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

[drgondog]

This is from Brassey's Air Combat Reader:

Clay - a short note on this. ANY single engine a/c with a hit to the oil cooler is dead meat...the question debated above is 'how much more vulnerable was a Corsair oil cooler than a Hellcat based on protection?

I think most have concluded that fewer 'golden BB's' were liable to make it through to the F6F oil cooler.

For Dogfighting below 20k feet I'd take the Corsair. For all other things, including ground attack, I'll take the more durable and more versatile Jug.

Until the late model Jugs were designed with internal wing tanks, the range of the Jug with ordnance was significantly less - the Corsair had the edge on the P-47 until the N.. implication - F4U and P-47 load were equal, F4U more agile on deck without load, (or with one), F4U could carry load further until last 5 months of WWII, F4U could escort effectively any USAAF bomber if required including B-29 but 47N would have clear edge at B-29 altitudes.

F4U could operate from a carrier, P-47 could take off but not return.

How is P-47 more versatile

IIRC the Jug shot down more enemy aircraft than the Corsair.

I believe you are correct. The Jug, however fought with USAAF (and RAF, RAAF, RNZAF) in all theatres(ETO, MTO, CBI, PTO) except Alaska. The Corsair foughtonly in PTO except for very few in RN which didn't amount to anything in the air war in ETO.

I have always attributed some of the Mustang's success in shooting down more planes to its endurance, i.e. its ability to take the fight to the enemy sometimes when and where he least expects it. I think increased range created more opportunity to engage the Germans, more engagements led to more kills.

The Me 110 and Mosquito with tanks had nearly or more than same range, Ditto P-38 - range is important but performance at the edge of that range is what distinguished the Mustang

Both the Corsair and the Jug were equipped with the excellent but fuel hungry R-2800, so I think that's moot.

What gave the P-47 the edge at high altitude (turbo supercharger) was not designing for internal fuselage fuel. The F4U didn't need the very high altitude performance but did need the range so it had internal fuselage fuel and greater range until the late model P-47D.

I can't prove 8 guns made a big difference, but several WWII pilots I've heard interviewed said they thought it did.

I would rather have 8 than 6 (or four) depending on performance degradation for the extra weight - as a trade off for having more lead to spray. I suspect it made more difference for the guy that didn't shoot as well - (which would be most fighter pilots).

I recall some conversationsamong the Mustang aces in which speculation about 4x 50 in the P-51D coupled with the explosive .50 cal round might have been a really good version of the D.. for the" Experten". I also know the results of the explosive .50 cal were mixed, ranging from acceptable to poor.

 

[renrich]

The P47 was the original "Ground Hugger" and required a much longer distance to get off the ground than the Corsair. That would have been a serious handicap when operating from short landing strips in the Southwest Pacific with the density altitudes prevelant there. In fact, in the ETO, P47s often took off with less than a full load of ammunition because of weight considerations. The fact is that the Hellcat and Corsair flew about the same number of sorties in the PTO. The Hellcat had 823 combat losses and the Corsair had 538. My book is packed right now but assuming that around 11000 of each type were built in WW2 ( which is close), 7% of Hellcats were lost to enemy action, 5% of Corsairs were lost to enemy action. The Hellcat had more operational losses because it had more carrier based sorties. The P47 had a total of 3662 kills in the ETO, MED and PTO. The Corsair had 2155 kills in the PTO only. The P47 had 697 kills in the PTO. THe Corsair especially early in the war with internal wing tanks had a much longer range than the P47. The Corsair could and did dive bomb, the P47 could not. The Corsair was superior air to air from 25000 feet down where most ACM took place. The P47 began to have better performance above 25000 feet. The Corsair could operate from carriers. The P47 could not. The Corsair could operate from small airfields with bigger combat loads than the P47. To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane. The Corsair, operating from both small forward area landing strips and carriers, carried out the majority of the close air support strikes in the early part of the Korean War. To me, that speaks well for it's versatility.

 

[davparlr]

.Until the late model Jugs were designed with internal wing tanks, the range of the Jug with ordnance was significantly less - the Corsair had the edge on the P-47 until the N.. implication - F4U and P-47 load were equal, F4U more agile on deck without load, (or with one), F4U could carry load further until last 5 months of WWII, F4U could escort effectively any USAAF bomber if required including B-29 but 47N would have clear edge at B-29 altitudes.

