Which primary flight control surface is primarily responsible for roll control?

• A. Aileron
• B. Elevator
• C. Rudder
• D. Trim Systems

Answer: (A)

Roll is rotation around the aircraft’s front-to-back axis. The ailerons are the primary control surfaces that cause this motion. They are on the trailing edges of the wings and move in opposite directions: one wing’s aileron goes up while the other goes down. This creates differential lift—lifting the wing with the down-deflected aileron and reducing lift on the wing with the up-deflected aileron—producing a rolling motion toward the lower wing. The elevator controls pitch (nose up or down) about the lateral axis, and the rudder controls yaw (nose left or right) about the vertical axis. Trim systems help maintain a steady attitude without producing the roll movement themselves.