A Douglas A-1 Skyraider taxis at a Tennessee air show and museum event. Powered by a Wright R-3350 radial engine, the rugged, heavily armed Skyraider served as the U.S. Air Force's primary attack and helicopter-escort aircraft over Southeast Asia, flying under callsigns such as "Sandy" and "Spad" in support of downed-airman rescue operations throughout the Vietnam War. Project: 219310