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

[MikeGazdik]

Hmmmm ...... some people at the Best Pacific Fighter thread say the Hellcat was tops.

With out being able to pull out facts and figures, I would say the Hellcat may have been the best in the Pacific theatre. But obviously these are the Japanese planes that were far inferior, except a couple of the later models which were not built in enough numbers, or flown by experienced enough men, to matter.

I know it has been written otherwise, but I just don't see the Hellcat stacking up against the top Luftwaffe planes, as well as the P-51 or P-47. I think the Hellcat lacked too much speed vs the Focke Wulf and Messerschmitt. And I think its performance at 25k and above was far worse than the Messerschmitt, Mustang , and Thunderbolt. I think from what I recall the Hellcat could turn, what about the roll?

Im not saying the Hellcat is incapable, it was obvously darn good. But I just don't see it being able to out perform the Republic or North American product in Europe. Or the Spitfire for that matter.

 

[renrich]

Mike, look up Mike Williams' reprint of a US Navy evaluation of the F6F3 and F4U1 versus an FW190A4 for the answer to your question. Vmax is not always the determinant in a fight.

 

[Daviducus2]

In terms of performance, I don't think the Hellcat could hold a candle to the Corsair but the USN collected lots of data where both Corsairs and Hellcats flew from the same ships at the same time in 1945 against the same targets. The results of this data are surprising - at least to me.

See the "Hardest plane to take down in WW2" thread for an earlier discussion on this subject. I cut and pasted the relevant text of the report below.

Apparently the Corsairs were more than 50% more likely to become losses after suffering AA fire than the Hellcats. (41% vs. 26%) I have also heard some speculation that it had to do with the different oil cooler layout on the Corsair, the design of which was eventually changed in post WW2 production variants as the problem persisted into the Korean conflict.

From Naval Aviation Combat Statistics, WWII

Page 58:

Thus comparisons are valid between the carrier F6F and F4U totals because they generally operated from the same ships during the same period.
...
Certain tentative conclusions may be reached from these two tables:

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

And on Page 79, Note (e) to Table 29

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.

 

[syscom3]

Off topic, but I suspect the F4U-4 was able to take on the last of the Japanese fighters that were being produced at the end of the war (assuming they were flown by good pilots, had good gasoline and the plane was built correctly).

The F6F wouldnt have been able to handle them.

 

[Vincenzo]

From Naval Aviation Combat Statistics, WWII

Page 58:

Thus comparisons are valid between the carrier F6F and F4U totals because they generally operated from the same ships during the same period.
...
Certain tentative conclusions may be reached from these two tables:

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

And on Page 79, Note (e) to Table 29

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.

for page 79
the trouble is attacking a target with enemy AA it too few for tell "under the same condition" as the compilators of report, enemy AA can be a single 7,7 mg or twelve 25 mm guns i dont' see the same condition.

for page 58
i don't see advantage for hellcat, (other the trouble on each comparison)

 

[Daviducus2]

http://www.history.navy.mil/download/nasc.pdf

See the table on page 78 and the following note "e" on page 79. Note the number of sorties flown from carriers in 1945 with AA present. 22,000 sorties for both aircraft. The report earlier states that the two aircraft were operating from the same ships in 1945 on this data point.

Note (e) - "... 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."

I think the data speaks for itself and the report does not misread or misevaluate the data. I for one have never seen a more apples to apples collection of data on aircraft combat performance. There is no reason to assume facts not in evidence or entertain notions like Hellcats having faced more 7.7mm fire and Corsairs more 20mm fire.

We all accord great weight to individual aircraft performance tests on certain standardized parameters even though the specific aircraft used in the test could deviate from the norm for that aircraft model. With a massive data population such as here, no such individual aircraft deviations could skew the totals and single mission specific factors that favor one over the other would be washed out in the thousands of sorties flown.

 

[JoeB]

See the table on page 78 and the following note "e" on page 79. Note the number of sorties flown from carriers in 1945 with AA present. 22,000 sorties for both aircraft. The report earlier states that the two aircraft were operating from the same ships in 1945 on this data point.

I agree, I find the resistance to this data point very puzzling, and more so the more it's explained just how broad and side by side it was. Rarely is any comparison between two planes as broad and 'apples to apples' as that one. And it's reinforced anecdotally by the F4U's poor reputation for ground fire vulnerability in Korea, and eventual redesign of oil cooler arrangement and uparmoring (in AU-1) to deal with it. There is no valid reason to to doubt that conclusion: F4U distinctly more vulnerable to ground fire than F6F.

