Mil Mi-1 piloted by Tatiana Roussian beat the altitude record (27 March 1959)

4 140 m World record with a piston engine
www.fai.org/re...
The Mil Mi-1 (NATO reporting name "Hare") was a Soviet three- or four-seat light utility helicopter. It was the first Soviet helicopter to enter serial production. It entered service in 1950
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footage from British Pathé