PDA

View Full Version : Real aircrafts skin



owlwatcher
10-04-2004, 12:05 PM
Over the weekend had a good walk around of different planes from WWII to now.
You could touch things, rare these days.
B-17,B-24,B-25,assorted jets, A-10 and Late model C-130.
There was small wing assemblys of a B-26 also displayed.

I was surpized at how thin the skins were.Some I could have dented with squeez of two fingers (B-26) skin.
Solid aluminum blades on B-17 and B-24.

C-130 skin was the most solid .Composit material.

A mad spouse with a hammer could do alot of damage. http://forums.ubi.com/groupee_common/emoticons/icon_biggrin.gif

Texas LongHorn
10-05-2004, 05:51 AM
Hey owlwatcher, I been a licensed A & P (Airframe & Powerplant) mech since before they put in the chopper stuff <ggg.> Welcome to the world of real aircraft. All the best, LongHorn

owlwatcher
10-05-2004, 11:23 AM
Done alot of different trades. Never did fine metal work. Was checking the construction and thinking about the damage pictures of planes.
A razor knife would have cut threw the skins.

Quite amazing the planes stayed together.

Fliger747
10-05-2004, 01:14 PM
Hail storms can cause significant damage, even to modern transport aircraft, which have significantly thicker skins! Lightness and strength are the ultimate considerations in aircraft design. Remember that many WWII aircraft were not so far removed from their fabric covered cousins. Indeed most still had fabric covered control surfaces and some such as the Huricane (or string bag too) had significant fuselage covering of fabric as well.

I have always been impressed by the beautifull metalwork on American planes of the era, a country that could afford such luxuries, isolated by two oceans from attack.

CowboyTodd41
10-05-2004, 03:20 PM
The horizontal stabs on my family's Luscombe has a bunch of hail dings in it cause the guy ho owned it before us left it outside in too many storms http://forums.ubi.com/groupee_common/emoticons/icon_frown.gif Bad for a plane thats all aluminum.

TPN_Cephas
10-05-2004, 03:43 PM
The really hard part of being an aerospace engineer is not making an aircraft that is strong enough to take the required stress loadings, but to make it JUST strong enough to take the loads. Anything beyond the specified strength limit is extra weight which has a dramatic effect on performance.

On a 747 the fuselage skin over the wing root is over an inch thick, but by the nose or tail it can get as thin as .06 inches. (which is still way thicker than anything you would find on a WW2 fighter)

Fliger747
10-05-2004, 04:00 PM
Ed Hinneman who was involved at the core of the design of such notable aircraft as the SBD and the A4 Skyhawk once described his philosophy as 'simplicate and add lightness'. He went on to describe the spiral of adding just one pound of weight, which required then additional structure, bigger engine, more fuel, which then required more of the same!

Modern propulsion sysytems is what makes the 747 a practical airplane. The 400 is a big advance over the 200, which was a big advance over the 100. The 400 is enough more efficent to haul 20 tons MORE cargo over a trans Pacific flight than a 200, and use 20 tons LESS fuel! Lighter, stronge structure, better aerodynmics and better engines and controls.

I WWII the US was fortunate to have generally superior (and very reliable) powerplants, even if we did have to steal the Merlin from the Brits. No Griffon P51?

Jungmann
10-05-2004, 06:37 PM
One thing to keep in mind: though a lot of planes on both sides had just first-rate, state-of-the-art engineering (I think of the P-38 and the Fw-190 off the top of my head), none of them were built to last very long. The expected life of a combat airplane was what--200 hours? So sure, you could use a thin grade aluminum skin to save weight, so long as it would hold together for that length of time. And forget about things like corrosion protection--you just didn't need it. The airplane would be war weary, canibalized or lost before that was ever a problem.

One of the challenges of modern warbird restorers must be to built longevity and safety and reliability into structures and systems that were never really designed to have it for very long.

Fliger747
10-06-2004, 05:26 PM
I understand the deterioation of the metal (crystallization) is a real problem trying to restore the zero into flying condition. Apparently the alloy used was quite strong, but not designed with consuderation of withstanding the ravages of time.

I collect and shoot old miltary weapons, and changes even in steel metalurgy over time can be a consideration.