Yakovlev EG
The Yakovlev EG (Eksperimentalnyi Gelikopter), most commonly known as the Yak-M11FR-1, was an experimental aircraft with coaxial rotors. The first Yakovlev prototype was assisted by Kamov and was tested in 1947 to 1948.
Design and development
The aircraft contained a side-by-side cockpit, tricycle-type landing gear, and a tailskid behind a tailplane with twin fins. The fuel tank was under the main gearbox while the oil tank was next to the engine. A fabric was added on rear fuselage of later prototypes to provide better stability in cruising flight. One prototype, designated Yak-Sh, proved that the tailskid and the tail structure itself caused problems in control. Because of this, the tail was reconfigured and the tailskid was removed. The tail was eventually an open frame without a tailplane. After this reconfiguration, the Sh had better control while hovering and flying at low speed. But in the progress of exceeding a higher speed of 30km/h, vibrations soon occurred in the fuselage and control was lost once again.
The Yak-EG design was dropped in 1948, not only because of problems with prototypes, but also because of the Mil Mi-1 proving to be a better light helicopter design for the Soviet Union. [1]
Specifications
- Engine: 140hp, M-11FR-1 5-cylinder air-cooled piston engine
- Rotor diameter: 10.0m
- Length: 6.53m
- Take-off weight: 1020kg
- Empty weight: 878kg
- Payload: 142kg
- Fuel: 50kg
- Max speed at sea level: 150km/h
- Max speed reached: 70km/h
- Hovering ceiling: 250m
- Service ceiling: 2700m
- Service ceiling reached: 180m
- Range: 235km
See also
Related development
References
Bill Gunston & Yefim Gordon "Yakovlev Aircraft since 1924", 1997
Bill Gunston "The Osprey Encyclopedia of Russian Aircraft", 2000
External links
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