Re: barrel roll in 727 ?!!

From:         neilcothran@worldnet.att.net (John N. Cothran)
Organization: AT&T WorldNet Services
Date:         04 Aug 96 16:44:53 
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steven tobey <stobey@flash.net> wrote:

>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.
>>
>> Never heard that story before. Do you have more information about this
>> "incident" ?

>The story is true although I can no longer vouch for the date and flight
>number of the TWA B727. I believe the event took place in the late '70s
>and from what little I remember the crew was manipulating the leading
>edge slats (by pulling the circuit breakers???) in an attempt to cruise
>at a higher altitude. This failed, the aircraft may have stalled, then
>rolled over and lost several thousand feet of altitude before recovering.
>During the recovery the landing gear was deployed to help slow the
>aircraft's descent damaging the gear doors. The aircraft made an
>emergency landing safely. IIRC the Captain's name was "Hoot" Gibson.

Several years ago, I attended a "short course" taught by Prof. Jan
Roskam, of Kansas University.  Dr. Roskam related the above story
anecdotally during one of his lectures regarding aeroelastics.
According to memory (supported by re-reading this thread) the crew was
attempting to partially extend the trailing edge flaps to a position
which was actually somewhere between the UP detent and the first
detent (2 deg? 5deg?).  In order to prevent the deployment of the
leading edge slats and Kreuger flaps, the "theory" was that the main
leading edge drive circuit breakers would have to be pulled.  Whatever
the exact sequence of events was, at some point the leading edge
devices extended.  The outboard LE slat on the port wing was ripped
away, leading to the "barrel roll" (which I believe as actually
several rolls).  Dr. Roskam also related that he was subsequently
retained by Boeing as an "expert witness" during the ensuing legal
melee, and was involved that extensive evaluation of the incident,
including both simulation and "reflights" that were made by Boeing.
Also, I recall him telling us that the wing/body fairing area of the
fuselage had been slightly and permanently "bent" (or was it the wing
root joint?) from the stresses imposed by deployment of the landing
gear during the (successful) effort to regain control.  Anyway, his
report was that all the subsequent checks of the aircraft indicated
that it was perfectly "safe", so it was placed back into service.
Interestingly enough, he reported, that aircraft exhibited a noticable
drop in total fuel consumption over the remainder of it's service life
at TWA.   Ending on a humorous note, he also related that, several
years later, on a vacation flight with his wife, he noted the tail
number of the aircraft they were boarding, and decided not to tell
her............