Flaps are which of the following?

• A. Fixed leading-edge device.
• B. Hinged portion of the trailing edge between the ailerons and fuselage. In some aircraft, flaps change lift and drag.
• C. Wingtip spoilers used for roll control.
• D. Ailerons used independently of flaps.

Answer: (B)

Flaps are movable surfaces on the trailing edge of the wing. They are hinged portions located along the inner part of the wing, usually between the fuselage and the ailerons. When extended, flaps increase the wing’s curvature and surface area, raising the lift coefficient at a given speed and also increasing drag. This enables lower takeoff and landing speeds. They are not fixed, not on the leading edge, and not the same as the ailerons, which control roll. So describing flaps as a hinged portion of the trailing edge between the ailerons and fuselage that can change lift and drag best captures their location and purpose.