What is the use of ailerons on an airplane? Why? It's best to have diagrams.

Function: Aileron refers to a small movable wing surface installed on the outside of the trailing edge of the wing tip. It is the main operating control surface of the aircraft. The roll torque generated by the pilot's differential deflection of the left and right ailerons can make the aircraft perform roll maneuvers.

Why: When operating the ailerons, due to the differential movement of the left and right ailerons, that is, the aileron on one side moves upward and the aileron on the other side moves downward, causing the lift at both ends of the wing to change. A pressure difference is generated, and the lift of the raised end of the aileron is less than the lift of the lowered end of the aileron. This provides the power for the aircraft to roll left and right.

Supplement 1: On modern aircraft, the left and right ailerons have a mixed control function. They no longer perform differential motion alone. They can be differential, the same up and down, or the same up and down but on both sides. The swing angles are different, so that in some special circumstances, the ailerons of the wing can function as an elevator like a horizontal tail; sometimes they also provide a flap function to increase lift.

Supplement 2: In the model, the model helicopter also has ailerons, and the function is relatively complicated, so I won’t go into details. However, as the trend develops, helicopter models without ailerons will gradually replace helicopter models with ailerons, and all stunts will be realized through the mixing control of the main rotor and the cooperation of the tail rotor.

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