Photograph:
Hearn HA-2M Sportster – known as Parson Tandem gyrocopter – ZK-RAO3 (c/n 685) in 2005 (J Wood – NZCIVAIR)
Country of origin:
United States of America
Description:
Light sport gyrocopter
Power Plant:
One 97 kw (130 hp) Franklin Sport 4B four-cylinder horizontally-opposed air-cooled engine
Specifications:
- Rotor diameter: 8.53 m (28 ft)
- Length overall: 3.66 m (12 ft)
- Height: 2.34 m (7 ft 8 in)
- Rotor disc area: 57.18 m² (615.44 sq ft)
- Max speed at sea level: 145 km/h (90 mph)
- Max cruising speed at sea level: 121 km/h (75 mph)
- Economical cruising speed at sea level: 97 km/h (60 mph)
- Stalling speed: 45 km/h (28 mph)
- Rate of climb: 213 m/min (700 ft/min)
- Service ceiling: 2,440 m (8,000 ft)
- Range: 145 km (90 miles)
- Take-off run: 107 m (350 ft)
- Empty weight: 281 kg (620 lb)
- Loaded weight: 476 kg (1,050 lb)
History:
Developed by Martin Hollmann of Orlando, Florida, a senior design engineer in the aerospace industry, the HA-2M Sportster [also known as the Hollmann Sportster] was claimed to be the first two-seat gyroplane designed for the homebuilder who had access to a minimum of power tools. About 90 per cent of the structure was bolted and riveted together, and a minimum of machined parts was used. The Sportster was suitable for pilot training and for flying on short cross-country journeys. It was designed for towing behind a car for storage, with the rotor stowed in a box attached to the car’s roof. From the towed condition it was said it could be ready for its pre-flight walk-round inspection in ten minutes. It later became a two-seat gyrocopter produced in kit form by Winther Hollmann Inc of Cupertino, California in 1974.
Design work began in June 1969, and construction was started in December 1972 in Orlando. The gyrocopter was powered by a 97 kw (130 hp) Franklin Sport 4B flat-four engine and the prototype, registered N158, made its first flight in October 1974, receiving Federal Aviation Administration (FAA) certification in the Experimental Category. Test flying was completed by January 1976. The prototype won the ‘Best Original Design’ award at the Experimental Aircraft Association (EAA) Oshkosh, Wisconsin meeting and an ‘Outstanding New Design’ award at the Popular Rotorcraft Association (PRA) Fly-in at Rockford in Illinois. In 1977 it received the ‘Best Autogiro’ award at the EAA’s Annual Antique Fly-in and Air Show at Watsonville, California.
The Sportster had an enclosed cockpit, a pusher engine and a tricycle undercarriage. It utilised a collective pitch mechanism and a mechanical pre-rotator which engaged the engine, via a clutch, prior to take-off to pre-spin the rotor to 230 rpm. This allowed the aircraft to take-off after a very short run. A rotor brake was utilized to slow down the rotor after landing and to stop the blades for taxiing.
More than 65 Sportsters were constructed in the USA, Canada, New Zealand and Sweden, most of these being powered by a 112 kw (150 hp) Avco Lycoming 0-320 engine, but one owned by a Mr Grayson [living in Montana at a height of 6,500 ft (1,980 m)] was installed with a 119 kw (160 hp) Avco Lycoming engine and a larger rotor blade.
A few examples were imported to this region, including ZK-RAO (c/n RO8/1 or 685), but this machine was involved in an accident on 15 December 1979 at Palmerston North. Construction is known to have commenced on at least four others.