The A-10 Thunderbolt II, also known as the Warthog, is a twin-engine aircraft that provides close-air support of ground forces and employs a wide variety of conventional munitions including general purpose bombs. The simple, effective and survivable single-seat aircraft can be used against all ground targets, including tanks and other armored vehicles. Boeing is under contract to manage production of a maximum of 112 wing sets and spare kits. The U.S. Air Force ordered 27 wing sets immediately at contract award. Under a previous contract, Boeing delivered 173 wing sets to the Air Force.