An imminent stall is one in which the airplane is approaching a stall but is not allowed to completely stall. This stall maneuver is primarily for practice in retaining (or regaining) full control of the airplane immediately upon recognizing that it is almost in a full stall or that a full stall is likely to occur if timely preventive action is not taken (Fig. 11-21).
The practice of these stalls is of particular value in developing the pilot's sense of feel for executing maneuvers in which maximum airplane performance is required. These maneuvers, therefore, require flight with the airplane just on the verge of a stall, and recovery initiated before a full stall occurs. As in all maneuvers that involve significant changes in altitude or direction, the pilot must ensure that the area is clear of other air traffic before executing the maneuver.
These stalls may be entered and performed in the attitudes and with the same configuration as any of the basic full stalls or other maneuvers described in this chapter. However, instead of allowing a complete stall, when the first buffeting or decay of control effectiveness is noted, the angle of attack must be reduced immediately by releasing the elevator back pressure and applying whatever additional power is necessary. Since the airplane will not have been completely stalled, the pitch attitude needs to be decreased only to a point where minimum controllable airspeed is attained or until adequate control effectiveness is regained.
The pilot must promptly recognize the indication of an
imminent stall and take timely, positive control action to prevent a full
stall. Performance is unsatisfactory if a full stall occurs, if an excessively
low pitch attitude is attained, or if the pilot fails to take timely action
to avoid excessive airspeed, excessive loss of altitude, or a spin.