# F4U Corsair



## nimrod.michaeli (Apr 28, 2009)

why did the corsair had bended wings


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## michaelmaltby (Apr 28, 2009)

It had gull wings for clearance to raise the propeller off the landing surface. The P-47 had telescoping struts to achieve the same end.


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## MikeGazdik (Apr 29, 2009)

Exactly. They wanted the gear to be shorter and thus stronger for the harsh carrier landings.

I have also read that a 90 deg attachment of the wing to the fuselage was an aerodynamic advantage, and because the wing "bent" up to join the fuselage this 90 deg. theory was realized. I'm not sure if that was intended by Vought, more than an accidental and fortunate result.


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## Doughboy (Apr 29, 2009)

It also boosted the speed.


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## davebender (Apr 29, 2009)

The bent wing contributed to the F4Us hefty price tag. A not so fortunate result. But if you're willing to pay the price then the F4U was a very capable aircraft.

Suppose the U.S. Army Air Corps had adopted a F4U variant to replace the P-39 and P-40 for medium and low altitude missions. Would they produce it with a different wing? How much money would this save?


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## Marshall_Stack (Apr 29, 2009)

davebender said:


> The bent wing contributed to the F4Us hefty price tag. A not so fortunate result. But if you're willing to pay the price then the F4U was a very capable aircraft.



The USN could purchase 5 Hellcats for the same price as 3 Corsairs.

Didn't the Corsair also have a bigger prop than the P-47?


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## Colin1 (Apr 29, 2009)

Marshall_Stack said:


> Didn't the Corsair also have a bigger prop than the P-47?


I believe it did
but not sensationally bigger
The later P-47 hydromatic screw had a diameter of 13' 2"; I believe the F4U was either 13' 4" or 13' 6", I'll have a look when I get home. Jug drivers had to be careful they had the ground clearance before bringing the tail up and similar care on landing, owing to something like a measly 6" ground clearance for the screw.
Again, I don't know what the F4U's was but if it was similar it must have been fun trying to bring that down on a carrier without bending anything. 
I agree with the earlier comment, I think the bent-wing config was more about strengthening the undercart than getting the prop up in the air although it would certainly have helped.


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## tomo pauk (Apr 29, 2009)

Doughboy said:


> It also boosted the speed.



Any good info about that?


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## Doughboy (Apr 29, 2009)

Here is where I found it. Vought F4U Corsair - USA

And here is the paragraph."Since the landing gear had to be very strong to withstand the pounding of a carrier deck landing, a short, stout leg was required. Also, there wouldn’t be enough room in the wing to properly stow a longer gear. And, if the prop were shortened, much of the horsepower of the Double Wasp would be wasted. So, Vought engineers came up with the distinctive inverted gull-wing design which forever characterized the F4U Corsair. This "bent wing" design allowed the huge prop to clear the deck while providing for a short, stout landing gear. And, as a byproduct, the wing also improved the aerodynamics of the intersection where the wing attaches to the fuselage, boosting the top speed".


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## Colin1 (Apr 29, 2009)

I don't see how a bent-wing config decreases the frontal area drag coefficient and those leading edge-integrated intakes weren't all gain, I believe some or even most of them were quite 'dirty' but I'm sure Bill (drgondog) can clear that one up.


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## Catch22 (Apr 29, 2009)

It wasn't the frontal area that helped drag, it was the fact the wing came out of the fuselage at a 90 degree angle. It got rid of the need for a wing root cover, if that's the right terminology.


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## Colin1 (Apr 29, 2009)

Catch22 said:


> ...it was the fact the wing came out of the fuselage at a 90 degree angle. It got rid of the need for a wing root cover, if that's the right terminology.


Absence of wing-root fairing sounds plausible - 90 degrees to what though?


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## Waynos (Apr 29, 2009)

To the fuselage side I would imagine, on a circular section such as the F4U anything fixed perpendular that is attatched below half way will point downwards at an increasing angle the further down you go


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## Catch22 (Apr 29, 2009)

Colin1 said:


> Absence of wing-root fairing sounds plausible - 90 degrees to what though?



I'm not an aerodynamics guy, that is simply something I've read.


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## Catch22 (Apr 29, 2009)

Nevermind this, posted before I was done for some reason...


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## Catch22 (Apr 29, 2009)

Now that I'm on my computer and not my iPod, I can actually write a decent response.

