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Flying Handbook Menu > Slow Flight, Stalls, and Spins > Stalls > Recognition Of Stalls
Pilots must recognize the flight conditions
that are conducive to stalls and know how to apply the necessary
corrective action. They should learn to recognize an approaching
stall by sight, sound, and feel. The following cues may be useful
in recognizing the approaching stall.
• Vision is useful in detecting a stall
condition by noting the attitude of the airplane. This sense
can only be relied on when the stall is the result of an unusual
attitude of the airplane. Since the airplane can also be stalled
from a normal attitude, vision in this instance would be of
little help in detecting the approaching stall.
• Hearing is also helpful in sensing
a stall condition. In the case of fixed-pitch propeller airplanes
in a power-on condition, a change in sound due to loss of revolutions
per minute (r.p.m.) is particularly noticeable. The lessening
of the noise made by the air flowing along the airplane structure
as airspeed decreases is also quite noticeable, and when the
stall is almost complete, vibration and incident noises often
increase greatly.
• Kinesthesia, or the sensing of changes
in direction or speed of motion, is probably the most important
and the best indicator to the trained and experienced pilot.
If this sensitivity is properly developed, it will warn of a
decrease in speed or the beginning of a settling or mushing
of the airplane.
• Feel is an important sense in recognizing
the onset of a stall. The feeling of control pressures is very
important. As speed is reduced, the resistance to pressures
on the controls becomes progressively less. Pressures exerted
on the controls tend to become movements of the control surfaces.
The lag between these movements and the response of the airplane
becomes greater, until in a complete stall all controls can
be moved with almost no resistance, and with little immediate
effect on the airplane. Just before the stall occurs, buffeting,
uncontrollable pitching, or vibrations may begin.
Several types of stall warning indicators have
been developed to warn pilots of an approaching stall. The use
of such indicators is valuable and desirable, but the reason
for practicing stalls is to learn to recognize stalls without
the benefit of warning devices.
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