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

[Jank]

Let's not forget that the P-47 also had a full 1/3 more firepower as well. That's not insignificant.

Think of it this way. Imagine two cruisers having single turrets both fore and aft. One cruiser has turrets housing three 5" guns for six guns total. The other cruiser is outfitted with turrets that have four 5" guns for a total of eight.

Which cruiser would you rather take a broadside by?

 

[Jank]

"This was the 4th fighter group and some of the 4th pilots refused to fly the P47. "There are crashes, dead stick landings, mid-air fires, bailouts and gear collapses on the runway. Some pilots die in operational accidents."

I don't recall the Jug getting pegged with a nickname equivalent to "ensign eliminator" which, by the way, was not specific to carrier operations.

"Nazi eliminator" perhaps.

Even with it's enormous size and weight, the P-47 managed to rack up a 4.6:1 air to air kill record against a foe that understood marshalling tactics on a group level. (as opposed to the foe that Corsair pilots faced) Moreover, that record was established, for the most part, before the Thunderbolt saw its role shifted to ground attack and thus was during a period when the Germans weren't far outnumbered by American fighters as was the general situation with the P-51. Thunderbolt pilots commonly found themselves outnumbered by their adversary.

 

[davparlr]

I would like to see backup on P47B operations in Oct. 42. My data shows the first operational mission was on March 10, 1943. 14 P47s and 12 Spits over France. This was the 4th fighter group and some of the 4th pilots refused to fly the P47. "There are crashes, dead stick landings, mid-air fires, bailouts and gear collapses on the runway. Some pilots die in operational accidents. On this first sweep radio interference problems are encountered. Plane to plane communication is impossible." The first official operation with the 8th air force is on April 8, 1943. The Corsair's first operational mission was on Fe. 14, 1943.

My data shows the P-47B production units starting to appear in March of 42 and deliveries were made to the fighter group in June, 1942, and production P-47Cs starting in Sept. 42. I also have data that shows P-47Cs arriving in Europe in late 42, and having their first major combat in April, 43. I have no data on the operations of the P-47B.

Classic Military Warnings

"Aim towards the enemy" - Instructions printed on U.S. Army Rocket Launcher

 

[davparlr]

Max Speed at S/L - 353mph (Corsair) 340 mph (Thunderbolt)

Max Speed at 20,000ft. - 405mph (Corsair) 415 mph (Thunderbolt)

Flight test data I have seen from SpitfirePerformance for late P-47D (Tail No. looks like 42-26167)/F4U-1 (Tail Number looks like 13978) has:

Max Speed at S/L - 365 mph (Corsair) 347 mph (Thunderbolt)

Max Speed at 20k ft - 430 mph (Corsair) 437 mph (Thunderbolt)

Classic Military Warnings

"When the pin is pulled, Mr. Grenade is not our friend" - U.S.M.C. training.

 

[Jank]

Do you have a link? There'a a lot of data on that site.

 

[Jank]

I see it now. That P-47D clocked 444mph at 23,200ft and had a climb rate of 3,260fpm at 10,000ft. Moreover, it was still pulling 3,000fpm at 20,000ft!

It was with 44-1 fuel.

Do you have a link to the specific test for the F4U-1?

 

[Jank]

I see data for a late war F4U-1 No. 17930 (you mentioned 1397) in 1944 with water injection.

http://www.wwiiaircraftperformance.org/f4u/f4u-1-17930.pdf

S/L Top speed 365mph
20,000ft Top Speed 430mph
Top Speed 431mph @ 21,000ft

Maximum climb at S/L 3,210fpm

They installed a new, more efficient propeller and the report stated that, "The above difference in performance is attributable partly to the better efficiency of the new propeller ... and modified cowl flap arrangement."

It was a test of and report on improvements not existing on a production Corsair and the P-47D test, while a production stock aircraft, was with special fuel. 44-1 is the 100/150 grade fuel. I do not know if it saw use as it fouled up the Mustangs pretty bad.

