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>Regardless of AOA the wing will stall when the speed drops to the level
>appropriate for the loading.
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>
Hi, all
There must be some confusion between stall and sink.
Patrick, I believe you mean "the wing *sinks* when the speed drops...."
A stall happens when, due to high AOA, the airflow separates from the
upper surface to a significant extent. Stall is entirely AOA related,
and when flying aerobatics, we can stall at any speed. That's what flick
(or snap) manoeuvres are. Of course if you exceed a safe flick entry
speed, you may overstress the aeroplane.
Kinglsey is right in his demonstration. Contrary to the popular saying,
there is no such thing as a "full stall landing". I mean, if you stall
near the ground, the consequence cannot possibly be called a "landing",
but rather "some plastic/metal/wood heap on the runway" ;-)
Consider that during a stall, the nose of the aircraft drops rather
sharply. An if the airplane is not too well behaved, so does a wing.
What happens during ground effect deceleration is a *gradual* reduction
in lift, compensated by a gradual increase in AOA, until, when the
aeroplane has run out of speed, and the pilot out of pitch, lift cannot
be maintained any longer and the aeroplane gently sinks on to the ground.
For what it's worth,
Regards,
Gilles Thesee, aerobatics FI
Grenoble, France
http://contrails.free.fr
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