KC-10 Extender Blackboard Art. The McDonnell Douglas KC-10 Extender is an aerial refueling tanker aircraft – the military version of the three-engined DC-10 airliner operated by the United States Air Force. The KC-10 was developed from the Advanced Tanker Cargo Aircraft Program. It incorporates military-specific equipment for its primary roles of transport and aerial refueling. It was developed to supplement the KC-135 Stratotanker following experiences in Southeast Asia and the Middle East. The KC-10 was the second McDonnell Douglas transport aircraft to be selected by the Air Force following the C-9. A total of 60 KC-10s were produced for the USAF. The Royal Netherlands Air Force operates two similar tankers designated KDC-10 that were converted from DC-10s.
