21st Troop Carrier Squadron, Medium

Constituted as 21 Transport Squadron on 7 Mar 1942. Activated on 3 Apr 1942. Redesignated as 21 Troop Carrier Squadron on 5 Jul 1942. Inactivated on 31 Jan 1946. Activated on 15 Oct 1946. Redesignated as: 21 Troop Carrier Squadron, Heavy, on 21 May 1948; 21 Troop Carrier Squadron, Medium, on 2 Feb 1951; 21 Troop Carrier Squadron, Heavy, on 1 Dec 1952; 21 Troop Carrier Squadron, Medium, on 18 Sep 1956; 21 Troop Carrier Squadron on 8 Dec 1966; 21 Tactical Airlift Squadron on 1 Aug 1967; 21 Airlift Squadron on 1 Apr 1992-.