Definition
Cockpit devices that alert the pilot when the wing is approaching the angle of attack at which it will stall. Systems range from a simple aerodynamic reed or vane that triggers a horn or light, to electronic units driven by an angle-of-attack sensor that activate aural warnings, warning lights, or a stick shaker before the stall actually occurs.
Plain English
Equipment in the aircraft that warns the pilot before the wing stops producing enough lift to keep flying. The warning typically comes a few knots before the actual stall so the pilot has time to react.
Context Anchor
You encounter stall warning systems during preflight checks, slow-flight and stall training, and in flight any time the airplane gets close to a stall condition.
Derivation
Stall originally meant to come to a stop. In aviation, a stall does not mean the engine stopped; it means the wing’s smooth airflow has broken down enough that lift drops. A warning system is the equipment that alerts you before that happens.
Why Pilots Care
Provides early warning of an impending stall, allowing recovery before the aircraft loses lift and enters a dangerous nose-high attitude.
Grounding Statement
Picture the airplane slowing while the nose is held high: before the wing fully stalls, the system warns you so you can reduce the stall risk immediately.
Intuition Check
Do not read “stall” here as an engine stopping. In this context, a stall is a wing airflow problem, and the warning system alerts you before the wing reaches that condition.
Example Sentence 1
On final approach the stall warning horn chirped briefly, so the pilot lowered the nose slightly and added power.
Example Sentence 2
During instrument approach practice, the stall warning system activated just before the student lowered the nose to recover.