Two YC-15 aircraft were built by McDonnell Douglas, now Boeing, as Advanced Medium STOL Transport prototypes with short takeoff and landing ability. The first flight took place on 26 Aug 1975, landing at Edwards AFB. The design pioneered the supercritical wing on a large aircraft, advanced the state of the art in airlift, could carry outsized vehicles, and could lift a 27,000-pound payload from a 2,000-foot runway. The prototype adapted a DC-10 cockpit, DC-8 nosewheel, and C-141 main landing gear. The aircraft here is the first one, number 70-1875, later fitted with a larger wing. Although the YC-15 was not produced in quantity, its traits appeared later in the C-17, which was mass-produced for the Air Force. Its dimensions and performance included a wingspan of 110 feet 4 inches and 132 feet 7 inches, a length of 124 feet 3 inches, a height of 43 feet 4 inches, a gross weight of 219,180 pounds, a cruising speed of 535 miles per hour, and Pratt and Whitney JT8D turbofan engines.