Allied Gold-Match

[FLYBOYJ]

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

 

[Nonskimmer]

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.

 

[Soren]

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.

 

[DAVIDICUS]

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.

 

[Soren]

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 ?

 

[Soren]

. 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.

 

[DAVIDICUS]

"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?

 

[Soren]

"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.

 

[DAVIDICUS]

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.

 

[Soren]

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.

 

[Anonymous]

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.

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.

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, 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.

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.

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.

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

 

[Anonymous]

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]

 

[Anonymous]

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.

 

[Anonymous]

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.

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.

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.

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.

 

[Soren]

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]

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]

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]

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]

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

 

[Anonymous]

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 ?

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.

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.

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 !

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.

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 !!

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

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.

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).

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

I think you missed something ! :

F4U-4 Max speed: 446 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