Photograph:
Rotorway Scorpion at the RAAFA Aviation Heritage Museum at Bull Creek, WA in October 2012 (David C Eyre)
Country of origin:
United States of America
Description:
Two-seat light sport helicopter
Power Plant:
One 99 kw (133 hp) RW-133 four-cylinder horizontally-opposed liquid-cooled engine
Specifications:
- Main rotor diameter: 7.62 m (25 ft)
- Length: 6.24 m (20 ft 6 in)
- Height: 2.22 m (7 ft 3 in)
- Tail rotor diameter: 1.06 m (3 ft 6 in)
- Max speed: 145 km/h (90 mph)
- Cruising speed: 129 km/h (80 mph)
- Rate of climb: 244 m/min (800 ft/min)
- Hovering ceiling in ground effect: 1,981 m (6,500 ft)
- Service ceiling: 3,048 m (10,000 ft)
- Range: 193 km (120 miles)
- Empty weight: 358 kg (790 lb)
- Useful load: 191 kg (420 lb)
- Loaded weight: 553 kg (1,220 lb)
History:
The Schramm Aircraft Company was formed in 1958 by B J Schramm to market both ready-to-fly and pre-fabricated components for single-seat light sporting helicopters. Initially the Company tried a number of power plants suitable to install in its helicopters, including Mercury, Evinrude and Volkswagen units. Eventually Schramm designed his own engine.
The Scorpion was one of a number of light helicopter designs produced by BJ Schramm in the United States as “the ultimate transportation/recreational vehicle for the homebuilder.” His first design, the Javelin, an open-cockpit single-seat helicopter, was produced in small numbers in kit form. The second of the designs to go into production was the Scorpion 133, powered by a 99 kw (133 hp) RW-133 liquid-cooled engine. The Scorpion was developed from the Javelin and, when in 1970 a two-cycle engine of 93 kw (125 hp) became available, this was installed. The machine became the Scorpion TOO with a max take-off weight of 510 kg (1,125 lb).
Later in 1975 Mr Schramm built the RW-133, a liquid-cooled engine of 133 cub-in displacement weighing 77 kg (170 lb), which provided 75 kw (100 hp) at 3,500 rpm. After demonstrations of the engine at Oshkosh in Wisconsin that year the Company, RotorWay Aircraft Inc of Tempe, Arizona commenced to market the Scorpion 133 as a construction package direct from the factory. The Company also set up a flight-training facility and buyers of the kit attended a seminar about the machine, a pre-construction ground school course, followed by flight training. A Scorpion 133 built from a kit won the Grand Champion Rotorcraft Award.
A number were built as kits in the United States, one (N81896) being fitted with a Rajay Model 377 H 40 turbocharger and a model 2110 Holley two-barrel carburettor. Scorpions are known to have been imported to Australia but the number is not known. One was imported for static display purposes by the provisional RotorWay distributor but, due to the financial troubles of the parent company in the United States, very few were obtained. Intended to launch the new Australian company in Western Australia, this machine was put into storage until offered for sale in January 1997. Later it was placed on display at the RAAFA Aviation Heritage Museum at Bull Creek, WA. One is known to have been imported to New Zealand but its fate is not known.