool down.

Seasons Greetings to all.


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## plan_D (Nov 28, 2005)

You had to remind me it was near christmas, didn't you? All I get when going into town is the decorations flashing in my face, and the town clock playing jingle bells on the hour. And then everyone thinks I'm weird because I don't "celebrate" christmas. 

Sorry ...carry on with your little plane talk, I'll just mutter in  ...in that corner, over there.


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## DerAdlerIstGelandet (Nov 28, 2005)

I am not sure that anyone here sees what you are doing as a vendetta, it has been interesting reading. I am just telling people to stop getting personal about it.


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## gabbys (Nov 29, 2005)

I am new to this board, so don't know if this was posted.

I did a quick scan of the thread but didn't see this posted.

This is the Curtis dive testing data for a highly modified P-47.

As to which is the better plane, it depends on where the fight is.

above 25K P-47, below 25K, I would take the F4U-4

From: http://home.att.net/~historyzone/Fisher.html



> The desire to develop a propeller that maintained its efficiency at transonic speeds led the Curtiss Propeller Division to design and test several different concepts. Herb Fisher was the logical choice to fly the test aircraft. Curtiss was able to obtain a P-47D-30-RE from the Air Corps. Fitted with one of several different “supersonic” propellers, Fisher undertook a long and risky flight test program that incorporated high Mach dives from high altitudes. Typically, Fisher would climb above 35,000 ft. He would then push over into a steep dive, allowing his airspeed to build beyond 560 mph (true airspeed). He would then execute a pullout at 18,000 ft. Several of these dives resulted in speeds of Mach .83. However, that was as fast as the P-47 could go.
> 
> Despite having a propeller that was designed to be more efficient at these speeds, the fact remained that the drag rise across the prop was so great that it functioned like a giant disk shaped air brake. Fisher had proved beyond any doubt that all previous claims of exceeding the speed of sound while diving a prop driven aircraft were untrue. There is little doubt that the pilots who reported speeds in excess of Mach 1 were honestly and accurately reporting what they has seen on their air speed indicator. However, due to the extreme rate of descent, the pressure differential in the static pressure airspeed indicator lags far behind the actual altitude of the aircraft. Air speed indicators of the era were not designed to cope with descents that could exceed 40,000 feet per minute. This difference between outside pressure and that within the system would indicate wildly ambitious speeds. These pilots had simply been fooled. When we stop and consider that the ultra-sleek P-80A Shooting Star jet fighter was never able to exceed Mach .94, how can anyone believe that a prop driven fighter could even come close?


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## syscom3 (Nov 29, 2005)

Great Find!!!!!!!!!!!!!!!


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## Gnomey (Nov 29, 2005)

Good post gabbys, welcome to the forum.


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## DerAdlerIstGelandet (Nov 29, 2005)

Welcome to the site, good post.


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## JonJGoldberg (Nov 29, 2005)

Reply to gabbys >>>

Welcome. Good post. I read the article, find it quite interesting that Curtiss was still using the '47 in 1949 as a test bed for props. That's later than I thought that they would still play with props. 

Reply to all >>>
A very interesting happened last night... Some background: I had been exchanging E-mails Wmaxt; we were discussing the P-47s ammo count on my tables, which Wmaxt felt to be high by 1/3rd. I sent him an illustration of my point, he replied saying the info I had was in error, that I should visit a web-site referred in his E-mail. I did just that will post my reply in a moment. As a side note, Wmaxt today sent me an E-mail saying that he was an enthusiast, not an expert. I'd like to say to all, I'm no expert either, I've probably have taken this a bit too far. Compulsion, my compulsion, forces this, I apologize in advance, thank you for your tolerance. Ultimately, I hope you all find his as revealing as I did...

As taken from a reply to Wmaxt: Subj: Re: WWII Gun Page 
Date: 11/29/2005 8:47:19 PM Eastern Standard Time

Thanks Bill but the site I used for my tables, that I reference, http://www.quarry.nildram.co.uk/index.htm, uses the same authors, Williams Gusting; instead of being updated in 1998, It was updated mid to end of 2004.

Now I visited your site anyway, would like to thank you as some (about 1/3 to 1/2) of the old links still worked; at the same time, I need to reconsider things: A great deal of informational links took me to the J Baugher sites, that I referenced, that you said were incorrect; further you told me you had researched this. (I did receive your E-mail about being an enthusiast) I've got to say that I've greatly appreciate all of your moral support, what I hope are 'Nobel' intentions; as opposed to others that have stated they have the books that would contain what appears below. In belief of this I share the picture (I found though your old Gun Table article; I didn't find your pic, found one on the '51, not posted) below.

Please take notice on the Ammo, Max is 3400 rounds, or 425 per gun, my stat on the D, not the N (my opinion is that this paper was drafted before the N was a thought, I believe it was written sometime around when the 47-D-11 through 47-D-23 were in production, with the 'universal' wing). Now you may interpret that I'm off by 50 rounds, but I think not. Closer inspection reveals that the 400 RPG is limit used only within the Special Combat column. What I Joe B were saying, is that when the wing was loaded at capacity, by drop tank, or bomb, each gun was limited to 267 RPG on the N, seems that there was a 200 RPG limit on the Ds. This is proven in this document (1200 rounds = 360 lbs plus 400 rounds = 120 lbs for the other two guns). The Special Combat column contains a weight addition for oil, required for extended range flights, but no specified aux tank/s, gas, or bomb, contains what is in my opinion, the 36.5 lb shackle installed on the pylons (I've no idea what the 5 lbs is for in the Max Fuel coulomb, conclude that the additional 30 lbs found in the Normal Combat column is for the 15 lb 3-tube rocket mount used at the time I believe this was written, fuel could not be applied to the pylon with this shackle, hence no additional oil). Of further interest are the gross weights in the Special Combat, Max Load column (there is a math error in the Max Load column, it should say 15100 lbs, plays a big part here). There is an 1800 lb difference between the two (actually). So the ' 47 could not carry both full ammo a full belly hard point, support at the same time wing ordinance [to 13300lbs add 540 lbs of bullets, 1333 lbs of fuel the weight of the belly tank, we are 73 pounds over weight before we add bombs, shackles).

On my tables, combat weight (D) is 13752 lbs; using this paper I should be at 13695 lbs (full internal fuel full ammo, no external ordinance), a 57 lb differance. How much does the IFF box Sal brought up Joe B confirms weigh? Its missing from the below weight table. My numbers, at lest from this hapenstance, are pretty darn close.... Too close to argue.


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## JonJGoldberg (Dec 2, 2005)

To all of my ‘P-47N vs. F4U-4’ friends >>>

No postings in such a long time; what happened? This very active thread is dead? No; its not… Let’s see if we can’t find something to talk about… 

I’d like to envision the contestants entering a 10 mile radius ‘Arena’ at a height, speed, course time designated by ‘sponsoring’ committee. After that time, until there is a victor, leaving the 20 mile cylinder is grounds for dismissal/forfeiture. The aircraft are fueled armed, as defined before, to their own individual “combat weight”, as their flight manuals dictate. The ‘sponsoring’ committee may decide to deduct proportionately from each: For example, both are to be at 50% fuel ammo from “combat weight”. The contestants should take off from the same field; at the same time, allowed 15 or 20 minutes after their simultaneous arrival; one forced to cover, at any height they feel opportunity best, 25% of the circumference of the arena traveling, as decided by coin toss, clockwise, the other counter clockwise. Upon reaching the mark, they may go anywhere, as they feel opportunity best; remaining outside the arena until the designated “combat” time, at which point they need to be inside the arena within 5 seconds; not to exit unless the victor has been decided, or choosing to be the looser.

In the above P-47N vs. F4U-4 contest I choose the N.

If the question, P-47N vs. F4U-4: Which was superior; is meant to imply, in which would you (I) choose to serve? Historically, that’s a tuff one. If service is limited to WW2, the goal is to ‘have fun’, I choose the N. If service is limited to WW2, the goal is to survive, I choose the -4.

If the question is meant to imply, which looks better I choose, today, maybe not in a few months, the 47, but my I choose a late production Razor-Back please… I promise the runner up may be an F4U-1D.

In the above I’ve chosen the ’47, 3 out of 4 times. What were your scores?


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## Jank (Dec 3, 2005)

If you read back through the thread a bit, it was generally agreed that below 30,000 feet the Corsar would take honors and above 30,000 feet the thunderbolt would come out on top.


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## JonJGoldberg (Dec 3, 2005)

Reply to Jank >>> 

...So the question remains, do I force you to my advantage or do you force me to yours?

The '47N is armed with speed, unless I let you drag me too low; no I think '47, would be able to force you high...


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## wmaxt (Dec 3, 2005)

JonJGoldberg said:


> Reply to Jank >>>
> 
> ...So the question remains, do I force you to my advantage or do you force me to yours?
> 
> The '47N is armed with speed, unless I let you drag me too low; no I think '47, would be able to force you high...



Agreed, but how can the N keep the fight above 25k, the F4U-4 vrs. P-47N dive capabilities are so close?

If the initial attack fails or is countered the fight will go lower and slower. If a N catches a Corsair above 20/25k his tactic will be to slash and climb using it's capabilities to their max (height and top speed). At altitude the turbo keeps the energy level high in the P-47 giving it the advantage.

The Corsair will dive because below 20k the N model that doesn't use the boom and zoom is going to be in real trouble very quickly. The F4U-4 can out fight it in any situation except dive and thats close enough that it isn't a clean escape for the P-47.

wmaxt


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## JonJGoldberg (Dec 3, 2005)

Reply To Wmaxt >>> 
As you dive I will pursue, not follow, from above... I will watch take my next opportunity.

Everything in the air that is beneath me, especially if it is a one-seater . . . is lost, for it cannot shoot to the rear.

— Baron Manfred von Richthofen


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## Monkeysee1 (Dec 3, 2005)

A word on critical mach.

Critical Mach is not a limiting factor for aircraft. Critical mach is the airspeed or mach number at which airflow over the wings begins going supersonic. Along with this supersonic flow, some of that air begins detaching from the wings. While this ups the amount of drag on the wing significantly it does not limit the continued acceleration of that wing or aircraft. 
What does limit an aircraft's speed is as the velocity continues to increase that area where the airflow is supersonic and thus disturbed moves back onto the control surfaces causing them to vibrate, catch, and grab (if you don't have hydraulic controls). While usually this won't make a plane uncontrollable it does make it unsteady and a handful to hang onto.
Compressability is where the sonic wave caused by the wing blocks airflow onto the elevator thus making either immovable or ineffectual as a control surface. 
Critical Mach is not a limiting factor for aircraft, the MMO (max mach operate number) is usually a few more points up on the scale. All critical mach tells you about is what point are you going to burn more fuel keeping that wing supersonic, and an idea of how 'fast' a wing do you have. It isn't limiting though.


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## JonJGoldberg (Dec 4, 2005)

Reply to Monkeysee1 >>>
I am not a pilot, nor am I an expert... My view:

The design flight envelope is not the cruise-to-stall ratio nor is it the range of airspeed between minimum maximum, rather the flight envelope of an aircraft be stated as “the parameters within which an aircraft can be safely operated, with average pilot ability, at varying density altitudes, airframe states, wing loadings and atmospheric turbulence”. Airframe states refer to CG, 'nose angle', flap extensions, undercarriage fuel tank position their weights. It is a dynamic three dimensional model which has airspeed along one axis, wing loading or 'g' along the second density altitude along the third; there are separate flight envelopes for each airframe state. These parameters usually are the limiting critical airspeeds – Va, Vne, Vno, Vs1 and Vso; the certificated load limits possibly an angle of bank limitation.

Vne – never exceed speed. The IAS which should never be intentionally exceeded in a dive or other maneuver – in smooth air; usually 90% of Vd, the 'design diving speed'.

The Army Navy posted numbers differently (for that matter everyone has their own slant, that’s why I defined mine above). I recently purchased the 'pilots manuals' (scanned reprints) for the '47D, F4U-1 (I do not have nor can I find, as of yet, manuals for the N -4) within in them the AAF simply states that the dive 'recovery' speed 'limit' is 500 mph, at 12000 ft then goes on to describe individual speed, height other limits. The Navy/Marine pilot is forced to view two tables (Angle of Attack at Terminal Velocity vs. Dive Angle Angle of Attack vs. Airspeed Indicator), cross reference them for an answer, a more 'exact' answer to be sure, but time consuming. Realizing this, compounding it with 'British' specs, German specs, I converted these numbers to a 'universally’ understood accepted, identification method for the various airspeeds at which an aircraft may be operated.

I calculated Vne ('Clean' at posted 'Combat Weight') to be 443 mph for the Corsair -4. (1st pass extrapolations from the F4U-1 book's charts put this number at 426.2 mph, but this seems way low to me, my original number seems low... anyway). 

Know and use all the capabilities in your airplane. If you don't, sooner or later, some guy who does use them all will kick your ass.
—Dave 'Preacher' Pace, USN

I calculated Vne ('Clean' at posted 'Combat Weight') to be 505 mph for the Super-Bolt. (1st pass extrapolations from the '47D book's put this number at 500 mph).

Beware the lessons of a fighter pilot who would rather fly a slide rule than kick your ass!
—Commander Ron 'Mugs' McKeown, USN

My Corsair foe might have had a cruel surprise had you not forced my exposure.


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## syscom3 (Dec 4, 2005)

John, didnt the Thunderbolt have some excellent roll effects from the torque effect of that powerfull engine and huge prop?


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## DerAdlerIstGelandet (Dec 4, 2005)

Wow you really get into this, I have to say. Good postings though Jon. I may not respong much in this thread, but I enjoy reading it.


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## pbfoot (Dec 4, 2005)

i really don't think you taken into consideration the variables that affect an a/c such as humidity, temperature etc each a/c will respond to differently to these variables plus the numbers you quote are also affected as to the state of the a/c all those max speeds you name depend on fit and finish of a/c from the factory when they achieve max speeds the a/c will have all rough edges smoothed rivets etc plus some poor guy will be waxing it down it rarely happens in real life even the amount of paint is a variable an example of that being a painted 747 can carry 10 fewer pax or equivalent fuel as a unpainted one i think it would be a rare day when any unit a/c can achieve its max speed as stated in manuals back before modern technology every a/c was different some flew higher some were slower then others of same type


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## FLYBOYJ (Dec 4, 2005)

Great stuff JJ! Some of the infomation mentioned is actually shown on modern airspeed indicators, i threw this in here just for ref......

The green should actually be normal operating speeds



pbfoot said:


> i really don't think you taken into consideration the variables that affect an a/c such as humidity, temperature etc each a/c will respond to differently to these variables plus the numbers you quote are also affected as to the state of the a/c all those max speeds you name depend on fit and finish of a/c from the factory when they achieve max speeds the a/c will have all rough edges smoothed rivets etc plus some poor guy will be waxing it down it rarely happens in real life even the amount of paint is a variable an example of that being a painted 747 can carry 10 fewer pax or equivalent fuel as a unpainted one i think it would be a rare day when any unit a/c can achieve its max speed as stated in manuals back before modern technology every a/c was different some flew higher some were slower then others of same type



The air temp, humidity etc is know as "Density Altitude" and is usually calculated in a chart within the POH. Everything else you mention is true and can even go the other way....


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## DerAdlerIstGelandet (Dec 4, 2005)

That is true, FBJ. I know that before we go and fly, we calculate our performance based off of performance charts that include weather, temp, pressure altitude and other variables. This all helps plan our time to target and what we must do in emergencies such as engine failures and stuff like that.


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## JonJGoldberg (Dec 5, 2005)

Reply to Syscom3 >>>
You guys seem always able to ask questions that require thought, however simple on the surface they appear. My answer to the torque effect question is complicated, for the most part is true only for single engine aircraft, would include the -4 as well.

Both the T-bolt Corsair’s flight manuals, confirmed by their accompanying ‘flight movies’ (both available at www.zenoswarbirdvideos.com; all materials seem deletion edited; editorial additions seem limited to company logos, opening credits) present a very simplified, ‘official’ answer: No applying power changes, other than ‘gentle’ subtraction, while diving, rolling not withstanding. Further, the training movies strongly ‘imply’ Half Roll training be preformed in the direction of torque, only one turn (interesting trivia for those ’38 enthusiasts) at high altitude, with the power OFF (meaning only enough to prevent your prop from acting as a brake). I believe this strongly suggests, as I’m not a pilot, the seriousness of two factors, torque airframe limits. Not much beyond what was mentioned above is offered in the manuals with regard to torque; there are some further ‘clarifications’ in explanation of related trim/prop/engine speed settings, but beyond repetitive ‘gentle’ reminders of respect, imbedded within ‘flight envelope’ warnings, such as during take-offs, or stalls, they do no go.

What is added now, are my opinions, for single engine aircraft, based on my much modified CFS-2 game its math (flight dynamics) engine, now about 2 ½ generations behind the ‘best’ games flight engines.

1stly > In an aircraft not modified to perform within the CFS-2 limitations of representing reality, I can do anything. In these modified aircraft I construct I can not, especially when combined with my ‘environments’, containing weather density altitude variables.

2ndly > The CFS-2 flight dynamics engine is not, with regards to torque effects, very accurate. So far I can not make it completely accurate (math wise); I can not model, nor have I ever seen (flown) a CFS-2 or MS-FS2000 flight model that can correctly represent a ’38 on take off, every model pulls one or the other way, slightly, there can be no parity/symmetry; the torque effect must be ‘happening’ within the game (this has been finally eliminated in MS-FS2K4, but to start again from scratch, in a game that does not support ‘combat’ is no fun. I await CFS-4).

3rdly > Torque effects are normally (greatly) offset by trim settings implemented during preflight cruise flying. These compensations are evidenced by drag, with dividends including reduced speed, reduced range, increased pilot stress. Once in combat, your trim settings are yet another factor in the equation, by circumstance just as easily representing no correction, as partial correction, or over correction, changing as quickly or remaining as affixed as time, damage or physics allow. Hopefully at least we have as fighter pilots (make believe, or real) acquired the ability to trim the dam aircraft correctly, to compensate for the effects of torque during preflight, the flying time before combat. Anyway, as of today, my sim (make-believe) pilot’s opinion is that in most single engine aircraft torque effect is usually best not happening, as it is very difficult to control; you can not retard power during a climb, usually needing all the power she’s got to climb; you can not up power in a dive, as gentle reduction of power during a dive to idle is required to stay below Vne keep the engine from over-revving, nor can you usually ‘trim’ your controls in combat... But the effects of torque are always in fact ‘happening’ while flying (explaining both the ‘short cut’ taken in implementing the torque effects in CFS-2, described well above, , although rarely actually put to combat, contra-rotational prop experimentation by all in the real world).

OK now… On my modified aircraft, its taken a few years (starting with less accurate, moving to more accurate as time passed, flight models) to be able to fly either a ’47 or ‘F4U (high relative mass wing loading) in a sustained powered diving roll needed to induce significant controlled torque effects, in combat, with out causing structural damage, game forced ‘over/under ‘g’ blackout during recovery, engine damage due to ‘over rev’, or more than 10 sec. of inverted flight, or of more dramatic impact, running out of room/control hitting the ground at 550 mph plus. It’s taken some more time, about an additional year or so, to learn how to use this skill, acquired through repetitive reset commands new airframes appearing at command saving my butt, far away from the ‘features’ available in reality (in other words, acquired through cheating), to an advantage so that I may destroy my sim-enemy, without cheating. I still can not perform them in any ‘weather’. The air must be relatively free of added turbulence, IE standard, in box modeled combat missions, containing no turbulence, what so ever (not even those caused by your victim directly in front of you; OK, the CFS-2 flight engine can not reproduce turbulence from your adversary, nor can MS2K4, super computer territory for now) are best for this maneuver; factious dynamic ‘missions’ where I author in density altitudes, weather (to the limits of CFS-2), are more challenging; rolls are never to be held for more than one roll rotation, extending beyond half roll rotation, except in ‘emergency’ is not reasonable as you are acquiring speed as fast as gravity, momentum, streamlining can propel you without adding power. A 25 mph gust against your recovery angle, adding to your roll speed, quickly varying your nose dive angles, deflecting your bank angles, as you approach Vne, now there is bound to be some parachuting happening, once you recover from ‘g’ black out, if you haven’t dug a hole, or been killed by your adversary as you pass uncontrollably by offering a wonderful target opportunity. Now you might think you can throw just about everything said directly above, in the trash if we were to be talking about, say a Zero. This aircraft does not accelerate or roll well in a dive, it is of low mass, low wing loading, reasonably, in fact making it far more buoyant, if you would, than either the F4U, or ’47. Torque effects may be applied (no films or manuals here, so this is not to say it was/is recommended, or ‘officially approved’) more easily, but due to narrower flight envelopes, would you? Yep, a skilled pilot during an emergency effectively will, as for the other pilots, there’s many a WW2 story about the Zeros wings crumpling while trying to remain on the tail of an American fighter, lots of gun camera footage showing what happens to them in a rolling power dive, as the plane looses controllability. The extremely effective use of power restraint during a dive, enabling combined with relatively high roll rate at speed a higher Vne, further exploited by the wingman tactic as devised by the AVG allowed many a P-40 pilot, to flame, or escape from their Japanese adversaries, fighter bomber alike.

A screen shot of the P-47D’s Half Roll Dive Chart is attached. The cut-off altitude numbers are to be found this way on my copy of this film.

As for rolling climbs, this is another matter, one where torque effects are more easily seen, can rarely be exploited by WW2 aircraft, are more often paid for. You usually need all the power she’s got to climb in the 1st place, so you’re usually running close to, at, or beyond full throttle. Roll speed, bank angles seriously affect climb rates, enough to turn a climb into a dive using a half roll. This is/was done all the time, as by WW2, airframes engines were formidable enough to ‘tolerate’ these stresses. Using two engines (which my flight sticks throttle can not faithfully reproduce, having only one throttle control) torque may be used, in this envelope to serious advantage. However, this requires of the pilot great skill familiarity with their mount.

So syscom3, to wrap up, the T-bolt could have seriously ‘excellent’ roll effects from the powerful engine prop. They are rarely wanted, probably contribute to the ‘47’s achievements; at the time (WW2) the ’47 had one of shortest life expectancies (not due solely to combat losses, but those losses are included), some of the highest training accidental loss rates (http://www.taphilo.com/history/WWII/Loss-Figures-Aircraft-USA-Training.shtml). These honors are duly offset by the fact that most of its Aces survived the war.

Reply to pbfoot >>>
FBJ answered well for me. Thanks FBJ. I’d like to apologize for not defining the term density altitude contained in my reply to Monkeysee1. I’d also like to add to FBJ’s comments on the effects of paint rivets finish. I find your arguments, for the most part, very valid. As to why they are not considered, I would answer you this way: To be able to accurately model ‘Aircraft X’ into a single representative I can embody the measured flight characteristics of a ‘number’ of known examples ‘Aircraft X’ into a single representative model. This to you would be accurate, but I’d argue the degree of accuracy depends on the skill of the pilot, the number of samples, their condition vs. the stats, the number produced thier delivered condition. Rather I feel the numbers that would best represent ‘Aircraft X’, offer the least variance would be one developed from the specifications that represent the ‘goal’ of production. After we agree that this model indeed accurately represents ‘Aircraft X’, we may from here reproduce the flight characteristics of any uniquely aged, finished, painted, assembled, or cared for example of ‘Aircraft X’ you or I desire. This discussion is, how ever valid your point, not centered on any single example, rather it is centered on the single representative of Aircraft X.

Reply to DerAdlerIstGelandet >>>
Thanks for the compliments, affirmations.


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## lesofprimus (Dec 5, 2005)

God how I hate that blue font....

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## syscom3 (Dec 5, 2005)

Jon, thanks for the info.

Reason I asked is I thought I remembered seeing some of those WW2 drawings used for training aids, that mentioned "rolling" into the direction of the prop in a shallow dive. According to the prints, it would allow a Jug to get on the tail of a more maneuverable opponent.


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## DerAdlerIstGelandet (Dec 5, 2005)

lesofprimus said:


> God how I hate that blue font....



I agree.

Also please tell me all of this is not based off of CFS-2 experiences.


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## JonJGoldberg (Dec 6, 2005)

Reply to all >>>
OK No more blue font.

Reply to DerAdlerIstGelandet >>>
If you are referring the chart, due to Zeno’s logo appearing, marketing, please be assured, they are not from, nor altered for a simulator, they are from the 1943 Republic/AAF film, available through Zeno’s flight shop (www.zenoswarbirdviedos.com). Oh, if this is the case, please disregard the below. If the above has nothing to do with what you were asking, please continue… 

I answered Syscom3 with information based on my review of the pilot’s manual training films. I then offered an opinion based on experience, qualifying the experience as a highly modified CFS-2 game experience before the rendering.

By doing this, I’ve somehow managed to ‘lower the value’ of all I’ve posted? How? I’ve only been forthcoming with regard to the source/s of any of my data or calculations, the methods I’ve used to assimilate them, to a crowd whose scrutiny is aided by an attendance of ‘real’ pilots. I produced a fighter comparison table with this data; as I’ve applied tweaks to my installation of CFS-2 with this data.

As for my opinions, unless stated otherwise, such as the CFS-2 qualification before rendering my opinion on torque effects, they are usually based on, supported by info data acquired outside CFS-2, again offered to a crowd whose scrutiny is aided by an attendance of ‘real’ pilots, regardless of my basis.

DerAdlerIstGelandet, it’s OK with me that you do not agree on this, as it is CFS-2 generated, even if it’s my CFS-2, so it’s junk to you; OK. Just don’t associate everything else I’ve posted with a single opinion clearly distinguished as being junk before it was conveyed.

Reply to Syscom3 >>>
I did not see this in the films of this training set, but I imagine this to be more successful used in a shallow climb than a dive.


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## DerAdlerIstGelandet (Dec 6, 2005)

LOL oh boy.


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## gabbys (Dec 6, 2005)

From: http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf

-4 top speed about 446 max rate of climb (WEP) about 4500.


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## FLYBOYJ (Dec 6, 2005)

syscom3 said:


> Jon, thanks for the info.
> 
> Reason I asked is I thought I remembered seeing some of those WW2 drawings used for training aids, that mentioned "rolling" into the direction of the prop in a shallow dive. According to the prints, it would allow a Jug to get on the tail of a more maneuverable opponent.



That's becuase you're using P factor to you're advantage..


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## Jank (Dec 6, 2005)

I wonder if that f4u-4 table is after wwII. It lists the military and war emergency horsepower at 2,800. I know the f4u-4 didn't have as high of horsepower as the P-47N. Something is fishy.

accepting the table though, At 26,000 feet and War emergency power, she's only pulling 2,080 horsepower though and the P-47N can pull 2,800 horsepower at 32,000 feet. There's a big power disavantage to the F4u-4 when up high.


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## gabbys (Dec 6, 2005)

Jank said:


> I wonder if that f4u-4 table is after wwII. It lists the military and war emergency horsepower at 2,800. I know the f4u-4 didn't have as high of horsepower as the P-47N. Something is fishy.
> 
> accepting the table though, At 26,000 feet and War emergency power, she's only pulling 2,080 horsepower though and the P-47N can pull 2,800 horsepower at 32,000 feet. There's a big power disavantage to the F4u-4 when up high.



That table is a little hard to read, I think that what you are looking at is RPM.

BHP at sea level using WEP was 2450

The advantage of the P-47 Turbocharger was the ability to maintain BHP from sea level to its ceiling.


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## FLYBOYJ (Dec 7, 2005)

A question to all

Are these charts from the POH?


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## Gemhorse (Dec 7, 2005)

The bottom line seems that while the P.47 was a terrific aircraft, it was the Corsair that continued on in service for years afterwards.......


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## CurzonDax (Dec 7, 2005)

The thing about the 'Bolt is that by the end of WWII it would have been obsolete to fight after WWII for the design was at the limit of its technological evolution where as the Corsair had much to improve on it. The latter versions of the Corsair had almost nothing in common with thier WWII parents.

Also the corsair was not built as a high altitude fighter for the fighting it was involved did not call for it.

On top of that supposedly a Corsair shot down a Mig in Korea!


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## FLYBOYJ (Dec 7, 2005)

"On 9 September 1952 a MiG-15 made the mistake of getting into a turning contest with a Corsair piloted by Captain Jesse G. Folmar, with Folmar shooting the MiG down with his four 20 millimeter cannon. The MiG's wingmates quickly had their revenge, shooting down Folmar, though he bailed out and was quickly rescued with little injury."

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## Jank (Dec 7, 2005)

The Thunderbolt wasn't obsolete as a design. It went on to evolve into the XP-47J and XP-72 that performed at the very edge of propeler driven capability (aproximatekty 500mph top speed).

By the end of the war, all prop fighters were obsolet - even the Corsair. It only lived on because it was carrier capable.

The shooting star could outperform any prop fighter and soon afterwards there was the Cougar (Navy) and sabre (Air Force).


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## CurzonDax (Dec 7, 2005)

True, but these versions of the 'Bolt were nothing but rehashed '30s tech. I know the Corsair was '40s tech but like you said the Corsair was more versatile because of its carrier capabilities. Also the P-47 in the post-war economy was either withdrawn, sold to foriegn countries or sent to NG units until they could get P-51s. 

But I disagree as far as being obsolete. Prop jobs could get into places, especially in the air support role that jets could not. Looks at the Corsair during the Chosin Resivoir retreat or the Skyraider in both Korea and 'Nam. While the fast movers were great, low and slow sometimes is better. Look at the A-10.

:{)


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## Jank (Dec 7, 2005)

XP-72 and XP-47J were rehashed 30's tech? Not sure I understand. The Corsair was developed in response to a Navy sped request in 1938. The first plane flew in 1940. The Thunderbolt was developed in response to a AAF spec request in 1939 and first flew in 1941.

The P-51 was a lot cheaper to churn out and a lot easier on the gas mileage.

I agree with you. I meant that prop driven planes were bsolete as fighters. Air to air was now the jurisdictyion of jets. The skyraider (close air support) is an excellent example of where prop driven planes still were best.

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## CurzonDax (Dec 7, 2005)

The P-47 was really the culmination of Seversky designs which by the war's end were really obsolete, more so than the Corsiar. Even the XP-72 and XP-47J were really offshoots of this technology with new gizmos to make them competitive in the aviation market. Republic saw the writing on the wall and tried to make thier product better for the post-war military. That is why the F-84 Thunderstreak was so important for thier survival. But I think the Flying Boxcar served them better in the longrun.

:{)


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## Jank (Dec 7, 2005)

The XP-72 and XP-47J are proof that the P-47 wasnt at the end of its design potential. You can say that any evolutionary change is an offshoot. The Thunderblt was no more obsolete than the Corsair at war's end and in fact, the thunderbolt had more design potential left as evoidenced by the XP-72 and XP-47J. 

Can you explain why you feel that at the war's end, the Thunderbolt in its M and N model configurations had less potential than the f4u-4?

The Corsair lived on due to it's carrier capability and the fact that high altitude escort duty was no longer an efficient role for prop driven planes due to teh advent of jets. At low to medium altitudes, the advantages of the Thundetbolt coiuldn't be realized.


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## CurzonDax (Dec 7, 2005)

You just answered your own question. I think we are saying the same things from the opposite sides of the street.

:{)


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## The Nerd (Dec 8, 2005)

The Jug was definitly tough, but I would go with the Corsair for its climb rate if nothing else.


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## Jank (Dec 8, 2005)

I don't think the F4u-4 would have any real advantage in climb at higher altitudes. (Agree that it would at low and medium altitudes)

The F4u-4 is only pulling 2,080hp at 26,000 feet down from 2,450 at sea level.

The Thunderbolt N is pulling 2,800hp at 32,000 feet (She pulls 2,800hp at sea level too)

By the time you're getting beyond 25,000 feet, I think the Thunderbolt is getting pretty close in climb and by the time you're at 30,000 feet, the Thunderbolt would overtake the Corsair because that's 4,000 feet over critical altitude for teh Corsair. The horsepower of the corsair is really hurting and would probably be about 1,900 or so vs. 2,800 for the T-bolt.


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## gabbys (Dec 9, 2005)

Jank said:


> I don't think the F4u-4 would have any real advantage in climb at higher altitudes. (Agree that it would at low and medium altitudes)
> 
> The F4u-4 is only pulling 2,080hp at 26,000 feet down from 2,450 at sea level.
> 
> ...




the chart i posted on page 8 has the P-47D climb rate up to 30K.

the F4U-4 still maintains a higher climb rate. Even the F4U-1 and F6F-5 maintained a very slightly better climb rate up through 30K.


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## Jank (Dec 9, 2005)

"the chart i posted on page 8 has the P-47D climb rate up to 30K. "

I noticed that. The threead is about the N model though which is not a D. My post concerns the N. The horsepower of the N is 2,800. 

Do you know which D model your chart is refering to? Different D's differ in Horsepower and type of propeler. The late war horspower of a D model was 2,530. Your chart shows the P-47D horsepower as less than the F4u-4 up to about 8,000 feet. Don't think so.

That can't be right if we're comparing apples to apples. If we are comparing a late war D model against an F4u-4 then the relative WEP horsepower difference would be 2,530 (P-47D) vs. 2,450 (F4u-4). Your chart either is not comparing a late war D model or a late war D model not at WEP.


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## Gemhorse (Dec 9, 2005)

Still, it was a shame to have discarded the 'Bolt', and the P.38 too, at the end of the War, as the Bolt's ground-attack capability was terrific....As stated, it was pushing to the edge of Prop-aircraft's ability, but perhaps the advent of the Bearcat and Tigercat coming on stream had something to do with it...I agree that the Corsair had the aircraft-carrier advantage in it's favour, although it wasn't really the 'bees-knees' of carrier aircraft.......


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## gabbys (Dec 9, 2005)

Jank said:


> "the chart i posted on page 8 has the P-47D climb rate up to 30K. "
> 
> I noticed that. The threead is about the N model though which is not a D. My post concerns the N. The horsepower of the N is 2,800.
> 
> ...




I'll try to dig it up, but here is a good write up on the p-47N

Climb at 20K is 2550, still below the U-4.

http://home.att.net/~jbaugher1/p47_13.html


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## Jank (Dec 9, 2005)

I'm sure you'r right about the f4u-4 outclimbing the N model at 20,000 feet.. That's why in my earlier post I said -

"By the time you're getting beyond 25,000 feet, I think the Thunderbolt is getting pretty close in climb and by the time you're at 30,000 feet, the Thunderbolt would overtake the Corsair because that's 4,000 feet over critical altitude for teh Corsair. The horsepower of the corsair is really hurting and would probably be about 1,900 or so vs. 2,800 for the T-bolt."

I was wrong though on teh horsepower of the Corsair atb 30,000 being about 1,900. According to your chart, at about 25,000 feet, the horsepower is more like 1,700 so at 30,000 you could just imagine.

Oh, and I think the climb rate listed for the N on that website has aklready been discredited as too low.


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## gabbys (Dec 10, 2005)

Jank said:


> I'm sure you'r right about the f4u-4 outclimbing the N model at 20,000 feet.. That's why in my earlier post I said -
> 
> "By the time you're getting beyond 25,000 feet, I think the Thunderbolt is getting pretty close in climb and by the time you're at 30,000 feet, the Thunderbolt would overtake the Corsair because that's 4,000 feet over critical altitude for teh Corsair. The horsepower of the corsair is really hurting and would probably be about 1,900 or so vs. 2,800 for the T-bolt."
> 
> ...





I agree with you 100%


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## JonJGoldberg (Dec 11, 2005)

The posting from gabbys was as informative as it is misleading.

The tests done with an F4U-4 were done using the following:

1-	The data in all comparison tables charts showing F4U-4 performances were done with a model equipped with an R-2800-C @ 70 or better in. HG. Not only was this not a standard engine (P&W R-2800-18 or -18W), but it was operated outside its ‘rated’ envelope. See posted my accompanying image 1 - F4U-4 R-2800-C RATED POWER. Notice that this table shows power well below those in the ‘comparison’ charts gabbys posted; both taken from the same article gabbys referenced.

2-	The F4U-4 power plant standard I mention is confirmed in image 2 –CHARASTICS OF CURRENT FIGHTERS, again taken from gabbys article, re-enforced every time you see “70” in gabby’s posted charts, as it ‘denotes’ a difference from the ‘referenced’ numbers, in my opinion. Continuing image 2 states that the P-47D had a 12’ 2” prop of a ‘C’ model (‘modern’ P-47D would have had a 13’ prop), that the P-51D was in fact a B.

3-	Image 3 – F4U-4 PERFORMANCE WITH P&W R-2800-18W shows, again taken from gabbys’s article, displays performance numbers well below those illustrated in the comparison charts gabby posted, cementing my points.

I hear the bells of a previous discussion, IE comparative tests P-47N vs. P-47D another member referenced.


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## Magister (Dec 12, 2005)

Great charts Mr. Goldberg.


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## CurzonDax (Dec 13, 2005)

Kickin charts. I may have missed the post but where did you dig this stuff up?

:{)


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## gabbys (Dec 13, 2005)

CurzonDax said:


> Kickin charts. I may have missed the post but where did you dig this stuff up?
> 
> :{)





See my post here

http://www.ww2aircraft.net/forum/about3233.html


some mostly other aircraft compared to F4U, great overall content.





..


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## JonJGoldberg (Dec 13, 2005)

Reply to CurzonDax >>>

I can not take any credit here, other than the interpretive comments large size of the .JPGs, as the charts were contained in a posting from gabbys, to whom you Magister owe your praise thanks.



> gabbys Posted: Tue Dec 06, 2005 7:11 am
> From: http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf



I have posted a fighter comparison chart of my own, you may find here...
http://www.ww2aircraft.net/forum/about962-0-asc-520.html
Download the PDF, found below the picture.


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## pbfoot (May 25, 2006)

For all the charts and all I see no mention made of what type of props were used were they the Curtiss Wright Electrics or Hamilton Standard I read where some of the pilots prefered the Hamilton props over the hollow type Curtiss because of less flex in the blade giving it better purchase hence better performance


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## Jank (May 26, 2006)

Some trivia:

The propeller on the P-47M and N models (according to Republic Aviation) weighed 565lbs.


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## Skyraider3D (Aug 10, 2006)

Quite some discussion!

Fact is Corsairs were still being used in Korea while Jugs weren't, which probably says enough about the aircraft's usefulness if anything else


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## syscom3 (Aug 10, 2006)

Skyraider3D said:


> Quite some discussion!
> 
> Fact is Corsairs were still being used in Korea while Jugs weren't, which probably says enough about the aircraft's usefulness if anything else



It has more to do with the fact that carrier jets still were in their infancy while the USAF was fielding its second generation jets.


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## Skyraider3D (Aug 10, 2006)

Actually, Panthers and Skyknights and later Banshees were in the thick of the action, and USAF made extensive use of the Mustang for ground attack, so that argument doesn't hold too well


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## FLYBOYJ (Aug 10, 2006)

The P-47 was not used in Korea becuase of cost. It was decided in the late 40s that the P-51 was going to be the standard recip mount of the 5th AF.

The Navy kept the Corsair on becuase there still was a mission for it. Many of the early jets in the ground support roles didn't have the legs the Corsair or Skyraider had. There was even squadrons moved to the mainland to support combat operations; during Korea most of the Navy's jets stayed on the carrier unless deployed to well-built concrete runway airfields.


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## syscom3 (Aug 10, 2006)

Skyraider3D said:


> Actually, Panthers and Skyknights and later Banshees were in the thick of the action, and USAF made extensive use of the Mustang for ground attack, so that argument doesn't hold too well



The F-51's were used because there was nothing else available early in the conflict. They were quickly replaced as F84's (and others) became available.

And for the USN, untill there were engines powerfull enough to give the carrier jets a good payload and radius of action, they were still a generation behind the USAF.


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## lesofprimus (Aug 10, 2006)

Have to agree with FBJ and syscom here.... Once there was a replacement available, the prop jobs were sent to the scrap heap or Honduras...


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## Skyraider3D (Aug 10, 2006)

Except for the mighty Skyraider of course! 


PS. The USAF held on to P-51s over P-47Ns and in mock dogfights the P-51s didn't stand a chance against the F4U-4. Speaking of Honduras, the Cavalier Mustangs were easy meat too for the Honduras F4U-5s.


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## syscom3 (Aug 10, 2006)

Skyraider3D said:


> Except for the mighty Skyraider of course!



The skyraider was not a fighter.


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## FLYBOYJ (Aug 10, 2006)

syscom3 said:


> The F-51's were used because there was nothing else available early in the conflict. They were quickly replaced as F84's (and others) became available.



True, but all other recips were withdrawn from service or sent to the reserves (P-47). It was planned to have the P-51 (F-51) remain in active and reserve reserve units prior to the start of the Korean War.



syscom3 said:


> The skyraider was not a fighter.


Attack, fighter bomber maybe?!?!?

Tell that to this guy!!!






