by Jonathan M. Stern
Stall Recognition And Recovery
Aerodynamic stalls can occur at any airspeed, in any attitude, and at any power setting. Student pilots are quick to forget this warning as they commit to memory a set of specific stall speeds. These memorized stall speeds, however, apply only to straight and level flight. One cannot memorize all stall speeds for all possible configurations, attitudes, and power settings. Accordingly, a pilot must learn to recognize an impending stall from the behavior of the airplane.
Pilots practice stalls (preferably at a safe altitude) so that they can recognize an imminent stall and take appropriate corrective action. When stalls occur inadvertently, they usually do so at low altitudes where there is little room for mistakes. Prompt corrective action must be taken to avoid uncontrolled flight into the ground.
The following list includes common indications of an imminent stall:
- An unusually nose-high attitude may be one indication of an imminent stall, although the airplane can be stalled in a level or nose-low attitude as well.
- The sound of the slowing airflow about the airplane, the sound of the slowing engine (if flying an airplane with a fixed pitch propeller), and the sound of vibration may all give clues to the onset of a stall.
- A sensation of change of speed or direction.
- A decrease in the responsiveness of the airplane to movement of the controls.
- The sound of a stall warning horn (found in the Cessna 182RG).
When you recognize the stall, you need to take immediate steps to prevent or recover from the stall with a minimal loss of altitude:
- Decrease the angle of attack immediately. Promptly move the control yoke forward a sufficient distance to allow the airplane to resume a flyable angle of attack.
- Apply full power smoothly but promptly to help the airplane regain speed and, in turn, regain airflow over the wings.
- Return the airplane to straight and level flight through appropriate coordinated use of the controls.
- Upon completion of the recovery, reduce power to an appropriate setting.