When I read it, it struck me as odd as well. The thing is, I've read it in a couple different places, such as one of the Kagero F4U books and I'm fairly certain Corsair in Action. The lack of wing-root fairing (thanks for the right terminology! ) certainly makes sense, but I don't understand the angle part. Looking at models of it that I have around the house, the angle IS unique. It may not have been 90 degrees and I may have mis-remembered, but try comparing it to the Hellcat. It's really hard to explain, but the Corsair's nose area is almost, if not perfectly, round, so wherever the wing comes out of it's at the top arc of the curve. If you look at the Hellcat, which is oval, and where the wing comes straight out of the plane, the bottom of the wing is longer than the top, whereas the Corsair's are equal, if that makes any sense. Basically if you took the Corsair's wing off at the root where it comes out, and placed a ruler along the edge of the top and the edge of the bottom so it was going up and down, it would be straight up on its end. If you did the same for the Hellcat, however, it would be at a diagonal, slanted out towards the wingtip. I hope that makes sense. Now, don't ask me what that has to do with aerodynamics, I'll leave that to you guys to figure out!


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## Graeme (Apr 30, 2009)

MikeGazdik said:


> They wanted the gear to be shorter and thus stronger for the harsh carrier landings.



Off topic, but does anyone know the length of Vought's Cutlass nose wheel leg?


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## A4K (Apr 30, 2009)

Interesting info guys! I lamely thought it was to enable it's use as a dive bomber aswell (look at the Stuka), but there you go...


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## davparlr (Apr 30, 2009)

Graeme said:


> Off topic, but does anyone know the length of Vought's Cutlass nose wheel leg?



No, but I think it was noted for weakness and had a reputation for killing pilots when it collapsed.


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## Colin1 (Apr 30, 2009)

davparlr said:


> No, but I think it was noted for weakness and had a reputation for killing pilots when it collapsed.


If that's a standard workbench to the right with the toolbox on top and that's a normal engine crane to the left, that leg's got to be touching 7ft


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## Doughboy (Apr 30, 2009)

davparlr said:


> No, but I think it was noted for weakness and had a reputation for killing pilots when it collapsed.


The marines mostly used the Corsair, because the landing gear would snap off while landing on a carrier.


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## Catch22 (Apr 30, 2009)

Doughboy said:


> The marines mostly used the Corsair, because the landing gear would snap off while landing on a carrier.



No, that's not it at all. The landing gear had too much bounce that wasn't solved until later on into the war, and they would bounce all over the deck when landed.


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## michaelmaltby (Apr 30, 2009)

The Royal Navy operated Corsairs at sea successfully - by reducing the inflation pressure on the oleo struts sufficiently to reduce bounce.

Back to the pros-cons of Gull Wings - Corsair wings are inverted Gull for the various reasons described at the top of this thread. Non inverted Gull wings were used on aircraft like German flying boats to raise the engines props higher from the water. In both cases, clearance and strength seem to be the number one factor in the design.

MM


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## Doughboy (Apr 30, 2009)

Catch22 said:


> No, that's not it at all. The landing gear had too much bounce that wasn't solved until later on into the war, and they would bounce all over the deck when landed.


Okay...That makes sense.


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## Ivan1GFP (Apr 30, 2009)

Hello Folks,

I believe the claimed advantage of the inverted gull wing on the Corsair was that the join between the wing and fuselage was the smallest area that it could be because the joint was at a 90 degree angle. I believe that the lack of a need for a fillet was incorrect. Observe that the heavily modified Corsairs that are currently used in Unlimited Class air racing DO have fillets at the wing root.

There is no question that the landing gear struts could be shorter with the inverted gull wing. Because of the design, the length of the strut and wheel was limited by wing chord.

I believe the other aerodynamic issues are the following:
The Corsair has very low lateral stability because the center of lift is VERY low in relation to the center of gravity.
The wing center section is a major contributor to lift because the wing bends act as fences to prevent the high pressure air from spilling out to the wingtips. Modern jet fighters use the center fuselage section between widely spaced engines for the same effect.

Let me know what you all think.
- Ivan.


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## Colin1 (Apr 30, 2009)

Ivan1GFP said:


> ...the join between the wing and fuselage was the smallest area that it could be because the joint was at a 90 degree angle


Hi Ivan
I know I'm being a bit slow here
so if I drew an imaginary line back through the bent section of the wing (looking at the a/c from head-on) and continued the line back into the cylindrical fuselage, it would - in 2D - pass through the centre of the circle created by the frontal aspect of the fuselage (the longeron datum line)?

I'm trying to get a fix on what this wing angle is at 90 degrees to, mating as it does to a cylindrical (fuselage) section.


