Not a typical leading-edge device type?

• A. Movable slats
• B. Fixed slots
• C. Leading edge flaps
• D. Ailerons

Answer: (D)

Leading-edge devices change the shape or gap at the front of the wing to keep the airflow attached and increase lift, especially at high angles of attack. Movable slats extend from the leading edge to create a slot-like effect, fixed slots are openings that allow high-energy air to re-energize the airflow, and leading-edge flaps increase camber for more lift during takeoff and landing. Ailerons, however, are located on the trailing edge and are used to roll the aircraft by differential lift between the wings, not to modify the leading-edge flow. So the surface that isn’t a typical leading-edge device is the one that controls roll rather than augmenting lift through the leading edge.