321st Fighter Squadron

321st Fighter-Interceptor Squadron
321st Fighter-Interceptor Squadron F-89J Scorpions. 1956, Paine Air Force Base, Washington
Active	1942–1944; 1955–1960
Country	United States
Branch	United States Air Force
Role	Fighter-Interceptor
Insignia
Patch with 321st Fighter-Interceptor Squadron emblem (approved 9 January 1943)

The 321st Fighter-Interceptor Squadron is an inactive United States Air Force unit. Its last assignment was with the 316th Air Division, stationed at Paine Air Force Base, Washington. It was inactivated on 8 March 1960.

The 321st Fighter Squadron was activated at Mitchel Field, New York in August 1942 as one of the original squadrons of the 326th Fighter Group and moved the next month to Bradley Field, Connecticut and equipped with Republic P-47 Thunderbolts. The 321st performed the air defense mission for First Air Force in the northeast during 1942 and 1943 while also conducting operational training. Operational training units were oversized parent units which provided cadres to "satellite groups."

It later became a replacement training unit, remaining an oversized unit, but preparing individual pilots for combat duty in the Thunderbolt. In October 1943, the 326th Group provided the cadre to form the 402d Fighter Group. The 321st then moved to Seymour Johnson Field, North Carolina, along with the group headquarters and the other group squadron (the 322d) stationed at Westover Field, Massachusetts.

However, the Army Air Forces was finding that standard military units, based on relatively inflexible tables of organization were proving not well adapted to the training mission. Accordingly, it adopted a more functional system in which each of its bases was organized into a separate numbered unit. As a result, in 1944 the squadron was disbanded as the AAF converted to the AAF Base Unit system. The 123d AAF Base Unit (Replacement Training Unit, Fighter) replaced the group headquarters and squadrons at Seymour Johnson.