The A-10 Thunderbolt II is a single-seat, twin-engine jet aircraft designed to provide close atmosphere support (CAS) of ground forces by attacking tanks, armored automobiles, alongside ground objectives. As a second mission, it gives airborne forward air control, leading other aircraft against ground targets. It's the very first US Air Force aircraft created exclusively for CAS. A -10A : Single-seat close atmosphere support,ground-attack variation.