Definition
A cockpit warning system that alerts the pilot when the wing's angle of attack is approaching the critical (stalling) angle, regardless of airspeed, attitude, or weight. Activation occurs before the actual stall, giving the pilot time to recover. Devices may be aerodynamic (a reed-type horn powered by airflow through a slot in the leading edge), electrical (a vane or tab that closes a switch and sounds a horn or lights an indicator), or more advanced systems such as stick shakers and stall warning computers found in larger aircraft.
Plain English
An onboard alert that warns the pilot the wing is getting close to stalling, so action can be taken before the stall actually happens.
Context Anchor
You encounter this during stall training, slow flight, takeoff and climb, landing approach, and some preflight checks.
Derivation
“Stall” originally means to stop or come to a halt. In aviation, it does not mean the engine stops; it means the wing is no longer making normal lift because the airflow over it has broken down. A “warning device” gives notice before that condition fully occurs.
Why Pilots Care
Gives the pilot time to lower the nose and recover before a full stall occurs and control is lost.
Intuition Check
Do not read “stall” here as an engine problem. A stall warning device warns about the wing getting close to losing lift, not the engine quitting.
Example Sentence 1
During the preflight check, the pilot lifted the small vane on the wing's leading edge to confirm the stall warning horn sounded in the cockpit.
Example Sentence 2
The student pilot responded immediately to the stall warning device by reducing back pressure on the controls.