Re: Wing vs. tail-mounted engines?

Date:         04 Apr 2001 16:41:34 
From:         matt weber <mattheww@Qwest.net>
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At 04:43 PM 3/31/01 +0000, Don Stokes wrote:
>Daniele Procida <{$usenet$}@apple-juice.co.uk> wrote:
> >As someone who is scared out of his wits by aeroplanes, I much prefer
> >MD-80s and the like, because the sight of those enormous heavy engines
> >making those delicate wings bend up and down in that terrifying fashion
> >is something I can really do without. At least on a MD-80 I don't spend
> >the entire flight checking to see if the wings are going fall off.
>
>Actually, the wing stresses are lower with the engines on the wing
>because the wing root is not carrying the weight of the engines as well
>as the fuselage.  Remember that the wings carry the plane, not the other
>way around.
>
>Of course, the tail mounted aircraft have correspondingly stronger wing
>root and tail structures to deal with the higher stresses, so the chances
>of the wings falling off are about the same: vanishingly small.
>
>(I can't think of any case of failure of the wing box or root structure
>causing an accident on a post-war commercial airliner -- can anyone?)
That what caused the Two Electra accidents indirectly. The whirl mode
failure of the engine mounts caused the wingbox loading to exeed the design
limits, and the actual failure was the  wings came off the aircraft.  The
fix was to stiffen the wing, and make the engine mounts stronger.

Matt Weber