The 520th Air Defense Group is a disbanded United States Air Force organization. Its last assignment was with the 4706th Air Defense Wing at Truax Field, Wisconsin, where it was inactivated in 1955. The group was originally activated as a support unit for the 340th Bombardment Group at the end of World War II in Italy and then redeployed to the United States where it was inactivated in 1945. The group was activated once again in 1953, when ADC established it as the headquarters for a dispersed fighter-interceptorsquadron and the medical, maintenance, and administrative squadrons supporting it. It was replaced in 1955 when ADC transferred its mission, equipment, and personnel to the 327th Fighter Group in a project that replaced air defense groups commanding fighter squadrons with fighter groups with distinguished records during World War II.
History
World War II
The group was first activated during World War II in Italy in late 1944 as the 520th Air Service Group as part of a reorganization of Army Air Forces support groups in which the AAF replaced Service Groups that included personnel from other branches of the Army and supported two combat groups with Air Service Groups including only Air Corps units. Designed to support a single combat group. Its 946th Air Engineering Squadron provided maintenance that was beyond the capability of the combat group, its 770th Air Materiel Squadron handled all supply matters, and its Headquarters & Base Services Squadron provided other support. The group supported the 340th Bombardment Group in Italy. The group returned to the US and was inactivated in late 1945. It was disbanded in 1948.
During the Cold War, the group was reconstituted, redesignated as the 520th Air Defense Group, and activated at Truax Field in 1953 with responsibility for air defense of the Great Lakes area. It was assigned the 432d Fighter-Interceptor Squadron and 433d FIS, which were already stationed at Truax Field, as its operational components. The 432d FIS was flying North American F-86 Sabres, while the 433d FIS was flying Northrop F-89 Scorpions equipped with airborne intercept radar. Both squadrons had been assigned directly to the 31st Air Division. The group also replaced the 78th Air Base Squadron as the USAF host unit for Truax Field. It was assigned three squadrons to perform its support responsibilities. In March 1953, the 432d FIS converted to a later radar equipped and Mighty Mouse rocket armed model of the "Sabre". In July 1954, the 433d FIS moved to Alaska and was reassigned. The following month, the 456 FIS was activated to replace the 433d FIS. The 456th FIS was also equipped with "Sabres". The group was inactivated and replaced by the 327th Fighter Group as part of Air Defense Command's Project Arrow, which was designed to bring back on the active list the fighter units which had compiled memorable records in the two world wars. The group was disbanded once again in 1984.
Lineage
Constituted as 520th Air Service Group
Reconstituted and redesignated as 520th Air Defense Group on 21 January 1953
