The Showers Skytwister Choppy is an American helicopter that was produced by Showers-Aero of Milton, Pennsylvania, introduced in 1992. Now out of production, when it was available the aircraft was supplied in the form of CAD plans for amateur construction.^[1][2]

Design and development

The Skytwister is a modernized and updated version of the Adams-Wilson Hobbycopter, also called the "Choppy", as redesigned by Ben Showers.^[1][2]

The Skytwister was designed to comply with the US Experimental - Amateur-built aircraft rules. It features a single main rotor, a two-bladed tail rotor, a single-seat open cockpit with a windshield and skid-type landing gear. The standard engine used is a twin cylinder, liquid-cooled, two-stroke, dual-ignition 64 hp (48 kW) Rotax 582 powerplant with a 2.58:1 reduction drive, which replaces the original Choppy's motorcycle engine.^[1]

The aircraft fuselage is made from bolted-together aluminum tubing. Its two-bladed Fleck 2706 aluminium alloy main rotor is made as an extrusion and has a 21.50 ft (6.6 m) diameter. The tail rotor has a diameter of 36 in (91.4 cm). The aircraft has an empty weight of 320 lb (145 kg) and a gross weight of 670 lb (304 kg), giving a useful load of 350 lb (159 kg). With full fuel of 5 U.S. gallons (19 L; 4.2 imp gal) the payload for pilot and baggage is 320 lb (145 kg).^[1]

The designer estimated the construction time from the supplied plans as 300 hours.^[1]

Operational history

By 1998, the company reported that 200 sets of plans had been sold and 12 aircraft were completed and flying.^[1]

By April 2015, no examples were registered in the United States with the Federal Aviation Administration, although a total of one had been registered at one time.^[3]

Specifications (Skytwister)

Data from Purdy and All-Aero^[1][2]

General characteristics

• Crew: one
• Length: 15 ft 8 in (4.78 m)
• Width: 5 ft 8 in (1.73 m)
• Height: 6 ft 8 in (2.03 m)
• Empty weight: 320 lb (145 kg)
• Gross weight: 670 lb (304 kg)
• Fuel capacity: 5 U.S. gallons (19 L; 4.2 imp gal)
• Powerplant: 1 × Rotax 582 twin cylinder, liquid-cooled, two stroke aircraft engine with a 2.58:1 reduction drive, 65 hp (48 kW)
• Main rotor diameter: 21 ft 6 in (6.55 m)
• Main rotor area: 363 sq ft (33.7 m²)

Performance

• Maximum speed: 85 mph (137 km/h, 74 kn)
• Cruise speed: 65 mph (105 km/h, 56 kn)
• Rate of climb: 1,000 ft/min (5.1 m/s)
• Disk loading: 1.8 lb/sq ft (8.8 kg/m²)

See also

• List of rotorcraft

References

External links

• Photo of the Skytwister