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## Ivan1GFP (Apr 30, 2009)

Hi Colin1,
The wing root meets the fuselage at 90 degrees to the surface of the fuselage (surface of your cylinder). Consider that in most low wing monoplanes, the wing meets the fuselage almost at a tangent to the surface of the fuselage (cylinder). (The lower wing surface typically IS tangent to fuselage.) Because it meets at nearly a tangent, the intersection between wing root and fuselage is very large.

I am not an aerodynamics person. I just read a fair amount, so I don't know my opinions have a whole lot of validity.

- Ivan.


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## Colin1 (Apr 30, 2009)

Ivan1GFP said:


> I am not an aerodynamics person. I just read a fair amount, so I don't know if my opinions have a whole lot of validity


lol me neither but best I've heard so far


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## Catch22 (Apr 30, 2009)

Ivan1GFP said:


> Hi Colin1,
> The wing root meets the fuselage at 90 degrees to the surface of the fuselage (surface of your cylinder). Consider that in most low wing monoplanes, the wing meets the fuselage almost at a tangent to the surface of the fuselage (cylinder). (The lower wing surface typically IS tangent to fuselage.) Because it meets at nearly a tangent, the intersection between wing root and fuselage is very large.
> 
> I am not an aerodynamics person. I just read a fair amount, so I don't know my opinions have a whole lot of validity.
> ...



That's what I was trying to say, but you put it in much better words than I. I didn't do so hot in trig...


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## MikeGazdik (May 1, 2009)

As far as the wing to fuselage goes, it is like a mid mounted wing. Like the F4f Wildcat. But a mid mount would create extremely long landing gear if it extends from the wing rather than the fuselage like a Wildcat. So you rotate the wing down to the "bottom" of the fuselage while still keeping a 90 deg. connection, and then bend the wing up towards an area around the lower or mid point of the fuselage.

I am no aerodynamcist myself, but I can easily see that this makes for a far less area of wing attachment to the body of the airplane.

And once again, I am not sure this was on purpose, but incidental. I think Vought first did this to simply shorten and strenghten the landing gear. 

If you look at a few threads back, I had a question about the aerodynamics of the Corsair. Drgondog and several others also contributed greatly to that question. The Corsair seems to be a study in questionable or unique aerodynamics. Starting at the wing and ending at the tail design. Truely a very unique fighter no doubt!

I read once, that anytime you see cranked wings, or twisted tails, you are seeing aerodynamic "fixes" for a less than perfect design. This was talking about the F4 Phantom jet fighter, but it may also apply in this instance.

And I am not slamming the F4U Corsair, I like them!


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## Graeme (May 1, 2009)

Colin1 said:


> Hi Ivan
> so if I drew an imaginary line back through the bent section of the wing (looking at the a/c from head-on) and continued the line back into the cylindrical fuselage, it would - in 2D - pass through the centre of the circle created by the frontal aspect of the fuselage (the longeron datum line)?



That's how I understand it Colin...


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## Graeme (May 1, 2009)

Based on Vought's V-326 (above) they trialled a R-4360 Wasp Major in a Corsair which became the* F4U-1 WM*, the predecessor to the F2G, but I don't know what year it was. No prop clearance problems here... 





...and there was an Aero Products contraprop trialled on a Corsair, but I don't know the diameter or when they did it...


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## Graeme (May 1, 2009)

Colin1 said:


> If that's a standard workbench to the right with the toolbox on top and that's a normal engine crane to the left, that leg's got to be touching 7ft



Excellent logic! Thanks Colin. I'd figure around the same, based on halving the "extended" dimension of this drawing. Either way it's a very long leg for a carrier plane. The Pirate and Cutlass didn't work out well for Vought.





Maybe the F-7D would have been the solution... 





Sought-After Models... [Archive] - The Great Planes and warbirds Community


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## tomo pauk (May 1, 2009)

Looks like a baby F-14


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## Catch22 (May 1, 2009)

MikeGazdik said:


> As far as the wing to fuselage goes, it is like a mid mounted wing. Like the F4f Wildcat. But a mid mount would create extremely long landing gear if it extends from the wing rather than the fuselage like a Wildcat. So you rotate the wing down to the "bottom" of the fuselage while still keeping a 90 deg. connection, and then bend the wing up towards an area around the lower or mid point of the fuselage.
> 
> I am no aerodynamcist myself, but I can easily see that this makes for a far less area of wing attachment to the body of the airplane.
> 
> ...



The thing about the F4U's crank though was that it was basically designed in from the get-go, it wasn't put in as a fix.


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## Ivan1GFP (May 1, 2009)

Way back someone was discussing the propeller diameter. The Corsair came with two different diameter 3 blade props. The first was 13'4" diameter. Its tips would go supersonic at full rpm and in fact was slower at full throttle than at part throttle (as tested by the British). The later prop was 13'2" and generally was better for performance. Regarding the contra-prop, the issue with it was that it added several hundred pounds to the weight of the aircraft and actually decreased performance over the 4 blade prop.

