Military Air Transport Service assumed responsibility for the strategic airlift mission previously carried out by the Air Transport Command (ATC), transporting cargo and personnel to destinations within the Pacific and the Continental United States. It organized the 531st Air Transport Group (ATG) at Hickam to replace ATC's 1521st Air Force Base Unit (Air Transport). The group was initially equipped with three squadrons of C-54 Skymasters that could reach the Continental US, but required intermediate stopovers along the Pacific transport routes to stations as far away as Pakistan. The unit also had association with Naval Air Transport squadrons assigned to Hickam as part of the joint service organization of MATS. The group was a tenant organization at Hickam, which was a Pacific Air Comman