The Goppingen Go 9 was an experimental aircraft designed to test the rear propulsion system for the Dornier Do 335.
After Claudius Dornier patented the idea of a twin engine aircraft using an engine at each end of the fuselage, it was decided to build a small aircraft to test the idea's feasability. Designed by Doctor Ulrich Hüter and built at the Schempp-Hirth glider factory at Wüsterburg, the test aircraft was designated as the Göppingen Gö 9, and registered D-EBYW. The resulting machine was a small aircraft, with a single 80 hp Hirth HM 60R engine mounted behind the cockpit. This drove a four bladed pusher propeller by means of an extension shaft.
Other than the propulsion method, the Göppingen Gö 9 had a very normal layout. The aircraft was basically identical to the Dornier Do 17, except the dimensions were reduced by 1:2.5. The fuselage was cylindrical, with the wings being mounted midfuselage. A cruciform tail unit was designed, with the bottom fin being supplied with a small wheel which acted as a tail bumper to keep the rear propeller from striking the ground on takeoff. The pilot sat in a cockpit located in the front of the aircraft, and the extreme nose was glassed in. One advanced feature for this small testbed was a fully retractable tricycle landing gear system.
The Göppingen Gö 9 was extensively tested on the ground before it was taken into the air. The first test flights were made in early 1940, with the Go 9 towed into the air by a Dornier Do 17 medium bomber. With Dornier test pilot Quenzler at the controls, the Göppingen Gö 9 handled well, and proved the feasibility of the rear engine concept. Many more test flights were made, and the tiny Göppingen Gö 9 even took off on its own power. The ultimate fate of this interesting test aircraft is unknown.
The engine configuration was lated used in the Douglas XB-42
There are three commercially available resin scale models of the Go 9 - a pair of 1/72 scales models from Blitz and CzechMaster (CMK), and a 1/48 scale model from Lumir Vesely.