Gust lock

A gust lock on an aircraft is a mechanism that locks control surfaces and keeps open aircraft doors in place while the aircraft is parked on the ground and non-operational. Gust locks prevent wind from causing unexpected movements of the control surfaces and their linked controls inside the aircraft, as well as aircraft doors on some aircraft; otherwise, wind gusts could cause possible damage to the control surfaces and systems, or to nearby people, cargo, or machinery. Some gust locks are external devices attached directly to the aircraft's control surfaces, while others are attached to the relevant flight controls inside the cockpit.