# Allied Gold-Match



## Soren (Apr 16, 2005)

*Vought F4U-4 Corsair *
Engine: Pratt Whitney R-2800-18.
Power: 2,450 hp.
Max speed: 446 mph.
Max Range: 1190 miles.
Empty Weight: 4,175 kg.
Max Weight: 6,654 kg.
Service ceiling: 12,649 m.
Wing Span: 12.5 m. 
Wing Area: 29.17 m2. 
Armament: Six .50 cal machine guns.





*Spitfire Mk.XIV.e*
Engine: Rolls-Royce Griffon 65. 
Power: 2,035 hp. 
Max Speed: 448 mph. 
Max Range: 457 miles. 
Empty Weight: 2,994kg. 
Max.Weight: 3,856kg. 
Service ceiling: 13,560 m. 
Wing Span: 11.23 m. 
Wing Area: 22.48 m2. 
Armament: two 20mm Hispano cannons and two .50 cal machine guns.

----------------------------------------------------------------------------------

If pilot skill is equal, then wich fighter would you bet your money on in a fight between the two ?


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## FLYBOYJ (Apr 16, 2005)

THE CORSAIR - Glycol's a drag!


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## DAVIDICUS (Apr 16, 2005)

There's an earlier "Gold Match" thread that pitted an F4U-4 against a P-47N. I recall that we concluded that the F4U-4 had the advantage below 30K feet.

I say the F4U-4 on this match.


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## Soren (Apr 16, 2005)

Guy's please explain your choices.


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## FLYBOYJ (Apr 16, 2005)

Robust F4U-4, big round engine with a lot of power, good hitting power (despite the spits cannons) as DAVIDICUS said, I would keep it below 30K


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## Soren (Apr 16, 2005)

One very superior feature about the Corsair, is that it has over double the range of the Spit on internal fuel.


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## DAVIDICUS (Apr 16, 2005)

FLYBOYJ said, "_as DAVIDICUS said, I would keep it below 30K_"

I don't think it would be necessary to keep it below 30K against the Spitfire. The P-47N though has the advantage of a very good turbosupercharger that enables it to maintain power at high altitudes.


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## Soren (Apr 16, 2005)

DAVIDICUS said:


> FLYBOYJ said, "_as DAVIDICUS said, I would keep it below 30K_"
> 
> I don't think it would be necessary to keep it below 30K against the Spitfire. The P-47N though has the advantage of a very good turbosupercharger that enables it to maintain power at high altitudes.



I would say DONT get below 3,000m or over 7,500m with the Spit XIV ! 

The Corsair has the roll-rate advantage through the whole speed and height band, but in a T&B fight with the Spit XIV the Corsair would be in deep deep trouble !

The Climb rate is about equal for the two aircraft, but armament definitely goes to the Spit XIV !

The number one evasive maneuver for the Corsair if a Spit XIV is on its tail, would have to be a quick 180* roll and a pull into a steep dive. While the number one evasive maneuver for the Spit XIV with a Corsair on its tail, would be a hard banking maneuver to either direction, or a tight loop.


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## Soren (Apr 16, 2005)

Pictures of the two aircraft:


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## FLYBOYJ (Apr 16, 2005)

If I'm in the Corsair and the spit is behind - snap roll to a split s, dive, pick up airspeed, then up, I would try to fight him in the vertical. I think although the climb rate is about the same, he may be able to accelerate faster. I know the Corsair could slow down faster, I would try to use that to my advantage, but definitely, I WONT TRY TO TURN WITH THE SPIT!


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## DAVIDICUS (Apr 16, 2005)

Soren said, "_but armament definitely goes to the Spit XIV !_ "

Why are two 20mm's and two .50's better than six .50's?

I don't agree. The armaments of each aircraft are roughly equal but the ability of each aircraft to sustain damage and continue the fight is not. Additionally, the F4U-4 has the capacity maintain fire for a longer period of time due to large ammunition stores.

The advantage here goes to the F4U-4.


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## Soren (Apr 16, 2005)

DAVIDICUS said:


> True, the armaments of each aircraft are roughly equal but the ability of each aircraft to sustain damage and continue the fight is not. Additionally, the F4U-4 has the capacity maintain fire for a longer period of time due to large ammunition stores.
> 
> The advantage here goes to the F4U-4.




However what good is this if the Corsair can't at all get into position behind the Spit ? As far as I see it, the Corsair has very little chance of getting on the Spit XIV's tail.

The Corsair might have a much better survivability, but against 2x 20mm Hispano's, it just wont last ! Four hits from those Hispano's and the Corsair is either going down or is effectively crippled to an extend where it can't fight nomore.


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## DAVIDICUS (Apr 16, 2005)

I edited my post after you responded. I thought you said that the armaments were equal.


The F4U-4 has advantages it can draw on in a dogfight as well. At any rate, four .50 hits could cripple the Spitfire as well. And remember that there are six .50's firing at the same time so the probability of landing lethal hits is increased. That liquid cooled, marvel of engineering it has for a powerplant couldn't take very much damage.


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## Soren (Apr 16, 2005)

> Why are two 20mm's and two .50's better than six .50's?



It takes alot more .50 cal rounds to take down a fighter than 20mm Hispano rounds !

A single Hispano round has more than 4 times the destructive power of a .50 cal round, thus 2xHispano's + 2x.50's is a much more lethal armament than 6x.50's.



> At any rate, four .50 hits could cripple the Spitfire as well



No way !! Do you have any idea how small an amount damage they will make ? The surface damage of a .50 cal is minimal at best !

The .50's have a small chance of doing any heavy damage, as they will have to hit key spots to do so.

The Spit will take many .50 cal hits before it is crippled ! Spitfire's have even flown home with 3x 20mm holes in them !

The Corsair can take more hits, no doubt, but it simply hasnt got the protection to face 2x Hispano's !


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## FLYBOYJ (Apr 16, 2005)

The only way I see getting behind the Spit is to sucker him to overshoot in the vertical or getting him to try to dive away, you would have to work on a quick firing solution before he starts turning.

In the Spit, I think if you could sucker the Corsiar to remain in the horizontal and keep him from diving, you'll probably be able to nail him, especially if you force the Corsair to turn.


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## Nonskimmer (Apr 16, 2005)

I'm so torn! I love _both_ aircraft! 
I wish they'd stop fighting! Please make them stop!


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## DAVIDICUS (Apr 16, 2005)

Soren said, "_A single Hispano round has more than 4 times the destructive power of a .50 cal round, thus 2xHispano's + 2x.50's is a much more lethal armament than 6x.50's_."

The US Air force conducted tests late in the war and concluded that a single 20mm had the effectiveness of two .50's. The US Navy also conducted tests and concluded that a single 20mm had the effectivenss of 2.5 .50's.

"_No way !! Do you have any idea how small an amount damage they will make ? The surface damage of a .50 cal is minimal at best ! The .50's have a small chance of doing any heavy damage, as they will have to hit key spots to do so. _"

Soren, who said anything about surface damage? The .50 could easily penetrate into and damage critical areas. And yes, I was talking about .50 strikes in "key" spots such as the engine which I specifically referenced. Six .50's firing at a rate of 850 rpm means 85 rounds per second that are set to converge within a three foot circle at 300 yards. 

I think we can just agree to disagree on this one.


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## Soren (Apr 16, 2005)

> The US Air force conducted tests late in the war and concluded that a single 20mm had the effectiveness of two .50's. The US Navy also conducted tests and concluded that a single 20mm had the effectivenss of 2.5 .50's.



Read this: http://www.quarry.nildram.co.uk/WW2guneffect.htm

The 20mm Hispano Mk.II was over 4 times as powerful pr round, and the gun itself 3.3 times as powerful as the M2 Browning.

Also a single 20mm round in one of the Corsair's fuel tanks, and "CABOOM !!".....the Corsair is finished. While a .50 cal round won't explode a fuel tank at all, highest having it rupture after multiple hits.

Also the destructiveness of the 20mm Hispano round decreases much more slowly than the .50 cal round, making it better at longer ranges.



> Soren, who said anything about surface damage?



Surface damage is one of the most destructive types of damage an a/c can recieve. 



> The .50 could easily penetrate into and penetrate critical areas. And yes, I was talking about .50 strikes in "key" spots such as the engine which I specifically referenced.



But what are the chances the .50's are going to penetrate the Engine block ? I can tell you that they are slim to none ! The .50's simply don't have the penetrating power to penetrate the engine block at the angles obtained in a dogfight. And the chance of hitting anything vital other than the engine is also very small with the relatively low RoF pr gun.

If the Browning M2 had a better RoF it would have been better, as then it could deliver a more lethal dose of surface damage at the time, but fact is it didnt. (Wich is why the Brits rejected the M2 so many times)



> Six .50's firing at a rate of 850 rpm means 85 rounds per second that are set to converge within a three foot circle at 300 yards.



That circle is going to be alot bigger when the plane is flying because of all the vibrations caused by the engine and propeller.


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## Soren (Apr 16, 2005)

> The F4U-4 has advantages it can draw on in a dogfight as well.



Yes its roll-rate and its ability to dive like a rock, and thats it. If the Corsair even 'once' tries to T&B fight, it is dead meat !

While the initial climb of the two aircraft is about the same, the Spit XIV will climb away after short time, and is also slightly faster in straight flight, thus the Spit dominates the fight.

Also there are two versions of Spit Mk.XIV, the original wing version and the Clipped Wing version. Against the CW version, the Corsair has only a very slim advantage in roll rate, and is still far outclassed in a T&B fight.

With equal pilots, it is far more likely that its the Spit XIV thats going to be on the Corsair's tail than vice versa.


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## DAVIDICUS (Apr 16, 2005)

That is an interesting article Soren. I wish I had the USAAF and USN studies that state differently. All I know is their conclusions. Perhaps their tests were based on field testing and not solely on mathematical calculations as the site you have offered.

The Mk XIVe was a lightly constructed aircraft. If your arguments are valid, then P-51's would have had great difficulty in taking out ME-109's and even greater difficulty in taking out FW-190's which had radial engines. I don't believe this was the case.

I just don't see why a Mk. XIVe would have been any more difficult to bring down than an Me-109. 

As to the ability of the .50 to damage an engine, consider the following:

The RAF conducted studies of the ability of the .50 to penetrate hardened armor plate. (As opposed to damaging an engine)

At 200 yards

O degrees, 20mm of penetration
20 degrees, 14mm of penetration
40 degrees, 8mm of penetration

As you can see, a .50 can quite easily inflict fatal damage to an engine.


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## FLYBOYJ (Apr 16, 2005)

I think talking about taking hits and how much damage each aircraft is going to absorb is rubbish. I believe if either aircraft during this "hypethetcial" dogfight places themseft in a position where the're taking on hits is doomed - end of story. Sure we could arge how much more powerful a 20mm round is over a .50 cal, and how much or little each aircraft could absorb, but bottom line, the minute you're getting hit, its time to put the throttle to the wall, go to high prop pitch and RUN LIKE HELL!  

Now Soren, NO FAIR - you keep that clipped wing thing out of this! If not I'm gonna get my Goodyear F2G and put 20mms on it


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## Nonskimmer (Apr 16, 2005)

What about the Brit clipped winged Corsairs? 
Alright, it was done to fit the damn things into the RN carrier hangar decks, but what the hell.


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## Soren (Apr 16, 2005)

DAVIDICUS said:


> That is an interesting article Soren. I wish I had the USAAF and USN studies that state differently. All I know is their conclusions. Perhaps their tests were based on field testing and not solely on mathematical calculations as the site you have offered.



David I know about the tests, and these tests also revealed that a single 20mm Hispano round would explode a self-sealing fuel tank, while the .50 cal would only rupture it to an extend where it couldnt self-seal.

There are no miracles in ballistics, it can all be explained by math and physics.


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## DAVIDICUS (Apr 16, 2005)

I think you are referring to a test that RG_Lunatic mentioned where a 20mm would blow the bottom of the tank off at the seam where the .50 would leave a 4" x 8" exit hole. (not exactly just "an extent where it couldn't self seal") I do not believe that that was part of the U.S. tests I am referring to.

Of course, I don't know what the U.S. tests were based on. I assume they involved field tests as any such valid tests should. Field tests are very valuable and often discredit conclusions based on calculations. If you miss a variable or incorrectly assign a greater or lesser weight to a variable, field tests will pick it up. I would be interested in learning how the site you referred me to came to a different conclusion from the American tests. Something obviously doesn't add up. 

I think FLYBOYJ hit the nail on the head here. Either aircraft carries ample weaponry to blast the other from the sky.

Oh, before I forget, you mentioned the clipped wing version of the Mk XIV. There were two versions of the F4U-4 too. The other had four 20mm cannons.


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## Soren (Apr 16, 2005)

FLYBOYJ said:


> I think talking about taking hits and how much damage each aircraft is going to absorb is rubbish. I believe if either aircraft during this "hypethetcial" dogfight places themseft in a position where the're taking on hits is doomed - end of story. Sure we could arge how much more powerful a 20mm round is over a .50 cal, and how much or little each aircraft could absorb, but bottom line, the minute you're getting hit, its time to put the throttle to the wall, go to high prop pitch and RUN LIKE HELL!



And I think your right about that assessment, however a good armament is also a big advantage, as depending on how good it is, it will take less time to take down that enemy infront of you.



> Now Soren, NO FAIR - you keep that clipped wing thing out of this! If not I'm gonna get my Goodyear F2G and put 20mms on it



All is fair in love and war, eye ?


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## Soren (Apr 16, 2005)

DAVIDICUS said:


> . I would be interested in learning how the site you referred me to came to a different conclusion from the American tests. Something obviously doesn't add up.



What doesnt add up ? It is obvius that a "Cannon" is more powerful than a HMG isnt it ?



> I think FLYBOYJ hit the nail on the head here. Either aircraft carries ample weaponry to blast the other from the sky.



I quite agree with this, "BUT", the more quickly your can get the enemy down the better.



> Oh, before I forget, you mentioned the clipped wing version of the Mk XIV. There were two versions of the F4U-4 too. The other had four 20mm cannons.



The F4U-4C with the 4x20mm cannons only numbered 297 in WW2 

Btw, there were three versions of the F4U-4.


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## DAVIDICUS (Apr 17, 2005)

_"What doesnt add up ?"_

That site's conclusions vs. the USAAF and USN's conclusions. You asserted that the MkXIVe had a superior armament and I claimed that it was roughly equal to the F4U-4. You and I were relying on conclusions from different sources remember?


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## Soren (Apr 17, 2005)

DAVIDICUS said:


> _"What doesnt add up ?"_
> 
> That site's conclusions vs. the USAAF and USN's conclusions. You asserted that the MkXIVe had a superior armament and I claimed that it was roughly equal to the F4U-4. You and I were relying on conclusions from different sources remember?



That sites conclusions are probably the most accurate conclusions made on WW2 fighter armament. 

The 6x.50's were enough against fighters, but it was by no means as effective as the 2xHispano+ 2x.50's armament, wich is the point.


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## DAVIDICUS (Apr 17, 2005)

Soren, this is getting a little old.

Your assertion that, "The 6x.50's were enough against fighters, but it was by no means as effective as the 2xHispano+ 2x.50's armament, wich is the point." is simply not borne out by the concusions of the U.S. tests, hence the disagreement that errupted between us.

"By no means as effective?" Soren, we don't have the U.S. tests before us to examine but clearly, they reached a different conclusion. It is possible that their conclusions were reached through field tests. If so, then the conclusions reached in the site you offered are not valid. 

Even today, design engineers in the field of ballistics, both sporting and military, rely heavily on field testing to verify the terminal behavior of projectiles. If field testing always confirmed conclusions reached through pen and paper, it would be wasteful to conduct them. Obviously, field testing does not always confirm conclusions based on calculations of known relevant variables.

I have never claimed that a .50 is as powerfull or effective as a 20mm. I have, however, claimed, per my understanding of the U.S. tests, that two .50's were roughly equivalent to a 20mm. Therefore, if a plane has four .50's in place of two 20mm's, the substitution is of rough equivalence. 

Additionally, compared to the Corsair, the Spitfire had a glass jaw and yes, four .50 cal. hits to it's powerplant could very well inflict fatal damage. (I established this through the recital of RAF tests of the .50's ability to penetrate hardened armor plate.) Lastly, I know you are well aware that the P-51 was vulnerable to 8x57mm hits to its engine. The implications are rather obvious.


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## Soren (Apr 17, 2005)

DAVIDICUS said:


> Additionally, compared to the Corsair, the Spitfire had a glass jaw and yes, four .50 cal. hits to it's powerplant could very well inflict fatal damage. (I established this through the recital of RAF tests of the .50's ability to penetrate hardened armor plate.) Lastly, I know you are well aware that the P-51 was vulnerable to 8x57mm hits to its engine. The implication are rather obvious.



David the angles of ballistic hits accuring in dogfights are often over 40-60 degrees from vertical, where the 8x57mm and .50 cal will not penetrate the engine block. 

However if four .50's hit the engine block at 0-30 degrees from vertical, the engine is out. But by comparison a single 20mm hit on the Corsairs engine, and its blown out of the sky ! The same will happen if one of its internal fuel tanks are hit by 20mm Hispano round.

This is why 2xHispano's are more effective than 4x.50's.


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## Anonymous (Apr 18, 2005)

Soren said:


> > The US Air force conducted tests late in the war and concluded that a single 20mm had the effectiveness of two .50's. The US Navy also conducted tests and concluded that a single 20mm had the effectivenss of 2.5 .50's.
> 
> 
> 
> ...



Ummm, the Corsair has only one fuel tank. It is located in front of the pilots feet. It is protected by the engine in the front, and by armor plate from behind and from low and behind, and it is fully self-sealing. The F4U-4 was considered "protected" from .50 fire from the front AND 20MM FIRE FROM THE REAR! So the Corsair only has one primary area of vulnerability which lies between the back of the cockpit and extends to the engine, and this is well protected by armor.

Now lets consider the Spitfire. First, it has two non-self-sealing fuel tanks in the wings, plus one self-sealing fuel tank in the fuselage in front of the pilot. The fuselage tank is somewhat protected, but there is no where near the amout of armor protection of the Corsair, and British self-sealing tanks weren't quite as good as US self-sealing tanks. Any .50 API hit to the fuel tanks and the likely result... KABOOM! Additionally, any hit to the Griffon inline engine or its cooling system, which extends from the engine back along the front of the fuselage and into the wings and their radiators, and the Spitfire is finished. The R2800 engine on the Corsair is no where near as vulnerable, and there is no glycol or radiators to cool the engine.



Soren said:


> Also the destructiveness of the 20mm Hispano round decreases much more slowly than the .50 cal round, making it better at longer ranges.



This is only partially true. The .50 holds its ke/momentum better than the Hispano. However, Hispano 20mm HE rounds will maintain most of their destructive power at any range, so reasonably speaking, they are about 2.5x as potent by ke/momentum damage at close range but only about 1.5x as potent at long range (500m) for API rounds. But for HE rounds they are perhaps 4x as potent at any range. On the other hand, the Hs.II fires at only 600 rpm, the .50 fires at 800 rpm, making up a third of the difference in hitting power, and also HE rounds suffered dud rates of 25% or more, which must also be factored in.



Soren said:


> > Soren, who said anything about surface damage?
> 
> 
> 
> Surface damage is one of the most destructive types of damage an a/c can recieve.



And given the higher number of expected .50 hits you would expect at least as much surface damage. The .50's made pretty good size exit holes, and most enemy aircraft (including the Spit XIV) had thinner sheetmetal and less internal structure and were more subject to surface damage.

Also, the fabric part of the Corsair wing is almost impervious to holeing damage and HE rounds will go right through w/o detonating. If it misses structure it is likely to exit the wing, even if it hits the sheeting on the other side (most HE rounds had some delay in the fusing), without doing much damage at all.