I believe that most aircraft need some kinds of refinement between prototype and production versions. F-104's anhedral, Fin fillet on the TBF Avenger, etc. It doesn't necessarily indicate that the basic design was faulty (though I do believe the F-104's basic design wasn't very good).

- Ivan the opinionated.


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## claidemore (May 2, 2009)

I'm curious to know what aerodynamic benifits were realized from the 90 degree wing/fuselage mounting on the Corsair? The F4F Wildcat (mid-wing, also 90 degree?) wasn't known as a speed demon, so I'm guessing speed increase wasn't it? 

I do see lots of daylight between the "v" of the gull wing and the horizontal stabilizer (in the image Graeme posted), and that should be a good thing as far as elevator control and stability I would think.


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## MikeGazdik (May 5, 2009)

claidemore said:


> I'm curious to know what aerodynamic benifits were realized from the 90 degree wing/fuselage mounting on the Corsair? The F4F Wildcat (mid-wing, also 90 degree?) wasn't known as a speed demon, so I'm guessing speed increase wasn't it?
> .



Or.. how much slower would it have been with a low mounted wing?


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## renrich (May 5, 2009)

There is no question that the intersection of the Corsair wing root with the fuselage was cleaner than the intersection of the wing and fuselage of the Hellcat with the fairing that was needed. That was a part of the reason that the Corsair had better performance than the Hellcat with essentially the same engine. The design philosophy of the Corsair was to have the smallest and cleanest air frame possible married to the most powerful radial engine available. The R2800 was chosen not only because of it's power but because it was a twin row engine which gave it a relatively small cross section and the fuselage of the Corsair was round like the engine and therefore had a small cross section. The wing intersection was a side effect of the effort to make the landing gear shorter and therefore stronger. It was fortunate that the amount of propellor clearance created was generous because the later Corsairs needed a taller tail wheel strut for aerodynamic and visibility effects. The prototype Corsair had all fuel in the wings and the guns in the nose. The desire to relocate the guns into the wings and most of the fuel into the fuselage and keep the fuselage slender resulted in moving the cockpit aft about three feet in order to create room for the fuselage fuel tank in production models. The moving of the cockpit created visibility problems, especially at high AOAs. The Corsair, as with all AC, was a series of compromises. The resulting AC, considering it's time frame, was an engineering tour de force.


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## Timppa (May 5, 2009)

I once calculated Cd's of various WW2 radial engined fighters. I was expecting fighters like the La-7 and Fw190A having the lowest figures. But F4U-1 came on top.


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## MikeGazdik (May 5, 2009)

I would LOVE to see those figures!! That had to be alot of work.


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## operator18 (Feb 2, 2010)

Colin1 said:


> Hi Ivan
> I know I'm being a bit slow here
> so if I drew an imaginary line back through the bent section of the wing (looking at the a/c from head-on) and continued the line back into the cylindrical fuselage, it would - in 2D - pass through the centre of the circle created by the frontal aspect of the fuselage (the longeron datum line)?
> 
> I'm trying to get a fix on what this wing angle is at 90 degrees to, mating as it does to a cylindrical (fuselage) section.



Don't fell bad. I've spent some time around a f4u-4b and I don't know what it is 90 degrees to either. The cross section is not round for the entire length of the cord.


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## operator18 (Feb 2, 2010)

renrich said:


> There is no question that the intersection of the Corsair wing root with the fuselage was cleaner than the intersection of the wing and fuselage of the Hellcat with the fairing that was needed. That was a part of the reason that the Corsair had better performance than the Hellcat with essentially the same engine. The design philosophy of the Corsair was to have the smallest and cleanest air frame possible married to the most powerful radial engine available. The R2800 was chosen not only because of it's power but because it was a twin row engine which gave it a relatively small cross section and the fuselage of the Corsair was round like the engine and therefore had a small cross section. The wing intersection was a side effect of the effort to make the landing gear shorter and therefore stronger. It was fortunate that the amount of propellor clearance created was generous because the later Corsairs needed a taller tail wheel strut for aerodynamic and visibility effects. The prototype Corsair had all fuel in the wings and the guns in the nose. The desire to relocate the guns into the wings and most of the fuel into the fuselage and keep the fuselage slender resulted in moving the cockpit aft about three feet in order to create room for the fuselage fuel tank in production models. The moving of the cockpit created visibility problems, especially at high AOAs. The Corsair, as with all AC, was a series of compromises. The resulting AC, considering it's time frame, was an engineering tour de force.


