By 1930 the Soviet helicopter pioneers, Boris N. Yuriev and Alexei M. Cheremukhin, both employed by Tsentralniy Aerogidrodinamicheskiy Institut (TsAGI, the Central Aerohydrodynamic Institute), constructed one of the first practical single-lift rotor machines with their TsAGI 1-EA single rotor helicopter, powered by two Soviet-designed and built M-2 rotary engines, themselves up-rated copies of the Gnome Monosoupape rotary engine of World War I. The TsAGI 1-EA set an unofficial altitude record of 605 meters (1,985 ft) with Cheremukhin piloting it on 14 August 1932 on the power of its twinned M-2 rotary engines.[21]