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

The primary function of the rudder in an aircraft is to control yaw and maintain coordinated flight. The rudder is a vertical control surface located on the tail of the aircraft, and it works by changing the airflow around the tail when it is deflected left or right. This deflection causes the aircraft to rotate about its vertical axis, allowing the pilot to steer the aircraft in the desired direction.

Yaw is the movement of the aircraft's nose left or right, and maintaining coordinated flight ensures that the aircraft is moving in a straight line without skidding or slipping, which can occur if the ailerons are used without corresponding rudder input. Proper use of the rudder is essential during various flight maneuvers, including turns, to prevent adverse yaw and maintain smooth and controlled flight.

The other options describe functions that do not pertain to the rudder. Pitch and altitude control is managed by the elevators, thrust management is related to the throttle, and stability during turbulence typically involves a combination of the ailerons, elevators, and overall aircraft design rather than specifically the rudder.