Hardest plane to take down in WW2?

[FLYBOYJ]

Originally Posted by Magister

FLYBOY,

What is your opinion on fabric vs. aluminum on control surfaces with respect to holding up to heavy machine gun and cannon fire?

When you punch holes in fabric, it will tear, especially at very high speeds (above 250 mph) and especially on a surface where there could be negative aerodynamic pressures (like a control surface). Even if a machine gun or cannon round goes right through fabric covered structure, you'll get the same reults. When the control surface looses enough fabric, it no longer works, you loose control at the axis that control surface "controls."

Metal surfaces, although thin are a lot more resilient. Back in the day metalized control surfaces were made from "24T" aluminum which was really 2024 T3 or T6 depending on the manufacturer. Again, I would believe metalized surfaces would be a hell of a lot more resilient than fabric surfaces unless you had cannon rounds "exploding" on them upon impact, but then again, a well place cannon shell could do the same thing on a fabric covered control surface if the round impacts a more rigid portion of the structure...

[Lunatic]

Originally Posted by FLYBOYJ

When you punch holes in fabric, it will tear, especially at very high speeds (above 250 mph) and especially on a surface where there could be negative aerodynamic pressures (like a control surface). Even if a machine gun or cannon round goes right through fabric covered structure, you'll get the same reults. When the control surface looses enough fabric, it no longer works, you loose control at the axis that control surface "controls."

Metal surfaces, although thin are a lot more resilient. Back in the day metalized control surfaces were made from "24T" aluminum which was really 2024 T3 or T6 depending on the manufacturer. Again, I would believe metalized surfaces would be a hell of a lot more resilient than fabric surfaces unless you had cannon rounds "exploding" on them upon impact, but then again, a well place cannon shell could do the same thing on a fabric covered control surface if the round impacts a more rigid portion of the structure...

Flyboy, this was one of the speific characteristics of the fabric used on the Corsair wing. It would not tear or shred, similar to todays Tyvex, which will not tear or shred until tremendous force is applied. Try it, go buy a Tyvex envelope and punch or cut two holes in it and stick your fingers in and try to tear it. Even though it is paper thin I would bet you cannot tear it.

And again, the ailerons were wood. The rudder was fabric covered, and I'm not positive what the elevators were made of.

[FLYBOYJ]

Originally Posted by Lunatic

Flyboy, this was one of the speific characteristics of the fabric used on the Corsair wing. It would not tear or shred, similar to todays Tyvex, which will not tear or shred until tremendous force is applied. Try it, go buy a Tyvex envelope and punch or cut two holes in it and stick your fingers in and try to tear it. Even though it is paper thin I would bet you cannot tear it.

And again, the ailerons were wood. The rudder was fabric covered, and I'm not positive what the elevators were made of.

My information was about fabric contol surfaces in general. The material used on the Corsair I believe was a polyester or eve dacron, although more resilliant than other fabrics, were still subjected to tearing and ballooning despite claims to the otherwise. It was replaced in later models.

"Until the dash 5, the outer top wing panels and the control surfaces of the Corsair had been fabric covered. At speed, the fabric tended to deform and slow the aircraft by a few miles per hour. The F4U-5 had all fabric surfaces replaced with sheet duralumin to minimize this problem. Armament was the same as the F4U-4."

http://www.aviation-history.com/vought/f4u.html

[FLYBOYJ]

here's a list of synthetic fabics used on aircraft....

Dacron® Registered trade name for polyester fibres made by E.I. DuPont de Nemours & Company. Poly-Fiber® (and all it's other pseudonyms) is Dacron material.
Ceconite® Registered trade name for a fabric woven from polyester fibres and covering process. Application is with nitrate and butyrate dopes.
Stits Fabric Generic name for a fabric covering process developed by Mr. Ray Stits. Purchased by Poly-Fiber Inc in 1993 and renamed Stits Poly-Fiber.
Poly-Fiber®ii Registered trade name for a fabric woven from polyester fibre. A Poly-Fiber Inc material and process. Application is with Poly-Fiber® products.
Razorback® Registered trade name for a glass fibre fabric and covering process.
Superflite® Registered trade name for a fabric woven from polyester fibres and covering process.
Madapolam A bleached cotton fabric with a soft finish used in covering wooden surfaces. Complies with British Standard (BS) F114.