Midway Sailor


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## Skyraider3D (Aug 10, 2006)

The Skyraider was one hell of an attack bomber though!
It could drop just about anything...
USS Midway - VA-25 Toilet Bomb


Skyraiders indeed accounted for a few MiG-17s in Vietnam. And in mock dogfights they outturned Corsairs.

Can you tell what my fave plane is? 


Anyway, back on-topic... both the P-47N and F4U-4 were great machines but I'd definitely put my money on the Corsair.
Here's some more about the F4U-4's performance:
Chance Vought F4U-4 Corsair


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## renrich (Jan 21, 2007)

The only reason the P47N had a range advantage over the F4U4 was because of the extra long wing span packed with fuel. Because of that wing span the roll rate of the N was seriously degraded and it's rate of climb was horrible. Very little ACM ever took place at 30,000 feet or better with recip. engines. In ACM the P47N would be at a serious disadvantage with the F4u-4. My uncle was an instructor in P47s during WW2 and he told me they used to fly to a gunnery range near Corpus Christi and would often be jumped by F4Us. He said it was embarrasing as they had no chance against the F4Us. I don't what models they were.


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## renrich (Jan 21, 2007)

Regarding the dive performance of the P47D: the dive limit speed was 500 mph IAS,(above 25000 ft it was 400mph) recovery was recommended at no lower than 12000 ft. At that altitude the limit dive speed corresponded to 601TAS .82 mach


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## renrich (Jan 21, 2007)

At military power, the P47N had a rate of climb of 1700 fpm up to 20000 ft. At 30000 ft with military power it's top speed was slightly less than 420 mph TAS. At 26000 ft it was quite a bit slower than the F4U-4.


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## renrich (Jan 21, 2007)

Don't know where the performance figures for the P47N are coming from but they don't jibe with the figures in AMERICAS HUNDRED THOUSAND by Francis DEAN.


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## renrich (Jan 22, 2007)

The fact is all this talk about performance at 30000 feet or above is rather theoretical because very little ACM took place above 25000 ft in ww2. The fact is the B17s and B24s the Jugs, Mustangs and Corsairs escorted when loaded could barely get to 20000 feet. However a F4U-4 intercepted a nip reco. plane at 38000 feet above Okinawa. When he found his guns were frozen he sawed off the Jap's empennage with his prop.


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## syscom3 (Jan 22, 2007)

renrich said:


> ..... The fact is the B17s and B24s the Jugs, Mustangs and Corsairs escorted when loaded could barely get to 20000 feet.



The B17's routinely flew at 30,000 feet.

P38's and P47's were designed from the outset to fly at that altitude.


I dont know where you came up with that 20,000 figure.


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## Jank (Jan 23, 2007)

Indeed. And B-29's flew at 30,000ft as well. Thus, an escorting fighter must be able to perform at those high elevations.

The P-47N is pulling 2,800hp @ WEP up to 32,000ft. 

At Military Power, the P-47N can pull 2,100hp all the way up to 35,000ft!

At Military Power, the F4U-4 can pull 1,800hp up to 23,000ft. It simply was not designed for high altitude escort work.

Now, yes, with a full load of internal fuel, 570 gallons, the P-47N is indeed hampered vs. the 234 gallon internal fuel load of the F4U-4. What do you expect? 

The P-47N had fuel cells in the wing and not conventional tanks. They dodn't have to be used. That means she could still carry 370 gallons in the internal tanks without the wing tanks.

In that configuration, her performance would have been much closer to an "M" than a "D."


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## renrich (Jan 23, 2007)

That is the trouble with all this academic talk. The B17E had a service ceiling of 36600 ft but that did not mean it bombed from that altitude. I recently read a book by the lead navigator of the 100th bomb Group and they routinely bombed from 18000 feet. I know or knew a couple of B24 pilots and with a full load of ammo,fuel, and bombs they were doing good to get to 20000 ft. The F4U-4 had a service ceiling of over 41000 feet but they almost never operated at anything near that altitude. Yes, the B29s could and did bomb from 30000 or more but couldn't hit anything because of the winds aloft so had to bomb from much lower. The P51, the primary escort fighter of the B29s(and the bombers in Europe) was severely hampered at altitudes of 30000 or more because of it's supercharger. The F4U-4 achieved it's max speed of 445 mph at 26000 ft at 30000 it could "only" do about 435 mph. The N model Jug was 5 to 10 mph slower than the D becuse of it's increased weight. Little ACM was conducted at top speeds anyway. That is the reason that the KI84 that was not a true 400 mph fighter was quite effective against all our fighters.


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## Jank (Jan 23, 2007)

"The N model Jug was 5 to 10 mph slower than the D becuse of it's increased weight."

Not true.
USAAF Test Data


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## JoeB (Jan 23, 2007)

renrich said:


> 1. The B17E had a service ceiling of 36600 ft but that did not mean it bombed from that altitude. I recently read a book by the lead navigator of the 100th bomb Group and they routinely bombed from 18000 feet. I know or knew a couple of B24 pilots and with a full load of ammo,fuel, and bombs they were doing good to get to 20000 ft. The F4U-4 had a service ceiling of over 41000 feet but they almost never operated at anything near that altitude. Yes, the B29s could and did bomb from 30000 or more but couldn't hit anything because of the winds aloft so had to bomb from much lower.
> 
> 2. That is the reason that the KI84 that was not a true 400 mph fighter was quite effective against all our fighters.


1. B-17's in the ETO typically bombed from the low-mid 20's k ft. 18 would have been unusual though not unheard of, maybe you should cite the exact source. B-17's typically bombed from a bit higher than B-24's where low 20's would be more typical. The big difference there was vulnerability to AAA, considerably less at the higher range of typical altitudes, so 18k against heavily defended Reich targets doesn't sound right. The 8.8cm Flak 36/37, backbone of the German AAA right to end, had an effective ceiling around 26k, so the B-17's ability to get close to that practically, while maintaining sufficient course stability to bomb reasonably accurately in big formations (that's what limited B-24 altitudes) was one reason for the 8th AF's preference for the B-17.

However early in the war, in the Pacific, B-17's did in fact bomb from as high as 30k, small formations of unescorted bombers trying to avoid interception by JNAF fighters (see "Fortress Against the Sun" by Salecker for a number of examples).

The initial unescorted B-29 raids over Japan were from high 20's to just over 30. Then night raids starting March '45 much lower (low teens or even less); then escorted day raids starting in April were similar to ETO, low-mid 20's.

However, escort fighters are better off to be able to cover their bombers from above, altitude advantage is always desirable, and if the battle centers on bombers at 25k ft (as opposed to say torpedo planes at ~zero ft), the ability to bounce from ~30k is very useful. See Robert S Johnson's account in "Thunderbolt" of German fighters occasionally trying to sneak in on escorted formations from around 40k ft.

2. The practical speed of operational Ki-84's is still debated, but "quite effective" would be have to be based on Japanese claims repeated in Western books (kind of the inverse of the typical situation of underrating the earlier Japanese types based on continuously repeated inflated *Allied* claims). The real situation is somewhat fuzzier. Naturally with a big performance advantage the Ki-84 almost had to do better, but even the late Japanese types were pretty clearly on the short end of exchange ratio stick v. US fighters in the actual overall situation of 1945. Breaking out figures, accurately, by type is hard (they exist on the US side in some cases, but the radial Japanese fighter types were frequently mistaken for one another, esp late in the war with such a long menu to choose from, as is easily seen for the combats that can be identified in Japanese records).

Back to P-47N v. F4U-4: it reminds me of late mark Spit v P-51. Comparing in a vacuum is one thing, but the P-47N had the range for missions an F4U just couldn't perform, any plane is worth zero in the areas it can't reach. For example speaking of the P-47 over Korea it did operate there, at the end of WWII! The Marine Corsairs based in the Okinawa/Ie Shima airfields couldn't reach Korea, P-47N's could and flew missions there in the last week of the war, with good success against the JAAF Ki-84's based there. It's a moot point whether a Corsair could have done better.

Joe


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## the lancaster kicks ass (Jan 23, 2007)

i don't agree with your last point, because using that logic the B-17's a better fighter than the spitfire because it could fly further? there are so many other factors, range is just one small one...........


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## JoeB (Jan 23, 2007)

the lancaster kicks ass said:


> i don't agree with your last point, because using that logic the B-17's a better fighter than the spitfire because it could fly further? there are so many other factors, range is just one small one...........


Seems a kind of ridiculous stretching of the logic to compare heavy bombers and fighters. Range was not one small factor for a fighter but one large factor in offensive use of air power as a whole in many situations in WWII. Long range fighters could increase the effective reach of bombers (not just level ones against land targets but for sea control), and increase the size of steps amphibious forces could take advancing across a theater. The exact degree depended on geography but in the Pacific War a short legged fighter was of limited use almost regardless of its performance otherwise.

That worked both ways; the Japanese could never have achieved their conquests of the early months of the Pacific War without landbased A6M's (and Ki-43 to a lesser degree) extraordinary range. And it was true when the shoe was on the other foot later in the war. But it was true as well in cases in Europe, like how far the Allies could advance at a step in invading Sicily and Italy (had mostly short legged fighters, so not very far), and in the Greek islands in late 1943, even aside from the day/night strategic bomber debate.

In offensive landbased air ops in large theaters, range was the *main* comparative factor in evaluating the true usefulness of fighters. *If* the fighter met a minimum standard of reasonable competitiveness with the defending fighters it would meet. Besides a silly example like B-17 a realistic one would be Ju-88C long range day fighter: not minimally competitive with Allied single engine fighters of 1943-44 (though OK hunting Allied ASW planes over Bay of Biscay), so not a superior offensive fighter compared to short legged singles. But the P-51 v the Germans in 1944 did meet that hurdle; so did the P-47N in the Pacific in 1945 (and P-38 thru the Pac War); they could deal quite well with defending enemy fighters. Given that minimum relative air combat performance, the whole planning of air and amphibious operations was based on the range of landbased fighter cover (where carriers weren't available), the more the better and without practical limit in the Pacific. Very non-small factor. Fighters with half the range essentially required twice as many sea-air-land battles to be fought to get to the same place.

Switch to a strategically defensive situation, and range decreases as a factor. But it still gives the advantage of combat persistence (eg. German fighters which still often had to break off first for lack of fuel against P-51's *over Germany*) and ability to concentrate forces in the air (eg. Japanese fighter units in SEA in 41-42 were not numerically superior overall, quite inferior counting A6M's alone, but consistently defeated the Allied fighters in part by concentrating superior numbers at each give point of attack; the defending Allied fighters were short legged so had be spread out over the large theater). Fighter range/endurance was never (and still isn't) a small factor to be artificially ranked the same as climb or roll rate. It's an important category to be considered separately from air combat performance, it can be a dominant factor in offensive use of air/sea power.

Joe


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## merlin (Jan 23, 2007)

I seem to remember that if the RAF couldn't solve the problems they had with the Typhon, they were going to go for P-47's!
What does everybody think, if they had given up on the Typhon, would the RAF been better off having the Thunderbolt, or the Corsair??


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## the lancaster kicks ass (Jan 23, 2007)

Typhoon any day, far better suited our needs and there was actually some 20mm ammo in Britain at the time  plus of course the family she gave birth to............


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## lesofprimus (Jan 23, 2007)

JoeB, the range factor is not as important as u are letting on... While it is important, when ranking aircraft ie. Best at This ect ect, it is factored in as a minor statistic....

Everyone pretty much agrees with this....


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## Jank (Jan 23, 2007)

The "range factor" is what makes one aircraft suitable for long range escort role and another not suitable. This change in role comes at the expense of tremendous extra weight and degradation of performace. 

Perhaps a better comparison would be the P-47M and F4U-4.


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## Jank (Jan 23, 2007)

*5.4 minutes to 20,000 feet.*


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## renrich (Jan 25, 2007)

The US would have been better served overall if, in 1940, they had contracted with Republic under license to build the Corsair in a strictly land based version and cancelled the P47 program. Of course, in those days it was unheard of to expect a shipboard fighter to compete with a fighter that was designed to be land based.


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## renrich (Jan 25, 2007)

Pardon me, please. I misspoke about the bombing altitudes of the B17. My data came from the book A WING AND A PRAYER. The 100th bombed from 18000 ft during the Schweinfurt raid because of an overcast they had to get under. They routinely bombed from 24000 to 26000 ft but never mentioned bombing from 30000. I believe that the cold temperatures over Europe made it very difficult to operate at anything like the service ceiling of the aircraft. It was mentioned that often the radio gunner and waist gunners often suffered frostbite to the extent they were hospitalized. I still maintain that little ACM occurred at altitudes of 30000 or above.


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## Jank (Jan 25, 2007)

"The US would have been better served overall if, in 1940, they had contracted with Republic under license to build the Corsair in a strictly land based version and cancelled the P47 program." 

If they had modified it to carry more internal fuel so that it would have the same range as the Thunderbolt and then modified it further to give it high altitude performance, perhaps it would have been cheaper to churn Corsairs out.

Didn't the earlier corsairs have lots of teething problems? I don't recall now.

It should be added that towards the end of the war, the F4U-1 didn't have any appreciable performance advantage over the P-47D with water injection and paddle props. (See thye thread on this subject)

Early in the war though, the P-47 was a dog. Toothpick props gave it a lousy climb rate on the order of 2,750fpm @ SL.


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## davparlr (Jan 25, 2007)

syscom3 said:


> The F-51's were used because there was nothing else available early in the conflict. They were quickly replaced as F84's (and others) became available.
> 
> And for the USN, untill there were engines powerfull enough to give the carrier jets a good payload and radius of action, they were still a generation behind the USAF.



I agree with this. The Panther, Banshee, and Skynight (a slow nightfighter that doesn't belong here) were all in the same class as the F-80, and therefore obsoleted by the F-86/Mig 15, which the Navy had no answer for for until after the Korean War.

Basically the F-47 was not selected as a primary aircraft because of buget cuts and the favortism (right or wrong) for the F-51, only one of which could be afforded. The Navy had limited options.


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## YakFlyer (Jan 26, 2007)

It must have been the F4U.


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## syscom3 (Jan 26, 2007)

In 1940, the P47 or the F4U were strictly experimental. Noone could predict which one would excell in what role.


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## JoeB (Jan 26, 2007)

lesofprimus said:


> JoeB, the range factor is not as important as u are letting on... While it is important, when ranking aircraft ie. Best at This ect ect, it is factored in as a minor statistic....
> 
> Everyone pretty much agrees with this....


It's often treated as a minor statistic in basically unrealistic discussions of fighter planes, abstracted from the reality of air power as a tool of war. It doesn't make it correct, and far from "everybody" agrees. The reality remains a long range fighter could have a strategice level influence on what basic campaign plans, sea air and land, were feasible and which were not. It could hardly be more important on the air/sea offensive in large theaters.

Then way down at the air combat tactical level, we just have to consider, could the inevitably heavier (US case, or less rugged or less well protected Japanese case), long range fighter deal reasonably well with defending enemy fighters? Climb, turn etc were among the factors determining that, but even at that level stuff like pilot quality, tactics, maintenance, fuel quality were usually more important; again given same ballpark of paper air combat performance.

Paper air combat performance (as in small speed, climb etc differences) is what's *WAY, WAY* overrated, again if trying to understand air war history, a/c not some technical discussion for its own sake. IMHO.

Re: F-51 in Korea it wasn't "politics" but expediency given the FEAF's familiarity, spare parts supply and even small number, 47, of F-51's still on hand in the FEAF in Japan though not in operational units; plus larger number of active F-51's (active here means not in storage) on the US West Coast.
From an original USAF document the inventory of F-47's and F-51's June 30 1950 was as follows:
USAF: F-51's active: 99, inactive: 798, total: 897
F-47's active: 79, inactive: 771, total: 850

Air National Guard: F-51's active: 907, inactive: 0, total 907
F-47's active: 498, inactive: 1, total: 499

Total F-51's active: 1006, inactive: 798 , total: 1,804
F-47's active:577, inactive: 772 , total: 1,349

The F-51 was not rapidly replaced in Korea. Some to all sdns of the FEAF's 8th, 18th and 39th FG's converted from F-80C's back to F-51D's in summer '50 after the war broke out. The 8th went back to all F-80 after the MiG threat emerged from late '50, 39th did leave the theater in '51 corresponding to F-84 build up, but the 18th flew F-51's till the end of 1952 when it converted to F-86F's.

Joe


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## renrich (Jan 26, 2007)

Vought received a Navy request for a production aircraft proposal in Nov. !940. I believe they were convinced they had a winner then. The early P47 had only a 900 mile yardstick range on internal fuel whereas the first production F4Us had a yardstick range of 1500 miles on internal fuel. Given the superior performance of the Corsair in almost every category, if Republic had been obliged to manufacture an AAF version of the F4U there would have been a longer ranged escort fighter available earlier in the war. Imagine what kind of performance an AAF version of the F4U would have had when Republic deleted the folding wings, the tail hook and other extraneous shipboard requirements which added weight to the Corsair. Possibly the AAF version could have been turbocharged. Vought experimented with turbocharging the Navy Corsair. The Corsair did have a number of teething problems that were primarily a problem in executing carrier landings. They would not have precluded it from operating with the AAF. Not withstanding those problems the F4U got into action several months before the P47.


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## syscom3 (Jan 26, 2007)

The P47's (B Model) were in combat by Oct 1942, a full 1/2 year before the Corsair. Plus while the P47 had its share of teething problems in its prototype stage, it never had the problem the F4U had with green pilots.

I also haven't seen any references for the F4U-1 fuel figures of 1500 miles. 

In 1941, no one could have predicted which plane would have been better because one was designed for carrier ops, the other for land based operations at high altitude.

It wasnt untill towards the end of the war when the latest models of the Corsair started to perform better than the P47's. But by then, the P47 was flying ground attack missions and its superior firepower made it better in that role than the Corsair.

The P47 even has song about it. The F4U doesnt.

Johnny Come Lately
by Steve Earle

I'm an American, boys, and I've come a long way
I was born and bred in the USA
So listen up close, I've get something to say
Boys, I'm buying this round
Well it took a Iittke while but we're in this fight
And we ain't going home 'til we've done what's right
We're gonna drink Camden Town dry tonight
If I have to spend my last pound
When I first got to London it was pourin' down rain
Met a Iittle girl in the field canteen
Painted her name on the nose of my plane
Six more missions I'm gene
Well I asked if I could stay and she said that I might
Then the warden came around yelling "turn out the lights"
Death rainin' out of the London night
We made love 'til dawn

But when Johnny Come Lately comes marching home
With a chest full of medals and a G.l. loan
They'll be waitin' at the station down in San Antone
When Johnny comes marching home

MY P-47 is a pretty good ship
And she took a round coming cross the Channel last trip
I was thinking 'bout my baby and letting her rip
Always got me through so far
Well they can ship me all over this great big world
But I'll never find nothing like my North End girl
I'm taking her home whh me one day, sir
Soon as we win this war

Now my granddaddy sang me this song
Told me about Londen when the Blitz was on
How he married Grandma and brought her back home
A hero throughout his land
Now I'm standing on a runway in San Diego
A couple Purple Hearts and I move a little slow
There's nobody here, maybe nobody knows
About a place called Vietnam


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## Jank (Jan 26, 2007)

"I also haven't seen any references for the F4U-1 fuel figures of 1500 miles."

I have seen the 1,500 mile range figure. It is with one 150 gallon external fuel tank.
http://www.wwiiaircraftperformance.org/f4u/f4u-1d-acp.pdf

That's about 1,000lbs of fuel by the way.


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## Jank (Jan 26, 2007)

For performance charts of the late model F4U-1 and P-47D see the thread further down this forum with a title on the subject of the late war F4U-1 and P-47D.
-------------------------------------


See Section B on page 3 for a comparison of the early F4U-1 and P-47C. (I have summarized it below)
http://www.wwiiaircraftperformance.org/f4u/f4u-1-02296.pdf



The F4U-1 has a better rate of climb at 5,000ft but at 10,000ft, they are equal with the P-47 improving therafter and having the best rate of climb at 25,000ft.

The F4U-1 has better initial acceleration but the P-47C quickly catches up and passes it.

P-47C has higher speed in level flight at 22,000ft.

F4U-1 has best level flight radius of turn.

Both have equal roll rates in level flight but in a dive, at 300mph, the P-47C is better and remains better as speed increases.

F4U-1 has better initial zoom but P-47C catches up with the resulting same gain in altitude.

F4U-1 noses over more sharply from level flight at high speed but the P-47C quickly out dives the F4U-1.

The F4U-1 is better for close in fighting.

The time required for maintenance of the F4U-1 is greater than for any other Army Air Force fighter plane. A laundry list of maintenance problems and items prone to breaking is then listed from A through K. The report concludes with, "In general, the airplane is unsatisfactory for service and maintenance work."

Reactions: Informative Informative:
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## syscom3 (Jan 26, 2007)

He claimed it was on internal fuel.

Give the P47 an external tank and it's range improves quite a bit.

Also look at how the F4U-1 was superior to some aspects of the P47C but not all. If you want to fight at 30,000 ft, use the P47. If you want low and mid altitudes, use the F4U.

There really is not one thing to be gained by the AAF in 1941/42/43/44 by using the F4U.


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## Jank (Jan 26, 2007)

Some data for late war F4U-1 and P-47D:

Climb at S/L - 3,100fpm (Corsair) 3,150fpm (Thunderbolt)

Climb at 10,000ft. - 2,975fpm (Corsair) 3,050fpm (Thunderbolt)

Climb at 15,000ft. - 2,700fpm (Corsair) 2,900fpm (Thunderbolt)

Climb at 20,000ft. - 2,250fpm (Corsair) 2,650fpm (Thunderbolt)

Max Speed at S/L - 353mph (Corsair) 340 mph (Thunderbolt)

Max Speed at 20,000ft. - 405mph (Corsair) 415 mph (Thunderbolt)


The F4U-1 can pull 2,000hp as high as 19,000ft. After that it begins to steadily drop off. At 25,000ft, it's pulling 1,500hp. The P-47D could pull it's full 2,535hp well beyond 25,000ft.


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## Jank (Jan 26, 2007)

"If you want to fight at 30,000 ft, use the P47. If you want low and mid altitudes, use the F4U."

I think the F4U-1 loses it's lower altitude advantage well shy of 30,000ft. More like 20,000ft.


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## renrich (Jan 27, 2007)

The F4U1,1A and 1C carried 361 gallons of internal fuel.


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## Jank (Jan 27, 2007)

I recall that they carried about 235 gallons internally.


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## renrich (Jan 27, 2007)

I would like to see backup on P47B operations in Oct. 42. My data shows the first operational mission was on March 10, 1943. 14 P47s and 12 Spits over France. This was the 4th fighter group and some of the 4th pilots refused to fly the P47. "There are crashes, dead stick landings, mid-air fires, bailouts and gear collapses on the runway. Some pilots die in operational accidents. On this first sweep radio interference problems are encountered. Plane to plane communication is impossible." The first official operation with the 8th air force is on April 8, 1943. The Corsair's first operational mission was on Fe. 14, 1943.


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## renrich (Jan 27, 2007)

The F4U1s until the F4U1D had wing as well as fuselage tanks. My data has the pilots manual for the P47B,C,G and early Ds showing a time to climb to 20000 feet with Mil power of approx. 12 minutes. The F4U1 could do the same with Mil. power in approx. 9 min.


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## Jank (Jan 27, 2007)

"_My data has the pilots manual for the P47B,C,G and early Ds showing a time to climb to 20000 feet with Mil power of approx. 12 minutes_."

This is inconsistent with the following June 18, 1942 test on P-47B aircraft No. 41-5902.

P-47B Performance Test

In have the same manual. I see the data you are referencing and do not know how to reconcile except that it appears inconsistent both with the comparison between the P-47C / F4U-1 and the report on the specific aircraft linked above.

I do think the F4U-1 had a low altitude advantage that below 7,500ft was probably enormous. That low altitude advantage of the F4U-1 is enough to shave a considerable amount off the 0-20,000ft figure when compared to the Thunderbolt. Of course, a considerable advantage in climb below 7,500ft is of no value when fighting between 18,000 and 26,000ft. Put differently, if the climb advantage is extinguished well below 18,000ft, what's the value of factoring in that quick sprint up to 7,500ft? (Yes, I know that if you are an interceptor, the time to altitude can be critical in meeting the threat.)

I don't think anyone is arguing that below 20,000ft the P-47 is superior. Above 20,000ft is another story though. 20,000ft on up is a big space within which the F4U-1 just wasn't designed to and did not excel.

The Joint Fighter Report commented that above 25,000ft, the P-51 was no longer the P-47's superior either for that matter.

In fact, in ranking the "Best all around fighter above 25,000ft" the votes tallied as follows:

1) P-47 (45% of the vote)
2) P-51 (39% of the vote)
3) F4U-1 (7% of the vote)
4) F6F (3% of the vote)

The Joint Fighter Report, it should be noted, was biased heavily in favor of naval fighters. And even so, the F4U-1 mad a very poor showing in the above 25,000ft category. 

To be fair though, it compared late war models of the above four fighters. I realize you are discussing early war variants so perhaps I have strayed somewhat.


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## Jank (Jan 28, 2007)

Let's not forget that the P-47 also had a full 1/3 more firepower as well. That's not insignificant.

Think of it this way. Imagine two cruisers having single turrets both fore and aft. One cruiser has turrets housing three 5" guns for six guns total. The other cruiser is outfitted with turrets that have four 5" guns for a total of eight.

Which cruiser would you rather take a broadside by?


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## Jank (Jan 28, 2007)

"_This was the 4th fighter group and some of the 4th pilots refused to fly the P47. "There are crashes, dead stick landings, mid-air fires, bailouts and gear collapses on the runway. Some pilots die in operational accidents._"

I don't recall the Jug getting pegged with a nickname equivalent to "ensign eliminator" which, by the way, was not specific to carrier operations. 

"Nazi eliminator" perhaps.

Even with it's enormous size and weight, the P-47 managed to rack up a 4.6:1 air to air kill record against a foe that understood marshalling tactics on a group level. (as opposed to the foe that Corsair pilots faced) Moreover, that record was established, for the most part, before the Thunderbolt saw its role shifted to ground attack and thus was during a period when the Germans weren't far outnumbered by American fighters as was the general situation with the P-51. Thunderbolt pilots commonly found themselves outnumbered by their adversary.


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## davparlr (Jan 28, 2007)

renrich said:


> I would like to see backup on P47B operations in Oct. 42. My data shows the first operational mission was on March 10, 1943. 14 P47s and 12 Spits over France. This was the 4th fighter group and some of the 4th pilots refused to fly the P47. "There are crashes, dead stick landings, mid-air fires, bailouts and gear collapses on the runway. Some pilots die in operational accidents. On this first sweep radio interference problems are encountered. Plane to plane communication is impossible." The first official operation with the 8th air force is on April 8, 1943. The Corsair's first operational mission was on Fe. 14, 1943.




My data shows the P-47B production units starting to appear in March of 42 and deliveries were made to the fighter group in June, 1942, and production P-47Cs starting in Sept. 42. I also have data that shows P-47Cs arriving in Europe in late 42, and having their first major combat in April, 43. I have no data on the operations of the P-47B.

*Classic Military Warnings*

"Aim towards the enemy" - Instructions printed on U.S. Army Rocket Launcher


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## davparlr (Jan 28, 2007)

Jank said:


> Max Speed at S/L - 353mph (Corsair) 340 mph (Thunderbolt)
> 
> Max Speed at 20,000ft. - 405mph (Corsair) 415 mph (Thunderbolt)




Flight test data I have seen from SpitfirePerformance for late P-47D (Tail No. looks like 42-26167)/F4U-1 (Tail Number looks like 13978) has:

Max Speed at S/L - 365 mph (Corsair) 347 mph (Thunderbolt)

Max Speed at 20k ft - 430 mph (Corsair) 437 mph (Thunderbolt)

*Classic Military Warnings*

"When the pin is pulled, Mr. Grenade is not our friend" - U.S.M.C. training.


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## Jank (Jan 28, 2007)

Do you have a link? There'a a lot of data on that site.


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## Jank (Jan 28, 2007)

I see it now. That P-47D clocked 444mph at 23,200ft and had a climb rate of 3,260fpm at 10,000ft. Moreover, it was still pulling 3,000fpm at 20,000ft! 

It was with 44-1 fuel.

Do you have a link to the specific test for the F4U-1?


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## Jank (Jan 28, 2007)

I see data for a late war F4U-1 No. 17930 (you mentioned 1397) in 1944 with water injection. 

http://www.wwiiaircraftperformance.org/f4u/f4u-1-17930.pdf

S/L Top speed 365mph
20,000ft Top Speed 430mph
Top Speed 431mph @ 21,000ft

Maximum climb at S/L 3,210fpm

They installed a new, more efficient propeller and the report stated that, "The above difference in performance is attributable partly to the better efficiency of the new propeller ... and modified cowl flap arrangement." 

It was a test of and report on improvements not existing on a production Corsair and the P-47D test, while a production stock aircraft, was with special fuel. 44-1 is the 100/150 grade fuel. I do not know if it saw use as it fouled up the Mustangs pretty bad.


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## Jank (Jan 29, 2007)

It appears that the 44-1 fuel was in fact employed by Thunderbolts after all. 

From: 150 Grade Fuel

In late Winter 1944 the Allied Expeditionary Air Force (A.E.A.F.) decided, pending further trials, not to employ 150 Grade Fuel for Overlord due to spark plug issues, however, it was intended that 150 Grade would be used when proved satisfactory. 17 Meanwhile, cross channel operations by two squadrons of P-47’s and one P-38 using 150 Grade fuel revealed an increase of speed and climb characteristics at the expense of spark plug difficulties. 18 The Production Division was directed on 28 March 1944, under the authority of the Commmanding General, Army Air Forces, to modify all P-38, P-47 and P-51 airplanes in the United Kingdom for the use of Grade 150 fuel, with the necessary modification kits to be shipped to the European Theater of Operations within 30 days. 19

Successful service tests led in May 1944 to the Eighth Air Force Fighter Command requesting that it "be supplied immediately with grade 150 aviation fuel for use in P-47, P-51 and P-38 planes". 20 Deliveries of Grade 100/150 aviation fuel to AAF Stations commenced within a week of the landings in France. 21, 22 The change over to 150 grade fuel necessitated the resetting of all aneroid switches on the P-51s.

...

150 grade fuel continued to be used by 8th AF units through 1944. 24 The WER engine limitation for the P-51 continued to be 72" Hg. 25 Eighth Air Force Fighter Groups converted to a new blend of 150 grade fuel, with increased amounts of ethylene dibromide (1½ T) in early 1945. 26 P.E.P, as the new fuel was called, was tried in order to remedy lead fouling of spark plugs. While spark plug fouling was eliminated, PEP was found to have an undesirable effect on valve seats. As a result of excessive maintenance required on the V-1650 engines, General Doolittle of the Eighth Air Force decided in late March 1945 to revert to the normal 100/150 (1 T) grade fuel. 27

...

Technical Operations, Eighth Air Force issued a 4 April 1945 memorandum in which 100/150 grade fuel experience in the Eighth Air Force was summarized. It is reproduced in full below:

1. The following is a summary of 100/150 grade fuel experience in Eighth Air Force.

2. a. This fuel was first service tested by Technical Operations Section, this headquarters, in October 1943, said service test lasting through until March 1944, at which time it was recommended that if extra performance from P-38, P-47 and P-51 aircraft was desired it could be secured by the use of this fuel. It was pointed out at that time that the only apparent deleterious effect of this fuel on any one of the three types was the extra lead fouling of spark plugs.

b. A decision was made in May 1944 to have all fighter units supplied with this fuel no later than 1 June. As of that date operations with this fuel continued until approximately 1 February 1945 when all fighter units switched to “Pep” (100/150 plus 1.5 T’s ethylene dibromide). As of 1 April 1945 all units switched back to 100/150 fuel containing 1.0 T ethylene dibromide.

3. At the time the 150 grade fuel was first used all three fighter types listed above were in operational use by this Air Force. Shortly after June 1 P-38 units were re-equipped with P-51 type aircraft so that experience with 150 grade fuel in P-38 aircraft is limited. Gradually, conversion of P-47 outfits to P-51’s took place during the Summer and Fall of 1944, and as of approximately 1 November only one P-47 group remained in this Air Force. 

4. Maintenance difficulties can be summarized as follows:

a. P-38 (V-1710 Engine).

Spark plug leading was increased. The extent of this leading was such that plug change was required after approximately 15 hours flying. This conditions was aggravated considerably by low cruising powers used to and from target areas, while trying to get the maximum range possible. It was found, however, that regular periods of high power running for a minute of two in most cases smoothed out any rough running engines unless the cause was other than leading.

b. P-47 (R-2800 Engine).

Spark plug fouling was the only maintenance difficulty encountered during the period in which 150 grade fuel was used. Spark plug life was reduced by about 50%, the same low power cruising as described above being the principle cause for the extra fouling. No deleterious effects on diaphragms, fuel hose or any other rubber of synthetic rubber materials were noted.

c. P-51 (V-1650 Engines).

The same type of lead fouling as described in a and b above happened in the case of the P-51 except that is was probably more serious than in either of the other two types. Using 130 grade fuel with 4½ cc. of lead, the average operational P-51 could last 5 missions (roughly 25 hours) before the fouling required plug change. With 150 grade fuel containing 6 cc. of lead, 10 to 12 hours, or normally 2 missions, was the average length of time between spark plug changes or cleaning. At various times in the six months of operation of P-51 aircraft on 150 grade fuel many other maintenance difficulties were attributed to the fuel, but final analysis proved that the only real effect of the fuel was the lead fouling. Some units maintained that they had some deteriorations of seals, but this was not borne our throughout the command, nor was there any concrete evidence that it existed in the units.

The excessive fouling of spark plugs usually exhibited itself in roughing up of engines after a couple of hours of low power cruising. Periodic bursts of high power in most cases smoothed the engine out. However, if the engine was allowed to go too long a period without being cleaned out, the accumulation of lead bromide globules successfully withstood any attempts to blow them out. In some instances, long periods of idling while waiting for take-off and a failure to use high power on take off resulted in loss of power during take-off run and in some cases caused complete cutting out with subsequent belly landing. The cases of cutting-out on take-off definitely attributed to excessive fouling were comparatively few, although numerous enough to list it as an effect of the extra lead.

As a result of several months operational use with the fuel, an SOP – designed to reduce power failures on take-off, leading troubles in flight, and other things which were causing early returns and abortive aircraft – was published. This is inclosure no. 1. Almost immediately after this section published this SOP practically all of the troubles then existing ceased, although it was necessary to change plugs after each two missions or thereabouts.

In an effort to reduce the lead fouling, tests were conducted by this section with 150 grade fuel containing 1.5 T’s of ethylene dibromide. A total of about 120 hours was run by this section and the three squadrons given the “Pep” fuel for accelerated service tests. The results of these service tests showed a considerable reduction in lead fouling with no apparent effects otherwise. As a results, all fighter units of the Air Force were put on Pep fuel late in January 1945. About thirty days thereafter a sharp increase in valve trouble was experienced with the V-1650 engine. Inspection of engines at overhaul revealed that the hydrobromic acid was eroding the silchrome valve seat inserts to such an extent that after approximately 100 hours of operation all the valve clearance was gone. This 100-hours is the minimum life some engines going 170 to 180 hours before this condition prevailed. There are no other deleterious effects of this fuel noted. As of 1 April 1945 fighter units of the Air Force returned to the use of 100/150 grade fuel containing 1.0 T of ethylene dibromide. 28


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## renrich (Jan 29, 2007)

Interesting data on F4Us in ww2: Corsairs shot down 2140 enemy a/c for the loss of 189 Corsairs. Sorties were 64051, 54470 from land bases, 9581 from carriers. Additional F4U losses were 349 from ground fire, 230 from other, 692 on non-operational flights and 164 in crashes on airfields or carriers.


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## renrich (Jan 29, 2007)

Some of the F4U4s were built with 4- 20mm cannon rather than the 6-50s. Their throw weight would be 11.6o lb/sec. The 8-50s of the P47 yielded a throw weight of 12.72 lb/sec. The P47B-N carried 267 rds per gun which gave them a firing time of 17.8 sec. The F4U1-4 carried 400 rds per gun which gave them a firing time of 26.7 sec.


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## bigZ (Jan 29, 2007)

What was the US pilots opinion of using the 20mm cannon on the Corsair? Or was this just for the RN pilots?

Personally I would prefer the cannons even compared to 8-50's on the P47.


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## renrich (Jan 29, 2007)

I don't know but I do know that the early use of the 4-20s on the F4U-1Cs was not met with great enthusiasm. However a lot of the 4s and all othe 5s used in Korea were armed with the cannon. Incidently some of the Hellcat night fighters were armed with 4-50s and 2-20mms.


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## renrich (Jan 29, 2007)

Hope I am not out of order by posting this here but has this group ever discussed who was the greatest fighter pilot of all time. My vote would go to Marseille(hope I spelled his name right.)


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## Jank (Jan 29, 2007)

"Personally I would prefer the cannons even compared to 8-50's on the P47."

The USN conducted tests of the 20mm and .50 and determined that at close range, a 20mm round had 3X the destructive power. This was reduced to 2.5X at longer ranges.

With the ammunition loads carried, the P-47 had more seconds of fire before she went dry compared to a four 20mm package.

At any rate, I think that four 20mm's were probably a superior package although I never heard of a pilot who didn;t think he had tremendous firepower with eight .50's. Pilots often reported their targets disintegrating or just exploding under fire from the approximately 100 round per second stream of armor piercing incendiary ammunition.


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## Jank (Jan 30, 2007)

Renrich said, "_The P47B-N carried 267 rds per gun which gave them a firing time of 17.8 sec. The F4U1-4 carried 400 rds per gun which gave them a firing time of 26.7 sec._"

Do not confuse what the maximum capacity was as opposed to what might have been carried.

Your "Pilot's Flight Operating Instructions - P-47B, C, D and G", January 20, 1943, states that the capacity is 425 rounds per gun. Page 38C - "The maximum load is 425 rounds each."

Also, note this test data that included F4U-1, -4 and P-47D. Throughout, they indicate full loadings of 2,400 rounds for the six gunned Corsair (400 rpg) and 3,400 rounds (425 rpg) for the Thunderbolt. 
http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf

Did you know that the P-47N was designed to carry bomb loads of 3,700lbs (1,600lbs under each wing and 500lbs under the belly) and the P-47M was designed to carry bomb loads of 4,200lbs (1,600lbs under each wing and 1,000lbs under the belly)? Also, the P-47N had the capacity to carry *500* rounds per gun. 267 "Normal" and an additional 233 rounds in "Overload" condition. (Republic Aviation Performance, Dimensions and Capacities manual for P-47N and M.) Also, see pgs. 56-58 of P-47N Pilot's Manual which states that the maximum ammunition load is 500 rounds per gun.

That's 25% more capacity and a 25% longer firing time than the Corsair (500 rounds as opposed to 400 rounds) coupled with a third more firepower to begin with (eight as opposed to six guns).

Back to the issue of capacity vs. practice, I don't think P-47N's ever did carry 3,700lbs in bombs (1,600lb bombs were not standard but did exist). But just because the P-47N didn't actually carry more than 2,500lbs of bombs didn't therefore set the maximum bomb capacity at that point.


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## jpatrick62 (Feb 9, 2007)

jank,

Thanks for posting the link. By those numbers, the F4U-4 has a real hot ship!


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## renrich (Feb 9, 2007)

Charles Lindberg took off and bombed with a Corsair in the Pacific with 2-1000 lb bombs and 1-2000 lb bomb. He also stated that the visibility from the cockpit of an early Corsair was no worse than the visibility from The Spirit of St Louis. There are some interesting stories about Lindberg and his flying of early model Corsairs in WHISTLING DEATH by Boone Guyton. Guyton did much of the test work on the F4U and is responsible for the difficulty that small and short pilots had in the Corsair cockpit. Guyton was 6ft 4in tall. Lindberg had a lot of input and did a lot of flying during the development of the P47 also. It would have been interesting to have gotten his opinion about the merits of the 2 fighters.


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## Treeseeker300 (Aug 31, 2007)

Heres some info on the F4U. I found it very informative and in all honesty i think the Corsair was a slightly better plane. =) 

Chance Vought F4U-4 Corsair

Since they are both American planes, I would favor either or against an enemy plane any day of the week


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## DerAdlerIstGelandet (Sep 3, 2007)

Treeseeker300 said:


> Since they are both American planes, I would favor either or against an enemy plane any day of the week



Why is that?

There were great British aircraft out there as well let alone great Luftwaffe aircraft as well.


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## Screaming Eagle (Sep 4, 2007)

I agree both sides had some great aircraft, although my favourite fighter is the P-51D Mustang


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## Snorts (Jul 6, 2009)

First post:

My Dad flew the P-47N. He engaged in mock combat with the F4U's all the time, in both a D model and an N model, and against the -4's as well as earlier marks.

