Rudder

The moving part of the vertical tail surface of an aeroplane which provides yaw control or the device in the water on a boat that provides directional control.

A boat rudder.

Aircraft rudder. Forces the tail left or right, correspondingly yawing the aircraft right or left. Rudder movement coordinates with the banking of wings to balance a turn.

See also: Aileron, Aircraft, Boat, Elevator, Flight Controls, Steering.