Which control surface is used to control roll in an aircraft?

The ailerons are the primary control surfaces that manage roll in an aircraft. They are located on the outer wings and operate in opposition to each other; when one aileron is deflected upwards, the other is lowered. This differential movement changes the lift on each wing—decreasing lift on the wing with the upward aileron and increasing lift on the wing with the downward aileron—resulting in the aircraft rolling toward the wing with the lower lift. This capability is essential for maneuvering and maintaining control during turns.

In contrast, the elevators are responsible for pitch control, which affects the aircraft's nose angle relative to the horizon. The rudder is utilized to control yaw, which influences the aircraft's direction left or right around its vertical axis. Flaps, on the other hand, are primarily used to increase lift and drag during takeoff and landing, rather than for controlling roll.