For practice flights his squadron would fly south from Dover Delaware on loooong training flights. On the way back they would often engage Navy Units in their birds in dogfights.

My Pop's thoughts on all this, as captured in several oral history sessions.

The Corsairs wanted the fight below 15,000 feet, the Thunderbolt pilots above that. Taunting would ensue until one group said heck with it and climbed or dove to engage.

In a D model P-47 Pop said it had a performance very similar to earlier Corsairs. And, he couldn't tell by looking which model F4U he was facing. That said, what a -4 pilot would do was to lure the P-47 into a half or quarter turn, high G, then roll wings level and zoom climb. The -4 outrolled and out zoomed the P-47D's, and as the D fell off the Corsair had them.

In the N model when the -4 did that, the N outrolled and out-zoomed the Corsair. he said the Jug would catch and soar past the Corsair, and he would wave. The Corsair pilots would wave back with one finger. 

Dad said you did NOT turn with the Corsair, they could out turn the Jug, any version. But he dismissed that as insignificant, a Jug pilot never thought of getting into a luffberry anyway. Dive, zoom, roll, those were what the Jug did well. He also said the lead computing sight was a great piece of equipment.

According to Dad, the poor sustained climb rate of the P-47N meant nothing. He was flying into combat at the altitude he wanted, and the zoom climb was what was used in aerial combat, and the P-47 excelled at that. 

He dearly loved his P-47's. But before one thinks he was blindly loyal to it, he freely admits the P-51 was better below 30,000 feet. Even at that, he said that above 30,000 feet with the Mustang "you still had an airplane". In other words, it was still capable.

I have it on tape, me asking Dad to pick the plane that did things better, P-51 or his favorite, the P-47.

Speed..."Mustang" (According to Dad, the N did not outrun the Mustang until above 22000 feet or so. The D models could not outrun it at any altitude. He flew P-51s with 145 octane, and he said it made the acceleration, climb rate and top speed down low even more of an advantage for the Mustang).
Acceleration..."Mustang"
Roll rate...."Mustang"
Dive acceleration..."Mustang"
Dive speed....a long pause. Then a tired sounding "Mustang".
Zoom climb...."Mustang". His eyes lit up on that. According to him, the P-51 was fantastic in the zoom, and he felt it was the single best attribute of the Mustang.
Visibility..."Mustang"
Turn..."Mustang"
Dad tired of this, and began talking. Basically he told me that sure, the P-51 did most things better than the Jug, except bring you home. According to him, Pilots liked that better than any performance or maneuverability advantage, and liked the added firepower as well. Tough with a great punch. He would have preferred flying the P-47 in combat.

The war ended as he was, literally, on the way to Ie Shima. He and my Mom were part of the occupation, and Dad was assigned to a P-51 photo recon unit in Japan, getting in his Mustang hours. *Edit* Again, per the old Man...the Recon versions of the Mustang ALWAYS flew like they had a full fuselage tank due to the camera location.

Dad is deceased, after serving in three wars, WW2, Korea where he actually flew the B-26, and Viet-Nam. Take this for what it is worth, it is offered with no apologies or caveats.

I like this forum!


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## drgondog (Jul 6, 2009)

Snorts said:


> First post:
> 
> My Dad flew the P-47N. He engaged in mock combat with the F4U's all the time, in both a D model and an N model, and against the -4's as well as earlier marks.
> 
> ...



Snorts - this is almost verbatim the same run down from my father who flew all the USAAF birds except P-39 but only flew P-51B and D in combat.

He differed on your dad's summary of Roll giving the edge to the 47D and M until high speed and an overall edge to the Jug above 30,000 feet when the Merlin started running out of power. He did say the 51H was definitely superior to the D and most notably in stability, acceleration, climb and and speed, but also noted the 51B seemed to be nearer in performance to the H than the P-51D's..

AFAK he never did a terminal dive in either a P-38 or a P-47 so had no comment on max dive speed.

The 355th FG, when he was group CO, was rumored at one time to be headed 'east' from occupied Germany just before the war ended in PTO and he snuck more late model P-47D and M time from the 405th FG which was fairly close to Gablingen, GY at the time.

Before he had the 35FG in Japan in 1948, he had some time in P-47N and P-51H in 1946-1947 before we moved to Japan - the 35th was equipped with P-51D/K


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## Catch22 (Jul 6, 2009)

to your dad!

Welcome aboard, and great info!

EDIT: Missed drgndog's post, should have quoted.


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## zoul310 (Jul 6, 2009)

Snorts said:


> Dad tired of this, and began talking. Basically he told me that sure, the P-51 did most things better than the Jug, except bring you home. According to him, Pilots liked that better than any performance or maneuverability advantage, and liked the added firepower as well. Tough with a great punch. He would have preferred flying the P-47 in combat.
> 
> 
> Terrific post.
> ...


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## Marshall_Stack (Jul 6, 2009)

Great post Snorts and Drgondog. Interesting details....


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## Snorts (Jul 7, 2009)

drgondog, thanks for a great post of your own. 

A bit of clarification....Pop agreed with your Dad, the P-47 was better than the Mustang above 30,000 feet. Not that the Mustang was poor, the P-47 just came into its own in the thin air.

Roll rate, who am I to argue? Just reporting what the Old Man said. It is really cool to compare the two opinions, though. I think the point of the story there was that the P-47N rolled better than the P-47D he flew.
He did tell me he remembered cruising along at high speed in the Mustang, throwing the stick over, and banging his head on the opposite canopy side. 

Dad apparently did some terminal dives in the P-47. He said that the one thing that separated it from all the other props he flew was that you KNEW it would hold together. You split essed with absolute confidence
He never flew the P-51B, H or K versions, just the D' and the F6. He did say that if you were flying with 145 octane fuel, it was like a different airplane. They also 'blew out the engines' every 20 -30 minutes with the 145 octane to avoid spark plug fouling.

He also described the P-47 as a Cadillac, with a roomy cockpit, and lots of pilot comforts. The P-51 was 'worn' by the pilot, tight fitting and cramped. You also wore gloves in it, because unfinished metal edges would cut you. "Thus the "Spam Can" nickname. When asked, he said the instrument layout for both planes was good.

I quizzed him pretty thoroughly on the charge that the P-51 had high stick forces. I wish I had a video. He wrinkled his forehead and said, "no more than any of the other planes I flew." Constant trimming was necessary when flying the Mustang, and if you didn't have it trimmed right, THAT could cause high stick forces.

Dad also flew all the AAF types except the P-38. He got a ride in a P-39, and had quite a bit of time in the P-40. He also got a flight or two in the P-36. Later in his career he flew the F-86, F-86D, P-80, T-33 and F-101B Voodoo.


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## Marshall_Stack (Jul 7, 2009)

Snorts said:


> drgondog, thanks for a great post of your own.
> 
> A bit of clarification....Pop agreed with your Dad, the P-47 was better than the Mustang above 30,000 feet. Not that the Mustang was poor, the P-47 just came into its own in the thin air.
> 
> ...



Snorts,

I am envious of your Dad!

I guess that the P-47N rolled better since it had the clipped wings. I was surprised about the comment of the P-47N being able to out climb the P-47D in the zoom. The P-47N was heavier due to the extra fuel tanks.


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## renrich (Jul 7, 2009)

I had an uncle who was an IP in P47s (and P39s) He said that when in mock dogfights they got waxed by Corsairs. I keep hearing about P47s having good roll characteristics but in Dean's "America's Hundred Thousand," he said the roll rate of the P47 was nothing to shout about. Would not the P47N with the longer wing span have a poorer roll rate than the P47D?


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## DAVIDICUS (Jul 7, 2009)

I think the "N" had larger control surfaces on the wings.

Marshall, check out the following zoom climb test of the "D" and "N" models:

http://www.wwiiaircraftperformance.org/p-47/p-47n-zoom.pdf


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## davparlr (Jul 7, 2009)

renrich said:


> I had an uncle who was an IP in P47s (and P39s) He said that when in mock dogfights they got waxed by Corsairs. I keep hearing about P47s having good roll characteristics but in Dean's "America's Hundred Thousand," he said the roll rate of the P47 was nothing to shout about. Would not the P47N with the longer wing span have a poorer roll rate than the P47D?



Two pilots, two planes, different stories. I suspect the altitude at which the mock combat occurred would make a significant difference, and possibly fuel load. His comments about the -4 against the D would conform to your dad's comments.


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## DAVIDICUS (Jul 7, 2009)

Indeed, I suspect such mock combat didn't take place at 30,000 feet.


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## MikeGazdik (Jul 8, 2009)

First of all, thanks to Drgondog and Snorts for some great info. 

2nd, I found out it is important to look at the date posted on the top left. I was reading this whole thread and was thinking "man, just a day and I missed alot!" Then I see this started 4 years ago! Oops.

3rd, This fits in nicely with a paperback I am presently re-reading. ( they stay with me forever) Its about an 8th AF pilot that starts out in Thunderbolts, then switches to Mustangs. He pretty much said what it sounded like Snort's father was saying. The Mustang was better, but in the Thunderbolt he felt safer. I guess when things get ugly, and you are on the receiving end, advantage Thunderbolt !

Another great read, thanks to all!


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## syscom3 (Jul 8, 2009)

Did the P47D-25 or "N" version have boosted controls?


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## renrich (Jul 8, 2009)

It would be interesting to know the amount of air combat that took place above 25000 feet and below 25000 feet in WW2. I am reading a book, "Retribution" by a Brit named Hastings, about the last year of the war against Japan. He quotes an AAF pilot who said that the B29 sounded like it was coming apart when trying to get above 25000 feet with a full load. My hunch is that many of us have the idea that fighters and bombers regularly mixed it up at 30000 feet while the reality may have been much different.


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## DAVIDICUS (Jul 8, 2009)

Renrich has a good point. Combat that starts at high altitude degrades to maintain speed. Tactics that emphasize zoom-climb slashing attacks help but the loss of altitude over time is inevitable.


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## renrich (Jul 8, 2009)

Another point is that, for example one takes two fighters; one has a critical altitude of 25000 feet where it's vmax is at it's best. The other has a critical altitude of 30000 feet where it's vmax is at it's best. The first fighter is superior in vmax and climb at every altitude from SL to 25000 feet. The second fighter is superior in vmax and climb at all altitudes above 25000 feet. The first fighter has a service ceiling of 39000 feet, the second, a sevice ceiling of 41000 feet. Which fighter has the best chance all other factors being equal of winning a fight? The Mustang was considered to be be the best fighter below 25000 feet, the Thunderbolt was considered the best above 25000 feet. Which had the most success against LW fighters? If I am at 30000 feet and want to fight at 25000 feet it is a lot easier to get to 25000 than if I am at 25000 and want to get to 30000.


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## Snorts (Jul 8, 2009)

Thanks to everyone for their thoughts and comments. 
To emphasize...Dad said the P-47N was better in the zoom and rolled better than the D models he flew. And that the tactic the -4 pilots used of a brief hard turn, followed by a quick roll to a zoom were nullified when flying the N.
The Jug pilots wanted to fight the Corsairs above 15,000 feet, the Corsairs below that. They two groups would taunt the other until one dove or climbed and the fight was on. To add to this, the Old Man thought this was funny, the way the two groups knew where their advantage was.
And, as to who won all the time, Dad never really said. He just thought it was funny how what used to work for the Corsairs against the P-47D no longer did against the N.
*Edit* Dad also said the Corsair was a "good plane." He was dismissive of the Hellcat. A lot ot typical fighter pilot bravado there? Maybe. Just reporting the facts as my Dad saw them.


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## syscom3 (Jul 8, 2009)

Snorts said:


> ....was dismissive of the Hellcat. ......Just reporting the facts as my Dad saw them.



Hmmmm ...... some people at the Best Pacific Fighter thread say the Hellcat was tops.


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## Daviducus2 (Jul 8, 2009)

I'm at work right now and can't log in so I have re-registered.

From P-47 Thunderbolt: Aviation Darwinism:

*Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further. In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too.
...
The testing program included determining the maximum range of the fighter. This was done with various combinations of fuel loads and external drop tanks. Ultimately, a test flight was made from Farmingdale to Elgin Field in Florida. The XP-47N took off with two 315 gallon drop tanks hanging from the under-wing hardpoints. Usable fuel in these tanks totaled 600 gallons. Added to the internal fuel load, the N eased off the runway with 1,170 gallons of fuel (usable). At a gross weight of 20,166 lbs., the Thunderbolt headed south in company with a P-47D chase plane. Arriving off the coast, east of Elgin in 3 hours, 44 minutes, the external tanks were dropped. Another P-47D, already waiting at Elgin, took on the N in a mock dogfight that lasted for twenty minutes. The throttle was advanced to military power for 15 minutes of this time, with an additional five minutes in the War Emergency Power (WEP) detent. After these fun and games were concluded the N was turned around and flown back towards Farmingdale. Heavy weather over Long Island caused the plane to divert to Woodbine, New Jersey. Having flown 1,980 miles, total fuel usage was measured at 1,057.5 gallons. There was still more than 112 gallons of usable fuel remaining in the main fuselage tank, enough for another 330 miles ...*

This was a test between a "D" and an "X" but it generally confirms what other posts are indicating. The P-47N had the capacity for 570 gallons of internal fuel. With an "M" loadout of fuel, the P-47N probably had performance that approached the P-47M. 

P-47 Thunderbolt: Aviation Darwinism - The Cradle of Aviation Museum - The Cradle of Aviation Museum


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## renrich (Jul 8, 2009)

D2, my Dean book is packed right now, since I am moving, but when I get situated I will pull it out and recite what his comments about the roll rate of the P47D were. I seem to recall that he said that anything under a four second 360 degree roll was good performance for a WW2 fighter. Of course that varied according to the speed. I got to do a couple of aileron rolls in an L39 once and at 250 knots it could roll 360 degrees in just over one second. When I rolled it, the sensation was that the earth was going around not the plane. Snorts, your comments and recollections are much appreciated.


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## MikeGazdik (Jul 9, 2009)

syscom3 said:


> Hmmmm ...... some people at the Best Pacific Fighter thread say the Hellcat was tops.



With out being able to pull out facts and figures, I would say the Hellcat may have been the best in the Pacific theatre. But obviously these are the Japanese planes that were far inferior, except a couple of the later models which were not built in enough numbers, or flown by experienced enough men, to matter.

I know it has been written otherwise, but I just don't see the Hellcat stacking up against the top Luftwaffe planes, as well as the P-51 or P-47. I think the Hellcat lacked too much speed vs the Focke Wulf and Messerschmitt. And I think its performance at 25k and above was far worse than the Messerschmitt, Mustang , and Thunderbolt. I think from what I recall the Hellcat could turn, what about the roll? 

Im not saying the Hellcat is incapable, it was obvously darn good. But I just don't see it being able to out perform the Republic or North American product in Europe. Or the Spitfire for that matter.


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## renrich (Jul 9, 2009)

Mike, look up Mike Williams' reprint of a US Navy evaluation of the F6F3 and F4U1 versus an FW190A4 for the answer to your question. Vmax is not always the determinant in a fight.


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## Daviducus2 (Jul 9, 2009)

In terms of performance, I don't think the Hellcat could hold a candle to the Corsair but the USN collected lots of data where both Corsairs and Hellcats flew from the same ships at the same time in 1945 against the same targets. The results of this data are surprising - at least to me.

See the "Hardest plane to take down in WW2" thread for an earlier discussion on this subject. I cut and pasted the relevant text of the report below.

Apparently the Corsairs were more than 50% more likely to become losses after suffering AA fire than the Hellcats. (41% vs. 26%) I have also heard some speculation that it had to do with the different oil cooler layout on the Corsair, the design of which was eventually changed in post WW2 production variants as the problem persisted into the Korean conflict.

From Naval Aviation Combat Statistics, WWII

Page 58:

*Thus comparisons are valid between the carrier F6F and F4U totals because they generally operated from the same ships during the same period.
...
Certain tentative conclusions may be reached from these two tables:

(a) The F6F was slightly superior to the F4U in combat, apparently chiefly because of its greater ability to survive damage.*

And on Page 79, Note (e) to Table 29

*The F6F appears to have had considerable advantage over the F4U when flown under the same conditions. Receiving about the same number of hits per sortie in comparable operations, the F6F had a far lower rate of loss per plane hit.*


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## syscom3 (Jul 9, 2009)

Off topic, but I suspect the F4U-4 was able to take on the last of the Japanese fighters that were being produced at the end of the war (assuming they were flown by good pilots, had good gasoline and the plane was built correctly).

The F6F wouldnt have been able to handle them.


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## Vincenzo (Jul 9, 2009)

Daviducus2 said:


> From Naval Aviation Combat Statistics, WWII
> 
> Page 58:
> 
> ...



for page 79
the trouble is attacking a target with enemy AA it too few for tell "under the same condition" as the compilators of report, enemy AA can be a single 7,7 mg or twelve 25 mm guns i dont' see the same condition.

for page 58
i don't see advantage for hellcat, (other the trouble on each comparison)


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## Daviducus2 (Jul 9, 2009)

http://www.history.navy.mil/download/nasc.pdf

See the table on page 78 and the following note "e" on page 79. Note the number of sorties flown from carriers in 1945 with AA present. *22,000* sorties for both aircraft. The report earlier states that the two aircraft were operating from the same ships in 1945 on this data point.

Note (e) - "... when flown under the same conditions. Receiving about the same number of hits per sortie in comparable operations , the F6F had a far lower rate of loss per plane hit."

I think the data speaks for itself and the report does not misread or misevaluate the data. I for one have never seen a more apples to apples collection of data on aircraft combat performance. There is no reason to assume facts not in evidence or entertain notions like Hellcats having faced more 7.7mm fire and Corsairs more 20mm fire.

We all accord great weight to individual aircraft performance tests on certain standardized parameters even though the specific aircraft used in the test could deviate from the norm for that aircraft model. With a massive data population such as here, no such individual aircraft deviations could skew the totals and single mission specific factors that favor one over the other would be washed out in the thousands of sorties flown.


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## JoeB (Jul 9, 2009)

Daviducus2 said:


> See the table on page 78 and the following note "e" on page 79. Note the number of sorties flown from carriers in 1945 with AA present. *22,000* sorties for both aircraft. The report earlier states that the two aircraft were operating from the same ships in 1945 on this data point.


I agree, I find the resistance to this data point very puzzling, and more so the more it's explained just how broad and side by side it was. Rarely is any comparison between two planes as broad and 'apples to apples' as that one. And it's reinforced anecdotally by the F4U's poor reputation for ground fire vulnerability in Korea, and eventual redesign of oil cooler arrangement and uparmoring (in AU-1) to deal with it. There is no valid reason to to doubt that conclusion: F4U distinctly more vulnerable to ground fire than F6F.

On P-47N, I spoke once to the USAF pilot who scored the first USAF victory over a MiG-15 in Korea in F-80 (that the Soviets agree happened, a few days after Russell Brown's famous combat, in which no MiG was actually downed per Soviet records). By interesting coincidence he also flew combat missions over Korea late in WWII, from Ie Shima (near Okinawa) in the P-47N. He was convinced the P-47 in general was superior to the P-51 and P-38, especially the P-47N. This seems to have been a fairly typical pattern for pilots who mainly flew one type, or only flew one type in combat (and not all that many flew more than one of the P-38, 47 and 51 *in combat*, though some did). I guess he'd think P-47N superior to F4U-4 as well.

Joe


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## drgondog (Jul 9, 2009)

MikeGazdik said:


> 3rd, This fits in nicely with a paperback I am presently re-reading. ( they stay with me forever) Its about an 8th AF pilot that starts out in Thunderbolts, then switches to Mustangs. He pretty much said what it sounded like Snort's father was saying. The Mustang was better, but in the Thunderbolt he felt safer. I guess when things get ugly, and you are on the receiving end, advantage Thunderbolt !
> 
> Another great read, thanks to all!



Which book? Ace of the Eighth by Fortier?


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## DAVIDICUS (Jul 9, 2009)

Assuming the massive disparity in survivability between the Hellcat and Corsair was a function of the oil cooling design, as a pilot I think I'd have second thoughts if given the choice between Corsair and Thunderbolt for ground attack / close air support.


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## renrich (Jul 10, 2009)

Yes, it was massive alright, they both flew about the same number of combat sorties although the Corsair dropped more than twice the tonnage of bombs and the Hellcat's were more air to air and the Hellcat lost 553 AC to AAA and the Corsair lost 349 to AAA. Massive, huh?


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## Daviducus2 (Jul 10, 2009)

41% vs. 26% means the Corsairs were *58*% more likely to be losses from AA fire than Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."

41 is .5769 more than 26.

I don't think "massive" qualifies as a mischaracterization but as has been stated above, the data speaks for itself. If you prefer "very large disparity" I stand corrected.

The problem with the point you are making through the data you have posted above is that it lacks the apples to apples aspect of the 22,000 "same conditions" "comparable operations" sorties on which the conclusions in the Naval Aviation Combat Statistics report are anchored.

As JoeB mentioned, the resistance to this is puzzling. I can't think of any other comparative statistical analysis between aircraft that is so well defined and controlled and yet discounted as mere fiction in the absence of a single criticism of the validity of the data. I can't help but wonder what your reaction would be if the situation were reversed such that there were a 58% greater loss rate for the Hellcat. I frankly suspect that if such were the case, you would wholeheartedly agree that such a disparity is indeed "massive." 

Am I wrong?

At any rate, I am sure we can agree that the disparity is very large.


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## JoeB (Jul 10, 2009)

renrich said:


> Yes, it was massive alright, they both flew about the same number of combat sorties although the Corsair dropped more than twice the tonnage of bombs and the Hellcat's were more air to air and the Hellcat lost 553 AC to AAA and the Corsair lost 349 to AAA. Massive, huh?


Download the NASC document from the link above, and look at the actual tables showing results of side by side operations of the same kind. The F4U operational loss rate *per action sortie* from CV's, in '45, was 50% higher than F6F's rate from CV's in 1945. The AAA loss rate *per sortie encountering AA fire* in carrier operations in 1945 was more than that much higher for the F4U. The ordnance dropped *per strike sortie* in carrier operations in 1945 was almost the same for the two types. Prior to 1945 there is no fair comparison because there was no large number of carrier or land based strike sorties for *both* types in the *same* period, but the 1945 carrier results are a statistically quite large sample. I gave the specific table references for each of those statements in the thread on Pacific Fighter. 

It's simply and obviously not valid to counter that evidence with absolute numbers that don't take into account the number of sorties over which a give tonnage or number of losses occurred, and which compare different types of operations rather the same operations.

Joe


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## Daviducus2 (Jul 10, 2009)

_"... the 1945 carrier results are a statistically quite large sample."_

The only thing I would add to JoeB's post is that the data provided is not just a sample of the carrier operations between the two aircraft in 1945 flying from the same ships under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" but the entire population itself. Thus, the data is not subject to statistical sampling errors that can result in a sample not being reflective of the population from which it is drawn.


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## renrich (Jul 10, 2009)

Some thoughts on the infamous(famous) Corsair vulnerability to ground fire possibly because of the location of the oil cooler. First, let me say that it is obvious that the oil cooler in the Corsair was more vulnerable, especially to ground fire, than that of the Hellcat. The Hellcat's was behind the engine and the Corsair's was in the wing which is further back. Anyone who has done much wingshooting knows that a bird is more likely to get hit in the tail than up front because of not enough lead and that had to be true with AA fire, so the further back something is the more likely it is to be hit. We know that 553 Hellcats were lost to AA while 349 Corsairs were lost to AA. !04 less Corsairs but either number is small considering they both flew around 64-65000 sorties each. We know that the Corsair dropped 15621 tons of bombs and the Hellcat dropped 6503 tons. So the Corsair probably flew around twice as many air to ground missions as the Hellcat unless it carried twice as big a load. We know that the Corsair replaced the Hellcat as the Navy carrier fighter because the Navy thought it was better suited as a fighter and fighter bomber. We know that the postwar production of Corsairs continued to have the oil cooler in the wing until the AU was built and I have been informed by JB, whose information sources seem exhaustive and impeccable, that the F4U7, for the French, had the oil cooler behind the engine also. We know that a statistical study by the Navy of comparable missions flown by both AC in the same time frame and in the same area showed that the Corsair was more likely, statistically, to be shot down by AA than the Hellcat on comparable missions. Two questions arise, why did not the USN insist that the oil cooler be relocated on subsequent production and do we know who was flying the Corsairs and Hellcats in the study done near the end of the war.
In 1953, I graduated from high school and I and 5 other of my doughty friends decided to go down to Padre Island, 140 miles away and camp out on the beach for a week. We got down to Padre, which was not developed as it is today, turned south and drove on the beach for about 20 miles and pitched camp at about sundown. We were awakened the next morning by the sound of aero engines, looked out over the Gulf and there were a bunch of blue airplanes lining up to head toward us. They came over us in a not too shallow dive and over a point inland of us and pulled up. with the sound of guns and small explosions following. Shortly a gray jeep pulled up with two SPs in it. They said,"did you know you are in a Naval Aerial Bombardment Range." We said "no, we did not see any signs.' They said,"you could get the _____ blown out of you here." Us being smart asses, we declined to leave and apparently they couldn't make us so they left and we watched the show. The area of impacts was probably a half mile inland. We went back there late in the afternoon and looked at practise bombs, rockets and empty shell cases. While watching this show several days in a row, we noticed that some of the airplanes held their dive a lot lower than others and we would say,'there is one pulling out early so he must be married."
The reason for this story is that I have an idea that the majority of the Corsairs in the evaluation by the Navy were flown by Marines and the majority of the Hellcats were flown by Navy pilots. The Marines were noted for pressing their attacks in close in order to achieve more accuracy because they were likely to be supporting other Marines on the ground, whereas the Navy did not have quite as much "skin in the game.' That was true in Korea also as the guys on the ground seemed to think the Marine pilots pushed it a little harder than the Navy or Air Force guys. That factor just might account for some(not all) of the apparent difference in vulnerability between the two AC. Another factor in the comparison between the two AC is that the Corsair could and did act as a dive bomber in WW2. I believe that a dive bomber in an 85 degree dive is easier to hit by a resolute gunner( theJapanese were anything if not resolute) than an airplane coming in at a low angle. I have seen combat film of, I believe, Corsairs dive bombing at Okinawa. They looked kind of strange with their landing gear hanging down. Hits in the wing where the oil cooler was would be likely in a dive also.
Incidently, the fun loving pilots of those blue airplanes decided to give us a thrill. One buzzed us in a Bearcat at about 50 feet over the surf while we were swimming and another guy either dropped or fired a dummy something which made a loud splash and geyser in the water about 100 yards away. We got a kick out of it.


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## Daviducus2 (Jul 10, 2009)

Note (e) on Page 79 states:

(e) The F6F appears to have had considerable advantage over the F4U when flown under the same
conditions.* Receiving about the same number of hits per sortie in comparable operations, the
F6F had a far lower rate of loss per plane hit.*

If we assumed that the Corsairs were flown primarily by daring, committed, "skin in the game" Marines and the Hellcats by the Navy, one would expect those less brave/daring/comitted Navy pilots to escape in their Hellcats with _far fewer_ hits per sortie under the same conditions in comparable operations. No? 

Let's take the Marines out of it entirely and focus just on those less brave/daring/comitted men in the Navy. Let's also disregard same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" too as that's just a bunch of malarky designed to confuse us and lead us astray from Corsair worship.


For the entire war, in all operations, Navy carrier pilots lost Hellcats to AA fire at a rate of 1 per 116 sorties.

For the entire war, in all operations, Navy carrier pilots lost Corsairs to AA fire at a rate of 1 per 70 sorties. 66% higher loss rate for Corsair.

For the entire war, in all operations, Navy land based pilots lost Hellcats to AA fire at a rate of 1 per 309 sorties.

For the entire war, in all operations, Navy land based pilots lost Corsairs to AA fire at a rate of 1 per 254 sorties. 22% higher loss rate for Corsair.


Perhaps the less brave/daring/comitted men in the Navy just felt more like Marines when flying Corsairs and pressed their attacks in close in order to achieve more accuracy. Or, maybe there really was very large disparity in survivability between the Hellcat and Corsair, as the authors of the report have pointed out, that may have been related to an oil cooler design that is very different than the Hellcat and Thunderbolt. Maybe the authors of the report, who had access to the data, understood it as well as how and under what circumstances it was collected and obviously knew of the tough, brave reputation of the Marines got it right. The authors took note of the very large disparity between Hellcat and Corsair loss rates under apples to apples circumstances and chalked it up to the Hellcat's greater ability to survive combat damage. 

I see no mention of the facts now entered into evidence by Renrich to attack the Report's conclusions and there are many areas in the report where it comments on facts that account for disparities in the data that on their face, may seem odd.

For instance, on the reasons why carrier borne fighters were far more successful in air combat than ground based aircraft:

"The ruling factor here was the mobility of the carrier forces, their
ability to penetrate deep into enemy territory, concentrating. overwhelming force in surprise
strokes against large sectors of the enemy's secondary air defenses. Land-based aircraft, on
the other hand, were seldom within reach of main concentrations of enemy air strength, except
for a time at Rabaul, where the heavy defenses precluded successful attack on grounded aircraft."


And the report didn't shy away from heaping praise on the Marines either:

"The Marine dive and torpedo bonber force, building up from small beginnings to a substantial
striking power, was the backbone of the anti-shipping and tactical striking force in
the Solomons, contributed greatly to the reduction of the Jap bases in the Marshalls, and later
contributed the bulk of its strength to give tactical air support in the reconquest of Luzon
and the southern Philippines. During late 1942 and early 1943 its few planes were devoted mainly
to stopping Jap naval and transport vessels from reinforcing Guadalcanal. Later it carried
its anti-shipping strikes to Bougainville, and in early 1944 cleaned the last Jap ships out of
Rabaul. Meanwhile as its force expanded it built up its attacks on nearby airfields (Munda and
Vila), gave heavy direct support in the New Georgia and Bougainville campaigns, and made the most
accurate and effective attacks in the campaign for destruction of the Jap base at Rabaul. In
March and April 1944 it was a major factor in turning back the Jap counter attacks on Bougainville,
doubling its previous volume of activity, then returned to neutralization of the entire Bismarck
area. In late 1944 the Marine SBDS were largely withdrawn from the Bismarcks area for transfer
to Luzon, where they began their biggest, though not their most important, job of the war."


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## MikeGazdik (Jul 10, 2009)

drgondog said:


> Which book? Ace of the Eighth by Fortier?



Yes sir. I enjoyed the book everytime I read it.

And on to the argument of Corsair vs Hellcat. I don't have a doubt that the Corsair was more likely to be critically damaged than the Hellcat. And I didn't mean to send this thread off into another direction by my Hellcat comment. 

I know Vmax isn't everything, but it is something. And I think it would matter when fighting the faster Luftwaffe planes. The Hellcat had the speed advantage against most of its Japanese adversaries, but it would lose that from its bag of tricks if used in Europe.


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## lesofprimus (Jul 12, 2009)

All this talk on one document concerning the Hellcats survivability vs the Corairs got me thinking about one specific bit of info again and again:

Pilot protection....

All during the discussion, the info states "the F6F had a far lower rate of loss per plane hit." Could there be some disparity because many of the Corsair pilots were getting hit as opposed to a less number of Navy guys in their Hellcats, possibly due to their attempt to get closer and deliver the ordinance on target with a higher probability??? 

The Corsair was also a larger target for enemy gunners to aim at... I wonder which aircraft had the higher attack speed when delivering munitions..... I would assume the Hellcat was faster going into the attack, which would have made it harder to hit and easier to survive in during ground attack duties...

Which plane had more armor protection for the pilot???

There are too many variables involved in such a comlicated comparison to just say the oil coolers were the reason.... Some very not-to-bright guys in the Navy came to this very abrupt conclusion Im sure....

Which plexiglass canopy protected the pilot better???

Which headrest deflected shrapnel more effectivly???

Also, if the planes were brought down by enemy ground units, they usually crashed in enemy held territory and were thus unavailable to US investigation as to why they went down, oil cooler/pilot trauma or whatever reason... Too many variables involved for me too make this decision soley based on loss ratios....

Great discussion none the less fellas...


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## JoeB (Jul 12, 2009)

Oil cooler arrangement was the general supposition for why the F4U had a higher loss rate than other radial a/c against ground fire. It's true that that's not clearly proven as the reason, while the F4U's higher AA loss rate in similar conditions is pretty clearly proven. But if you look again at NASC, the FM's loss rate to AA in '45 carrier operations was similar to the F6F's, the F4U's rate was high, not the F6F's especially low. Similarly in Korea the comparison was the much higher loss rate of F4U-4 to AA compared to the AD, either of USN units on carriers or of USMC landbased units (which both operated both types). The AD was quite a bit larger plane than either F6F or F4U, FM quite a bit smaller, but the general picture isn't one of size directly determining AA loss rate, but rather the F4U sticking up above other naval radials in AA loss rate. So it does make more sense to look for particular features of the F4U as the explanation, rather than particular features of the F6F.

As Davidicus said, the result is not dependent on considering USMC v USN units. I'd add that the same is true for the operational loss rate comparison in 1945, that of USMC F4U units flying from CV's was only slightly higher than for USN F4U units flying from CV's, but both were around 50 % higher than the F6F's rate from CV's: clearly the plane not the pilots. USN and USMC pilots of late WWII were similarly trained, so it would be surprising if they had much different results in the same a/c in the same conditions, and so not surprising there's little evidence of that.

Joe


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## drgondog (Jul 12, 2009)

MikeGazdik said:


> Yes sir. I enjoyed the book everytime I read it.
> 
> QUOTE]
> 
> ...


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## drgondog (Jul 12, 2009)

lesofprimus said:


> All this talk on one document concerning the Hellcats survivability vs the Corairs got me thinking about one specific bit of info again and again:
> 
> Pilot protection....
> 
> ...



These are very good questions - which have also given me pause. The F4U (and Mustangs) were down in the dirt both in WWII and Korea. I KNOW the Mustang had to be more vulnerable to ground fire but the number of aircraft destroyed per loss was almost double the Jug and more than that vs Lightning - which says nothing until you can parse the number of low level sorties of aircraft attacking an airfield. 

Ditto the F4U vs F6F. I suppose the USN may have had some sense of the mission profiles but it would be interesting for example to look at losses at Okinawa where the AA was heavy and the fighters were at very low level. Were more F6F's flying CAP for the fleet while the Corsairs were getting singed on the deck?

JoeB - do you know?


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## DAVIDICUS (Jul 12, 2009)

_Could there be some disparity because many of the Corsair pilots were getting hit as opposed to a less number of Navy guys in their Hellcats, possibly due to their attempt to get closer and deliver the ordinance on target with a higher probability???_

I addressed that excellent point earlier. Under the same conditions, flying in comparable operations, the two aircraft received about the same number of hits per sortie. Differences in daring low level attacks, approach speed, plane size, etc. should have manifested itself in a fewer hits per sortie suffered by Hellcat pilots. 

Note (e), Page 79:

*...when flown under the same conditions. Receiving about the same number of hits per sortie in comparable operations, the F6F had a far lower rate of loss per plane hit.*

Interesting other points that have been raised.


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## JoeB (Jul 12, 2009)

drgondog said:


> Ditto the F4U vs F6F. I suppose the USN may have had some sense of the mission profiles but it would be interesting for example to look at losses at Okinawa where the AA was heavy and the fighters were at very low level. Were more F6F's flying CAP for the fleet while the Corsairs were getting singed on the deck?


The figures are damaged suffered and losses per sortie encountering AA. So it should basically correct for mission profile differences. It wouldn't include pure air to air sorties, nor total milk run ground attack sorties. And 1945 carrier sorties only, so cuts out a lot USMC operations on Okinawa (which I doubt was heaviest AA loss environment anyway, that would probably have been going after airfields in Japan, as it had similarly been in ETO). And as mentioned already stats are given for both a/c damaged and lost, and rate of damage was similar, undercutting any assumption of a hidden difference in average mission profile or tactics between the two types on 'sorties encountering AA'. The main difference was % of a/c hit by AA which didn't make it back, which was much higher for the F4U, and that's actually the succinct point made in the notes to the NASC table, as quoted above.

Joe


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## Amsel (Jul 12, 2009)

Marine pilots are Marines first. They tend to get in much closer for air supprt, and stick around much longer then their counterparts, due to really wanting to protect the grunts. This may have a small factor in the numbers as well.


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## JoeB (Jul 12, 2009)

Amsel said:


> Marine pilots are Marines first. They tend to get in much closer for air supprt, and stick around much longer then their counterparts, due to really wanting to protect the grunts. This may have a small factor in the numbers as well.


First statement is true*, but at risk of endless repetition, the statistical disparity can be boiled down to % of a/c hit by AA which were then lost, noticeably higher for F4U's than F6F's (64% more), in side by side carrier operations in 1945. The rate at which F4U's and F6F's were hit by AA, on sorties encountering AA, was about the same (only 4% more for F4U's). So we can state as fact that whatever organization differences existed between F6F and F4U units (many of which were USN anyway) on carriers in 1945, they did not have a significant effect on how often each type got hit by AA when they faced AA. And I see no plausible organizational explanation for a big differences in % of hit a/c which were lost. That pretty much had to be caused by differences in the planes themselves.

*although, the corollary to that which is often assumed, that close support is the primary mission of Marine aircraft, is mainly a post WWII thing, and it's even overstated for post WWII sometimes. Close support of Marines on the ground was a relatively unusual mission for USMC a/c in WWII. Landbased ops on Okinawa were an exception, but among 1945 Marine F4U carrier ops, stats being considered, 17% were from CVE's much of which was off Okinawa. But the rest was aboard the big carriers, along with USN F4U units, where the most common strike target in that period was Japanese airfields. The losses to AA divided by all sorties was actually significantly higher in CV than CVE operations for Marine F4U's in 1945, even though likely a higher % of the CVE missions were strike. Airfields were typically among the most dangerous targets for ground attacking fighters when it came to AA. See NASC Table 15.

Joe


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## DAVIDICUS (Jul 12, 2009)

JoeB, Where does the 64% figure come from? 

I thought the disparity was 58%. The 41% vs. 26% loss rate for Corsairs vs. Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."

Incidentally, the USAAF appears to have also kept tabs on fighter aircraft lost to combat damage broken down by fighter type. The Report of Joint Fighter Conference 1944 mentioned that they had collected data on the ability to suffer combat damage and still return to base.

If there is interest, I will dig out my book and post the discussion which, as I recall, was brief.


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## MikeGazdik (Jul 13, 2009)

drgondog said:


> MikeGazdik said:
> 
> 
> > Yes sir. I enjoyed the book everytime I read it.
> ...


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## JoeB (Jul 13, 2009)

DAVIDICUS said:


> JoeB, Where does the 64% figure come from?
> 
> I thought the disparity was 58%. The 41% vs. 26%


Same info, I was just dividing one loss rate on sorties encountering AA by the other 2.3 per 100 /1.4 per 100=1.64 rather than ratio of % lost of those hit 41/26=1.58. Let's call it 'around 60%' 

Joe


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## drgondog (Jul 14, 2009)

MikeGazdik said:


> drgondog said:
> 
> 
> > Sorry If I have missed it before, your fathers name? I didn't realize he was in the book. Sorry to hear Fortier has passed. I thought the story he told of his brother's B-17 mission was also incredible. Bud seemed to really like the security of the P-47, but it is obvious from the book he loved the Mustang. It is the first hand accounts like in this book, that despite tables and graphs, show the Mustang was THE fighter. Have you ever had a chance to visit thier base (or where it was) in England?
> ...


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## MikeGazdik (Jul 15, 2009)

drgondog said:


> MikeGazdik said:
> 
> 
> > Bert Marshall, Jr.
> ...


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## Messy1 (Jul 17, 2009)

MikeGazdik said:


> drgondog said:
> 
> 
> > Thank you for that information. Yes indeed, Fortier did speak well of your father. Your dad was quite busy to say the least. He sounded like a great man, pilot, and leader. I just re-read the story about his piggy-back ride home in a Mustang....wow!
> ...


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## drgondog (Jul 17, 2009)

I'll post a letter to me from Royce Priest detailing the event in a new thread titled "1st piggy back"


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## Messy1 (Jul 17, 2009)

Thanks Bill!


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## Daviducus2 (Jul 17, 2009)

JoeB, 

I think the problem with comparing Hellcat vs. Corsair vulnerability/survivability in the air to air context is that the performance differences in the two planes is quite significant while the performance differences between the two planes in the air to ground realm really isn't. 

I know that most fighters that were shot down never saw it coming but once the rounds start whizzing by, the Corsair probably had a good edge in evasive manuevering that exceeded the Hellcat with its markedly superior roll and dive performance.

