Re: O'Hare Accident

Date:         08 Aug 97 05:41:16 
From:         don@toyunix.zl2tnm.gen.nz (Don Stokes)
Organization: The Wolery
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In article <airliners.1997.1714@ohare.Chicago.COM>,  <m@bang.org> wrote:
>"jdobyns" <jdobyns@mho.net> wrote:
>> My understanding is that modern jetliners have the ability to take off
>> safely even if one engine fails on takeoff.  If so, did they ever figure
>> out why the one flight leaving Chicago in the late 70's crashed after an
>> engine fell off?
>
>There is a significant difference between an engine failing to produce thrust
>and an engine separating from a wing. Certification requires demonstration
>only of the former.

IIRC, the O'Hare crash factors included:

	Power was lost from the missing engine;
	The slats retracted due to damage; and
	Instrumentation that would have indicated that the slats had
	retracted was also damaged in the separation.

thus the pilots, whos' instrumentation was indicating nothing more than an
engine failure, continued with a fairly low-speed (ie maintaining rate of
climb at the expense of airspeed) engine-out procedure, when in fact the
lack of slats on that wing meant that the aircraft wasn't controllable at
that speed.  Remember that you can't see the wing or engines from the flight
deck.

I believe the engine-out procedure was changed following this accident to
use a higher speed (but lower rate of climb) to allow for possible slat
damage.

-- don