High Quality Content by WIKIPEDIA articles! The Ling-Temco-Vought A-7 Corsair II is a carrier-based subsonic light attack aircraft introduced to replace the United States Navy`s Douglas A-4 Skyhawk, initially entering service during the Vietnam War. The Corsair II was later adopted by the United States Air Force, to include the Air National Guard, to replace the Douglas A-1 Skyraider, North American F-100 Super Sabre and Republic F-105 Thunderchief. The aircraft was also exported to Greece in the 1970s, and Portugal and Thailand in the late 1980s. The A-7 airframe design was based on the successful supersonic Vought F-8 Crusader. It was one of the first combat aircraft to feature a head-up display (HUD), an inertial navigation system (INS), and a turbofan engine.