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

The primary function of the rudder on an aircraft is to control yaw, which refers to the aircraft's movement around its vertical axis. When the pilot moves the rudder to the left or right, it deflects the airflow around the tail of the aircraft, causing the nose to turn in the direction of the rudder input. This is crucial for maintaining coordinated flight, especially when making turns, as it helps to counteract adverse yaw—the tendency for the nose of the aircraft to swing opposite to the direction of a turn.

In contrast, controlling pitch generally involves the elevators located on the horizontal stabilizer, which regulate the angle of the aircraft's nose up or down. Roll is controlled by the ailerons, which are found on the wings and manage the aircraft’s tilt from side to side. Stabilizing the fuselage can involve multiple components and is not a primary function of any single control surface like the rudder. Understanding the specific roles of the various flight control surfaces is essential for safe and effective maneuvering of an aircraft.