Actually the cockpit was moved back for cg considerations. The bent wing affords a better view of the ground than say an f6f. This was an advantage as a ground support aircraft. The issue was the length of the nose not affording good visibility over the nose on landing. Although there really is no useful information over the nose on any landing.


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## renrich (Feb 3, 2010)

The cockpit was moved back in order to put the fuel tank in the fuselage and over the wing. That allowed the CG and the CL to coincide which is desirable. Also the usage of fuel caused no appreciable change in the CG. The cockpit was as far foward as it could be given the location of the fuel tank. There was no room for the fuel tank to be under the cockpit as in the F6F and P47.


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## Loiner (Feb 23, 2010)

I've always liked the look and power of the Corsair, and finally picked up my first model kit of one at the weekend. I'm now taking an interest in it and will do a bit of research (as with all models I've collected). 

As the engine was the same 2000hp P&W Double Wasp as the Hellcat, was the performace of the Corsair much better than the Hellcat? They obviously had a wider tracked main undercarriage which would make landing more stable, and larger propeller and cleaner airframe allowing a better max speed at medium altitudes, but it has been mentioned earlier in this thread that they were more costly to build. According to Wiki, similar numbers (about 12,500 of each were built), both entering service in '43. The main operational difference seemed to be the Corsair not being the best for carrier operations so more suited to mainly land based (but carrier capable) Marine use, whereas the Hellcat was more suited as the Navy carrier based aircraft.

To me, the Corsair is the more glamorous of the two. What do others think?


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## renrich (Feb 23, 2010)

The various models of the Corsair were faster at most altitudes, faster climbers, had better roll rates and were better at dive bombing( because the landing gear was able to be used as dive brakes, the Corsair was only slightly less accurate than the SBD) than the Hellcats. The Hellcat was somewhat less vulnerable to battle damage, was more forgiving to the more poorly trained pilot and was a little easier to maintain. One pilot said something like, "the Hellcat was a tame ***** cat, the Corsair was a high strung predator." The Corsair, when first flown, was a cutting edge design, using an engine still under development and a newly designed prop. It was also exploring flight regimes that were somewhat unknown. It had a long gestation period. The Hellcat, being a later and somewhat less sophisticated design went from the drawing board to operational status in a very short time.


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## Milosh (Feb 23, 2010)

operator18 said:


> Don't fell bad. I've spent some time around a f4u-4b and I don't know what it is 90 degrees to either. The cross section is not round for the entire length of the cord.



I would suggest perpendicular to the fuselage where the wing attaches to the fuselage.


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## Loiner (Feb 23, 2010)

Thanks Renrich, that's the impression I was getting from various sources; that the Corsair was a bit more of a wild beast to be tamed but with extra bite when handled with gained experience, whereas the Hellcat was a calmer more forgiving machine to fly, still an excellant fighter but perhaps didn't push the boundaries as far as the Corsair could.

Was the Hellcat a completely new design to the Wildcat, or just upgraded and up-engined?


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## DAVIDICUS (Feb 23, 2010)

"_The Hellcat was somewhat less vulnerable to battle damage, ..._"

Start at post #263 and follow the discussion regarding the "somewhat less vulnerable" issue.

http://www.ww2aircraft.net/forum/av...f4u-4-corsair-superior-738-18.html#post526511

The USN found that Corsairs were 58% more likely to be losses from AA fire than Hellcats when actually hit by AA during the same time period, flying from the same carriers and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie."


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## renrich (Feb 25, 2010)

Notwithstanding the statistics, the fact is, that the Navy chose the Corsair over the Hellcat. AFAIK, no Hellcats served in Korea, the Corsair was heavily involved. The Hellcat was a completely new design over the Wildcat although there was a family resemblance. The Hellcat was much larger, designed for a larger engine and with a totally different landing gear layout.


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## DAVIDICUS (Feb 25, 2010)

There is a good discussion in that thread regarding the Navy's decision, which was well before the vulnerability issue was known, and the reasons for that decision. In hindsight, the Hellcat would have probably performed better than the Corsair in Korea (It would have done the job equally well and without the very serious vulnerability issue.) 

