Wednesday, February 11, 2009

Full Stalls Power-Off

The practice of power-off stalls is usually performed
with normal landing approach conditions in simulation

of an accidental stall occurring during landing
approaches. Airplanes equipped with flaps and/or
retractable landing gear should be in the landing
configuration. Airspeed in excess of the normal
approach speed should not be carried into a stall entry
since it could result in an abnormally nose-high
attitude. Before executing these practice stalls, the
pilot must be sure the area is clear of other air traffic.

After extending the landing gear, applying carburetor
heat (if applicable), and retarding the throttle to idle
(or normal approach power), the airplane should be
held at a constant altitude in level flight until the
airspeed decelerates to that of a normal approach. The
airplane should then be smoothly nosed down into the
normal approach attitude to maintain that airspeed.
Wing flaps should be extended and pitch attitude
adjusted to maintain the airspeed.

When the approach attitude and airspeed have
stabilized, the airplane's nose should be smoothly
raised to an attitude that will induce a stall. Directional
control should be maintained with the rudder, the
wings held level by use of the ailerons, and a constant-
pitch attitude maintained with the elevator until the
stall occurs. The stall will be recognized by clues, such
as full up-elevator, high descent rate, uncontrollable
nosedown pitching, and possible buffeting.

Recovering from the stall should be accomplished by
reducing the angle of attack, releasing back-elevator
pressure, and advancing the throttle to maximum
allowable power. Right rudder pressure is necessary to
overcome the engine torque effects as power is
advanced and the nose is being lowered. Power-off stall and recovery.

The nose should be lowered as necessary to regain
flying speed and returned to straight-and-level flight

attitude. After establishing a positive rate of climb, the
flaps and landing gear are retracted, as necessary, and
when in level flight, the throttle should be returned to
cruise power setting. After recovery is complete, a climb
or go-around procedure should be initiated, as the situation dictates, to assure a minimum loss of altitude.

Recovery from power-off stalls should also be
practiced from shallow banked turns to simulate an
inadvertent stall during a turn from base leg to final
approach. During the practice of these stalls, care
should be taken that the turn continues at a uniform
rate until the complete stall occurs. If the power-off
turn is not properly coordinated while approaching the
stall, wallowing may result when the stall occurs. If the
airplane is in a slip, the outer wing may stall first and
whip downward abruptly. This does not affect the
recovery procedure in any way; the angle of attack
must be reduced, the heading maintained, and the
wings leveled by coordinated use of the controls. In
the practice of turning stalls, no attempt should be
made to stall the airplane on a predetermined heading.
However, to simulate a turn from base to final
approach, the stall normally should be made to occur
within a heading change of approximately 90°.

After the stall occurs, the recovery should be made
straight ahead with minimum loss of altitude, and
accomplished in accordance with the recovery
procedure discussed earlier.

Recoveries from power-off stalls should be
accomplished both with, and without, the addition of
power, and may be initiated either just after the stall
occurs, or after the nose has pitched down through the
level flight attitude.

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