Which control is primarily responsible for regulating the direction an aircraft turns?

The rudder is the control primarily responsible for regulating the direction an aircraft turns. It is a vertical control surface located on the tail of the aircraft, and when the pilot applies pressure on the rudder pedals, it causes the rudder to move left or right. This movement creates aerodynamic forces that pivot the aircraft around its vertical axis, enabling it to turn in the desired direction.

While other controls such as the elevator, throttle, and flaps do have roles in aircraft handling, they do not primarily dictate the turning motion. The elevator controls the pitch, which affects the aircraft's ascent or descent, while the throttle manages engine power, influencing speed rather than direction. Flaps are used to increase lift during takeoff and landing but do not directly impact the aircraft's turn capabilities. Thus, the rudder’s specific design and function make it the main control for altering the aircraft's heading.