Wikipedia
Berger-Helicopter
Hans Berger, a noted Swiss inventor, formed Berger-Helicopter, to develop a series of light helicopters of his own design. The BX-50 of 1961 and the BX-110 of 1974 were built as prototypes, with the BX-110 proving sound enough to earn a certificate of airworthiness from the Swiss Board of Aviation. Besides these two machines, Berger's other inventions were a jet-powered car, and numerous other helicopter designs. Professionally, Berger was the sales representative for Brantly in Switzerland and Liechtenstein.