...Air Transport Services Group, Inc. (ATSG) maintains a strong position as one of the world's leading providers of air cargo fleet leasing and related services, including crew, maintenance and insurance (CMI) services. ATSG's declining debt-to-EBITDA and debt-to-tangible net worth leverage measures highlight the company's strong earnings and cash flow and lower debt levels as it grows its fleet and base of revenues. These factors underscore ATSG's Ba1 corporate family rating. ATSG's earnings and cash flow have been more resilient than lessors of passenger aircraft due to the operating strength its cargo aircraft leasing business, particularly the leasing and CMI services associated with the time-definite package delivery network operations of key customers including Amazon.com, Inc. (A2 positive) and DHL (owned by Deutsche Post AG, A3 stable). ATSG's credit challenges include its high customer concentrations. In 2021, the US Department of Defense, Amazon, and DHL accounted for 31%, 30% and...