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RotorWay Scorpion



The Scorpion was the first real kit helicopter on the market that actually flew. It generated a tremendous amount of excitement in the aviation world. This was an experimental aircraft in the truest sense of the word, the company pioneering a concept of individual helicopter ownership and flight and making it a reality. It was not meant for the commercial market, but rather for the sport-flying public. While priced at $6,000, far more than the average car at the time, it still opened the possibility of individual helicopter ownership to a whole new audience. The greatest challenge was to design a helicopter that the average customer could actually build while providing the essential elements required for helicopter flight. When first introduced to the public it was an open-cabin single-seater.


Of all the systems available for propulsion, RotorWay chose what had proven to be one of the most efficient systems and paralleled the design also used on most light commercial helicopters at the time: a standard main rotor with a tail rotor to counteract the torque. Analyzing the pros and cons of three classical types of rotor hub systems (semi-rigid, rigid and fully articulated), RotorWay opted for the semi-rigid system for the Scorpion. In this system, the collective and cyclic controls were kept completely distinct by a patented system which used a flexible push-pull cable for control separation. All controls functioned with precision bearings and quality dampening devices.

This breakthrough in design, along with an extremely simplified rotor blade and off the shelf drivetrain components all served to make the RotorWay extremely simple in design, never sacrificing structural strength. This was RotorWay's constant objective. The original design, whose prototype was first flown in 1966, had very low life limits on major components. This was the main weakness that needed to be addressed with further research and development. With the help of consulting engineers, along with creative input and ideas from innovative customers, an improved version of the Scorpion was introduced in 1971. Among the improvements made were all-aluminum rotor blades, a 115 horsepower OMC 2-cycle engine (Evinrude Vulcan V-4 outboard motor) and a heavier drive system (shafts and bearings).


The Scorpion also utilized a system of v-belts to drive the tail rotor. This had a number of inherent safety features. First of all, the belts were not subject to torsional fatigue as in a long shaft. Secondly, the tail rotor drive gearbox overheating was eliminated. The result was that maintenance was both simplified and reduced.
Build time was approximately 600 hours with far more of the fabrication done by the builder than in the current model. It proved to be an extremely popular product and set the stage for even better things ahead.
Price 1982:  US$21,700.


Engine: 1 x Mercury, 47kW
Main rotor diameter: 5.85m
Max take-off weight: 272kg
Empty weight: 172kg
Max speed: 137km/h
Service ceiling: 3655m
Range: 257km

Engine 145-hp RotorWay
Gross Wt. 1250 lb
Empty Wt. 830 lb
Fuel capacity 10 USG
Rotor diameter 25 ft
Length 25 ft
Top speed 85mph
Cruise 65-70 mph
Climb rate 1200 fpm
Range 110 miles

Engine: Evinrude 14-cylinder outboard marine engine, 115 hp
Length: 17ft 1.25in
Rotor dia: 19 ft 6.5 in
Speed: 90 mph
Ceiling: 12,000 ft
Range: 105 miles
Seats: 1

Engine hp: 85 to 115 hp
Length: 17 ft
Height: 6 ft
Width (cab): 2 ft
Rotor dia: 19 ft
Empty weight: 375 lb
Gross weight: 700+ lb
Payload: 425+ lb
Disc loading: 2.2 lbs/sq.ft
Range: 160 miles
Speed (max): 95 mph
Speed (cruise): 65 mph
Service ceiling: 12,000 ft
Rate of climb: 900 ft/min



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