On P-47N, I spoke once to the USAF pilot who scored the first USAF victory over a MiG-15 in Korea in F-80 (that the Soviets agree happened, a few days after Russell Brown's famous combat, in which no MiG was actually downed per Soviet records). By interesting coincidence he also flew combat missions over Korea late in WWII, from Ie Shima (near Okinawa) in the P-47N. He was convinced the P-47 in general was superior to the P-51 and P-38, especially the P-47N. This seems to have been a fairly typical pattern for pilots who mainly flew one type, or only flew one type in combat (and not all that many flew more than one of the P-38, 47 and 51 *in combat*, though some did). I guess he'd think P-47N superior to F4U-4 as well.

Joe

 

[drgondog]

3rd, This fits in nicely with a paperback I am presently re-reading. ( they stay with me forever) Its about an 8th AF pilot that starts out in Thunderbolts, then switches to Mustangs. He pretty much said what it sounded like Snort's father was saying. The Mustang was better, but in the Thunderbolt he felt safer. I guess when things get ugly, and you are on the receiving end, advantage Thunderbolt !

Another great read, thanks to all!

Which book? Ace of the Eighth by Fortier?

 

[DAVIDICUS]

Assuming the massive disparity in survivability between the Hellcat and Corsair was a function of the oil cooling design, as a pilot I think I'd have second thoughts if given the choice between Corsair and Thunderbolt for ground attack / close air support.

 

[renrich]

Yes, it was massive alright, they both flew about the same number of combat sorties although the Corsair dropped more than twice the tonnage of bombs and the Hellcat's were more air to air and the Hellcat lost 553 AC to AAA and the Corsair lost 349 to AAA. Massive, huh?

 

[Daviducus2]

41% vs. 26% means the 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."

41 is .5769 more than 26.

I don't think "massive" qualifies as a mischaracterization but as has been stated above, the data speaks for itself. If you prefer "very large disparity" I stand corrected.

The problem with the point you are making through the data you have posted above is that it lacks the apples to apples aspect of the 22,000 "same conditions" "comparable operations" sorties on which the conclusions in the Naval Aviation Combat Statistics report are anchored.

As JoeB mentioned, the resistance to this is puzzling. I can't think of any other comparative statistical analysis between aircraft that is so well defined and controlled and yet discounted as mere fiction in the absence of a single criticism of the validity of the data. I can't help but wonder what your reaction would be if the situation were reversed such that there were a 58% greater loss rate for the Hellcat. I frankly suspect that if such were the case, you would wholeheartedly agree that such a disparity is indeed "massive."

Am I wrong?

At any rate, I am sure we can agree that the disparity is very large.

 

[JoeB]

Yes, it was massive alright, they both flew about the same number of combat sorties although the Corsair dropped more than twice the tonnage of bombs and the Hellcat's were more air to air and the Hellcat lost 553 AC to AAA and the Corsair lost 349 to AAA. Massive, huh?

Download the NASC document from the link above, and look at the actual tables showing results of side by side operations of the same kind. The F4U operational loss rate *per action sortie* from CV's, in '45, was 50% higher than F6F's rate from CV's in 1945. The AAA loss rate *per sortie encountering AA fire* in carrier operations in 1945 was more than that much higher for the F4U. The ordnance dropped *per strike sortie* in carrier operations in 1945 was almost the same for the two types. Prior to 1945 there is no fair comparison because there was no large number of carrier or land based strike sorties for *both* types in the *same* period, but the 1945 carrier results are a statistically quite large sample. I gave the specific table references for each of those statements in the thread on Pacific Fighter.

It's simply and obviously not valid to counter that evidence with absolute numbers that don't take into account the number of sorties over which a give tonnage or number of losses occurred, and which compare different types of operations rather the same operations.

Joe

 

[Daviducus2]

"... the 1945 carrier results are a statistically quite large sample."

The only thing I would add to JoeB's post is that the data provided is not just a sample of the carrier operations between the two aircraft in 1945 flying from the same ships under the "same conditions" in "comparable operations" where the two aircraft received "about the same number of hits per sortie" but the entire population itself. Thus, the data is not subject to statistical sampling errors that can result in a sample not being reflective of the population from which it is drawn.