Soren said:


> > The .50 could easily penetrate into and penetrate critical areas. And yes, I was talking about .50 strikes in "key" spots such as the engine which I specifically referenced.
> 
> 
> 
> But what are the chances the .50's are going to penetrate the Engine block ? I can tell you that they are slim to none ! The .50's simply don't have the penetrating power to penetrate the engine block at the angles obtained in a dogfight. And the chance of hitting anything vital other than the engine is also very small with the relatively low RoF pr gun.



What? Soren, the .50 API round could penetrate a engine block at least to the crank case from 500 meters. You should take a large ball peen hammer or small sledge to the side of an engine some time... they ain't that strong. The block around the water jacket is only a few millimeters thick and that is cast iron not steel. The whole thing is designed to be as light as possible and to provide as much rigidity to support the crankshaft and the cyilinder bores. We used to shoot up an old truck's engine (sitting on the dirt) with our M1 Garand's, even it could penetrate the block easily using ordinary ball ammo. Besides that, the blowers and carberators are mostly aluminim and magnesium, and the whole engine compartment is packed with vulnerable things like (on the Spit) water hoses, fuel lines, and electrical systems. A .50 hit to a liquid cooled engine was almost certainly a deathblow.

The Spitfire XIV was no where near as tough as the F4U-4 Corsair, which is generally accepted as the toughest fighter of WWII.



Soren said:


> If the Browning M2 had a better RoF it would have been better, as then it could deliver a more lethal dose of surface damage at the time, but fact is it didnt. (Wich is why the Brits rejected the M2 so many times)
> 
> 
> 
> ...



But the beaten area of the Hispano II in the wing of a Spitfire was huge compared to that of the .50 BMG! The Hispano has about 3 times the recoil and it relies on the wing itself for its structure. The Spitfire wing was really too weak to support the Hispano, it was known to twist when firing.

For this reason, the Hispano maximum range even with the Gyro gunsights was generally considered to be not more than about 300 yards, where with the .50's on the P-47, a very solid gun platform with very rigid wings, pilots were scoring at as much as 800 yards.

Also the .50's could easily fire at a higher rate. A new gun was set to either approximately 750 rpm for the P-47, or 800 rpm for all others. However, once a gun got worn in by firing off a few belts of ammo, its RoF would rise and this could amount to 50+ more rpm on a well worn in gun. Amorer's also had tricks to speed up the gun, and RoF's as high as 950-100 rpm per gun were common on P-51B's and D's setup with only 4 guns.

The USA considered that 800 rpm was sufficient. Late in the war they decided to improve that to 1200 rpm with the M3, but that could have been done earlier, there was no magic involved.

=S=

Lunatic


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## Anonymous (Apr 18, 2005)

Soren said:


> While the initial climb of the two aircraft is about the same, the Spit XIV will climb away after short time, and is also slightly faster in straight flight, thus the Spit dominates the fight.



Climb rates are almost identical to 25,000 feet, the Spit XIV might have a slight edge but not much. As for level speeds, the F4U-4 was capable of 464 mph! Even with the capped pylons installed, it was a 453 mph plane and it was faster at lower altitudes than the Spitfire.[/quote]


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## Anonymous (Apr 18, 2005)

FLYBOYJ said:


> I think talking about taking hits and how much damage each aircraft is going to absorb is rubbish. I believe if either aircraft during this "hypethetcial" dogfight places themseft in a position where the're taking on hits is doomed - end of story. Sure we could arge how much more powerful a 20mm round is over a .50 cal, and how much or little each aircraft could absorb, but bottom line, the minute you're getting hit, its time to put the throttle to the wall, go to high prop pitch and RUN LIKE HELL!
> 
> Now Soren, NO FAIR - you keep that clipped wing thing out of this! If not I'm gonna get my Goodyear F2G and put 20mms on it



The point is the F4U-4 is more likely to survive a few hits with little or no damage. The Spitfire is much more vulnerable.

As for the clipped wing Spit, it would not have turned so well, it traded turn rate for RoR, and this got pretty severe above mid altitudes.

While I agree the Spitfire could probably "turn-and-burn" better than the Corsair, I think they are more evenly matched in this regaurd than Soren does. And at high speeds, they would be virtually even.

In general, I'd say the Spit XIV probably wins the fight above 30K, the F4U-4 probably wins below 22K, and inbetween it's very even.


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## Anonymous (Apr 18, 2005)

Soren said:


> DAVIDICUS said:
> 
> 
> > Additionally, compared to the Corsair, the Spitfire had a glass jaw and yes, four .50 cal. hits to it's powerplant could very well inflict fatal damage. (I established this through the recital of RAF tests of the .50's ability to penetrate hardened armor plate.) Lastly, I know you are well aware that the P-51 was vulnerable to 8x57mm hits to its engine. The implication are rather obvious.
> ...



The .50 AP(I) would pentrate the block at extremely shallow angles. But besides that, almost any angle of fire against the engine presents more area of steep angles than shallow ones. If you are shooting from the rear of the plane, you are most likely to hit the rear of the engine (after penetrating the fuselage and maybe the cockpit). Occasionally a hit would be at a shallow angle, but it would be much less common than a steep angle hit. Even a shallow angle hit would quite likely breech the water jacket.



Soren said:


> However if four .50's hit the engine block at 0-30 degrees from vertical, the engine is out. But by comparison a single 20mm hit on the Corsairs engine, and its blown out of the sky ! The same will happen if one of its internal fuel tanks are hit by 20mm Hispano round.



What? R2800's were known to take tremendous damage and continue to run for hundreds of miles. Whole cylinders could be blown off and the plane would keep on flying. And again, the Corsair only has the one fuel tank, and comparatively, it is very well protected. It is very unlikely a 20mm HE round would reach the fuel tank, it would take a shot almost strait up from the bottom or at 90 degrees off to either side.



Soren said:


> This is why 2xHispano's are more effective than 4x.50's.



Soren, you are ignioring the RoF, and you are attributing HE damage to the 20mm while discounting incendiary effect for the .50's. 4 x .50's will put out 3200 rpm, vs. 2 x Hs.II's putting out 1200 rpm. That is a difference of 2.67:1 in favor of the .50's, and basically cancels out the 20mm advantage even by your own sources.

You are also leaving out the range advantage of the .50's. In the Spitfire, the range of the Hs.II was limited by the quality of the Spit as a platform for that gun, which was relatively poor. On the otherhand, the Corsair was a very good gunplatform period. Spit wings were known to flex, Corsair wings did not.

You are also leaving out the trigger time issue, the Spit XIV 20mm last 12 seconds, vs the .50's on the F4U-4 which gives 30 seconds of trigger time. This allows the Corsair pilot the freedom to take longer shots and lower probability shots.


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## Soren (Apr 18, 2005)

RG the Hispano MK.II had RPS of 10, while the Browning M2 .50 cal had an RPS of 13= 

Hispano Mk.II: 600 rpm 

M2 .50 cal: 780 rpm

Not such a big difference now is it ?  

Also don't forget that the Spit XIV carried 2xHispano's "PLUS" 2x.50's !



> While I agree the Spitfire could probably "turn-and-burn" better than the Corsair, I think they are more evenly matched in this regaurd than Soren does. And at high speeds, they would be virtually even.



Probably ??!!!  

RG look at the wing and power loadings for the two aircraft, and it should be pretty obvious that the Spit XIV is a MUCH better T&B fighter !



> As for the clipped wing Spit, it would not have turned so well, it traded turn rate for RoR, and this got pretty severe above mid altitudes.



Source ??!! 

The wings were clipped to *improve* low altitude maneuverability !!

Anyway the Spit XIV CW would still easely outturn the Corsair, and now also roll with it !



> In general, I'd say the Spit XIV probably wins the fight above 30K, the F4U-4 probably wins below 22K, and inbetween it's very even.



Below 3,000m or above 7,500m and the Corsair is in BIG trouble against a Spit XIV.e !



> As for level speeds, the F4U-4 was capable of 464 mph!



I think you missed something ! :

*F4U-4 Max speed: 446 mph*


----------



## Soren (Apr 18, 2005)

As for Cannon and MG's: 
_*while a machine gun bullet relying in kinetic energy has to hit something vital to have an effect (or score so many hits close together that it shreds the structure) - it otherwise just makes small holes - a single cannon strike anywhere on the aircraft can inflict significant damage. It is also argued that a hit by one large cannon shell is more effective than hits by several smaller shells generating the same total damage score, as these will be spread across the aircraft instead of being concentrated at one point*._


----------



## Soren (Apr 18, 2005)

> Any .50 API hit to the fuel tanks and the likely result... KABOOM!



No, they will only rupture it, never make it explode.



> and British self-sealing tanks weren't quite as good as US self-sealing tanks.



RG for Christs sake could you cut that pro-U.S. attitude for just ONCE maybe !?

Why are U.S. selfsealing fuel tanks better than British ones ? and what is your source on this ?


----------



## Soren (Apr 18, 2005)

> What? Soren, the .50 API round could penetrate a engine block at least to the crank case from 500 meters.



Yeah at a 90 degree angle !  AS soon as we move onto 40 degree's from vertical or more, its unlikely that its going to penetrate. Also going through the first layer of sheet metal will slow down any incoming .50 cal round.



> What? R2800's were known to take tremendous damage and continue to run for hundreds of miles. Whole cylinders could be blown off and the plane would keep on flying.



A single 20mm Hispano hit and the engine is GONE !



> And again, the Corsair only has the one fuel tank, and comparatively, it is very well protected. It is very unlikely a 20mm HE round would reach the fuel tank, it would take a shot almost strait up from the bottom or at 90 degrees off to either side.



A single 20mm AP round to the fuel tank would blast the Corsair down from the sky, and a 20mm Hispano AP round could easely reach the Corsair's internal fuel tank !


----------



## the lancaster kicks ass (Apr 18, 2005)

wow that's quite a pic.........


----------



## Anonymous (Apr 18, 2005)

Soren said:


> RG the Hispano MK.II had RPS of 10, while the Browning M2 .50 cal had an RPS of 13=
> 
> Hispano Mk.II: 600 rpm
> 
> ...



No, but it is 4 x .50's vs. 2 x 20mm's that are being compared. So my numbers are valid, 3200 vs. 1200 = 2.66:1. That is a big difference.



Soren said:


> Also don't forget that the Spit XIV carried 2xHispano's "PLUS" 2x.50's !



Ahh... but they are not really very useable together. The trajectories differ. Most Spitfire pilots did not fire the cannon and mg's together.



Soren said:


> > While I agree the Spitfire could probably "turn-and-burn" better than the Corsair, I think they are more evenly matched in this regaurd than Soren does. And at high speeds, they would be virtually even.
> 
> 
> 
> ...



The Corsair could pull some moves the Spit could not, and it rolled better. It could certainly turn well enough to get a firing resolution on the Spitfire at the start of any turn.



Soren said:


> > As for the clipped wing Spit, it would not have turned so well, it traded turn rate for RoR, and this got pretty severe above mid altitudes.
> 
> 
> 
> ...



Not according to Boscomb Down (Report No. A.&A.E.E./Res/179 - Mar. 23, 1943):








Soren said:


> Anyway the Spit XIV CW would still easely outturn the Corsair, and now also roll with it !



It seems not. The Corsair also could drop flaps to increase lift and improve turn rates. This was often done against Zero's when in an advantagous numerical situation to finish them off more quickly - the F4U could turn inside even the Zero to gain a shot! The Corsair flaps could be lowered at any speed, if the plane was going too fast, they simply would not deploy until the plane slowed down enough.



Soren said:


> > In general, I'd say the Spit XIV probably wins the fight above 30K, the F4U-4 probably wins below 22K, and inbetween it's very even.
> 
> 
> 
> Below 3,000m or above 7,500m and the Corsair is in BIG trouble against a Spit XIV.e !



Below about 8000 feet the Spitfire has a tiny speed advantage, from 8000 to about 26000 feet the F4U-4 is definitely faster, and in the 10000-22000 foot range this is quite substantial.

Also, to achieve this kind of performance the Spit XIV had to use +25 lbs of boost, which was a 3 minute rating. The F4U-4 could sutstain this power level for a full 10 minutes (actually 11 minutes but the doc rounds this to 10).



Soren said:


> > As for level speeds, the F4U-4 was capable of 464 mph!
> 
> 
> 
> ...



Which is WRONG! Here's the relevant pages from the F4U-4 pilot handbook excerpts available at the USN site:






I've provided the conversions in blue. Also notice that the 4.9 minute climb to 20,000 feet includes capped pylons, so the climb would be a little faster with out them too.

=S=

Lunatic


----------



## Soren (Apr 18, 2005)

> No, but it is 4 x .50's vs. 2 x 20mm's that are being compared. So my numbers are valid, 3200 vs. 1200 = 2.66:1. That is a big difference.



Nope its not, and lets be a little realistic here shall we. 

Read this: 
*While a machine gun bullet relying in kinetic energy has to hit something vital to have an effect (or score so many hits close together that it shreds the structure) - it otherwise just makes small holes - a single cannon strike anywhere on the aircraft can inflict significant damage. It is also argued that a hit by one large cannon shell is more effective than hits by several smaller shells generating the same total damage score, as these will be spread across the aircraft instead of being concentrated at one point.*

Now look at the Hispano and .50 cal hit photo I presented. A single 20mm Hispano inflicts surface damage wich is far beyond that of even twenty .50 cal hits, wich btw will be spread. Now think about what an 20mm Hispano AP round will do ! 



> Ahh... but they are not really very useable together. The trajectories differ. Most Spitfire pilots did not fire the cannon and mg's together.



From 0-300y they differ very little, as they both have very straight ballistics at those ranges.




> The Corsair could pull some moves the Spit could not,



Wich ? It could roll and dive faster, and thats it.



> and it rolled better.



Noticably better than the full wing type, while only slightly better than the CW type.



> It could certainly turn well enough to get a firing resolution on the Spitfire at the start of any turn.



Most fighters could RG. The Fw-190 A series probably had he fastest 45 degree banking-turn of any WW2 fighter.



> Not according to Boscomb Down (Report No. A.&A.E.E./Res/179 - Mar. 23, 1943):



No according to most books about it.



> It seems not. The Corsair also could drop flaps to increase lift and improve turn rates.



RG the CW version didnt turn as tight as the full wing version for obvious reasons, but it still turned alot tighter than the Corsair ! Go ahead and look at the Spit XIV CW's Wing and power loading, and you will see that it is still a very much better T&B fighter ! 

Full wing version Wing Area: 242 sq ft (22.48 m2). 
CW version Wing Area: 231 sqft (21.46 m2).

The reduction in turning ability was minimal !

Also your arguement about the flaps is ridiculous, as every WW2 fighter had that ability !



> Below about 8000 feet the Spitfire has a tiny speed advantage, from 8000 to about 26000 feet the F4U-4 is definitely faster, and in the 10000-22000 foot range this is quite substantial.



RG it is at 26,000ft that the Spit XIV has its max speed, at wich it is 2 mph faster than the F4U-4, but 4 mph slower according to your data. (Hardly any difference)



> Also, to achieve this kind of performance the Spit XIV had to use +25 lbs of boost, which was a 3 minute rating. The F4U-4 could sutstain this power level for a full 10 minutes (actually 11 minutes but the doc rounds this to 10).



RG the F4U-4 could use its boost for only 5 min.



> Which is WRONG!



No its actually quite true.



> Here's the relevant pages from the F4U-4 pilot handbook excerpts available at the USN site:



RG your stats are for the post-war R-2800-42W engine with 2,500 hp, while mine is for an engine wich actually took part in WW2, the R-2000-18W engine with 2,350 hp.

_The F4U-4 was one of the more important variants of the Corsair. Seven prototypes were built, anticipating the many problems which would arise from the proposed changes. Five F4U-1s were pulled from the production line to be modified into the XF4U-4A, ‘4B, ‘4C, ‘4D and’4E. Two more "FG-1" aircraft (identical to the Vought F4U-1) were pulled from Goodyear’s production line. They were all fitted with the Pratt-Whitney R-2800-18W engine which produced 2,100 hp (1,567 kW) and sported a new four blade prop. The engine also had methanol-water injection which boosted the war emergency power rating to 2,350 hp (1,828 kW) *for about five minutes.* The 18W engine necessitated changes in the basic airframe to handle the extra power and the turbo air intake was mounted on the inside bottom of the engine cowling (it was called a "chin scoop") while air for the intercooler and oil cooler continued to be drawn from the wing slots. *The F4U-4 was clocked at a top speed of 446 mph at 26,200 ft.* _

Source: "Corsair: The F4U in World War II and Korea" by Barrett Tillman and Kenneth A. Walsh.



> Also notice that the 4.9 minute climb to 20,000 feet includes capped pylons, so the climb would be a little faster with out them too.



The Spit was still better in the climb, especially a prolonged one !


----------



## Anonymous (Apr 18, 2005)

Soren said:


> > The Corsair could pull some moves the Spit could not,
> 
> 
> 
> Wich ? It could roll and dive faster, and thats it.



It could also do negative G manuvers and a neg-G into a roll move that few other planes could match.



Soren said:


> > and it rolled better.
> 
> 
> 
> Noticably better than the full wing type, while only slightly better than the CW type.



As pointed out in the RAF study the CW wing was only of advantage to Spitfires with poorly functioning ailerons. Spitfire quality control was not good, planes differed wildly.



Soren said:


> > Not according to Boscomb Down (Report No. A.&A.E.E./Res/179 - Mar. 23, 1943):
> 
> 
> 
> No according to most books about it.



And those books are to be taken over the actual test reports? LOL!



Soren said:


> > It seems not. The Corsair also could drop flaps to increase lift and improve turn rates.
> 
> 
> 
> ...



Hmmm... lets do the math....

Spit XIV = 8500 lbs / 242 sf = 35.12 lbs/sf
F4U-4 = 12405 lbs / 314 sf = 39.5 lbs/sf

That's not that different. And the F4U-4 is carrying quite a bit more fuel than the Spit XIV, if we balance that out some the wingloading difference becomes much more equal. Removing the capped pylons alone knocks off 100 lbs. Yes the Spit has an advantage but it's not so substantial.



Soren said:


> Also your arguement about the flaps is ridiculous, as every WW2 fighter had that ability !



The Spitfire XIV had 3 flap positions - Up, Down, Full Down. There was no automatic mechanism - if the pilot tried to drop the flaps at too high a speed the hydrolic system would try to do so and the system or the flap could be damaged. The F4U-4 had an automatic flap system which could be deployed to any angle between full up and full down, though there were about 4 or 5 notch points on the selector. The pilot could set the flaps to go full down at any speed, and they would deploy in relation to the airspeed.

Both the Corsair and the P-51 were known to use combat flaps at high speeds. Very few other planes were able to do so.



Soren said:


> > Below about 8000 feet the Spitfire has a tiny speed advantage, from 8000 to about 26000 feet the F4U-4 is definitely faster, and in the 10000-22000 foot range this is quite substantial.
> 
> 
> 
> RG it is at 26,000ft that the Spit XIV has its max speed, at wich it is 2 mph faster than the F4U-4, but 4 mph slower according to your data. (Hardly any difference)



Which is why that altitude is chosen by the authors for the comparison? The best speed for the F4U-4 is found at about 21,500 feet.

What top speed are you using for the Spit XIV?



Soren said:


> > Also, to achieve this kind of performance the Spit XIV had to use +25 lbs of boost, which was a 3 minute rating. The F4U-4 could sutstain this power level for a full 10 minutes (actually 11 minutes but the doc rounds this to 10).
> 
> 
> 
> RG the F4U-4 could use its boost for only 5 min.



Look at the chart - it clearly shows 10 minutes WEP + 10 minutes MP.