This is true up until about April, '44. The F4U-1 internal fuel was 341 gallons and the pre-P-47D-25 was 305 gallons. After April, 44, the F4U-1D and on had only 237 gallons internal whereas the P-47D-25 through M had 370 gallons. The P-47N had 550 gallons. So, after April, '44, the P-47D-25 and on, assuming fuel consuption is similar, had better range than any model F4U.

 

[davparlr]

I think that there's no doubt that the F4U was the superior aircraft for the PTO nor do I think there is any doubt that the P-47 was the superior aircraft for the ETO bomber support roles. As for ground support, both were outstanding.

 

[drgondog]

This is true up until about April, '44. The F4U-1 internal fuel was 341 gallons and the pre-P-47D-25 was 305 gallons. After April, 44, the F4U-1D and on had only 237 gallons internal whereas the P-47D-25 through M had 370 gallons. The P-47N had 550 gallons. So, after April, '44, the P-47D-25 and on, assuming fuel consuption is similar, had better range than any model F4U.

Dave I agree the data - I forgot the -25 was the first wet wing D. For whatever reason, that did not alter the role of the P-47D re: no deep penetration escort until late summer/early fall 1944 and that was only a few stretch runs to Leipzig area.

The average long range mission through 1944 for both the F4U-4 and P-47D-25 and newer remained pretty much the same as mid 1944. Differences between the two for Drag and Gross weight at take off had more negative effect on the 47. Empty the F4U was 800+ pounds lighter, with guns, fuel and ammo about 1000 pounds lighter. I don't have comparable drag figures for cruise so my point is speculative.

 

[drgondog]

I just did a quick look at various air to air and air to ground details for the F4U in the PTO and P-47s and P-51s in 8th AF.

Difficult to draw conclusions as the missions and adversary were different -( IMHO tougher air battlesand strafing hazards by far in ETO), but

F4U - 2140+ air victories versus 189 lost in the air and 349 lost to flak
P-51 -3328 air victories versus 326 lost in the air and 570 lost to flak (3212 Ground scores)
P-47 1550 air victories versus 214 lost in the air and 200 lost to flak ( 739 Ground scores)

 

[davparlr]

Dave I agree the data - I forgot the -25 was the first wet wing D. For whatever reason, that did not alter the role of the P-47D re: no deep penetration escort until late summer/early fall 1944 and that was only a few stretch runs to Leipzig area.

You were right the first time. The N was the first with wet wings. The -25 and on got additional fuel by increasing the volume of the main tank (space was added at the top of the tank).

The average long range mission through 1944 for both the F4U-4 and P-47D-25 and newer remained pretty much the same as mid 1944. Differences between the two for Drag and Gross weight at take off surely had some effect.

Both aircraft had similar clean drag characteristics with the F4U slightly cleaner. Also, both could carry quite a load, and, as such, were quite flexible.

 

[drgondog]

You were right the first time. The N was the first with wet wings. The -25 and on got additional fuel by increasing the volume of the main tank (space was added at the top of the tank).



Both aircraft had similar clean drag characteristics with the F4U slightly cleaner. Also, both could carry quite a load, and, as such, were quite flexible.

Thanks for the correction - I was pretty sure the -25 was not appreciably longer in range but you have an excellent grasp of the published facts.

 

[Daviducus2]

I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right? The Navy's own apples to apples data established a very large disparity in survivability between the Hellcat and Corsair.

Speculation - Perhaps others noticed what we now know was a serious problem with the Corsair and attributed it to the wing tanks when it was actually the oil cooling design? Also, I wonder if at least part of the oil cooling system's vulverability (assuming this was the issue) was a function of it being spread over a much larger area than the Hellcat and Thunderbolt which shared a different design.

As for ground support, both were outstanding.

Yes but in my opinion the P-47 was superior in the air to ground realm because of the data that found that in an apples to apples comparison, for every 10 Hellcats lost to AA fire, 16 Corsairs were lost. That's a pretty startling and troubling statistic. I know that if I were a pilot with the choice of pounding ground targets with either a Hellcat or Corsair, I would choose the Hellcat as I want to make it back and my chances of not making it back if I actually take AA fire are 58% higher for the Corsair.