[Lunatic]

Originally Posted by Magister

What I've been saying is that I have been looking for the admission of the AAF for quite some time now and have never found it. I don't think the Corsair can absorb more damage than the P-47 and keep flying.

Also, I don't believe that fabric was chosen because, "It was secifically done to make the plane more resistant to damage despite the fact that it was harder to maintain than dural sheeting." You know better than that Lunatic.

Eventually I'll run across the source for the USAAF/USN evaluations and post it.

Why else would Vought have chosen to cover the wings with fabric. Please note, you keep refering to the covering of control surfaces with fabric. This is NOT what I'm refering to. The entire wing ouside the fold behind the mainspar (about the rear 75%) was covered in fabric.

What other reason could there be? The weight difference is not signficant. The fabric is harder to maintain because it stretches and must be tightened requently and replaced regularly. It is harder to repair and usually must be replaced when damaged. It also has some problems with ballooning at high speeds if not sufficiently tight. The clear reason for its use is to prevent the detonation of cannon rounds, mostly AA cannon rounds, when passing through the wing in this area that has relatively little ribbing or structure.

=S=

Lunatic

[Magister]

It would not tear or shred, similar to todays Tyvex, which will not tear or shred until tremendous force is applied.

I assume we can stipuilate that exploding 2cm shells qualify. When a round penetrates the skin and explodes beneath at a structural piece, the energy tries to escape where it is easiest to do so (like the entry hole) and tears the living s-h-i-t out of it with the help of shrapnel tears throughout the area which explains the many photos I discussed earlier.

One thing is for certain, Vought did not choose to cover the wings with fabric because they thought it would make the plane more vulnerable to enemy fire! Duraluminum was readily available and could easily have been used instead. It was secifically done to make the plane more resistant to damage despite the fact that it was harder to maintain than dural sheeting.

I guess that next you'll argue that since Republic engineers had the same choices in materials, they decided on aluminum because they wanted a plane that would be less resistant to damage.

And I forgot about the wood ailerons. Ever see a piece of wood hit by bullet? Those who have seen bullet impacts through wood will understand. Bullets make much bigger holes in wood than in aluminum.

The rifling in the barrels of all these planes was more often than not badly eroded so that the rounds would start to tumble at longer ranges like beyond 200 yards. (I said start to tumble. It might take another 300 or 400 yards or more to get completely sideways.) They weren't concerned with pinpoint accuracy so this wasn't a problem. Wood performs horribly compared to aluminum especially if a round strikes off center and, of course, I would argue, fabric does as well.

Back to fabric, once you have a big hole and shrapnell tears in the immediate ares and place very high stress on the fabric from hard manuevering at high speeds it just tears more. We have all seen this phenomenon where planes return with flaps of skin hanging open.

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Flyboy, it sounds like when the F4U-5 had all fabric surfaces replaced with sheet duralumin to minimize those problems, it may have been done to specifically make the plane less resistant to damage (assuming the choice of fabric over aluminum was done to make the surface more resistant to damage) per Lunatic's assessment.

Metal surfaces, although thin are a lot more resilient.

I concur whole heartedly.

[Lunatic]

Originally Posted by FLYBOYJ

here's a list of synthetic fabics used on aircraft....

