What is the main function of the rudder on an aircraft?

The main function of the rudder on an aircraft is to control the yaw motion, which is the side-to-side movement around the aircraft's vertical axis. The rudder is typically located at the rear of the aircraft and is operated through the use of pedals in the cockpit. When the pilot applies pressure to the left or right rudder pedal, the rudder moves in the corresponding direction, causing the aircraft to turn left or right. This is crucial during various phases of flight, especially during coordinated turns and in crosswind situations, where maintaining directional control is essential.

By regulating yaw, the rudder contributes to the overall aerodynamic stability and control of the aircraft, allowing for smooth maneuvering. The other options relate to different axes of control: pitch is controlled by the elevator, roll is controlled by the ailerons, and while the rudder may assist in landing by helping to manage directional stability during approach, its primary function remains the regulation of yaw.