The Skyraider had a remarkably long and successful career; it became a piston-powered, propeller-driven anachronism in the jet age, and was nicknamed "Spad", after the French World War I fighter. It was operated by the United States Navy (USN), the United States Marine Corps (USMC), and the United States Air Force (USAF), and also saw service with the British Royal Navy, the French Air Force, the Republic of Vietnam Air Force (RVNAF), and others. It remained in U.S. service until the early 1970s. The low-wing monoplane design started with a Wright R-3350 Duplex-Cyclone radial engine which was later upgraded several times. Its distinctive feature was large straight wings with seven hard points apiece. The Skyraider possessed excellent low-speed maneuverability and carried a large amount of ordnance over a considerable combat radius. Further, it had a long loiter time for its size, compared to much heavier subsonic or supersonic jets. The aircraft was optimized for the ground-attack mission and was armored against ground fire in key locations, unlike faster fighters adapted to carry bombs, such as the Vought F4U Corsair or North American P-51 Mustang, which were retired by U.S. forces before the 1960s. Number built 3,180 For more details of the design and development, operational history and 39 variants, click here.