03/31/2008. Remarks by Walter van Tilborg: "The aircraft was an original design by Alvin Schubert of Galesville, Wisconsin and the one-of-a-kind airplane was first flown during 1978, fitted with a 35 hp VW1200 engine.

By the time Der Fledermaus (The Bat) was pictured in 1980, the engine had been replaced by a 55 hp VW1600, while also the engine cowling, cockpit canopy, landing gear and paint scheme had been altered."