FAA Flight Controls Practice Test

Differential lift in an aircraft is primarily controlled by the ailerons. Ailerons are hinged surfaces located on the outer part of each wing. When a pilot wants to roll the aircraft, one aileron is deflected upward while the other is deflected downward. The downward-deflected aileron increases the lift on that wing, while the upward-deflected aileron decreases the lift on the opposite wing. This difference in lift causes the aircraft to rotate about its longitudinal axis and roll in the direction of the wing with the increased lift.

In contrast, the elevator is responsible for controlling pitch, allowing the aircraft to climb or descend. Flaps are used to increase lift during takeoff and landing but do not specifically control differential lift for rolling an aircraft. The rudder primarily controls yaw and helps maintain coordinated flight but does not influence lift differently between the wings. This distinguishes the role of ailerons as essential in managing differential lift during maneuvers.