Army Air Force F4U Corsair

Shortround6 said:

With out drop tanks the fighters had no hope of escorting the bombers all the way to the target. Even with drop tanks most WW II fighters could not match the range of the bombers. This is one reason the long range escort mission was not a high priority at the beginning of the war.
One of my favorite examples is the RAF bombing Genoa Italy using Whitley bombers in 1940. Granted it was done at night with a bomber that had no hope of surviving in daylight but I believe the straight line distance from Brighton to Genoa is 612 miles one way. There were few (if any) 1000-1200hp fighters in 1940 even with drop tanks that could attempt such a flight. This is one of the reasons for some of the twin engine fighters of the late 30s. They were willing to sacrifice some performance in return for longer range. There was no way a 1000-1200hp fighter could be built to have the same range as a B-17 or B-24. The B-17C ordered in 1939 was supposed have a range of 2400miles with 4,000lb bomb load. You could make a single engine plane with about the same range but it would useless as a fighter at any range.

Once more powerful engines became available (for little more weight) or very powerful engines became available for more weight the possibility for long range fighters became much greater.

Even if you had a forward thinker who didn't believe "the bomber will always get through" the long range escort fighter was a technical impossibility in 1939-40. It would not be in another 4 years but it needed better aerodynamics, better engines and better fuel. Better fuel allowed for higher cruise power settings (or higher compression/ more fuel efficient engines) and/or more take-off power for little more weight.

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Resp:
Actually, the A6M Zero could fly well over 1,000 miles with one drop tank in 1940. Gen Chennault sent a detailed report to either Gen Marshall in late 1940 or early 1941, which covered the fighter's range. He saw that it was written by Chennault, and tossed it in a drawer . . . never to be seen. Chennault traveled to Hawaii in mid 1941 to give a 3 hrs lecture on the Zero to AAF pilots (not sure if any Navy pilots attended). Since 1939, the USAAC had a restriction against manufacturers incorporating plumbing for external fuel stores on fighters destined for their service. The USAAF test pilot assigned to Lockheed convinced the engineers to make the P-38 drop tank capable, even though the contract forbid it. They were coming off the production line at the time of Pearl Harbor. Thank God.

You are forgetting about the turbo-charger in the P-47. In mid 1943 the P-47 had 2000hp available at all altitudes up to and exceeding 25,000ft . At 25,000ft the F4U-1 was down to about 1525hp (including ram) and was about 30mph slower than the P-47, it also wasn't climbing as well. (Neither plane using water injection)
There is a difference between climbing/flying and formation flying at 30,000ft and fighting at 30,000ft. The P-47 is going to be able to maintain height better than the Corsair even though both are descending if maneuvering hard. The P-47 just might not have to descend as much and may be able to get back into position quicker. The Corsair may very well have an advantage over the FW 190 but then the P-47 should have the advantage over the FW 190 to at higher altitudes.
When it comes to high speed cruise the turbo was like free horsepower. It could get the manifold pressure up to what was desired without taking much away from the engine. (it did take something, it was not 100% free) while the F4U was caught somewhere between low gear and high gear on the auxiliary supercharger depending on exact cruising speed and altitude desired. It took around 350hp to run the supercharger at full throttle, much less at cruise power settings but still much more than the turbo cost the P-47 in terms of higher back pressure.

The F4U wing tanks were integral tanks, the Leading edge/top/bottom formed the front/top and bottom of the tank/s with the main spar forming the rear and the ribs forming the ends and/or internal baffles. There is no "separate tank" to take out and drop a new tank in it's place. You have to take that section of the wing apart, apply sealant and/or squeeze bladder cells into the spaces and then rivet (or weld?) everything back together. Please note that some other US planes using integral tanks suffered from fuel leaks even without combat damage (P-43s).
Probably much easier to do in the factory than in the field.
Also please note that one of the things that gave the P-38s so much trouble was that some of them were being flown at over 30,000. All the escort fighters did not fly at the same altitude, some flew higher to prevent the Germans form bouncing from above.
Both the British and the Germans were flying at least some fighters at 30,000ft or slightly above during the BoB.

The P-38 only had trouble at 30,000 feet until they worked out the fuel, intake mixture (turbulator inside the manifold), and gave them electric cockpit / gun heaters. After that, they had no trouble at 30,000 feet in the ETO or anywhere else, aside from the well-known low critical mach number. I'm thinking of the P-38J-25 and onward. Any P-38F or earlier might still have had uncorrected high-altitude issues. The H and early Js ... probably not, depending on where they were in the modification process.

Good post above, Shortround.

GregP said:

The P-38 only had trouble at 30,000 feet until they worked out the fuel, intake mixture (turbulator inside the manifold), and gave them electric cockpit / gun heaters. After that, they had no trouble at 30,000 feet in the ETO or anywhere else, aside from the well-known low critical mach number. I'm thinking of the P-38J-25 and onward. Any P-38F or earlier might still have had uncorrected high-altitude issues. The H and early Js ... probably not, depending on where they were in the modification process.

