P-51 vs P-47 post war

[tomo pauk]

Hi, snowmobileman,

I like the F-82, but I don't think it would really qualify. Maybe in a comparison with the F7F and Hornet. Besides, it's real-life reliability doesn't stack up well to it's performance numbers.

You mean that reliability was reducing performance numbers?

I think Allison should have been held accountable for it's lack of support for an active-duty military aircraft.

Was the AAF always flawless in it's relationship towards engine manufacturers? Was their doctrine, about what powerplant systems to purchase, alway realistic?

I wonder how many pilots died due to their lack of support?

I bet that much more pilots died because of incapability of their commanding officers.

 

[snowmobileman]

Tomo,

The engines would not produce the rated power and would foul plugs quickly, from what I recall. From what I remember reading, many times an aircraft would return on one engine due to fouled plugs. If the engines can't be made to run optimally, then they can't meet their performance goals. And Allison was on to new projects (jet engines), so couldn't support the engines they had produced with spare parts. I think this information came from the book, "Mustang Designer". I have a special interest in the F-82, due to it's service in Alaska post-war. The P-82B would have been a much better option than the F-82F G, had the U.S. been able/willing to buy the needed Merlins.

 

[vinnye]

If cost were a consideration, would the Twin Mustang not be more expensive that a Jug?
As posted earlier, the Corsair seems to be the ideal choice?
Not sure about running costs etc.

 

[tomo pauk]

Yep, I agree that Allison was focusing it's money, along with best engineers (after post-war cut backs what was left) to the jest engines. The new V-1710s would/should provide far more power, being aftercooled, with ADI etc, new fuel metering system, yet they were to be built in humble numbers, while unlikely to be exported. Not a good prospect for Allison bottom line, a reminder of the days of pre-ww2, when USAAF was either unable (= no funds) or unwilling to commit more resources on engine design production? Allison was never paid those 900000 USD AAF owned it pre-war, the AAF bargained that debt to be canceled if Allison wants to export the engines.The spare parts would need to be almost all new, too.
One wonder how good/bad would've performed the P-82 with F-28.

 

[davparlr]

This is a good question and I am sure a lot of the answers stated here played a part. Immediately after the war the military was in disorder and the future was questionable. What direction was defense going? The US was the sole owner of the a-bomb and the Soviet Union was not an enemy. Jet aircraft seemed to be the way. As such decision rationale was probably all over the map including political and financial issues.
Here's a performance chart of US aircraft available to support ground troop immediately after the war.

Per the thread, I've chosen to compare the P-47N, P-51D, and have thrown in the following, P-82E, B-26C (A-26), F4U-4, F7F-3, and the A-1. I did not include the P-51H since it is stressed to lighter levels and thus would not be the best selection for air-to-ground work.

Empty Weight (k lbs)
B-26 22.6k
F7F-3 16.k
P-82E 14
P-47N 11
A-1 10.5
F4U 9.2
P-51D 7.1
Max TO weight
B-26 37.7
F7F 25.8
P-82 24
P-47 20
A-1 18
F4U 14.6
P-51 11.6
Load Carrying Capacity (max TO weight – empty weight)
B-26 15.1*
P-82E 10*
F7F 9.8*
P-47 9
A-1 7.5
F4U 5.4
P-51 4.5
*- Two engine aircraft will require more fuel and thus impact actual weapon carrying capacity. Also, V engines in the P-51 and P-82 would be more efficient than the radial jobs.
Sea level speed (mph)
P-51 383
F4U 374
F7F 367
P-47 364
B-26 361
A-1 348
P-82 unk
Max speed
P-47 467
P-82 465
F4U 453
P-51 442
F7F 435
B-26 372
A-1 366
Max range (miles)
B-26 3270 1800 w/4k bomb
P-82 2500 normal, 2700 ferry
P-51 2300
P-47 2200
A-1 1900 w/2k bombs
F7F 1573
F4U 1560

Looking at the stats it is easy to see why the B-26 with its load carrying capacity and range played the air-to-ground game up into the Vietnam war. The P-47N looks pretty good in the single engine category being the best lifter of the lot, and having the rugged reputation that it has. It could drop nearly twice the ordnance per sortie the P-51 which could significantly reduce sortie rates. It even lifts more and flies further than the F4U. And, it will out lift the A-1 and fly similar range. I think the P-47N would have made an excellent ground attack plane, much better than the P-51.

