The 4th Air Division (4th AD) is an inactive United States Air Force unit. Its last assignment was with Fifteenth Air Force, stationed at Francis E. Warren AFB, Wyoming. It was inactivated on 23 August 1988. As the 4th Bombardment Wing, the unit was one of the primary B-17 Flying Fortress heavy strategic bombardment wings of VIII Bomber Command and later, Eighth Air Force in World War II. During the Cold War, the 4th AD was an intermediate command echelon of Strategic Air Command, controlling strategic bombardment and intercontinental strategic missile wings until inactivated in 1988.