Bob Nelson under the front landing gear of a McDonnell-Douglas KC-10 'Extender'. ND Centennial Air Show at the old Hector Airport terminal, Saturday 8/19/1989.

KC-10 'Extender' is the military version of the three-engined DC-10 airliner operated by the USAF. 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. -wiki