Assuming the culprit here is the oil cooling design which confers a tremendous advantage to the Hellcat and because the Hellcat and Thunderbolt share the same oil cooling design and there are no known issues (none that I know of) with survivability that are Thunderbolt specific, I would prefer the Thunderbolt for ground support as it would "appear" to have more than a significant edge in survivability over the Corsair.

On a related note, the oil tank on the P-47N was 40 gallons! That's more than twice the 18 gallon F4U-4 oil tank. The Hellcat's oil tank was also 18 gallons. One can see how an additional 22 gallons which is 22% more than the Corsair's oil tank to begin with could come in handy if you are leaking oil due to combat damage.

 

[davparlr]

Thanks for the correction - I was pretty sure the -25 was not appreciably longer in range but you have an excellent grasp of the published facts.

Books help. America's Hundred-Thousand is a great reference!

 

[davparlr]

On a related note, the oil tank on the P-47N was 40 gallons! That's more than twice the 18 gallon F4U-4 oil tank. The Hellcat's oil tank was also 18 gallons. One can see how an additional 22 gallons which is 22% more than the Corsair's fuel tank to begin with could come in handy if you are leaking oil due to combat damage.

I suspect the extra oil was needed for the extended range of the N. Those radials really liked oil.

 

[Catch22]

I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right?

No, it's not. They removed the wing tanks from the -1D because by the time it was introduced the vast majority of all operations were from carriers, close to the objectives. They felt they were not needed, and removing them increased performance, notably speed. They were able to do this because of the two hard points on the bottom of the wing roots that were introduced with the -1D, which could be used to carry drop tanks that replaced the wing tanks. The advantage of the drop tanks was, well, you could drop them if needed, so you not only retained the range of the earlier models, but you also got the performance boost.

 

[Daviducus2]

I confess that Wikipedia was the source of my misunderstanding:

Additionally, the role of fighter-bombing was a new task for the Corsair and the wing fuel cells proved too vulnerable and were removed.

Weren't the wing tanks non-self sealing though? That is indicated in the article as well.

 

[Catch22]

That may very well have been a reason as well, but the main one was the lack of need for range. I'm not sure about the self-sealingness of the tanks, however I haven't really heard of the wing tanks being an issue at all during combat. Come to think of it though, I do remember reading something about pilots purging them before combat.

 

[Clay_Allison]

The P47 was the original "Ground Hugger" and required a much longer distance to get off the ground than the Corsair. That would have been a serious handicap when operating from short landing strips in the Southwest Pacific with the density altitudes prevelant there. In fact, in the ETO, P47s often took off with less than a full load of ammunition because of weight considerations. The fact is that the Hellcat and Corsair flew about the same number of sorties in the PTO. The Hellcat had 823 combat losses and the Corsair had 538. My book is packed right now but assuming that around 11000 of each type were built in WW2 ( which is close), 7% of Hellcats were lost to enemy action, 5% of Corsairs were lost to enemy action. The Hellcat had more operational losses because it had more carrier based sorties. The P47 had a total of 3662 kills in the ETO, MED and PTO. The Corsair had 2155 kills in the PTO only. The P47 had 697 kills in the PTO. THe Corsair especially early in the war with internal wing tanks had a much longer range than the P47. The Corsair could and did dive bomb, the P47 could not. The Corsair was superior air to air from 25000 feet down where most ACM took place. The P47 began to have better performance above 25000 feet. The Corsair could operate from carriers. The P47 could not. The Corsair could operate from small airfields with bigger combat loads than the P47. To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane. The Corsair, operating from both small forward area landing strips and carriers, carried out the majority of the close air support strikes in the early part of the Korean War. To me, that speaks well for it's versatility.

The P-47 had a poor climb rate initially, this was solved with the switch to "paddle-blade" props. After that they got off the ground well enough and 190 pilots could no longer reliably climb away.

 

[drgondog]

I recall reading that they removed the wing tanks from the Corsair thus significantly reducing its range because they thought the wing tanks made the Corsair too vulnerable to being shot down. Is this right? The Navy's own apples to apples data established a very large disparity in survivability between the Hellcat and Corsair.