Soren said:


> > Here's the relevant pages from the F4U-4 pilot handbook excerpts available at the USN site:
> 
> 
> 
> RG your stats are for the post-war R-2800-42W engine with 2,500 hp, while mine is for an engine wich actually took part in WW2, the R-2000-18W engine with 2,350 hp.



Wrong, the figures I've given are for the R2800-18W, clearly specified in the pilot handbook:







Soren said:


> _The F4U-4 was one of the more important variants of the Corsair. Seven prototypes were built, anticipating the many problems which would arise from the proposed changes. Five F4U-1s were pulled from the production line to be modified into the XF4U-4A, ‘4B, ‘4C, ‘4D and’4E. Two more "FG-1" aircraft (identical to the Vought F4U-1) were pulled from Goodyear’s production line. They were all fitted with the Pratt-Whitney R-2800-18W engine which produced 2,100 hp (1,567 kW) and sported a new four blade prop. The engine also had methanol-water injection which boosted the war emergency power rating to 2,350 hp (1,828 kW) *for about five minutes.* The 18W engine necessitated changes in the basic airframe to handle the extra power and the turbo air intake was mounted on the inside bottom of the engine cowling (it was called a "chin scoop") while air for the intercooler and oil cooler continued to be drawn from the wing slots. *The F4U-4 was clocked at a top speed of 446 mph at 26,200 ft.* _
> 
> Source: "Corsair: The F4U in World War II and Korea" by Barrett Tillman and Kenneth A. Walsh.



Which is clearly wrong in light of the declassified USN pilot handbook data that became available after that book was published in 1979.

=S=

Lunatic


----------



## Anonymous (Apr 18, 2005)

Soren said:


> > Any .50 API hit to the fuel tanks and the likely result... KABOOM!
> 
> 
> 
> No, they will only rupture it, never make it explode.



What? You mean to tell me you can put magnesium burning at 4000 degrees and a strong oxidizer into a fuel tank with gasoline and not have it go boom? Wow when did the laws of nature change?



Soren said:


> > and British self-sealing tanks weren't quite as good as US self-sealing tanks.
> 
> 
> 
> ...



US self-sealing tanks are always listed as having been "best in the world". British self-sealing tanks were a little better than the German tanks, but not a lot.

Why are they better? Well, mostly because more material was used to make it self sealing, at the cost of extra weight and some reduction in fuel capacity. But also because the self sealing rubber/plastic compounds were superior. German self sealing tanks were rather poor at altitude, the synthetic rubber stuff they used would freeze and become powdery.


----------



## Anonymous (Apr 19, 2005)

Soren said:


> > What? Soren, the .50 API round could penetrate a engine block at least to the crank case from 500 meters.
> 
> 
> 
> Yeah at a 90 degree angle !  AS soon as we move onto 40 degree's from vertical or more, its unlikely that its going to penetrate. Also going through the first layer of sheet metal will slow down any incoming .50 cal round.



That is just totally wrong. Why do you think they use the .50 sniper guns for anti-vehicle work? It's because any hit to the engine is very likely to destroy the engine. The typical water jacket along the outside of the pistons on a liquid cooled engine is only about 4-5 mm thick, and its made of soft cast iron. From 90 degrees the .50 AP(I) round would go through the water jacket, through the cylinder wall, through the cylinder wall on the opposite side, knock a valve lifter out of the valve bay, and then maybe pass through the valve bay side of the opposite cylinder jacket and into a cylinder on the opposite side of the engine. A .50 could reach the crankshaft from any angle as long as it did not get stopped by a rod or a camshaft.

Also, HE rounds were shown to do almost zero damage to steel plates as thin as a few mm unless the detonation occures while the round is impacting the plate. Any indirect hit by an HE type 20mm round against the side of an engine block is likely to result in a non-contact detonation and not breech the block at all!



Soren said:


> > What? R2800's were known to take tremendous damage and continue to run for hundreds of miles. Whole cylinders could be blown off and the plane would keep on flying.
> 
> 
> 
> A single 20mm Hispano hit and the engine is GONE !



Again wrong! P-47's, Corsairs, and Hellcats took 20mm hits to the front of the engine and survived frequently durring WWII. Cylinders can be blown completely off and asside from a little oil loss the engine can keep right on running. I think there was more than one case of R2800's flying home missing 3 cylinders.



> And again, the Corsair only has the one fuel tank, and comparatively, it is very well protected. It is very unlikely a 20mm HE round would reach the fuel tank, it would take a shot almost strait up from the bottom or at 90 degrees off to either side.



A single 20mm AP round to the fuel tank would blast the Corsair down from the sky, and a 20mm Hispano AP round could easely reach the Corsair's internal fuel tank ![/quote]

The F4U-4 had over 290 lbs of armor plate and was rated "protected" from the rear against 20mm fire. An HE round would be very unlikely to penetrate deeply enough to reach the fuel tank. An AP round could reach it, but not as easily as the .50's will reach any of the fuel tanks on the Spit XIV.

No matter how you shake it, the Spitfire XIV is more susceptable to the guns of the F4U-4 than visa versa.


----------



## DaveB.inVa (Apr 19, 2005)

There are plenty of cases of radials flying home with lots of stuff missing, not only with fighters but bombers as well. You can't beat a round engine!!


----------



## Soren (Apr 19, 2005)

> It could also do negative G manuvers and a neg-G into a roll move that few other planes could match.



Many Fighters could match that RG, and that includes the Spit XIV. By 42 most Fighters could do these negative G maneuvers.



> As pointed out in the RAF study the CW wing was only of advantage to Spitfires with poorly functioning ailerons. Spitfire quality control was not good, planes differed wildly.



Thats ludacris !! And exactly the opposite of what other research results as found them to be ! 




> Hmmm... lets do the math....
> 
> Spit XIV = 8500 lbs / 242 sf = 35.12 lbs/sf
> F4U-4 = 12405 lbs / 314 sf = 39.5 lbs/sf
> ...



Hmmm.. yeah lets do the math "Correctly" this time.

* Empty weight Wingloadings and powerloadings: * 

F4U-4: 4,175.3 kg / 29.17 m2 = 143.13 kg/sq.m.
Spit XIV: 2,994 kg / 22.48 m2 = 133.18 kg/sq.m.
Spit XIV "CW": 2,994 kg(Actual weight would be lower) / 21.46 m2 = 139.59 kg/sq.m.

F4U-4: 2,350 hp / 4,175.5 kg = 0.56 hp/kg.
Spit XIV: 2,050 hp / 2,994 kg = 0.68 hp/kg.
Spit XIV "CW": 2050 hp / 2,994 kg (Actual weight would be lower) = 0.68 hp/kg.

* Loaded weight Wingloadings and Powerloadings: *

F4U-4: 5,633.6 kg / 29.17 m2 = 193.1 kg/Sq.m.
Spit XIV: 3,855 kg / 22.48 m2 = 171.4 kg/sq.m.
Spit XIV "CW": 3,855 kg (Actual weight would be lower) / 21.46 m2 = 179.6 kg/sq.m.

F4U-4: 2,350 hp / 5,633.6 kg = 0.41 hp/kg.
Spit XIV: 2,050 hp / 3,855 kg = 0.53 hp/kg.
Spit XIV "CW": 2,050 hp / 3,855 kg (Actual weight would be lower) = 0.53 hp/kg.

Its VERY clear who is the better T&B fighter, and who is not ! 



> Spitfire quality control was not good, planes differed wildly.



Hahaha !!   Yeah in 1940-41 !! 



> And those books are to be taken over the actual test reports? LOL!



RG most reports contradict each other ! These books are based on modern measuring methods ! 



> Both the Corsair and the P-51 were known to use combat flaps at high speeds. Very few other planes were able to do so.



Shiden, Bf-109, Frank etc etc all used combat-flaps. Also flaps will decrease speed nomatter how little you apply them, and the slower the Corsair goes the worse it turns ! (This is generally true for all U.S. aircraft)



> Why do you think they use the .50 sniper guns for anti-vehicle work?



Because your most likely going to hit thin metal at 90 degrees with "Uranium" bullets ! Thats right the Barrett uses depleted Uranium rounds against lightly armored viechles and such. At 60 degrees from vertical the normal .50 cal AP round will penetrate very little armor, and surely not a 1-1.5cm thick engine-block. (A typical European car's engine-block is normally 10-15mm thick, and 5-6mm at the thinnest areas)



> Again wrong! P-47's, Corsairs, and Hellcats took 20mm hits to the front of the engine and survived frequently durring WWII.



No again I am right ! Its amazing you will even mention this, as there's a Gigantic difference between being hit by a 20mm 128g "HE" shell with a V0 of 600m/s from a Type 99, than by a 20mm 160g "AP" shell with a V0 of 860m/s from a Hispano ! 

Jap Cannons werent at all effective against armored parts, and would penetrate very little ! On the other hand a Hispano AP round will take out a Corsair engine with a single shot !

An AP round from a Hispano cannon will go straight through the R2800 engine ! And if the engine doesnt blow up, it certainly is in such a bad shape that it will not be able to pull the plane through any evasive maneuvers. 



> What? You mean to tell me you can put magnesium burning at 4000 degrees and a strong oxidizer into a fuel tank with gasoline and not have it go boom? Wow when did the laws of nature change?



If that was the case, then it would have been alot smarter to just use small caliber fast firing machine-guns with API rounds for Fighter vs Fighter purposes. 

A self-sealing fuel tank hit by a 20mm Hispano round (AP or HE), will always go BOOM.



> The F4U-4 had over 290 lbs of armor plate and was rated "protected" from the rear against 20mm fire.



Yeah, "Jap" 20mm fire ! It wont last one bit against a Hispano hit !



> But also because the self sealing rubber/plastic compounds were superior



Source ?!



> Look at the chart - it clearly shows 10 minutes WEP + 10 minutes MP.



RG why would two books specifically about the Corsair underestimate the WEP time ?? (Im beginning to seriusly doubt these Internet documents !)


----------



## Anonymous (Apr 20, 2005)

Soren said:


> Hmmm.. yeah lets do the math "Correctly" this time.



Um, your math and my math are identical except you chose to use metric where I used english measurments? How does that make Your figures more "correct" than mine?

BTW: the R2800-18W made 2450 BHP, not 2350 BHP, though this makes only a minor difference, raising the F4U-4 p/w ratio to 0.44 hp/kg.

The best documented Spit XIV climb to 20,000 feet I've been able to find is 5.1 minutes, for a plane 100 lbs below standard takeoff weight. This compares to 4.9 minutes to 20,000 feet for the F4U-4 at full takeoff weight and sporting two capped pylons. And on top of that, US climb tests are done from brake off, British climb tests are usually done from wheels up, a difference of about 15-20 seconds. How do you explain this? And how is it that the F4U-4, with capped pylons, is also faster than the Spitfire at most altitudes (except very low, and even there the Spit is not much faster) up to 28,000 feet? And with the capped pylons removed, it is faster to over 30,000 feet, significantly so through most of the altitude range!

And to achieve this performance, the Spitfire is overboosting to +25lbs. The F4U-4 could also drive higher levels of manifold pressure, but no specs are available for that. This was simply a matter of the "purple passion" fuel being available.

And on top of that, the Boscomb Down tests used meticulously prepared aircraft flown by top test pilots, where the USN pilot handbook data is taken from active squadron aircraft, usually flown by 3 fresh flight school grads and one instructor. (British pilot instruction books were similar)



Soren said:


> > Spitfire quality control was not good, planes differed wildly.
> 
> 
> 
> Hahaha !!   Yeah in 1940-41 !!



WRONG! I already gave you the tests info in an earlier post in this thread. Boscomb Down Report No. A.&A.E.E./Res/179 - _*Mar. 23, 1943*_



> _{w.r.t. clipped wing effectiveness and the Report quoted which shows that it was plane dependant because of poor Q/A which Soren disputes.}_
> 
> *Soren said:*
> No according to most books about it.
> ...



Surely you are joking. What modern tests have been done to measure this? NONE! This was a British test with definitative results - the clipped wings were useful only on individual planes that rolled poorly, on other individual planes with non-clipped wings that did not roll poorly, the clipped wings gave no significant advantage in roll rate and reduced both climb and turn performance. Clearly the conclusion was that for future production, where better Q/A was expected, clipped wings were not advised.



Soren said:


> > Both the Corsair and the P-51 were known to use combat flaps at high speeds. Very few other planes were able to do so.
> 
> 
> 
> Shiden, Bf-109, Frank etc etc all used combat-flaps. Also flaps will decrease speed nomatter how little you apply them, and the slower the Corsair goes the worse it turns ! (This is generally true for all U.S. aircraft)



First off, as far as I know only the P-51 was able to drop flaps (5 degrees) at speeds above 350 IAS. The Corsair was one of the few planes that could drop flaps a few degrees at speeds above 300 IAS. Furthermore, as far as I know, only the Corsair and the Shiden had automatic flaps.

On the P-51, 5% flaps could be dropped with a relatively small increase in drag and a significant increase in lift/turn. On the Corsair, the flaps could be set to auto mode and would deploy to maximize a turn, very similar to what was done on the Shiden. It should also be noted that quite a few F4U-1's were lost or damaged because of this feature which, on landing could decide to retract the flaps at a bad moment, and as a result on earlier models this feature was usually disabled in the field.



Soren said:


> > Why do you think they use the .50 sniper guns for anti-vehicle work?
> 
> 
> 
> Because your most likely going to hit thin metal at 90 degrees with "Uranium" bullets ! Thats right the Barrett uses depleted Uranium rounds against lightly armored viechles and such. At 60 degrees from vertical the normal .50 cal AP round will penetrate very little armor, and surely not a 1-1.5cm thick engine-block. (A typical European car's engine-block is normally 10-15mm thick, and 5-6mm at the thinnest areas)



Umm, first off depleted uranium ammo is only used for special circumstances. The normal .50 API round is considered capable of destroying most vehicles with a single hit to the engine at ranges up to 1000 meters. Given the accuracy of the weapon, which is not sufficent to hit a man reliably at 600 meters, there is no way to count on a 90 degree hit.

A typical Euro car engine block is made of aluminum, so it may well be 15mm thick. But for a cast Iron block, this is excessively thick, even for an aircraft engine. Even so, a .50 API round would penetrate or at least crack a 15mm cast iron block even at striking angles of 60 degrees. Cast iron is not steel, it is not as strong, and it is much more brittle.



Soren said:


> > Again wrong! P-47's, Corsairs, and Hellcats took 20mm hits to the front of the engine and survived frequently durring WWII.
> 
> 
> 
> No again I am right ! Its amazing you will even mention this, as there's a Gigantic difference between being hit by a 20mm 128g "HE" shell with a V0 of 600m/s from a Type 99, than by a 20mm 160g "AP" shell with a V0 of 860m/s from a Hispano !



Boy, your data on these guns is way wrong. The Japanese Type 99-Mod2 20mm cannon, in service from 1943 on as the main IJN 20mm, was quite comprable to the Hispano, other than having an intial velocity of ~750 m/s (as opposed to 807 m/s). While this makes some difference, it is not nearly so huge as you indicate.

For the Hispano II, here are the real weights, velocties (measured at 90 feet), and penetration data:


```
Hispano II -                                s1     s2    s3    s4    plate   -  total
--------------------------------------------------------------------------------------
SAP/I -             133 grams - 853 m/s      |  5% |  24% | 36% |  9%  #  0%  -  74%
AP Mk.II -          140 grams - 807 m/s      |  7% |  16% | 22% | 24%  # 18%  -  87%
BALL -              125.5 grams - 860 m/s    |  4% |  11% | 11% | 72%  #  0%  -  98%
HE/I/T (fuse 254) - 120 grams - 868 m/s    All detonated at fuselage.  All frags except
                                             one spent on sheet 1; one spent on sheet 2.
HE/I (fuse 253) -   130 grams - 860 m/s    All detonated at sheet 1.  All frags spent
                                             on sheet 2.
```
Where test layout is a sheet of 24 gauge dural followed by four sheets of 6 swg mild steel followed by an 8mm HH armor plate at 2' spacings. Firing range = 200 yards, angle = 0 (perpendicular). Percentages show the weight of the rounds recovered behind each sheet/plate.
HE/I type rounds were found to cause fires in unarmored self-sealing fuel tanks (German) for 31% of hits.
Source: O.R.S. Ref. F.T. 260 - July 1942 - ORFORDESS RESEARCH STATION
Firing Trials of 20mm H.S. Ammunition Part I. Attack of Aircraft Targets.
M.A.P. Ref: SB 13888 dated 7.3.42 and 19.5.42 (with handwritten notes dated 23.12.42)

Clearly, while the AP ammo was able to penetrate 24mm of HH armor at 200 yards @ 0 degrees (perpendicular), when put into realistic aircraft conditions the penetration is drastically reduced. The report indicates this is because of the yaw of the round. Combine this with more realistic striking angles and the chances of penetrating even the minimum 9.5mm tempered armor of the F4U-4 is quite small.



Soren said:


> Jap Cannons werent at all effective against armored parts, and would penetrate very little ! On the other hand a Hispano AP round will take out a Corsair engine with a single shot !



Based on the info above it is extremely unlikely a Hispano round of any type fired from behind would penetrate to the engine. If it did, it would quite likely be mostly spent and do only limited damage. Only on hits from extreme deflection from the side, or from H2H attacks (foolish for the Spit given this matchup), would the Hispano round likely hit the engine w/o having to penetrate at least 18 gauge dural, probably at least one structural member, and then tempered armor plate (much better than HH) ranging from 9.5 mm to 19 mm.



Soren said:


> An AP round from a Hispano cannon will go straight through the R2800 engine ! And if the engine doesnt blow up, it certainly is in such a bad shape that it will not be able to pull the plane through any evasive maneuvers.



And a .50 round will penetrate the Griffon just as easily. But unlike the R-2800, almost every hit will result in a destroyed engine. Once the water jacket is breeched, the engine is finished, and the pilot is flooded with steam and cannot see. The R2800 can take a 20mm hit and even if it looses a couple of cylinders it can still likely generate good power for over a hundred miles.

Furthermore the Corsair supercharge and fuel system are much much less exposed than that of the Spit XIV. On the R2800 these all on the back of the engine, but on the Griffon the carb and one stage of the supercharger are on the top of the engine!



Soren said:


> > What? You mean to tell me you can put magnesium burning at 4000 degrees and a strong oxidizer into a fuel tank with gasoline and not have it go boom? Wow when did the laws of nature change?
> 
> 
> 
> If that was the case, then it would have been alot smarter to just use small caliber fast firing machine-guns with API rounds for Fighter vs Fighter purposes.



No, because the API round has to penetrate the fuel tank, and .303 class API rounds cannod reliably do that.



Soren said:


> A self-sealing fuel tank hit by a 20mm Hispano round (AP or HE), will always go BOOM.



Not hardly. AP is ineffective period.

For AP/I against an unarmored tank, no fires were generated out of 8 hits (4 above and 4 below the fuel level), evidently the incendiary did not ignite. Against a tank protected by 6 s.w.g. mild steel, of 2 hits above the fuel level 1 caused a fire, and of 14 below the fuel level 4 caused fires (one outside the tank on the exit hole - probably would not have started a fire on a flying plane). Against 8 s.w.g and 10 s.w.g. protection of 9 hits none started fires. Against 14 and 16 mm HH armor, approximately 20-30% of hits started fires. Against 18mm armor, only one of 20 hits caused a fire.

For HE/I/T against unarmored fuel tanks of 50 rounds 16 started fires, and for HE/I of 72 rounds only 24 started fires. For HE/I against 6mm HH armor 9 rounds caused 3 fires, against 8mm HH armor 12 rounds caused 5 fires, and against 9mm HH armor 5 rounds caused no fires.

As you can see, Hispano hits against fuel tanks did not mean a sure fire, in fact, the odds against a well protected fuel tank like on the Corsair would be quite small.



