What motion does the rudder primarily control?

The rudder is primarily responsible for controlling yaw, which is the movement of an aircraft's nose from side to side around a vertical axis. This motion is crucial for maintaining coordinated flight and making turns. When the pilot deflects the rudder, it generates a horizontal force that causes the tail of the aircraft to move in one direction, resulting in the nose yawing in the opposite direction.

Understanding yaw is important for pilots because it helps to ensure that the aircraft turns smoothly and efficiently while maintaining balance with the other control surfaces, like the ailerons and elevators, which control roll and pitch, respectively. The rudder is particularly influential during takeoff, landing, and in situations where wind causes an unwanted yaw movement. By effectively using the rudder, pilots maintain control and navigate the aircraft more precisely.