Re: Reuters Story On Peru Boeing 757 Crash and DR

Date:         10 Nov 96 04:52:43 
From:         Pete Finlay <pete@meads.demon.co.uk>
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In article <airliners.1996.2287@ohare.Chicago.COM>, Paul Nixon
<khobar@paloverde.com> writes

>McD-D knew about the difficulty with this door design because of an
>earlier loss of such from an American Airlines DC10. But that doesn't
>change the fact that the ground crewman was the one who was responsible
>for making sure the door was properly closed.

the American Airlines DC-10 crash was nothing to do with the cargo door;
it was the failure of one of the wing engine pylon hinge brackets, which
caused the engine to detatch, which ripped out the hydralic and
pneumatic lines on that side. This, in turn, caused the L/E slats on
that side to be blown back by the forward air pressure, and that flipped
the aircraft onto it's back. BTW, I am assuming you are talking about
the American Airlines DC-10 that went in at Chicago.

The DC-10 cargo door problem was a two part problem. Subsequent tests
proved that it was possible to actually have the door appear closed, but
not locked. When the door blew, the differential pressure between the
cabin above, and the (now depressurized) cargo hold below caused the
cabin floor to bow downwards towards the cargo hold. This action
impinged onto the flying control cables which made the aircraft
uncontrollable.

As a fix, McD.D firstly modified the cargo door so that there were a
system of visable locks that positively held the door shut, and then
they incorporated blow-out panels in the bottom of the cabin sidewall,
so that if there was ever a major difference in pressure between the
cabin and the cargo holds again, the panels would open and allow the
pressure to equalize, which would stop the floor bowing onto the control
cables.

Philosophically speaking (!), both accidents were the results of human
error more than an aircraft fault. The American Airlines one at Chicago
was caused by poor maintenance procedures (they changed the engine using
a fork-lift truck and cracked the bracket in the process), and the
Turkish one was caused by the idiot that was responsible for closing the
door.

fly safe
--
Pete Finlay
pete@meads.demon.co.uk
Boeing 747 Senior Flight Engineer