The LTV A-7 Corsair II was a light assault aircraft on the basis of the F-8 Crusader. The A-7 ended up being 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 United States Navy while the united states of america Air Force, and later with all the Air National Guard. It had been also exported to Southern Vietnam (through the Vietnam War), Greece (A-7H), Portugal(A-7P), and Thailand (within the belated 1980s)