Type 1-EA
Function experimental
Year 1930
Crew 1
Engines 2*120hp M-2
Length -
Rotor diameter 11.0m
Height -
Empty weight 982kg
Flight weight 1145kg
Ceiling 605m
Minimum Speed 0km/h
Maximum Speed 30km/h
360° turn -
Takeoff roll 0m
Landing Roll 0m
Flight Duration -
Range -
Armament none

1-EA by TsAGI, B.N.Yuriev/ A.M.Cheremukhin

Original TsAGI 1-EA. 18k b/w photo from the "History of aircraft construction in the USSR", Vol.2 p.414

Basic experimental helicopter with 4-blade main rotor and four small 2-blade anti-rotation propellers (with variable pitch),installed in pairs at the ends of fuselage. Flight testes began on June 26, 1932. In July-August 1-EA was demonstrated to M.N.Tukhachevskij and Ya.I.Alksnis.

M.N.Tukhachevskij suggested small series production, but A.M.Izakson (one of the designers) insisted that more development is needed and resources should not be dispersed on production of 'raw' machine.

Fuselage was simple frame made of steel tubes,its construction was optimized during tests. Original rectangular structure with tension wires was replaced by more solid triangular without wires.

TsAGI 1-EA with modified fuselage. 13k b/w photo from the "History of aircraft construction in the USSR" Vol.2, p.414

M-2 engines were selected because they did not require any special cooling in hovering regime. Because main rotor had solid blades, no special clutch was required and rotor started to spin once engines started (with compressed air).

On August 14, 1932 A.M.Cheremukhin reached altitude 605m. Unfortunately, The USSR at the time was not a member of an International Aviation Federation (plus secrecy, yes!), and this record could not be formally registered.

To conclude 1-EA story, it is necessary to mention that it was flown safely mostly due to well designed control system and pilot's skills of A.M.Cheremukhin. Simple straight link of main rotor to the power plant does not provide enough stability. Smallest variations in engine regime caused aircraft to move up or down, and required full attention of a pilot.

One built.

Modifications: 3-EA

Sources [6], Vol.2 p.414;

Modified March 24, 1997 Back to
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