Speculation - Perhaps others noticed what we now know was a serious problem with the Corsair and attributed it to the wing tanks when it was actually the oil cooling design? Also, I wonder if at least part of the oil cooling system's vulverability (assuming this was the issue) was a function of it being spread over a much larger area than the Hellcat and Thunderbolt which shared a different design.

As for ground support, both were outstanding.

Yes but in my opinion the P-47 was superior in the air to ground realm because of the data that found that in an apples to apples comparison, for every 10 Hellcats lost to AA fire, 16 Corsairs were lost. That's a pretty startling and troubling statistic. I know that if I were a pilot with the choice of pounding ground targets with either a Hellcat or Corsair, I would choose the Hellcat as I want to make it back and my chances of not making it back if I actually take AA fire is 58% higher for the Corsair.

Assuming the culprit here is the oil cooling design which confers a tremendous advantage to the Hellcat and because the Hellcat and Thunderbolt share the same oil cooling design and there are no known issues (none that I know of) with survivability that are Thunderbolt specific, I would prefer the Thunderbolt for ground support as it would "appear" to have more than a significant edge in survivability over the Corsair.

On a related note, the oil tank on the P-47N was 40 gallons! That's more than twice the 18 gallon F4U-4 oil tank. The Hellcat's oil tank was also 18 gallons.

That would be about range difference

It is simply impossible to draw metric based conclusions between P-47 and F4U in context of survivability.. they didn't have the same mission, weren't flying against same targets, etc.

It is hard enough to compare Mustang to TBolt in 8th AF.

 

[Clay_Allison]

It is simply impossible to draw metric based conclusions between P-47 and F4U in context of survivability.. they didn't have the same mission, weren't flying against same targets, etc.

It is hard enough to compare Mustang to TBolt in 8th AF.

He was drawinig conclusions based on the Hellcat though. He only extrapolated similarities between the Hellcat and the P-47.

 

[DAVIDICUS]

To me, the oil cooler issue might be a little like making a mountain out of a mole hill. The Navy did not think it was a big enough issue to ask Vought to change the location on post war production Corsairs until the AU which was a dedicated ground attack plane.

More like a mountain out of a slightly smaller mountain. You are assuming that the Navy knew about the problem, assuming it was the oil cooler as opposed to some other Corsair specific issue. We can see that it didn't occur to the Navy until mid 1946 that Corsairs were 58% more likely to be losses from AA fire than Hellcats when actually hit by AA in the same time period, flying from the same ships and flying missions under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie." In fact, even if you don't control for these variables, Corsairs were still dropping from the sky at far higher rates than Hellcats.

At any rate, if we chalk it up to some other issue specific to the Corsair, that apparently escaped the Navy's notice too.

I for one do not find it hard to believe that the fog of ongoing war would obscure the vulnerability of the Corsair. Especially when probably no one was looking at loss rates under comparable circumstances or probably comparative loss rates at all. After all, both aircraft were very sturdy, shared the R-2800 engine and were similarly unbelievably successful against their Japanese opponents.

 

[JoeB]

That may very well have been a reason as well, but the main one was the lack of need for range. I'm not sure about the self-sealingness of the tanks, however I haven't really heard of the wing tanks being an issue at all during combat. Come to think of it though, I do remember reading something about pilots purging them before combat.

The F4U-1's wing tanks were non-self sealing. So, carrying wing fuel (124 gal) and a 175 gal center line drop tank in F4U-1 was roughly equivalent to carrying 2*150 gal drop tanks in an F4U-1D or -4. Either way it was viewed as highly desirable to burn off or drop unprotected fuel before entering air combat (though it wasn't always the case, USN fighters sometimes retained their drop tanks in air combat). And, either way the full load meant more than 1/2 the fuel was unprotected (230-odd gal protected internal tank), and again assuming a plan to use only protected fuel in combat, the radius was determined by the capacity of the protected internal tank to fight and get home. Extra unprotected fuel just allowed more pre-combat patrol time at that max radius.

The F4U-1 arrangement allowed the flexibility to enter combat with unprotected fuel, if necessary, without extra drag. The -1D arrangement had more flexibility to get rid of the fuel.

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

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

Joe

 

[Daviducus2]

Seriously though, the ability to keep facts from interfering with preconceived fantasy is almost beyond belief.
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[Edited for content.]