An airplane flap is a movable part of an aircraft's wing that helps to control the lift and drag of the plane. Ailerons are the two flaps located at the trailing edge of the wings, which can be moved in opposite directions to create a rolling motion. An AILERON is a single flap located at the trailing edge of the wing. Elevons are flaps located at the trailing edge of the wings that can be moved in unison to control both the pitch and roll of the aircraft. Finally, a LAPEL is a single flap located at the leading edge of the wing.