The rudder is one of three primary flight control surfaces found on an airplane. It is a movable surface hinged to the fixed surface that is located at the rear of the aircraft called the vertical stabilizer, or fin. The rudder controls movement of the airplane about its vertical axis and causes the airplane's nose to move to the right or left and point in a different direction. This motion is called "yaw."

Control cables connect the rudder to the rudder pedals. Pushing down the right rudder pedal moves the rudder to the right and causes the plane to turn to the right. Pushing down the left rudder pedal turns the plane to the left.