Retired 1948 Manufacturer Yakovlev | First flight 1947 | |
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.
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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 unit with twin endplate 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 gearbox supported the Rotor pylon which had two, contra-rotating, co-axial, two-bladed rotors. A fixed tricycle undercarriage mounted on steel tube trusses supported the helicopter on the ground. Flight testing revealed vibration at forward speeds 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 8 July 1948.