Basically, the USN data compiled from over 22,000 sorties reveals that under comparable apples to apples conditions, for every *10* Hellcats lost, there were *16* Corsairs lost. To say that the Hellcat was "somewhat less vulnerable" is akin to saying that the F4U-1D Corsair was "somewhat less fast" than the Mig-15, which had about a 58% higher top speed. (420mph vs. 668mph)


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## renrich (Feb 26, 2010)

It strains credulity to think that the Navy did not know about the supposed Corsair vulnerabilitiy issues long before the statistical data which some "experts" on this forum are so fond of quoting was available. The Navy and it's pilots knew as soon as the F4F4 was operational that the six gun design Grumman came up with at the insistence of the British was unsatisfactory and in fact a few F4F4s were built going back to the four gun configuration. The data that purports to show the Corsair vulnerability was published in June of 1946. If the data was as damning as is claimed then surely Vought would have been asked to make an effort to cure the vulnerability problem. The AU, a dedicated ground attack AC did relocate the oil cooler which is supposed to be the culprit but nothing was done in that area on post war F4U4s and F4U5s.

The facts are that the Corsair outperformed the Hellcat in almost every way. If one reads the comparison between a captured FW190 and a Hellcat and Corsair, even though both Navy fighters were adjudged to be able to cope with the FW, the Corsair had the performance edge in every way. The Corsair was a better air to air gunnery fighter because besides being faster, a better roller and climber it had much better control modulation. 

The fact is that, in spite of "expert" claims to the contrary, the Hellcat and Corsair flew almost the same number of sorties in WW2, something over 60000 each and only 553 Hellcats were lost to AA and only 349 Corsairs so neither AC seemed to be particularly vunerable to AA. The Hellcat had 340 operational losses which was 61% of the AA losses and the Corsair 230 which was 66% of the AA losses and one supposes that our pilots were not purposely trying to destroy our aircraft like the Japanese were. Some "experts" will claim that the bulk of Corsair air to ground sorties were flown against undefended islands but those "experts" ignore the fact that in the Philipines campaign the Corsairs carried by far the heaviest load and those targets were heavily defended.

To say that," in hindsight, the Hellcat would have probably done better in Korea" when no reputable author or source I have ever heard of has drawn that conclusion seems to be a stretch to me. However, everyone is entitled to an opinion, especially on this forum with all of us "experts."

IMO, when the Navy made the decision to replace Hellcats with Corsairs on carriers, the Navy knew about the strong and weak points of both fighters and made the correct decision based on their immediate and long term priorities.


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## DAVIDICUS (Feb 26, 2010)

"_It strains credulity to think that the Navy did not know about the supposed Corsair vulnerabilitiy issues long before the statistical data which some "experts" on this forum are so fond of quoting was available._"

This was already addressed in the thread. I'm not sure what else can be said. Again, for those interested in reading the discussion, start with post #263:

http://www.ww2aircraft.net/forum/av...f4u-4-corsair-superior-738-18.html#post526511

"_The facts are that the Corsair outperformed the Hellcat in almost every way. If one reads the comparison between a captured FW190 and a Hellcat and Corsair, even though both Navy fighters were adjudged to be able to cope with the FW, the Corsair had the performance edge in every way._"

Yes! And don't stop there. Clearly, the Navy actually knew about the tremendous performance advantage too. And yet, the Navy declared the following, with the benefit of hindsight, after WWII:

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

and

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

Comparing the Hellcat and Corsair, during the same time period, flying from the same carriers and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie," the Corsair had a 58% greater chance of not making it back when actually suffering AA damage. Given the enormous performance advantage of the Corsair, it would indeed take a huge vulnerability weakness (like a 58% higher probability of not making it back when suffering AA damage) to cause the Navy to declare that the Hellcat was actually superior in combat "chiefly because of its greater ability to survive damage."

_"The fact is that, in spite of "expert" claims to the contrary, the Hellcat and Corsair flew almost the same number of sorties in WW2, something over 60000 each and only 553 Hellcats were lost to AA and only 349 Corsairs so neither AC seemed to be particularly vunerable to AA. The Hellcat had 340 operational losses which was 61% of the AA losses and the Corsair 230 which was 66% of the AA losses and one supposes that our pilots were not purposely trying to destroy our aircraft like the Japanese were. Some "experts" will claim that the bulk of Corsair air to ground sorties were flown against undefended islands but those "experts" ignore the fact that in the Philipines campaign the Corsairs carried by far the heaviest load and those targets were heavily defended."_

When you mix together, for both aircraft, all missions over the entire war, it becomes impossible to disentangle and control for factors that interfere with a comparative analysis ... about anything. The more than 22,000 sorties during the same time period, where both aircraft operated from the same carriers, flying missions under the "same conditions" in "comparable operations" and where the two aircraft received "about the same number of hits [AA] per sortie," enable us to draw valid conclusions about the comparative vulnerability to AA fire. The Navy thought so too and pointed out that under apples to apples conditions, the Corsair was 58% more likely not to return from combat.

