An air vehicle, such as a munition like a guided bomb or missile, has a control system that allows control surfaces to be mechanically uncoupled from one or more actuators to allow the control surfaces to freely move (rotate) relative to a fuselage of the vehicle, for example allowing the control surfaces to “weather vane” by assuming an orientation corresponding to the direction of airflow past the air vehicle (direction of airflow relative to the air vehicle). When active positioning of the control surfaces is desired, the control surfaces may be mechanically coupled to one or more actuators that are used to position the control surfaces. The selective coupling of the actuator(s) and the control surfaces may be accomplished by selectively coupling together a sleeve that is mechanically coupled to the control surfaces, and a nut that moves along a shaft of an actuator, for example using a resilient device.