Assuming the very large differential in survivability between the Corsair and Hellcat from AA was the result of the oil cooling design, do you think that design also presented a significant source of vulnerability for the Corsair in the air to air context which was not shared by the Hellcat? It would seem that a plane attacking from behind and above could reach the oil cooling aparatus with strikes at the leading edges of the wings where a cooling arrangement at the bottom of the cowling could not be reached at all. With the system spread from the leading edges of the wings to the engine, it would also seem to present at least a bigger kill zone to a plane attacking from behind and below too.

Do you have any thoughts on this?


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## Sweb (Jul 17, 2009)

My Pop also flew the N with the 92nd FS, 81st FG after the war in Hawaii. He hated the thing. Called it a blivit (2 lbs of crap in a one pound bag). But, he was a former 51 driver so his critique of the plane as a fighter escort was naturally contrasted to the 51. The one thing that irked him most was the Jug's slow acceleration. He always emphasized that point with an imaginary throwing of the throttle to the stop and then clasping both hands twiddling his thumbs as if waiting for something to happen. Typically, he said, all other types had that advantage over the Jug so the dive/zoom climb was an essential maneuver with the Jug if not a survival tactic against a real enemy. He went back to 51s in during the Korean War.


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## drgondog (Jul 17, 2009)

Sweb said:


> He went back to 51s in during the Korean War.



which outfit?


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## JoeB (Jul 19, 2009)

Daviducus2 said:


> JoeB,
> 
> I think the problem with comparing Hellcat vs. Corsair vulnerability/survivability in the air to air context is that the performance differences in the two planes is quite significant while the performance differences between the two planes in the air to ground realm really isn't.
> 
> ...


We'd have to guess almost completely about effect of vulnerability on air-air results, in sharp contrast to the cut and dried figures on AA vulnerability. Maybe buried somewhere, or constructed from individual combat reports, we could find stats on what % of F4U and F6F hit by enemy *aircraft* fire returned, and at what rate each was hit on sorties encountering enemy a/c. But even if we had those stats, air-air has the whole other dimension of offensive effectiveness. To take an easier case, there seems little doubt (except among Thunderbolt true believers) that the P-51D was better at shooting down enemy a/c than the P-47D was, but surely less able to absorb their counter fire. It's still very difficult to quantify those two offsetting factors, though.

To review, F4U's and F6F's showed similar claimed kill ratio's v enemy fighters in all the side by side cases we know. IMO that's probably mainly just because individual pilot capability and other human factors (morale, leadership, tactics) dominated WWII fighter combat results when the a/c were at all similar in capability, and those two a/c were flown by very similar or the same air arms, and just not different *enough* in air combat performance to make any noticeable difference in air combat result. But perhaps an F4U offensive advantage offset a F6F hit taking advantage? could be I guess, just seems hard to prove. The F6F also had the advantage of better visibility over the nose for deflection shooting (as well as carrier landing), there could many subtle factors that all offset one another.

Another USN stat I'd throw in is from Alfred Price "WWII Fighter Conflict" p.59, for the same period as the NASC stats (though I don't see it in that document), where they calculated that across all USN types 85% of those where it could be determined* they'd suffered combat damage in the oil system, did not return. The %'s were generally high for all key systems and the pilot, v just 11% for hits on structure resulting in losses. 

*how could they determine it? a source of possible speculation contained in the stats but still interesting IMO.

Joe


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## DAVIDICUS (Jul 19, 2009)

_ ...85% of those where it could be determined* they'd suffered combat damage in the oil system, did not return._

Interesting. Thanks for commenting on this.


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## Clay_Allison (Jul 20, 2009)

I like the P-47 for several reasons: 

1. The oil cooler on the F4U was vulnerable to ground fire and caused several casualties from fire as light as .30 caliber machine guns.

2. The P-47 was much much easier to land and had good ground handling characteristics. The F4U was the original ensign eliminator.

3. The P-47 had a turbocharger and it had great all-altitude performance with smooth boost from the ground to 40k feet. 

4. The extra two guns gave the P-47 a firepower advantage that many of its pilots thought was significant. It's a shame that they never armed them with cannon but neither was the Corsair until the end of the war.

5. Better downward visibility with the bubble cockpit compared to the F4U, which had very uncomfortable visibility characteristics.


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## drgondog (Jul 21, 2009)

Clay_Allison said:


> I like the P-47 for several reasons:
> 
> 1. The oil cooler on the F4U was vulnerable to ground fire and caused several casualties from fire as light as .30 caliber machine guns.
> 
> ...



The F4U got a Malcolm Hood like bubble in 1944 which gave the pilot excellent visibility. Both ships had big, long, fat nose/cowlings, big fat wings - neither was exceptional in visibility below the horizon.


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## Clay_Allison (Jul 21, 2009)

> Documented sources? I would believe that any aircraft can be brought down with .30 caliber fire but my difficulty in this statement is visualizing USN damage assessment team behind enemy lines at Okinawa and saying 'yep it was a .30 cal to the cooler"



This is from Brassey's Air Combat Reader:






For Dogfighting below 20k feet I'd take the Corsair. For all other things, including ground attack, I'll take the more durable and more versatile Jug. 



> And that made a difference how? The Mustang carried 2 to 4 less .50's than the Jug and destroyed nearly 50% more German fighters in 8 months less operations time.



IIRC the Jug shot down more enemy aircraft than the Corsair.

I have always attributed some of the Mustang's success in shooting down more planes to its endurance, i.e. its ability to take the fight to the enemy sometimes when and where he least expects it. I think increased range created more opportunity to engage the Germans, more engagements led to more kills. 

Both the Corsair and the Jug were equipped with the excellent but fuel hungry R-2800, so I think that's moot. 

I can't prove 8 guns made a big difference, but several WWII pilots I've heard interviewed said they thought it did.


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## drgondog (Jul 22, 2009)

Clay_Allison said:


> This is from Brassey's Air Combat Reader:
> 
> 
> 
> ...



I would rather have 8 than 6 (or four) depending on performance degradation for the extra weight - as a trade off for having more lead to spray. I suspect it made more difference for the guy that didn't shoot as well - (which would be most fighter pilots).

I recall some conversationsamong the Mustang aces in which speculation about 4x 50 in the P-51D coupled with the explosive .50 cal round might have been a really good version of the D.. for the" Experten". I also know the results of the explosive .50 cal were mixed, ranging from acceptable to poor.


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## renrich (Jul 22, 2009)

The P47 was the original "Ground Hugger" and required a much longer distance to get off the ground than the Corsair. That would have been a serious handicap when operating from short landing strips in the Southwest Pacific with the density altitudes prevelant there. In fact, in the ETO, P47s often took off with less than a full load of ammunition because of weight considerations. The fact is that the Hellcat and Corsair flew about the same number of sorties in the PTO. The Hellcat had 823 combat losses and the Corsair had 538. My book is packed right now but assuming that around 11000 of each type were built in WW2 ( which is close), 7% of Hellcats were lost to enemy action, 5% of Corsairs were lost to enemy action. The Hellcat had more operational losses because it had more carrier based sorties. The P47 had a total of 3662 kills in the ETO, MED and PTO. The Corsair had 2155 kills in the PTO only. The P47 had 697 kills in the PTO. THe Corsair especially early in the war with internal wing tanks had a much longer range than the P47. The Corsair could and did dive bomb, the P47 could not. The Corsair was superior air to air from 25000 feet down where most ACM took place. The P47 began to have better performance above 25000 feet. The Corsair could operate from carriers. The P47 could not. The Corsair could operate from small airfields with bigger combat loads than the P47. To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane. The Corsair, operating from both small forward area landing strips and carriers, carried out the majority of the close air support strikes in the early part of the Korean War. To me, that speaks well for it's versatility.


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## davparlr (Jul 22, 2009)

drgondog said:


> .Until the late model Jugs were designed with internal wing tanks, the range of the Jug with ordnance was significantly less - the Corsair had the edge on the P-47 until the N.. implication - F4U and P-47 load were equal, F4U more agile on deck without load, (or with one), F4U could carry load further until last 5 months of WWII, F4U could escort effectively any USAAF bomber if required including B-29 but 47N would have clear edge at B-29 altitudes.



This is true up until about April, '44. The F4U-1 internal fuel was 341 gallons and the pre-P-47D-25 was 305 gallons. After April, 44, the F4U-1D and on had only 237 gallons internal whereas the P-47D-25 through M had 370 gallons. The P-47N had 550 gallons. So, after April, '44, the P-47D-25 and on, assuming fuel consuption is similar, had better range than any model F4U.


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## davparlr (Jul 22, 2009)

I think that there's no doubt that the F4U was the superior aircraft for the PTO nor do I think there is any doubt that the P-47 was the superior aircraft for the ETO bomber support roles. As for ground support, both were outstanding.


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## drgondog (Jul 22, 2009)

davparlr said:


> This is true up until about April, '44. The F4U-1 internal fuel was 341 gallons and the pre-P-47D-25 was 305 gallons. After April, 44, the F4U-1D and on had only 237 gallons internal whereas the P-47D-25 through M had 370 gallons. The P-47N had 550 gallons. So, after April, '44, the P-47D-25 and on, assuming fuel consuption is similar, had better range than any model F4U.



Dave I agree the data - I forgot the -25 was the first wet wing D. For whatever reason, that did not alter the role of the P-47D re: no deep penetration escort until late summer/early fall 1944 and that was only a few stretch runs to Leipzig area. 

The average long range mission through 1944 for both the F4U-4 and P-47D-25 and newer remained pretty much the same as mid 1944. Differences between the two for Drag and Gross weight at take off had more negative effect on the 47. Empty the F4U was 800+ pounds lighter, with guns, fuel and ammo about 1000 pounds lighter. I don't have comparable drag figures for cruise so my point is speculative.


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## drgondog (Jul 22, 2009)

I just did a quick look at various air to air and air to ground details for the F4U in the PTO and P-47s and P-51s in 8th AF.

Difficult to draw conclusions as the missions and adversary were different -( IMHO tougher air battlesand strafing hazards by far in ETO), but

F4U - 2140+ air victories versus 189 lost in the air and 349 lost to flak
P-51 -3328 air victories versus 326 lost in the air and 570 lost to flak (3212 Ground scores)
P-47 1550 air victories versus 214 lost in the air and 200 lost to flak ( 739 Ground scores)


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## davparlr (Jul 22, 2009)

drgondog said:


> Dave I agree the data - I forgot the -25 was the first wet wing D. For whatever reason, that did not alter the role of the P-47D re: no deep penetration escort until late summer/early fall 1944 and that was only a few stretch runs to Leipzig area.



You were right the first time. The N was the first with wet wings. The -25 and on got additional fuel by increasing the volume of the main tank (space was added at the top of the tank). 



> The average long range mission through 1944 for both the F4U-4 and P-47D-25 and newer remained pretty much the same as mid 1944. Differences between the two for Drag and Gross weight at take off surely had some effect.



Both aircraft had similar clean drag characteristics with the F4U slightly cleaner. Also, both could carry quite a load, and, as such, were quite flexible.


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## drgondog (Jul 22, 2009)

davparlr said:


> You were right the first time. The N was the first with wet wings. The -25 and on got additional fuel by increasing the volume of the main tank (space was added at the top of the tank).
> 
> 
> 
> Both aircraft had similar clean drag characteristics with the F4U slightly cleaner. Also, both could carry quite a load, and, as such, were quite flexible.



Thanks for the correction - I was pretty sure the -25 was not appreciably longer in range but you have an excellent grasp of the published facts.


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## Daviducus2 (Jul 22, 2009)

I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right? The Navy's own apples to apples data established a very large disparity in survivability between the Hellcat and Corsair. 

Speculation - Perhaps others noticed what we now know was a serious problem with the Corsair and attributed it to the wing tanks when it was actually the oil cooling design? Also, I wonder if at least part of the oil cooling system's vulverability (assuming this was the issue) was a function of it being spread over a much larger area than the Hellcat and Thunderbolt which shared a different design.

_As for ground support, both were outstanding._

Yes but in my opinion the P-47 was superior in the air to ground realm because of the data that found that in an apples to apples comparison, *for every 10 Hellcats lost to AA fire, 16 Corsairs were lost*. That's a pretty startling and troubling statistic. I know that if I were a pilot with the choice of pounding ground targets with either a Hellcat or Corsair, I would choose the Hellcat as I want to make it back and my chances of not making it back if I actually take AA fire are 58% higher for the Corsair. 

Assuming the culprit here is the oil cooling design which confers a tremendous advantage to the Hellcat and because the Hellcat and Thunderbolt share the same oil cooling design and there are no known issues (none that I know of) with survivability that are Thunderbolt specific, I would prefer the Thunderbolt for ground support as it would "appear" to have more than a significant edge in survivability over the Corsair.

On a related note, the oil tank on the P-47N was *40 gallons*! That's more than twice the *18 gallon* F4U-4 oil tank. The Hellcat's oil tank was also 18 gallons. One can see how an additional 22 gallons which is 22% more than the Corsair's oil tank to begin with could come in handy if you are leaking oil due to combat damage.


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## davparlr (Jul 22, 2009)

drgondog said:


> Thanks for the correction - I was pretty sure the -25 was not appreciably longer in range but you have an excellent grasp of the published facts.



Books help. America's Hundred-Thousand is a great reference!


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## davparlr (Jul 22, 2009)

Daviducus2 said:


> On a related note, the oil tank on the P-47N was *40 gallons*! That's more than twice the *18 gallon* F4U-4 oil tank. The Hellcat's oil tank was also 18 gallons. One can see how an additional 22 gallons which is 22% more than the Corsair's fuel tank to begin with could come in handy if you are leaking oil due to combat damage.



I suspect the extra oil was needed for the extended range of the N. Those radials really liked oil.


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## Catch22 (Jul 22, 2009)

Daviducus2 said:


> I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right?



No, it's not. They removed the wing tanks from the -1D because by the time it was introduced the vast majority of all operations were from carriers, close to the objectives. They felt they were not needed, and removing them increased performance, notably speed. They were able to do this because of the two hard points on the bottom of the wing roots that were introduced with the -1D, which could be used to carry drop tanks that replaced the wing tanks. The advantage of the drop tanks was, well, you could drop them if needed, so you not only retained the range of the earlier models, but you also got the performance boost.


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## Daviducus2 (Jul 22, 2009)

I confess that Wikipedia was the source of my misunderstanding:

*Additionally, the role of fighter-bombing was a new task for the Corsair and the wing fuel cells proved too vulnerable and were removed.*

Weren't the wing tanks non-self sealing though? That is indicated in the article as well.


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## Catch22 (Jul 22, 2009)

That may very well have been a reason as well, but the main one was the lack of need for range. I'm not sure about the self-sealingness of the tanks, however I haven't really heard of the wing tanks being an issue at all during combat. Come to think of it though, I do remember reading something about pilots purging them before combat.


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## Clay_Allison (Jul 22, 2009)

renrich said:


> The P47 was the original "Ground Hugger" and required a much longer distance to get off the ground than the Corsair. That would have been a serious handicap when operating from short landing strips in the Southwest Pacific with the density altitudes prevelant there. In fact, in the ETO, P47s often took off with less than a full load of ammunition because of weight considerations. The fact is that the Hellcat and Corsair flew about the same number of sorties in the PTO. The Hellcat had 823 combat losses and the Corsair had 538. My book is packed right now but assuming that around 11000 of each type were built in WW2 ( which is close), 7% of Hellcats were lost to enemy action, 5% of Corsairs were lost to enemy action. The Hellcat had more operational losses because it had more carrier based sorties. The P47 had a total of 3662 kills in the ETO, MED and PTO. The Corsair had 2155 kills in the PTO only. The P47 had 697 kills in the PTO. THe Corsair especially early in the war with internal wing tanks had a much longer range than the P47. The Corsair could and did dive bomb, the P47 could not. The Corsair was superior air to air from 25000 feet down where most ACM took place. The P47 began to have better performance above 25000 feet. The Corsair could operate from carriers. The P47 could not. The Corsair could operate from small airfields with bigger combat loads than the P47. To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane. The Corsair, operating from both small forward area landing strips and carriers, carried out the majority of the close air support strikes in the early part of the Korean War. To me, that speaks well for it's versatility.


The P-47 had a poor climb rate initially, this was solved with the switch to "paddle-blade" props. After that they got off the ground well enough and 190 pilots could no longer reliably climb away.


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## drgondog (Jul 22, 2009)

Daviducus2 said:


> I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right? The Navy's own apples to apples data established a very large disparity in survivability between the Hellcat and Corsair.
> 
> Speculation - Perhaps others noticed what we now know was a serious problem with the Corsair and attributed it to the wing tanks when it was actually the oil cooling design? Also, I wonder if at least part of the oil cooling system's vulverability (assuming this was the issue) was a function of it being spread over a much larger area than the Hellcat and Thunderbolt which shared a different design.
> 
> ...



It is simply impossible to draw metric based conclusions between P-47 and F4U in context of survivability.. they didn't have the same mission, weren't flying against same targets, etc.

It is hard enough to compare Mustang to TBolt in 8th AF.


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## Clay_Allison (Jul 22, 2009)

drgondog said:


> It is simply impossible to draw metric based conclusions between P-47 and F4U in context of survivability.. they didn't have the same mission, weren't flying against same targets, etc.
> 
> It is hard enough to compare Mustang to TBolt in 8th AF.


He was drawinig conclusions based on the Hellcat though. He only extrapolated similarities between the Hellcat and the P-47.


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## DAVIDICUS (Jul 22, 2009)

_To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane._

More like a mountain out of a slightly smaller mountain. You are assuming that the Navy knew about the problem, assuming it was the oil cooler as opposed to some other Corsair specific issue. We can see that it didn't occur to the Navy until *mid 1946* that Corsairs were 58% more likely to be losses from AA fire than Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie." In fact, even if you don't control for these variables, Corsairs were still dropping from the sky at far higher rates than Hellcats.

At any rate, if we chalk it up to some other issue specific to the Corsair, that apparently escaped the Navy's notice too.

I for one do not find it hard to believe that the fog of ongoing war would obscure the vulnerability of the Corsair. Especially when probably no one was looking at loss rates under comparable circumstances or probably comparative loss rates at all. After all, both aircraft were very sturdy, shared the R-2800 engine and were similarly unbelievably successful against their Japanese opponents.


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## JoeB (Jul 22, 2009)

Catch22 said:


> That may very well have been a reason as well, but the main one was the lack of need for range. I'm not sure about the self-sealingness of the tanks, however I haven't really heard of the wing tanks being an issue at all during combat. Come to think of it though, I do remember reading something about pilots purging them before combat.


The F4U-1's wing tanks were non-self sealing. So, carrying wing fuel (124 gal) and a 175 gal center line drop tank in F4U-1 was roughly equivalent to carrying 2*150 gal drop tanks in an F4U-1D or -4. Either way it was viewed as highly desirable to burn off or drop unprotected fuel before entering air combat (though it wasn't always the case, USN fighters sometimes retained their drop tanks in air combat). And, either way the full load meant more than 1/2 the fuel was unprotected (230-odd gal protected internal tank), and again assuming a plan to use only protected fuel in combat, the radius was determined by the capacity of the protected internal tank to fight and get home. Extra unprotected fuel just allowed more pre-combat patrol time at that max radius.

The F4U-1 arrangement allowed the flexibility to enter combat with unprotected fuel, if necessary, without extra drag. The -1D arrangement had more flexibility to get rid of the fuel.

Re: F4U and F6F ground fire vulnerability and mountain or mole hill, it is what it is. It's as statistically clear as it ever would be that the F4U was significantly more vulnerable. How important that was would depend a lot on what the key missions were. Early in WWII it wouldn't have been very important at all. By 1945 it was somewhat important. In a war where carrier planes conducted constant air strikes with essentially no air or anti-ship threat for months on end (see: Korea) it was a relatively quite serious issue. It was too late to bring the F6F back, but it almost surely would have been a better a/c for the F4U's mission in Korea. Again see 1945 stats, F4U's did *not* carry more ordnance per sortie from carriers than F6F's, not in actual practice. And in Korea, typically, high value targets weren't being smashed by a few decisive strikes. The realistic goal was harassing the enemy, gradually inflict casualties and damage it was hoped, and only occasionally, perhaps, scoring any really satisfying success. The heavy losses of beat up old F4U-4's were not such a big deal, they were going to the boneyard soon anyway, but the losses of pilots was more of an issue, even from a completely non-sentimental POV of trying to re-expand naval aviation for the Cold War. To this was added the F4U's inherently higher accident rate, especially in the more difficult operating conditions typically faced by carrier a/c in Korea compared to the Pacific War, more especially in the winter time.

But as shown by all these debates here, it wasn't hard at all to miss the fact of greater F4U vulnerability before the stats were accumulated (or in these threads, before people are fully aware of them and just how apples to apples they are). Even afterward naval air thinking emphasized dashing hell-for-leather wars like WWII. And even in the actual conditions of Korea once apparent, leadership simply had a blind spot about air crew losses that didn't make a lot of sense compared to the actual results achieved. It's hard to explain certain decisions in KW any other way (goes for the USAF as well).

Joe


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## Daviducus2 (Jul 22, 2009)

Seriously though, the ability to keep facts from interfering with preconceived fantasy is almost beyond belief. 
.
.
.

[Edited for content.]


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## DAVIDICUS (Jul 22, 2009)

The oil tank on the P-47D, all models, was 28.7 gallons - 59% more than the 18 gallon tanks in the Hellcat and Corsair.


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## Clay_Allison (Jul 23, 2009)

I think some people hear desperately want to believe that the Corsair was not more vulnerable to gunfire than the Hellcat (and by implication, the Jug) because the Corsair looks cool and they like it.


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## renrich (Jul 23, 2009)

The P47N, according to "America's Hundred Thousand," restored the P47's POOR climb rate, no doubt because of the additional weight. The early Corsair's wing tanks were not self sealing but had a CO2 purge system. (must have had a huge carbon footprint) That additional fuel was very useful in the early going in the Solomons on land based missions. In "Whistling Death'" by Boone Guyton, there is an interesting story about the CO2 purge system in the Corsair. I urge all who have any interest in the Corsair to get a copy of that book. Guyton was the chief test pilot on the Corsair program and was the fellow who crashed the prototype on a golf course. The proof is in the pudding, the Corsair was judged in the fighter meet as the best fighter bomber, Rex Barber( AAF fighter pilot) stated that if the US had to build one fighter it would be the Corsair and the Navy declared the F4U1D superior to the Hellcat as a fighter and fighter bomber and the Hellcat was replaced. No doubt the P51 was more vulnerable to enemy fire than the P47. That did not keep it from being THE premier AAF fighter.


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## DAVIDICUS (Jul 24, 2009)

I must confess that I do not have Francis Dean's book but I understand that it is excellent. I don't know the context of the restoration of poor climb rate comment in the book. Certainly a plane with an internal fuel capacity of 570 gallons like the P-47N will be hampered in performance over a plane with an internal fuel capacity of just 237 gallons like the F4U-4. That represents a difference in fuel weight of over 2,000lbs. Imagine how the Corsair would climb with a 2,000lb bomb load. I suspect that with a "D" load of fuel, which is still 133 gallons more than than the F4U-4, the "N"'s performance would be a lot closer to the "M" as the empty "N" weighed only 556 lbs more than the empty "M" and had a larger wing area.

The P-47N and F4U-4, as is quite obvious, were machines designed for very different roles. Per design, that extra fuel the "N" carried was necessary to get the Thunderbolt to where it needed to be to destroy enemy aircraft attacking long range bombers. So we have two aircraft with enormous disparities in internal fuel capacity being compared to each other with full internal fuel loads. And we have one with accessories for carrier use and one without. One with accessories for high altitude performance and the other without.

With respect to Corsair v. Thunderbolt, I think that for ground attack, the astonishing vulnerability of the Corsair simply made it unsuitable for ground attack. I think that for low and medium altitude air combat, the Corsair was quite excellent. In think that for high altitude escort work, 25,000ft and above, the Corsair was again unsuitable. Conversely, I think the Thunderbolt was quite excellent for ground attack and higher altitude escort work.

_The proof is in the pudding, the Corsair was judged in the fighter meet as the best fighter bomber_

The fighter meet? Was that before or after May 1946? Is it just me or wasn't this issue just addressed above? If a decision is made and afterwords data comes to light that calls into question assumptions upon which the decision was based, do we simply look at the decision that was made and exclaim that the decision wouldn't have been made it it were the wrong decision? Wait ... don't answer that.

Did the vote casters know of the glass jaw issue? Do you think that survivability might be a huge factor in evaluating combat effectiveness of a fighter utilized in a low level bomber role? Here's a hint. Even in light of the far superior performance of the Corsair over the Hellcat, the USN declared the Hellcat "slightly superior to the F4U in combat, apparently chiefly because of its greater ability to survive damage." (See NACS, page 58) Also note that this finding was reached with the benefit of data on 22,000 sorties including a well controlled apples to apples comparison between the two aircraft.

_[T]he Navy declared the F4U1D superior to the Hellcat as a fighter and fighter bomber and the Hellcat was replaced._

Please tell me that you didn't actually write that ... after you wrote about the proof pudding and after it was previously explained to you that the NACS report was published mid 1946.

Lastly, me thinks that you read far too much purity into the reasons behind production decisions on the part of the military.


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## Clay_Allison (Jul 24, 2009)

DAVIDICUS said:


> I must confess that I do not have Francis Dean's book but I understand that it is excellent. I don't know the context of the restoration of poor climb rate comment in the book. Certainly a plane with an internal fuel capacity of 570 gallons like the P-47N will be hampered in performance over a plane with an internal fuel capacity of just 237 gallons like the F4U-4. That represents a difference in fuel weight of over 2,000lbs. Imagine how the Corsair would climb with a 2,000lb bomb load. I suspect that with a "D" load of fuel, which is still 133 gallons more than than the F4U-4, the "N"'s performance would be a lot closer to the "M" as the empty "N" weighed only 556 lbs more than the empty "M" and had a larger wing area.
> 
> The P-47N and F4U-4, as is quite obvious, were machines designed for very different roles. Per design, that extra fuel the "N" carried was necessary to get the Thunderbolt to where it needed to be to destroy enemy aircraft attacking long range bombers. So we have two aircraft with enormous disparities in internal fuel capacity being compared to each other with full internal fuel loads. And we have one with accessories for carrier use and one without. One with accessories for high altitude performance and the other without.
> 
> ...


Bear in mind that a P-47 on a short range mission would have no more fuel on board than the mission called for.


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## Focke Wulf Meister (Jul 24, 2009)

I would take the P-47. Love the Jug.

Here are some interesting stats on the two planes:

According to Chance Vought, Report No. 7289 dated 21 May 1947 the F4U-4 had a high speed @ airplane critical altitude (29,900 feet) of 383 knots. Its time to climb to 10,000 feet was 3.9 seconds. Time to 20,000 feet was 8.0 seconds. 

Initial rate of climb at sea level (feet/min. combat power) was 4,360 f/m. Service ceiling was 40,850 feet. Endurance at high speed at 25,000 feet was 1 hour. Endurance at 60% speed at 21,500 feet was 4.1 hours. Maximum endurance @ 7,000 feet was 6.8 hours. Maximum range @ 7,000 feet was 960 nautical miles. 

According to a Republic report dated 15 April 1945, the P-47N-5-RE had a high speed @ airplane critical altitude (32,000 feet) was 467 mph. Time to climb to 15,000 feet was 6.2 seconds. Time to climb to 20,000 was 11.6 seconds under military power. 

Service ceiling for the N was 40,400 feet. Its maximum range @ 7,000 feet was 740 nautical miles @ cruising speed. 

FLIGHT TEST DIVISION MEMORANDUM
REPORT SERIAL NO. TSFTE-2012
17 September 1946

FLIGHT TESTS OF THE P-47N AIRPLANE
AAF NO. 44-88406

Summary:

The P-47 N airplane has performance and handling characteristics very similar to the early P-47 airplanes, but due to heavier weights caused by greater fuel capacity, performance is lower when using equal power settings. The rate of roll is slower, due to the weight being farther from the longitudinal axis of the airplane.

Control forces are good, but as in the earlier model P-47 airplanes large changes in trim are necessary for a change in airspeed.


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## marshall (Jul 24, 2009)

Focke Wulf Meister said:


> Its time to climb to 10,000 feet was 3.9 seconds. Time to 20,000 feet was 8.0 seconds.
> 
> Time to climb to 15,000 feet was 6.2 seconds. Time to climb to 20,000 was 11.6 seconds under military power.




Man those are some well climbing airplanes...


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## Catch22 (Jul 24, 2009)

DAVIDICUS said:


> With respect to Corsair v. Thunderbolt, I think that for ground attack, *the astonishing vulnerability of the Corsair simply made it unsuitable for ground attack.* I think that for low and medium altitude air combat, the Corsair was quite excellent. In think that for high altitude escort work, 25,000ft and above, the Corsair was again unsuitable. Conversely, I think the Thunderbolt was quite excellent for ground attack and higher altitude escort work.



If you look at the actual history, you'll see that that simply is not the case. The Corsair was an excellent ground attack plane, as it showed in both WWII and Korea. It had its vulnerabilities yes, but to call it unsuitable for ground attack is non-sense. The US Navy and the French Navy sure disagreed with you, as the last Corsair built for the US was completed in 1952, ten years after the first one came out, while the French F4U-7 was last built in 1953, and it was a ground attack version. The Corsairs only real role post-war was ground attack, and I'm certain the Navy wouldn't have chosen it if it was unsuitable for that role.


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## Daviducus2 (Jul 24, 2009)

I give up.


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## R Leonard (Jul 24, 2009)

Focke Wulf Meister said:


> I would take the P-47. Love the Jug.
> 
> According to Chance Vought, Report No. 7289 dated 21 May 1947 the F4U-4 had a high speed @ airplane critical altitude (29,900 feet) of 383 knots. Its time to climb to 10,000 feet was 3.9 seconds. Time to 20,000 feet was 8.0 seconds.
> 
> ...



I believe you mean minutes, not seconds. At the Cleveland Air races in November 1946 LCDR Butch Davenport, in an F8F-1, set a piston climb to time record from a dead stop to 10000 feet in 97 seconds; that stood, I believe, into the late 1970's. Neither the P-47 not the F4U could climb faster than an F8F.


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## JoeB (Jul 24, 2009)

Catch22 said:


> If you look at the actual history, you'll see that that simply is not the case. The Corsair was an excellent ground attack plane, as it showed in both WWII and Korea. It had its vulnerabilities yes, but to call it unsuitable for ground attack is non-sense. The US Navy and the French Navy sure disagreed with you, as the last Corsair built for the US was completed in 1952, ten years after the first one came out, while the French F4U-7 was last built in 1953, and it was a ground attack version. The Corsairs only real role post-war was ground attack, and I'm certain the Navy wouldn't have chosen it if it was unsuitable for that role.


It is tempting to give up, but let's go over the simple facts and logic one more time:

-the USN's immediate postwar attitude toward prop fighters was still mainly driven by a perceived air to air role, only naturally. And the F4U-4 was a definitely superior performer to F6F-5.
-therefore there is simply no logic in claiming they wouldn't have chosen the F4U as main prop fighter if it was relatively vulnerable in ground attack missions, because that wasn't necessarily *foreseen* as the main mission, especially not month after month strike against low value targets with almost no air threat and anyway the true air-air role turned over to jets. The Korea scenario was simply not the scenario under with F6F was shunted to reserves immediately postwar.
-the stats proving the F4U it was substantially more vulnerable are very hard to get people here (who presumably view themselves as intelligent and reasonable) to fully digest and pay attention to, though they are simple and convincing to any objective eye. It shows that people can have preconceptions, and difficulty overcoming them in the face of new data. There's no reason to categorically rule out similar gaps in logical thinking as contributing to Navy decisions, though as in the point above that sort of bad decision making wouldn't be necessary to explain the choice. The main reason it's very plausible to say the Navy chose the wrong prop fighter for Korea in 1945, is that they weren't thinking about the Korean War scenario in 1945. 

And as the Korean War went on, the naval air services as a whole top to bottom certainly did not agree that the F4U was a fully satisfactory ground attack plane. At the pilot level there was bitterness about the general situation of losses v tactics and modest results achieved, but there are a number of contemporary references to the F4U's specific problems with high loss rate. One was quoted above, a point is made of it in Heinl's "Victory at High Tide" about the Inchon campaign is another that occurs to me offhand, fairly frequently referred to in accounts of F4U ops in Korea.

On versions, almost all of the F4U's used in daylight strike missions in Korea were -4/4B's from wartime contracts. Relatively few 'straight' F4U-5's were built, and that a/c was viewed positively as a dog for the Korea strike mission because of bugs which had crept into the design, and its general optimization for a different (high altitude) mission. Only specialist F4U-5's (-5N and -5P) were commonly used in Korea, among truly postwar F4U's. And the vulnerability of the basic F4U was the reason for the redesigned oil system, and greater armor in the AU. The F4U-7 was basically the AU with the F4U-4's engine, so the French never flew the more vulnerable versions of the F4U, only ex USMC AU's, then F4U-7's.

Joe


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## Butters (Jul 24, 2009)

I'm speculating, but it seems to me that the USN's late-war decision to end Hellcat production and go with the Corsair as the standard long-range carrier fighter-bomber was based on the facts that the Bearcat was ready to take on the role of fleet defense interceptor, and Douglas had demonstrated that the Skyraider was going to be a superb attack bomber. The F6F could not match the air to air performance of the late model Corsairs, nor would it be as capable in attack role as was the AD-1. Add in the production of the F7F, and Grumman seems kind of stretched. So, so long, Hellcat...It just wasn't needed any longer.

Jus' guessin'...

JL


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## DAVIDICUS (Jul 24, 2009)

Interesting how the Navy's Air Combat Statistics and numerous informed accounts just happen to sing in harmony. Quite a coincidence indeed.


From Ron Stout -

"I do recall that the MC [Marine Corps] asked that a F4U version be built for ground attack *with the oil cooler relocated to be more immune from ground fire* and some additional armor plate. As I remember it was redesignated the AU and also was purchased by the French and designated the F4U-7."

KUNSAN AIR BASE: How It Was - VMF(N)-513 (1951-1954) Page 6 of 9



From F4U Corsair Units of the Korean War, Page 16

1st Lieutenant Lance "Bud" Yount of VMF-323-

I felt the thud from the round [20mm] as it hit. Suddenly there was a puff of smoke in the cockpit, and I watched my oil pressure drop down to 15psi - normal was approximately 80psi. I yelled out that I'd been hit, and was turning to head south. One of the pilots in my division pulled up alongside me and said that he was going to stay with me, and that I should try to fly the aircraft back to the ship. I dropped a few degrees of flap as he flew under my tail searching for the oil leak. Naturally, with the sharp decrease in oil pressure,* I was sure my oil cooler had been hit - it was in a very vulnerable spot*.



From Crimson Sky, The Air Battle For Korea, page 67

It was the cruelest kind of fluke. Somewhere on the frozen, snow covered ground below, a Chinese soldier lay on his back, his white quilted uniform making him virtually invisible from the air. As the four Corsairs passed overhead with the throaty roar of their Pratt Whitney engines echoing off the winter landscape, the soldier raised his rifle and pulled the trigger. His comrades did the same, throwing up a hail of bullets around the four blue planes. 

What are the chances a rifleman could hit such a speeding target? And even if the tiny .30 caliber bullet did connect with a Corsair, what damage could it possibly do? The F4U-4B was not only heavily armed but armored to protect both pilot and plane from ground fire. 

*Yet one round hit home, probably hitting the Corsair's Achilles Heel, the oil cooler. ... Less that three minutes after he had been hit, his engine seized and he lost power so fast that he had no chance to make a run for the coast.*



From Brassey's Ar Combat Reader, Page 174

That decision was coming home to haunt the Corsair pilots. *Their airplanes would be hit by nothing more serious than a single rifle bullet, and their engines would seize when all the engine oil leaked from the oil cooler*.



From A Revolutionary War: Korea and the Transformation of the Postwar World, Page 138 (Research presented at the Fifteenth Military History Symposium, held at the United States Air force Academy, 14-16 October 1992)

*The Corsair, an air cooled radial engine aircraft, might have been expected to have a higher survivability than the Air Force's liquid cooled (and hence vulnerable) F-51 Mustang. In fact, insufficient oil cooler and engine protection rendered the Corsair just as susceptible as the Mustang to ground fire.*
.
.
.


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## R Leonard (Jul 24, 2009)

Butters said:


> Jus' guessin'...
> JL



Your speculation is correct. VT/VB function combined in the AD, F8F for point defense fighter, F4U as strike fighter.

Rich


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## Catch22 (Jul 25, 2009)

I DO understand the vulnerability, my point was that the F4U was far from unsuitable for ground attack. Yes, it was more vulnerable than other planes, but if it was unsuited it probably wouldn't have been used as extensively. I will however admit that I was mistaken when I said that they chose it for its usefulness in the ground attack role over the F6F.

_If you look at the actual history, you'll see that that simply is not the case. The Corsair was an excellent ground attack plane, as it showed in both WWII and Korea. *It had its vulnerabilities yes*, but to call it unsuitable for ground attack is non-sense. The US Navy and the French Navy sure disagreed with you, as the last Corsair built for the US was completed in 1952, ten years after the first one came out, while the French F4U-7 was last built in 1953, and it was a ground attack version. The Corsairs only real role post-war was ground attack, and I'm certain the Navy wouldn't have chosen it if it was unsuitable for that role._

I certainly acknowledged the vulnerabilities in that post! I was not saying anything to the contrary.


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## DAVIDICUS (Jul 25, 2009)

_*ut if it was unsuited it probably wouldn't have been used as extensively.*_*

Perhaps I should have said "comparatively unsuitable." You go to war with the hardware you have irrespective of the soundness of the decisions that brought you to where you are. No one is saying that the U.S. should not have used its full capacity to wage war on the enemy by using less than all available assets. And if you decide in hindsight that it's acceptable to absorb a much higher loss rate for similar performance in ordinance delivery, then that comfort level will necessarily lead you to conclude that the Corsair was not only suitable but performed very well in the air to ground role against defended targets. There is no established rule of analysis that forces you to take into account the loss side of the ledger. Losses of aircraft and losses of pilots. 

Lets say we have two contemporary aircraft that appear to perform similarly in the air to ground role. If it came to your attention that one of those aircraft was 58% more likely to be lost from anti-aircraft fire than the other when actually hit by anti-aircraft fire during the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the both aircraft received "about the same number of hits per sortie," would you classify the aircraft that's 58% more likely not to return, leave its pilot dead, behind enemy lines or just somewhere in the water or on the ground as unsuitable in that role? 

Put differently, if you could reasonably anticipate losing 16 of one type of aircraft for every 10 of the other type under the apples to apples comparison above, would that move you to declare one of those aircraft as unsuitable? What about if you are a pilot? Do you think you might summarily conclude that one of those aircraft is simply unsuitable in that roll?

There is a certain elasticity to language that often results in disagreements over characterizations. Can we agree that if you were a pilot and were expected to pound defended targets and had a choice between flying a Corsair or Hellcat and knew about the 16:10 loss ratio that you would refuse to go near a Corsair with a 10 foot pole?

We are not talking about an established 12:10 loss ratio here which might lead you to conclude that one appeared to have an edge. A 16:10 loss ratio is a staggering disparity and a frightening reality if you are a pilot.

I know that the P-51 also performed admirably in air to ground operations. In my opinion, if the same defended target could be reached with P-47's for the delivery of the same ordinance, the P-51 would be unsuitable for such operations. I base that opinion on the mere assumption that far fewer Mustangs would return. Now perhaps fewer Mustangs would be hit to begin with. I don't know. Admittedly, I am taking license in engaging in some speculation. With respect to the Hellcat vs. Corsair, we don't need to base such an opinion on assumption and speculation. We have well controlled data establishing clear, bright conclusions.

As I indicated previously, assuming the Corsair's oil cooling design is the culprit responsible for the very large disparity in survivability, in my opinion the Thunderbolt would probably have the same or similar advantage over the Corsair that the Hellcat enjoyed. Just an opinion. To the extent that my opinion is that the Corsair was not well suited to attacking defended targets in relation to the Hellcat, I also hold that opinion about the Corsair in relation to the Thunderbolt. You are, of course, free to refuse to extend the comparison beyond the Hellcat due to the lack of well controlled data between the Corsair and Thunderbolt.*


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## drgondog (Jul 25, 2009)

Davidicus - as long as you are delving into statistics - what are your thoughts regarding why 8th AF Mustangs destroyed 50% more aircraft on the ground per Mustang lost to flak than the 8th AF Jugs?

 Ground scores
A/c -- dest--lost
P-47 739 200 ----------> loss rate/ac destroyed = .27 or around 1 for 4
P-51 3212 570 ----------> loss rate/ac destroyed = .17 or around 1 for 6
P-38 161 109 ---------------------------------------> = .67 or around 2 for 3

I KNOW the Mustang coolant system was more vulnerable to damage - but the mission was the same for both types of fighters at the same times. Only wild card factor was 51 and 38 hadrange over the 47.
PS - the P-38 by these statistics was by far the most vulnerable - with two engines
.