Good post above, Shortround.

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Resp:
The report I read, written by a Squ Commander in the ETO, stated that they had trouble w the P-38 at 20,000 and higher.

fubar57 said:

Der Gabelschwanz Teufel - Assessing the Lockheed P-38 Lightning

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Resp:
Der Gabelschwanz Teufel is the best analysis of the P-38 that I have read (found it last yr).

Shortround6 said:

I believe a some/large number of the Goodyear produced F4U aircraft were not only "hook-less" but had non-folding wings as well.

From the Vought Heritage web site: vought heritage


"Goodyear's version was designated FG-1. In 1943, Goodyear delivered 377 FG-1's. In 1944, Goodyear boosted the production rate six-fold to 2,108 aircraft. Another 1,521 FG-1's were accepted in the 8 months of hostilities during 1945 for a wartime total of 4,006 aircraft. This amounted to over one-third of all Corsairs produced during World War II. Many of these FG-1's were built with non-folding wings during the period before Corsairs were put aboard carriers, and these aircraft went to land-based Marine squadrons."

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Resp:
Two questions:
1. Which aircraft mfg built the non-folding wing version of the Corsair, and
2. How much weight was saved by doing so?

USN did try out a turbocharged Corsair, the F4U-3. The quasi modern dictum by Milton Friedman "there are no free lunches" also applied to aircraft design n WWII. The Navy was interested an aircraft that preformed best below 25,000' and the turbo added weight and complexity that was less effective at Pacific combat altitudes.

Navalwarrior said:

Resp:
Two questions:
1. Which aircraft mfg built the non-folding wing version of the Corsair, and
2. How much weight was saved by doing so?

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All Corsairs had folding wings, the ones built by Goodyear (FG-1) simply didn't have the hydraulics fitted, meaning the wings could still be manually folded and not having the mechanism fitted saved roughly 48 pounds.

Navalwarrior said:

Resp:
Two questions:
1. Which aircraft mfg built the non-folding wing version of the Corsair, and
2. How much weight was saved by doing so?

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Of the 4,007 Corsairs delivered by Goodyear, 965 (almost one-fourth) were delivered without folding wings. There were also kits and field instructions to remove the folding mechanism and other weight-saving features from other Corsairs, regardless of the manufacturer. The total weight saved by removing the folding mechanism and tail hook was estimated at 94 pounds, though this was later downgraded to 80 pounds. The aircraft was to average an increased top speed of 4 mph.

The wings could be folded manually - but the wing fold seams were taped, puttied, and smoothed, so one fold would ruin the job. As the attached photo shows, Some Corsairs even carried a "Wings Won't Fold" warning while being transported on carriers.

All the folding mechanism would be reinstalled in about four hours, but with the advent of the FG-1D and the Marines' return to carriers with the newer models, I'm not sure any FG-1As were retrofitted.



One sign that a Corsair was probably a fixed-wing version was the modification of the tail wheel doors. All Corsairs had two doors on each side; when the hook was removed, the after halves of the doors were bolted closed and the cove for the tail hook was skinned over. Here's an example:




Cheers,



Dana

Dana Bell said:

Of the 4,007 Corsairs delivered by Goodyear, 965 (almost one-fourth) were delivered without folding wings. There were also kits and field instructions to remove the folding mechanism and other weight-saving features from other Corsairs, regardless of the manufacturer. The total weight saved by removing the folding mechanism and tail hook was estimated at 94 pounds, though this was later downgraded to 80 pounds. The aircraft was to average an increased top speed of 4 mph.

The wings could be folded manually - but the wing fold seams were taped, puttied, and smoothed, so one fold would ruin the job. As the attached photo shows, Some Corsairs even carried a "Wings Won't Fold" warning while being transported on carriers.

All the folding mechanism would be reinstalled in about four hours, but with the advent of the FG-1D and the Marines' return to carriers with the newer models, I'm not sure any FG-1As were retrofitted.

View attachment 539902

One sign that a Corsair was probably a fixed-wing version was the modification of the tail wheel doors. All Corsairs had two doors on each side; when the hook was removed, the after halves of the doors were bolted closed and the cove for the tail hook was skinned over. Here's an example:

View attachment 539903


Cheers,



Dana

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Resp:
The photo of the damaged Corsair also shows a good view of the Brewster Bomb Rack.

Of the 10 FG-2's built, five were without folding wings or tail hooks. I expect that the taped wings added a couple knots. I remember seeing a test sheet on the Corsair giving drag speed reductions for all sorts of minor exterior things. Bigger ones were the tailwheel doors and the walkway on the wing.