Learning Objective 021.05.01.05.04: Explain the methods of locking the controls on the ground and describe ‘gust or control lock’ warnings.

A gust lock or control lock, is an internal or external lock and may be fitted to the control surface or the cockpit control. They stop the flight control surfaces from being moved at all, and are meant for when an aircraft is parked outside with strong or gusty winds. The wind could move the control surfaces all the way to their stops which could cause damage. If these are fitted to the cockpit controls they might be made in a way that it is impossible to move the throttle until the control locks are removed, to avoid the chance of taking off with control locks engaged. It is very important to remove any control locks (internal or external) before flight.