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## Catch22 (Jul 25, 2009)

DAVIDICUS: 

Yes, I can agree with you there. And I agree that the P-47 was probably better for ground operations in regards to durability. The one thing I didn't agree with is that the Corsair was unsuitable for ground operations, but that's cleared up now.


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## DAVIDICUS (Jul 25, 2009)

By "mission was the same" do we mean the same type of mission or that both P-47's and P-51's were flying literally against the same targets, at the same time and facing the same defensive fire? Were both types taking about the same number of hits per sortie? Were P-47's more likely to be hit in such missions? Were P-47's more likely to be delivering bombs? Does that matter?

What is the "same time" period that we are taking about? 

How do we count "aircraft destroyed on the ground"? Do we mean aircraft that appeared to have been destroyed on the ground as claimed by US fighter pilots flying above? Were any of those "destroyed" aircraft not really destroyed but just damaged? Was it more likely for P-51 or P-47 drivers to actually destroy an aircraft on the ground as opposed to it just appearing to have been destroyed and claiming it to be destroyed? Did the eight gun battery of the P-47's generally inflict more damage per strafing run thus making it more likely that aircraft that appeared destroyed were actually destroyed? 

Are we also relying on German data on aircraft destroyed on the ground in a given location at a given time and then trying to match that to US records of claims of aircraft destroyed on the ground at those same locations? Does this pose any problems? 

Did more P-51's in a given mission fly against such targets than P-47's? Were larger numbers of attacking aircraft able to neutralize anti aircraft measures to a greater extent than their increased numbers provided additional targets for anti-aircraft gunners? Did larger numbers of attacking aircraft result in multiple claims on the same destroyed aircraft due to more passes on the same grounded aircraft? Were P-51's more likely to re-visit the same targets and thus possibly re-destroy and reclaim some of the same aircraft previously hit and totaled?

How do targets of opportunity fit in where US claims of aircraft destroyed on the ground can't be reliably matched to specific locations for which German data is available? Were P-51's more likely to engage targets of opportunity pursuant to their roving around on longer missions that afforded more targets deeper into enemy territory? Did P-47's have access to those same targets? Do we discount US claims for which we don't have corroborating German data? Would this be more likely to affect P-51 or P-47 claim totals? 

It sounds like there are too many "wild cards" and I suspect that you, with your wealth of knowledge, can not only dispel some of the issues I have raised above, but can identify additional issues that would interfere in any evaluation based on the limited parameters you have constructed. I do know, however, that at the Report of Joint Fighter Conference, NAS Patuxent River, MD 16-23 October 1944, the following discussion ensued:

Lieutenant Gavin: "In connection with this discussion by the aircraft manufacturers, on the preference of an engine, I think it would be interesting if we could have comment from some of the Army people here as to relative vulnerability of the liquid-cooled and air-cooled installations based on their experience in Europe."

Colonel Garman: "I can only speak for the African Theater and only for a particular type of operation. The P-38 was used at low level on many occasions and we found that it was quite vulnerable to ground fire - any type of ground fire, even small-arms fire. But the other airplanes also experienced that same ground fire and the radial engines brought the planes home. You can't lay down any hard and fast rule and say the inline is no good at low altitude as far as ground fire is concerned. It all depends on the operation entirely."

Lieutenant Colonel Tyler: "*We have data which shows that in the entire European theater the P-47 is much better able to take punishment and return after any sort of mission - either ground attack or any mission which incurs damage. That may be due to the P-47 airplane or due to the air-cooled feature. We don't know which but it certainly can take it better than the other plane types*."

It would be interesting to obtain that "data."
.
.
.


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## JoeB (Jul 25, 2009)

Yes, unsuitable, it's always a relative term. It's just wordy to say 'relatively unsuitable'. Of course the F4U, and F-51 (as designated by the time of the Korean War), could deliver a reasonable load of ordnance on the target and had good endurance over a target at the prevailing ranges (in either case compared to jets); and both returned their pilots from the vast majority of missions. But both had distinctly elevated loss rates in the ground strike role compared to more or less contemporary a/c in their air services which had been phased out, or close enough to be being phased out that it was decided not to substitute them in Korea, but I say that was in retrospect a mistake in both cases. The F6F and F-47 would have been the better a/c for that war, especially the F6F. 

There's no reasonable argument they would have achieved less against targets because not only were the ordnance loads similar in practice, but the main mission in reality was harassing the enemy, whose targets were generally hard to detect and easy for him to repair with masses of cheap labor. And the total of pilots lost would have been dozens fewer, applying the comparative loss rates from WWII*. That's especially clear in the F6F/F4U case where the loss rate comparison in ground strike missions in WWII is so well documented, and where the F6F was also the more operationally suitable airplane (distinctly lower carrier accident rate). In F-47/F-51 case the longer runways required by F-47's would have been a countervailing factor in the F-51's favor in some circumstances.

*the USN lost 130 F4U-4/4B's in Korean War carrier ops to enemy action (2 to enemy a/c, almost all the rest to AA), plus 104 in accidents; the USMC lost 56 (1 to enemy a/c) and 55 -4/4B and 1 and 1 -5's in carrier ops ; 91 and 50 -4/4B's and 9 and 17 -5 's in land based ops, total of 514 day strike F4U's. That doesn't include recon or night fighter F4U's, nor AU's. Apply the differences in loss rate to AA and carrier accidents in 1945 ops and that would be a savings on the order of 150 a/c if F6F's had been used instead, and dozens of pilots would have avoided death or captivity. 

Joe


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## DAVIDICUS (Jul 25, 2009)

Remember also that when a plane went down, the ensuing rescue operation risked aditional lives and hardware as well. I have a book that mentions Corsair and Skyraider pilots' awareness of the vulnerability of the Corsair issue in that context.

I will drag it out when I get back from being out of town.


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## drgondog (Jul 25, 2009)

DAVIDICUS said:


> By "mission was the same" do we mean the same type of mission or that both P-47's and P-51's were flying literally against the same targets, at the same time and facing the same defensive fire? Were both types taking about the same number of hits per sortie? Were P-47's more likely to be hit in such missions? Were P-47's more likely to be delivering bombs? Does that matter?
> 
> *8th AF doctrine had all fighter groups flying escort (penetration, target, withdrawal, fighter bomber sweep, sweep, etc.*
> 
> ...



All agreed - I posed to you 'how do you reconcile the lower performance ofP-47 stafing credits to strafing losses vs the P-51 and you threw up a blizzard of anecdotal disussions and questions?

What is your answer - base it on facts not desire to skew it to one conclusion or another based on personal preference.


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## DAVIDICUS (Jul 25, 2009)

_I posed to you 'how do you reconcile the lower performance of P-47 stafing credits to strafing losses vs the P-51 and you threw up a blizzard of anecdotal disussions and questions?_

You said: 

_*what are your thoughts* regarding why 8th AF Mustangs destroyed 50% more aircraft on the ground per Mustang lost to flak than the 8th AF Jugs?_

I didn't attempt a reconciliation of the stats you provided. I responded with my thoughts about a naked stat. 

As I also said, "I suspect that you, with your wealth of knowledge, can not only dispel some of the issues I have raised above, but can identify additional issues that would interfere in any evaluation based on the limited parameters you have constructed."

I would venture that you know a great deal about the facts behind that data and I have the distinct impression that you think you can reconcile the data which you provided. You posed the stat. Not me. You posed the question about thoughts and then reconciliation. Not me. 

Here's an idea. Why why don't you answer your own question. I for one would like to know the answer as well and as I have indicated, I do not have an answer for you.


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## drgondog (Jul 26, 2009)

DAVIDICUS said:


> _I posed to you 'how do you reconcile the lower performance of P-47 stafing credits to strafing losses vs the P-51 and you threw up a blizzard of anecdotal disussions and questions?_
> 
> You said:
> 
> ...



Fair enough D. 

Simply stated is that one may not draw statistical conclusions as there is not enough data regarding flak defenses at airfields in different locations (but one may assume airfields with Me 262s ALWAYS had very strong defenses - mostly out of Jug range). The 355th lost a lot of Mustangs in the Augsburg, Leipheim, Oberpfaffenhofenetc airfields around Munich.

The only way, in my opinion, would to be build up a body of facts for P-47s and P-51's attacking the same airfields over a significant period of time, and at essentially the same time frame. I would like to see that in the USN reports also.

8th AF Mustangs were strafing airfields all over Germany, in addition to the same ones strafed by Jugs (Western Germany, Holland, France), as well as strafing in Czechoslovakia and Poland - so the Mustang coverage was approximately four times the area reachable by the P-47 until the very late P-47D-25 and M.

We can point out how tough a Jug was and pitiful the Mustang was to ground fire - but the airfield strafing statistics don't seem to support the conclusions. I am equally circumspect about F6F and F4U statistics and drawing conclusion that the oil cooler was the culprit. I can agree it was more vulnerable, but someone has to do some serious presentation before I conclude that any definite percentage of F4U losses were due primarily to hits to the very small area represented - relative to say the pilot or the fuel tank or a even a fuel line. 

Other questions raised already lead back to doctrine - were the F4U's more prone to be in the dirt with F6F flying higher runs? Were the targets attacked essentially and statistically the same from a defense capability standpoint? 

I respect the USN analysis, just don't have enough data to come to same conclusions?


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## DAVIDICUS (Jul 26, 2009)

_The only way, in my opinion, would to be build up a body of facts for P-47s and P-51's attacking the same airfields over a significant period of time, and at essentially the same time frame.* I would like to see that in the USN reports also.*_

NACS report indicated that Corsairs were 58% more likely to be losses from AA fire than Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."

_Other questions raised already lead back to doctrine - were the F4U's more prone to be in the dirt with F6F flying higher runs? Were the targets attacked essentially and statistically the same from a defense capability standpoint?_

You raised that question earlier in post #280

_Ditto the F4U vs F6F. I suppose the USN may have had some sense of the mission profiles but it would be interesting for example to look at losses at Okinawa where the AA was heavy and the fighters were at very low level. Were more F6F's flying CAP for the fleet while the Corsairs were getting singed on the deck?_

JoeB addressed that exact point in post #282

*The figures are damaged suffered and losses per sortie encountering AA. So it should basically correct for mission profile differences. It wouldn't include pure air to air sorties, nor total milk run ground attack sorties. And 1945 carrier sorties only, so cuts out a lot USMC operations on Okinawa (which I doubt was heaviest AA loss environment anyway, that would probably have been going after airfields in Japan, as it had similarly been in ETO). And as mentioned already stats are given for both a/c damaged and lost, and rate of damage was similar, undercutting any assumption of a hidden difference in average mission profile or tactics between the two types on 'sorties encountering AA'. The main difference was % of a/c hit by AA which didn't make it back, which was much higher for the F4U, and that's actually the succinct point made in the notes to the NASC table, as quoted above.*

Obviously JoeB is more knowledgeable than I with respect to the reasons for your continuing doubt. If he has not already tired of this dead horse beating exercise, perhaps he will re-address your continuing doubt.


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## drgondog (Jul 26, 2009)

I respect JoeB's opinions. I respect the USN reports. I respect the individual pilot accounts.

What I question, only because I have not seen the data from which the statistics were derived, is the collection and allocation process to view the combat reports, gather the staistically quantifiable data surrounding the variables being examined, see what was tossed and what was included... then see what data was sampling process reliable for 'oil cooler' losses between the two ships.

So I remain skeptical of the process of assigning oil cooler as the prime determinant, much less assign a percentage to it. I can intuitively agree it was a point of vulnerability, just not prepared to accept assign a reliable percentage cause of failure to the F4U oil cooler.

Having said THAT, I am more comfortable with a conclusion that for the same mission profile in the same period, for the aircraft losses when flak was a factor - the the F6F was less vulnearble per sortie than the F4U. That would represent a fact gathering/validation process less subject to error than digging out primary system failure cause

THAT conclusion is less of a reach than assigning "oil Cooler' as a statistically measurable cause of failure. My mind would change if I was told that there was a high enough population of pilots downed that were able to report to another pilot that his oil pressure had dropped after being hit... and that the data was included in the vulnerabilty report as a footnote.

Summary - I agree JoeB's conclusions that the USN was able to reduce the comparison between F6F to F4U to the primary variable of ships lost to number of ships damage by flak to number of sorties in which flak was encountered to point one or more ships were damaged. I GET THIS. I ACCEPT THIS. I AM NOT DEBATING THIS (I am not shouting - just want you to understand what I am debating versus what I agree)

What I have expressed the most 'doubt about' is the conclusion a.) that the Oild Cooler was as statistically provable root cause as the primary reason for much higher loss rate for F4U, and b.) your presumption that the P-47 was less vulnerable than the F4U without bringing the data and the assumptions and the analysis to the table?

Back to the Thread - there is no data to support a conclusion that the F4U was more or less vulnerable to flak than a P-47N.

Ditto for a similar conclusion between F4U and Mustang. I say this ONLY because I am not aware of a survey to compare the two a/c for Korean War ops. Ditto for P-47 vs P-51.

I apologize for distressing you with my continuing doubt bhave many other flaws we haven't addressed yet.


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## JoeB (Jul 26, 2009)

drgondog said:


> Ditto for a similar conclusion between F4U and Mustang. I say this ONLY because I am not aware of a survey to compare the two a/c for Korean War ops. Ditto for P-47 vs P-51.


There are no comprehensive statistics that I know of for the naval services which plot loss rates per sortie for the whole Korean War. The loss stats I quoted above is from the last (July '53) of the Navy's monthly reports of losses and losses to date in Korean ops by type, but it doesn't give sorties. The USN did a number of 'interim reports' of Korean ops that have loss rates for sub periods for USN a/c. Also USMC unit period records in Korea were very detailed, much more than USN. Sortie loss rates could be calculated bottom up from those reports. USAF (5th AF) also had a series of monthly reports that gave both losses and sorties, and total losses and sorties are quoted as well.

The problem is, a raw comparison of F4U and F-51 sorties loss rates *would* in general be apples and oranges. Several of the doubts and challenges to the F4U v F6F comparison, which are not really valid in that case, *would* be valid objections in an F4U v F-51 Korea comparison. Such as most of the combined USN and USMC F4U losses in Korea were from carriers, and comparing carrier to land based losses penalizes the carrier plane, not only for accidents but combat losses where a land based plane would have been able to land. Then, even comparing USMC land based to USAF, the possibility of different mission profiles and tactics is a much more real concern. In F4U v F6F case we know both a/c were *hit* about as often, further reassuring us of similar mission profiles in the carrier only, 'encountered AA' only, sorties in the 1945 stats. In Korea AFAIK there are no stats for rate of a/c *hit*.

The USN and USMC specifically changed tactics as the KW went on to raise the altitude of ordnance release and cut down some of the losses. So it's very possible that in any given period USAF and USMC tactics actually did differ, and the Marines wouldn't necessarily have been the more aggressive at all times.

But with all that said, from what I've seen F4U and F-51 loss rates in Korea were very broadly similar, and F-51's were ~.5% per combat sortie. Those were of course lower rates than typical in WWII. But they were mainly viewed as high in both services compared to much lower loss rates of jets on strike missions (for example F-80's rate=.15%, and most of its missions were ground strike for most of the war*), and v the AD's lower loss rate in case of the naval services.

*Navy jet types too; in the "Bridges at Toko-ri" (book version) one small caliber bullet knocks out a twin engine F2H, and it could theoretically have happened, but in general jets were harder to hit because of their speed, and also tougher if hit.

Joe


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## DAVIDICUS (Jul 26, 2009)

_What I have expressed the most 'doubt about' is the conclusion ... and b.) your presumption that the P-47 was less vulnerable than the F4U without bringing the data and the assumptions and the analysis to the table?

Back to the Thread - there is no data to support a conclusion that the F4U was more or less vulnerable to flak than a P-47N._

Agree that there is no "data" to support a conclusion that the F4U was more or less vulnerable to flak than a P-47N. The only "data" I have brought to the table, so to speak, is that the F4U was far more vulnerable than the Hellcat. I have lots of presumptions and opinions drgndog. On this forum we all throw around speculation, presumption, extrapolation, etc. when comparing aircraft (something that goes on an awful lot here) as there is very little hard data that affords apples to apples comparisons for which we can assign conclusions grounded in established fact. Are you now the forum's policeman who will be issuing citations every time someone throws out an opinion based on an assumption for which there is no hard data available? 

As for the "conclusion" you seem to think I have issued and are foisting upon others, let's review exactly what I have said.


Post #309

*Assuming the culprit here is the oil cooling design* which confers a tremendous advantage to the Hellcat and because the Hellcat and Thunderbolt share the same oil cooling design and there are no known issues (*none that I know of*) with survivability that are Thunderbolt specific, *I would prefer* the Thunderbolt for ground support as *it would "appear"* to have more than a significant edge in survivability over the Corsair.

Post #324

With respect to Corsair v. Thunderbolt,* I think* that for ground attack, the astonishing vulnerability of the Corsair simply made it unsuitable for ground attack.* I think* that for low and medium altitude air combat, the Corsair was quite excellent. *I think* that for high altitude escort work, 25,000ft and above, the Corsair was again unsuitable. Conversely, *I think* the Thunderbolt was quite excellent for ground attack and higher altitude escort work.

Post #336

I know that the P-51 also performed admirably in air to ground operations.* In my opinion*, if the same defended target could be reached with P-47's for the delivery of the same ordinance, the P-51 would be unsuitable for such operations. *I base that opinion on the mere assumption* that far fewer Mustangs would return. Now perhaps fewer Mustangs would be hit to begin with. *I don't know. Admittedly, I am taking license in engaging in some speculation*. With respect to the Hellcat vs. Corsair, we don't need to base such an opinion on assumption and speculation. We have well controlled data establishing clear, bright conclusions.

As I indicated previously,* assuming the Corsair's oil cooling design is the culprit *responsible for the very large disparity in survivability,* in my opinion* the Thunderbolt would probably have the same or similar advantage over the Corsair that the Hellcat enjoyed. *Just an opinion.* To the extent that *my opinion* is that the Corsair was not well suited to attacking defended targets in relation to the Hellcat, I also hold *that opinion* about the Corsair in relation to the Thunderbolt. *You are, of course, free to refuse to extend the comparison beyond the Hellcat due to the lack of well controlled data between the Corsair and Thunderbolt.*


Notice the last sentence of post #336. I stand by the above statements which are appropriately qualified and explained and frankly do not care if they are not good enough for you. 
.
.
.


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## drgondog (Jul 26, 2009)

DAVIDICUS said:


> _W
> 
> 
> Notice the last sentence of post #336. I stand by the above statements which are appropriately qualified and explained and frankly do not care if they are not good enough for you.
> ...


_

works for me._


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## drgondog (Jul 26, 2009)

JoeB said:


> There are no comprehensive statistics that I know of for the naval services which plot loss rates per sortie for the whole Korean War. The loss stats I quoted above is from the last (July '53) of the Navy's monthly reports of losses and losses to date in Korean ops by type, but it doesn't give sorties. The USN did a number of 'interim reports' of Korean ops that have loss rates for sub periods for USN a/c. Also USMC unit period records in Korea were very detailed, much more than USN. Sortie loss rates could be calculated bottom up from those reports. USAF (5th AF) also had a series of monthly reports that gave both losses and sorties, and total losses and sorties are quoted as well.
> 
> The problem is, a raw comparison of F4U and F-51 sorties loss rates *would* in general be apples and oranges. Several of the doubts and challenges to the F4U v F6F comparison, which are not really valid in that case, *would* be valid objections in an F4U v F-51 Korea comparison. Such as most of the combined USN and USMC F4U losses in Korea were from carriers, and comparing carrier to land based losses penalizes the carrier plane, not only for accidents but combat losses where a land based plane would have been able to land. Then, even comparing USMC land based to USAF, the possibility of different mission profiles and tactics is a much more real concern. In F4U v F6F case we know both a/c were *hit* about as often, further reassuring us of similar mission profiles in the carrier only, 'encountered AA' only, sorties in the 1945 stats. In Korea AFAIK there are no stats for rate of a/c *hit*.
> 
> ...



Thanks Joe -


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## renrich (Jul 27, 2009)

I printed the Naval Aviation Combat Statistics. 158 pages of fine print, I think, and have been studying. I have acquired eyestrain, but the material is most interesting. It does appear to me that the authors were trying to bolster the case for carrier aviation during that postwar period that the argument between the Navy and the Air Force was going on. It is unfortunate that the record is not as complete as far as the early part of the war, 1942-43, is concerned as later. Table 19, Aerial Combat data for the entire war contained some information that the author's failed to highlight. Carrier based F6Fs flew 6582 sorties where EA were engaged. There were 245 F6Fs shot down and 419 damaged. The F4Us flew 1042 of the same type of sorties and lost 34 and had 31 damaged. The damage/loss ratio is much higher for the Hellcat than the Corsair, while the EA destroyed per loss is fairly even, 20.2 for the Hellcat and 17.0 fro the Corsair. In land based sorties where EA were engaged, the F4U flew 2258 sorties with 155 Corsairs shot down and 231 damaged whereas the F6F only flew 393 action sorties with 25 losses and 38 damaged so that damage to loss ratio is more even. Does that info indicate the Corsair was less likely to incur damage in an aerial encounter? Also am reading a recent book about the Marianas Battle and a couple of interesting points were related. One was that a Coronado pilot, of all things, fancied himself as a fighter pilot and on two separate occasions shot down a Betty snooper. A second was that the Japanese Army AC copied the French in that the throttle was pulled to you to increase power whereas the IJN AC used the US and British method of pushing the throttle to increase power. An interesting observation in the book; " Next up was Commander Bill Dean's Fighting 2, whose eight Hellcats claimed nine Zekes and three Jills that broke off from the main formation. The Hornet pilots found they could not stay with the speedy attackers in a high speed descent, though two Cowpens divisions tried without success." Does that situation indicate perhaps why the Navy came to value the Corsair over the Hellcat? Anyway this book, by Barrett Tillman, makes it obvious that even as early as June 1944 the skill and training of most of the Japanese pilots was sadly lacking.


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## Josh64 (Sep 27, 2009)

The P-47N was only in combat briefly from early 1945, to compare it to the Corsair which was in combat since 1943, as to which one was better is pretty hard if not impossible to do. Both were excellent divers, but in this category it really doesn't matter because Japanese planes couldn't dive fast at all without coming apart, a cessna 150 could probably outdive a Zero!. If the Thunderbolt N had the same combat history as the Corsair then you could compare them accurately, but this unfortunately isn't the case.


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## Jank (Sep 27, 2009)

The F4U-4 did not see combat until the end of 1944. The P-47N was delivered to front line squadrons by the end of 1944 but I don't think it saw combat until the beginning of 1945.


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## Josh64 (Sep 27, 2009)

Jank said:


> The F4U-4 did not see combat until the end of 1944. The P-47N was delivered to front line squadrons by the end of 1944 but I don't think it saw combat until the beginning of 1945.



Oh F4U-4, didn't catch that. Thanks


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## wwii:)aircraft (Oct 13, 2009)

Both the F4U-4 and P-47N were excellent aircraft.
The P-47N was probably superior in rate of role, armament, dive (remember that the 47n was heavier than the 47d), and was more durable. And it was faster above 25,000ft (maximum speed of 448mph at 25,000ft)
The F4U-4 was overall more maneuverable, was better in a climb and was faster below 20,000ft.

Both are also tied in the fighter-bomber/close-support role, just depends on what you want.
If you want more bombs, the corsair (up to 5,200lbs of bombs)
If you want more guns, the 47; 8 x .50cal machine guns (M2), and I think even 8 x M3 .50cal machine guns (not sure)


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## renrich (Oct 13, 2009)

The F4U, all models had one of the best rates of roll of any WW2 fighter and It got better with each model. I doubt seriously if the P47N had a superior rate of roll over the F4U4.


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## renrich (Oct 16, 2009)

Regarding the roll performance of the P47, this is a quote from my "Bible" "America's Hundred Thousand," by Dean, page 302, '
" Nobody raved about the aileron performance of P47s, though data from the P47C-1 showed a peak roll rate of about 85 degrees per second (a 4.2 second full roll) at 250 mph IAS with a 50 pound pilot force on the stick. Other information, for a P47D-30 or D-40 indicated a peak of about 60 degrees per second ( a 6 second roll) at around 220 mph IAS using a stick force of 30 pounds. Roll rate dropped to half that value at 400 mph IAS."


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## syscom3 (Oct 16, 2009)

renrich said:


> Regarding the roll performance of the P47, this is a quote from my "Bible" "America's Hundred Thousand," by Dean, page 302, '
> " Nobody raved about the aileron performance of P47s, though data from the P47C-1 showed a peak roll rate of about 85 degrees per second (a 4.2 second full roll) at 250 mph IAS with a 50 pound pilot force on the stick. Other information, for a P47D-30 or D-40 indicated a peak of about 60 degrees per second ( a 6 second roll) at around 220 mph IAS using a stick force of 30 pounds. Roll rate dropped to half that value at 400 mph IAS."



At what altitude?

The P47's had fast roll rates way up high.


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## renrich (Oct 16, 2009)

The paragraph quoted is from the section on each aircraft called Handling Qualities and Characteristics. No mention of altitude. In the graphs that show the different roll rates there is no provision for altitude. Just roll rate limited by a stick force of 50 pounds compared to speed. Why would an aircraft have a better roll rate at high altiude than at lower altitudes? The limiting factor on roll rate seems to be the efficiency of the ailerons and the strength of the pilot and his ability to deflect the ailerons. The more efficient the aileron, the less strength needed to deflect them. As speed rises more force is required. That is why that at 400 mph the roll rate dropped to 30 degrees per second using a stick force of 30 pounds. The reason the A6M at speeds much above 200 mph began to lose it's maneuverability was that too much pilot force was needed to deflect the ailerons. I wonder if, at very high altitudes, since the air is thinner, the P47's ailerons became easier to deflect and more efficient?


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## renrich (Oct 16, 2009)

On the Williams site there is a USAAF evaluation of the P47N which states that the roll rate of the P47N is worse than the earlier models of the P47. Makes sense to me because of the greater wing span and the weight of the fuel in the wings.


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## DAVIDICUS (Oct 16, 2009)

Renrich, I have seen that too and don't know what to make of it.

Snorts (a past forum member who was apparently banned) recounted his father's experiences flying both the D and N with respect to roll and commented that the N rolled better than the D. He also posted about his father's experiences in mock dogfights with Corsairs. 

See Posts starting with #241

http://www.ww2aircraft.net/forum/aviation/p-47n-thunderbolt-vs-f4u-4-corsair-superior-738-17.html

I have also read in numerous places (as I know you have too) that the N rolled better than the D such as the following:

The XP-47N took to the air for the first time on July 22, 1944. Test comparisons were made with a P-47D-30-RE throughout the early portion of the evaluation period. *Much to everyone’s surprise, the XP-47N, with its greater wingspan and higher weight actually proved to have better roll performance than the D model. At 250 mph TAS, the N attained a maximum roll rate just over 100 degrees/second. The P-47D-30-RE could manage but 85 degrees/second at the same speed. At higher speeds, the N widened the gap further.* In mock combat with a P-47D-25-RE, the new fighter proved to be notably superior in every category of performance. In short, the XP-47 waxed the venerable D model regardless of who was piloting the older fighter. The new wing was part of this newfound dogfighting ability, however, the more powerful C series engine played a role too. The additional horsepower allowed the N to retain its energy better than the older Thunderbolt. Perhaps the greatest performance increase was in maximum speed. Though not as fast as the stunning P-47M, the heavier N was fully 40 mph faster than the P-47D-25-RE and could generate speeds 30 mph greater than its principal rival, the Mustang. Scorching along at 467 mph @ 32,000 ft., the N could not be caught by any fighter in regular service with any air force on earth with the single exception of its M model sibling. This combination of wing and engine had pushed the N model up to the top rank of the superlative prop driven fighters then in existence.

The testing program included determining the maximum range of the fighter. This was done with various combinations of fuel loads and external drop tanks. Ultimately, a test flight was made from Farmingdale to Eglin Field in Florida. The XP-47N took off with two 315 gallon drop tanks hanging from the under-wing hardpoints. Usable fuel in these tanks totaled 600 gallons. Added to the internal fuel load, the N eased off the runway with 1,170 gallons of fuel (usable). At a gross weight of 20,166 lbs., the Thunderbolt headed south in company with a P-47D chase plane. Arriving off the coast, east of Elgin in 3 hours, 44 minutes, the external tanks were dropped. Another P-47D, already waiting at Elgin, took on the N in a mock dogfight that lasted for twenty minutes. The throttle was advanced to military power for 15 minutes of this time, with an additional five minutes in the War Emergency Power (WEP) detent. After these fun and games were concluded the N was turned around and flown back towards Farmingdale. Heavy weather over Long Island caused the plane to divert to Woodbine, New Jersey. Having flown 1,980 miles, total fuel usage was measured at 1,057.5 gallons. There was still more than 112 gallons of usable fuel remaining in the main fuselage tank, enough for another 330 miles @ 1,700 rpm in auto-lean. The XP-47N was now the king of long-range single engine fighters (the all time leader of long range escorts was the P-38L-1-LO, which could claim a combat radius of nearly 1,500 miles under ideal conditions).

Sources:

Dean, Francis, “America’s Hundred Thousand: U.S. Production Fighters of WWII.”
Bodie, Warren M., “Republic’s P-47 Thunderbolt: Seversky to Victory.”
Bodie, Warren M., “The Lockheed P-38 Lightning.”
Boyne, Walter, “Clash of Wings: WWII in the Air.”
Ferguson Pascalis, “Protect and Avenge: The 49th Fighter Group in WWII.”
Freeman, Roger, “Thunderbolt, A History of the Republic P-47.”
Freeman, Roger, “The Mighty Eighth.”
Hammel, Eric, “Air War Europa.”
Johnson, Robert, “Thunderbolt!”
Scutts, Jerry, “P-47 Thunderbolt Aces of the 8th Air Force.”

Seversky Aircraft and Republic Aviation

It would certainly be interesting to get some data on roll rates for the P-47D and P-47N. The P-47N had a larger wing area, squared wing tips and larger ailerons as well.

It would appear that squaring the wings can have a dramatic effect.







I'm trying to find data and information on roll rates. I see tactical trials by the RAF in 1943 regarding mock combat between the P-47C other aircraft. 

Against Spitfire Mk. IX

25. Manoeuvrability – The good aileron control gives the P-47 an excellent rate of roll even at high speeds, and during mock combats it was considered to roll as well as, if not better than the Spitfire at about 30,000 feet. At lower altitudes there is nothing to choose between them. 

Against Typhoon IB

30. Manoeuvrability – The P-47C was considered far superior in rate of roll to the Typhoon, and at 20,000 feet in turning circles proved itself slightly better. 

Against Mustang X

35. Manoeuvrability – The rate of roll of the P-47 is considerably better than that of the Mustang, which cannot follow sudden changes in direction. In rate of turn, however, the two aircraft are practically identical. 


P-47 Tactical Trials


There are widespread assertions across the web that the squared wing tips gave the P-47N an improved roll rate over the P-47D. It would be nice to see some data that would enable a comparison.

I would also add that a website that Renrich has cited to in the past which is devoted to proving that the F4U-4 was the best fighter bomber of the war states the following about the F4U-4:

*The F4U also rolled well. When rolling in conjunction with powerplant torque, in other words, rolling left, it was among the very fastest rolling fighters of the war. In the inventory of American fighters, only the P-47N rolled faster, and only by 6 degrees/second.*

http://home.att.net/~historyzone/F4U-4.html

I'm looking at that USAAF evaluation of the P47N. Odd. It is an evaluation of a P-47N that is apparently different than earlier P-47N's. It mentions:

F. Maneuverability and Aerobatics.

Maneuverability and aerobatic characteristics are similar to earlier P-47’s in the clean configuration. *With wing tip tanks filled the rate of roll and radius of turn of the P-47N is poor.* No aerobatics were performed at the high gross weights (wing and belly tanks), but the rate of roll was slow for this condition. 

This is odd. Wing tip tanks? The wing tanks were located next to the fuselage.

IV Conclusion

1. Due to the large quantity of fuel it can carry, the P-47N is a good long range fighter-bomber. Although the performance is not too good at high gross weights, it improves as the external fuel is used and* by the time the target area is reached it compares favorably to earlier P-47N’s. *

This seems to indicate that it's performance was different than earlier P-47N's which apparently had better performance. ??? These tests were performed in 1946. Was this a version of the "N" that had wing tip tanks?


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## DAVIDICUS (Oct 17, 2009)

I just came across another interesting account of the vulnerability issue that was discussed earlier starting at Post #263 on this thread.

http://www.ww2aircraft.net/forum/aviation/p-47n-thunderbolt-vs-f4u-4-corsair-superior-738-18.html



*From Grant Goodell. He was Skip’s, Babis’s, and my skipper in VA-741 in the sixties. A great guy, a solid stick and an excellent leader.

I flew both airplanes: about 2500 hours in the F4U 4 including a combat tour in Korea off the Antietam1951-52; about 800 hours in the P 47D as a test pilot. As a prop air superiority fighter I would take the F4U over the P47, more nimble and great rate of climb.

Capt. Brown, RN who flew almost every thing and had more than 2000 carrier landing didn’t like the F4U because of high stick forces at very high speeds. You could always pick a Corsair pilot out of the crowd at the bar because of the size of his right bicep. The F6F had a better kill ratio than the F4U because the Hellcat met mostly low time Japanese Army and Navy pilots in 1944 whose favorite defensive maneuver was a Luffberry Circle.

On the other hand the P 47 far outclassed the F4U as a fighter-bomber. The Jug was an absolute terror, carried about the same bomb and rocket load, but had 8 (EIGHT) 50 cal guns. In addition the F4U suffered from having an oil cooler radiator in each leading edge wing root inboard of the gull (check the pics). Any ground fire small arms or expended brass from a plane ahead could penetrate that radiator and in 30 to 40 seconds you had lost oil pressure.

The Navy lost more than 360 F4Us in Korea. more than any other type by far, because of this vulnerability. We lost eight F4Us in our squadron and 2 pilots, both to enemy ground fire. Vought never fixed the problem. On the other hand the AF kept sending P-51s to do ground attack and N Korea was carpeted by 51 aluminum and Rolls 12 cylinder inlines built, as I recall, by Packard. Where were the Jugs?

Grant Goodell*

http://www.neptunuslex.com/2009/09/01/f-4u-vs-p-51/


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## renrich (Oct 18, 2009)

Eric Brown, RN was a highly biased observer and absolutely did not like the Corsair. His book, "Duels in the Sky," is filled with incongruent statements about many WW2 aircraft. I and many others on this forum discount much of what he has to say. Ironically, I have read that Eric Brown and Marion Carl were friends and spent a lot of time together. Brown has very little to say good about the Corsair and Carl seemed to think it was a great airplane and, of course, had a lot of experience with it. Oddly I have accounts of pilots flying the Corsair that extoll the virtues of the Corsair's ailerons at high speeds.


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## DAVIDICUS (Oct 18, 2009)

_Oddly I have accounts of pilots flying the Corsair that extoll the virtues of the Corsair's ailerons at high speeds._

I don't think it's odd at all. The Corsair is known for being an excellent roller. The P-47 was also known for being an excellent roller.

You said that on the Williams site there is a USAAF evaluation of the P47N which states that the roll rate of the P47N is worse than the earlier models of the P47. I was just pointing out that that account appears to stand by itself as pilot accounts and statements across the web state the opposite.

I have read the testing you are referring to and think I may understand what was meant.

The site says:

*IV Conclusion

1. Due to the large quantity of fuel it can carry, the P-47N is a good long range fighter-bomber. Although the performance is not too good at high gross weights, it improves as the external fuel is used and by the time the target area is reached it compares favorably to earlier P-47N’s. 
*

Do you see how in this 1946 test its performance was adjudged worse than"earlier P-47N's"? And it also referred to the test plane having "wing tip tanks." Earlier versions of the P-47N, at least those that saw combat, did not have wing tip tanks. I think that when it stated earlier in the test that it rolled slower than earlier "P-47''s", it meant earlier P-47N's just as the above excerpt referred to the test plane performing worse than earlier P-47N's. If the "N" was inadvertently left off and we have all seen lots of typos in these 1940's documents, there is harmonization with literally all other statements and references on the matter.

Just something to think about.

And what do you make of that account that the P-47N rolled faster by 6 degrees over the F4U-4? I know that in the past you have referred to the assertions in that website in support of your arguments.

It's really unfortunate that we don't have source docs on roll rates for may of the planes we discuss which gives rise to all these speculations to begin with.

Lastly, I only posted that last piece that mentioned Brown for an additional reference to the vulnerability issue that plagued the Corsair and the Eric Brown reference did not even touch on that. The Eric Brown reference was confined to:

*Capt. Brown, RN who flew almost every thing and had more than 2000 carrier landing didn’t like the F4U because of high stick forces at very high speeds. You could always pick a Corsair pilot out of the crowd at the bar because of the size of his right bicep. The F6F had a better kill ratio than the F4U because the Hellcat met mostly low time Japanese Army and Navy pilots in 1944 whose favorite defensive maneuver was a Luffberry Circle.*

Do you have any information that counters the vulnerability issue? I think it's reasonable to conclude that it was the oil coolers as opposed to some other system or characteristic but strictly speaking, while we know that the Corsair was about 60% more likely to go down than the Hellcat after actually suffering AA combat damage in a well controlled apples to apples analysis involving some 22,000 sorties, we only have opinions from pilots and others that it was the oli cooling system which was different than the Hellcat and Thunderbolt which shared an identical design except that the Thunderbolt carried significantly more oil.


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## renrich (Oct 18, 2009)

I do not believe that the Corsair was 60 % more vulnerable than the Hellcat to AA fire. It may have been more vulnerable but not to that extent. For my argument on that issue, please go to post # 1233 in the Best WW2 Aircraft. Intuitively, to me, a small target like the oil cooler can't be responsible for that big a difference. I don't believe that the statistical study is valid because there are too many variables. As far as ailerons and high speeds are concerned the F4U1D was ranked second in the Joint Fighter Conference for ailerons at 350 mph, well ahead of the P47D and just behind the P51D. In Dean's book, he states that very high roll rates( about 120 degrees per second at 350 mph IAS) have been claimed for the Corsair and nothing has been found to belie those statements, but no firm data has been found either. That does not sound like stiff ailerons at high speed. Richard Linnekin stated that F4U4 was a" stable airplane with reasonable, not objectionable, control forces." He said it had better control harmony than either the F6F or F8F and that he finally became a decent air to air gunner in the F4U because of it's good control harmony. He also stated that the F4U did not have the "right rudder and right rudder trim deficiencies of the Hellcat." The Corsair could be a problem on takeoff or landing if the 6 degrees right rudder and 6 degrees right wing down aileron trim was not used. As mentioned before, in Dean's book, the P47 was not praised for it's rolling ability. Just to show how valid all this information is, in Bob Johnson's book, "Thunderbolt" he states that the P47 was a much better roller than a Spitfire and he used that rolling ability in mock dogfights with the Spitfire. Go figure.


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## DAVIDICUS (Oct 18, 2009)

_I do not believe that the Corsair was 60 % more vulnerable than the Hellcat to AA fire. It may have been more vulnerable but not to that extent._

Yes, well I did say "about 60%." The correct figure is actually 58%.

_I don't believe that the statistical study is valid because there are too many variables._

Perhaps you can identify them as you are the one attacking the Naval Air Combat Statistics, and explain why they favored the Hellcat such that the enormous disparity of 58% arose and why they were not washed out by the enormous pool of data collected. To recap, the Navy collected data on 22,000 sorties and found that Corsairs were 58% more likely to be losses from AA fire than Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."

And also please offer your thoughts on the coincidence of the following accounts and why, also coincidentally, there does not appear to be a wealth of such accounts with respect to the Hellcat and Thunderbolt which had oil cooling systems that were not just identical but very different than the Corsair's.


From Ron Stout -

"I do recall that the MC [Marine Corps] asked that a F4U version be built for ground attack* with the oil cooler relocated to be more immune from ground fire* and some additional armor plate. As I remember it was redesignated the AU and also was purchased by the French and designated the F4U-7."
KUNSAN AIR BASE: How It Was - VMF(N)-513 (1951-1954) Page 6 of 9


From Crimson Sky, The Air Battle For Korea, page 67

It was the cruelest kind of fluke. Somewhere on the frozen, snow covered ground below, a Chinese soldier lay on his back, his white quilted uniform making him virtually invisible from the air. As the four Corsairs passed overhead with the throaty roar of their Pratt Whitney engines echoing off the winter landscape, the soldier raised his rifle and pulled the trigger. His comrades did the same, throwing up a hail of bullets around the four blue planes.

