F4U in Europe

[nuuumannn]

Actually, most of it was made of wood. The pilot's station is heavily armoured.

Only the rear fuselage and fin was made of wood - birch shpon, as the Soviets called it, laminated sheets, the wings and hori stab were light aluminium, while the fuselage and nose cowl panels was made of armoured steel. The aircraft was quite an engineering challenge for Ilyushin and the first prototype was a non-flying engineering mock-up with the intent of proving its structural elements, the issues with aligning the armour plating in sections with each other were considerable, particularly with misaligned fastening holes.

AB-1 (Aviatsiyonaya Bronya) armour plating was used, which was nickel/monel steel alloy, which had to be formed to shape in the manufacturing process before hardening took place, after which it was difficult to cut or shape, hence doing it while it was soft. The armoured body was known as the bronyekorpus, literally armoured body and was difficult to make, also because of the scarcity of alloying materials in the wartime Soviet Union, although that didn't stop them producing a shed ton of them. The nose armoured panels were 4mm around the front and 5 mm on the lower sides and underside, with a 7 mm slab behind the gunner. Rivets were 5 to 6 mm steel, which was difficult to form, requiring powerful guns - forming steel rivets take practise, it has to be done in one hit, unlike ali rivets that can be "touched" to finely shape the tail with the bucking bar. The weight of armoured panels on the Il-2 was around 700 kg and the top of the nose cowl was made from ali sheet.

These are pictures of Il-10s, which were not far removed from the Il-2 in structure, located in the derelict aircraft park of the China aviation museum, which at the time I took these photos was out of bounds to the public, even more so now as the perimeter fence has been fixed. In the Il-10 the underside nose cowl panel is over a centimetre in thickness. I got this pointed out to me whilst visiting the MLP in Cracow, the guide kindly opened it up for me.

DSC_6018

The difference between the Il-2 and Il-10 being that the rear fuse and fin are made of metal. Note the massive plate behind the pilot's head.

DSC_6028

The armoured cockpit section was hand rivetted as can be seen here, note the sheet ali structure making up the framework for the clear sections, the thickness of the foremost flat plate being gauged by the interior framework.

DSC_6057

In this picture you can see the disposition of steel armour and aluminium.

DSC_6059

 

[33k in the air]

The AAF definition for Combat Radius includes Warm Up, Taxi/Takeoff, Climb to Cruise at Normal Power , Cruise at 210IAS at 25,000 feet, Drop Externals for Engagement, 5 Minutes Combat Power, 15 Min Military Power, Cruise to Descent at 210IAS, Descend and have 30 minutes reserve at Minimum Power.

And the USN methodology for combat radius was:

20 minutes of warm up and idling; one minute for takeoff, 10 minutes for rendezvous at 60% normal power at sea level; climb to 15,000 feet at 60% normal power; cruising to objective at 15,000 feet at optimum cruising; 20 minutes of combat at 15,000 feet at full power; return to base at 1.500 feet at optimum cruising; and reserve of 60 minutes at optimum cruising. Radius includes distance covered in climb but not in descent.

Obviously, very different methodology than that used by the USAAF. Consequently, any figures published by each service are not directly comparable.

The document in question apparently recalculated the radius of the Army fighters using the Navy methodology. I don't remember where I found it; it was probably during a general internet search for aircraft radius/performance information. I've attached a screenshot of the relevant page below (the quality of the source document is not great). Of interest here is the final line of the table, and its accompanying note.

 

[special ed]

Hello Nuuumannn
What is the jet next to the first Il-10?

 

[nuuumannn]

What is the jet next to the first Il-10?

I was wondering if anyone would pick up on that, hey special ed, it's a Nanchang CJ-6 that has been modified with a jet nose to represent a US fighter for a movie. There was once quite a bit of curiosity online about it several years back.

DSC_6019

DSC_6025

 

[Conslaw]

Not once 20 or 30mm cannon shells start flying.

Also I think the Korean War bears a quick examination, both the Mustang and Corsair were flying CAS over the same ground for the same amount of time, here are the numbers as best as I can recall, drgondog I think has the exact numbers:

F-51 341 lost to enemy action, 474 total (accidents etc. incl.)

F4U 325 lost to enemy action (Navy + Marines) 494 total (accidents etc. incl.)

Not sure the F4U stood up to ground fire any better. Math not my strong suit but I believe that's a less than 1% difference in lost to enemy action, I could be wrong on that though.

