Definition
An aerodynamic stall is a sudden loss of lift that occurs when the wing's angle of attack exceeds the critical angle, causing the smooth airflow over the upper surface to separate and become turbulent. A stall is determined by angle of attack alone, not by airspeed, attitude, or power setting — a wing can stall at any speed, in any attitude, and at any power setting if the critical angle of attack is exceeded.
Plain English
A stall happens when the wing is tilted too steeply into the oncoming air. The air can no longer flow smoothly over the top of the wing, so the wing stops producing enough lift to hold the airplane up. It is about the angle of the wing relative to the air — not how fast the airplane is going.
Context Anchor
Seen in stall awareness, slow flight, takeoff, landing, and recovery training.
Derivation
From the older English use of 'stall' meaning to come to a standstill or stop working. In aviation it does not mean the engine has stopped — it refers specifically to the wing no longer producing enough lift because the airflow has separated.
Why Pilots Care
Unrecognized stalls are a leading cause of loss-of-control accidents; every pilot must be able to recognize and recover from them.
Grounding Statement
A stall can occur when the airplane is flying slowly, pulling up sharply, turning too tightly, or any time the wing is asked to meet the air at too steep an angle.
Intuition Check
Stall does not mean the engine quit or the airplane stopped moving. In this context, it means the wing has lost smooth airflow because its angle to the oncoming air is too great.
Example Sentence 1
During training, the student practiced recognizing the early signs of stalls — buffeting, mushy controls, and the stall warning horn — and recovering by reducing the angle of attack.
Example Sentence 2
Before turning base, the pilot reduced power and watched airspeed closely to avoid entering a stall during the approach.