The 517th Air Defense Group is a disbanded United States Air Force organization. Its last assignment was with the 4711th Air Defense Wing at Ethan Allen Air Force Base, Vermont. It was inactivated on 18 August 1955. The group was originally activated as a support unit for a bombardment group group at the end of World War II in Italy and then redeployed to the Caribbean, where it supported units redeploying from Europe until it was inactivated in 1945. The group was activated once again in 1953, when ADC established it as the headquarters for a dispersed fighter-interceptor squadron and the medical, maintenance, and administrative squadrons supporting it. It was replaced in 1955 when ADC transferred its mission, equipment, and personnel to the 14th Fighter Group in a project that replaced a