User:BilCat/Sandbox/TsAGI 1-EA

The TsAGI 1-EA (ЦАГИ 1-ЭА) was a Soviet experimental single-rotor helicopter of the early 1930s.

Design and development
In the Soviet Union, Boris N. Yuriev and Alexei M. Cheremukhin, two aeronautical engineers working at the Central Aerohydrodynamic Institute (TsAGI) 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 1.8 m 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 605 m, shattering d'Ascanio's earlier achievement. As the Soviet Union was not yet a member of the FAI, however, Cheremukhin's record remained unrecognized.

The first successful attempt at a single-lift rotor helicopter design used a four-blade main rotor, as designed by Soviet aeronautical engineers Boris N. Yuriev and Alexei M. Cheremukhin, both working at the Tsentralniy Aerogidrodinamicheskiy Institut (TsAGI, the Central Aerohydrodynamic Institute) near Moscow in the early 1930s. Their TsAGI 1-EA helicopter was able to fly in low altitude testing in 1931–32, with Cheremukhin flying it as high as 605 meters (1,985 ft) by mid-August 1932.

The only previous successful attempt at a single-lift rotor helicopter, the Yuriev-Cheremukhin TsAGI-1EA in 1931 in the Soviet Union, used a pair of uprated, Russian-built Gnome Monosoupape rotary engines of 120 hp each for its power.