Baumgärtl Heliofly III explained

The Baumgärtl Heliofly III/57 and Baumgärtl Heliofly III/59 were 1940s experimental backpack helicopters designed and built by the Austrian-designer Paul Baumgärtl. Following on from his earlier experiments with strap-on autogyros the Heliofly III/57 was powered by two 80NaN0 Argus As 8 piston engines each driving a single-blade of the contra-rotating rotors.^[1]

A problem with the supply of the As 8 engine forced a re-design to use one 160NaN0 engine, powering two rotors on a common co-axial shaft, with the engine driving one rotor directly and the other through gearing to overcome the torque effects.^[1]

References

Bibliography

• Book: The Illustrated Encyclopedia of Aircraft (Part Work 1982-1985). Orbis Publishing.
• Nowarra, Heinz J.. Die Deutsche Luftruestung 1933-1945 - Vol.1 - AEG-Dornier. Bernard & Graefe Verlag. 1993. Koblenz. (Gesamtwek), (Band 1)

Notes and References

1. Nowarra, Heinz J.. Die Deutsche Luftruestung 1933-1945 - Vol.1 - AEG-Dornier. Bernard & Graefe Verlag. 1993. Koblenz. (Gesamtwek), (Band 1)