A U.S. Air Force A-1 Skyraider — nicknamed the 'Spad' for its rugged, propeller-driven design reminiscent of World War I fighters — taxis past a row of blast-protection revetments on a Vietnam air base flight line. Slow but heavily armed and able to absorb battle damage, the A-1 was prized by Air Commando and Special Operations squadrons for close air support and search-and-rescue escort missions throughout the Vietnam War. Project: 218938