McDonnell-Douglas YC-15

The McDonnell Douglas YC-15 first prototype (72-1875), an advanced military STOL transport, made the type's maiden flight on 26 August 1975. Designed to contend against Boeing YC-14 prototypes for the USAF's advanced medium short take-off and landing transport (AMST) requirement, it had an externally-blown flap system that depended on the slipstream from four turbofan engines. The first flight was made three months ahead of schedule and the two YC-15 prototypes flew for three years before the test program ended.

YC-15
Engines: 4 x Pratt & Whitney JT-8D-17, 71.1kN
Max take-off weight: 68000 kg / 149915 lb
Wingspan: 33.6 m / 110 ft 3 in
Length: 37.9 m / 124 ft 4 in
Height: 13.2 m / 43 ft 4 in
Wing area: 161.7 sq.m / 1740.52 sq ft
Max. speed: 805 km/h / 500 mph
Range w/max.fuel: 4800 km / 2983 miles
Crew: 2-3

McDonnell Douglas YC-15