However, demobilization was in full swing and few of these groups were fully equipped or manned. All of these groups were equipped with B-29 Superfortresses, most or all of which were aircraft which returned from Twentieth Air Force groups returning from the Pacific War. When SAC was established in 1946, its primary bomber aircraft was the B-29. Although there were many in storage, they were war-weary. The plane was greatly improved and soon new models, designated the B-50 Superfortress, began joining the inventory replacing the older aircraft.