The A-10 Thunderbolt II is a single-seat, twin-engine jet aircraft designed to provide close air support (CAS) of ground forces by attacking tanks, armored vehicles, and other ground targets. As a secondary mission, it provides airborne forward air control, guiding other aircraft against ground targets. It is the first US Air Force aircraft designed exclusively for CAS. Night/Adverse Weather A-10 : Two-seat experimental prototype, for night and adverse weather work. Only one example was built.