Soren said:


> > The F4U-4 had over 290 lbs of armor plate and was rated "protected" from the rear against 20mm fire.
> 
> 
> 
> Yeah, "Jap" 20mm fire ! It wont last one bit against a Hispano hit !



I've shown you that this is not true above.



Soren said:


> > But also because the self sealing rubber/plastic compounds were superior
> 
> 
> 
> Source ?!



I'll get into this some time soon. But it is a fact. US self sealing tanks at the start of WWII were better than anyone elses tanks at the end of the war.



Soren said:


> > Look at the chart - it clearly shows 10 minutes WEP + 10 minutes MP.
> 
> 
> 
> RG why would two books specifically about the Corsair underestimate the WEP time ?? (Im beginning to seriusly doubt these Internet documents !)



It's not an "Internet Document". Geeze I've given you the source, the US Navy FIA complaince website. What source could be more valid than the classified pilots handbook - used by pilots and mission planners. What is the point of giving documents to your pilots that are incorrect? Especially documents you never expect the public to see! I can see you doubting the 4th fighter group documents, or other documents where the data has been complied - but how can you "doubt" this? You're just being silly!

Because those books were written before the FIA compelled the US Navy to declassify and make available the actual data. The US military gave out Military Power or Normal power data to the public at the end of WWII for most fighters - they didn't want to give away the real specs. Then being the paranoids that is their nature, they didn't declassify it until they were forced to when the FIA laws came into play, which require information to be made public after 50 years unless congress votes specifically to keep it secret. This is further confused by some data being published regaurding performance using lower grade fuel.

It is so clear you must be able to see it. Look at the chart (attached), most of the figures you commonly see associated with the F4U-4 are right there!

=S=

Lunatic


----------



## KraziKanuK (Apr 20, 2005)

Luni,

why do you claim specs for a 25lb boost Spit when it is for an 18lb boost Spit? The XIV was only cleared for 21lb boost.

The a/c tested was 8400lb. Take-off weight is 8288.5lb (StH) which does not include the pilot.

Clipping wings on the Spit was not done to poorly rolling a/c. Spits were produced with clipped wings until the end. No doubt you will say that QA was crappy to the end now.

"meticulously prepared aircraft"  

Most were modified from other marks and well used. Where do you think that data came from in the Pilot's Handbook for the F4U? From factory/Service prepared a/c tests.

So the Americans never produced 'rogue' a/c. Now why were a/c tested before delivery? Give me a break.

The 109 had infinite flap adjustment from full up to full down.


----------



## Anonymous (Apr 20, 2005)

KraziKanuK said:


> Luni,
> 
> why do you claim specs for a 25lb boost Spit when it is for an 18lb boost Spit? The XIV was only cleared for 21lb boost.



I used the most favorable data for the Spit XIV I could find, which included +25 lbs speed data for the XIV at low altitude, +18 lbs speed data above that. Refs below:

http://www.spitfireperformance.com/spit14speedns.jpg
http://www.spitfireperformance.com/spit14+25lbs.jpg
http://www.spitfireperformance.com/jf319.html




KraziKanuK said:


> The a/c tested was 8400lb. Take-off weight is 8288.5lb (StH) which does not include the pilot.



Loaded weight is given as 8500 lbs, takeoff weight was 8400 lbs.



KraziKanuK said:


> Clipping wings on the Spit was not done to poorly rolling a/c. Spits were produced with clipped wings until the end. No doubt you will say that QA was crappy to the end now.



I did not say it was done to tested planes only in the field, only that tests indicated that it gave no benifit to those units that rolled well without clipped wings. In the field, it was done or not done on a squadron by squardon basis, or in some cases I think as requested by the pilot on later Spits with the newer wings with removable/attachable wingtips.

Yes, Q/A was not great right up through 1943 and into 1944. Britian was very pressed to maximise production even at the cost of quality. It is not uncommon to see comments by Spitfire pilots reassigned to P-51's about the much better fit and finish quality of the P-51. The same is true concerning the RR vs. Packard Merlins.



KraziKanuK said:


> "meticulously prepared aircraft"
> 
> Most were modified from other marks and well used. Where do you think that data came from in the Pilot's Handbook for the F4U? From factory/Service prepared a/c tests.



That is wrong. They came from operational aircraft, usually from a training base which had recently recieved the new aircraft, or from a US based squadron (either new or on rotation) which had just recieved new aircraft.

How do I know this? My Dad conducted these tests for several USN aircraft, both when a flight instructor at Pensacola and as a squadron CO. Four planes would be taken up, the best and worst were normally not counted and the mid two averaged unless one had mech problems, in which case the other 3 were averaged or the test was voided and redone. The aircraft were in good, relatively new condition, but they were not polished up specially and the engines were not tweaked for the test. The intent was to give the pilot a reasonable idea of what he should expect from the aircraft, not to find out what the maximum potential might be (as in the Boscomb Down tests) or to make the company look good (as for Mfg tests). Again, I would point out that I believe the manuals given to actual British pilots most likely reflected the same info w.r.t. the plane in question, rather than the Boscomb Down info which presents unrealistically favorable stats and would be misleading. It makes no sense to give your pilots info which might get them killed if they rely upon it in combat.



KraziKanuK said:


> So the Americans never produced 'rogue' a/c. Now why were a/c tested before delivery? Give me a break.



Yes they most certianly were tested, much more thorougly and to much more stringent acceptance standards than the Spitfires. It was a matter of priorities, not capability. The British simply needed as many planes as fast as possible, so quality suffered in some respects and the acceptance standards were lower. It's not a dig at the British Kanuk, it just reflects their priorities which differed from the American priorities. And this is not to say that no "rouge" a/c slipped by American Q/A, just that acceptance standards were higher because the US had the luxory to be more demanding than the Brits did.



KraziKanuK said:


> The 109 had infinite flap adjustment from full up to full down.



How is this relevant to my comments on flaps? I never said anything about the flap control of the 109, other than that it was not automatic and as far as I know it had a maximum deployment speed of well under 300 IAS (like almost every other WWII fighter).

=S=

Lunatic


----------



## Soren (Apr 20, 2005)

> Um, your math and my math are identical except you chose to use metric where I used english measurments? How does that make Your figures more "correct" than mine?



Because I applied Power-loading aswell !  



> BTW: the R2800-18W made 2450 BHP, not 2350 BHP, though this makes only a minor difference, raising the F4U-4 p/w ratio to 0.44 hp/kg



All my books, both specifically about the plane and those that mention only its stats, quote 2,350 hp. While only one book quotes 2,450 hp just once, and then a stretch down the page it quotes 2,350 hp. So since the far majority (if not all) of the latest books about the plane quotes it as being 2,350 hp, it has to be 2,350 hp. 



> Yes they most certianly were tested, much more thorougly and to much more stringent acceptance standards than the Spitfires. It was a matter of priorities, not capability. The British simply needed as many planes as fast as possible, so quality suffered in some respects and the acceptance standards were lower.



Im going to need a source that specifically says this, cause that is simply just a big load of Bias !



> Yes, Q/A was not great right up through 1943 and into 1944. Britian was very pressed to maximise production even at the cost of quality. It is not uncommon to see comments by Spitfire pilots reassigned to P-51's about the much better fit and finish quality of the P-51.



Please quote example !



> WRONG! I already gave you the tests info in an earlier post in this thread. Boscomb Down Report No. A.&A.E.E./Res/179 - Mar. 23, 1943



Show me the original document, and all additional pages.

I own practically every newly published book about the Spitfire and all its versions, and your absurd claim of poor quality isnt at all mentioned in any of them. All that is mentioned, is that quality was slightly decreased during BoB.



> Because those books were written before the FIA compelled the US Navy to declassify and make available the actual data.



RG, the books are written in 1996 and 2002 (Plus others from year 2000 and beyond), so there goes that theory !

------------------------------------------------------------------------------------

About the Climb rates;

RG please tell me how the Corsair with inferior Power and wing-loading stats, can outclimb the Spit XIV.e wich has much superior Power and Wing-loading stats ?! Thats right, it CAN'T !!

Not only does the Spit's engine and propeller have to pull alot less weight, but the wing also carries alot less weight pr sq.m ! = Better climb and turn-rate ! 
Now if your going to deny this, then your denying the bloody laws of gravity ! 

Also the best initial Climb rate the F4U-4 can achieve is 4,170 ft/min, times four this doesnt even equal 20,000 ft ! Now your not going to tell me that the F4U-4 can climb at 4,170 ft/min for a whole 20,000 ft now are you ?

The F4U-4's real Climb rate time is 7.5 min to 20,000ft as quoted in all specific books about it, and the Spit XIV's climb rate is 7.0 min to 20,000ft.



> I'll get into this some time soon. But it is a fact. US self sealing tanks at the start of WWII were better than anyone elses tanks at the end of the war.



Sorry but now your babbling. First you claim the U.S. fuel-tanks were better than all others, and then you change it to "_*At the start of WWII *U.S. Fuel-tanks were better than anyone elses tanks *at the end of the war*_" Wich makes me go " Huh ?"  



> Not hardly. AP is ineffective period.



A 20mm Hispano AP round will blow a selfsealing fuel-tank with one shot RG, as the caliber and force of the round is simply to great for the tank to hold !

Also RG, if the Hispano AP round will go through 24mm of 0 degree "armor" at 400y, then it will also go through the Corsair's tail section and straight into the engine ! The thin layer of skin on any WW2 fighter has absolutely no effect on a 20mm AP round comming at 807m/s ! 

And as for the difference between being hit by a .50 cal and a Hispano; Look very closely at the pic at the bottom of the page ! (You can fit more than twenty to thirty .50 cal rounds inside that hole !)

It is quite clear that single 20mm Hispano hit on one of the Corsairs wings, and it is uncapable of making any evasive manuevers ! Also if the Cosair gets hit on the tail by the Hispano, its likely going to lose alot of it !


----------



## Anonymous (Apr 21, 2005)

I'm going to break this up into multiple replies. First.. about the F4U-4.



Soren said:


> > BTW: the R2800-18W made 2450 BHP, not 2350 BHP, though this makes only a minor difference, raising the F4U-4 p/w ratio to 0.44 hp/kg
> 
> 
> 
> All my books, both specifically about the plane and those that mention only its stats, quote 2,350 hp. While only one book quotes 2,450 hp just once, and then a stretch down the page it quotes 2,350 hp. So since the far majority (if not all) of the latest books about the plane quotes it as being 2,350 hp, it has to be 2,350 hp.



To answer this I'll have to go into a bit of Corsair history. You can contact the Vought Heritage museum and purchase copies of the orginals of these documents since I'm sure nothing else will convince you of their authenticity. Please excuse the poor quality of the scans.

In 1943 till the end of 1944 the USA had intended to supply the USN and USAAF with 150 octane fuel in the PTO by early 1945 at the latest. Based upon this, Vought performance testing and USN acceptance testing of the F4U-4 were based upon use of 150 octane fuel and a Combat Power (WEP) rating of 70 inches manifold pressure. And it turns out I do have the specs for that! The following Vought document pages reflect this performance:














As can be seen form these pages, at SL the climb rating was 2530 BHP, the max level speed rating was 2540 BHP, and the rated power was 2650 BHP! The 2050 BHP figure for the Griffon is rated power.

Anyway, near the end of 1944, given the huge performance gap that had become apparent between US and Japanese aircraft, the decision was made not to divert any 150 octane fuel to the PTO until the war in Europe was won. In April 1945, Vought and the USN issued revised data reflecting 115 octane performance, as shown below:










As can be seen in the chart the power rating at SL is about 2450 BHP for speed and 2300 BHP for climb. Rated power is about 2350 BHP.

Now, you really don't think it is legitimate to compare the Spitfire XIV using 150 octane fuel while the F4U-4 is using 115 octane fuel do you?

It would be quite legitimate to use the 2650 BHP figure for this comparison, and the 2540 BHP figure is totally reasonable. 2450 BHP is the proper 115 octane fuel performance figure.

=S=

Lunatic


----------



## Anonymous (Apr 21, 2005)

Soren said:


> Show me the original document, and all additional pages.



Sure - I will expect you to present such data upon request as well! 8) 

-------------------------------


----------



## Anonymous (Apr 21, 2005)

Soren said:


> > Yes they most certianly were tested, much more thorougly and to much more stringent acceptance standards than the Spitfires. It was a matter of priorities, not capability. The British simply needed as many planes as fast as possible, so quality suffered in some respects and the acceptance standards were lower.
> 
> 
> 
> Im going to need a source that specifically says this, cause that is simply just a big load of Bias !



No it is not. The whole production methodology of the Spitfire was poorly oriented to good quality control. Each Spitfire was built pretty much in one spot, side by side with other units. The people building one Spitfire were different than those building the one next to it, and so were the tools they were using. Each such variance leads to variations in quality. Look at the photos below (which are on my webspace and will have to be removed for copyright reasons soon):














You can see the classic British production system that is known for poor quality control. US aircraft were produced on "modern" production lines:










The workers did their jobs on each plane and then it moved on along a track to the next worker(s). Thus the workers were much more specialized, and uniform quality could be maintained. If there was a problem with how some part of the plane was assembled, it was pretty easy to track it down to one of 3 sets of employee's that manned that assembly station and straiten it out. Also, the next assembly station would catch the poor workmenship immeadiately.

You are making way too much out of my comment about the variance in quality of Spitfire manufacture. I'm not saying the planes were shoddily built, but rather that there was somewhat less attention to minor details and the production method did not generate the kind of uniformity that US production methods did. And also they were under more pressure to produce quickly in an environment not well suited to it.

Seriously, there is no disputing that when it came to mass production during the WWII time frame the USA was the absolute master both in terms of quantity and quality.

---------------------------------------------------------------



Soren said:


> > Because those books were written before the FIA compelled the US Navy to declassify and make available the actual data.
> 
> 
> 
> RG, the books are written in 1996 and 2002 (Plus others from year 2000 and beyond), so there goes that theory !



If that is the case they they are based on very poor research. Or they are confining thier figures to 115 octane fuel since that is what the Corsair used until the very last couple of months of the war (carrier Corsairs got 150 octane fuel for Kamikaze intercept duty).

------------------------------------------------------------------------------------



Soren said:


> About the Climb rates;
> 
> RG please tell me how the Corsair with inferior Power and wing-loading stats, can outclimb the Spit XIV.e wich has much superior Power and Wing-loading stats ?! Thats right, it CAN'T !!
> 
> ...



First off, the R-2800 @ 70" boost has a much better HP curve for altitude than the Griffon 65. It produced 2400 BHP or more for climb all the way up to about 16,500 feet and is still producing 2200 BHP as it passes through 20,000 feet. It's huge supercharger was capable of producing nearly the full 70" over a much wider range than the Griffon's supercharger could even sustain +18 lbs boost, let alone +25 lbs.





(blower and engine)

Second, the F4U-4 prop 13'2" forbladed prop is more efficient than the Spitfire's 10'5" five bladed prop. The 5 bladed prop gives some advantage at very high altitude, but to almost 30K the Corsair prop is better.

Third, the F4U-4 wings produce more lift than the very thin Spitfire wings.

And if you look at the USN charts it is clear that the initial RoC is about 4800 fpm, not the 4170 fpm you quote. It remains at 4800 fpm till over 10,000 feet and then drops off to 3800 fpm at 20,000 feet. I must admit Vought charts do not look quite so favorable, showing about a 4500 fpm climb to 10K, but it still shows 20k in 5 minutes. I'll try to post that chart tommarow (actually later today  )

Look at my previous post. Both Vought in 1944 and the USN in 1946 give very similar data. I really don't see how you can argue that the USN data is not correct.



Soren said:


> The F4U-4's real Climb rate time is 7.5 min to 20,000ft as quoted in all specific books about it, and the Spit XIV's climb rate is 7.0 min to 20,000ft.



Yes, the F4U-4 climb to 20K was 7.5 minutes - UNDER NORMAL POWER! At 70" boost it was 4.9 minutes. Both Vought and the USN confirm it.



Soren said:


> Sorry but now your babbling. First you claim the U.S. fuel-tanks were better than all others, and then you change it to "_*At the start of WWII *U.S. Fuel-tanks were better than anyone elses tanks *at the end of the war*_" Wich makes me go " Huh ?"



This was one of the things the USA focused heavily upon prior to the war as part of the attempt to build bombers so tough they could fight off enemy fighters w/o escorts. German self-sealing tanks were poor (the synthetic rubber stuff in them turned to powder at altitude), and the British just started into self-sealing tanks at the start of the hostilities and borrowed US tech early on - but their fighters were too small to support the full setup. Niether the Russians or the Japanese had much in the way of ss tanks throughout the war.



Soren said:


> > Not hardly. AP is ineffective period.
> 
> 
> 
> A 20mm Hispano AP round will blow a selfsealing fuel-tank with one shot RG, as the caliber and force of the round is simply to great for the tank to hold !



If it can reach it.



Soren said:


> Also RG, if the Hispano AP round will go through 24mm of 0 degree "armor" at 400y, then it will also go through the Corsair's tail section and straight into the engine ! The thin layer of skin on any WW2 fighter has absolutely no effect on a 20mm AP round comming at 807m/s !



Grrrr. At the muzzle it's got 807 m/s velocity. By 400 yards its down to about 600 m/s. Then it has to pass through the duraluminum skin, half a dozen ST24 brackings, and then 19mm of tempered steel rear armor plate, and then it will probably have to pass through at least two more sheets of ST24 and possibly 9.5 mm of bulkhead armor before it reaches the fuel tank. Even if it misses the 9.5 mm bulkhead armor, it's not going to reach the fuel tank.

As I showed you before, AP penetration drops radically if it has to pass through anything prior to striking the a plate, even at 0 degrees. Less than 20% of Hispano AP rounds penetrated just 8 mm of HH armor plate at 0 degrees from just 200 yards after passing through a thin sheet of dural and 4 thin sheets of mild steel, and 55% were stopped before passing through the 4th thin sheet of mild steel! How is it going to make it through 19mm of much better tempered plate after passing through all the structural support in the rear fuselage of the Corsair? It's not!



Soren said:


> And as for the difference between being hit by a .50 cal and a Hispano; Look very closely at the pic at the bottom of the page ! (You can fit more than twenty to thirty .50 cal rounds inside that hole !)



Well, I don't believe that is a Hispano hit. Looks like an AA hit to me. The amount of HE held in a Hispano HE round is about 10 grams (varies depending upon exact round type). 10 grams of HE is about the size of three sugar cubes. When HE explodes, it expands to about 1000x its size. 3000 sugar cubes is about a block 15 x 15 x 15 sugar cubes, or roughly the size of a small to average grapefruit. That hole is bigger than that.

This time it's your turn - produce the proof that is a Hispano hit!



Soren said:


> It is quite clear that single 20mm Hispano hit on one of the Corsairs wings, and it is uncapable of making any evasive manuevers ! Also if the Cosair gets hit on the tail by the Hispano, its likely going to lose alot of it !



You vastly underestimate the toughness of the Corsair's construction. Do not compare it to a German fuselage section, they are not comprable.


----------



## Soren (Apr 21, 2005)

> No it is not. The whole production methodology of the Spitfire was poorly oriented to good quality control. Each Spitfire was built pretty much in one spot, side by side with other units.* The people building one Spitfire were different than those building the one next to it, and so were the tools they were using.* Each such variance leads to variations in quality.



You can't be serius RG !! By 1942 all the men working on those aircraft were more than qualified. Also tools didn't differ, only under a very powerful microscope !  Oh and btw, English and German tools were the best in the world at that time !

Also you still havent provided any source that specifically verifies your claim !



> Seriously, there is no disputing that when it came to mass production during the WWII time frame the USA was the absolute master both in terms of quantity and quality



Not in quality. 



> Grrrr. At the muzzle it's got 807 m/s velocity. By 400 yards its down to about 600 m/s.



