The planar surface of a heavier-than-air body whose primary purpose is to produce lift during flight. A wing is composed of a series of airfoil-shaped components joined together to form one integral structure. On an airplane, the wing also provides storage space for the fuel and undercarriage, and is often used as the structural anchor point for the propulsion systems. The wing also includes important flight-control surfaces, such as the aileron, flaps, slats, and spoilers.