 

[GregP]

Funny, we don't seem to have any reliability problems with the G-series engines we build. We build them to stock specs and they run just fine for years with normal maintenance. Makes me wonder since I see these things all the time (usually E's and F's) and they run quite nicely in service in P-38's, P-39's, P-40's. the odd P-63, a few Yaks, many tractors and boats, plus a few cars. We did the engine for John Rolley's Green Monster that was restored and it runs just fine, too.

Makes me wonder about the maintenance and operation of the engiens at the time. Operate them by the book and they run just fine. Stay at idle until the temps come up and change rpm gradually. It is much harder on an Allison to run it up to 57" of MAP for a few minutes and then rapidly throttle back than it is to run it at 57" for 20 minutes and gradually throttle back while allowing it to cool down easily.

Maybe they needed some instruction in how to run a piston engine in a fighter aircraft. I wonder how Merlins would have fared if operated as they were operated. The Merlin has about the same temperament as an Allison and also needs to be operated correctly for best engine life. The two engines both need proper care and feeding and I wonder what they got in service once jets were out and supplanted pistons as the new front-line engine.

 

[michaelmaltby]

"... Radar-equipped F-82s were used extensively by the Air Defense Command as replacements for the Northrop P-61 Black Widow night fighter. During the Korean War, Japan-based F-82s were among the first USAF aircraft to operate over Korea. "

I presume that the F-82's were flown by former P-61 Black Widow pilots .... any difference between radial and inline operations account for the poor Alison performance ....? We know they're tough engines because the Soviets used them hard ...

MM

 

[Milosh]

Custom built engines are not the same as mass production engines Greg.

 

[tyrodtom]

This is a good question and I am sure a lot of the answers stated here played a part. Immediately after the war the military was in disorder and the future was questionable. What direction was defense going? The US was the sole owner of the a-bomb and the Soviet Union was not an enemy. Jet aircraft seemed to be the way. As such decision rationale was probably all over the map including political and financial issues.
Here's a performance chart of US aircraft available to support ground troop immediately after the war.

Per the thread, I've chosen to compare the P-47N, P-51D, and have thrown in the following, P-82E, B-26C (A-26), F4U-4, F7F-3, and the A-1. I did not include the P-51H since it is stressed to lighter levels and thus would not be the best selection for air-to-ground work.

Empty Weight (k lbs)
B-26 22.6k
F7F-3 16.k
P-82E 14
P-47N 11
A-1 10.5
F4U 9.2
P-51D 7.1
Max TO weight
B-26 37.7
F7F 25.8
P-82 24
P-47 20
A-1 18
F4U 14.6
P-51 11.6
Load Carrying Capacity (max TO weight – empty weight)
B-26 15.1*
P-82E 10*
F7F 9.8*
P-47 9
A-1 7.5
F4U 5.4
P-51 4.5
*- Two engine aircraft will require more fuel and thus impact actual weapon carrying capacity. Also, V engines in the P-51 and P-82 would be more efficient than the radial jobs.
Sea level speed (mph)
P-51 383
F4U 374
F7F 367
P-47 364
B-26 361
A-1 348
P-82 unk
Max speed
P-47 467
P-82 465
F4U 453
P-51 442
F7F 435
B-26 372
A-1 366
Max range (miles)
B-26 3270 1800 w/4k bomb
P-82 2500 normal, 2700 ferry
P-51 2300
P-47 2200
A-1 1900 w/2k bombs
F7F 1573
F4U 1560

Looking at the stats it is easy to see why the B-26 with its load carrying capacity and range played the air-to-ground game up into the Vietnam war. The P-47N looks pretty good in the single engine category being the best lifter of the lot, and having the rugged reputation that it has. It could drop nearly twice the ordnance per sortie the P-51 which could significantly reduce sortie rates. It even lifts more and flies further than the F4U. And, it will out lift the A-1 and fly similar range. I think the P-47N would have made an excellent ground attack plane, much better than the P-51.

I don't know what model A-1 your figures are for, but the max t.o. weight of the A1E was very close to 25,000 lbs., not the 18,000 you have. That would have been it's normal, peacetime training mission weight. I've seen A1E's with 8000lbs just of ordance under wings with my own eyes, because I was one of the guys that hauled it to the line and installed it many times.

