Air Transport Services Group, Inc. (ATSG), along with its various subsidiaries, operates both domestically within the United States and on an international scale, primarily focusing on aircraft leasing, air cargo transportation, and a wide array of associated support services. Within the aviation sector, its services are extensive, covering aircraft provision, professional flight crews, aviation fuel supply, and aircraft hull and liability insurance. Furthermore, ATSG performs thorough aircraft maintenance and modification work, which includes airframe alterations, heavy overhauls, component repairs, specialized engineering services, and routine line maintenance.