I had seen those statistics before of the loss rate of F-51 and F4U being effectively the same. I also read something about the oil cooler for the F4U being a weak spot. Does that account for the loss rates being the same? I don't know. Was there a difference in missions? I don't know. I think the numbers speak for themselves for the point that the F4U was not exceptionally damage resistant in ground attack missions. On balance the jets had lower loss rates, probably because they were harder to hit. Were they less accurate? I don't know.

 

[GregP]

Hello Ovod,

Though the USSR DID get a few P-47s (195 to be exact), they didn't operate Typhoons at all or P-47s widely at all in any ground support role. They built 36,000 Il-2s. Pretty easy to see which one was more important to the Soviet war effort. The Il-2 took small arms fire MUCH better than either the Typhoon or the P-47 since it was armored especially from ground fire. We tend to downplay the Soviet WWII aviation today but, without them, the war might VERY easily have gone the other way.

It's easy to say the late-war Il-2, La-5FN / La-7, Yaks, etc, weren't as good as our late model aircraft. It's not so easy when you are facing many hundred of them armed and on the attack. Early in the war, Soviet aircraft were shot down in droves by the Germans. Not quite so in late 1944 / 1945. They were competing on an equal or better basis by then. It is useful to remember who got to Berlin first. It was the Soviets, behind their armor and aircraft who got there first, not the US/UK.

 

[nuuumannn]

It was the Soviets, behind their armor and aircraft who got there first, not the US/UK.

To be fair, the Soviets had a head start and the deprivations the Nazis imposed on occupied populations, not to mention the the Soviet government's particular means of motivation provided unique and persuasive incentive to get to Berlin first.

 

[NevadaK]

To be fair, the Soviets had a head start and the deprivations the Nazis imposed on occupied populations, not to mention the the Soviet government's particular means of motivation provided unique and persuasive incentive to get to Berlin first.

The Russians and Western Allies were roughly the same distance from Berlin in June 1944. Operation Overlord is around 1100km and Kiev/Operation Bagration is around 1300km. Not a head start

 

[GrauGeist]

Eisenhower diverted the units in a way that allowed the Soviets to reach Berlin first, while creating a solid line to the north and south-east.
The U.S. Army advanced to the Elbe and stood down for 11 days, close enough to hear the battle raging in Berlin.

I suspect that they were following the idea of the Yalta conference, which predermined that the Soviets would have the eastern part of Germany and Berlin.

 

[GregP]

The U.S.A. had about 407,000 killed in WWII plus 12,000 civilians. The UK had about 384,000 military and 67,000 civilian. Germany had about 4 - 5M military and 1 - 3M civilians killed.

The USSR had about 9 - 11M military and 4.5 - 10M civilians killed.

That's 22 times the U.S. military deaths and 500 times the U.S. civilian deaths.

I'm pretty sure the Soviets were going to get to Berlin first no matter what. They certainly had the motivation.

 

[drgondog]

And the USN methodology for combat radius was:

20 minutes of warm up and idling; one minute for takeoff, 10 minutes for rendezvous at 60% normal power at sea level; climb to 15,000 feet at 60% normal power; cruising to objective at 15,000 feet at optimum cruising; 20 minutes of combat at 15,000 feet at full power; return to base at 1.500 feet at optimum cruising; and reserve of 60 minutes at optimum cruising. Radius includes distance covered in climb but not in descent.

Obviously, very different methodology than that used by the USAAF. Consequently, any figures published by each service are not directly comparable.

The document in question apparently recalculated the radius of the Army fighters using the Navy methodology. I don't remember where I found it; it was probably during a general internet search for aircraft radius/performance information. I've attached a screenshot of the relevant page below (the quality of the source document is not great). Of interest here is the final line of the table, and its accompanying note.

View attachment 651741

Clearly 1943 chart as USN perhaps didn't have Inteeligence reports on their rival AAF fighters. P-51B in Jan 1944 had 269 gal internal fuel and P-38J had 410 gal. Actually production release for P-47D-25 with 370 gal also occurred in Jan 1944.

 

[tomo pauk]

I also read something about the oil cooler for the F4U being a weak spot. Does that account for the loss rates being the same?

On this tidbit.
Vought re-did the oil cooler system, from two in the wings into one bigger in the low fuselage behind/beneath the engine on the AU-1, while also providing the belly armor. Fresh air was taken from the 'lip' intake.
Grumman did the similar thing for the F8F, just here the fresh air was taken by wing intakes and 'sent' to the oil cooler via piping. The F7F have had the 'S' piping, so the oil coolers can be protected by armor from frontal and rear arc fire.

