The 520th Fighter-Interceptor Squadron is an inactive United States Air Force unit. Its last assignment was with 530th Air Defense Group, stationed at Geiger Field, Washington, where it was inactivated on 18 August 1955. The squadron was first activated during World War II as the 638th Bombardment Squadron, a dive bomber unit, but was disbanded before participating in combat in a general reorganization of Army Air Forces training units. It was reconstituted during the Cold War as a fighter interceptor unit supporting the air defense of the United States. History World War II The squadron was activated in April 1943 as the 638th Bombardment Squadron at Key Field, Mississippi, as one of the original squadrons of the 408th Bombardment Group. In August, along with several other Army Air Forces (AAF) single engine dive bomber units, it became a fighter-bomber unit, and was designated as the 520th Fighter-Bomber Squadron. The squadron did not receive aircraft to begin training until October, after it had moved to Drew Field, Florida. It served as an operational training unit with various aircraft, providing cadres to "satellite groups" and as a replacement training unit, training individual pilots. However, the AAF was finding that standard military units, based on relatively inflexible tables of organization, were not proving well adapted to the training mission. Accordingly, it adopted a more functional system in which each AAF base was organized into a separate numbered unit. In this reorganization the squadron was disbanded in 1944 as the AAF converted to the AAF Base Unit system and was replaced, along with other units at Woodward Army Air Field, by the 267th AAF Base Unit (Combat Crew Training Station, Fighter) in a reorganization of the AAF in which all units not programmed for deployment overseas were replaced by AAF Base Units to free up manpower for assignment overseas. Cold War air defense During the Cold War the squadron was reconstituted in December 1954. At this time, it was redesignated as the 520th Fighter-Interceptor Squadron and activated at Geiger Field, Washington, where it was assigned to the 530th Air Defense Group. At Geiger, the squadron flew airborne intercept radar equipped and Mighty Mouse rocket armed North American F-86D Sabre aircraft. The 530th Group was inactivated and replaced by the 84th Fighter Group (Air Defense) in 1955 as part of Air Defense Command's Project Arrow, which was designed to reestablish fighter units that had compiled