The A-10 Thunderbolt II is a single-seat, twin-engine jet aircraft created to provide close environment help (CAS) of ground forces by attacking tanks, armored cars, with ground goals. As another goal, it provides airborne forward atmosphere control, leading other aircraft against ground objectives. Oahu is the first United States Air Force aircraft developed solely for CAS. A -10A : Single-seat close environment assistance,ground-attack variation.