 

[renrich]

Some thoughts on the infamous(famous) Corsair vulnerability to ground fire possibly because of the location of the oil cooler. First, let me say that it is obvious that the oil cooler in the Corsair was more vulnerable, especially to ground fire, than that of the Hellcat. The Hellcat's was behind the engine and the Corsair's was in the wing which is further back. Anyone who has done much wingshooting knows that a bird is more likely to get hit in the tail than up front because of not enough lead and that had to be true with AA fire, so the further back something is the more likely it is to be hit. We know that 553 Hellcats were lost to AA while 349 Corsairs were lost to AA. !04 less Corsairs but either number is small considering they both flew around 64-65000 sorties each. We know that the Corsair dropped 15621 tons of bombs and the Hellcat dropped 6503 tons. So the Corsair probably flew around twice as many air to ground missions as the Hellcat unless it carried twice as big a load. We know that the Corsair replaced the Hellcat as the Navy carrier fighter because the Navy thought it was better suited as a fighter and fighter bomber. We know that the postwar production of Corsairs continued to have the oil cooler in the wing until the AU was built and I have been informed by JB, whose information sources seem exhaustive and impeccable, that the F4U7, for the French, had the oil cooler behind the engine also. We know that a statistical study by the Navy of comparable missions flown by both AC in the same time frame and in the same area showed that the Corsair was more likely, statistically, to be shot down by AA than the Hellcat on comparable missions. Two questions arise, why did not the USN insist that the oil cooler be relocated on subsequent production and do we know who was flying the Corsairs and Hellcats in the study done near the end of the war.
In 1953, I graduated from high school and I and 5 other of my doughty friends decided to go down to Padre Island, 140 miles away and camp out on the beach for a week. We got down to Padre, which was not developed as it is today, turned south and drove on the beach for about 20 miles and pitched camp at about sundown. We were awakened the next morning by the sound of aero engines, looked out over the Gulf and there were a bunch of blue airplanes lining up to head toward us. They came over us in a not too shallow dive and over a point inland of us and pulled up. with the sound of guns and small explosions following. Shortly a gray jeep pulled up with two SPs in it. They said,"did you know you are in a Naval Aerial Bombardment Range." We said "no, we did not see any signs.' They said,"you could get the _____ blown out of you here." Us being smart asses, we declined to leave and apparently they couldn't make us so they left and we watched the show. The area of impacts was probably a half mile inland. We went back there late in the afternoon and looked at practise bombs, rockets and empty shell cases. While watching this show several days in a row, we noticed that some of the airplanes held their dive a lot lower than others and we would say,'there is one pulling out early so he must be married."
The reason for this story is that I have an idea that the majority of the Corsairs in the evaluation by the Navy were flown by Marines and the majority of the Hellcats were flown by Navy pilots. The Marines were noted for pressing their attacks in close in order to achieve more accuracy because they were likely to be supporting other Marines on the ground, whereas the Navy did not have quite as much "skin in the game.' That was true in Korea also as the guys on the ground seemed to think the Marine pilots pushed it a little harder than the Navy or Air Force guys. That factor just might account for some(not all) of the apparent difference in vulnerability between the two AC. Another factor in the comparison between the two AC is that the Corsair could and did act as a dive bomber in WW2. I believe that a dive bomber in an 85 degree dive is easier to hit by a resolute gunner( theJapanese were anything if not resolute) than an airplane coming in at a low angle. I have seen combat film of, I believe, Corsairs dive bombing at Okinawa. They looked kind of strange with their landing gear hanging down. Hits in the wing where the oil cooler was would be likely in a dive also.
Incidently, the fun loving pilots of those blue airplanes decided to give us a thrill. One buzzed us in a Bearcat at about 50 feet over the surf while we were swimming and another guy either dropped or fired a dummy something which made a loud splash and geyser in the water about 100 yards away. We got a kick out of it.

 

[Daviducus2]

Note (e) on Page 79 states:

(e) 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.

If we assumed that the Corsairs were flown primarily by daring, committed, "skin in the game" Marines and the Hellcats by the Navy, one would expect those less brave/daring/comitted Navy pilots to escape in their Hellcats with far fewer hits per sortie under the same conditions in comparable operations. No?

