Stewart S-51D Mustang
The Stewart S-51D Mustang is an American aerobatic homebuilt aircraft that was designed by Jim Stewart and produced by Stewart 51 of Vero Beach, Florida, introduced in 1994. When it was available the aircraft was supplied as a kit for amateur construction. The S-51D is a 70% scale version of the World War II P-51D Mustang fighter aircraft. Design and development. Designer Jim Stewart took a leave of absence from his employer, Pratt & Whitney, in 1989 to work on the S-51D's tooling and design. The prototype took flight on 30 March 1994 and by late June  had completed its 40 hours of test flying. The S-51D Mustang features a cantilever low-wing, a two-seats-in-tandem enclosed cockpit under a bubble canopy, retractable conventional landing gear, and a single engine in tractor configuration. The aircraft is made from sheet aluminum. Its span wing mounts flaps and has a wing area of . The cabin width is . The acceptable power range is . The specified propeller is a diameter, constant speed four-bladed Hartzell Propeller unit, that is driven by a spur gear with a (2.13:1) reduction ratio. The S-51D Mustang has a typical empty weight of and  a gross weight of , giving a useful load of . With full fuel of the payload for the pilot, passenger, and baggage is . The standard day, sea level, no wind, take off with a engine is and the landing roll is . The manufacturer estimated the construction time from the supplied standard kit as 2000 hours. A fast-build kit was also available. Operational history. By 1998 the company reported that 72 kits had been sold and two aircraft were completed and flying. In March 2014, 12 examples were registered in the United States with the Federal Aviation Administration, although a total  of 19 had been registered at one time.