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[soldaten]

A couple of general questions about WWII aircraft.

Sometimes the airplanes in Sturmovik seem
to have fabric covered control surfaces
(like the rudder) even though
the rest of the fuselage is
metal. If this is the case, why was
fabric retained for the control surfaces?
Why didnt they make the control surfaces in
metal too?


Some aircraft's interior walls was covered
in what looks like some kind of insulation.
Usually something that looks like a quilted
diamond material. What is the purpose of this
stuff...sound insulation, heat insulation or
to protect crew from sharp projections underneath?

[HundertzehnGustav]

for the insulations, i guess it was for heat...
if a Guy touched the fabric at cold altitudes, his fingers would not freeze. but if there was aloominum, no fabric, his fingers would... (?)

for splinter protection? I guess not. if the aloominum is damaged by AAA or gunfire, fabric protection is not enough, right?

for sound protection... naaah... these were military planes, so, comfort or soundproofing was not a design goal of big importance. Just hand the crew a handful of "oropax" earplugs?

...i guess...?

[soldaten]

Bare skin does stick instantly to cold metal
so your explantion that it could be thermal related insulation
makes sense.

[tater718]

Fabric control surfaces are lightweight and are less subject to flutter.They were are cheap to produce as aluminum was costly.The only disavantage is that fabric surfaces deteriorate rapidly outdoors.Since these planes had an expected service life of less than 2 years,this was not a big problem.

[soldaten]

Ah that makes sense, I remember reading how aircraft designers, especially with the Zero,
bent over backwards to save weight in any way they could.

[RGA]

AFAIK plywood is an exceptionally strong material, cheap, very easy to work with. Its only drawbacks are weight and lifetime. Mosquito was built mostly of plywood and we all know how good it was.

[Pursuivant]

If this is the case, why was fabric retained for the control surfaces?

In addition to weight, cost and flutter resistance. Fabric covering was handy because it was relatively quick and easy to work with, used non-strategic materials (some countries feared shortages of aluminum or steel, or actually had shortages) and could be made and applied using different machines and tools than those needed to make and assemble metal parts.

If properly doped, painted, and cared for, the lifespan of canvas can be considerably longer than just 2 years.
 

Why didnt they make the control surfaces in metal too?

As metal-working skills got better, and as planes got bigger and faster, that's exactly what the manufacturers did. Remember, the WW2 era was a transitional era in aviation history. In 1939, some countries went to war with canvas-skinned biplanes as their first-line fighters. By 1945, the leading air forces were fielding jets.

Some aircraft's interior walls was covered in what looks like some kind of insulation.

I have no clue what this was for. My guess is the purpose depended on the aircraft. Padding to protect crew from sharp edges or bitterly cold metal surfaces seems like good guesses. In other cases, it could have been an attempt at sound insulation especially for planes where there was some attempt made at crew and passenger comfort, like transport planes. Although WW2-era planes were loud, a bit of sound insulation might make the difference between "loud" and "painfully loud."

Other possibilities are that it was a cheap way of protecting exposed parts (e.g., cables, wiring) from the crew and vice-versa. It could also have been asbestos-filled material designed to give the crew some protection from flames, or possibly even an attempt to reduce vibration.

[tater718]

But there is also the little "fly in the ointment" with the Corsair's wings.They remained fabric because it would take a major redesign to change things.The fuel was carried in the fuse and droptanks.
Many homebuilt low to medium-speed AC are still covered with fabric.

[HundertzehnGustav]

wt FFF? corsairs in fabric wings?
have to dig that one up...

lol... canvas plane doing 400 mph and more... amazing.

[Batbomb]

Can I also ask for Something?
Whats the advantage of projected reticles to iron reticles before Gyro Gunsights where Invented
And why have all projections a yellow colour and no green, blue etc???

[SAS~CirX]

You guys already answered about the fabric control surfaces. One must keep in mind that these planes were in a transition phase of aeronautics, so youll find both new and dated technologies and approaches in the same design often.

I can answer the quilted covering question. It is for sound, and for preventing snagging.

It is basically a duvet like quilted sheets that are cut to fit the length of the fuselage, and clip into place, you saw it on the Dakotas. If you have ever been in a Dak with the "carpet walls" removed, you will immediately see why they are there. That plane is fucking scary, wind leaks in everywehre , and it is loud a s hell.

You also see it on modern military transports, like the C130's.

These planes, have not cosmetic inner cabin inside the outer shell, where in electronics, wires and all sorts of stuff can be hidden. And if you are in full combat gear with some other guys in the back of one of these, expecially smaller stuff like a transall or a DC3, then you can see how it would be impossible for you not to catch and rip out wires and stuff it they were not covered.

And then of course it is for sound absorbtion. It is basically the same reason that modern infantry vehicles and armoured personel carriers have carpeting stuck to the inside surfaces, or the insides surfaces of modern cars have a foam covering.

Other than that, it does nothing. It is not a specific fire-retarder, nor will it stop any schrapnel or bullets particularily well. It does stop arrows though.

Now, go and wonder how I came to know THAT....

[SAS~CirX]

Can I also ask for Something?
Whats the advantage of projected reticles to iron reticles before Gyro Gunsights where Invented
And why have all projections a yellow colour and no green, blue etc???

I can also answer this. Projected reticles are always superior, because it makes aiming that much easier. That is why even infantry weapons to-day often use red dot sites (which is also a type of reflector gunsight). Not only does not make it faster to aim, but it also does not obscure the target .

The reason for the colour: The colour of the brightest bulbs at that time was yellow. "White light" is a relatively modern invention. Yellow also displays well against the outside But other colours may work better, depending on the circumstance. Todays huds have multiple colours, but yellow still works great. WW2 reticles were a product of the bulbs though,and were predominantly yellow that tinged towards the red spectrum.

The old reflection sites from WW2 usualy had a dimming setting, that adjusted the brightness of the glow, and german ones had an additional shaded glass for very bright environments.

The rumour that german reticles were blue is utter BS, and I know this because I was "there" when the rumour started. I was involved at that time with research for the museum, and specifically into Revi's. At that stage there were absolutely NO pictures on the web or easily available of a working Revi.

But one day, there was a picture. And it was posted by members of the finnish virtual pilots association (I think that is the name of them), of a visit to a museum where they were allowed to handle a Revi12. And the picture shows a beautifull Blue Reticle. I still have that photo somewhere.

This was the reason that IL2 first came out with blue reticles, and why so many people think there were blue reticles in german planes.

The truth is, that the Revi12 in the museum those guys visited, did not have a working bulb in, nor a suitable powesource. So one of the guys opened the bottom up, and shone into it his little LED flashlight that one gets on keychains. And the result was, a blue LED powered reticle.

The truth came out later as more guys who actualy HAD Revi's and proper powersources got on the net, and more pictures were shared. And the blue reticles dissapeared very quietly from all games.

But it is pretty abvious though, isnt it: If you had to make a reticle for a pilot who is flying around up there in that enormous expanse of blue sky, what is the WORST colour you could make the reticle?