 

[Jank]

It appears that the 44-1 fuel was in fact employed by Thunderbolts after all.

From: 150 Grade Fuel

In late Winter 1944 the Allied Expeditionary Air Force (A.E.A.F.) decided, pending further trials, not to employ 150 Grade Fuel for Overlord due to spark plug issues, however, it was intended that 150 Grade would be used when proved satisfactory. 17 Meanwhile, cross channel operations by two squadrons of P-47's and one P-38 using 150 Grade fuel revealed an increase of speed and climb characteristics at the expense of spark plug difficulties. 18 The Production Division was directed on 28 March 1944, under the authority of the Commmanding General, Army Air Forces, to modify all P-38, P-47 and P-51 airplanes in the United Kingdom for the use of Grade 150 fuel, with the necessary modification kits to be shipped to the European Theater of Operations within 30 days. 19

Successful service tests led in May 1944 to the Eighth Air Force Fighter Command requesting that it "be supplied immediately with grade 150 aviation fuel for use in P-47, P-51 and P-38 planes". 20 Deliveries of Grade 100/150 aviation fuel to AAF Stations commenced within a week of the landings in France. 21, 22 The change over to 150 grade fuel necessitated the resetting of all aneroid switches on the P-51s.

...

150 grade fuel continued to be used by 8th AF units through 1944. 24 The WER engine limitation for the P-51 continued to be 72" Hg. 25 Eighth Air Force Fighter Groups converted to a new blend of 150 grade fuel, with increased amounts of ethylene dibromide (1½ T) in early 1945. 26 P.E.P, as the new fuel was called, was tried in order to remedy lead fouling of spark plugs. While spark plug fouling was eliminated, PEP was found to have an undesirable effect on valve seats. As a result of excessive maintenance required on the V-1650 engines, General Doolittle of the Eighth Air Force decided in late March 1945 to revert to the normal 100/150 (1 T) grade fuel. 27

...

Technical Operations, Eighth Air Force issued a 4 April 1945 memorandum in which 100/150 grade fuel experience in the Eighth Air Force was summarized. It is reproduced in full below:

1. The following is a summary of 100/150 grade fuel experience in Eighth Air Force.

2. a. This fuel was first service tested by Technical Operations Section, this headquarters, in October 1943, said service test lasting through until March 1944, at which time it was recommended that if extra performance from P-38, P-47 and P-51 aircraft was desired it could be secured by the use of this fuel. It was pointed out at that time that the only apparent deleterious effect of this fuel on any one of the three types was the extra lead fouling of spark plugs.

b. A decision was made in May 1944 to have all fighter units supplied with this fuel no later than 1 June. As of that date operations with this fuel continued until approximately 1 February 1945 when all fighter units switched to "Pep" (100/150 plus 1.5 T's ethylene dibromide). As of 1 April 1945 all units switched back to 100/150 fuel containing 1.0 T ethylene dibromide.

3. At the time the 150 grade fuel was first used all three fighter types listed above were in operational use by this Air Force. Shortly after June 1 P-38 units were re-equipped with P-51 type aircraft so that experience with 150 grade fuel in P-38 aircraft is limited. Gradually, conversion of P-47 outfits to P-51's took place during the Summer and Fall of 1944, and as of approximately 1 November only one P-47 group remained in this Air Force.

4. Maintenance difficulties can be summarized as follows:

a. P-38 (V-1710 Engine).

Spark plug leading was increased. The extent of this leading was such that plug change was required after approximately 15 hours flying. This conditions was aggravated considerably by low cruising powers used to and from target areas, while trying to get the maximum range possible. It was found, however, that regular periods of high power running for a minute of two in most cases smoothed out any rough running engines unless the cause was other than leading.

b. P-47 (R-2800 Engine).

Spark plug fouling was the only maintenance difficulty encountered during the period in which 150 grade fuel was used. Spark plug life was reduced by about 50%, the same low power cruising as described above being the principle cause for the extra fouling. No deleterious effects on diaphragms, fuel hose or any other rubber of synthetic rubber materials were noted.

c. P-51 (V-1650 Engines).

