The 839th Air Division is an inactive United States Air Force organization. Its last assignment was with Military Airlift Command, assigned to Twenty-First Air Force at Sewart Air Force Base, Tennessee, although except for the last month of its existence it was assigned to Tactical Air Command. It was inactivated on 31 December 1974.

The Twenty-First Air Force is an inactive numbered air force of the United States Air Force. It was last active as the 21st Expeditionary Mobility Task Force, stationed at the McGuire AFB entity of Joint Base McGuire–Dix–Lakehurst until its inactivation in 2012. In this capacity, it was subordinate to Air Mobility Command's Eighteenth Air Force.