On Jan 2, 6:09*pm, Bruce Hoult wrote:
On Jan 3, 12:01*am, Derek C wrote:

Actually the only totally reliable sysmptom of being stalled is that
the elevator will no longer raise the nose.

But that is neither necessary nor sufficient!

If you put enough weight in the front cockpit then there are plenty of
gliders where you reach the back stop while they are still flying just
fine.

Conversely, there are also plenty of gliders with sufficiently
powerful elevators that the wing can be stalled and you're mushing at
500+ fpm but you still have perfect control over the attitude of the
nose and can raise or lower it at will. Not to mention other aircraft
such as the F/A-18 which can be flown in perfect control with the wing
stalled at huge angles of attack.

I see in another post the definition:

Admittedly that is still a stall according to FAR23/25 definitions "a stall is produced, as shown by either:
(1) An uncontrollable downward pitching motion of the airplane;
(2) A downward pitching motion of the airplane that results from the activation of a stall avoidance device (for example, stick pusher); or
(3) The control reaching the stop."

Without having that document in front of me I will hazard a guess that
this is not a definition of a stall, but rather a definition of the
standards for what a pilot should do in order to pass a practical
flight examination. They're not going to fail him when the aircraft
fails to actually stall because the elevator reaches its stop first,
so they explicitly allow that as a signal that the pilot is allowed to
terminate the "stall" attempt and commence the stall recovery
procedure.

The only true definition of a stall is when the wing is at an angle of
attack such that a further increase of AoA produces a decrease of
lift.

*Usually* this will be accompanied by a large increase in drag such
that the combination of lift and drag is easily capable of supporting
the aircraft against gravity at a low speed and steep nose up descent
angle, but that may not necessarily always be the case and some
aircraft might speed up while stalled (perhaps at high altitude?).

The context of those stall definitions have to to with aircraft
certification. I think our towing discussion should stick with the
"aerodynamic" (AoA) definition.

As far a stalls on the practical test......the practical test
standards leaves a lot up to the examiner. I train my students for
what I call "baby stalls"....where you just creep up on it, and the
glider barely stalls, and the recovery is almost immediate. I also
train them for "monster stalls" where you really pull back hard, and
fast, resulting in a major nose up, followed by major nose down
attitude and a more "active" recovery needed.

The former is perhaps more realistic....in that in the real world
flying, the pilot might be more likely to stall this way. It also is
a good way to teach stall recognition and stall avoidence.

The later however shows more "plane handling", and more of the flight
envelope, almost more like an aerobatic maneuver.. Also shows no
"fear" of stalling. But unlikely to happen this way in the real
world.

I have sent students to examiners who like the stalls demonstrated in
the "baby" way, and others who like the "monster" way. I tell my
students to ask the examiner what he/she wants and perform the stall
and recovery accordingly.

During flight reviews, I find many pilots who, when I ask them to
demonstrate a stall and recovery, simply lift the nose up a bit, the
glider slows, and they push the nose back down.....never an actual
stall. To me this shows either fear, lack of understanding, or lack
of the "feel" of the glider. Thjen I demonstrate a "real stall" and
have then practice a bit.

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