The same type of lead fouling as described in a and b above happened in the case of the P-51 except that is was probably more serious than in either of the other two types. Using 130 grade fuel with 4½ cc. of lead, the average operational P-51 could last 5 missions (roughly 25 hours) before the fouling required plug change. With 150 grade fuel containing 6 cc. of lead, 10 to 12 hours, or normally 2 missions, was the average length of time between spark plug changes or cleaning. At various times in the six months of operation of P-51 aircraft on 150 grade fuel many other maintenance difficulties were attributed to the fuel, but final analysis proved that the only real effect of the fuel was the lead fouling. Some units maintained that they had some deteriorations of seals, but this was not borne our throughout the command, nor was there any concrete evidence that it existed in the units.

The excessive fouling of spark plugs usually exhibited itself in roughing up of engines after a couple of hours of low power cruising. Periodic bursts of high power in most cases smoothed the engine out. However, if the engine was allowed to go too long a period without being cleaned out, the accumulation of lead bromide globules successfully withstood any attempts to blow them out. In some instances, long periods of idling while waiting for take-off and a failure to use high power on take off resulted in loss of power during take-off run and in some cases caused complete cutting out with subsequent belly landing. The cases of cutting-out on take-off definitely attributed to excessive fouling were comparatively few, although numerous enough to list it as an effect of the extra lead.

As a result of several months operational use with the fuel, an SOP – designed to reduce power failures on take-off, leading troubles in flight, and other things which were causing early returns and abortive aircraft – was published. This is inclosure no. 1. Almost immediately after this section published this SOP practically all of the troubles then existing ceased, although it was necessary to change plugs after each two missions or thereabouts.

In an effort to reduce the lead fouling, tests were conducted by this section with 150 grade fuel containing 1.5 T's of ethylene dibromide. A total of about 120 hours was run by this section and the three squadrons given the "Pep" fuel for accelerated service tests. The results of these service tests showed a considerable reduction in lead fouling with no apparent effects otherwise. As a results, all fighter units of the Air Force were put on Pep fuel late in January 1945. About thirty days thereafter a sharp increase in valve trouble was experienced with the V-1650 engine. Inspection of engines at overhaul revealed that the hydrobromic acid was eroding the silchrome valve seat inserts to such an extent that after approximately 100 hours of operation all the valve clearance was gone. This 100-hours is the minimum life some engines going 170 to 180 hours before this condition prevailed. There are no other deleterious effects of this fuel noted. As of 1 April 1945 fighter units of the Air Force returned to the use of 100/150 grade fuel containing 1.0 T of ethylene dibromide. 28

 

[renrich]

Interesting data on F4Us in ww2: Corsairs shot down 2140 enemy a/c for the loss of 189 Corsairs. Sorties were 64051, 54470 from land bases, 9581 from carriers. Additional F4U losses were 349 from ground fire, 230 from other, 692 on non-operational flights and 164 in crashes on airfields or carriers.

 

[renrich]

Some of the F4U4s were built with 4- 20mm cannon rather than the 6-50s. Their throw weight would be 11.6o lb/sec. The 8-50s of the P47 yielded a throw weight of 12.72 lb/sec. The P47B-N carried 267 rds per gun which gave them a firing time of 17.8 sec. The F4U1-4 carried 400 rds per gun which gave them a firing time of 26.7 sec.

 

[bigZ]

What was the US pilots opinion of using the 20mm cannon on the Corsair? Or was this just for the RN pilots?

Personally I would prefer the cannons even compared to 8-50's on the P47.

 

[renrich]

I don't know but I do know that the early use of the 4-20s on the F4U-1Cs was not met with great enthusiasm. However a lot of the 4s and all othe 5s used in Korea were armed with the cannon. Incidently some of the Hellcat night fighters were armed with 4-50s and 2-20mms.

