FAA Ground School Practice Test

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

1. To control pitch

2. To control roll

3. To control yaw

4. To control speed

The correct answer is: To control yaw

The primary function of the rudder on an airplane is to control yaw. Yaw refers to the left or right movement of the aircraft's nose around the vertical axis. The rudder is a vertical control surface located on the tail of the aircraft, and it works by deflecting airflow. When the pilot pushes on the rudder pedals, the rudder moves in the direction of the desired turn, allowing the airplane to rotate its nose and change its heading. This is particularly important during coordinated turns and in maintaining directional control during flight. In the context of aircraft dynamics, each control surface serves a specific purpose. The ailerons are responsible for controlling roll, enabling the aircraft to bank left or right; the elevator, typically located on the horizontal stabilizer, controls pitch, which affects the nose's up or down position; and speed is generally controlled through throttle adjustments rather than a specific control surface. Thus, the rudder's role in managing yaw is vital for safe and effective maneuverability in flight.