Let's take the Marines out of it entirely and focus just on those less brave/daring/comitted men in the Navy. Let's also disregard 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" too as that's just a bunch of malarky designed to confuse us and lead us astray from Corsair worship.


For the entire war, in all operations, Navy carrier pilots lost Hellcats to AA fire at a rate of 1 per 116 sorties.

For the entire war, in all operations, Navy carrier pilots lost Corsairs to AA fire at a rate of 1 per 70 sorties. 66% higher loss rate for Corsair.

For the entire war, in all operations, Navy land based pilots lost Hellcats to AA fire at a rate of 1 per 309 sorties.

For the entire war, in all operations, Navy land based pilots lost Corsairs to AA fire at a rate of 1 per 254 sorties. 22% higher loss rate for Corsair.


Perhaps the less brave/daring/comitted men in the Navy just felt more like Marines when flying Corsairs and pressed their attacks in close in order to achieve more accuracy. Or, maybe there really was very large disparity in survivability between the Hellcat and Corsair, as the authors of the report have pointed out, that may have been related to an oil cooler design that is very different than the Hellcat and Thunderbolt. Maybe the authors of the report, who had access to the data, understood it as well as how and under what circumstances it was collected and obviously knew of the tough, brave reputation of the Marines got it right. The authors took note of the very large disparity between Hellcat and Corsair loss rates under apples to apples circumstances and chalked it up to the Hellcat's greater ability to survive combat damage.

I see no mention of the facts now entered into evidence by Renrich to attack the Report's conclusions and there are many areas in the report where it comments on facts that account for disparities in the data that on their face, may seem odd.

For instance, on the reasons why carrier borne fighters were far more successful in air combat than ground based aircraft:

"The ruling factor here was the mobility of the carrier forces, their
ability to penetrate deep into enemy territory, concentrating. overwhelming force in surprise
strokes against large sectors of the enemy's secondary air defenses. Land-based aircraft, on
the other hand, were seldom within reach of main concentrations of enemy air strength, except
for a time at Rabaul, where the heavy defenses precluded successful attack on grounded aircraft."


And the report didn't shy away from heaping praise on the Marines either:

"The Marine dive and torpedo bonber force, building up from small beginnings to a substantial
striking power, was the backbone of the anti-shipping and tactical striking force in
the Solomons, contributed greatly to the reduction of the Jap bases in the Marshalls, and later
contributed the bulk of its strength to give tactical air support in the reconquest of Luzon
and the southern Philippines. During late 1942 and early 1943 its few planes were devoted mainly
to stopping Jap naval and transport vessels from reinforcing Guadalcanal. Later it carried
its anti-shipping strikes to Bougainville, and in early 1944 cleaned the last Jap ships out of
Rabaul. Meanwhile as its force expanded it built up its attacks on nearby airfields (Munda and
Vila), gave heavy direct support in the New Georgia and Bougainville campaigns, and made the most
accurate and effective attacks in the campaign for destruction of the Jap base at Rabaul. In
March and April 1944 it was a major factor in turning back the Jap counter attacks on Bougainville,
doubling its previous volume of activity, then returned to neutralization of the entire Bismarck
area. In late 1944 the Marine SBDS were largely withdrawn from the Bismarcks area for transfer
to Luzon, where they began their biggest, though not their most important, job of the war."

 

[MikeGazdik]

Which book? Ace of the Eighth by Fortier?

Yes sir. I enjoyed the book everytime I read it.

And on to the argument of Corsair vs Hellcat. I don't have a doubt that the Corsair was more likely to be critically damaged than the Hellcat. And I didn't mean to send this thread off into another direction by my Hellcat comment.

I know Vmax isn't everything, but it is something. And I think it would matter when fighting the faster Luftwaffe planes. The Hellcat had the speed advantage against most of its Japanese adversaries, but it would lose that from its bag of tricks if used in Europe.

 

[lesofprimus]

All this talk on one document concerning the Hellcats survivability vs the Corairs got me thinking about one specific bit of info again and again:

Pilot protection....

All during the discussion, the info states "the F6F had a far lower rate of loss per plane hit." Could there be some disparity because many of the Corsair pilots were getting hit as opposed to a less number of Navy guys in their Hellcats, possibly due to their attempt to get closer and deliver the ordinance on target with a higher probability???

The Corsair was also a larger target for enemy gunners to aim at... I wonder which aircraft had the higher attack speed when delivering munitions..... I would assume the Hellcat was faster going into the attack, which would have made it harder to hit and easier to survive in during ground attack duties...