 

[renrich]

Hope I am not out of order by posting this here but has this group ever discussed who was the greatest fighter pilot of all time. My vote would go to Marseille(hope I spelled his name right.)

 

[Jank]

"Personally I would prefer the cannons even compared to 8-50's on the P47."

The USN conducted tests of the 20mm and .50 and determined that at close range, a 20mm round had 3X the destructive power. This was reduced to 2.5X at longer ranges.

With the ammunition loads carried, the P-47 had more seconds of fire before she went dry compared to a four 20mm package.

At any rate, I think that four 20mm's were probably a superior package although I never heard of a pilot who didn;t think he had tremendous firepower with eight .50's. Pilots often reported their targets disintegrating or just exploding under fire from the approximately 100 round per second stream of armor piercing incendiary ammunition.

 

[Jank]

Renrich said, "The P47B-N carried 267 rds per gun which gave them a firing time of 17.8 sec. The F4U1-4 carried 400 rds per gun which gave them a firing time of 26.7 sec."

Do not confuse what the maximum capacity was as opposed to what might have been carried.

Your "Pilot's Flight Operating Instructions - P-47B, C, D and G", January 20, 1943, states that the capacity is 425 rounds per gun. Page 38C - "The maximum load is 425 rounds each."

Also, note this test data that included F4U-1, -4 and P-47D. Throughout, they indicate full loadings of 2,400 rounds for the six gunned Corsair (400 rpg) and 3,400 rounds (425 rpg) for the Thunderbolt.
http://mywebpages.comcast.net/markw4/MSWF4UDATA.pdf

Did you know that the P-47N was designed to carry bomb loads of 3,700lbs (1,600lbs under each wing and 500lbs under the belly) and the P-47M was designed to carry bomb loads of 4,200lbs (1,600lbs under each wing and 1,000lbs under the belly)? Also, the P-47N had the capacity to carry 500 rounds per gun. 267 "Normal" and an additional 233 rounds in "Overload" condition. (Republic Aviation Performance, Dimensions and Capacities manual for P-47N and M.) Also, see pgs. 56-58 of P-47N Pilot's Manual which states that the maximum ammunition load is 500 rounds per gun.

That's 25% more capacity and a 25% longer firing time than the Corsair (500 rounds as opposed to 400 rounds) coupled with a third more firepower to begin with (eight as opposed to six guns).

Back to the issue of capacity vs. practice, I don't think P-47N's ever did carry 3,700lbs in bombs (1,600lb bombs were not standard but did exist). But just because the P-47N didn't actually carry more than 2,500lbs of bombs didn't therefore set the maximum bomb capacity at that point.

 

[jpatrick62]

jank,

Thanks for posting the link. By those numbers, the F4U-4 has a real hot ship!

 

[renrich]

Charles Lindberg took off and bombed with a Corsair in the Pacific with 2-1000 lb bombs and 1-2000 lb bomb. He also stated that the visibility from the cockpit of an early Corsair was no worse than the visibility from The Spirit of St Louis. There are some interesting stories about Lindberg and his flying of early model Corsairs in WHISTLING DEATH by Boone Guyton. Guyton did much of the test work on the F4U and is responsible for the difficulty that small and short pilots had in the Corsair cockpit. Guyton was 6ft 4in tall. Lindberg had a lot of input and did a lot of flying during the development of the P47 also. It would have been interesting to have gotten his opinion about the merits of the 2 fighters.

 

[Treeseeker300]

Heres some info on the F4U. I found it very informative and in all honesty i think the Corsair was a slightly better plane. =)

Chance Vought F4U-4 Corsair

Since they are both American planes, I would favor either or against an enemy plane any day of the week

 

[DerAdlerIstGelandet]

Since they are both American planes, I would favor either or against an enemy plane any day of the week

Why is that?

There were great British aircraft out there as well let alone great Luftwaffe aircraft as well.

 

[Screaming Eagle]

I agree both sides had some great aircraft, although my favourite fighter is the P-51D Mustang