A control mechanism includes an existing aerodynamic device, such as a slat 5, that moves between at least one deployed position and a retracted position; and a load-alleviation mechanism 10 arranged to move the aerodynamic device into a load-alleviation position in response to a load 18, such as a gust of wind acting over a predetermined threshold. During flight, an aircraft can experience gusts of wind that cause strain on the wings 4. The addition of a load-alleviation mechanism to a pre-existing aircraft component allows for gust loading to be alleviated without adding significantly to the weight or complexity of the aircraft. The control mechanism may be retro-fitted to existing aircraft.