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| CHAPTER 6. Flight Manuevers
Power-Off Stall Manuever The practice of power-off stalls is usually performed with normal landing approach conditions in simulation of an accidental stall occurring during landing approaches. Aircraft equipped with trim should be trimmed to the approach confi guration. Initially, 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 traffi c. To start the power-off stall maneuver, reduce the throttle to idle (or normal approach power). Increase airspeed to the normal approach speed and maintain that airspeed. When the approach attitude and airspeed have stabilized, the aircraft’s nose should be smoothly raised to an attitude that induces a stall. If the aircraft’s attitude is raised too slowly, the WSC aircraft may slow only to minimum controlled airspeed and not be able to reach an angle of attack that is high enough to stall. The position of the control bar at which the WSC stalls can vary greatly for different manufacturers and makes/ models. Some can stall abruptly when the control bar is inches from the front tube. If the aircraft’s attitude is raised too quickly, the pitch attitude could rise above the manufacturer’s limitation. A good rule of thumb is 3 to 4 seconds from stabilized approach speed to pull the control bar full forward. The wings should be kept level and a constant pitch attitude maintained until the stall occurs. The stall is recognized by clues, such as buffeting, increasing descent rate, and nose down pitching. Recovering from the stall should be accomplished by reducing the angle of attack by pulling the bar back and accelerating only to the trim speed while simultaneously increasing the throttle to minimize altitude loss if needed. Once the WSC accelerated to trim speed, the control bar can be pushed out to return back to normal trim attitude and speed. If there is any rolling during the stall or the stall recovery the control bar should be moved side to side to maintain a straight heading. It is not necessary to go into a steep dive in a WSC aircraft to recover from a stall. This only loses more altitude than required and should be discouraged. The nose should be lowered as necessary to regain fl ying speed and returned to a normal fl ight attitude as soon as possible. [Figure 6-22]
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 fi nal approach. During the practice of these stalls, care should be taken that the turn continues at a uniform rate until the complete stall occurs. When stalling in a turn, it does not affect the recovery procedure. The angle of attack is reduced and the wings leveled simultaneously with power applied if needed for altitude control. In the practice of turning stalls, no attempt should be made to stall the aircraft on a predetermined heading. However, to simulate a turn from base to fi nal 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. |
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