"_To say that," in hindsight, the Hellcat would have probably done better in Korea" when no reputable author or source I have ever heard of has drawn that conclusion seems to be a stretch to me. However, everyone is entitled to an opinion, especially on this forum with all of us "experts."_"

I'm going to defer to JoeB here and just cut and paste his comments from post #319 of that thread:

*Re: F4U and F6F ground fire vulnerability and mountain or mole hill, it is what it is. It's as statistically clear as it ever would be that the F4U was significantly more vulnerable. How important that was would depend a lot on what the key missions were. Early in WWII it wouldn't have been very important at all. By 1945 it was somewhat important. In a war where carrier planes conducted constant air strikes with essentially no air or anti-ship threat for months on end (see: Korea) it was a relatively quite serious issue. It was too late to bring the F6F back, but it almost surely would have been a better a/c for the F4U's mission in Korea. Again see 1945 stats, F4U's did *not* carry more ordnance per sortie from carriers than F6F's, not in actual practice. And in Korea, typically, high value targets weren't being smashed by a few decisive strikes. The realistic goal was harassing the enemy, gradually inflict casualties and damage it was hoped, and only occasionally, perhaps, scoring any really satisfying success. The heavy losses of beat up old F4U-4's were not such a big deal, they were going to the boneyard soon anyway, but the losses of pilots was more of an issue, even from a completely non-sentimental POV of trying to re-expand naval aviation for the Cold War. To this was added the F4U's inherently higher accident rate, especially in the more difficult operating conditions typically faced by carrier a/c in Korea compared to the Pacific War, more especially in the winter time.

But as shown by all these debates here, it wasn't hard at all to miss the fact of greater F4U vulnerability before the stats were accumulated (or in these threads, before people are fully aware of them and just how apples to apples they are). Even afterward naval air thinking emphasized dashing hell-for-leather wars like WWII. And even in the actual conditions of Korea once apparent, leadership simply had a blind spot about air crew losses that didn't make a lot of sense compared to the actual results achieved. It's hard to explain certain decisions in KW any other way (goes for the USAF as well).*

http://www.ww2aircraft.net/forum/av...f4u-4-corsair-superior-738-22.html#post532571


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## tomo pauk (Feb 27, 2010)

I'd point to some stuff re. F6-F F-4U as competitors for place on post-WW2 carriers:
-I see a way of thinking for post-WW2 composition of carrier air wing as this: F8-F as dedicated fighter, F4-U as multirole plane, and AD-1 as dedicated bomber. In the end F8-F barely managed to be a CV asset, leaving F4-U as dedicated fighter.
-Raw performance (as a fighter) of latest F4-U was much greater then of latest F6-F, so any concievable, post-WW2opposition would present a problem for F6-F. 
-Grumman started producing F8-F in mid 1945, which implies that F6-F would be no longer produced on Grumman's lines.

Question: were the post-WW2 Corsairs modified in order to increase the resistance to AAA?


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## riacrato (Feb 27, 2010)

The problem was the placement of the cooler right? So any attempt at fixing that would result in significant re-design.

The decision for the Corsair over the Hellcat might root in the fact that they had to choose a multirole fighter. I think the Corsair left more room for additional equipment such as radar and so on. Certainly the Corsair has more of chance to succeed against the final generation of piston fighters (Ki 84 and hypothetically fighters comparable to Ta 152, Yak 3 or La 9). In Korea they soon were not really used as fighters any longer, though. It still carried a large payload, but for everyday work it seems the F6F might indeed be a overall easier and less troublesome bird, even in Korea. Its speed disadvantage was not really important as both would be outclassed by the jets by far.


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## Hollywood (Feb 28, 2010)

This seems to have become a comparison of the two aircraft, so here's my "two cents"....... From my work here at NMNA we've taken apart and rebuilt many of both types. The aircraft are two completely different birds. The Corsair evolved from a high performance design for a pursuit aircraft or "fighter" in 1935.
The Hellcat was designed as a replacement for the F4F Wildcat designed in the same year and put into production in 1940 when the Hellcat was already on the drawing board as a revamped F4F but ended up as a new design and really ramped up when it was found how far behind the Japanese designed Zeke it really was. Due to tactics the wildcat held it's own but wasn't near the performance necessary to overcome it. The development of the Hellcat finalized after the example of a Zeke was recovered at Acutan in the Aleutian Islands and testing was accomplished. The wing was the primary change being enlarged to enhance maneuverability. This had the added effect of enhancing "flyability" and helped scores of new pilots to an easy transition to type. I've spoken with many pilots who flew both types and the consensus is that the F6F is a big friendly bear and the F4U is a wild beast. The biggest difference is the cooling in the wing root of the Corsair with a slim fuselage and the Hellcat cooling is in the cowling and fuselage resulting in the large rounded fuselage with the high rib on top for lateral stability. It was more than an equal for the Zeke(or "Zero") and took the fight to them from 1 August 1943.
Marine units had been flying the F4U from land bases for about 3 Months by then as Carrier Trials for the type hadn't been positive and we sent it to the British who learned how to fly it from Carriers first with the difficult stalling characteristics and vicious "Bounce" on landing........


