The LTV A-7 Corsair II was a light attack aircraft on the basis of the F-8 Crusader. The A-7 was one of the primary combat aircraft to feature a head-up display (HUD). doppler-bounded inertial navigation system, and a turbofan engine. It served with both the United States Navy while the usa Air Force, and soon after using the Air nationwide Guard. It was additionally exported to Southern Vietnam (through the Vietnam War), Greece (A-7H), Portugal(A-7P), and Thailand (inside belated 1980s)