Mailing List lml@lancaironline.net Message #13956
From: J H Webb <airmale@bright.net>
Sender: Marvin Kaye <marv@lancaironline.net>
Subject: Stalls
Date: Sun, 16 Jun 2002 22:24:57 -0400
To: <lml>
> Start high, keep the ball in the center and don't pick up a falling
wing with aileron.

This is in the arena of OWT (old wife's tails).  As an aeronautical
engineer and years
as an experimental test Pilot I can tell you that we (the designers,
test pilots, and
Aerodynamicists) have made great strides in eliminating the problem of
Serious
adverse yaw at the stall by primarily the use of differential ailerons
and improved
wing design.

    In hundreds of airplanes flown and many experimental designs tested
you well get
much better response and safer stalls using coordinated control usage.
Maybe the
last airplane that was quantity produced that was nasty in that respect
was the
F-100. The Lancair series is very good and has good response to
coordinated
control usage.  It has both differential ailerons and a good wing
design. We did
comparison evaluations of competitors airplanes when I was working for
the manufacturer and we saw no certificated aircraft that required
special control inputs (i.e. no aileron or like in one military case an
airplane that used no rudder for spin recovery).

   The best technique for stalls and spin recovery is coordinated
controls.  My most unique GA experience was to do 219 experimental spins
in a light (under 12,500) twin. The vast majority of twins are never
spun.  It is interesting to note that you could reduce the recovery
rotation and altitude lose, by using all three primary controls in
concert. You could reduce the rotation but 1/3 to 1/2 turn by using
ailerons in the recovery.  BTW the altitude loss with an experienced
pilot in the twin was only 1800 feet average for a one turn spin then
recovery.  The big problems in recovery are airspeed and G loading.  The
recovery after a 1 turn spin is to not exceed the red line and to keep
the G loading below 3.8 and it was difficult to keep the numbers within
the limits.  When you point a streamlined airplane straight down and
then push the stick ahead even briefly, you get a tremendous speed
increase very quickly.

As an interesting side note if you promptly applied anti spin control at
the first hint of a spin the recovery could be made with almost no
altitude loss. This would apply well to any well designed light
airplane.  The trick is recognizing the incipient spin.  There are
virtually no airplanes that will spin without poor coordination……. More
than ˝ ball out of center.

   As was mentioned by one list subscriber there is a lot of benefit
gained by practice as trying to recover for the first time from a poorly
coordinated stall at low altitude in the traffic pattern will most
likely have a very bad outcome. If you have practiced and are familiar
with the appearance of an incipient stall, the recovery, even if you
ignore the early indications, can be with very little altitude loss
(less than 200’). But you must recognize the early indications and this
is very difficult to do without practice.



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