During World War II, William Bushnell Stout was employed by Packard in 1917 when he was appointed as a technical advisor to the War production board. The board gave Stout a contract to develop a blended wing body aircraft. Funded by the Motor Products Corporation, Stout developed the "batwing" aircraft with the intent to market the aircraft to the United States Army. Stout first experimented with an all-wood flying wing design with a glider design, the "Batwing Glider", tested at Ford Airport in 1926. Stouts design was nicknamed "Bushnell's Turtle". (a reference to the unrelated David Bushnell's Turtle submarine's shape).
The blended-wing batwing was designed to have all surfaces of an aircraft used to provide lift, eliminating the added drag of a conventional fuselage. This concept is applied to all flying wind aircraft. The batwing differed slightly with the addition of a set of horizontal stabilizers at the rear of the aircraft for stability.
The aircraft was an early example of wood-veneer aircraft construction. The wings were covered with a 3 ply wood veneer only 1/20th of an inch thick. The internal bracing consisted of hundreds of spruce struts. Nine spars tested to 1 ton of load each.
To reduce drag, the aircraft employed a cantilever wing without support wires or struts. This required a "thick" wing to build a spar strong enough to support the aircraft. To maintain the shape of the wing, the chord also had to be longer as the wing became thicker. In the case of the batwing, the chord was the entire length of the aircraft. Since the spar did not need to be as thick toward the tips to support the load, the chord decreased further out along the wing, forming a oval shaped wing. As ideal as this was, it caused significant engineering challenges maintaining the center of pressure on the aircraft. Further aerodynamic drag reductions came from having the water cooled engine embedded into the wing with retractable radiators.
The pilot sat in an open cockpit placed at the top of the aircraft. Visibility was restricted downward by the placement. The batwing was the first example of a cantilevered wing and veneer skin in the United States.
The mockup of his first thick winged aircraft design was built at the Widman woodworking plant in Detroit, Michigan. The 150 hp engine was acquired from Charles Warren Nash who had a budding interest in the project. The first flight was in Dayton, Ohio in 1918. The pump shaft on the engine was broken, but the plane was flown anyway. Although the flight was successful, the test pilot Jimmie Johnson commented that the aircraft was too dangerous to fly because of the limited visibility. Stout later called the visibility "abominable". The test aircraft was put into storage. Soon afterward, Stout submitted British patent #149,708, with a batwing aircraft with the corners squared off rather than the oval design of the prototype. The updated aircraft was never produced. Stout went on to focus on more conventional aircraft featuring the advancement of all-metal construction, but continued to maintain the plane of the future will look like the batwing.
Stout drew plans for a scaled up version of the Batwing, with a 100 foot wingspan. The larger aircraft would have solved the visibility issues, but did not get past planning stages.
Stout also used the term "batwing" in the name of future aircraft that used cantilever wings.
Engine: 1 × Hispano -Suiza , 150 hp (110 kW)
Wingspan: 20 ft (6.1 m)
Wing area: 480 sq ft (45 m2)
Empty weight: 1,542 lb (699 kg)