Lineage. Constituted as 393 Bombardment Squadron, Very Heavy, on 28 Feb 1944. Activated on 11 Mar 1944. Redesignated as: 393 Bombardment Squadron, Medium, on 2 Jul 1948; 393 Bombardment Squadron, Heavy, on 2 Apr 1966; 393 Bombardment Squadron, Medium, on 1 Dec 1969. Inactivated on 30 Sep 1990.