Lineage. Constituted 12 Pursuit Squadron (Interceptor) on 20 Nov 1940. Activated on 15 Jan 1941. Redesignated: 12 Fighter Squadron on 15 May 1942; 12 Fighter Squadron, Two Engine, on 26 Jan 1944; 12 Fighter Squadron, Single Engine, on 6 May 1946; 12 Fighter Squadron, Jet, on 23 Dec 1949; 12