What are the chances a rifleman could hit such a speeding target? And even if the tiny .30 caliber bullet did connect with a Corsair, what damage could it possibly do? The F4U-4B was not only heavily armed but armored to protect both pilot and plane from ground fire.

*Yet one round hit home, probably hitting the Corsair's Achilles Heel, the oil cooler. ... Less that three minutes after he had been hit, his engine seized and he lost power so fast that he had no chance to make a run for the coast.*


From F4U Corsair Units of the Korean War, Page 16

1st Lieutenant Lance "Bud" Yount of VMF-323-

I felt the thud from the round [20mm] as it hit. Suddenly there was a puff of smoke in the cockpit, and I watched my oil pressure drop down to 15psi - normal was approximately 80psi. I yelled out that I'd been hit, and was turning to head south. One of the pilots in my division pulled up alongside me and said that he was going to stay with me, and that I should try to fly the aircraft back to the ship. I dropped a few degrees of flap as he flew under my tail searching for the oil leak. Naturally, with the sharp decrease in oil pressure,* I was sure my oil cooler had been hit - it was in a very vulnerable spot.*


From Brassey's Ar Combat Reader, Page 174

That decision was coming home to haunt the Corsair pilots. *Their airplanes would be hit by nothing more serious than a single rifle bullet, and their engines would seize when all the engine oil leaked from the oil cooler.*


From A Revolutionary War: Korea and the Transformation of the Postwar World, Page 138 (Research presented at the Fifteenth Military History Symposium, held at the United States Air force Academy, 14-16 October 1992)

*The Corsair, an air cooled radial engine aircraft, might have been expected to have a higher survivability than the Air Force's liquid cooled (and hence vulnerable) F-51 Mustang. In fact, insufficient oil cooler and engine protection rendered the Corsair just as susceptible as the Mustang to ground fire.*


From Grant Goodell

*In addition the F4U suffered from having an oil cooler radiator in each leading edge wing root inboard of the gull (check the pics). Any ground fire small arms or expended brass from a plane ahead could penetrate that radiator and in 30 to 40 seconds you had lost oil pressure.

The Navy lost more than 360 F4Us in Korea. more than any other type by far, because of this vulnerability. We lost eight F4Us in our squadron and 2 pilots, both to enemy ground fire. Vought never fixed the problem. On the other hand the AF kept sending P-51s to do ground attack and N Korea was carpeted by 51 aluminum and Rolls 12 cylinder inlines built, as I recall, by Packard.* Where were the Jugs?
F4-U vs P-51 « Neptunus Lex


I don't wish to rehash this whole discussion again. I can't imagine offering anything other than has already been analyzed and discussed at length on the subject of the Corsair's enormous vulnerability to damage from ground fire. I will add the following observation though: *We have more controlled data to support the enormous disparity in vulnerability between the Corsair and Hellcat than to support any disparity existing at all between the Mustang and Thunderbolt.* I also can't help but think that if the disparity between the Corsair and Hellcat were reversed such that the Hellcat were established to be 58% more vulnerable to ground fire, that you would just add that statistic as another feather in the Corsair's cap.

For other forum members, see the discussion beginning at Post #263:
*http://www.ww2aircraft.net/forum/aviation/p-47n-thunderbolt-vs-f4u-4-corsair-superior-738-18.html*

I don't know what to make of all the roll rate discrepancies. As I already indicated, it would be nice to have some data for both aircraft so that we are not piecing together speculations. I find it interesting what Robert Johnson said about outrolling the Spitfire as it may have some support in the P-47C tactical trials against the Spitfire Mk. 9. (We don't know which version Spitfire he was sparring with.)


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## davparlr (Oct 19, 2009)

Very interesting site on Jack Payne, P-47 pilot. Almost seems unreal, but there are pictures . Maybe this has been referenced before.

Me Fahdda


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## renrich (Oct 19, 2009)

I believe we do have data on rates of roll of US fighters. Page 602 in Dean has an article and graph from NACA TR868 and Perkins and Hage(whatever that is) Also as far as roll rate is concerned, on the Williams site there is a comparison between FW190(that was supposed to be a premier roller) and F4U1 and F6F3. It stated that the FW rolled with great ease, EQUAL to the F4U and better than the F6F. 

On the oil cooler issue, I am merely giving an opinion and am not trying to win points in any debate. Also trying a little common sense and I believe there is at least one other member on this site,(whose opinion I highly value) who shares my opinion about the so called statistical study and the 58% number. Too many variables to be valid. A for instance, to me, is the majority of all air to ground missions in F4Us were flown by Marine pilots. Do Marines press attacks closer than USN pilots? I suspect that they do. I can't prove it! In the Naval Aviation Combat Statistics there is mention of the fact that the vast majority of air to ground missions in the Phillipines were flown by F4Us and they did good work.

We do have some facts to go by. Hellcats dropped 6503 tons of munitions in the PTO and had 553 losses to AA. Corsairs dropped more than twice the number of munitions, 15621 tons, and had 349 AA losses. I know, I know, the Corsairs were dropping bombs on islands with few Japs in residence and only a few bathing beauties on the beach. Still those numbers seem significant to me. How many Corsair bombs were dropped on bathing beauties and how many on mad Japs in the Phillipines where the Hellcat was absent. To me, in 64051 combat sorties flown by F4Us, to lose only 349 to AA and 189 to EA does not indicate a lot of vulnerability. The Hellcat lost a good many more in almost the same number of sorties against probably less competent Japanese pilots. We also have the fact that the USN picked the F4U1D over the F6F5. There are lies, damn lies and statistics. Facts, common sense and intuition go a long way with me. It is common sense that the oil cooler in the Hellcat or P47 was less vulnerable to ground fire or air to air fire than that of the F4U. 58% or whatever in that range I don't believe.


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## DAVIDICUS (Oct 19, 2009)

_I believe we do have data on rates of roll of US fighters. Page 602 in Dean has an article and graph from NACA TR868 and Perkins and Hage(whatever that is) _

I don't have Dean's book. So what is the roll rate between the P-47N and F4U-4? This discussion arose regarding those two planes.

_Too many variables to be valid. A for instance, to me, is the majority of all air to ground missions in F4Us were flown by Marine pilots. Do Marines press attacks closer than USN pilots? I suspect that they do. I can't prove it!_

We already addressed this earlier in the thread. If this thesis had merit, then we would not see "about the same number of hits per sortie" as between the two aircraft. JoeB stated the following:

"The figures are damaged suffered and losses per sortie encountering AA. So it should basically correct for mission profile differences. It wouldn't include pure air to air sorties, nor total milk run ground attack sorties. And 1945 carrier sorties only, so cuts out a lot USMC operations on Okinawa (which I doubt was heaviest AA loss environment anyway, that would probably have been going after airfields in Japan, as it had similarly been in ETO). And as mentioned already stats are given for both a/c damaged and lost, and rate of damage was similar, *undercutting any assumption of a hidden difference in* average mission profile or *tactics between the two types on 'sorties encountering AA'*. The main difference was % of a/c hit by AA which didn't make it back, which was much higher for the F4U, and that's actually the succinct point made in the notes to the NASC table, as quoted above."

I also gave you another startling stat earlier in the thread. For all carrier operations, for the entire war, Navy pilots (just Navy pilots) lost Corsairs in combat at a rate *66% higher *than Navy Pilots (just Navy pilots) lost Hellcats.

_We do have some facts to go by. Hellcats dropped 6503 tons of munitions in the PTO and had 553 losses to AA. Corsairs dropped more than twice the number of munitions, 15621 tons, and had 349 AA losses. I know, I know, the Corsairs were dropping bombs on islands with few Japs in residence and only a few bathing beauties on the beach. Still those numbers seem significant to me._

So if I understand you correctly, you want to ditch the Naval Air Combat Statistics controlled data for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" because there are too many uncontrolled for variables and instead adopt the metrics you cite above as evidence regarding Corsair vulnerability to AA fire?

_Facts, common sense and intuition go a long way with me. _

On the first two, you and I will just have to agree to disagree.


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## renrich (Oct 19, 2009)

Because the graph is small the following is subject to error caused by the width of the pencil lead but the F4U1D has only a limited range of performance in the graph and it is a straight line at around 45 degrees ranging from a roll rate of 75 degrees per second at 240 mph IAS to 90 degrees per second at 290 mph IAS. The P47C-1 has a roll rate ranging upward from 59 degrees per second at 160 mph IAS to 82 degrees per second at 240 mph, where it begins to drop rather rapidly at about a 30 degree angle where for example it's roll rate at 350 mph IAS is only about 72 degrees per second. Contrast that with reported roll rates for the Corsair at 350 mph IAS of 120 degrees per second. Apparently, according to Dean, a roll rate resulting in a four second 360 degree roll was good performance for a WW2 fighter.
Going back to the accursed oil cooler, on page 80 of the NACS report there is a table showing, among other things the % lost of planes hit by AA fire in the whole war. This would be a much larger sample and would to me be a much more accurate indicator of the relative vulnerability of the various types and would also seem to fit well with common sense judgment of relative vulnerability based on looking at the location of the oil coolers IMO. The authors declare that this table distorts the relationships between planes and that is probably true when looking at AA losses per 100 action sorties, planes hit per 100 attacks AA present and AA losses per 100 attacks AA present. But I don't believe it distorts the relationship between types when looking at % lost of planes hit. A hit is a hit whether in 1943, 44 or 45 and whether flown by USN or Marine pilots. The table shows that 24 % of Hellcats that were hit were lost. 29 % of Corsairs hit were lost and 27% of FMs hit were lost. My opinion is that those ratios, intuitively reflect the difference in vulnerability caused probably by the location of the oil cooler. I don't believe that difference rises to the 58% level. Perhaps more interesting is that only 12 % of SBDs hit were lost and 27% of the SB2Cs hit were lost. Another interesting point subject to our learned interpretation is that the SBDs and Corsairs were more likely to have been used in land based operations where as the Hellcats were more likely to have been carrier based. A factor to be considered also is whether the aircraft shot down by AA were going against AA fire from ships or from ground based AA. The report does not seem to make that distinction. Beyond all this I am absolutely good with agreeing to disagree.

Regarding the relative effectiveness and vulnerability in combat, A Hellcat was lost to EA action for every 25.83 combat sorties whereas a Corsair was lost to EA action for every 17.46 combat sorties which seems to favor the Hellcat, but the Corsair was in action in the Solomons in February 1943 against some still well trained IJN pilots. The Hellcat did not go into action until August of that year and by then the Japanese pilot erosion had become well advanced. The fact still remains that the Navy decided the Corsair was more useful than the Hellcat and there are countless comparisons between performance of the two and the Corsair is always superior.


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## DAVIDICUS (Oct 19, 2009)

_On page 80 of the NACS report there is a table showing, among other things the % lost of planes hit by AA fire in the whole war. This would be a much larger sample and would to me be a much more accurate indicator of the relative vulnerability of the various types and would also seem to fit well with common sense judgment of relative vulnerability based on looking at the location of the oil coolers IMO._

The whole war? And this would satisfy your concern about too many unaccounted for variables such that you would accept it over the Naval Air Combat Statistics data on what you see as an insufficient 22,000 sorties for just carrier operations between the Corsair and Hellcat for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie"?

Please. That's like pouring gasoline on a fire out of concern that the fire might get larger. The more uncontrolled variables the better if it will whittle that 58% down ... right?

_The fact still remains that the Navy decided the Corsair was more useful than the Hellcat and there are countless comparisons between performance of the two and the Corsair is always superior._

Did it decide this before or after the Navy's analysis in the NACS? It would appear that the problem was severe enough that even with that wide margin of performance superiority, the Navy, in mid 1946, concluded the following from an analysis of 22,000 sorties of carrier operations between the Corsair and Hellcat for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."

 From Naval Aviation Combat Statistics, WWII

Page 58:

*Thus comparisons are valid between the carrier F6F and F4U totals because they generally operated from the same ships during the same period.
...
Certain tentative conclusions may be reached from these two tables:

(a) The F6F was slightly superior to the F4U in combat, apparently chiefly because of its greater ability to survive damage.*

And on Page 79, Note (e) to Table 29

*The F6F appears to have had considerable advantage over the F4U when flown under the same conditions. Receiving about the same number of hits per sortie in comparable operations, the F6F had a far lower rate of loss per plane hit.* 


As for the roll rates between the F4U-4 and P-47N, you have offered no compelling comparative data (or any comparative data at all for that matter) that supports the F4U-*4* over the P-47*N*. Both are widely reported to have been excellent rollers. It must be possible to generate a valid analysis of the issue with computer modeling. Unless we find test docs, we will have to wait for someone to generate valid manufactured conclusions.


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## renrich (Oct 20, 2009)

Some folks love to talk percentages. 77% of Corsair's air to air kills were fighters. 71% of Hellcat's were fighters. I read that as Corsair was up against more dangerous opponents more often. Impossible to believe that the USN and it's pilots did not know about the Corsair's supposed vulnerability caused by the , TaDa, oil cooler, before the statistical study came out after the war. This vulnerability on this forum appears to me to be in the same category as one of those, "Oh boy, look what I found," deals. As mentioned before the oil cooler in the leading edge of the port wing root , (apparently located in exactly the same location in the Sea Fury) was pretty small, around 12"-18" by 12"-18" and TaDa could be damaged by a rifle bullet. There was a much larger component of the aircraft, and much more important, which could be damaged by a rifle bullet and every fighter in the world had one. That component was the pilot. Which was more likely to be damaged or put totally out of action by the nefarious rifle bullet or a 12.7. 25 mm, or 37 mm round. I submit that the pilot was the one I would worry about. Fact-----Hellcat flew 66530 sorties and had 823 lost to combat. Corsair flew 64051 sorties and had 459 lost to combat. Both seem pretty rugged to me.

Back to the F4U4 V P47N discussion. I suppose I have not proved that the P47N was an inferior roller although from what I have read, the P47s generally were not noted as great rollers(Holy Rollers?) and F4Us were. I am no engineer but I have a hard time understanding how one takes an airplane which did not have great roll rates, extend the wing span and get a better roller. Seems like it would work in the opposite way. There I go with the common sense thing again. The FAA clipped the wings of the Corsair, ( so they would fit in their low overhead hangar decks) and it was said the roll rate increased, (and the stall speed went up.) Intuitively(bad word) that makes sense. Oh well, so much for the roll rate of the two.

By late WW2, fighter were increasingly used in the fighter bomber role. At SL, the F4U4 could do 380 MPH and the P47N could get 365 MPH, both in combat power, according to Dean. The F4U4 was faster than or equal to the P47N all the way to 25000 feet where it began to lose ground. Almost all ACM and every bit of air to ground business took place below 25000 feet. The takeoff distance from an airfield for the F4U1D was 840 feet and for the P47C was 2220 feet, according to Dean. Seems like that would be an advantage for Corsair since forward air fields could be short. That disparity in takeoff difference was probably greater for the F4U4 over the P47N, unless the P47N was not carrying much fuel.
Last point, (every one says "thank goodness") The F4U4, unless I am mistaken was designed for, could and did operate from carriers. The P47N...(are you kidding?) Seems to me that the P47N would be useful as a long range high altitude escort fighter but the F4U4 was more useful in all other roles. End of story!


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## Clay_Allison (Oct 20, 2009)

renrich said:


> Some folks love to talk percentages. 77% of Corsair's air to air kills were fighters. 71% of Hellcat's were fighters. I read that as Corsair was up against more dangerous opponents more often. Impossible to believe that the USN and it's pilots did not know about the Corsair's supposed vulnerability caused by the , TaDa, oil cooler, before the statistical study came out after the war. This vulnerability on this forum appears to me to be in the same category as one of those, "Oh boy, look what I found," deals. As mentioned before the oil cooler in the leading edge of the port wing root , (apparently located in exactly the same location in the Sea Fury) was pretty small, around 12"-18" by 12"-18" and TaDa could be damaged by a rifle bullet. There was a much larger component of the aircraft, and much more important, which could be damaged by a rifle bullet and every fighter in the world had one. That component was the pilot. Which was more likely to be damaged or put totally out of action by the nefarious rifle bullet or a 12.7. 25 mm, or 37 mm round. I submit that the pilot was the one I would worry about. Fact-----Hellcat flew 66530 sorties and had 823 lost to combat. Corsair flew 64051 sorties and had 459 lost to combat. Both seem pretty rugged to me.
> 
> Back to the F4U4 V P47N discussion. I suppose I have not proved that the P47N was an inferior roller although from what I have read, the P47s generally were not noted as great rollers(Holy Rollers?) and F4Us were. I am no engineer but I have a hard time understanding how one takes an airplane which did not have great roll rates, extend the wing span and get a better roller. Seems like it would work in the opposite way. There I go with the common sense thing again. The FAA clipped the wings of the Corsair, ( so they would fit in their low overhead hangar decks) and it was said the roll rate increased, (and the stall speed went up.) Intuitively(bad word) that makes sense. Oh well, so much for the roll rate of the two.
> 
> ...


I'm still not convinced that a highly documented vulnerability on the F4U to ground fire can be cavalierly dismissed as you want it to be. 

The main problem I have with the P-47 is that it was too expensive for ground attack. An un-turbo A-47 would have been an interesting dedicated fighter bomber but that's outside of the scope of the discussion.


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## DAVIDICUS (Oct 20, 2009)

_Impossible to believe that the USN and it's pilots did not know about the Corsair's supposed vulnerability caused by the , TaDa, oil cooler, before the statistical study came out after the war._

Perhaps a review of this thread would be helpful. As I earlier said, "I for one do not find it hard to believe that the fog of ongoing war would obscure the vulnerability of the Corsair. Especially when probably no one was looking at loss rates under comparable circumstances or probably comparative loss rates at all. After all, both aircraft were very sturdy, shared the R-2800 engine and were similarly unbelievably successful against their Japanese opponents."

And as JoeB said, "*F4U and F6F ground fire vulnerability and mountain or mole hill, it is what it is. It's as statistically clear as it ever would be that the F4U was significantly more vulnerable. How important that was would depend a lot on what the key missions were. Early in WWII it wouldn't have been very important at all. By 1945 it was somewhat important. In a war where carrier planes conducted constant air strikes with essentially no air or anti-ship threat for months on end (see: Korea) it was a relatively quite serious issue. It was too late to bring the F6F back, but it almost surely would have been a better a/c for the F4U's mission in Korea. Again see 1945 stats, F4U's did *not* carry more ordnance per sortie from carriers than F6F's, not in actual practice. And in Korea, typically, high value targets weren't being smashed by a few decisive strikes. The realistic goal was harassing the enemy, gradually inflict casualties and damage it was hoped, and only occasionally, perhaps, scoring any really satisfying success. The heavy losses of beat up old F4U-4's were not such a big deal, they were going to the boneyard soon anyway, but the losses of pilots was more of an issue, even from a completely non-sentimental POV of trying to re-expand naval aviation for the Cold War. To this was added the F4U's inherently higher accident rate, especially in the more difficult operating conditions typically faced by carrier a/c in Korea compared to the Pacific War, more especially in the winter time.

But as shown by all these debates here, it wasn't hard at all to miss the fact of greater F4U vulnerability before the stats were accumulated (or in these threads, before people are fully aware of them and just how apples to apples they are). Even afterward naval air thinking emphasized dashing hell-for-leather wars like WWII. And even in the actual conditions of Korea once apparent, leadership simply had a blind spot about air crew losses that didn't make a lot of sense compared to the actual results achieved. It's hard to explain certain decisions in KW any other way (goes for the USAF as well).*"

_[F]rom what I have read, the P47s generally were not noted as great rollers(Holy Rollers?) and F4Us were._

??? You're kidding right? There are references all over the web, in books and by pilots about the excellent roll ability of the P-47 and with the exception of that one piece on the Spitfire Performance site, the consensus is that the P-47 with it's larger wing, larger ailerons and squared wing tips had better roll than the "D". That is not to say that the Corsair wasn't also an excellent roller as well. 

_By late WW2, fighter were increasingly used in the fighter bomber role. At SL, the F4U4 could do 380 MPH and the P47N could get 365 MPH, both in combat power, according to Dean. The F4U4 was faster than or equal to the P47N all the way to 25000 feet where it began to lose ground. Almost all ACM and every bit of air to ground business took place below 25000 feet. The takeoff distance from an airfield for the F4U1D was 840 feet and for the P47C was 2220 feet, according to Dean. Seems like that would be an advantage for Corsair since forward air fields could be short. That disparity in takeoff difference was probably greater for the F4U4 over the P47N, unless the P47N was not carrying much fuel. Last point, (every one says "thank goodness") The F4U4, unless I am mistaken was designed for, could and did operate from carriers. The P47N...(are you kidding?) Seems to me that the P47N would be useful as a long range high altitude escort fighter but the F4U4 was more useful in all other roles. End of story!_

I am a bit confused as to what this has to do with roll rates between the P-47N and F4U-4 or the documented enormous vulnerability of the Corsair to AA fire. Is this a "switch the subject to something that I can defend about the Corsair" tactic? I frankly don't have any desire to check on those performance stats that you have offered or cross check them against other sources. 

At any rate, I will conclude with something else I posted earlier on this thread:

"Lets say we have two contemporary aircraft that appear to perform similarly in the air to ground role. If it came to your attention that one of those aircraft was 58% more likely to be lost from anti-aircraft fire than the other when actually hit by anti-aircraft fire during the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where both aircraft received "about the same number of hits per sortie," would you classify the aircraft that's 58% more likely not to return, leave its pilot dead, behind enemy lines or just somewhere in the water or on the ground as unsuitable in that role?

Put differently, if you could reasonably anticipate losing 16 of one type of aircraft for every 10 of the other type under the apples to apples comparison above, would that move you to declare one of those aircraft as unsuitable? What about if you are a pilot? Do you think you might summarily conclude that one of those aircraft is simply unsuitable in that roll?

There is a certain elasticity to language that often results in disagreements over characterizations. Can we agree that if you were a pilot and were expected to pound defended targets and had a choice between flying a Corsair or Hellcat and knew about the 16:10 loss ratio that you would refuse to go near a Corsair with a 10 foot pole?"

END OF STORY


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## renrich (Oct 20, 2009)

I doubt we will agree on anything having to do with the Hellcat Corsair discussion. I believe the Navy picked the right horse. The thread is supposed to be about P47N and F4U4. For the purposes of late WW2, the F4U4 is the better AC, IMO. I suggest you get a copy of Dean and perhaps your viewpoint will change but at least your viewpoint will be made wider and you will have a lot of fun reading it. It is a truly good book.


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## DAVIDICUS (Oct 20, 2009)

_I suggest you get a copy of Dean and perhaps your viewpoint will change_

Somehow I don't think Dean's book will cause me to reject the enormity of relevant well controlled data which is set out and analyzed in the Naval Air Combat Statistics.

_For the purposes of late WW2, the F4U4 is the better AC, IMO._

I think they were designed with different roles. The P-47N, for instance, was designed to be an extreme range high altitude escort. As was discovered after the war, in the air to ground role, the Corsair was determined to have a fragile glass jaw when compared to the Hellcat. In my opinion, there is no reason to believe that this enormous disparity in vulnerability between the Corsair and Hellcat would not have likewise existed between the F4U-4 and P-47N. In addition, while the Hellcat and Corsair both had 18 gallon oil tanks, the P-47N's oil tank was 40 gallons. Even the P-47D had a 28.7 gallon oil tank which may have contributed to one of its nicknames, "The Unbreakable."


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## DAVIDICUS (Oct 20, 2009)

Pilot Edwin L. King with flak damaged P-47 at Pisa following Silver Star mission of 12 Jan. 1945. Aircraft is 7D3 42-29300. Crew Chief H.D. (Henry) Embry was the photographer of the shot seen many times of the oil-soaked Jug that returned to base after having two jugs shot off during a sortie (pilot Ed King). Embry says that after the shot was taken, his camera was stolen and he had never seen the shot until after the war and many years hence.


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## Messy1 (Oct 20, 2009)

Wow, that looks like that was a exciting ride!


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## DAVIDICUS (Oct 20, 2009)

I bet it's even more exciting if you're only carrying 18 gallons of paint. 

That additional 10+ gallons (P-47D) or additional 22 gallons (P-47N) can come in handy when trying to get back home.


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## Colin1 (Oct 20, 2009)

How often did R28s throw their oil like that?
I heard they were damned reliable and barely seeped oil, let alone threw it.


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## DAVIDICUS (Oct 20, 2009)

Anything mechanical can and will break. The person who sent me these pictures only said that the plane returned after developing an engine problem in flight. I don't think it was from contemporaneous combat damage as the plane is still pregnant with external fuel tank.


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## Colin1 (Oct 20, 2009)

DAVIDICUS said:


> Anything mechanical can and will break...


Well, yeah
So how often did R28s throw their oil like that?


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## Snyperboy (Oct 20, 2009)

P-47s were high-speed fighter interceptors that were lethal "Flying Pillboxes" with 8 M-2 Browning .50 cal machine guns. F4U Corsairs were well, like P-51 Cs I guess. They were meant for speeds of over 380 mph, capable of intercepting and destroying enemy planes. But my money's on the P-47, because it is faster, more heavily armed, and was built for high-altitude interception.


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## vanir (Oct 21, 2009)

I like the F4U for preference but it's not a reasoned opinion. In fact I'm quite surprised and concerned about this oil cooler vulnerability, I'm wondering why the oil cooler couldn't have some armour plate under the leading edge of the wing to protect it. But I just like the Corsair because it's funky. I know it's probably a much bigger hassle, but the -4 variant is very high performance, I'd prefer it. Probably take a P-51H over a P-47N in the USAAF if I could get away with it too. But I do think the P-47N is just brilliant and don't think I'd be in something better, just personal preferences.


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## jugggo (Oct 21, 2009)

Well they both do have their ups and downs, but most definetly the F4U-4 in the 1-on-1. That is if the P47 didnt use its speed to run away. The Corsair was known to out turn the P51(which model not sure) up to 30mph slower. Even though the Jug had a great roll rate, I do not think that it would be able to keep up with the HOG in ACM. IMHO

****side note****
What would do better the FW190-D9 or the F4U-4


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## DAVIDICUS (Oct 21, 2009)

A few other tidbits:

The Pilots Flight Operating Instructions for the F4U-4 (October 1944 T.O. No. AN-01-45HB1) warned that there was only enough oil for a maximum of ten seconds of inverted flight. Also, *where there was damage to an oil cooler with resulting loss of oil, neither the oil pressure gauge nor the oil temperature gauge would register the change in pressure or temperature until all of the oil was out of the system*. (See Manual at page 10) Pilots were warned during combat to check the oil coolers and trailing edges of the wings often for damage that could prove catastrophic.

And another excerpt from Crimson Sky The Air Battle For Korea by John R. Bruning Jr.:

Under the Notes for Chapter 3 on page 215:

#6 Though well armored and generally able to withstand battle damage, the Corsair had an Achilles heel in its oil system. ... After a hit in the oil cooler, the Corsair pilot had only seconds either to bail out or crash-land his plane as the engine overheated and seized. More Corsairs were lost than any other type of Naval aircraft during the first six months of the war as the result, in large measure, of this weakness.

Some anecdotal stuff admittedly of no evidenciary value:

An account from Hal Shook who was a Bolt driver:

_In the summer of 1944, we were flying near the Seine River, trying to stop the German Army from crossing over and regrouping on the other side. Crossing points along the river were under constant aerial attack and were heavily defended with anti aircraft guns. Approaching the river, we ran into heavy flak, ugly black puffs of smoke so thick it looked like you could walk on it. We were dodging and changing altitude trying to outguess the gunners, when we saw five barges on the water, 10,000 feet below. They were heavily loaded with enemy equipment and troops.

As I rolled into my dive bomb run, almost straight down, my P47 Thunderbolt shuddered as heavy shrapnel slammed into the propeller and engine.* Oil streamed out to cover my windscreen ... Bobbing and Jigging from side to side, and with oil still blowing back. I pulled up and away from the river and the flak. Miraculously, the engine was still running. It carried me to an emergency landing strip in Normandy*._


From an interview with Francis Gabreski:

CUNNINGHAM: Your combat experience, Colonel... was there any one action that stands out in your mind, any combat that you particularly remember?

GABRESKI: So he came down, and I broke into him. And as he went on by me, firing, I pulled up in sort of a chandelle. As my airspeed was dropping, he came back up again, turned around, and started coming into me. As he was coming up, I gave him a 90-degree deflection shot. Well, the first deflection shot was great. In other words, he fired and I could see the 20 millimeter gun spittin' smoke, or spittin' fire. I broke and he lost his airspeed, and I went down into him and he came down after me and we picked up enough speed and went . . . I did that twice, and on the third one I had all the confidence now that I was gonna run him out of ammunition.

So the third time we went ahead and did this same thing and he came up with about a 90-degree deflection shot again, the same shot that I'd been giving him. I was very fortunate the first two times, but that last time he rang the bell. I mean, he really hit me!I heard an explosion in the cockpit and I felt my foot grow numb. I lost power in my engine. I says, "Oh, boy!" So the first thought that came to my mind was that the high explosive blew up as it hit my foot. And the second thought that came to my mind was, "oh, he hit my engine, so that's it. I'm out of power and I've gotta go down - bail out - whatever." So I pointed the nose down again, rolled over in kinda a steep dive, pointed the nose down and I was afraid to look at the foot because with the sight of blood, or something like that, I mighta gone into shock and passed out. So I didn't look. I pulled back on the canopy and was ready to bail out. I looked at my airspeed indicator and I still had plenty of airspeed, but my RPM started coming down and my manifold pressure started coming up. So the thought again occurred to me that, "Well, it must be the turbine supercharger and not the engine." And then I looked at the foot and at the pedal. The pedal was shot away but the foot was in good shape. I had heavy boots on and the bottom side of the boot was kinda shredded and broken up. But the foot was in good shape. ... And I soon discovered, after the individuals at that airbase came out and met me on the runway with the engine shut down and so forth . . . *they discovered that the oil tank was practically dry*.


Account from P-47 Pilot Gildas David McDowell:

On October 14, 1944 we were sent deep into German-held areas of France to locate and destroy any transportation, mainly trains. On my 42nd mission we found a very long freight train sitting out in the open. As standard operating procedure two of us dropped down to check it out for protection. When we strafed at high speed, I saw no sign of protection. In such cases we would then take turns going down to shoot it up at slow speeds.

But as I lined up to start my strafing run I was surprised to see the boxcar doors opening up and the roofs of some boxcars also open. In no time it was clear we had flown into an anti-aircraft trap.* I saw many balls of fire coming at me. The first hit was directly into my engine, then one in the right wing. I continued strafing until I passed over them. Then we headed back to friendly territory. Oil and smoke were blowing back over my aircraft. The oil pressure dropped to zero and the cylinder head temp went up to the peg. I climbed to 7,000 feet but could not catch up with the rest. Any time I advanced my power, the engine would vibrate violently. I figured that my prop had been severely damaged.

I landed at the edge of some woods* and could see soldiers were running up the hill towards me. I ran into the woods and hid under a brush pile. A few hours later I heard barking dogs approaching so I ran out the far side of the woods. But by this time they had the area surrounded; so I became a prisoner of war.


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## FLYBOYJ (Oct 21, 2009)

DAVIDICUS said:


> Lastly the Pilots Flight Operating Instructions for the F4U-4 (October 1944 T.O. No. AN-01-45HB1) warned that there was only enough oil for a maximum of* ten seconds of inverted flight*. Also, where there was damage to an oil cooler with resulting loss of oil, neither the oil pressure gauge nor the oil temperature gauge would register the change in pressure or temperature until all of the oil was out of the system. (See Manual at page 10) Pilots were warned during combat to check the oil coolers and trailing edges of the wings often for damage that could prove catastrophic.



Actually that's SOP for a number of round recip aircraft - I didn't go through the whole thread today to see if anythng was posted on the P-47 with the same limitation.


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## DAVIDICUS (Oct 21, 2009)

I didn't know that. I have P-47 manuals for B, C, D, M and N and I do know that there are no warnings about loss of oil pressure and high temperatures from combat damage not being displayed to the pilot.


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## DAVIDICUS (Nov 15, 2009)

More on the general discussion regarding whether the P-47 was a good roller. 


August 23, 1943 Memorandum Report on USAAF evaluation of flight characteristics of F4U-1 for the purpose of determining combat and maneuverability characteristics.

3. Combat Characteristics
...
B. F4U-1 vs. P-47C
...
6. The airplanes have the same rate of roll in level flight speed but at 300mph the P-47C is better and remains better as diving speeds increase.

http://www.wwiiaircraftperformance.org/f4u/f4u-1-02296.pdf


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## renrich (Nov 16, 2009)

That information on the roll rate of P47C does not match up with the the steady roll rate graph based on NACA information. The P47C according to it has a peak roll rate of 84 degrees per second, limited by a 50 pound stick force, at about 225 mph IAS, where it begins to drop off steadily.


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## billswagger (Jan 7, 2010)

That data is a bit old pluss we are looking at the P-47N which was definately faster in rate of roll over the D model.

The comparison is close as I've seen climb data that actual puts the F4U and P-47 at near equivalent climb rates up to 30k where the P-47 gains a significant climb advantage of 1000fpm. 
The best climb of the P-47N at gross normal weight is 3580ft minute, and the F4U-4 appears to be about the same. 

P-47N is faster by about 30mph in level flight.

The F4U trades dive speed for turn, although in a clean configuration (ei no flaps) the P-47D had a better turn rate than the FG-1 airframe. Given the similarity of the later model airframes i don't think that there would be much difference there. 

As for turn radius there is no doubt the F4U could make a tighter turn. The P-47N was a heavier plane, and i dont see turn radius getting any better for the P-47 in that regard. 

Fire power and payloads, Both very capable and i would say could perform equivelant tasks except for obvious reasons the N had better range. 

I think the P-47N is the better fighter only because it could fly higher and faster in combat enviornment where most JPN fighters could out turn and out climb American fighters by a significant margin. 

I saw another thread about Ki-84 being better in climb rate than the N model, but i would argue not in the zoom climb which both the F4U and P-47 airframes excelled at. 



Bill


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## renrich (Jan 7, 2010)

The P47N is faster in level flight at what altitude? How do they compare at SL, 10K, 20K feet?


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## davparlr (Jan 8, 2010)

renrich said:


> The P47N is faster in level flight at what altitude? How do they compare at SL, 10K, 20K feet?



About the best I can get is as follows:

SL
F4U-4 *379*
P-47N * 364*

10k
F4U-4 *395*
P-47N *399*

20K
F4U-4 *433*
P-47N *434*

But there is other data


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## billswagger (Jan 8, 2010)

P-47N
http://www.wwiiaircraftperformance.org/p-47/p-47n-republic-wep.jpg


F4U-4
http://www.wwiiaircraftperformance.org/f4u/80765-level.jpg

I was looking at these two graphs, but i saw more information on this site that also showed this:

http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf

It plots the initial climb rate closer to 4800 ft per minute.

With 150 gal tank and pylons for rockets 
S L = 374mph
10,000ft = 420mph
20,000ft = 440mph peak at 22kft 451mph
30,000ft = 420mph

clean config, no pylons, no tanks:
SL: = 383mph
20,500 = 463mph


In light of this, the F4U may have matched the P47N in top speed in clean configuration, however now i have to wonder if the performance of the N would've been similar to the M if it was tested with out pylons. 

Needless to say, the F4U may have been the better plane for lower altitude engagements and point interception with a starting RoC of 4800ft/min. 



Bill


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## renrich (Jan 8, 2010)

No question that the two aircraft were optimised for different missions. This is somewhat off topic but I always have wondered why the F4U5 did not go with the bubble canopy. The FG?, (don't want to look it up but the AC with the R3350?) had the bubble canopy and looks as if visibility would have been improved.


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## drgondog (Jan 8, 2010)

billswagger said:


> P-47N
> http://www.wwiiaircraftperformance.org/p-47/p-47n-republic-wep.jpg
> 
> 
> ...


Pylons should reduce speed by ~ 10mph but neither the P-47N or the P-51D-H would have a mission in which pylons were removed..

These discussions often dive into flight test data without context and the reporst have to be fully examined to understand loadout for fuel and ammo - as well as fuel type/boost parameters.

One thing that also should be speculated about - what are the likely conditions these ships would have at most likely point of engagement.

For Mustang and P-47N it is at or around target area during penetration through withdrawal... 

For F4U and F6F it might be closer to 300 mile radius from carrier.

For Me 109 and Fw 190 and Spit, even closer to point of origin.

Because of nature of drop tanks and mission, both the P-51 and P-47 are likely to have most of their internal fuel remaining when they punch drop tanks for a fight.. The other birds are more likely to have ~ 2/3 internal fuel at radius of contact.

Daveparl has hit this point repeatedly in various comparisons


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## MikeGazdik (Jan 9, 2010)

renrich said:


> No question that the two aircraft were optimised for different missions. This is somewhat off topic but I always have wondered why the F4U5 did not go with the bubble canopy. The FG?, (don't want to look it up but the AC with the R3350?) had the bubble canopy and looks as if visibility would have been improved.



FG2 Corsair. Powered by the P&W R4360 though, not the Wright R3350. And I never thought of that, I wonder why they did not use the FG2 airframe after the F4U-4. Seems only logical.


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## FighterFool (Jan 10, 2010)

I don't know if anyone is still following this thread, but if so, I heartily recommend each of you read Robert S. Johnson's excellent biography, "Thunderbolt". As I recall, Bob Johnson was the leading Thunderbolt ace. In his story he reports of "Jugs" returning to base with big pieces of tree branches lodged in their wing leading edges and even bricks in their engine cowlings from inadventant encounters with chimneys during low altitude sweeps over Europe. He also relates his own experience of being shot up over Europe, and, being unable to get the canopy open far enough to bail out, nursing his plane back to England to land at his base. After being freed from his plane he counted over 100 bullet holes and 6-20mm shell holes while standing in one place. Cylinder(s?) had been shot away from the engine, etc. The place was junk, but it brought him home. It's been years since I last read the book, now I think I'll have to find it again!!


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## renrich (Jan 10, 2010)

I have the book and have quoted from it several times as have other members of the forum. The episode where he went home with a jammed canopy and was shot up by an FW with no cannon ammo left has been discussed often.


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## zpd307 (Jan 10, 2010)

i have talked with two ww ii veteran pilots that live here in town. actually three, but one was a p-47 pilot, one was a f4u- pilot and one was a b-24 pilot. they were all partial to their own aircraft..... didnt see that one coming, did you?


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## DAVIDICUS (Jan 10, 2010)

I was at the Evergreen Aviation Museum (home to the Spruce Goose) earlier this week. They have some WWII combat aircraft sitting together on the east side of the museum including a Hellcat, Corsair, Spitfire, Bf-109, B-17, P-51, P-38, A-26 and Avenger. Because I was there during the week it wasn't very busy. The docents outnumbered the patrons. One of the docents approached me as I stood between the Hellcat and Corsair and began telling me the kill statistics for the Hellcat and I raised the subject of the Naval Air Combat Statistics' tentative conclusion that the F6F was slightly superior to the F4U in combat, apparently chiefly because of its greater ability to survive damage. 

A few minutes into listening to my summary of the data, he asked if I could stay there for a minute while he retrieved one of the other docents who flew Corsairs in Korea. A couple of minutes later, he returned with another docent, Rob, who flew Corsairs off of a carrier in combat. The other docent introduced Rob into the conversation by reiterated some of what I had said about the striking vulnerability of the Corsair and Rob just looked at me and nodded his head.

He wasn't familiar with the striking disparity between the Hellcat and Corsair revealed by the Navy's combat statistics but said he wasn't surprised. He said that the vulnerability of the Corsair's oil cooler was well known and was a source of anger on the part of pilots who thought a redesign would make them safer. He said it was always on their mind and that sometimes "you wouldn't get too low" in your attack due to that specific concern. He also said that Skyraider pilots did not have the same concern.

It's a great museum, although extremely expensive! There is a separate space museum there too and the cost for myself and six year old son to go through the aviation museum, space museum and to see an IMAX film was ... brace yourself ... $60.00.


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## renrich (Jan 10, 2010)

I still wonder about how big the infamous oil cooler in the Corsair was and what was the probability of it being hit and if that was such a universally known weak point why the oil cooler in the Hawker Sea Fury was located similarly. The fact still remains that the Corsair delivered many more tons of bombs then did the Hellcat in WW2 and had less losses to triple A. The fact is that the Corsair did yeoman duty in Korea and was quite effective.


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## DAVIDICUS (Jan 10, 2010)

I don't think it's surprising that lessons learned only well into 1946 would not have guided aircraft design years earlier. The Naval Air Combat Statistics wasn't published until mid 1946 and it did not mention the oil cooler as culprit. And I frankly don't know that the Sea Fury did not have some remedial armor plate or deflection apparatus installed to address this as the later AU-1 Corsair did.

