Göppingen Gö 9
Encyclopedia
The Göppingen Gö 9 was a research aircraft built to investigate the practicalities of powering a plane using a pusher
Pusher configuration
In a craft with a pusher configuration the propeller are mounted behind their respective engine. According to Bill Gunston, a "pusher propeller" is one mounted behind engine so that drive shaft is in compression...
propeller
Propeller (aircraft)
Aircraft propellers or airscrews convert rotary motion from piston engines or turboprops to provide propulsive force. They may be fixed or variable pitch. Early aircraft propellers were carved by hand from solid or laminated wood with later propellers being constructed from metal...
located far from the engine and turned by a long driveshaft.
In 1937, Claudius Dornier
Claudius Dornier
Claude Honoré Desiré Dornier born in Kempten im Allgäu was a German airplane builder and founder of Dornier GmbH...
observed that adding extra engines and propellers to an aircraft in an attempt to increase speed would also attract a penalty of greater drag
Drag (physics)
In fluid dynamics, drag refers to forces which act on a solid object in the direction of the relative fluid flow velocity...
. He reasoned that this penalty could be minimized by mounting a second propeller at the rear of an aircraft. In order to prevent tail-heaviness, however, the engine would need to be mounted far ahead of it. Dornier patent
Patent
A patent is a form of intellectual property. It consists of a set of exclusive rights granted by a sovereign state to an inventor or their assignee for a limited period of time in exchange for the public disclosure of an invention....
ed this idea and commissioned a test plane to evaluate it.
The aircraft was designed by Dr Ulrich Hütter as a 40% sized, scaled-down version of the Dornier Do 17
Dornier Do 17
The Dornier Do 17, sometimes referred to as the Fliegender Bleistift , was a World War II German light bomber produced by Claudius Dornier's company, Dornier Flugzeugwerke...
and built by Schempp-Hirth
Schempp-Hirth
Schempp-Hirth Flugzeugbau GmbH is a glider manufacturer based in Kirchheim unter Teck, Germany.-History:Martin Schempp founded his own company in Göppingen in 1935, with the assistance of Wolf Hirth. The company was initially called "Sportflugzeugbau Göppingen Martin Schempp"...
. The airframe was entirely of wood, and power was supplied by a Hirth HM 60 mounted within the fuselage near the wings. Other than the engine installation, the only other unusual feature of the aircraft was its tail, which included a large ventral fin. This fin incorporated a small wheel that assisted in keeping the rear-mounted propeller away from the ground during take-off and landing. The Gö 9 carried the civil registration D-EBYW.
Initially towed aloft, flight tests began in June 1941, but later flights operated under its own power. The design validated Dornier's ideas, and he went ahead with his original plan to build a high-performance aircraft with propellers at the front and rear, producing the Dornier Do 335
Dornier Do 335
The Dornier Do 335 Pfeil was a World War II heavy fighter built by the Dornier company. The two-seater trainer version was also called Ameisenbär . The Pfeils performance was much better than other twin-engine designs due to its unique "push-pull" layout and the much lower drag of the in-line...
. The eventual fate of the Gö 9 is not known.