Exhibit 21.1

Air Transport Services Group, Inc.

List of Significant Subsidiaries

December 31, 2017

1. ABX Air, Inc., a Delaware Corporation

2. Airborne Global Solutions, Inc., a Delaware Corporation

3. Airborne Maintenance and Engineering Services, Inc., a Delaware Corporation

4. Air Transport International, Inc., a Delaware Corporation

5. Air Transport International Limited Liability Company, a Nevada Limited Liability Company

6. AMES Material Services, Inc., an Ohio Corporation

7. Cargo Aircraft Management, Inc., a Florida Corporation

8. LGSTX Distribution Services, Inc., an Ohio Corporation

9. LGSTX Services, Inc., a Delaware Corporation

10. Pemco World Air Services Inc., a Delaware Corporation

11. ATSG West Leasing Limited, an Irish Limited Company