Hirth Hi 20 MoSe

Based on the Göppingen Gö 4 side-by-side seat training glider, it had a foldaway propeller, column-mounted above the fuselage and shaft-driven by a small internal piston engine.

The Schempp-Hirth factory at Nabern (now Kirchheim/Teck) was busy with the production of the Göppingen Gö 4 and with the outbreak of World War II, the sole prototype was not completed until 1941.

[3] Rather than develop a new aircraft for their foldaway power plant and propeller experiments, it was decided to save on time and money by using the wings and tail of a Göppingen Gö 4.

The propulsion unit, when deployed, consisted of a vertical, faired column carrying a pusher propeller with its hub about 700 mm (2 ft 4 in) above the fuselage, so the tips just cleared the structure.

After a powered climb to altitude, the unit was rotated on its pivot so the propeller fitted into a dorsal slot in the fuselage and the engine lay immediately behind the cockpit bulkhead.