And the merit of this comment is ? The Hispano AP round will penetrate 24mm of 0 degree "ARMOR" at 400y (This is at approx. 600m/s), so at 0-400y it will also reach the Corsair's engine !

Anyhow the Hispano's HE rounds would be more than enough, and would inflict lethal damage to the Corsair after just a couple of hits !



> Second, the F4U-4 prop 13'2" forbladed prop is more efficient than the Spitfire's 10'5" five bladed prop. The 5 bladed prop gives some advantage at very high altitude, but to almost 30K the Corsair prop is better.



The Corsair's prop isnt at all superior !



> Third, the F4U-4 wings produce more lift than the very thin Spitfire wings.



First of all the Spit's wings arent thin, only at the tips ! Also the Spit's wings are very wide, wich helps produce more lift.

Secondly the Corsairs wings won't produce more lift than the Spit's, as they are bent, and at the inner part of the wing on the leading edge are intakes, all of wich reduces lift ! Plus the Corsair's wings are also thin at the tips, just like the Spit's (Although not equally thin). Additionally the Spit's wings have an airfoil shape wich is more "Curved" than the Corsair's, wich in return equals more lift pr m2.

So both the Spit's Wing and lift-loading is better !

----------------------------------------------------------------------------- 

Anyhow lets go ahead and try to compare the two Fighters with your stats:

*F4U-4 Corsair loaded Wing and power-loading:* 

Wing-loading: 5,633.6 kg / 29.17 m2 = 193.12 kg/sq.m.

Power-loading: 2,650 hp / 5,633.6 kg = 0.47 hp/kg.

*Spitfire Mk.XIV loaded Wing and power-laoding:* 

Wing-loading: 3,810 kg / 22.48 m2 = 169.48 kg/sq.m.

Power-loading: 2050 hp / 3,810 kg = 0.54 hp/kg.

Even with these outrageous stats the Spit XIV is still very much superior !


----------



## Anonymous (Apr 22, 2005)

Soren said:


> > No it is not. The whole production methodology of the Spitfire was poorly oriented to good quality control. Each Spitfire was built pretty much in one spot, side by side with other units.* The people building one Spitfire were different than those building the one next to it, and so were the tools they were using.* Each such variance leads to variations in quality.
> 
> 
> 
> You can't be serius RG !! By 1942 all the men working on those aircraft were more than qualified. Also tools didn't differ, only under a very powerful microscope !  Oh and btw, English and German tools were the best in the world at that time !



You are showing you do not understand industrial production methodology of the period. There were basically two systems in place. One was the traditional craftsmen method as had been used in Europe for centuries where each item is manufactured individually by a small team of workers who encompass all the necessary skillls, which was the primary system used in Britain. The other was the Modern Assembly line system as invented by Henry Ford and used in USA, where the product moves along a conveyor system and small teams of workers with very specialized skills work on each item as it passes through their station doing a very specific set of tasks. Each system has advantages and disadvantages.

The advantage to the European system was that you could get a level of "hand made" craftsmenship that tends to be missing or to feel artificial in the assembly line system, though this is usually not advantagous for mass-production items. The disadvantage is that quality variance is high. Often, two "identical" units cannot swap parts. Another disadvantage is that quite often the records regaurding who really did what in a busy factory were not accurately maintained, so if down the line it was found certain units had a common defect, it was very hard to figure out who was responsible so they could be instructed on how to correct the defect.

The advantages to the assembly line system were speed of production, uniformity of production, and the minimization of the skill requirement for labor. The disadvantage was that a defect that did slip through the q/a process tended to apply to most or all the units produced - there were fewer people involved in the production process capable of spotting such a defect since skills did not overlap so much as in the European system. However, when a defect was identified it could usually be tracked down to a few responsible individuals. Typically for US plants which ran in 3 shifts, the shift making the error could be identified and the problem rectified rather easily. However in a few cases, such as the US AN-M1 and a large part of the AN-M2 Hispano production, the flaw in the breech clearances was endemic at the managment/engineering level which resisted taking responsibility and as a result a huge number of unreliable guns were produced.

As far as the English and Germans having the "best tools in the world" at that time this is only true when looked at in a small context. Yes, the British an the Germans did have some advanced tools, but to a very large degree these were advanced versions of tools dating back to the 1700's, known as "shaper" tools, which are simplistically described as very advanced grinders.

Shaper tools require extremely skilled "guildsmen" who spent their lives learning how to operate them to produce precision components. Even then, because of the individual nature of the crafting process there was inevitable variation in the results. And because of the skill required to operate them, simply adding more tools to the production floor does not result in a proportional increase in output of quality components since they will inevitably be operated by less and less skilled craftsmen. Shaper tools were also usually large and expensive.

To understand what was happening at this time you really have to study industrial history in the period from about 1600 (or earlier) through the end of WWII (or beyond). Europe, including both England and Germany, was based upon the crafts guild system. Most skilled craftsmen were born into the trade guild and spent 10 years or more from an early age as an assistant, then another decade or two as a journeyman, and then if they were deemed worthy became "masters" of their respective trade guild. These guilds dominated European industry and controlled its development, and they were very careful to protect thier interests, much like the Medical Doctors of today. They were extremely resistant to both technology and processes which might diminish the importance of the skilled craftsmen, and they had tremendous political power. Most guilds supported the other guilds, and had an unwritten but very well established agreement not to encroche into one anothers specialties. The end result for the machining industry was that while tools did improve over time, they were almost always simply improvements to the tools that proceeded them allowing the operator to do more and more precise work and they were almost never focused on reducing the skill required of the operator. Another issue was the education system. European guilds were generally resistant to outsiders and Universities were generally open only to the very rich, mostly nobility and not focused on such mundane tasks as industrial engineering.

So now we come to the American industrial experiance. During colonial times, very few large scale industrial tools were imported into the colonies. They were expensive, required skilled craftsmen who generally did not wish to leave their well established lives in Europe (mostly England), and it was in conflict with British policy to even allow significant industrialization of a colony since the whole idea was the colony was to trade raw materials for finished goods produced in England. After the Revolution, the British went further - banning the sale of machine tools to the USA both from British and other European sources (they'd be confiscated as contraband by British ships), and this ban was not lifted until after the Civil war.

So for the most part the USA had to build its own machine tools. Because there were relatively few skilled craftsmen from Europe, the exception being a few who'd fled European religious intolerance without their large tools, there was a strong motivation to develop machine tools that required much less skill on the part of the operator and there were no established trade guilds to oppose this. Because, compared to Europe, labor in general was scarce in the USA, there was a general motivation to reduce the labor input to production. Another factor influencing American machine tool development in the 1800's was the need to keep the size and cost of the machines relatively low by comparison to European machines. These factors led to major innovations. And US Universities were much more open to "commoners" and also open to industrial engineering. Thus the sons of craftsmen and people who had a real need for products had the oportunity to pursue solutions at Colleges and Universites.

A good example is Eli Whitney. The son of a Massachusetts farmer, he would never have had the opportunity to become an inventor in Europe. He made nails for spare cash as a teenager, a guild law violation in Britain at the time, and developed techiques to mass produce nails with a reduced labor input. He worked on his fathers farm and taught school to earn money which he saved to pursue an advanced education at Yale from which he graduated at the age of 27 in 1792. In 1794 he patented the Cotton Gin, an invention for which he was never compensated after fighting in the courts to collect on his patent for a decade. He gave up on the Cotton Gin and the South and headed back to New England in about 1805.

In New England Whitney leveraged his fame as inventor of the Cotton Gin to aquire a Federal contract for 10,000 rifles, even though he had no facilities to produce them and no past experiance in manufacturing guns. And in pursuing this project he laid the foundation for what was to become known as the "American system of manufacture", which differed tremendously from that of Europe. European rifles (and American rifles up to that time) were constructed entirely by hand as a craftsmen's item. There was no parts interchangability between any two rifles. Whitney changed that by creating a template system which allowed an _unskilled laborer_ to make precision parts that exceeded the quality of all but the most skilled craftsmen and which were identical to those of other rifles allowing parts interchangablity. And thus was the milling machine invented.

The milling machine was just one of a host of inventions that were part of the American industrial revolution of the 1800's. The concept of making it possible for unskilled or low-skilled labor to produce high quality products was unique to the USA.

By WWII, American automated machine tools were far far in advance of those of Europe. The German's were further along than the British in terms of tools and production techniques, but still no where near as advanced as the USA. Multiple operation machine tools in the USA were much much more complex than those of Europe, often allowing a piece of metal to be placed in the machine and almost no operator action needing to be taken to produce the component. No other country had the "gang of saws", or the "centerless grinder". Sundstrand centerless grinders were transfered at British request to Napier from the Pratt&Whitney to make the unreliable SabreII reliable - these were developed by P&W specifically for the R2800(c) and the transfer delayed the R-2800(c), and thus the P-47M, P-47N, F4U-4, F7F, and F8F, by at least 4 months.

The point is American manufacturing was much more advanced than European manufacturing. While on a unit basis, the European system could produce an aircraft of comparable quality, on a mass production basis it could not. Either production quantity or quality had to be sacrificed relative to the manpower inputs involved.



Soren said:


> Also you still havent provided any source that specifically verifies your claim !



When British pilots got into a P-51 they used to say it was a "cadilac of the sky" because of the noticable quality of the construction, and commented that the Spitfire cockpit felt crudely built by comparison.

Well, it's been over 20 years since I studied industrial economics as part of my managment science major and history minor in college. I know this to be a fact, but finding any "proof" of it that will satisfy you on the web is like looking for a needle in a corn field. It is too removed from the common interest to be easily searched for - and who wants to write a book about such a topic? But I am sure I will find something eventually and I'll post it.



Soren said:


> > Seriously, there is no disputing that when it came to mass production during the WWII time frame the USA was the absolute master both in terms of quantity and quality
> 
> 
> 
> Not in quality.



Yes in quality. In terms of mass production quality the USA had no peers in WWII. The production of ships alone dwarfs the total production of all other nations combine in WWII.

Lets look at single engine fighter production. Germany was able to produce what - 45000 Bf109's and 20000 FW190's in WWII? Britain produced 20000 Spitfires (1000 of which used US built merlins), 2500 Seafires, 13000 Hurricanes, 3300 Typhoons, and 400 Tempests (note: many US parts were used in British fighters). So Germany was able to produce about 65,000 and Britain about 40,000 single engine fighters over the course of about 6 years. This compares to US production of 9590 P-39's, 14587 P-40's, 15685 P-47's, 15484 P-51's, 3271 P-63's, 7596 F4F's, 12274 F6F's, and about 6500 F4U's, for a total of 85,000 single engine fighters, the great great majority of which were produced in _just 3.5 years_!

=S=

Lunatic


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## KraziKanuK (Apr 22, 2005)

Some corrections Luni.

109 production was not 45,000 but 33,000.

In the Pacific, it was 145PN fuel, not 150PN fuel, and it arrived very late.

The RR Merlin, whether by RR or BY one of the other UK manufactures, was the preferred engine, not the Packard Merlin. The Packard was not that reliable.


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## Schöpfel (Apr 22, 2005)

Here you go Lunatic, wrap yourself in this:


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## Anonymous (Apr 22, 2005)

KraziKanuK said:


> Some corrections Luni.
> 
> 109 production was not 45,000 but 33,000.



You are correct, I used the 45,000 number without verifying it. However there were actually 39,000 109's built during the WWII period - 6000 were two seat trainers.



KraziKanuK said:


> In the Pacific, it was 145PN fuel, not 150PN fuel, and it arrived very late.



In 1943/44 the intent was to divert 150 grade fuel to the PTO. Later, as I said, this plan changed. I agree the high test fuel did not arrive until very late - about July 1945 with a few minor exceptions earlier.

The fuel rating system is kinda impossible to judge. As you probably no, there is really no such thing as 150 octane fuel - 100 is the highest possible "octane" rating.




KraziKanuK said:


> The RR Merlin, whether by RR or BY one of the other UK manufactures, was the preferred engine, not the Packard Merlin. The Packard was not that reliable.



Where do you find this. Everything that I've seen says the Packard Merlin was more reliable because it was made from superior alloys and it was built to more exact tolerances.


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## Anonymous (Apr 22, 2005)

Schöpfel said:


> Here you go Lunatic, wrap yourself in this:



Looks a lot better than the one your wearing:






8)


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## Nonskimmer (Apr 22, 2005)

Nasty.


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## DAVIDICUS (Apr 22, 2005)

Oooh, that was nasty.

Someone pass the popcorn.


Seriously though, let's keep our exchanges civilized.


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## mosquitoman (Apr 22, 2005)

DAVIDICUS said:


> Oooh, that was nasty.
> 
> Someone pass the popcorn



Thanks, I could do with some right now


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## Gemhorse (Apr 22, 2005)

Wow, this is some 'discussion' you guys are having [I'll have some of that popcorn too!!..], which I'm finding extremely informative...Thankyou for the explanation of the merits of the Industrial histories and differences RG, I've found it very illuminating...

The mention of Packard Merlins stirred a memory, and I've tracked it down, it's actually concerning Lancasters in this instance....

Cliff Allen started at 21 as an Engine Fitter working on Lancasters for RAF No.'s 467,463[RAAF] and 617 Sqns. in WWII, and wrote;
''The wooden tool box issued to each mechanic contained a rachet screwdriver; a few open-ended spanners, which were too soft and soon useless; a hacksaw; file; engine brush; pliers and hand-vice; a set of BA spanners, also soft; and a feeler gauge...All these looked insignificant in the huge box...- When Lancasters entered service fitted with American Packard Merlins, highly sophisticated tool kits were supplied with them; but alas, only one of these ever reached the flights. This was kept in the Flight Office under the eagle-eye of our flight sergeant. NCO's in charge of groundcrews were alone authorised to use this toolkit, which contained the very versatile universal box spanner with attachments, and socket-heads, precision-made to fit aero-engine nuts bolts. A wide range of open-ended and ring spanners, toughened for the job they had to do, and a host of other useful gadgets, completed this masterpiece of engineering.
Secrecy kept these labour-saving devices locked away for some time until a hard-pressed groundcrew really needed them: then all of the flight knew of their existence, so the rule ''NCO's only'' was fixed...''

That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties, and in reading what you chaps are discussing, I have to concur that although both Allies had different manufacturing processes, there appears that American quality was of a very high standard. Where the Servicing process was different, the Commonwealth groundcrews were very thorough but lacked suitable equipment, the US groundcrews tended not to 'tinker' unless something was radically wrong; and possibly their Spares were more quickly accessible too. 

This is tough for me, I love both these aircraft !!...But I am respectful of both your comments, they are indeed enlightening, I don't think I could make a choice here.......


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## Nonskimmer (Apr 23, 2005)

Gemhorse said:


> That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties...


"Yeah", in the case of the RCAF. Grandad mentioned that the boys had a helluva time finding proper tools on occasion. Sometimes they'd just improvise, but they always managed to get the job done to keep the big birds in the air.
One thing he never mentioned were hidden specialty tool kits. If the fellas had found out about _that_, I'm pretty sure you'd have seen a few dead Warrant Officers lying around.


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## KraziKanuK (Apr 23, 2005)

RG_Lunatic said:


> KraziKanuK said:
> 
> 
> > Some corrections Luni.
> ...




109 construction was no more than 35,000 and that included Hungarian war time construction and Spanish post war construction. Where did you get this 6000 trainers? Not from WNr serial blocks I hope. There was only the G-12 built as 2 seat trainers and *NO MORE* than 500 were built(converted).

Fuel for the Pacific was 115/145 PN, to use the correct terminoligy. The lean-rich mixture should be shown.

Made to more exact tolerances.   Packards had tolersances *more* sloppy than the UK Merlins. That is the way assembly lines work > sloppy tolerance so everything fits. You reading material requires some broadening that does not toot the American horn so much.

The best thing about Packards was the tool kit that came with it.

A family friend, who passes away a couple of years ago was a ground crew on Mossies and then became flight crew. He stated that they dreaded getting a Mossie with Packards to fdly on a mission.


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## FLYBOYJ (Apr 23, 2005)

Nonskimmer said:


> Gemhorse said:
> 
> 
> > That's not the first time I'd read of this sort of thing, all Commonwealth Groundcrews may have had similar difficulties...
> ...



*As a maintainer by trade I must state that this is true even today!*


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## Nonskimmer (Apr 23, 2005)

As a shipboard electronics maintainer, I can tell you we've always had access to any specialty tools we needed. If not, you risk damaging the equipment and just maybe yourself or your buddies. There have been times when a tool or two may have been misplaced and we've had to improvise, but that's a far cry from deliberately withholding the proper tools from the maintainers. Especially during a war.


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## FLYBOYJ (Apr 23, 2005)

Nonskimmer said:


> As a shipboard electronics maintainer, I can tell you we've always had access to any specialty tools we needed. If not, you risk damaging the equipment and just maybe yourself or your buddies. There have been times when a tool or two may have been misplaced and we've had to improvise, but that's a far cry from deliberately withholding the proper tools from the maintainers. Especially during a war.



I guess you guys got to be extra careful because of your equipment


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## Nonskimmer (Apr 23, 2005)

True enough I guess, but even the mechanical gear has certain tolerances that have to be met. That often requires specialty tools like torque wrenches and such. It just irks me to think that the boys wouldn't have been given something necessary to the job, when it was in their possession the whole time. 

Still, they managed I suppose.


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## FLYBOYJ (Apr 23, 2005)

I know what you mean, I hate when someone uses a "calibrated elbow."


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## Anonymous (Apr 23, 2005)

Packard Merlins were made of superior metals. They were also made to more exacting tolerances - whether these were "looser" than the RR's I don't know, just that they were more consistant. RR's also lacked the cleanup that the Packards recieved, the flashing was not ground off the inside of the block for instance, where on the Packards it was.

Look at the number of "spares" per squadron... for the Brits, it was 20 planes per squadron to keep 12 flying. For the P-51's, it was 20 to keep 16 flying. Of course, there was more than engines involved but the engines were by far the biggest maintainence component.

=S=

Lunatic


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## trackend (Apr 23, 2005)

I'm not trying to stir the S... or anything as this is a genuine question RG do you think the location of the factory's would have had an influence on the production quality of the lumps, I don't know what the production figures are in terms of labour resources too productivity, but do you think having the threat of bombing had a direct influence on the need for speed over quality control?


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## Anonymous (Apr 23, 2005)

Soren,

About the BHP of the Spit XIV vs. the F4U-4. I've combine the Vought April 1944 graph with the Spit XIV graph on Mark William's 4th Fighter group website. While it could be argued that Vought's graphs are company graphs and therefore might overstate the power ratings some, the graph on Mark William's site gives no ref. to the orginal source and WE KNOW HE HAS A VERY HIGH PRO-SPITFIRE BIAS! Also, the graph represents performance from the Griffon 61, 65, 66, 85, 86, and 90 - only the 61 and 65 are relavent for WWII, so the Griffon power ratings are probably overstated. These are the only BHP graphs I can find, so they will have to do.






For the Spitfire I've show the BHP for +18, +21, and +25 lbs boost. The solid green line shows +21 lbs boost, and it is the relvant power output since the original graph indicates the mains/bearings were not strong enough to support +25 lbs boost and would have to be reinforced which never happened in WWII.

Evidently British max power ratings reflect takeoff power, which for the Griffon was ~2050 HP. As you can see the Griffon actually made about peak 2200 BHP at ~9800 feet. For the USN, the standard was "combat power" which was defined as power output at 15,000 feet, which gives ~2450 BHP for +70 lbs boost, about 2350 BHP for the lower boost setting used with lower grade avgas used in the PTO in early 1945.

Finally, the RPM for the Spitfire is 2750 rpm which is what is shown, and this is the maximum allowable RPM. The F4U-4 figures are at 2800 rpm and 70" of boost, though the engine could actually run up to 3000 rpm and up to 72" of boost (though this was never approved).

