What causes a plane to roll?

The correct answer is based on the role of ailerons in controlling an aircraft's movement around its longitudinal axis, which is the axis that runs from the nose to the tail. Ailerons are located on the outer sections of the wings and work in opposition to each other; when one aileron is deflected upward, the other is deflected downward. This movement creates differential lift on the wings, causing one wing to rise while the other descends, resulting in a roll.

Roll is one of the three primary axes of aircraft movement, alongside pitch and yaw. While elevators control pitch by moving the nose of the aircraft up or down, and rudders manage yaw by turning the aircraft left or right, it is the ailerons that specifically enable the aircraft to roll. Flaps, on the other hand, serve to increase lift at lower speeds and do not contribute to controlling roll. Understanding the function of ailerons is essential for pilots as it is crucial for maneuvering and maintaining control during flight operations.