Yakovlev EG

The Yakovlev EG (Eksperimentalnyi Gelikopter), also commonly known as the Yak-M11FR-1 and Sh (Shootka), was an experimental aircraft with coaxial rotors. The prototype was first flown by V.V. Tezavrovsky in December 1947.

Design and development

The fuselage of the EG was a welded steel tube truss with duralumin skinning on the fwd fuselage back to the rear of the engine compartment. The rear fuselage was fabric covered and supported a tailplane style with twin end-plate fins, as well as a tailskid. The Pilot and Passenger sat side by side under a glazed canopy with a car style door on each side. The M-11FR engine was mounted behind the gearbox which it drove via a short shaft. The gear box supported the Rotor pylon which had two, contra-rotating, co-axial, two-bladed rotors. A fixed tri-cycle undercarriage mounted on steel tube trusses supported the helicopter on the ground. Flight testing revealed vibration at forward spees above 20-30 km/h. In an effort to reduce vibration the tailplane and fins were removed. In early 1948 the M-11FR engine was replaced by an M-12, which proved troublesome so an M-11FR was refitted to complete the flight trials by 8th July 1948.^[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

• Yakovlev Yak-100
• Mil Mi-1
  

References

Yefim Gordon, Dmitry Komissarov & Sergey Komissarov "OKB Yakovlev" 2005

Bill Gunston & Yefim Gordon "Yakovlev Aircraft since 1924", 1997

Bill Gunston "The Osprey Encyclopedia of Russian Aircraft", 2000