Lineage. Constituted as 1 Materiel Squadron, 23 Air Base Group (Reinforced), and activated, on 1 Sep 1940. Redesignated: 31 Materiel Squadron on 17 Jan 1941; 31 Service Squadron on 14 Jul 1942; 31 Air Service Squadron on 20 Aug 1943; 31 Engineering Squadron on 10 Nov 1944; 31 Air Engineering