My neighbor had a fire in his hangar. The way I understand it is that there was a fire on the ceiling (that's all I know).
The ceiling is above his metal spar Piper J-3 cub. At the moment, I'm assuming the spar is 6061-T6. Are Cub spars ever any other Aluminum alloy?
In any case, 6061-T6 properties will change when sufficiently heated.... decreased yield strength / increased ductility. (not good for spars).
I don't know how hot the fire was or how hot the wing spar got, but the fabric on this airplane was not damaged at all.
What temperature does covering melt? I don't know the brand, but guessing it is a modern Dacron and not cotton or razorback.
What temperature does covering lose it's strength?
I'll assume the spars didn't get as hot as the covering. Fair assumption?
What advice should I offer him regarding the disposition of the material properties of his aircraft? I'm not asking if I should tell him if it's safe to fly...
What I am asking is, what would be the right steps for him to take to determine whether it is safe to fly?
Thanks!
Glenn
The ceiling is above his metal spar Piper J-3 cub. At the moment, I'm assuming the spar is 6061-T6. Are Cub spars ever any other Aluminum alloy?
In any case, 6061-T6 properties will change when sufficiently heated.... decreased yield strength / increased ductility. (not good for spars).
I don't know how hot the fire was or how hot the wing spar got, but the fabric on this airplane was not damaged at all.
What temperature does covering melt? I don't know the brand, but guessing it is a modern Dacron and not cotton or razorback.
What temperature does covering lose it's strength?
I'll assume the spars didn't get as hot as the covering. Fair assumption?
What advice should I offer him regarding the disposition of the material properties of his aircraft? I'm not asking if I should tell him if it's safe to fly...
What I am asking is, what would be the right steps for him to take to determine whether it is safe to fly?
Thanks!
Glenn