The vulnerability of oil system was probably taken seriously some time in mid/late ww2 by some US companies.

 

[GrauGeist]

The U.S.A. had about 407,000 killed in WWII plus 12,000 civilians. The UK had about 384,000 military and 67,000 civilian. Germany had about 4 - 5M military and 1 - 3M civilians killed.

The USSR had about 9 - 11M military and 4.5 - 10M civilians killed.

That's 22 times the U.S. military deaths and 500 times the U.S. civilian deaths.

I'm pretty sure the Soviets were going to get to Berlin first no matter what. They certainly had the motivation.

The U.S. 9th Army reached the Elbe before the Red Army reached the Oder.

Eisenhower ordered the stand down for several reasons, one of which was he didn't want American and Soviet troops mixed up in the street fighting, he also felt that Berlin was a political objective, not a tactical objective.

He made the agreement with Stalin personally, and infuriated Churchill in the process.

Here is a good source from a war correspondent who was there and explains in detail why Eisenhower ordered the stand down at the Elbe:
Why Eisenhower Halted at the Elbe

 

[DarrenW]

According to a couple sources the Corsair was able to carry up to 4,000 lbs of ordinance versus 2,000 lbs for the Thunderbolt

The 4000 lb load was not practical for most tactical situations as it would limit range considerably (no centerline drop tank could be carried). Heaviest practical loadout was two 1,000 lb bombs on wing hard points which was identical to the P-47D with a centerline tank. Maximum load out for a P-47D was actually 2,500 lbs which consisted of two 1,000 lbs on wing hard points + 500 lb bomb on centerline rack.

Post in thread 'Largest bomb load of a WWII fighter?' Largest bomb load of a WWII fighter?

 

[nuuumannn]

The Russians and Western Allies were roughly the same distance from Berlin in June 1944. Operation Overlord is around 1100km and Kiev/Operation Bagration is around 1300km. Not a head start

They started heading for Berlin from halting the German advance a lot sooner than 1944. Very much a head start and, like I said, they had extra motivation, so naturally they were going to get there first. The Allies were halted in their advance along the way on a few occasions, too, so shall we go into that, too?

 

[NevadaK]

They started heading for Berlin from halting the German advance a lot sooner than 1944. Very much a head start and, like I said, they had extra motivation, so naturally they were going to get there first. The Allies were halted in their advance along the way on a few occasions, too, so shall we go into that, too?

The point I was trying to make is that in June 1944 the eastern front was actually further from Berlin than the western front.

 

[pbehn]

I remember a long and drawn out discussion where someone asserted that the P-39 could have been used as an escort from UK.

 

[GregP]

Is that when they invented air-to-air refueling?

 

[nuuumannn]

The point I was trying to make is that in June 1944 the eastern front was actually further from Berlin than the western front.

Does it matter? The Soviets still began their advance toward Germany before the Normandy landings, and they had greater motivation for doing so, which was the main point I was making - that their reasoning for doing so was a little more urgent than the Allies.

 

[P-39 Expert]

There wasn't much point in putting more than 250 gallons of fuel internally in the F6F. With the 250 internal and 150 external, the F6F could match the combat radius of a loaded TBF/TBM Avenger, so if you can match the radius of your longest-legged strike plane, everything after that is diminishing marginal returns. On one mission in the Battle of the Philippine Sea, the Americans located the Japanese fleet at the edge of the combat radius of the US planes. The Japanese were fleeing, and flight operations into the wind caused the American fleet to largely go the opposite way. The US launched only F6F, each with a bomb and a drop-tank, to attack the Japanese force partially because the higher cruising speed of the fighters meant they could reach the Japanese force quicker, before they could get farther away, as every mile they gained at 30 knots was going to mean two that the American planes had to fly round trip.

The F4U (without the unprotected wing tanks) had just a bit less internal fuel than the F6F, but as we discussed earlier, the Navy at least had the intention to use external tanks for the F4U that did not have to be dropped in combat. We were not able to determine whether these tanks were actually used and to what extent. The same dynamic applies to the F4U though as the F6F.

Curiously it appears that the F4U was introduced into combat (Feb 1943) with no provision for external stores, similar to the P-47. AHT says that the Navy accepted the first Corsair with an external drop tank fitting in October 1943 after over 1300 had been produced. Jerry rigged mounts had been produced at forward bases, but no factory mounts until October 1943.