The probability of the oil cooling system being hit was certainly greater than with the Hellcat as it is spread over a larger area. There was also the related issue of the pilot's oil pressure gauge not registering a loss of pressure until almost all the oil had left the system. The Corsair operating manual states that the pilot should check the trailing edges of the wings frequently in combat for that reason. The manual for the Hellcat has no such caveat. Similarly, the manual for the Thunderbolt, which shares the same oil cooling design as the Hellcat, makes no mention of this either.

The fact that the Corsair dropped more bombs than the Hellcat in WWII has no relevance to the Corsair's relative vulnerability realized in 1946.

The fact that fewer Corsair's were lost in AA fire than Hellcat's under circumstances that are not apples to apples makes any conclusions about the two aircraft relative to vulnerability to AA damage merely speculative. 

Now, if you had, say, data for 22,000 sorties for the Hellcat and Corsair for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" from AA fire, I think you would have an overwhelming mountain of evidence from which to base concrete conclusions regarding comparative vulnerability to AA fire. 

And I'm sure that if such a mountain of apples to apples data showed that the Hellcat was 58% more likely not to return after suffering AA fire than the Corsair, that you would agree that the Corsair is an even awesomer plane than was previously thought.


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## renrich (Jan 11, 2010)

I don't know about it being awesomer although that sounds like an awesome word but it seems unreasonable to me that if the oil cooler was as big a problem for the Corsair as portrayed by statiticians, pilots would have been screaming to high heaven from early 1943 on as in, when a pilot was picked up out of the drink he would say, " It was that dratted, dad gum oil cooler again and why does not Vought do something about it?" An example is that a pilot was lost because he accidently while in combat used the CO2 blow down bottle for the landing gear instead of the CO2 bottle for purging the wing fuel tanks. They were located side by side and after a chew out for Boone Guyton, chief test pilot for the Corsair, by an admiral, Vought changed the location for the bottles.That was not as big a modification as relocating or armoring the oil cooler but if that was an extreme vulnerability it would have been fixed IMO. Also to say that the extreme difference between Hellcat losses to AAA and Corsair losses to AAA is not a valid point because they did not happen side by side seems unreasonable to me. No reflection on anyone here on this forum but the old adage, " there are lies, damn lies and statistics," comes to mind here. If old guys at an air museum were very conscious of the oil cooler problem on Corsairs in Korea, one wonders why WW2 pilots did not raise the issue continually. Incidently, Boone Guyton never mentions any oil cooler issues in his book, "Whistling Death."


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## DAVIDICUS (Jan 11, 2010)

Renrich, see posts *#318*, *#319* and of course, *#320*. 

_No reflection on anyone here on this forum but the old adage, " there are lies, damn lies and statistics," comes to mind here._

The thing about that old adage is that the data always reveals the lies, damn lies and statistics. Like when we are told that women only earn .74 cents for every dollar that a man earns which is then twisted into some sort of apples to apples comparison between men and women, job for job, by those with a radical feminist agenda. Turns out that they just take all the money earned by women and divide by the number of women and then all the money earned by men and divide by the number of men. Looking at the data in the study reveals this. Turns out that when you control for variables that govern pay in a specific position, women's pay is closer to .97 for every $1.00 that a man earns. 

This is why controlling for variables is so important. Here we have data for 22,000 sorties for the Hellcat and Corsair for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" from AA fire. A more well controlled study you won't find and could not ask for. As I said in post #366, "We have more controlled data to support the enormous disparity in vulnerability between the Corsair and Hellcat than to support any disparity existing at all between the Mustang and Thunderbolt."

When you say that for the whole of WWII there were fewer Corsairs lost to AA fire than Hellcats and try to pass that off as evidence on the issue of vulnerability of the Corsair relative to the Hellcat, lies, damn lies and statistics does indeed come to mind. In your own post #365, you said, "_I don't believe that the statistical study is valid because there are too many variables_." So now we are adopting stats for the whole war with no controlling for variables at all as long as we can get to a number we want?

_Incidently, Boone Guyton never mentions any oil cooler issues in his book, "Whistling Death." _

And for a littany of sources that do reference the oil cooler issue, see post *#333* and *#362*. Obviously an oil cooler hit can bring down any plane and incidentally, I have never come across any source that singles out the oil cooler as a special Achilles heel for the Hellcat or Thunderbolt which share a different design/ layout.


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## renrich (Jan 11, 2010)

Maybe a typo in your post but in WW2, the Corsair dropped more than twice the tonnage of munitions than the Hellcat and had only 349 losses to AAA compared to 553 losses to AAA for the Hellcat. I am not saying that the Hellcat was more vulnerable to AAA and not saying that the Corsair was not more vulnerable but one could take the fact that the Hellcat suffered 553 losses while dropping 6503 tons of bombs and the Corsair dropped 15621 tons of bombs while suffering 349 AAA losses and come up with a nice argument that the Hellcat was a lot more dangerous to bomb in than the Corsair. To me that argument doesn't hold water because of the variables. If the oil cooler armoring or relocating had not been desirable, they would not have done it on the AU and F4U7. I just don't believe it was the deficiency you and some others make it out to be. The Corsair was used as a dive bomber more than the Hellcat because it was better in that role, almost as accurate as a Dauntless. Maybe that accounts for the apparent excessive vulnerability in comparable missions. I don't know about you but a bird coming straight at me is easier to hit than a passing shot. As far as data in comparable missions is concerned, I am amused at how accurate you think it is. How do they know how many hits a downed aircraft took and where the hits occured. Did they go dig up the wreckage on every downed Hellcat or Corsair. I call BS on that. I know a pilot who flew missions in Korea in the AD and Corsair. He never mentioned worrying about his oil cooler but that proves nothing. If you read Guyton's book he describes many problems with the Corsair but never mentions the oil cooler. That proves nothing either. The only thing we know for a fact is that the Corsair flew lots more air to ground missions and had less losses to AA. We also know that in comparable missions which the Navy kept records on the Hellcat had less losses and that the number of hits and their location seems to indicate the oil cooler was a vulnerability for the Corsair. As to how big that vulnerability was I say we can't be sure because I am absolutely certain that the Navy does not know how many hits each airplane took and where they were located.


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## DAVIDICUS (Jan 11, 2010)

_I am not saying that the Hellcat was more vulnerable to AAA and not saying that the Corsair was not more vulnerable but one could take the fact that the Hellcat suffered 553 losses while dropping 6503 tons of bombs and the Corsair dropped 15621 tons of bombs while suffering 349 AAA losses and come up with a nice argument that the Hellcat was a lot more dangerous to bomb in than the Corsair._

Yes, lies, damn lies and statistics do make nice arguments. To quote you, "I don't believe that the statistical study is valid because there are too many variables." You talk the talk but don't seem to want to walk the walk.

_As far as data in comparable missions is concerned, I am amused at how accurate you think it is. How do they know how many hits a downed aircraft took and where the hits occurred. Did they go dig up the wreckage on every downed Hellcat or Corsair. I call BS on that._

The huge number of events (sorties) and the Navy's own declaration of same time period, flying from the same ships on missions under the "same conditions" in "comparable operations" speaks both definitively and authoritatively. Did I ever say that the Naval Air Combat Statistics made any representations whatsoever as to how many hits or placement of hits? Again, from my post #403: 

"The Naval Air Combat Statistics wasn't published until mid 1946 and *it did not mention the oil cooler as culprit*." 

It also does not mention number of hits on planes suffering damage or locations of hits on planes suffering damage. The study controlled just for planes actually suffering AA damage. The enormous number of sorties and well controlled same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" is what makes the study and its conclusions valid. 

"_I don't know about you but a bird coming straight at me is easier to hit than a passing shot._"

Good point. So if these dive bombing missions only undertaken by the Corsair were causing more AA losses as a result of it being easier to hit the Corsairs, wouldn't that make for significantly more hits on Corsairs? How do we reconcile that with the fact that the Corsairs and Hellcats took "about the same number of hits per sortie" which one would expect and serves as further validation when we are looking at the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations".

Do you really think that using Corsairs for some dive bombing is what is causing the more than 22,000 sorties for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" to reflect a 58% greater chance of not returning after actually suffering AA damage? Would we really be having this discussion if the data had went to other way - against the Hellcat?

_As to how big that vulnerability was I say we can't be sure because I am absolutely certain that the Navy does not know how many hits each airplane took and where they were located_.

You are right. All the Navy knows is that in looking at more than 22,000 sorties for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie", the Corsair was 58% less likely to return. ... Oh, and they addressed an oil cooler vulnerability issue on the AU-1.

"_I just don't believe it was the deficiency you and some others make it out to be._"

You almost make it seem as though "some others" and myself are in the minority. This issue has been vetted for quite a while now across this and other threads and you, my friend, are the only person who has stepped forward with disbelief to challenge the NACS. I would add that it is plain to everyone (and everyone has followed this issue) that your disbelief is not grounded in any inability to grasp the data. As I have pointed out several times, had the data gone the other way, you would be the NACS's chief proponent on the issue of Hellcat vs. Corsair relative vulnerability to AA.


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## renrich (Jan 11, 2010)

If you bothered to read my earlier posts, I mentioned that the oil cooler problem caused a fix to be undertaken in the AU and the F4U7.
Another point is that 22000 sorties sounds like a lot of sorties. Were the number of sorties divided equally between the two types? I would guess that the number of sorties flown by Hellcats was greater than those flown by Corsairs. Did they identify which sorties were flown by which types in a dive bombing mode or a glide bombing mode? Since only 349 Corsairs were lost to AAA in the whole war out of around 11500 built it does not sound as if the percentage of Corsairs lost in the 11000 or so sorties is very high.


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## DAVIDICUS (Jan 11, 2010)

_If you bothered to read my earlier posts, I mentioned that the oil cooler problem caused a fix to be undertaken in the AU and the F4U7._

Yes, well I also read your earlier comment (Post #365) that "I don't believe that the statistical study is valid because there are too many variables" after which you then decided to adopt stats for the entire war without any attempt to control for anything. This sort of boggles the mind. You want to ditch the Naval Air Combat Statistics controlled data for the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" because there are too many uncontrolled variables and instead adopt the entire war without any attempt to control any variables whatsoever? 

Do I really need to respond to that?

Why would the number of sorties need to be divided equally between the two aircraft? ??? The data set for the Corsair was *6,000*! Again, if the differential in population size was skewing results, then we wouldn't see "about the same number of hits per sortie" under circumstances where we have the same time period, operating off the same ships, where missions were under the "same conditions" in "comparable operations." That's really the inescapable glue that holds this analysis together (*the two aircraft received "about the same number of hits per sortie"*) and in the end, when the well controlled data is out on the table, no amount of lies, damn lies and statistical manipulation can alter the facts and necessary conclusions that flow from those facts.

When you hear of a study that shows that even when lifestyle and diet are controlled for, blacks have a lower life expectancy than whites, do you similarly reject such a finding because the population of blacks is less than 1/5 of the white population? Does the difference in population size pose an insurmountable obstacle to the drawing of valid conclusions?

I do not see a break down of dive bombing mode or glide bombing mode and still don't see the relevance. You yourself just argued that the Corsairs would have been easier targets to hit utilizing dive bombing tactics which only they would have employed right? ("_Maybe that accounts for the apparent excessive vulnerability in comparable missions. I don't know about you but a bird coming straight at me is easier to hit than a passing shot_.") You were apparently trying to account for the reason why fewer Corsairs returned to their ships. You forgot, however, that the two aircraft received "about the same number of hits per sortie" which really just confirms that the missions and conditions under which they were flying were the same thus undercutting your argument. What am I missing?


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## DAVIDICUS (Jan 13, 2010)

On the subject of taking AA fire and making it back -- WOW.

(Photo from a post by BC1 on another thread.)


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## Duke Soddy (Jan 16, 2010)

DAVIDICUS said:


> I'm curious which of these were better in the air to air role and why.



This is such a tough one, I like both of the aircraft. Objectively they both have reputations as rugged and durable aircraft, but the jug edges out the corsair in that arena. The Corsair would edge the Jug out in wing loading and everywhere else except in range. Give any combination of variables in a combat scenario for the two to perform in, you could honestly say in WWII either one of these planes would have and did perform the air to air combat role well.

P-47, for its survivability. If I were a pilot to choose, I want the one with the reputation to bring me home.


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## Duke Soddy (Jan 16, 2010)

What your missing is ... Figures don't lie, but liars do figure.


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## Soren (Jan 16, 2010)

The F4U was overall the superior fighter, there's no doubt about that, it was more maneuverable and faster than the P-47. It was only at high altitudes that the P-47 was better. Both were great a/c though.


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## Clay_Allison (Jan 18, 2010)

Dogfighting on the deck: F4U
Flying top cover/bomber escort: P-47
Strafing Ground Targets: P-47
Attacking enemy airfields: F4U
Fighting Japanese: F4U
Fighting Germans: P-47
Dropping Bombs/Attacking Ships: F4U


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## keystonekid60 (Sep 27, 2010)

Amen to that,what an aircraft was designed to do and what it actually ended up doing in combat are two totally different things. Also about the jug versus bent-wing,the F-4 eventually got 4 "count em 4 20 mm canons,now that's firepower in my book!


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## davparlr (Oct 2, 2010)

These two powerful aircraft are closing out the era of propeller driven fighters. Both are advanced designs of successful aircraft and both are powered by the R-2800 eng. Both have a justified reputation of being rugged aircraft. The main difference is that the F4U-4 is an engine driven supercharged aircraft designed for carrier use, the P-47N is a turbo-charged engine designed for high altitude escort and long range interdiction.

Comparing the performance of these two aircraft with equal fuel and weapons load results in the following stats.

At SL, the P-47N with 2600 hp available, out powers the F4U-4 at 2450 hp, but gives up around 1600 lbs in weight. As a result, the F4U has better power to weight and wing loading than the P-47, even with larger wings, and is slightly faster. Both climb well being in the 4000 ft/min range, but the F4U still has an advantage.

At 10k, things begin to change. The P-47’s engine now develops 2800 hp, a value it will hold to about 33k ft. The F4U engine is generating about 2000 hp at this altitude. The P-47 is pulling about 5 lb/hp and the F4U has about 6.2 lbs/hp. The P-47 will have better acceleration and reducing climb disadvantage. Climb should still be in the F4Us favor and has a good amount of airspeed advantage.

At 20k, the situation is roughly the same. F4U hp has dropped 100 hp, so the P-47N has 900 hp more than the F4U. The F4U still has an airspeed advantage over the P-47.

Above 20k, the P-47, with over 50% more power available, starts to get into it strength, increasing in speed. Above 25k, very few, if any, aircraft is going to stay with it, at least up through 35k.

My conclusion, the F4U-4 will have an advantage below 20k, but suffers a bit in power loading. From 20k to 25k, pretty equal, above 25k the P-47N is the plane to have.


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## renrich (Oct 2, 2010)

Dav, very good summation, IMO. Also, IMO, the F4U4 has overall. three big advantages over the P47. They are:
The F4U4 can equally operate from a carrier deck and a very short land base. The P47N cannot.
The F4U4 has a maneuverability advantage over the P47N, especially below 25000 feet. 
The F4U4's advantages are below 25000 feet where almost all ACM in WW2 takes place.


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## Colin1 (Oct 2, 2010)

Good summary Dav

each plane was tailored well for the service/arm for which it was designed


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## windswords (Oct 3, 2010)

"The F4U4 can equally operate from a carrier deck and a very short land base. The P47N cannot.
The F4U4 has a maneuverability advantage over the P47N, especially below 25000 feet.
The F4U4's advantages are below 25000 feet where almost all ACM in WW2 takes place."

The Bolt would have carrier capability too if they outfitted it with arrestor gear and strengthened landing gear- and if they could find a carrier with a big enough landing deck! So I don't think it matters here. Besides, the Bolt has a thousand mile greater range.

Now about maneuverability below 25K feet. In Europe the Bolt faced planes that were more maneuverable - the Me-109 and FW-190 - and blew them out of the sky. Most of that combat took place below 25000 ft, especially later in the war when the Bolts were relegated to low level ground attack. If they faced enemy fighter opposition down on the deck they had to fend for themselves. There were no Mustangs flying top cover for them. In the Pacific practically every Japanese fighter they faced were more maneuverable than the Bolts. I don't remember combat pilots complaining that their mounts were not maneuverable enough against the Japanese.

Most of us agree that the maneuver vs.energy fighter debate was was won by the energy fighter. Why are we all of a sudden giving so much credence to the Corsairs greater maneuverability? Of more importance should be speed, armor, armament, and overall toughness. Not to mention the greater roll rate and dive speed of the Bolt. So yes the Corsair has some advantages but the advantages of the Bolt are more important when it comes to air to air combat - as it was practiced in WWII, not as it's played in modern combat simulation games.


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## drgondog (Oct 4, 2010)

windswords said:


> The Bolt would have carrier capability too if they outfitted it with arrestor gear and strengthened landing gear- and if they could find a carrier with a big enough landing deck! So I don't think it matters here. Besides, the Bolt has a thousand mile greater range.
> 
> *There has never been a vessel long enough to launch a P-47 of any variety with a full load of fuel to take advantage of the range differential - so that would be a spurious argument.*
> 
> ...



As earlier posters commented the discussion is about F4U-4 and -5s against the best of the P-47s - the N.

I believe Dave summed up the performance distinctions quite well. The air to air combat ratio in the Pacific is heavily weighted against the earlier P-47D Jug in comparison, but the Corsair didn't fight as consistently tough/skilled Japanese pilots until the end of the war. I haven't seen the data but it would be interesting to compare for the Okinawa and Korea fights between the two ships but that data is nowhere as comprehensive as ETO.


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## tail end charlie (Oct 4, 2010)

Wouldnt the carrier need a reinforced deck for a jug to land?


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## FLYBOYJ (Oct 4, 2010)

tail end charlie said:


> Wouldnt the carrier need a reinforced deck for a jug to land?


No. A TBM weighs just as much


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## renrich (Oct 4, 2010)

From Linnekin, "Eighty Knots to Mach 2" "The airplane had a huge turbosupercharger that by a combination of drag and mechanical power bleed off must have caused a substantial performance degradation at other than optimum altitudes. I know a couple of people who had an inadvertent encounter with four late model P47s one day in 1947. (Inadvertent, hell. The Bearcats jumped them. What did you expect? The P47s were there.) It was no contest----partly because the Bearcat, below ten thousand feet, could do absolutely everything better than anything with a propellor and at low altitudes could out accellerate most contemporary jets. Nonetheless, our guys said that AD Skyraiders and even SB2C Helldrivers flown aggressively had at other times given them as much trouble as the P47s."

Notice his use of " at other than optimum altitudes." That tells the story, IMO.

Takeoff distance comparisons- from "America's Hundred Thousand"
P47D-25 2540 feet
F4U4 710 feet


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## Shortround6 (Oct 4, 2010)

It is not only weight but landing speed and sink rate. 

For illustration sake I will make up a few numbers, feel free to plug in real numbers.

If, for instance, the P-47 hits the wires at 85knots and the TBM hits them at 75knots the P-47 needs the arresting gear to absorb/dissipate about 28% more energy assuming both weigh exactly the same. Energy goes up with the square of the speed. Subtracting 30 knots for the speed of the carrier gives you 55knots to 45 knots which means the P-47 is hitting the wires almost 50% harder than the TBM. 
I don't know the sink rate for either plane, maybe the P-47 does come in faster but flatter, but if it doesn't?
A sink rate even 10% higher than the TBM means a 21% higher impact load on the deck. 

While army planes were ferried on carriers there are good reasons why they weren't often operated AS carrier planes. There is more to it than adding a hook. 
Hurricanes and Spitfires had relatively low wing loadings and stalling speeds and they had trouble.


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## tomo pauk (Oct 4, 2010)

renrich said:


> From Linnekin, "Eighty Knots to Mach 2" "The airplane had a huge turbosupercharger that by a combination of drag and mechanical power bleed off must have caused a substantial performance degradation at other than optimum altitudes.
> ...



Think mr. Linnekin is wrong here, turbos do not rob power from engine as mechanical superchargers do. And "must have caused" phrase is vague in any sense.


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## renrich (Oct 4, 2010)

TP, Linnekin is(or was) a retired Navy pilot who flew everything from a Stearman to an F4. He is an aeronautical engineer and a Navy test pilot. I wondered about that statement also but later ran across, somewhere, some information that proves his point. I would not want to go against him in technical knowledge. Page 106, "America's Hundred Thousand" The P47 had a two stage system with two blowers or compressors. The first stage was driven mechchanically by the engine. The second stage was driven by exhaust gasses. So there is mechanical bleed off.

Page 282 AHT, P47 N performance is depicted in the curves of Graph 33. Speed performance of the N model was down five to ten mph from the P47M because the P47N was bigger and heavier with the same engine but the real difference was in climb performance which at combat power was less than that of early Thunderbolts and at military power hardly exceeded 1700 FPM up to 20000 feet. 

Have mentioned this before but one of my uncles was a Pilot Instructor in P39s and P47s. He told me that when they were bounced by Corsairs, they had no chance. That was undoubtedly at lower altitudes.


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## tail end charlie (Oct 4, 2010)

I frequently get lost with abbreviations but figure it out eventually, what is a TBM please?


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## Messy1 (Oct 4, 2010)

tail end charlie said:


> I frequently get lost with abbreviations but figure it out eventually, what is a TBM please?



Flyboy was referring to the TBM Grumman Avenger torpedo bomber.


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## Colin1 (Oct 4, 2010)

tail end charlie said:


> I frequently get lost with abbreviations but figure it out eventually, what is a TBM please?


Grumman Avenger
there were two designations

TBFs were built by Grumman themselves
TBMs were built by the Eastland Aircraft Division of GM


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## vikingBerserker (Oct 4, 2010)

A P-47 needs almost a half mile of runway to take off? WOW!


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## Messy1 (Oct 4, 2010)

vikingBerserker said:


> A P-47 needs almost a half mile of runway to take off? WOW!



I noticed that too VB! That's crazy!! 
I bet a Sherman would use less runway!


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## Shortround6 (Oct 4, 2010)

renrich said:


> Page 106, "America's Hundred Thousand" The P47 had a two stage system with two blowers or compressors. The first stage was driven mechchanically by the engine. The second stage was driven by exhaust gasses. So there is mechanical bleed off.



Fine but the Corsair also used a two stage system. Both stages being mechanically driven by the engine. At low altitudes (under 10,000ft or so?) the 1st stage was disconnected and the engine was supplied by pretty much the same single stage supercharger as the P-47. With the waste gates on the turbo pretty much wide open at these low altitudes the the increase in back pressure would be fairly minor although there wouldn't be much in the way of exhaust thrust. Both planes used air to air inter-coolers between the 1st and second stages so the Corsair is hauling around that weight and bulk. Corsair does use a system where intake air can be routed from the air intakes to the inlet of the second stage without going through the rest of the plumbing/ ducting which may help. Some people claim that this is the difference between the F4F and the F6F.


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## renrich (Oct 4, 2010)

SR, this says the same as you but sounds different, I think. " The main blower was always speed up geared to the engine crankshaft and thus ran when ever the engine turned over. The auxiliary (second stage) blower and it's two sets of different speed up gearing could be clutched to and declutched from the crankshaft via a control in the cockpit." This was the system on the R1830 and R2800.


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## davparlr (Oct 4, 2010)

renrich said:


> Dav, very good summation, IMO. Also, IMO, the F4U4 has overall. three big advantages over the P47. They are:
> The F4U4 can equally operate from a carrier deck and a very short land base. The P47N cannot.


This is some advantage for the F4U. The P-47N offsets this somewhat with great range. There were not very many places the P-47N could not reach in the Pacific when the P-47N and the F4U-4 became available.



> The F4U4 has a maneuverability advantage over the P47N, especially below 25000 feet.



Below 10k ft, I would agree, but from 10k up, the extra 800 to 1000 hp of the P-47M certainly would mitigate the 8% increase in wing loading. I think the maneuvering advantage is still with the F4U but it would not be a big advantage.



windswords said:


> The Bolt would have carrier capability too if they outfitted it with arrestor gear and strengthened landing gear- and if they could find a carrier with a big enough landing deck!



I don’t think landing is the issue. The four times take off distance of the P-47 vs. F4U is the issue!



renrich said:


> I know a couple of people who had an inadvertent encounter with four late model P47s one day in 1947. (Inadvertent, hell. The Bearcats jumped them. What did you expect? The P47s were there.) It was no contest----partly because the Bearcat, below ten thousand feet, could do absolutely everything better than anything with a propellor and at low altitudes could out accellerate most contemporary jets.


A Bearcat below 10k? I am not sure this adds to the debate for the reasons you stated. Would a F4U-4 do better? Unknown.



> Nonetheless, our guys said that AD Skyraiders and even SB2C Helldrivers flown aggressively had at other times given them as much trouble as the P47s."


Navy pilots talking about an encounter with an Army aircraft, can you believe any other outcome would be stated? Army pilots talking about Navy aircraft are just unbelievable. I could easily believe a lightly loaded AD, with its powerful engine (although still not as powerful as the P-47N) and high lift wings could be a formidable turning dogfighter. It could turn, but couldn’t run. The SB2C is a toad and any model P-47 pilot would have to be asleep to be tested by that plane. It may be able to turn, but it was slow.



> Takeoff distance comparisons- from "America's Hundred Thousand"
> P47D-25 2540 feet
> F4U4 710 feet



And you nailed the problem.



> Page 282 AHT, P47 N performance is depicted in the curves of Graph 33. Speed performance of the N model was down five to ten mph from the P47M because the P47N was bigger and heavier with the same engine but the real difference was in climb performance which at combat power was less than that of early Thunderbolts and at military power hardly exceeded 1700 FPM up to 20000 feet.



There is a problem with this comparison. The weight comparison of the P-47M to N shows a difference of 2000 lbs. The P-47N has a basic weight of 500 lbs more than the M. Apparently the tested N had a much higher load factor than the M. When I corrected the P-47N basic weight for fuel and ammo of the F4U-4 used in AHT, the gross weight of the P-47N was13,872 lbs or 2828 lbs less than the tested aircraft in the AHT chart. Obviously, this is a significant number, almost a ton and a half, affecting both airspeed and especially climb. Using this data, I guessed the climb of the P-47N would be around 4000 ft/min, or similar but slightly less than the F4U-4. Air force test of a P-47N at a gross weight of 15,790 lbs showed a SL climb rate of 3580 ft/min. This is still almost 2000 lbs less than the P-47N adjusted to the F4U-4 weight. Airspeed impact is less and I have not corrected that value.


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## windswords (Oct 4, 2010)

_P47D-25 2540 feet
F4U4 710 feet
_
Is this a takeoff fully loaded from dry land for the Corsair? Or a carrier going 30 knots into a 30 knot headwind? Because even the Essex class carriers were 872 feet long overall. The Bolts takeoff is undoubtedly laden down with bombs rockets and drop tanks. I've seen restored examples get off the ground in much shorter distances than that.

_"There has never been a vessel long enough to launch a P-47 of any variety with a full load of fuel to take advantage of the range differential - so that would be a spurious argument." _

*Well to argue the Corsair is superior just because it was designed for carrier operations is just as spurious, which was the point I was trying to make. And this doesn't change the fact that the Bolt had a 1000 mile greater range.*

"Even the 8th AF jugs were far below the air to air ratio of the Mustang over Europe."

*I don't have those ratios but IIRC the Jug shot down more German planes than any other type - at least for the Americans. So the ratio couldn't have been that bad. A lot pilots became aces in the Bolt, including those who later switched to Mustangs.*

_"The Jug was out rolled by the Fw 190 below 350mph and the Fw 190 was about as fast"_

*Gotta keep your speed up!*

_" - the 109 out climbed (by far) and out turned below 25,000 feet."_

*Again - maneuver vs energy. I'll take energy every time.*


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## tail end charlie (Oct 4, 2010)

Colin1 said:


> Grumman Avenger
> there were two designations
> 
> TBFs were built by Grumman themselves
> TBMs were built by the Eastland Aircraft Division of GM



Thanks guys.


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## tomo pauk (Oct 5, 2010)

Hi, ren,

This:


renrich said:


> ...
> Page 106, "America's Hundred Thousand" The P47 had a two stage system with two blowers or compressors. *The first stage was driven mechchanically by the engine.* The second stage was driven by exhaust gasses. So there is mechanical bleed off.
> ...



is in collision with this:



> From Linnekin, "Eighty Knots to Mach 2" "The airplane had *a huge turbosupercharger that by a combination of drag and mechanical power bleed off* must have caused a substantial performance degradation at other than optimum altitudes.



So I'd go with AHT, and claim that mechanical bleed off is minor issue for turbocharged R-2800 vs. mech supercharged 2800 - and power charts.
Surely, the 'substantial performance degradation at other than optimum altitudes.' needs to be backed by some good numbers - for sheer power of P-47's engine Germans Japanese would've killed for in 1943-45.

Back to mr. Linnekin, while acknowledging his experience knowledge:
#1 thanks for pointing out he was naval aviator, therefore his view about P-47 need to be taken with a grain of salt - both because of inexperience about army planes, and possible bias 
#2 (again) phrase 'must have caused' is not to be expected as a view expressed by a professional


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## renrich (Oct 5, 2010)

TP, there is no doubt that Linnekin is speculating about the P47 because I feel sure he never flew one or studied one extensively. I don't think however that his statement is inaccurate, as I understand it. The first blower was driven by the crankshaft so would that not bleed off power? The P47 was a big airplane so that would cause a lot of drag, would it not? Anyway, the P47N had very good performance above 25000 feet up to something over 30000 feet. But it was not such a good performer at lower altitudes, especially below 20000 feet. Something must have caused that. The F4U4 is about 15-20 mph faster than the P47N at very low altitudes and the Thunderbolt only surpasses the Corsair in that measurement above 25000 feet. That rate of climb in military power of 1700 FPM up to 20000 feet for the P47N is indicative of something also, probably weight.

If top speed is the only determinant in the effectivenss of a fighter's performance, which it is not, the P47N only betters the F4U4 above 25000 feet. To me, if one fighter climbs better, is faster, accelerates better and is more maneuverable from sea level to 25000 feet and the other only begins to outperform the first one at 25000 feet up to around 35000 feet, my choice is clear as to which is "best." I guess that depends on your definition of best.

The P47N, as I understand it, was designed to be a long range, high altiude, escort fighter for the PTO. It sounds like it would have been good at that if the B29s were bombing from 30-35000 feet. In the event the B29s found that their very high altitude bombing was not effective so the mission of the P47N was diminished in importance.

If the question is, which is the best high altitude, long range, escort fighter, the winner is the P47N. If the question is, which is the best all around, carrier borne or land based, fighter, fighter bomber, ACM fighter at altitudes where most ACM took place and defender of the fleet, my choice would be F4U4.


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## davparlr (Oct 5, 2010)

windswords said:


> *I don't have those ratios but IIRC the Jug shot down more German planes than any other type - at least for the Americans. So the ratio couldn't have been that bad. A lot pilots became aces in the Bolt, including those who later switched to Mustangs.*



ETO Aircraft shot down by P-47s 3082, for the P-51, 4950.


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## tomo pauk (Oct 5, 2010)

Hi, ren 

I'm not advocating that P-47N was so many times better than F4U-4(it was not), merely putting out that mr. Linnekin's opinion about P-47 is only opinion (despite the credit the man deserves about other planes). Perhaps quoting some real P-47 expert would've been better choice 

Re. power bleed off: that issue is of minor weight re. P-47, since it applies much more on Merlins, DBs, Jumos, R-2800s with mech supercharging etc.
Re. drag of P-47: drag itself means nothing, if airplane has enough power to overcome it. We all know that P-47 was fastest combat-ready plane when introduced, and it's speed was always high - thanks to turbo mostly.


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## drgondog (Oct 5, 2010)

windswords said:


> _
> 
> "Even the 8th AF jugs were far below the air to air ratio of the Mustang over Europe. Ditto 9th and MTO."
> 
> ...


_

below - the build up.._


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## Shortround6 (Oct 5, 2010)

renrich said:


> TP, there is no doubt that Linnekin is speculating about the P47 because I feel sure he never flew one or studied one extensively. I don't think however that his statement is inaccurate, as I understand it. The first blower was driven by the crankshaft so would that not bleed off power?



Why would it bleed off any more power than the first blower on the F4U which was also driven by the crankshaft? I believe both engines used the same impeller in the first blower which was geared up 7.29:1 in the P-47 and 7.50:1 in the F4U-4.




renrich said:


> The P47 was a big airplane so that would cause a lot of drag, would it not?



Perhaps not as much as is commonly thought. America's Hundred thousand gives a drag co-efficient of .0213 for the P-47B (no number of the P-47N) vs .0267 for the F4U-1D (no number given for the F4U-4) for profile drag flat plate areas of 6.39 sq.ft. for the P-47 vs 8.58 sq.ft. for the F4D-1D. Granted profile drag is not the only drag component acting on a flying airplane but perhaps the P-47 wasn't quite as draggy as most people believe? Or the book is in error?





renrich said:


> Anyway, the P47N had very good performance above 25000 feet up to something over 30000 feet. But it was not such a good performer at lower altitudes, especially below 20000 feet. Something must have caused that. The F4U4 is about 15-20 mph faster than the P47N at very low altitudes and the Thunderbolt only surpasses the Corsair in that measurement above 25000 feet. That rate of climb in military power of 1700 FPM up to 20000 feet for the P47N is indicative of something also, probably weight.



I would note that the performance figures in "America's Hundred Thousand" give weights. The P-47N's weight is about 2 tons heavier than the F4U-4. This is certainly going to affect things like climb. 
I would note that the weights for the P-47N show that while it weighed only 736lbs more than a late model "D" in basic condition ( trapped fuel and oil plus guns) it's performance numbers were taken at a weight 2200lbs heavier than the "D" model performance numbers. 
Given that the P-47N will hold 556 US gallons of gas in internal tanks comparing it's performance with full tanks to an F4U-4 holding only 234 US gallons of fuel is going to give the F4U-4 an advantage. dumping 330 gals out of the P-47N should lighten it up by about a ton and show rather different performance figures in some cases.


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## windswords (Oct 5, 2010)

drgondog,

Thanks for posting that document. Do you have the same figures for the 9th AF? The 15th and 12th AF's?


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## renrich (Oct 5, 2010)

No doubt that the P47N carried a lot of fuel and I think had a bigger wing, to carry that fuel. If the P47N carries only the same internal fuel as the F4U4 then it will weigh less and climb faster. But then it won't have the range which is partly the reason for the bigger wing. Even the P47M which was the limited production buzz bomb chaser and had the same engine as the N model could not better the F4U4's climb performance or low altitude Vmax and was no faster at 25000 feet. I don't have figures for a low weight P47N but must believe that they would not be quite as good as the M model because of higher empty weight and a bigger wing, I think, which contributes to more drag.

I think the drag coefficients given in AHT are correct and that lower DC of the P47 is the result of a smaller wing with a different shape (thinner). Those undoubtedly are the reasons why, along with the high weight, the P47 was such a ground lover.

Vought put together an F4U with trubocharged engine but decided the trade offs were not worth it and opted for a bigger supercharger in the ultimate performing Corsair, the F4U5.

TP, I am only quoting Linnekin and my uncle because they both seemed to have knowledge about the performance of the P47 in mock dogfights against Bearcats and Corsairs. I also seem to recall reading in Tom Blackburn's book, "The Jolly Rogers" that he and other members of his squadron, flying F4U1s, bounced P47s on the east coast in late 1942 and had their way with them. The guys in the P47s, as I recall, kept trying to get the Corsair drivers to get up high with them but the Navy guys sensibly declined.


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## drgondog (Oct 5, 2010)

windswords said:


> drgondog,
> 
> Thanks for posting that document. Do you have the same figures for the 9th AF? The 15th and 12th AF's?



No - all WIP.. I have the 354th in the 9th and all the awards for all 9th AF groups but I don't yet have a good source for losses other than 354FG


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## davparlr (Oct 5, 2010)

Shortround6 said:


> Perhaps not as much as is commonly thought. America's Hundred thousand gives a drag co-efficient of .0213 for the P-47B (no number of the P-47N) vs .0267 for the F4U-1D (no number given for the F4U-4) for profile drag flat plate areas of 6.39 sq.ft. for the P-47 vs 8.58 sq.ft. for the F4D-1D. Granted profile drag is not the only drag component acting on a flying airplane but perhaps the P-47 wasn't quite as draggy as most people believe? Or the book is in error?



I have seen that data also, but I have a problem with it. When I compare the P-47 to the F4U airspeed at SL and equivalent HP, whether it is the P-47B vs. the F4U-1 or the P-47D-25 vs. F4U-4, both cases having equivalent combat HP at SL, the F4U always comes out on top. In my mind, this is a very good indication of the airframe efficiency. In this case, it a appears that the F4U is a more efficient air vehicle implementation than the P-47. Tis a puzzlement. This, of course, does not negate the performance arguments I have previously presented.


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## VG-33 (Oct 6, 2010)

> I have seen that data also, but I have a problem with it. When I compare the P-47 to the F4U airspeed at SL and equivalent HP, whether it is the P-47B vs. the F4U-1 or the P-47D-25 vs. F4U-4, both cases having equivalent combat HP at SL, the F4U always comes out on top. In my mind, this is a very good indication of the airframe efficiency. In this case, it a appears that the F4U is a more efficient air vehicle implementation than the P-47. Tis a puzzlement. This, of course, does not negate the performance arguments I have previously presented.



The Cd is never a constant parameter, it depends on your flight regime (power, hight, weight).
The best airframe efficiency with an R-2800 is certainly obtained by a Polikarpov I-185/185, then by Bearcat, not by P-47 or F4U. They were to big and heavy for that.

The P-47 had a very long fuselage, but it was incorporating a turbocharer in it, and it was working well unlike for soviet TK-1 or german turbos, almost because exhaust gazes were previously cooled and smoothed. All that was needing place (size, dimensions) cause the turbo was far away from exhaust holes. Soviet TK-1's were working on very hard conditions (extreme heat, pressure strikes), that explains their failure, despite more advanced steels used.

But even the I-185/187 should have been able to win every simulated fight, aerobatic contest and pylone race, it was a 100% useless fighter for ETO, MTO, PTO due to its short range, and even for America's defense except if the country was invaded*. It was not able to carry roomy extra devices for night and bad weather flights either and moreover locators.

* Some things should have been done, before that, and the I-185 was unable to do them, unlike P-47's and F 4U's...

Back to America in 1940, there were no prouves that stategic and stratospheric "Americabombers" of B-29 class were not to be developped in Germany, Italy, Japan, SU, and worse from all of them altogether...
Imagine USAF nightmares. I can perfectly understand high-altitude fighter request, even at size an weight coast.

That means, a fighter is:

-a weapon
-a tool in the global defence structure.

The best fighter in a "show" is not always the best in the real life.

To resume, i'm not sure that F4U was a "better" plane than the P-47 even if was as fast and could oufight it, both in vertical and horizontal plans, from that point of view.


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## drgondog (Oct 6, 2010)

Shortround6 said:


> Why would it bleed off any more power than the first blower on the F4U which was also driven by the crankshaft? I believe both engines used the same impeller in the first blower which was geared up 7.29:1 in the P-47 and 7.50:1 in the F4U-4.
> 
> .



The flat plate drag for the 51B/D was around 4.65 sq ft at 330mph and 15,000 feet IIRC..

VG-33 was entirely correct that drag figures must be calculated, used and compared at same Reynolds number..


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## renrich (Oct 6, 2010)

Dav, it is puzzling to me also about the less than sterling performance of the late P47s, especially those with 2800 HP at lower altitudes. Perhaps that performance issue was the result of the same forces that made the F2G Corsair with 3000 HP very little faster than the F4U4 at low altitudes. I have read that at some point adding HP to an airplane only results in better load carrying ability but no speed gain. Maybe it is propellor efficiency?


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## VG-33 (Oct 6, 2010)

renrich said:


> Dav, it is puzzling to me also about the less than sterling performance of the late P47s, especially those with 2800 HP at lower altitudes. Perhaps that performance issue was the result of the same forces that made the F2G Corsair with 3000 HP very little faster than the F4U4 at low altitudes. I have read that at some point adding HP to an airplane only results in better load carrying ability but no speed gain. Maybe it is propellor efficiency?



For trains and cars it's very simple, the speed increase is proportional to the power cubic root. So for 3% speed increase you need 3 x 3 x3 =27 % power increase. For the plane it's the same, except that for the same wing loading at same AoA your plane is climbing because of the lift increase! 

So you reduce your AoA to stay at the same level, and gain some induced drag decrease. Each case being particular, your f=Cl/Cd plays a major rule on your polar point. It means: for the same power X% increase, Mustang gains proportionaly more Y% speed than a Gladiator!

All that does not work about Mach =0,7, since classical prop and wing profiles are quickly loosing properties.
So independently of your power in excess you wouldn' fly much quicker, cause your prop/wing output would be seriously reduced!


