Stall

Stall occurs when the wing exceeds its critical angle of attack (typically 15-20 degrees), causing the smooth airflow over the upper wing surface to separate. This results in a dramatic loss of lift and increase in drag, regardless of the aircraft speed or attitude.

Warning signs: buffeting, reduced control effectiveness, stall warning horn/stick shaker. Recovery: reduce angle of attack (push forward), add full power, level wings. Modern transport aircraft have stick pusher systems and flight envelope protection to prevent full stalls.

A stall can occur at any airspeed and any attitude — it depends solely on exceeding the critical angle of attack.