21. In the Soviet Union, Boris N. Yuriev and Alexei M. Cheremukhin, constructed and flew the TsAGI 1-EA single rotor helicopter, which used an open tubing framework, a four-blade main rotor, and twin sets of 1.8-meter (6-foot) diameter, two-bladed anti-torque rotors: one set of two at the nose and one set of two at the tail. Powered by two M-2 powerplants, up-rated copies of the Gnome Monosoupape rotary radial engine of World War I, the TsAGI 1-EA made several successful low altitude flights. By 14 August 1932, Cheremukhin managed to get the 1-EA up to an unofficial altitude of 605 meters (1,985 ft), shattering d'Ascanio's earlier achievement. As the Soviet Union was not yet a member of the FAI, however, Cheremukhin's record remained unrecognized.