Lineage. Constituted as USAF Hospital, Osan, on 12 May 1971. Activated on 17 May 1971. Redesignated as 51 Medical Group on 15 Sep 1987. Assignments. 6314 Support Wing, 17 May 1971; 51 Air Base (later, 51 Composite, [Tactical]; 51 Tactical Fighter; 51 Wing; 51 Fighter) Wing, 1 Nov