Which plane had more armor protection for the pilot???

There are too many variables involved in such a comlicated comparison to just say the oil coolers were the reason.... Some very not-to-bright guys in the Navy came to this very abrupt conclusion Im sure....

Which plexiglass canopy protected the pilot better???

Which headrest deflected shrapnel more effectivly???

Also, if the planes were brought down by enemy ground units, they usually crashed in enemy held territory and were thus unavailable to US investigation as to why they went down, oil cooler/pilot trauma or whatever reason... Too many variables involved for me too make this decision soley based on loss ratios....

Great discussion none the less fellas...

 

[JoeB]

Oil cooler arrangement was the general supposition for why the F4U had a higher loss rate than other radial a/c against ground fire. It's true that that's not clearly proven as the reason, while the F4U's higher AA loss rate in similar conditions is pretty clearly proven. But if you look again at NASC, the FM's loss rate to AA in '45 carrier operations was similar to the F6F's, the F4U's rate was high, not the F6F's especially low. Similarly in Korea the comparison was the much higher loss rate of F4U-4 to AA compared to the AD, either of USN units on carriers or of USMC landbased units (which both operated both types). The AD was quite a bit larger plane than either F6F or F4U, FM quite a bit smaller, but the general picture isn't one of size directly determining AA loss rate, but rather the F4U sticking up above other naval radials in AA loss rate. So it does make more sense to look for particular features of the F4U as the explanation, rather than particular features of the F6F.

As Davidicus said, the result is not dependent on considering USMC v USN units. I'd add that the same is true for the operational loss rate comparison in 1945, that of USMC F4U units flying from CV's was only slightly higher than for USN F4U units flying from CV's, but both were around 50 % higher than the F6F's rate from CV's: clearly the plane not the pilots. USN and USMC pilots of late WWII were similarly trained, so it would be surprising if they had much different results in the same a/c in the same conditions, and so not surprising there's little evidence of that.

Joe

 

[drgondog]

Yes sir. I enjoyed the book everytime I read it.

QUOTE]

Bud just passed away in late 2005. He was a very good friend of my father and was very complimentary of dad in the book.

Bud got his only score in a P-47 in the last mission he flew in a P-47 on March 6.. all the rest were in 51's.

Bud also was one of several pilots in the 355th that 'wrung out a D-9 in rat races with 51's while at Gablingen at the end of his tour. He and dad came home together

 

[drgondog]

All this talk on one document concerning the Hellcats survivability vs the Corairs got me thinking about one specific bit of info again and again:

Pilot protection....

All during the discussion, the info states "the F6F had a far lower rate of loss per plane hit." Could there be some disparity because many of the Corsair pilots were getting hit as opposed to a less number of Navy guys in their Hellcats, possibly due to their attempt to get closer and deliver the ordinance on target with a higher probability???

The Corsair was also a larger target for enemy gunners to aim at... I wonder which aircraft had the higher attack speed when delivering munitions..... I would assume the Hellcat was faster going into the attack, which would have made it harder to hit and easier to survive in during ground attack duties...

Which plane had more armor protection for the pilot???

There are too many variables involved in such a comlicated comparison to just say the oil coolers were the reason.... Some very not-to-bright guys in the Navy came to this very abrupt conclusion Im sure....

Which plexiglass canopy protected the pilot better???

Which headrest deflected shrapnel more effectivly???

Also, if the planes were brought down by enemy ground units, they usually crashed in enemy held territory and were thus unavailable to US investigation as to why they went down, oil cooler/pilot trauma or whatever reason... Too many variables involved for me too make this decision soley based on loss ratios....

Great discussion none the less fellas...

These are very good questions - which have also given me pause. The F4U (and Mustangs) were down in the dirt both in WWII and Korea. I KNOW the Mustang had to be more vulnerable to ground fire but the number of aircraft destroyed per loss was almost double the Jug and more than that vs Lightning - which says nothing until you can parse the number of low level sorties of aircraft attacking an airfield.

Ditto the F4U vs F6F. I suppose the USN may have had some sense of the mission profiles but it would be interesting for example to look at losses at Okinawa where the AA was heavy and the fighters were at very low level. Were more F6F's flying CAP for the fleet while the Corsairs were getting singed on the deck?

JoeB - do you know?