McDonnell Douglas KC-10 Extender (1980-1990): The KC-10 Extender is the military version of the commercial DC-10 Series 30 convertible freighter. It was designed to carry a large cargo payload over long distances and also serve as an aerial refueling tanker. The KC-10 made its first flight on July 12, 1980. Fuel for aerial Refueling is carried in a large bladder cells in the bottom half of the fuselage, where baggage and cargo would be stored in a commercial DC-10. The upper half of the fuselage can accommodate up to 75 passengers, cargo on pallets, or open cargo such as jet engines. Cargo is loaded through a 102 inch by 140 inch door located on the left side of the forward fuselage. The KC-10’s ability to carry cargo as well as fuel permits fighter squadrons and their support equipment and personnel to be deployed by a single aircraft type, instead of requiring both a tanker and a cargo aircraft. The U.S. Air Force received 60 KC-10 Extender refueling tankers between 1980 and 1990.