Re: Aircraft Maneuvers

From:         Don Stokes <Don.Stokes@vuw.ac.nz>
Organization: Victoria University of Wellington
Date:         08 Sep 95 02:35:34 
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tonyB@seavixen.demon.co.uk writes:
>Tex Johson did indeed barrel roll the prototype B707, I have some video
>footage of that event, and whilst I accept that a properly executed barrel
>roll is positive all the way round, there remain plenty of scope for error.
>If Tex had got it wrong, Boeing would probably not be in existance today,
>because they were betting there shirt on the B707.

That's not really true.  When Boeing decided to build the Dash-80, they
were making huge profits from military aircraft, particularly the B-52,
and the Dash-80 was also a prototype for the KC-135 to feed said B-52s.
Also, Boeing was being hit hard by excess profit taxes.  So the risk was
not that great, and the payoff was getting taken seriously as an airliner
manufacturer.

>There was a rumour many years ago that a Lufthansa crew had barrel rolled
>a B707 during training, and having got the roll wrong, managed to lose,
>and I mean lose two engines on one wing.  They literally came off the
>airframe!

Is this a confusion with Dutch roll?  Early 707s had insufficient lateral
stability, a fault fixed at Boeing's expense by adding more tail, and
could easily yaw enough that the asymmetric airflow over the swept wings
would start to roll the plane.  The extra drag on the wing away from the
yaw would yaw it back, but the resulting oscillation would just get
worse until the pilot corrected it or the plane flipped.  This
characteristic of swept-wing aircraft is why the yaw damper is there,
but on the 707 the yaw damper wasn't enough to prevent this happening.
Several cases of this on training flights, where inexperienced pilots
couldn't correct the yaw in time, resulted in lost engines and/or
complete loss of airframe and lives.

I didn't think any Lufthansa planes were affected though.

Dutch roll is *not* a "properly executed roll" ... 8-)

--
Don Stokes, Network Manager, Victoria University of Wellington, New Zealand.
don@vuw.ac.nz(work) don@zl2tnm.gen.nz(home) +64 4 495-5052 Fax+64 4 471-5386