McDonnell Douglas KC-10 Extender is an American tanker and cargo aircraft operated by the United States Air Force (USAF). A military version of the three-engine DC-10 airliner, the KC-10 was developed from the Advanced Tanker Cargo Aircraft Program.It incorporates military-specific equipment for its primary roles of aerial refueling and transport. It was developed to supplement the KC-135 Stratotanker following experiences in Southeast Asia and the Middle East.old livery are blue,white,gray