Re: 747 wing stress test: This can't be true can it?

Date:         09 Apr 97 03:09:27 
From:         hackett@southwind.net (Kim Hackett)
Organization: Your Organization
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>I just received a question regarding stress tests on 747s.
>
>"Is it true that a 747's wings were pulled upwards until both
>wing tips touched. (In some sort of stress test)."

>I know that they do all sorts of stress tests but this can hardly be true,
>can it? My reference archives don't mention this at all. Sure, the wings
>can withstand some stress but this is a bit too heavy, I think.

No, the wings are not static tested until the tips touched.  I do not
know the deflection on the 747 static tests.  The B-52 wing tip deflections
were on the order of 30 some feet of total deflection if I remember
correctly.

We recently static tested the wing of the Citation Excel at Cessna and
the deflection at maximum ultimate load was 32 inches.