Air Defense, Tactical Air Command (ADTAC) is an inactive unit of the United States Air Force, last stationed at Langley Air Force Base, Virginia. It was last assigned to Tactical Air Command, and was inactivated on 6 December 1985.It was a command and control organization responsible for the air defense of the United States.ADTAC was established when the Aerospace Defense Command (ADCOM) was inactivated as a Major Command on 1 October 1979.