The Douglas A-1 Skyraider, nicknamed 'Spad' by its crews, was a propeller-driven attack aircraft prized in Vietnam for its ability to loiter over target areas and absorb heavy battle damage. This close-up view of the aircraft's massive radial engine and four-blade propeller highlights the rugged design that made the Skyraider a favorite for close air support and search-and-rescue escort missions. Project: 218901