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## renrich (Mar 7, 2010)

Hollywood, your analysis of the two AC is interesting and informative. However, I believe that the story of the FAA being the first to tame the Corsair for carrier ops is a myth. If you study the chronology of Corsair ops in Dean, "America's Hundred Thousand," Blackburn's VF squadron had readied the Corsair for carrier ops before the FAA had even tried to operate the Corsair from carriers. In addition, there is a training film on Zeno's of the F4U1 which shows a field carrier landing employing the curving base and short final which has been credited to the FAA. That F4U1 has insignia proving the film was probably shot long before the FAA got their hands on Corsairs. The two primary drawbacks for Corsairs carrier ops were the poor visibility over the nose and the excessive bounce of the main gear oleos. The visibility problem was alleviated somewhat in the F4U1As by the revised canopy and raising the pilot seat and the oleos were field modified by trial and error and eventually on production models. Also in Dean, there are several remarks by pilots of Hellcats which allude to it's marginal performance characteristics over Japanese opposition. That big wing and deep fuselage on the F6F, compared to the F4U, was paid for in a diminuation in performance.


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## mcoffee (Mar 9, 2010)

Hollywood said:


> The development of the Hellcat finalized after the example of a Zeke was recovered at Acutan in the Aleutian Islands and testing was accomplished. The wing was the primary change being enlarged to enhance maneuverability. This had the added effect of enhancing "flyability" and helped scores of new pilots to an easy transition to type.



That the Aleutian Zero had any influence on the design of the Hellcat is an absolute myth. The contract firmly fixing the Hellcat configuration was signed six months prior to the crash of the Aleutian Zero. 

The Aleutian Zero was an A6M-2 flown by Petty Officer Koga who made an emergency landing June 3, 1942. Koga was killed when the Zero overturned. It took the Navy five weeks to salvage the aircraft, another seven weeks to get it to NAS North Island in San Diego, and to complete major repairs including locating a replacement propeller. The Aleutian Zero arrived in San Diego in August and was first flown by the USN on 20 September 1942.The Navy/AAF comparative tests which disclosed the 'secrets' of the Zero were not completed until December 1942. 

The F6F configuration was firmly fixed on January 7, 1942 when the Navy awarded a contract for 1,264 Hellcats. Airframe design had begun in June 1941. The XF6F-1 with the stop-gap R-2600 engine first flew June 26, 1942 - before the Zero was recovered from the Tundra. The XF6F-3 with the R-2800 engine flew July 30, 1942, a month before Koga's Zero arrived in San Diego, and two months before it was flown. 

While the captured Zero was important in the refinement of tactics, it provided no direct input into the Hellcat design.


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## mcoffee (Mar 9, 2010)

renrich said:


> ...I believe that the story of the FAA being the first to tame the Corsair for carrier ops is a myth. If you study the chronology of Corsair ops in Dean, "America's Hundred Thousand," Blackburn's VF squadron had readied the Corsair for carrier ops before the FAA had even tried to operate the Corsair from carriers. In addition, there is a training film on Zeno's of the F4U1 which shows a field carrier landing employing the curving base and short final which has been credited to the FAA.



Correct on both counts. First carrier-based combat usage of the Corsair was with the USN, and by night fighters no less! VF(N)-101 took their F4U-2's aboard _Enterprise_ and _Intrepid_ (four plane groups on each boat) in January '44 and began combat operations with the fast carriers. First British combat use of carrier-based Corsairs was April '44.

The curved approach pre-dates the Corsair. This was the standard approach from the days of biplane carrier fighters. Can't say whether or not the British first implemented it, but it was not with the Corsair.


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## renrich (Mar 9, 2010)

Actually Corsairs operated from carriers in combat during the Battle of the Solomon Sea, November, 1943. This was not official with the bureaucrats in the US but land based Corsairs from VF17 had tail hooks attached and after protecting the fleet during raids on Rabaul, landed on carriers in order to refuel and then go back to land bases. VF17 claimed 18.5 kills for two losses. VF17 with F4U1As was deployed on Bunker Hill in September, 1943, but was off loaded at Pearl Harbor and diverted to land base duty.


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