In the Soviet Union, Boris N. Yuriev and Alexei M. Cheremukhin, two aeronautical engineers working at the "Tsentralniy Aerogidrodinamicheskiy Institut" (TsAGI or the Central Aerohydrodynamic Institute), constructed and flew the TsAGI 1-EA single lift-rotor helicopter, which used an open tubing framework, a four-blade main lift rotor, and twin sets of 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" 9 Type B-2 100 CV output rotary engine of World War I, the TsAGI 1-EA made several low altitude flights. By 14 August 1932, Cheremukhin managed to get the 1-EA up to an unofficial altitude of , shattering d'Ascanio's earlier achievement. As the Soviet Union was not yet a member of the FAI, however, Cheremukhin's record remained unrecognized.