Re: barrel roll in 727 ?!!

From:         David Lednicer <dave@amiwest.com>
Organization: Analytical Methods, Inc.
Date:         29 Jul 96 02:29:37 
References:   1 2 3
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Daan Vlaskamp wrote:
>
> >The crew of a (TWA?) 727 was sort of "playing" with the flaps at cruise
> >to milk out a little bit better fuel economy.  They did a barrel roll
> >before recovering, losing 10's of thousands of feet of altitude in the
> >process.  Not a boring flight at that point.

	The pilots were apparently "bootlegging".  This involved throwing
the circuit breakers for the slats and then running the flaps out to the
first extension limit (Flaps 5?), while in cruise.  This has the effect
of lowering the aircraft's nose, which is reputed to lower the drag on a
727.  Story I heard is that somehow the slat circuit breakers got reset,
and the slats came out.  The crew tried to retract them, but one stuck,
causing the roll and later ripping off.  The aircraft landed at Detroit
Metro and after a thorough inspection, was returned to service.

	When Valsan was developing winglets for the 727, problems cropped
up regarding the additional root bending moment produced by the change in
wing spanwise loading.  They got around this by rerigging the flaps, much
like the "bootleg" setup.  This shifted the lift distribution back
inboards, curing the bending moment problem.  Story I heard is that the
rerig was also reduced the aircraft's drag a little bit too.

-------------------------------------------------------------------
David Lednicer             | "Applied Computational Fluid Dynamics"
Analytical Methods, Inc.   |   email:   dave@amiwest.com
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