As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.

The Supermarine 369 Spitfire F XIV wings used NACA 2213 root and NACA 2209.4 tip airfoils. The Vought V-166 F4U Corsair used NACA 23015 root and NACA 23009 tip airfoils. Unfortunately the Spitfire aifoil data is not available in a windows program compatible format, I'm trying to figure out how to convert the data now but the software is not well documented. I can however put both up in a dos program (which I cannot screen grab), overlayed on top of one another, and it is very clear that there is only a little difference in the wing root airfoils (max chord point of the F4U sits a little further back from the leading edge, perhaps 5%), and ALMOST NO DIFFERENCE AT THE TIPS. Furthermore, the F4U wing chord is a bit longer at the root and quite a bit longer out beyond the guns.

When it comes to the props, the 5'2-1/2" inch blades of the Spitfire are 1'4-1/2" shorter than the 6'7" blades of the F4U-4. 4 x 1'4-1/2" = 5'6". Therfore the total blade length of the F4U-4 is a few inches greater than that of the Spitfire. Furthermore, the blades of the F4U-4 have a greater chord (i.e. they are thicker) and are more optimally shaped (they have no eliptical form to the leading or trailing edge and the chord does not taper off so quickly near the tips). And of course the prop becomes increasingly efficient the further it is from the hub.

=S=

Lunatic


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## KraziKanuK (Apr 23, 2005)

You do have your problems Luni. The boost for the Griffon was *21*ln NOT 22lb.


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## Anonymous (Apr 23, 2005)

trackend said:


> I'm not trying to stir the S... or anything as this is a genuine question RG do you think the location of the factory's would have had an influence on the production quality of the lumps, I don't know what the production figures are in terms of labour resources too productivity, but do you think having the threat of bombing had a direct influence on the need for speed over quality control?



Round trip distance from Calais to Birmingham was about 400 miles, well outside the range of the Bf109E/F to provide escort during early years of the war, and later the Germans didn't even try to bomb aircraft factories. I'm not sure how much night bombing of Birmingham took place, but I don't think the Vickers plant was ever hit by a bomb.

I certainly agree the British priority was for quantity over quality of production, within reasonable limits. As long as it was combat worthy, it was good to go. The logic was probably that 3 planes where one rolled well, one rolled satisfactorally, and one rolled not so well (but not horribly), were probably deemed to be of more value than two planes that rolled well.

Anyway, this whole part of the discussion just has to do with the fact that on the Spit III, V's (2), IX, and XII's (2) tested in March 1943 there was a very noticable variation between rolling quality from unit to unit. Those that rolled well with the non-clipped wings did not benifit signifcantly when tested with the wings clipped. However, those that did not roll well with non-clipped wings did benifit from having the wings clipped. This indicates a quality control issue - simple as that. Clearly the conclusion of the report was that wings should not be clipped on future versions of the Spitfire, which it must be assumed meant that they were indicating the quality variation needed to be rectified. Given that even on the Spit XIV wings were still being clipped, we must also assume this quality control issue was not fully rectified at least for Spit XIV production.

=S=

Lunatic


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## Anonymous (Apr 23, 2005)

KraziKanuK said:


> You do have your problems Luni. The boost for the Griffon was *21*ln NOT 22lb.



Grr... you are correct. I keep making that mistake  

Hey, it is not easy making these graphics. The stupid british chart puts altitude across the bottom and BHP vertical.

I'll fix the post and the graphic.

Thanks,

=S=

Lunatic


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## Soren (Apr 23, 2005)

RG_Lunatic said:


> As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.



You don't think so ??!!! 

RG a plain wing will always produce more lift than a bent one ! And those intakes on the Corsair's leading edge also reduces the lift even further.


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## Anonymous (Apr 23, 2005)

Soren said:


> RG_Lunatic said:
> 
> 
> > As for your comment about the wing airfoils - umm, I don't think so. I will try to post these soon.
> ...



The bent part of the wing will reduce lift a little. The oil cooler intakes will hardly reduce the lift at all, as that area of the wing root does not produce much lift in any case. Moving them was seriously considered, but tests showed it would not make a noticable difference.

The chord is longer, and the wing a little thicker, and that will make a difference.

But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.

=S=

Lunatic


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## Soren (Apr 23, 2005)

> The bent part of the wing will reduce lift a little.



It takes away much more lift than the small decrease of the Spits wing thickness in comparison to the Corsairs ! Those two bent wing sections take up a good part of the Corsair's wing-area !



> The oil cooler intakes will hardly reduce the lift at all, as that area of the wing root does not produce much lift in any case.



It still decreases the lift even further.



> The chord is longer, and the wing a little thicker, and that will make a difference.



The increase in thickness will hardly make any difference as the Spit's airfoil gets its max thickness earlier along the chord, and although this adds more drag it also adds more lift. 



> But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.



No but the difference is there, and the curvature is superior with the Spit's wings.

I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !


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## Schöpfel (Apr 23, 2005)

> I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !



Umm, its obvious, RG_Lunatic said it and *WE KNOW HE HAS A VERY HIGH PRO-AMERICAN BIAS! * Can't trust a word those arrogant american's say. It is funny though to think he thinks any American plane could out-turn a Spit. He probably thinks P-40 is better than BF 109 too  All British all liers and cheats, so you know that Griffon chart is nonsense too, probably a fraudulent forgery


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## Schöpfel (Apr 23, 2005)

> the graph on Mark William's site gives no ref. to the orginal source and WE KNOW HE HAS A VERY HIGH PRO-SPITFIRE BIAS! Also, the graph represents performance from the Griffon 61, 65, 66, 85, 86, and 90 - only the 61 and 65 are relavent for WWII, so the Griffon power ratings are probably overstated. These are the only BHP graphs I can find, so they will have to do.


You try to discredit this guy on one hand, then use his material on the other? Did you think to ask him for a reference before trashing his integrity or motives? Why didn't you find your own chart instead of using one from someone you distrust? Maybe you'll do anything on a forum to advance your *pro American agenda*? Did you intentionally overlook the Griffon 61 chart? http://www.spitfireperformance.com/spit21ads.jpg
This shows 2,050 at 8,000 ft. MS gear and 1,780 in FS gear, presumably without RAM. Still, I'm sure the Englander lies, just like the arrogant American.


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## Anonymous (Apr 23, 2005)

Soren said:


> > The chord is longer, and the wing a little thicker, and that will make a difference.
> 
> 
> 
> The increase in thickness will hardly make any difference as the Spit's airfoil gets its max thickness earlier along the chord, and although this adds more drag it also adds more lift.



The difference is minimal near the root, and practically non-existant near the tip. The Corsair airfoil is that of the tip from about the bend out, so there is little difference at all.



Soren said:


> > But what I was commenting on was your claim the basic airfoil shape for the Spit wings was somehow superior because of its curvature - there is very little difference at the root and practically none at the tip.
> 
> 
> 
> No but the difference is there, and the curvature is superior with the Spit's wings.



Not really. I've got the data, I'll post a pic soon (have to figure out how to render it still).



Soren said:


> I can't believe your trying to tell me the Corsair will turn with a Spit ! Its ludacris !



I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts. The Corsair also has a lot more active elevator and rudder surface area.

=S=

Lunatic


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## Gemhorse (Apr 23, 2005)

I don't think it's necessary to be abusive....we all have our respective patriotic feelings, but this is an incisive discussion that's drawing facts details from the past, as well as what has been revised and updated today. I for one think it's been bloody well presented so far, and as stated, I love both these aircraft....Back-up dude, and watch n' learn.....

Gemhorse


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## Soren (Apr 23, 2005)

> I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts.



At 0-350mph the Spit XIV very easely out-turns the F4U-4 ! At 350-450mph the difference is less pronounced, but the Spit still out-turns the Corsair.



> The Corsair also has a lot more active elevator and rudder surface area.



RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same.


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## Anonymous (Apr 23, 2005)

Soren said:


> > I'm saying the Spit does not badly out-turn the Corsair, especially at high speed which is what counts.
> 
> 
> 
> ...



The rudder and elevator control surfaces are bigger on the Corsair is bigger. Look at them carefully.


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## Soren (Apr 24, 2005)

RG look very carefully at these two pic's ! The Rudder on the Spit XIV is bigger ! (The pic of the Spit is actually taken at a bit longer distance.)


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## trackend (Apr 24, 2005)

Yup I agree with you Soren it definitely looks bigger on the Spite too me


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## the lancaster kicks ass (Apr 24, 2005)

close though, great pics too............


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## Anonymous (Apr 24, 2005)

Soren,

Those pictures are not at the same scale. The Spit XIV is 32 ft 8 in in length. The F4U-4 is 33 ft 8 inches in length. Yet in your photos the Corsair appears to be shorter than the Spitfire. The length of the moving part of the rudder is about the same for the two planes, but the Corsair's is taller by a fair amount.

=S=

Lunatic


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## the lancaster kicks ass (Apr 24, 2005)

well there has to be a document out there with the rudder size of these aircraft i mean you can get that info for the lanc??


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## Soren (Apr 24, 2005)

RG,

It is very clear that the Spit XIV's rudder area is bigger !


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## trackend (Apr 24, 2005)

Right scientific study here I just measured my swede from my nose to the back of my bonce 20cm so using this as a guide I measured the F4u pilots head at .5cm thus making the Corsair rudder approximately 
5 bonces wide X 7 bonces high.
The spitfire pilots head (allowing for the skid lid) is 4mm this makes the Spites rudder 5 bonces wide X 11.1 bonces high.
Therefore ip so facto the surface area of the Corsair is about 35 Square bonces where as the Spitfires is about 55.5 Square bonces even allowing for the fact that the Spites rudder is not rectangular it would still mean the Spitfire having a rudder several bonces larger than the Corsairs.
and before anyone says it my nose is only average in size.


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## the lancaster kicks ass (Apr 24, 2005)

that's just possibly the funniest thing i've ever read on this site


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## trackend (Apr 24, 2005)

I could get a more accurate measurement but i would need a mean average bonce size so Lanc if you and a few other guys can measure your heads from the tip of your nose to the back of your craniums we should be able to solve the problem of the tail size differential by using our heads.


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## Anonymous (Apr 24, 2005)

It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.

And the Corsair tail is taller too, even in the photos as given not accounting for the mis-scaling.


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## Soren (Apr 24, 2005)

RG_Lunatic said:


> It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.
> 
> And the Corsair tail is taller too, even in the photos as given not accounting for the mis-scaling.



How can the scale be off when both pics are presumably taken with the same camera, and when the two pilots are about the same size ? The picture isnt off scale or distorted at all, wich can clearly be seen by looking the wheels wich are perfectly circular.

Btw the Corsair's rudder isnt taller on the pic or in the real world at all, infact the Spit's rudder is a good deal taller


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## DAVIDICUS (Apr 24, 2005)

The lower portion of the Corsair's rudder (right above the fuselage) doesn't confer the same control surface benefit that the Spitfire's does at this location. This is because the air that flows over this portion on the Corsair's rudder is disturbed to a greater extent by the top of the fuselage behind the cockpit. That area is significantly above the lower portion of the Corsair's rudder.

The Spitfire's fuselage is a straight shot to the rudder. Only the cockpit disturbs the airflow.

Use each pitot's head as a rough measure of units for height and see how many head's high each is.

Hint ... The Spitfire wins this one on height of the rudder.


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## Anonymous (Apr 24, 2005)

Soren said:


> RG_Lunatic said:
> 
> 
> > It is clear the Spitfire is shown as being larger than the Corsair, simply scroll so you can see both on your screen. It should be over a foot shorter.
> ...


\

The Spitfire should be almost a foot shorter than the Corsair, but in those pictures its longer. Therefore it must be off in scale - OR THAT IS NOT A SPIT XIV!

Below I've superimposed a F4U scaled to about the right size (maybe a little small):






To be honest, I cannot tell which one has more rudder fin area. So I was mistaken in saying the Corsair had more.

But.... you said "*RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same.*" But, as you can see...






They are in fact not even close! The Corsair has far more rear stabalizer and elevator area than the Spitfire.

=S=

Lunatic


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## Anonymous (Apr 24, 2005)

Davidicus,

The F4U flies nose down, and the F4U-4 added a few degrees more attack to make it fly even more nose down, so the airflow is not as disturbed as that of the Spitfire which flies level. Not that this makes much difference.

=S=

Lunatic


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## DAVIDICUS (Apr 24, 2005)

I think it does make a difference as to the lowermost portion accounting for perhaps 13% (my estimate) of the total rudder area which has the dorsal portion of the fuselage in front of it. (Both aircraft's rudders have air flow disruption from the canopy to deal with although the Spitfire's appears more aerodynamic.)

As to the angle of attack in which the plane is oriented in level flight, I was not aware of this. Are you sure?

The P-47's transition from razorback to bubble canopy is illustrative here. The tail lost structural stability from the loss of the dorsal spine. The loss of the dorsal spine, however, also casused greater stress on the rudder as a result of increased unimpeded airflow to the rudder.


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## Anonymous (Apr 24, 2005)

The wing is angled up 4 degrees, and to counter natural lift (which the Spitfire does also) the nose must be angled downward even more to maintain level flight. On the -5 the engine was canted an additonal 2 degrees to provide ven more of a nose down flight attitude.

I think you can actually see this in side view photos, though the blue of the paint job does tend to obscure things a bit.

=S=

Lunatic


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## Soren (Apr 25, 2005)

> But.... you said "RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same." But, as you can see...



RG that illustration is *off scale *!! The Wing area of the Spit is 22.48m2 and the Corsair's is 29.17m2, giving a roughly similar visible wing area from above(The Corsair's wings are bent remember !)
wich obviously isnt apparent on your illustration ! 



RG_Lunatic said:


> Davidicus,
> 
> The F4U flies nose down, and the F4U-4 added a few degrees more attack to make it fly even more nose down, so the airflow is not as disturbed as that of the Spitfire which flies level. Not that this makes much difference.
> 
> ...



RG its the AoA of the wing that counts, and IIRC the Spit's wings has a better AoA than the Corsair's ! (Ever wondered why the Spit XIV's hub is pointing slightly downwards ?  )


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## Anonymous (Apr 25, 2005)

Soren said:


> > But.... you said "RG, the rudder on the Spit XIV is bigger than that on the Corsair, and the elevator's are about the same." But, as you can see...
> 
> 
> 
> ...



Okay, I double checked, and you are right the Vought diagram is not in proper proprotions. I was focusing on the tails so I didn't notice that. I've redone it using the USN diagram which is in proper proprotions:







The wing area is still not "similar", though it is closer. As for the "bent wing" you are making too big a deal out of this. Yes it is "bent" but only for about the first 4 feet or so are angled moderately down. It was found that because of prop effects this didn't hurt the lift that much and it was important to keep the landing gear short for such a big prop.






Notice that the span is measure horizontally, not along the wing surface. Still, this has nothing to do with the elevators. As you can clearly see...






the Corsair clearly has a lot more elevator area than the Spitfire.



Soren said:


> RG_Lunatic said:
> 
> 
> > Davidicus,
> ...



Umm... when the angle of attack is higher the nose points down. *To facilitate this you angle the prop/hub UP NOT DOWN!* On the F4U-5 the engine and prop were angled up an additional 2 degrees to better facilitate the nose down flight attitude to provide even more visiability over the its longer nose. The AOA of the Spitfire wing is almost exactly level with the fuelage line. The prop is angled down to support its very flat flight attidue, allowing the whole plane to be angled up to gain AoA for the wings. So the Spitfire tends to fly nose up (relatively speaking, the nose may still point down somewhat to counter wing lift during level flight), where the Corsair flies nose down.

=S=

Lunatic


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## Soren (Apr 25, 2005)

RG those drawings are OFF SCALE ! I will however agree that the Corsairs elevator area is bigger, but not by much.



> Umm... when the angle of attack is higher the nose points down. *To facilitate this you angle the prop/hub UP NOT DOWN!*



Oh really !  

RG, the AoA is higher when the wings are pointing UP, NOT DOWN ! So the Prop/Hub is tilted DOWN on the Spitfire to INCREASE the AoA of the wing thereby INCREASING the lift !

Lift will increase as the angle of attack is increased up to the point (usually around 17 degrees) where the aircraft stalls, the critical angle of attack. 



> On the F4U-5 the engine and prop were angled up an additional 2 degrees to better facilitate the nose down flight attitude to provide even more visiability over the its longer nose.



This upwards tilt of the nose and downwards tilt of the wing will reduce lift RG, and try to push the plane down, thus the lift is decreased even further yet ! (And actually Im sure you got it backwards with the Corsairs wings, as its wings were also AFAIK pointed slightly upwards)

About the "Bent" wing;

The bent sections of the Corsairs wings will produce very little lift, and those two section arent small RG, they make up approx. 7-8 sq.m of the Wing area ! Also the intakes on the leading edge in that area further reduces the lift ! 

Note: Alhtough the "Bent" sections of the Corsair wings will decrease lift, they will also reduce drag, making the Corsair go faster.


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## Anonymous (Apr 25, 2005)

Soren said:


> RG those drawings are OFF SCALE ! I will however agree that the Corsairs elevator area is bigger, but not by much.



The Corsair diagram is to scale. The drawing from which I cut it from gives all the dimensions and a ruler (as shown on the nose view). The Spit XIV diagram - well it was about the only one I could find - but by checking relative measurements for those dimesions I have data for it seems to be right too.



> Umm... when the angle of attack is higher the nose points down. *To facilitate this you angle the prop/hub UP NOT DOWN!*





Soren said:


> Oh really !
> 
> RG, the AoA is higher when the wings are pointing UP, NOT DOWN ! So the Prop/Hub is tilted DOWN on the Spitfire to INCREASE the AoA of the wing thereby INCREASING the lift !
> 
> ...



That's all fine Soren, but your not getting it. On the Corsair* both *the wings and the engine are tilted up. This makes the flight line such that when the plane is flying level (at the speed where lift and weight balance) the wings are level, the engine is pulling it strait ahead, and the nose is pointed down.

On the Spitfire the engine is pointed down, which means that when it is lined up on the level, the wings are pointed up, increasing the AoA. The whole plane must be canted up to get this added AoA.



Soren said:


> About the "Bent" wing;
> 
> The bent sections of the Corsairs wings will produce very little lift, and those two section arent small RG, they make up approx. 7-8 sq.m of the Wing area ! Also the intakes on the leading edge in that area further reduces the lift !
> 
> Note: Alhtough the "Bent" sections of the Corsair wings will decrease lift, they will also reduce drag, making the Corsair go faster.



The amount of lift lost by having the inner wing sections angled downwards will be exactly the projection of the vertical component of the normal vector to the wing, which is going to be a loss of only a couple of percent. I doubt there is any reduction in drag at all, since the drag does not care how the lift is being applied.


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## Soren (Apr 25, 2005)

> On the Spitfire the engine is pointed down, which means that when it is lined up on the level, the wings are pointed up, increasing the AoA. The whole plane must be canted up to get this added AoA.



RG only the Prop/Hub is pointing downwards on the Spit, while the wings are almost level with the fuselage, pointing upwards only very slightly. When in level-flight the Spit's Prop/Hub will be level, thus because of the Hub's tilt the wing's AoA is increased= More lift ! 



> The amount of lift lost by having the inner wing sections angled downwards will be exactly the projection of the vertical component of the normal vector to the wing, which is going to be a loss of only a couple of percent.



No RG, it is actually a quite substantial amount of lift that is lost by this ! 

A plane on its side in the air will also loose altitude, and is only descending slowly because of the G forces accuring in the slight turn being created by the lift of the wings.



> I doubt there is any reduction in drag at all, since the drag does not care how the lift is being applied.



