Definition
Devices mounted on the leading edge of a wing that detect when the airflow is approaching the angle of attack at which the wing will stall, and trigger a cockpit warning to the pilot. Common types include a small vane or tab that lifts as the stagnation point on the leading edge moves, and pressure-sensing ports that detect the change in airflow pattern near the stall. Because these sensors sit on the leading edge, they are vulnerable to ice accretion, which can disable or delay the warning.
Plain English
Small parts on the front edge of the wing that sense when the wing is about to lose lift and warn the pilot before it happens.
Context Anchor
Seen during preflight checks, stall-warning system checks, and discussions of anti-ice protection for small external aircraft parts.
Derivation
“Stall” originally means to stop or come to a standstill. In flying, it means the wing is no longer making smooth, reliable lift because the airflow has broken away. “Sensor” comes from the idea of sensing or feeling; a stall-warning sensor is a part that “feels” the airflow so it can warn the pilot.
Why Pilots Care
These sensors give early warning of an approaching stall so the pilot can lower the nose and regain airflow before control is lost.
Intuition Check
A stall here is not an engine quitting. It is the wing losing smooth airflow and lift, and the sensor is there to warn the pilot before that happens.
Example Sentence 1
During the preflight, the pilot gently checked the stall-warning sensor on the left wing to confirm it moved freely and triggered the horn in the cockpit.
Example Sentence 2
Ice forming on the wing caused the stall-warning sensors to activate earlier than expected in the approach.