Dacron® Registered trade name for polyester fibres made by E.I. DuPont de Nemours & Company. Poly-Fiber® (and all it's other pseudonyms) is Dacron material.
Ceconite® Registered trade name for a fabric woven from polyester fibres and covering process. Application is with nitrate and butyrate dopes.
Stits Fabric Generic name for a fabric covering process developed by Mr. Ray Stits. Purchased by Poly-Fiber Inc in 1993 and renamed Stits Poly-Fiber.
Poly-Fiber®ii Registered trade name for a fabric woven from polyester fibre. A Poly-Fiber Inc material and process. Application is with Poly-Fiber® products.
Razorback® Registered trade name for a glass fibre fabric and covering process.
Superflite® Registered trade name for a fabric woven from polyester fibres and covering process.
Madapolam A bleached cotton fabric with a soft finish used in covering wooden surfaces. Complies with British Standard (BS) F114.

That's very nice but none of those fabrics are for a WWII Corsair. They are all for civilian aircraft and damage from gunfire is not a serious consideration.

[FLYBOYJ]

Originally Posted by Lunatic

The clear reason for its use is to prevent the detonation of cannon rounds, mostly AA cannon rounds, when passing through the wing in this area that has relatively little ribbing or structure.Lunatic

If the evaluator was a pilot with little or no aircraft maintenance or engineering background, I could see him making that statement.

I believe the reason why the center wing section was fabric on early F4Us were because during high G maneuvers that center section would buckle and wrinkle, an easy solution would be to go with fabric covering. Although aluminum structures were coming into their own in the later 1930s, heat treating technology on aluminum was still coming into its own. A skin stressed aluminum skin that wasn't stress relieved would work harden if placed in an area where there will be various loads, this would result in the skin cracking. By the time the decision was made to replace the fabric with aluminum skin, I would guess that engineers worked out the problem, either by modifying the heat treating process of the skin, or by opening up the tolerance of the fastener holes to accommodate the movement of the skin and structure under stress, something I've seen done on several different aircraft. Here is a cut away of a Corsair - there is plenty of structure in the area where the fabric would be - I'd say it would be pretty lucky for any round to go straight through without hitting anything...

[FLYBOYJ]

Originally Posted by Lunatic

That's very nice but none of those fabrics are for a WWII Corsair. They are all for civilian aircraft and damage from gunfire is not a serious consideration.

The point is similar (earlier) materials were used during WW2....

Canvas? Never!

[Magister]

IMHO, the P-47 appears more structurally sound.

[CurzonDax]

In this discussion I am on the Corsair camp. But the argument I have on this, and I might have missed it is that the Corsair never flew against the Luftwaffe where as the 'Bolt flew both against the Luftwaffe and the IJAF and IJN. I guess I don't really have an argument just an observation unless all are saying that a cannon shell is a cannon shell and that, and I am WAY ignorant on this, that Luftwaffe cannons had more hitting power, more muzzle velocity, and more explosive power than those of the Japanese. So if this be true, and again I am just trying to learn here, wouldn't this be a apples and oranges argument since the Corsair was never under Luftwaffe guns.

So therefore again if this is true, its not whether parts of the wings are fabric or not its what and whose cannon and for that matter machine gun, can do the most damage.

I hope I made sense.

:{)

[FLYBOYJ]

Both were very very robust, but at the same time if you're in either one and you're taking fire, especially air-to-air chances are you're already screwed!!!

[Magister]

The poser of the question knows best but I take it simply as a discussion as to wgich plane could absorbe more damage either by Japanese or German guns.

T-Bolt and Corsair both flew against the Japanese and only the T-Bolt flew against the Germans.

That doesn't mean we can't speculate! Hell, this board is all about speculation and that's the fun of it!

I'm sure the two aircraft are similar in being able to take damage but I come down on the T-Bolt side. (Maybe I'm biased)

All this talk of fabric and wood makes me want to build a tent.

[FLYBOYJ]

Originally Posted by Magister

All this talk of fabric and wood makes me want to build a tent.

Or buy a new dress and a new wooden leg!

[Lunatic]

Originally Posted by Magister

IMHO, the P-47 appears more structurally sound.

How so? (note: vega-aviation-art is long gone from the web)