About the Corsair's "Gull" wings: 
*The Corsair had a wing bent on both sides of the fuselage, or gull-shaped. This arrangement gave additional ground clearance for the propeller and reduced drag at the wing-to-fuselage joint.*


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## Anonymous (Apr 26, 2005)

Soren said:


> > On the Spitfire the engine is pointed down, which means that when it is lined up on the level, the wings are pointed up, increasing the AoA. The whole plane must be canted up to get this added AoA.
> 
> 
> 
> RG only the Prop/Hub is pointing downwards on the Spit, while the wings are almost level with the fuselage, pointing upwards only very slightly. When in level-flight the Spit's Prop/Hub will be level, thus because of the Hub's tilt the wing's AoA is increased= More lift !



That is exactly what I said. This makes the Spitfire fly in a nose up attidue.

However, the alternative solution is to cant the wings upwards relative to the fuselage, which was done on the F4U corsair (I believe 4 degrees added AoA over that of the prototype), and to cant the engine/prop up a little as well (though not as much). This gives the Corsair a significant nose down attitude when flying "level", which was done to the -1 series to give better visability over the nose when the cockpit was moved aft from the prototype design to facilitate the fuel being removed from the wings and the larger tank placed behind the engine and in front of the pilot. When the -5 came along, with its even longer nose, the thrust angle was raised another 2 degrees.



Soren said:


> > The amount of lift lost by having the inner wing sections angled downwards will be exactly the projection of the vertical component of the normal vector to the wing, which is going to be a loss of only a couple of percent.
> 
> 
> 
> No RG, it is actually a quite substantial amount of lift that is lost by this !



No there is not Soren. The lift lost follows the same rules of physics as anything else... I thought you knew your physics? You sure do refer to it a lot in your arguments for obviously not understanding it. Here's a diagram showing the cost in lift:






The blue vector represents the total force generated by the wing airfoil. The green vector represents the lift force provided in the upward direction. The red line segment represents the loss in lift as compared to an unbent wing. It's as simple as that. 



Soren said:


> A plane on its side in the air will also loose altitude, and is only descending slowly because of the G forces accuring in the slight turn being created by the lift of the wings.



The inner part of the wings are not angled down at anywhere near a 90 degree angle. And if they were the lifting force of the airfoil would be strait out to the side and thus the projection of the vertical component of the of the lift vector would be 0 thus no lift!



Soren said:


> > I doubt there is any reduction in drag at all, since the drag does not care how the lift is being applied.
> 
> 
> 
> ...



Why?


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## Soren (Apr 26, 2005)

> No there is not Soren. The lift lost follows the same rules of physics as anything else... I thought you knew your physics? You sure do refer to it a lot in your arguments for obviously not understanding it. Here's a diagram showing the cost in lift:



First off all I hope you'll soon see your mistake here ! Secondly STOP using different scale drawings all the time, and use those you have already used !!

Btw guess how much lift those intakes takes away with them !  



> The inner part of the wings are not angled down at anywhere near a 90 degree angle. And if they were the lifting force of the airfoil would be strait out to the side and thus the projection of the vertical component of the of the lift vector would be 0 thus no lift!



RG I NEVER implied the wings were angled anywhere near 90 degree's, I was just making a SIMPLE point wich you obviously didnt understand ! 




RG_Lunatic said:


> Soren said:
> 
> 
> > About the Corsair's "Gull" wings:
> ...



RG if you think real hard then you might find something that just doesnt add up.


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## Soren (Apr 26, 2005)

In the mean time here's how Vet pilot Owen W. Dykema saw the F4U-4 Corsair:

_In my career in Naval Aviation I flew a number of planes. Except for the twin-engine SNB "Bug Smasher", all were single-engine fighter / attack planes. The best and "funnest" was the Grumman F8F Bearcat. But I got the most flight time, and 47 combat missions off a carrier in Korea, in the Chance-Vought (C-V) F4U-4 Corsair. Its most noticeable characteristic was the inverted-gull wing.

The Corsair had a huge prop, 13 feet in diameter, necessary to absorb the 2200 horsepower of the big Pratt Whitney R-2800 radial engine. The cockpit was designed around the chief test pilot, Boone Guyton, who was 6-ft. 4-in. tall, so there was plenty of room in the cockpit, even for a 6-ft. 3-in.guy like me.

The Corsair was designed largely in the pre-war years, when design competitions tended to emphasize speed over maneuverability. C-V felt that if the wing joined the fuselage at a right angle the drag would be less, and the top speed would therefore be higher. It was that design goal of high speed that led to the long, narrow, cylindrical fuselage and the inverted-gull wing design. It did prove to be 50 knots or so faster than another plane using the same engine (the Grumman F6F Hellcat).

However, in 1939, when war began to threaten, the Navy came to C-V and asked for some modifications that would make the F4U more combat-ready as well. Among those were: (1) move the fuel out of its vulnerable position in wing tanks and put it up in the fuselage; and (2) increase the roll rate and at the same time lessen the stick forces required to roll the plane.

The first design change involved creating room in the fuselage for a 233-gallon fuel tank. To do that C-V pushed the engine forward a foot and the cockpit aft by three feet, and put that fuel tank right in front of the cockpit. That created an exceptionally long distance from the cockpit to the front of the engine, leading to nicknames for the plane like "hosenose" and "hog". As a further result, when the aircraft was in a three-point attitude, taxiing or flying at slow speeds (as in landing), everything in a rather broad angle ahead of the pilot was obscured. Eventually that created, at least for me, for a great deal of trouble landing aboard the carrier.

The second change involved lengthening and broadening the ailerons, which increased stick roll forces, and aerodynamically balancing those ailerons, which reduced those forces. A great deal of experiment and testing went into design of those ailerons. The final design was so heavily balanced that they were very nearly overbalanced. In the latter case the force of wind across the wing alone could cause the ailerons to move, thereby rolling the plane when least expected. One time that nasty characteristic nearly killed me.

The Corsair also had a few other unfortunate characteristics. Because of the high power of the engine and that big prop, there was a great deal of torque on the plane, particularly at slow speed and high power, as in a takeoff or in a waveoff from a carrier landing. A lot of inexperienced Ensigns and 2nd Lt.'s jammed the power on too fast and torque-rolled right into the ground. That led to the cynical "words to live by" (literally), "Low, slow and over you go in the F4U!".

In addition, it had very dangerous spin characteristics, particularly inverted. Especially in the Training Command lots of Ensigns and cadets spun right into the ground from thousands of feet up, unable either to stop the spin or to overcome the resulting high "g" forces to exit the aircraft, leading to the further nickname "Ensign Eliminator". This also led to the endless barracks argument, "In a spin in the Corsair, is it best to keep the power on full, to create strong airflow over the control surfaces, or to chop it off to get rid of the torque?" The only adequate answer always seemed to be, "Don't get into a spin in the Corsair."

In the cockpit the control stick stuck up between your legs and your legs stuck forward into twin "tunnels" that ended in the rudder pedals. On the control stick was a funnel-shaped device called a "pee-tube"(of obvious utilitarian function). On a left console (forward - aft) were the gear, flaps and arresting hook levers, the engine control unit, including throttle, prop (rpm) and mixture ratio controls, the trim tab control wheels and the wing fold controls. On the right console were the radios and circuit breakers. All such fighter and attack planes had to be flown "right-handed"._


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## Anonymous (Apr 26, 2005)

The salient part of this quote is:



> The Corsair was designed largely in the pre-war years, when design competitions tended to emphasize speed over maneuverability. C-V felt that if the wing joined the fuselage at a right angle the drag would be less, and the top speed would therefore be higher. It was that design goal of high speed that led to the long, narrow, cylindrical fuselage and the inverted-gull wing design. It did prove to be 50 knots or so faster than another plane using the same engine (the Grumman F6F Hellcat).



First off, the gulling of the wings was not done to increase speed, it was done to allow a large prop to be used while keeping the landing gear as short as possible. This was done to reduce weight while also maintaining the needed strength to land on a carrier.

Second, he implies the reason the F4U was faster than the F6F was because of the angle of the wings joining the body. While the angle of the wings being at 90 degrees might reduce drag very slightly it would not be by much. The angles were chosen very specifically to maximize the strength of the joint at the bend where the landing gear were.

And he further states that they had the same engine, which while technically correct is really wrong. The F6F used a much smaller single stage two speed supercharger, where the F4U used a much larger two stage two speed supercharger, giving the F4U much more power up where the air is thin and maximum speed could be higher.

Finally, the F6F was stubbier and fatter than the F4U, making for more drag and lower speed, and it was a little heavier too.

This is not much of a "source" Soren. Nothing in any of the technical papers I've read about the F4U's development refer to the angle of the wings having been done to reduce drag. If this is your only source for this information... well...

=S=

Lunatic


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## Soren (Apr 26, 2005)

RG_Lunatic said:


> This is not much of a "source" Soren. Nothing in any of the technical papers I've read about the F4U's development refer to the angle of the wings having been done to reduce drag. If this is your only source for this information... well...



It wasnt ment as a source RG, it was ment as a view-point ! I can't help that you immediately jump on the part with the decreased drag of the Gull wings, as it wasnt intended to proof this point. However as you just discovered it is obviously aparent that pilots also said it decreased drag, so there's a little extra something to think about.


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## Anonymous (Apr 27, 2005)

As we all know, pilots are very bad sources for engineering type information. They are known to quote false info all the time. Unless the pilot was a qualified engineer, it's probably hearsay many times removed from whatever the original source was, and totally mis related.


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## Anonymous (Apr 27, 2005)

Okay, I figured out how to get the airfoils into the windows software so I could provide a comparison graphic. Here there are:






As you can see, at the root the Corsair airfoil is thicker and has a sharper rise to the forward edge and its thicker, but it also is more symetrical from top to bottom, which probably makes it a little better at higher speeds and a little worse at lower speeds. The Spitfire wing has almost as much chord at the root as the Corsair wing.

At the the tip the most noticable difference is the relative chord - the Spitfire wing has become rather narrow. Techincally the measurement should be taken at 10% from the tip, however the difference was so extreme I decided to show them scaled against one another at 15% from the tip. To my eye, the tip shapes are very similar, with the Corsairs having its maximum thickness along the top a just a little further back (proprotionally) than that of the Spitfire, but on the bottom it is further back still.

Honestly I cannot tell which airfoil shapes are "better". I suspect they are very similar, with the Spitfire wing generating a little more lift at low speeds but a little more drag (proportionally) at higher speeds, especially near the roots. Next I'll have to figure out how to put these into airfoil simulation software and see if that shows any significant differences.

=S=

Lunatic


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## Gemhorse (Apr 27, 2005)

The gull-wing shape with inboard radiators on the leading-edge by the wing root would possibly offer less drag than the under-wing box radiators on the Spitfire, perhaps ???.........

Gemhorse


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## Soren (Apr 27, 2005)

RG_Lunatic said:


> Okay, I figured out how to get the airfoils into the windows software so I could provide a comparison graphic. Here there are:
> 
> 
> 
> ...



Very nice comparison RG ! (Seriusly !)

However your forgetting that the root profile of the Corsair's wing is the one wich is tilted and has those two intakes ! (Both factors decrease lift by a big margin !)


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## Anonymous (Apr 27, 2005)

Soren, the intakes do not reduce lift that much, they are at an inefficient part of the wing. The part of the wing near the root receives a boundary layer effect off the fuselage and a turbulent effect off the prop. If it had been a huge issue they'd have moved the cooler inlets to the nose or scooped them from under the wing (like the Spitfire) or fuselage. You seem to think that the Vought (and Yakovlev) engineers were stupid.

As for the loss of lift for the angle, I've shown you how much is lost and it's negligable - a few percent that's all.

On top of that, airfoil cross-sections are taken vertically anyway.

Both those factors reduce lift by a tiny margin over a very small area.

=S=

Lunatic


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## Soren (Apr 27, 2005)

> Soren, the intakes do not reduce lift that much, they are at an inefficient part of the wing. The part of the wing near the root receives a boundary layer effect off the fuselage and a turbulent effect off the prop.



No RG, infact the intakes take away alot of lift ! Look at my little modification of your comparison at the bottom of the page. A good amount of airpressure is lost on the wing hitting that leading edge area !



> If it had been a huge issue they'd have moved the cooler inlets to the nose or scooped them from under the wing (like the Spitfire) or fuselage.



No cause they were looking for less drag RG ! As a result the fuselage was shaped circular and the wing shaped bent and inverted.

From: Bent-winged Bird to Whistling Death
_-and the Vought team turned to an inverted gull wing for two reasons. First, the landing gear could be mounted at the low point or "knuckle" of the wing, thus reducing the length of the landing gear struts, while still providing ground clearance for the big propeller. Second, the wing joined the circular fuselage at nearly a right angle, reducing drag and eliminating the need for bulky fairings._



> You seem to think that the Vought (and Yakovlev) engineers were stupid.



No RG, but in those times alot of mistakes were made in aerodynamics, wich also should be obvious to anyone. 



> As for the loss of lift for the angle, I've shown you how much is lost and it's negligable - a few percent that's all.



I can see you still havent realized your mistake yet.


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## wmaxt (Apr 27, 2005)

The 90deg attachment of the wing had the benifit of eliminating the root fillet to reduce the drag at the attachment point. The drag from this point is created by the turbulence caused by dissimilar airflows meeting at that point and is greater at any other angle. If this drag/turbulance is to great it can effect the stabilizor/elevator as well as the speed of the aircraft.


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## Anonymous (Apr 28, 2005)

Soren said:


> > Soren, the intakes do not reduce lift that much, they are at an inefficient part of the wing. The part of the wing near the root receives a boundary layer effect off the fuselage and a turbulent effect off the prop.
> 
> 
> 
> No RG, infact the intakes take away alot of lift ! Look at my little modification of your comparison at the bottom of the page. A good amount of airpressure is lost on the wing hitting that leading edge area !



Your diagram shows the intake both too large and set too high on the wing. The following diagram is approximately accurate (I cut away the wing diagram and re-oriented it to position the inlet):






As you can see, the inlet is both smaller than the one you depicted (relative to the thickness of the wing) and more importantly it is located lower along the leading edge. The air has to go somewhere. Pressure in the scoop will cause some of the air approaching the front of the inlet to flow around the wing, giving back some of the lift. Air traveling through the wing also gets heated and then vented restoring a little bit of the lost lift.

Yes there is some loss of lift, but it is no where near as signficant as you are making it out to be. If it was, Vought had pleanty of opportunities to move the scoops in the -4, -5, or -7 variants - they did not.



Soren said:


> > You seem to think that the Vought (and Yakovlev) engineers were stupid.
> 
> 
> 
> No RG, but in those times alot of mistakes were made in aerodynamics, wich also should be obvious to anyone.



Even today this is considered one of the better places to locate scoops, it is just inconvienient for plumbing reasons. 



Soren said:


> > As for the loss of lift for the angle, I've shown you how much is lost and it's negligable - a few percent that's all.
> 
> 
> 
> I can see you still havent realized your mistake yet.



LOL - point it out to me.

Here's the loss of lift due to the angle of the wing (shown in red):






That's about 6.25%.

=S=

Lunatic


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## Soren (Apr 28, 2005)

RG,

Look at the pic below, now tell me, what happens to a plane flying like that ?


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## Anonymous (Apr 28, 2005)

Well, it is obvious, it wll slide to the right. But that does not mean it has no lift.

On the F4U there is an equal and opposite force created by the other wing, which is bent in the other direction.

The loss of lift from the wing angle is as I've shown. If you like, we can contact an expert to confirm it


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## Soren (Apr 28, 2005)

> Well, it is obvious, it wll slide to the right.



It will also descend slightly.



> But that does not mean it has no lift



Not at all, but the lift will decrease along with the increase in angle.



> The loss of lift from the wing angle is as I've shown. If you like, we can contact an expert to confirm it


 
RG do we agree that at 90* the wing has no upwards lift nomore ?

If so, then by tilting the plane 22.5-25* in either direction the "upwards lift" will be reduced by 25-27.2%. (This is what I seem to remember from Flight-school, although it was a long time ago )


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## Anonymous (Apr 29, 2005)

Ummm no.

Let me try to explain.

First I'm going to assert that the "lift" created by the wing passing through the air at a constant speed is perpendicular to the wing and does not change regaurdless of orientation. As long as the speed remains the same, the force in the direction of the top of the wing will remain the same. Furthermore, we will not consider the effect of changing angle of attack.

Furthermore, I'm going to define this force to be a unit vector with a strength of 1 Gravity. That is, we will assume that in level flight the total lift generated by the wing at the given constant speed is exactly sufficeint to counter the force of gravity. This is not necessary, but as you will see using 1 will make the math cleaner and easier to follow.

It is true that at 45 degrees the upward "lift" force equals the sideways "lift" force. However, *it is not equal to 1/2 the wings lifting force!*.

It is easier and more logical, at least for me, to work in radians. A radian is defined as the length of the radius of a circle meausured around its arc (i.e. in a curve). A circle is 2 x Pi radians in circumfrence. For a unit circle, a radian = 1 so that part drops out, and we can simply say a unit circle is 2 Pi in circumfrence.

So if a unit circle has a circumfrence of 2 Pi (radians). Half a circle has a of 1 Pi, a quarter circle (i.e. 90 degrees) is 1/2 Pi, an eight circle (45 degrees) is 1/4 Pi, and sixteenth circle (22.5 degrees) is 1/8 Pi.

Now, since we are working from the angle it is useful to use the sine and cosine (rather than derive them which would take a lot more text), which are defined as:

sine = In a right triangle, the ratio of the length of the side opposite an acute angle to the length of the hypotenuse. This is our sideways force vector.

cosine = In a right triangle, the ratio of the length of the side adjacent to an acute angle to the length of the hypotenuse. This is our upward force vector.

When the wing is angled at 45 degrees (1/4 Pi), down and to the left, the 1G lift vector will point up and to the left, and this unit vector forms the hypontenous of a right triangle, with the sides pointing horizontally to the left and vetically up.

sin(0.25 x Pi) = 0.707106781 {you can enter "sin (0.25 x Pi) =" into google and it will give you this result}

and (for this angle)

cos(0.25 x pi) = 0.707106781

So, as I hope you can see, at 45 degrees of bank the loss upward lift is only about 30%, not the 50% you thought.

You can confirm this by using the pythagorean theorim, which says that the squareroot of the sum of the squares of the sides of this triangle should equal 1.

Now, applying the same math to the angle of 22.5 degrees we can see that:

sin(0.125 x pi) = 0.382683432
cos(0.125 x pi) = 0.923879533

So for a bank angle of 22.5 degrees (1/8 Pi) the loss in upward lift is only about 8.6%.

=S=

Lunatic


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## Soren (Apr 29, 2005)

RG_Lunatic said:


> So for a bank angle of 22.5 degrees (1/8 Pi) the loss in upward lift is only about 8.6%.



No no no !! Its "_about 6.25%_"  

See your mistake ?


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## cheddar cheese (Apr 29, 2005)

Sine and cosine? I thought they were restricted to math


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## Anonymous (Apr 29, 2005)

Soren said:


> RG_Lunatic said:
> 
> 
> > So for a bank angle of 22.5 degrees (1/8 Pi) the loss in upward lift is only about 8.6%.
> ...



LOL - I did it off a graphic and used scaling to estimate the loss. If the angle of the wing is 22.5 degrees down, then the loss would be 8.6%, I am not sure what the actual angle was.

Anyway, I hope you see that your %'s for lift are based upon a linearity that is incorrect?


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## Soren (Apr 29, 2005)

At 45 degree's the loss of upward-lift is about 40% RG, *not 30%*, as it takes about 1.4G's to maintain constant height at a 45 degree bank angle(It takes 40% more lift to cancel out weight). At a 60 degree bank angle you need 2G's to maintain constant height. (Thats 100% more lift to cancel out weight)

This is how I was told it works atleast.


