Definition
A mechanical device that holds an aircraft's flight control surfaces (ailerons, elevator, rudder) in a fixed, neutral position while the aircraft is parked, preventing wind gusts from slamming the controls against their stops and causing damage to the surfaces, hinges, or control linkages.
Plain English
A lock that keeps the moving parts on the wings and tail from flapping around in the wind when the aircraft is parked on the ground.
Context Anchor
You encounter gust locks during parking, tie-down, and preflight inspection, especially when checking that the controls move freely before flight.
Derivation
From 'gust' (a sudden strong rush of wind) and 'lock' (a device that holds something in place). The name describes exactly what it does: locks the controls against gusts.
Why Pilots Care
Prevents costly structural damage to control surfaces from high winds and ensures the controls remain undamaged for safe flight after the aircraft has been exposed to weather.
Intuition Check
A gust lock is not something used to handle gusty air in flight. It is a ground-use item that keeps the controls from moving while the aircraft is parked.
Example Sentence 1
After tying the aircraft down for the night, the pilot installed the gust lock to protect the control surfaces from the forecast winds.
Example Sentence 2
During the preflight walk-around, the first step was to remove the gust lock so the controls could be checked for free movement.