 

[gjs238]

Per the thread, I've chosen to compare the P-47N, P-51D, and have thrown in the following, P-82E, B-26C (A-26), F4U-4, F7F-3, and the A-1. I did not include the P-51H since it is stressed to lighter levels and thus would not be the best selection for air-to-ground work.

Where there enough P-47N's and F4U-4's manufacturered to support this?

 

[Milosh]

Where there enough P-47N's and F4U-4's manufacturered to support this?

A total of 1667 P-47Ns was produced by the Farmingdale plant between December 1944 and December 1945, when the Thunderbolt line finally closed down. 149 more P-47Ns were built by the Evansville factory.

Baugher

 

[tomo pauk]

F4U-4: 2050 pcs, F4U-4B: 297 pcs. Plus, almost 900 of post war versions (F4U-5, AU-1, F5U-7, night fighters...), many for export, though.
From 'US Hundred thousands' book.

 

[GregP]

Our engines aren't custom engines; they are stock Allisons overhauled and assembled to factory specs.

The only modern aftermarket items we use are things like O-rings, a few modern bearings for ones no longer available, and plastigage for fitting the cranks.

 

[davparlr]

I don't know what model A-1 your figures are for, but the max t.o. weight of the A1E was very close to 25,000 lbs., not the 18,000 you have. That would have been it's normal, peacetime training mission weight. I've seen A1E's with 8000lbs just of ordance under wings with my own eyes, because I was one of the guys that hauled it to the line and installed it many times.

I made an designation error, my comparison was not the A-1 but the AD-1 the first and only "A-1" available "immediately after the war", which is what I was comparing. The AD-5 (later A1E) did not fly until late 1951, benefiting from a lot of development that the 1945 P-47N never had (XP-72 with "N" wings?). I picked this point because that was when a lot of decision making was occurring as to where national defense was going. I got my data from Wagner's "American Combat Planes".

 

[davparlr]

Where there enough P-47N's and F4U-4's manufacturered to support this?

A previous post said 1800 were built. That seems like a goodly amount.

 

[dobbie]

So far as "air to mud" aircraft that the USAF had in their inventory, I think the P-47 would have been a more survivable aircraft than the mustang. Radials might need more maintenence than a liquid cooled engine, but radials can take more abuse and gunfire than any liquid cooled engine. Suggesting the Skyraider or the Corsair, while I think good suggestions indeed, would have meant ramping up for training, maintenence and flight operations. There wasnt much time for that. It is my belief that if the 47 had been fielded as a CAS fighter, there would have been a few more pilots coming back from operations

 

[MikeGazdik]

Actually I think it was brought up here once before that the P-51 Mustang had a better (less) loss rate in Air-to-mud missions than the P-47 Thunderbolt in Europe. Very surprising.

A question I have. What was the radius of the combat missions that were flown in Korea by the CAS units? I am going to surmise that they are not near the length of the missions over Germany late in the war.

 

[drgondog]

Longest radius was from Tokyo/Johnson AFB when 35th FBW was there, closest was Seoul. So, it depends

 

[Piper106]

Actually I think it was brought up here once before that the P-51 Mustang had a better (less) loss rate in Air-to-mud missions than the P-47 Thunderbolt in Europe. Very surprising.

I would take those numbers with a 'grain of salt'. I would think that the P-51 was working 'air-to-mud' later in the war than the P-47, and not facing the same caliber of German air defenses. My guess is that German flak units were not immune to the loss of effectiveness occuring among all the other German forces in the last months before VE day.

 

[drgondog]

I would take those numbers with a 'grain of salt'. I would think that the P-51 was working 'air-to-mud' later in the war than the P-47, and not facing the same caliber of German air defenses. My guess is that German flak units were not immune to the loss of effectiveness occuring among all the other German forces in the last months before VE day.

The P-47, specifically the 78th FG, scored the first German aircraft aircraft credited as destroyed on the ground by the 8th (or 9th AF) in February 1944. Thereafter the P-51 Mustang destroyed 3200 to 740 (P-47) for 8th AF in ETO while losing 569 to 200 (P-47). The Mustang faced every type airfield and rail flak defenses in the ETO - and far more frequently - particularly in Germany.