What is the function of ailerons?

Ailerons are critical control surfaces located on the outer wings of an aircraft, and their primary function is to control the roll of the aircraft around its longitudinal axis. This is achieved by altering the amount of lift generated by each wing. When the pilot moves the control stick or yoke to the left or right, one aileron deflects upward while the other deflects downward.

The upward-deflected aileron decreases the lift of that wing, causing it to drop, while the downward-deflected aileron increases the lift of the opposite wing, causing it to rise. This differential lift causes the aircraft to roll towards the side of the wing with the downward-deflecting aileron, allowing the pilot to initiate a turn or maintain a desired bank angle. Understanding this function is essential for effective aircraft maneuvering and in maintaining controlled flight.