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## Anonymous (Apr 29, 2005)

Soren said:


> At 45 degree's the loss of upward-lift is about 40% RG, *not 30%*, as it takes about 1.4G's to maintain constant height at a 45 degree bank angle(It takes 40% more lift to cancel out weight). At a 60 degree bank angle you need 2G's to maintain constant height. (Thats 100% more lift to cancel out weight)
> 
> This is how I was told it works atleast.



LOL... do the math Soren....

0.707106781 x 1.4 = 0.989949493 = about ONE!

And....

cos(60 degrees) = 0.5, so 0.5 x 2.0 = ONE!

So you see, there is no conflict between what they taught you in flight school and the math I've shown you at all!

I hope this all becomes clear to you. I've had jobs where I've had to do complex vector and matrix algebra all day long, so I have an advantage here. I can see what the outcome of the math is going to be almost instantly without even doing it.

I hope you will look over the math and try to understand it. If you have any questions feel free to ask. This kind of math has many applications and once you "get it" it is actually very easy. This is why I went into radians a bit above even though I could have avoided doing so. If you work things out a bit in radians you will get the big picture much faster than working in "degrees".

=S=

Lunatic


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## Soren (Apr 30, 2005)

RG_Lunatic said:


> Soren said:
> 
> 
> > At 45 degree's the loss of upward-lift is about 40% RG, *not 30%*, as it takes about 1.4G's to maintain constant height at a 45 degree bank angle(It takes 40% more lift to cancel out weight). At a 60 degree bank angle you need 2G's to maintain constant height. (Thats 100% more lift to cancel out weight)
> ...



It is quite clear to me, however you said that at a 45 degree bank angle the loss of lift was about 30%, while it is actually 40%. I was just trying to make a simple correction, thats all.

Anyway the loss of lift is close to 9-10% on each wing, wich is more than what Wing-thickness can make up for, wich is the point. 

Perhaps since you downloaded this "Airfoil program" you could calculate the exact difference of lift when thickness is increased by 1-5% ? I will get the program myself as soon as I find out how to make it work on XP, as it seems it will only run on Win95. And at the cost of 179$, I would like to find out about that first.


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## Anonymous (Apr 30, 2005)

Soren said:


> RG_Lunatic said:
> 
> 
> > Soren said:
> ...



No Soren, it is not, it is about 30%. I just showed you this is the case. 

At 1 G of lifting force off the wing, angled at 45 degrees the upward lifting force will be 0.707106781 G. That is about a 29.3% lost lift, which for purposes of discussion is "about 30%".

The fact that it takes ~40% more lift (via speed) off the wing to achieve 1 G of upward lifting force simply reflects the fact that about 30% of that lift will be lost as well. To get an additional 30% more upward lift you need an about an additional 43% lift at the 45 degree angle.



Soren said:


> Anyway the loss of lift is close to 9-10% on each wing, wich is more than what Wing-thickness can make up for, wich is the point.



No, the loss of lift is about 30% of the total lift for the angled part of the wing, which extends about 4 feet from root to elbow on each wing. The wingspan is about 41 feet, 4 feet of which is taken up by the fuselage. So figuring the total wing span of about 35 feet, only about 22% of that is bent down. So the loss in lift compared to a level wing is about 0.22 x 30% = ~6.6%. The higher wing thickness applies to the whole wing, so it will make up for this loss of lift, and probably exceed it substantially.



Soren said:


> Perhaps since you downloaded this "Airfoil program" you could calculate the exact difference of lift when thickness is increased by 1-5% ? I will get the program myself as soon as I find out how to make it work on XP, as it seems it will only run on Win95. And at the cost of 179$, I would like to find out about that first.



The airfoil program I downloaded is a 45 day evaluation version of "TraCFoil", which allows you to display the airfoils, it does not allow any simulations. It was sufficient to capture the airfoil shapes for this thread.

FoilSim from NASA may be sufficient to analyze the lift of the airfoil shapes. What I have not found yet is anything (for free) which will allow the whole wing to be analyzed. Use of something like FoilSim will probably be sufficient given 5 or more cross-sections - but the problem here is we don't know how fast the root airfoil transitions to the tip airfoil. Thus I'm still researching this (I have a few emails outstanding with ?'s about this).

=S=

Lunatic


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## Jank (Apr 30, 2005)

Trying to keep up here. Wingspan of 41 feet. Fuselage takes up 4 feet. Each wing is 18.5 feet. 4 feet of each wing is ther downward root to elbow position that accounts for 22% of each wing suffering from the loss of lift of 30%.

Isn't that an overall lift loss of 9%?


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## Soren (Apr 30, 2005)

> No, the loss of lift is about 30% of the total lift for the angled part of the wing, which extends about 4 feet from root to elbow on each wing. The wingspan is about 41 feet, 4 feet of which is taken up by the fuselage. So figuring the total wing span of about 35 feet, only about 22% of that is bent down. So the loss in lift compared to a level wing is about 0.22 x 30% = ~6.6%. The higher wing thickness applies to the whole wing, so it will make up for this loss of lift, and probably exceed it substantially.



RG stop making one statement and then another ! You said the loss of lift would be about 8.6% for a 22.5 degree angle, and now your changing it to 30% ! Make up your mind !!

Also the wing thickness will not increase lift by any big margin, only by a very small one ! The Tempest and Typhoon comparison test is a good example of this without going into the exact aerodynamic numbers. Tests between the Hurricane and Spitfire also revealed that they both turned very equally, and eventhough the Hurri had both lower wing-loading and a much thicker airfoil the Hurricane still turned only very slightly better.



> The airfoil program I downloaded is a 45 day evaluation version of "TraCFoil", which allows you to display the airfoils, it does not allow any simulations. It was sufficient to capture the airfoil shapes for this thread.
> 
> FoilSim from NASA may be sufficient to analyze the lift of the airfoil shapes. What I have not found yet is anything (for free) which will allow the whole wing to be analyzed. Use of something like FoilSim will probably be sufficient given 5 or more cross-sections - but the problem here is we don't know how fast the root airfoil transitions to the tip airfoil. Thus I'm still researching this (I have a few emails outstanding with ?'s about this).



I am prepared to pay money for the program, but not before finding out if it will at all work on a PC with XP installed on it. So what I need is a 'Demo' of some sort.


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## Anonymous (Apr 30, 2005)

Jank said:


> Trying to keep up here. Wingspan of 41 feet. Fuselage takes up 4 feet. Each wing is 18.5 feet. 4 feet of each wing is ther downward root to elbow position that accounts for 22% of each wing suffering from the loss of lift of 30%.
> 
> Isn't that an overall lift loss of 9%?



Hmmm, the total wingspan is 41 feet. The fuselage eats up about 4 feet (at the level of the wing join) leaving 37 feet. The bent part is 8 feet of 37 feet,

8/37 = 0.216216216 = ~22%

0.22 x 0.30 = 0.066

I don't see where you come up with 9% Jank????

=S=

Lunatic


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## Anonymous (Apr 30, 2005)

Soren said:


> > No, the loss of lift is about 30% of the total lift for the angled part of the wing, which extends about 4 feet from root to elbow on each wing. The wingspan is about 41 feet, 4 feet of which is taken up by the fuselage. So figuring the total wing span of about 35 feet, only about 22% of that is bent down. So the loss in lift compared to a level wing is about 0.22 x 30% = ~6.6%. The higher wing thickness applies to the whole wing, so it will make up for this loss of lift, and probably exceed it substantially.
> 
> 
> 
> RG stop making one statement and then another ! You said the loss of lift would be about 8.6% for a 22.5 degree angle, and now your changing it to 30% ! Make up your mind !!



Oops I goofed you are right! Thank you for catching my error! I applied the 30% loss figure, when in fact it should be only 8.6%.

So the lost lift should be 0.22 x 0.086 = ~1.9%! Barely any loss at all!



Soren said:


> Also the wing thickness will not increase lift by any big margin, only by a very small one ! The Tempest and Typhoon comparison test is a good example of this without going into the exact aerodynamic numbers. Tests between the Hurricane and Spitfire also revealed that they both turned very equally, and eventhough the Hurri had both lower wing-loading and a much thicker airfoil the Hurricane still turned only very slightly better.



The Tempest and Typhoon are not a good comparison because the Tempest is a little lighter which should make it turn better but has a thinner laminar flow type airfoil which should make it turn worse. Reports I've read indicate the Typhoon turned noticably better than the Tempest. As for the Hurc vs. the Spitfire, there are too many other variables involved to make much of a comparison.



Soren said:


> I am prepared to pay money for the program, but not before finding out if it will at all work on a PC with XP installed on it. So what I need is a 'Demo' of some sort.



Well, it would be interesting to see the results. However, I think it is foolish to spend the kind of money you will need to spend on a quality program unless you plan to build planes (or model planes). But of course that's your call 8)

=S=

Lunatic


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## Soren (Apr 30, 2005)

> Oops I goofed you are right! Thank you for catching my error! I applied the 30% loss figure, when in fact it should be only 8.6%.
> 
> So the lost lift should be 0.22 x 0.086 = ~1.9%! Barely any loss at all!



No problem.

The loss of lift on the bent sections is 8.6%, but the outer wings are also bent slightly at approx.10 degree's leaving almost no loss there though.



> The Tempest and Typhoon are not a good comparison because the Tempest is a little lighter which should make it turn better but has a thinner laminar flow type airfoil which should make it turn worse.



RG the Tempest was only lighter by a mere 380lbs, not enough to make any difference at all.  However the thing that did make a difference was the Laminar airfoil !



> Reports I've read indicate the Typhoon turned noticably better than the Tempest.



RG im going to have to need a sourcee on that, as all my available sources state the Typhoon and Tempest to be VERY equal in turning circles.



> As for the Hurc vs. the Spitfire, there are too many other variables involved to make much of a comparison.



Variables like what ?



> Well, it would be interesting to see the results. However, I think it is foolish to spend the kind of money you will need to spend on a quality program unless you plan to build planes (or model planes). But of course that's your call 8)



Im not low on finances , and the program will be of very good use to me as a matter of fact ! 8) 

Just need to figure out how to get the damn thing to work on XP !


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## Anonymous (Apr 30, 2005)

Soren said:


> > Oops I goofed you are right! Thank you for catching my error! I applied the 30% loss figure, when in fact it should be only 8.6%.
> >
> > So the lost lift should be 0.22 x 0.086 = ~1.9%! Barely any loss at all!
> 
> ...



Yes, 8.6% for the ~22% of the total wing that is bent down, for a total loss of lift across the whole wing of about 1.9%.

The remaining part of the wing is bent up at 6.5 degrees, causing a whopping 0.64% loss, which I think we can agree is insigificant.



Soren said:


> > The Tempest and Typhoon are not a good comparison because the Tempest is a little lighter which should make it turn better but has a thinner laminar flow type airfoil which should make it turn worse.
> 
> 
> 
> ...



Generally the Typhoon suffered from "winding up" in a turn and very heavy elevator response, which diminished its turn quality, so it makes this comparision against the Tempest kind of mute. It was not the wings that made the two planes almost identical in evaluated turn quality.



Soren said:


> > As for the Hurc vs. the Spitfire, there are too many other variables involved to make much of a comparison.
> 
> 
> 
> Variables like what ?



Control surface composition, size, and actuation. Engine power (depends on model), etc... In the early models with fabric coverings on both, the Hurc was noticably more nimble.



Soren said:


> > Well, it would be interesting to see the results. However, I think it is foolish to spend the kind of money you will need to spend on a quality program unless you plan to build planes (or model planes). But of course that's your call 8)
> 
> 
> 
> ...



Well, as long as you have a use for it beyond these discussions  

If you can tell me exactly what you want out of such a program I might be able to help you find one. I've run through a lot of them over the last few weeks. Do you plan to build wings? If so, would these be for scale model aircraft with wood ribs/struts/spars? There is software specifically for models which differs from that for real aircraft.

=S=

Lunatic


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## Soren (Apr 30, 2005)

> Yes, 8.6% for the ~22% of the total wing that is bent down, for a total loss of lift across the whole wing of about 1.9%.
> 
> The remaining part of the wing is bent up at 6.5 degrees, causing a whopping 0.64% loss, which I think we can agree is insigificant.



Agreed.



> Generally the Typhoon suffered from "winding up" in a turn and very heavy elevator response, which diminished its turn quality, so it makes this comparision against the Tempest kind of mute. It was not the wings that made the two planes almost identical in evaluated turn quality.



Well IIRC the Tempest had a 4mph lower stall speed  I guess the Aspect ratio of the Tempest's wing was what made it equal to a Typhoon in a turn. 



> Control surface composition, size, and actuation. Engine power (depends on model), etc... In the early models with fabric coverings on both, the Hurc was noticably more nimble.



The Hurri was never more nimble than the Spit, however it turned slightly better in the early stages, but as soon as the fabric coverings got extinct this all changed.



> Well, as long as you have a use for it beyond these discussions



Indeed I have  



> If you can tell me exactly what you want out of such a program I might be able to help you find one. I've run through a lot of them over the last few weeks. Do you plan to build wings? If so, would these be for scale model aircraft with wood ribs/struts/spars? There is software specifically for models which differs from that for real aircraft.



Well I was planning to maby use it for 1:20-25 scale "flying" aircraft models, but I like the Idea of having all the info on full scale airfoils aswell. 

I tried to download this Foilsim program but it doesnt seem to work, even after downloading all the updates required. So im suspecting it doesnt work on XP.


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## Anonymous (Apr 30, 2005)

FoilSim works, but you may need to update your Java to enable it, and it may be blocked by your browser security. However, it's kinda primative and only useful for very general stuff. It's intended for school kids to use to get some feel for this topic.

The thing is the model airplane airfoil programs help you to put wooden ribs/struts/spars where needed, the real plane programs use a different dynamic for this. So I'm not sure you are going to find one program that does both. I'll look for some of both kinds so you can choose.

=S=

Lunatic


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## Jank (Apr 30, 2005)

If 22% of each wing has got got inly 70% lift, then the totasl loss over the entire wing is 9%.

each wing is 18.5 feet. 11.43 feet of which are developing 100% lift. 4.07 feet of which are developing only 70% lift. (30% less)

With 11.43 feet developing 100% lift and 4.07 feet developing 70% lift therre is 9% less lift than if the entire 18.5 feet developd 100% lift.


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## Soren (Apr 30, 2005)

> The thing is the model airplane airfoil programs help you to put wooden ribs/struts/spars where needed, the real plane programs use a different dynamic for this. So I'm not sure you are going to find one program that does both. I'll look for some of both kinds so you can choose.




Thanks RG, I appriciate it.


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## Anonymous (May 1, 2005)

Jank said:


> If 22% of each wing has got got inly 70% lift, then the totasl loss over the entire wing is 9%.
> 
> each wing is 18.5 feet. 11.43 feet of which are developing 100% lift. 4.07 feet of which are developing only 70% lift. (30% less)
> 
> With 11.43 feet developing 100% lift and 4.07 feet developing 70% lift therre is 9% less lift than if the entire 18.5 feet developd 100% lift.



Each wing is about 18.5 feet, 14.5 feet of which is developing about 98.1% lift and 4 feet of which is devloping about 91.4% (I erroneously used 70% in my earlier post - you must have missed where Soren corrected me!).

The problem in your math is that 11.43 + 4.07 = 15.5, not 18.5. Somewhere you lost 3 feet off each wing!

=S=

Lunatic


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## Anonymous (May 1, 2005)

Soren,

I've checked out some aifoil/windtunnel simulation software. What I can find with demo's that run under $300 seems pretty crappy so far.

It appears the good stuff is in the $600-$1000 range.

The following seems the most complete package... with the most complete price too:

http://www.hanleyinnovations.com/airfoils.html

They have a "lite" version for $295, but it only does NACA airfoils:

http://www.hanleyinnovations.com/vfnaca.html

The demo at http://www.hanleyinnovations.com/vfdemo.html gives an idea of how the program works and what it can do.

I'll keep looking.

I am pretty sure all of these programs should run under WinXP.

=S=

Lunatic


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## Anonymous (May 1, 2005)

This program seems very useful - though it is hard to evaluate the unregistered version as you cannot load up your choice of airfoils. However, registration is only $10!

http://www.profili2.com/eng/default.htm

=S=

Lunatic


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## Soren (May 1, 2005)

Thank you very much RG. 

Im not sure yet, but I think its going to be the "NACA Visualfoil program" for 264$ to begin with, and that last one looks good for my modelling project. 

Once again thanks for taking the time to find these, I appriciate it !


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## Anonymous (May 1, 2005)

You're welcome - but... I'm not done yet Soren.

I have a list of things to research (typically about 1/3rd are for this forum). I put an hour, sometimes two into it most days. I don't usually allow myself any more time than that or I get nothing else done. I bumped this to the top of the list today since we both have an interest in this stuff. I'm sure it will come to the top again in the next day or two. However, usually about 90% of the good finds come in the first hour or so of searching - in this case a little more because I had to install a bunch of demos and rule out some (like "Design Foil" which just has a bad interface).

Anyway, please wait at least a week to plunk down the cash, as I might find something better. Also, give ProFili2 a good look, it's only $10 to register it, and then a snailmail delay to get the release code. It looks pretty damn decent for $10.

=S=

Lunatic


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

but mightn't there be other charges??


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## Anonymous (May 2, 2005)

the lancaster kicks ass said:


> but mightn't there be other charges??



I just got back an email, pricing has changed slightly:

The basic ProFili2 version is 10 EU ($13 USD), the pro version is 40 EU ($50 USD), and there is another associated program called IsPlot (not sure what it does) which is 10 EU ($13 USD).

Beyond that there seems to be no other charges.

=S=

Lunatic


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## Soren (May 2, 2005)

RG_Lunatic said:


> You're welcome - but... I'm not done yet Soren.
> 
> I have a list of things to research (typically about 1/3rd are for this forum). I put an hour, sometimes two into it most days. I don't usually allow myself any more time than that or I get nothing else done. I bumped this to the top of the list today since we both have an interest in this stuff. I'm sure it will come to the top again in the next day or two. However, usually about 90% of the good finds come in the first hour or so of searching - in this case a little more because I had to install a bunch of demos and rule out some (like "Design Foil" which just has a bad interface).
> 
> ...



Thank you RG.

I'll check out the program sometime in this week, or the next, as Im a little busy in this weeks. But I'll wait for your search results before buying anything.

Thank you for taking the time to find these, I hardly ever have time for it myself so its great help.


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## mike siggins (Apr 11, 2013)

50 cal shell are devastiting i ve seen them in action


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## GregP (Apr 12, 2013)

Pages and pages of math. 

The vertical component of lift at 22.5° is 92.387%, so the loss is 7.621% ... (92.387 + 7.613 = 100). The vertical component at 45° is 70.711%, so the loss of 29.289%.

The vertical component of lift is the (total lift multiplied by the cosine of the bank angle), the loss is (the total lift multiplied by 1 - the cosine of the bank angle), and the g-load factor is (1/cosine of the bank angle). The horizontal component of the lift is the (total lift multiplied by the sine of the bank angle).

All done with lift math and moving to another thread ... good luck guys. 

Wait ... I see the math was back in 2005 ... 

Never mind ... forget it.

50-cal shells will take an empty 55-gallon barrel and tumble it 30 - 50 feet when they hit ... and that's with 1 hit. I've done it when I was in the Army. There was a single-shot 50-cal spotting rifle above the barrel of the so-called M40 106 mm recoiless rifle (really a 105 mm, but they used the 106 name to reduce confusion with the failed M27 105mm unit). The 50 hits pretty darned hard for a fact.

Not too good against armor, but anything unarmored (like an airplane) is badly damaged. It will absolutey clean the decks of an armored cruiser or any other ship ... but you might also get shot down doing it by the cruiser's defensive weapons.


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