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## Colin1 (Oct 6, 2010)

VG-33 said:


> All that does not work about Mach =0,7, since classical prop and wing profiles are quickly loosing properties.
> So independently of your power in excess you wouldn' fly much quicker, cause your prop/wing output would be seriously reduced!


I guess that loosely translates to the closer you are to the edge of the envelope (for a piston-engined fighter) more bhp will have less significance


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## Ivan1GFP (Oct 6, 2010)

Regarding the F4U-4 being faster than the P-47N down low, I have always wondered exactly why the maximum speed of the F4U-1, -1A, -1D range from about 390 mph max to 417 mph max. I haven't seen a quote for a P-47 up to P-47D below 400 mph and most are around 430 mph or so. There doesn't seem to be the same variation with the P-47.

BTW, Regarding roll rates, I remember reading in the Motorbooks "Warbird Buyer's Guide" that while the absolute maximum roll rate of the P-47 wasn't extremely high, it wasn't bad and it doesn't lose much under G load while many other fighters lose a large percentage of their roll rate when pulling G as you would in a dogfight. In the same book, the P-47 rated nearly the same as the P-51D in turning ability. The P-51D was slightly better, but the P-47 made up for it by being more controllable.

This is just minorly off topic: Does anyone here have profiles / schematics with dimensions for the P-47D and P-47M or N models? I am curious as to what differences there are because the later models always looked larger to me but I can't quite pin down exactly where.

Thanks.
- Ivan.


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## Colin1 (Oct 6, 2010)

Ivan1GFP said:


> This is just minorly off topic: Does anyone here have profiles / schematics with dimensions for the P-47D and P-47M or N models? I am curious as to what differences there are because the later models always looked larger to me but I can't quite pin down exactly where


Not schematics exactly

The P-47D, M and N


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## davparlr (Oct 6, 2010)

renrich said:


> Dav, it is puzzling to me also about the less than sterling performance of the late P47s, especially those with 2800 HP at lower altitudes. Perhaps that performance issue was the result of the same forces that made the F2G Corsair with 3000 HP very little faster than the F4U4 at low altitudes. I have read that at some point adding HP to an airplane only results in better load carrying ability but no speed gain. Maybe it is propellor efficiency?



I am not sure the increase hp of the late model P-47s were not as productive as the early models. The P-47B, with 2000 hp was capable of 334 mph at SL, while the P-47M, with 2600 hp was capable of 367 mph. I think this is similar to the F4U-1, with 2000 hp is capable of 340 mph at SL and the F4U-4, with 2380 is capable of 380 mph.


The F2G performance always baffled me. However, I think the answer is in its primary design goal and the associated compressor design. I believe the F2G was designed for low level performance, possibly as reported for attacking Kamikazes, and lacked a good high altitude compressor. Its SL speed is quite impressive, nearly 400 mph, about 25 mph faster than the F4U-4. I think this is reasonable since the F2G at 3000 hp had 620 hp more than the F4U-4 at 2380 hp. Its top speed is 431 at only 16,400 ft. compared to the F4U-4’s 446 mph at 31,400 ft. The XP-72 with the same, but slightly more powerful, engine was capable of an amazing 490 mph at 25,000 ft. So, I think it had the power to really perform, but it was basically, geared down to fight in the dirt. I would guess that it would be faster than the F4U-4 up to about 10K.


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## renrich (Oct 7, 2010)

Would not the XP72, if it had gone into production, be more contemporaneous with the F4U5? I believe it was capable, at critical altiude of around 470 mph.

Thanks to Colin for posting the info on the P47s above. To me the significant aspects of those numbers is that they appear, (although I am sure they are not intended to) to show that the maximum performance numbers all occur at the same time. For instance it says that the P47N took 13.5 minutes to climb to 32000 feet, carried 570 gallons of internal fuel, had a maximum range of 920 miles and had either eight or six mgs with either 425 or 267 rounds per gun. Most of us look at those figures and say, "wow." My bet is that when the N climbed to 32000 feet in 13.5 minutes it did not carry 570 gallons of fuel and had only six mgs with only 267 rounds. This is the problem with all our comparisons of performance numbers on all the aircraft we talk about. It is fun to throw around these numbers but they often are misleading.

The F8F was an impressive airplane when it first came out. It could climb like a homesick angel and at low altitudes could outdo almost any other fighter in existence. As the airplane evolved( for instance going from four 50 cals to four 20 mms, getting a taller vertical stabilizer and some engine mods) it's performance deteriorated some but it was deployed on all the Essex type carriers. The Corsair was deployed on the Midway types. The Bearcat must have been the apex of piston engined carrier fighters, on paper. However, in around 1948, the Bearcats were pulled off the carriers and relegated to reserve units and the Corsairs were the fleet fighter. The reason was that the Bearcat could not carry the ordnance the Corsair could and the Corsair was overall just as good as a pure fighter. All those gaudy performance figures that look so good on paper that us "armchair experts" write so knowingly about don't always tell the whole story.


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## davparlr (Oct 7, 2010)

renrich said:


> Would not the XP72, if it had gone into production, be more contemporaneous with the F4U5? I believe it was capable, at critical altiude of around 470 mph.



The XP-72 was actually a contemporary of the F2G. First flight of the XP-72 was in February of 1944, which I believe is before the first flight of the F2G. Testing was impressive, although one was lost, I believe when a turbocharger blew. The AAF ordered 100 to be built but cancelled the order when the need was not established and emphasis was put on jets. U.S. Air Force Museum records the top speed of 490 mph, other sources show 480 mph. I do not know the turbo profile of the XP-72, but if it was the same as the P-47D and M/N, the XP-72 would be generating nearly 3500 hp at 33k ft., around three times the power generated by the highly esteemed Ta-152H. With this power the XP-72 could probably go as fast as a piston powered, propeller driven, fighter could go. The AAF had a powerful fighter on the back burner in 1944 that could have addressed any of the advanced propeller driven aircraft the Axis were developing.



> Thanks to Colin for posting the info on the P47s above. To me the significant aspects of those numbers is that they appear, (although I am sure they are not intended to) to show that the maximum performance numbers all occur at the same time. For instance it says that the P47N took 13.5 minutes to climb to 32000 feet, carried 570 gallons of internal fuel, had a maximum range of 920 miles and had either eight or six mgs with either 425 or 267 rounds per gun. Most of us look at those figures and say, "wow." My bet is that when the N climbed to 32000 feet in 13.5 minutes it did not carry 570 gallons of fuel and had only six mgs with only 267 rounds. This is the problem with all our comparisons of performance numbers on all the aircraft we talk about. It is fun to throw around these numbers but they often are misleading.



You are right about the data. It probably came from several sources that were not related. Those time to climb numbers seem to be at a lighter weight, probably about the weight of the calculation I did, or around 13,800 lbs or lighter for the N. 



> All those gaudy performance figures that look so good on paper that us "armchair experts" write so knowingly about don't always tell the whole story.



Excellent analysis.


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## Colin1 (Oct 7, 2010)

davparlr said:


> You are right about the data. It probably came from several sources that were not related


A curious remark
how definitely is probably? I've never considered Roger Freeman to be anything other than a reliable source


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## Colin1 (Oct 7, 2010)

The XP-72 was the ultimate in Thunderbolt development. When fully developed its 3,000hp radial was expected to give the aircraft top speed of over 500mph. The lower picture is of the second aircraft with an Aero Products contra-rotating propeller. _(Republic)_


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## drgondog (Oct 7, 2010)

Colin1 said:


> A curious remark
> how definitely is probably? I've never considered Roger Freeman to be anything other than a reliable source



Roger was very good - but the scope of his research was unsupported by the readily available resources now available to support his 8th AF histories. His works had errors - which I can relate to Colin (as you may have gathered from some of my annotated remarks in ABD) - I am STILL making corrections to the new book.

For example USAF 85 was not available to him, nor Frank Olynyk's exhaustive research on victory credits which have resulted in the now current updates at USAFHRC's Victory Credits for USAAF/USAF.

I wish I was a lot younger. I was going to do a joint collaboration w/Jeff Ethell to do the 'Opus' of 8th Fighter Command but he screwed it up when he stalled that P-38 on final.. good guy. I had known him from time his father was a squadron CO when dad had the 35th FBW and we were all in Japan together from 1948 to the time he passed on us.

Researching ONE fighter group thoroughly is a major undertaking - doing 15 plus the Scouts would have been a lot of work - actually double because we agreed to 'audit' each other's research.


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## renrich (Oct 7, 2010)

Don't know where to post this but guess I will here. Played golf today at Antelope Hills muny here in Prescott, AZ. The two courses there are next to the airport. Teed off on number one of the south course about 12:00 noon. Was ready to hit my second shot on the par five when I heard the sound of a big round engine. Looked toward the airport and here came one after the other two F6F Hellcats. They were both in the Navy blue color and after coming off the runway, climbed steeply and made a left turn to the North. I have seen Hellcats in a static display and one flying at an airshow but don't recall ever seeing two together at once. Quite a thrill and I expect I will never see the like again. Wonder how many Hellcats are still flying?


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## davparlr (Oct 7, 2010)

renrich said:


> Don't know where to post this but guess I will here. Played golf today at Antelope Hills muny here in Prescott, AZ. The two courses there are next to the airport. Teed off on number one of the south course about 12:00 noon. Was ready to hit my second shot on the par five when I heard the sound of a big round engine. Looked toward the airport and here came one after the other two F6F Hellcats. They were both in the Navy blue color and after coming off the runway, climbed steeply and made a left turn to the North. I have seen Hellcats in a static display and one flying at an airshow but don't recall ever seeing two together at once. Quite a thrill and I expect I will never see the like again. Wonder how many Hellcats are still flying?



It is always a thrill to see some of the old birds flying when you don't expect it. You should try to get to the Chino airshow in the spring. Last year, 2009, they had Grumman planes flying. You would have love it.

As for golf and aircraft, I was golfing the other day at Victoria course in Carson, Ca. and right over us the Goodyear Blimp came in for landing. I could have chipped up to hit it. Its landing field is right next to the hole. I remember seeing a blimp in the 50s at Pensacola NAS when I was a kid.


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## Colin1 (Oct 8, 2010)

renrich said:


> Wonder how many Hellcats are still flying?


As of 2000
there are (were) 23 extant F6Fs

9 airworthy
14 static display incl 1 replica and a composite

all 9 in the same airspace would be a spectacle, the drone of 9 R-2800s in formation... 8)

I don't have any information any more up to date than that


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## KevinK. (Oct 8, 2010)

Well, I've read about 2/3's the pages here, and skimmed the rest. 

They both seem very close in combat. Again, High alt, vs. low-mid alt. I think it becomes more pilot skill which determines who is better. Or maybe it's more preference for the pilots. 

How about looking at kill ratio's? 
Near the end of the war they both faced fewer and fewer targets and got to do more and more ground attack roles. Looking at the the posting by Colin1, it shows the P-47N having a bomb load of 3000 lbs. Didn't the F4U-4 carry a larger payload of 4,000 lbs?

The F4U was a much cooler looking plane. It even had a TV show about it! Can't get much better than that. 

Btw.. the XP-72, looks like a fat and rolly-polly P-51. 

Great reading guys!

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## renrich (Oct 8, 2010)

Thanks Colin. The three guys I was playing with, of course, hadn't a clue about what they were seeing, so I had to educate them,  I was guessing that about twenty were air worthy and I told them that they were seeing perhaps ten per cent of the Hellcats left in the world that could still fly. Had no idea it was closer to twenty per cent. Speaking of engines, the second one that took off had an engine which sounded different from the first. A litle less staccato or more muffled. Perhaps one was an F6F3 and the other an F6F5? I am still marveling at seeing two together at once, considering how few are left.


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## syscom3 (Oct 8, 2010)

Colin1 said:


> As of 2000
> there are (were) 23 extant F6Fs
> 
> 9 airworthy
> ...



Last year at Chino, we had a bunch of Grummans up in the air.


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## Colin1 (Oct 8, 2010)

syscom3 said:


> Last year at Chino, we had a bunch of Grummans up in the air.


A bunch of any Grummans works for me
How many were F6Fs though?


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## Colin1 (Oct 9, 2010)

drgondog said:


> I was going to do a joint collaboration w/Jeff Ethell to do the 'Opus' of 8th Fighter Command but he screwed it up when he stalled that P-38 on final.. good guy. I had known him from time his father was a squadron CO when dad had the 35th FBW and we were all in Japan together from 1948 to the time he passed on us.


Bill
I think Roger reported on data that he did have access to, at least, in the texts of his that I own. I understand your concern with error, it is the unwelcome bedfellow to any form of complex research.

Jeff Ethell, as I recall, had a father on P-38s and like you with your own father, he completed some works on the P-38. He was an accomplished pilot in his own right, became an ordained minister and though I don't now recall the year of his flying accident, was saddened by his passing.


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## renrich (Oct 9, 2010)

Colin, I was not saying the data you posted on the P47s was in error but rather that many people, including myself in the past, will look at data and take the extremes and think they all happen at the same time. An Example: off the top of my head---F4U4, Vmax- 446 mph, rate of climb- 3800 feet per minute, max bomb load-4000 pounds, max range with external fuel 1500 miles. Wow, that is a winner and I am impressed and what fighter in WW2 could do better?

Not so fast. An F4U4 can't climb at 3800 FPM with external tanks or go 446 MPH either. That 446 MPH is clean and only at it's critical altitude. And the 3800 FPM is only at sea level or so. Much less with a 4000 pound bomb load and I am not sure if anybody except Lindberg actually flew a mission in WW2 in a Corsair with a 4000 pound bomb load and he probably only flew a hundred or so miles with it.


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## Colin1 (Oct 9, 2010)

renrich said:


> Colin, I was not saying the data you posted on the P47s was in error but rather that many people, including myself in the past, will look at data and take the extremes and think they all happen at the same time. An Example: off the top of my head---F4U4, Vmax- 446 mph, rate of climb- 3800 feet per minute, max bomb load-4000 pounds, max range with external fuel 1500 miles. Wow, that is a winner and I am impressed and what fighter in WW2 could do better?
> 
> Not so fast. An F4U4 can't climb at 3800 FPM with external tanks or go 446 MPH either. That 446 MPH is clean and only at it's critical altitude. And the 3800 FPM is only at sea level or so. Much less with a 4000 pound bomb load and I am not sure if anybody except Lindberg actually flew a mission in WW2 in a Corsair with a 4000 pound bomb load and he probably only flew a hundred or so miles with it.


Ren
not a problem, you're entitled to disagree where you see fit but I thought I understood your response anyway. My guess would be that each performance figure is attained with the a/c optimised for best performance in that measurement category ie as you say, rate of climb measured with a/c NOT strapped to a 4,000lb bomb...

Dav's response mystified me a bit with no qualifier for said response


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## syscom3 (Oct 9, 2010)

Colin1 said:


> A bunch of any Grummans works for me
> How many were F6Fs though?



I'm going to say three.


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## renrich (Feb 3, 2012)

I had an uncle who was an instructor pilot in the AAF in WW2. He flew P39s and P47s and probably others. He said that when they went to the gulf coast to pracitse gunnery in P47s they would often meet Corsairs im mock dogfights and had no chance. Now I am sure this was at low altitudes. Depending on the model, the Corsair was at it's best up tp to 20000- 25000 feet. Above that altitude the P47 would begin to establish supremacy. Richard Linnnekin in " 80 Knots to Mach Two" stated that a well handled SB2C could hold its own with a P47 at low altitudes.The WW2 Corsair was designed to have max performance below 25000 feet and the P47 above that. My guess is that of all ACM that took place in WW2, ETO or PTO, the majority was under 25000 feet. It seems to me that if I was the Czar of fighters for any country and could only pick one fighter to produce and I had to choose betwen one that was superb from SL to 25000 feet and only so so above that or one that was so so from SL to 25000 feet and superb from 25000 to 30000 plus, my choice would be simple.


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## Dcazz7606 (Feb 3, 2012)

I believe I read that there was a lot of tack welding on the skin of the Corsair as opposed to screws on the P-47. This could account for a stronger joining of the frame to the skin As I recall the article chance-Vought pioneered this method. can't remember the publication though.


Sal Monella said:


> I believe the skin on the Thunderbolt was thicker than on the Corsair. Didn't the Corsair have some fabric covered surfaces?


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## Dcazz7606 (Feb 3, 2012)

It's possible they measured a D with a Hamilton Standard prop and the N with the curtis Electric.


JonJGoldberg said:


> Reply to Sal Monella >>>
> There was a slight difference.
> Combat weight: Suppose for the moment we change 47 to 51 so that it is now a P-51D against a P-47N. Using your argument (of both aircraft fulfillng the same role, you would not use a far larger and heavier fuel load in only one aircraft and since it would be impossible to load up the "D" with internal fuel to match the "N", you must do the reverse or reduce the internal fuel load of the "N" to match the "D".) you feel it fair to apply yet another advantage to the ’47N. I think not. Rather start at combat weight. Too much fuel, OK, the lets put both fighters at 50% fuel. This to me seems more rational, fair.
> 
> ...


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## FLYBOYJ (Feb 3, 2012)

Dcazz - you realize you answered 6 year old posts?!?

You are right about the welding though - it was actually spot welding and it was also done on the Kingfisher.


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## Dcazz7606 (Feb 4, 2012)

You know, I didn't even look! Lol! I just love the p-47 and saw a couple of points I could add to! Lol!


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## davparlr (Feb 4, 2012)

FLYBOYJ said:


> Dcazz - you realize you answered 6 year old posts?!?
> 
> You are right about the welding though - it was actually spot welding and it was also done on the Kingfisher.



Do you realize we are getting old!!!!


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## drgondog (Feb 4, 2012)

Colin1 said:


> Bill
> I think Roger reported on data that he did have access to, at least, in the texts of his that I own. I understand your concern with error, it is the unwelcome bedfellow to any form of complex research.
> 
> Jeff Ethell, as I recall, had a father on P-38s and like you with your own father, he completed some works on the P-38. He was an accomplished pilot in his own right, became an ordained minister and though I don't now recall the year of his flying accident, was saddened by his passing.



Irv Ethell was a squadron CO in the 35th FBW post war in Japan when my father commanded the Group - which is how the Ethell's and the Marshall's connected. I don't know if Irv flew 38s in WWII or whether he was with 35th when it moved to Japan - The 35th started in P-39s, went to 38's and converted to 47s in mid 1943, then 51s in March 45 - and stayed with them until F-84s in 1952.

As to errors - I have no criticism for Freeman. I know how much research and cross correlation goes into just one Group history in the 8th AF. It is a little easier today, but doing a group by group detailed history of just 8th FC is an awesome task for two people if you dive into a/c serial numbers/crew assignments. And then there is the commercial 'thingy'. I wanted deep dive, Jeff wanted "Escort to Berlin" detail so we weren't far off but so many Group/Squadron Histories were 'spotty' in contrast to 4th and 355th.


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## drgondog (Feb 4, 2012)

Dcazz7606 said:


> I believe I read that there was a lot of tack welding on the skin of the Corsair as opposed to screws on the P-47. This could account for a stronger joining of the frame to the skin As I recall the article chance-Vought pioneered this method. can't remember the publication though.



If tack welding on skin was common, it could not have been performed for panel load shear transfer... rivet to bulkhead and beam has very predictible and sound engineering principles behind the approach - as well as better opportunity for QA/inspection. Spacing and shank thickness has to be uniform and matched to both the shear capability of the skin and well as individual shear capability for the rivet. Welding skin on the aerodynamic surface skin of an airplane would be a nightmare on a production line.

Secondly - it had to be out of the boundary layer - else create unneccesary drag compared to flush riveting and require enormous labor to grind ...perhaps internal application of welding?

Last - either welding steel (say for engine truss/beam), or 6064 type aluminum - which is way below 2024 for strength.


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## FLYBOYJ (Feb 4, 2012)

Dcazz7606 said:


> You know, I didn't even look! Lol! I just love the p-47 and saw a couple of points I could add to! Lol!


 No worries!


davparlr said:


> Do you realize we are getting old!!!!





drgondog said:


> If tack welding on skin was common, it could not have been performed for panel load shear transfer... rivet to bulkhead and beam has very predictible and sound engineering principles behind the approach - as well as better opportunity for QA/inspection. Spacing and shank thickness has to be uniform and matched to both the shear capability of the skin and well as individual shear capability for the rivet. Welding skin on the aerodynamic surface skin of an airplane would be a nightmare on a production line.
> 
> Secondly - it had to be out of the boundary layer - else create unneccesary drag compared to flush riveting and require enormous labor to grind ...perhaps internal application of welding?
> 
> Last - either welding steel (say for engine truss/beam), or 6064 type aluminum - which is way below 2024 for strength.



All true Bill - if I remember most of the spot welding was accomplished in portions of the airframe that was taking a direct load. I believe in some cases the spot welding was later reinforced with rivets outside the welded areas. When I was in A&P school I had to write a 100 page report about welding, I remember using this as "filler"


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## Barrett (Oct 17, 2013)

Actually, the Jug's eight .50s to the Corsair's six was not a factor. Combat experience showed that in Europe, and especially in the Pacific, four M2 Brownings was the optimum armament. It's why the FM-2 "Wilder Wildcat reverted to the four guns of the early F4F-3. Six .50s in the dash four Wildcat meant a lot less trigger time.


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## USS Enterprise CV-6 (Mar 31, 2014)

The Corsair and the P-47N were 2 of the best planes in WW2. If they were attacking each other the Corsair could get behind it and tear open the P-47s canopy. I would choose Corsair for the better fighter and fighter bomber, but P-47N for ground attack.


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## windswords (Apr 2, 2014)

1. High altitude speed - P-47
2. Low altitude speed - F4U
3. High altitude performance - P47
4. Firepower - P-47
5. Low altitude performance - F4U
6. Turn - F4U
7. Roll - P-47?
8. Dive - P-47
9. Ruggedness - P-47

Assuming this is a 1 to 1 combat (with "clean" aircraft, no bombs, rockets etc.) Then the altitude is the big factor. Up high (25k feet +) the Thunderbolt has the clear advantage. Below 20k, it's the Corsair. At 20 - 25k I don't know. At any altitude, if the P-47 does not engage in the classic dogfight, it should do well. Turn and climb were not the most important aspects of fighter aircraft in WWII. If they were, then the A6M and Ki-43 would have been the best fighters of the war.

*IF *the pilots were of equal skill and they knew what their planes could *and* could not do, then I would give the advantage to the Thunderbolt. If the P-47 pilot is foolish enough to dogfight with the F4U then the result would be the same as if he would dogfight a Spitfire or a Zero.

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## BiffF15 (Apr 2, 2014)

Concour.

Cheers,
Biff


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## Dawncaster (Apr 2, 2014)

F4U-4 with 234gal fuel curve from SAC (use clean condition, +8kn at S.L and +10kn at 20600ft) http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf
P-47M with 205gal fuel curve from Report No. ES-300 http://www.wwiiaircraftperformance.org/p-47/p-47m-republic-wepchart.jpg
P-47N with 205gal fuel curve from Report No. ES-302-A http://www.wwiiaircraftperformance.org/p-47/p-47n-republic-wep.jpg
P-47N with 570gal fuel curve from Comparison of P-47D, P-47M and P-47N Performance http://www.wwiiaircraftperformance.org/p-47/p47m-n-speed.jpg

F4U-4's full internal fuel capacity is 234gal
P-47M's full internal fuel capacity is 370gal
P-47N's full internal fuel capacity is 570gal


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## mig-31bm (Apr 2, 2014)

Dawncaster said:


> View attachment 258287
> 
> 
> F4U-4 with 234gal fuel curve from SAC (use clean condition, +8kn at S.L and +10kn at 20600ft) http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf
> ...


was the p-47N able to use 90 in Hg fuel ? , it seem that p-47n is quite inferior except at very high altitude 
btw iam quite suprise that at about 21000 feet the F4u-4 was actually as fast as a clean P-51H ( no rack ) even though it look alot draggier with the nose


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## tomo pauk (Apr 2, 2014)

The maximum manifold pressure both for the P-51M and -N was 72 in Hg, available both by use of water-methanol injection and at least 115/145 fuel.

Dawncaster,

Are the graph values for the P-47s with or without racks?


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## mig-31bm (Apr 2, 2014)

tomo pauk said:


> The maximum manifold pressure both for the *P-51M and -N* was 72 in Hg, available both by use of water-methanol injection and at least 115/145 fuel.
> 
> Dawncaster,
> 
> Are the graph values for the P-47s with or without racks?



you mean p-47M ?


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## tomo pauk (Apr 2, 2014)

Both -M and -N; they used the same engine during the war.


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## Dawncaster (Apr 2, 2014)

tomo pauk said:


> The maximum manifold pressure both for the P-51M and -N was 72 in Hg, available both by use of water-methanol injection and at least 115/145 fuel.
> 
> Dawncaster,
> 
> Are the graph values for the P-47s with or without racks?



in my opinion, 1,2 clean, 3 had x2 wing racks

1, P-47M with 205gal fuel, Report No. ES-300 use "Design Useful Load" 
2, P-47N with 205gal fuel, Report No. ES-302-A use "normal gross weight with normal load"
3, P-47N with 570gal fuel, Comparison of P-47D, P-47M and P-47N use "combat condition"

here is later F-47N SAC

http://www.alternatewars.com/SAC/F-47N_Thunderbolt_SAC_-_17_May_1950.pdf

max speed is 385kn at 35000ft, gross weight 17228lb.

graph labelled "clean" but mission profile said take-off with three drop tanks at 20837lb, so 385kn is maximum speed with x3 racks.

and power rating is 2800BHP at critical altitude with 100/130 fuel, 115/145 fuel is not required for 2800BHP.

here is pratt whitney aircraft engines model designations and characteristics.










R-2800-57, -73, -77, -81 use 100/130 fuel.

in my opinion, R-2800 + turbocharger can handle 3000BHP with 115/145 fuel. 

here is F4U-3 october 44 test.














3000BHP with 73" hg at 28000ft.
2800BHP with 68" hg at 30000ft.
2600BHP with 63" hg at 33000ft.

I'm not sure that F4U-3 use 115/145 fuel, but in same test F4U-4 use 115/145 fuel with 70" hg at 2650BHP.






so, if P-47M/N can use 115/145 fuel, handle around 3000BHP and better performance. I think.

but I'm not sure P-47M/N use 115/145 fuel with higher than 72" hg.


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## tomo pauk (Apr 3, 2014)

Thanks for setting me straight re. fuel PN rating used on the P-47M/N.

IMO, most of the extra performance in the war emergency rating of the quoted F4U-4 seem to be emanating from using the 115/145 fuel. Such fuel is specified in the document you've linked (http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf). The altitude where the max speed is achieved is at ~20500 ft, against the 26000 ft for the data from 1946 (link); both for auxiliary supercharger in high gear. In low gear, the max speed is at 14000 ft for the engine using the 115/145 fuel, and at 20000 ft for the A/C from 1946 chart. While in WER, the faster A/C does not use the 'neutral' gear - there is no suitably low altitude for it, if the full boost enabled by use of 115/145 fuel and ADI? 
Unfortunately, I don't know both the date of the chart of the faster A/C and the fuel used by the 1946 A/C.

All this said still does not explain the better altitude performance of the faster A/C (ie. above 27000 ft) - anybody want to take a stab? 

Attached are the graphs, both for 1946 F4U-4 and the 'better' one, red line is the performance of the better A/C, for a more convenient comparison. Both maximum speeds are with two racks, both capped. Blue squares are speeds at SL and at 30000 ft of the P-47N with ~200 gals of fuel, the blue dots are for the -N with 556 gals, taken from above graph. Fuel is the 100/130 for the -N.


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## pbehn (Apr 3, 2014)

Corsair everytime, it was carrier based and stayed in the military after 1945, because it still had a role to play.

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## Shortround6 (Apr 3, 2014)

From Wiki;

"The USAAF Strategic Air Command had P-47 Thunderbolts in service from 1946 through 1947.

The P-47 served with the Army Air Forces (United States Air Force after 1947) until 1949, and with the Air National Guard until 1953, receiving the designation F-47 in 1948. P-47s also served as spotters for rescue aircraft such as the OA-10 Catalina and Boeing B-17H."

Republic was moving on to jets a bit better than Vaught did in 1944-47,in part due to Vaught having to use Westinghouse jet engines.


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## USS Enterprise CV-6 (Apr 3, 2014)

Shortround6 said:


> From Wiki;
> 
> "The USAAF Strategic Air Command had P-47 Thunderbolts in service from 1946 through 1947.
> 
> ...



Just saying this, F-47 doesn't sound as cool as P-47

Also you make a good point. Also, Vought is spelled V-o-u-g-h-t. Don't worry about it, not a word that's gonna be on a spelling test

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## pbehn (Apr 3, 2014)

Shortround6 said:


> From Wiki;
> 
> "The USAAF Strategic Air Command had P-47 Thunderbolts in service from 1946 through 1947.
> 
> ...




Thanks shortround but I think you get what I mean. In 1945 no military would scrap all aircraft, the pilots need to practice flying.


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## Shortround6 (Apr 3, 2014)

Not just practice, the jets were not quite ready for all round combat duty for several more years (1948?) as engine life and reliability was a bit on the short side. For some reason (some say logistics) the P-51s tended to stay in the Pacific and on/near the west coast while the P-47 equipped units tended to be in the Eastern United states. This did affect deployment to Korea.


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## Dawncaster (Apr 4, 2014)

tomo pauk said:


> Thanks for setting me straight re. fuel PN rating used on the P-47M/N.
> 
> IMO, most of the extra performance in the war emergency rating of the quoted F4U-4 seem to be emanating from using the 115/145 fuel. Such fuel is specified in the document you've linked (http://www.wwiiaircraftperformance.org/f4u/f4u-4.pdf). The altitude where the max speed is achieved is at ~20500 ft, against the 26000 ft for the data from 1946 (link); both for auxiliary supercharger in high gear. In low gear, the max speed is at 14000 ft for the engine using the 115/145 fuel, and at 20000 ft for the A/C from 1946 chart. While in WER, the faster A/C does not use the 'neutral' gear - there is no suitably low altitude for it, if the full boost enabled by use of 115/145 fuel and ADI?
> Unfortunately, I don't know both the date of the chart of the faster A/C and the fuel used by the 1946 A/C.
> ...



ACP use 100/130 fuel with 2380BHP at S.L
SAC and 1944 test use 115/145 fuel with 2650BHP at S.L

with same model engine, higher pressure = higher power but lower critical altitude.

case of F4U-1

60.2/59.8"hg, critical altitude 14300/19850ft
62.2/61.8"hg, critical altitude 13200/18800ft
63.9/63.4"hg, critical altitude 12200/17900ft

60.2"hg to 63.9"hg = +3.7"hg, + around 150BHP, critical altitude - around 2000ft.










case of F4U-3

63"hg, critical altitude 32500ft.
68"hg, critical altitude 30000ft.
73"hg, critical altitude 27500ft.

63"hg to 73"hg = +10"hg, +400BHP, critical altitude -5000ft.














case of F4U-4

70"hg with 115/145 fuel to 60"hg with 100/130ful = +10"hg, +200BHP, critical altitude -6000ft.

high blower critical altitude, 26000ft vs 20000ft = -6000ft.
low blower critical altitude, 20000ft vs 14000ft = -6000ft.

and F4U-4 wth 100/130 fuel, critical altitude of natual blower is only 1500ft. 

1500ft - 6000ft = -4500ft, lower than sea level.

so in my opinion, there is no natual blower stage needed for WEP with 115/145 fuel. 






new graph, F4U-4 60"hg added.

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## windswords (Apr 5, 2014)

pbehn said:


> Corsair everytime, it was carrier based and stayed in the military after 1945, because it still had a role to play.



The only reason it stayed in service after the war and "had a role to play" was because the navy did not have a jet fighter bomber. Once the F9F was available in numbers it took over that role, at least on carriers that could handle the load/landing speed. The P-47 was phased out because the air force had jets and the P-51's left were way cheaper to keep and maintain. Same for the P-38. 

One thing I forgot to mention was the increased range of the P-47N. If you only had land bases available, then the long legs of the N would make it preferable to the Corsair. If you have carriers it doesn't matter unless you can't get the carriers close enough to your target.


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## swampyankee (Apr 6, 2014)

P-47N vs F4U-4? Whichever one your pilots like better 

Incidentally, the USN considered the 20mm Hispano roughly three times as effective, air to air, as the 0.5 in M2, so it would be something like twice as effective as the 0.5 in M3. Also, the Corsair had some fabric covered control surfaces, not fabric covered wings. Fabric covered control surfaces are easier to balance, so they may be less prone to flutter.


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## tomo pauk (Apr 6, 2014)

If I'm not mistaking it badly, the P-47M and -N were the only aircraft that flew in combat with 3-stage compressor system. The air 1st compressed by a turbo-compressor with two compressor stages, then, once cooled via inter-cooler, compressed by 3rd impeller, this one integral with the engine. 
Comments/corrections?


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## Shortround6 (Apr 6, 2014)

I believe they were actually two stages, the turbo (one stage) fed the inter-cooler which fed the engine supercharge ( one stage-one speed).

Same set up as earlier P-47s _except_ 1. new "C" engine with much more cooling fin area per cylinder required less cooling air for the same power level or allowed more power from the same amount of cooling air. 2, engine supercharger _may_ have been modified. 3, Turbo was the CH-5 instead of earlier models with lower allowable rpm, 4 turbo control was changed.


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## Ottobon (Dec 23, 2015)

Did anybody or could anybody give any info if War Emergency Power on P-47M/Ns reduced power above about 32,000ft so that at a higher altitude military power rating was actually more efficient?

This is a long and interesting thread that may have a Engine Power vs Altitude chart for the R-2800-57(C) but with busy holidays thought it would be worth asking rather then digging through entire thread incase somebody had it onhand.


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## tomo pauk (Dec 24, 2015)

This graph might be interesting, when comparing speed on WER and military power. The WER still makes sense between 32000 and ~38500 ft, with manifold pressure steadily decreasing from 72 to 54.5 in Hg, and power from 2800 to 2100 HP. Above that the military power takes hold.

added: during the climb, the advantage of the WER diminishes at or above 30000 ft, moreso with the heavier a bit slower -N. graph; the -N was also with more wing area.


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## GregP (Dec 24, 2015)

Hi Tomo,

The second graph makes complete sense.

The first one is a bit confusing. What are the units along the vertical axis? Since the graphs look about the same, it SHOULD be altitude, but the numbers go from 0 - 100, so maybe it is hundreds of meters? But that would mean the "100" is only 32,000 feet, so I don't think so.


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## tomo pauk (Dec 24, 2015)

The graph above, left, is a bit cropped on left side. So on the right side it has marks '20', '30' and '40', among other, meaning 20000, 30000 and 40000 ft respectively.

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## GregP (Dec 24, 2015)

I saw the hand-written number on the right, but was just wondering what the number on the left meant. I'll just take the charts as you intended, and thanks, Tomo.


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## bentwings (Feb 10, 2021)

Flyin through trees. Nice but how about the Corsair guy that got two kills by chopping the tail off of the enemy with the prop. Not that a jug could do that just as well. The guy got a hero,medal...
msny years ago someone dug up a military test of all the popular fighters. They had prime examples of each. They were all put through their paces for a week of testing. Only the Corsair was still flyable at the end.
I build and fly rc scale models over the years I’ve seen a number of various nice scale models. Just check8ng the actual scale size and comparing only the same factor to my Corsair. It was faster by far as judged by other flyers. Turned and tacitlynflown was good enough to earn me ace for 5 meets first place. Yes I had kill flags. Wouldn’t you? I had the advantage being a drag car racer so I applied full scale exhaust adding slight tuning. Also sealedcontrol surfaces cleaned up cowl interior sealed control surfaces. Smooth wheel doors and other race care “tricks so maybe not technically equal but others could have done the same things I ran my motors on the ragged edge all the time and fine tuned the props but it was all cook book stuff. We’re I to do another today it would have functional oil cooler openings and larger motor but, it’s a hot rod in anybody’s book.

just imagine what it was like to go from your flat head40 Ford convert with grand total of 240 hp 3x2 barrel carbs 3/4 race cam Mallory ignition 3 spd trans Columbia two speed rear end to a 2800 hp combat aircraft with take off speed faster than your old Ford could go down hill.LOLIMAGINE OVER TAKing THE ENEMY BY 6 times your best top speed.ripping off more shots of .50 cal in one second than Bonnie and Clyde tommy guns held in an entire magazine.


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## tomo pauk (Feb 10, 2021)

<gets popcorn>


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## P-39 Expert (Feb 10, 2021)

P-39N compared to P-47M/N attached.

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## fubar57 (Feb 10, 2021)

​

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## P-39 Expert (Feb 14, 2021)

P-39 Expert said:


> P-39N compared to P-47M/N attached.


Tomo, why you no likee? Attempted humor not appreciated?


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## tomo pauk (Feb 14, 2021)

P-39 Expert said:


> Tomo, why you no likee? Attempted humor not appreciated?



I'd hate to see another thread locked down.

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## Xplodez (Sep 12, 2022)

I'm a little late to the conversation, but I prefer the P-47 in terms of looks. If I had to choose to dogfight against the other, I would get in the P-47 and do my best to tear through the F4U with my armament. After reading this thread, however, It seems as if I would have to be careful about my opponent getting behind me.

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## SaparotRob (Sep 12, 2022)

Hi there, Xplodez and welcome.

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## Admiral Beez (Sep 14, 2022)

R Leonard said:


> . . . but you could land a Corsair on a carrier.


True. P-47, not so much.






P-47 carrier capable?


Anyone knows something about this, what version of P-47 that is, when and where it happend?



ww2aircraft.net

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## Admiral Beez (Sep 14, 2022)

fubar57 said:


> View attachment 612167
> ​


Perfect! I’ll use that when needed, if you don’t mind.


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## PAT303 (Sep 15, 2022)

How would either go once they had to turn at 30,000 plus feet?, my guess both would lose altitude rapidly once combat commenced.

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## SplitRz (Sep 15, 2022)

> I'm a little late to the conversation


Whats 17 years between friends?!

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## PAT303 (Sep 15, 2022)

SplitRz said:


> Whats 17 years between friends?!


True, I'd love to see a few aces going at it at over 30,000ft in the various high altitude fighters, late mark Spitfires, Ta 152, P47M/N, the tactics would be interesting, I'd assume the Spit and Ta pilots would turn and climb, the American's would try to use their speed to boom and zoom, at least for the first pass.


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## davparlr (Sep 16, 2022)

PAT303 said:


> How would either go once they had to turn at 30,000 plus feet?, my guess both would lose altitude rapidly once combat commenced.


Not much decision 30k
Hp available at 30k *F4U-1D* 1390 * P47D-25* 2300 *910 hp advantage P-47*
*F4U-4* 1700 *P47N* 2800 *1100 hp advantage P-47*
airspeed at 30k *F4U-1D* 380 mph *P-47D-25* 420 mph *40 mph advantage P-47*
*F4U-4* 428 mph *P-47N* 464 mph *36 mph advantage P-47*
climb *F4U-1D* 1200 f/m * P-47D-25* 1650 f/m *450 f/m advantage P-47*
*F4U-4* 1600 f/m *P-47N* 2000 f/m 4*00 f/m advantage P:-47*

at lower altitude, different story

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## GregP (Sep 17, 2022)

The P-38 was no slouch at high altitudes and neither were 2-stage Spitfires. But the P-47 was at or very close to being one of the best fighters of the war above 30,000 feet. The Corsair was NEVER intended for high-altitude operations. If was a fleet defense and Naval attack fighter that operated most of the time below 20,000 feet and largely below 15,000 feet. 

I'd take the Corsair at low altitudes and the P-47 over almost anything else above 25,000 feet. In between would be a crap shoot.

The Ta 152 has been brought up as a high-altitude fighter, but they only delivered about 43 examples to the Luftwaffe, and it had a distinctly pedestrian victory-to-loss ratio (somewhere between 7 and 10 victories against 4 losses). That ratio was due more to the war situation than to any inherent flaws in the basic Ta 152 design, but the airplanes that were delivered were little more than rushed prototypes that were anything but well-developed. There was NO spare parts chain. Any Ta 152 that malfunctioned was used for parts or for major repairs if returned to flight status with other parts. When the war ended, there were exactly two Ta 152C's left operational for the entire Ta 152 series of airplanes. The Ta 152H-0 that the Smithsonian Air and Space Museum has was repaired to fly to the collection point. So, Ta 152s aren't in the mix if only due to lack of availability in general. None of the above detracts from what the Ta 152 design could have become had it been developed and mass-produced. The basic airplane was solid. It just never really had a chance. Two or three Ta 152s weren't ever going to be much good against 200 - 300+ P-51s coming down to straffe when the bombers turned around and started for home in 1945.

The Me 262 was far and away the superior airplane to the Ta 152, and 100 Me 262s were lost to Allied piston fighters against 542 victories for the jet. Even being over 100 mph faster than the competition wasn't enough against overwhelmingly superior numbers of lesser opposition.

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