Stalls and Spins: Critical Angle of Attack Explained

Angle of attack, not airspeed

The published stall speeds (V_S0, V_S1) apply only at a specific weight, configuration and 1 G. Pull hard in a steep turn and the wing can stall at a much higher airspeed.

Stall speed and load factor

Stall speed increases with the square root of the load factor. At 2 G (60° bank), stall speed is about 1.41 × the 1-G stall speed. A 50-knot stall becomes about 71 knots.

Pitch attitude ≠ angle of attack

Pitch is the nose relative to the horizon; angle of attack is the wing relative to the oncoming air. In a steep descent the nose can be low while the angle of attack is high. See the AoA in the flight controls lesson.

Stall warning signs

• Stall horn or light
• Buffeting and mushy controls
• High nose attitude with decreasing airspeed (not always)

Recovery (generic; follow your POH)

1. Reduce angle of attack: forward elevator pressure until the stall warning stops.
2. Level the wings with coordinated controls.
3. Add power as needed.
4. Return to the desired flight path; retract flaps in stages.

Spins

A spin requires a stall plus yaw. The classic accident is a skidding turn from base to final: too much inside rudder and back pressure at low altitude. A common generic recovery is PARE (Power idle, Ailerons neutral, Rudder opposite, Elevator forward), but always use your POH. Many training airplanes aren't approved for intentional spins.