Photograph:
Harmon Rocket II ZK-RMD (c/n HR2-187-08) at Paunaui, New Zealand in January 2019 (Richard Currie – NZCIVAIR)
Country of origin:
United States of America
Description:
Two-seat sport monoplane
Power Plant:
One (250 hp) Lycoming IO-540-c4b5 six-cylinder horizontally-opposed air-cooled engine
Specifications:
- Wingspan: 6.67 m (21 ft 10 in)
- Length: 6.55 m (21 ft 6 in)
- Height: 1.67 m (5 ft 6 in)
- Wing area: 10.12 m² (109 sq ft)
- Never exceed speed: 443 km/h (275 mph)
- Cruising speed at 75% power: 370 km/h (230 mph)
- Economical cruising speed at 55% power: 346 km/h (215 mph)
- Rate of climb: 945 m/min (3,100 ft/min)
- Stalling speed: 89 km/h (55 mph)
- Fuel capacity: 159 litres (35 Imp gals)
- Endurance: 3 hrs
- Empty weight: 516 kg (1,138 lb)
- Useful load: 292 kg (643 lb)
- Loaded weight: 907 kg (2,000 lb)
History:
John Harmon in the United States designed a development of the Vans RV-4 known as the Rocket II, having previously designed and built the Rocket I, which was a modified RV-3, it being a single-seat, low-wing, all-metal, light aircraft which could fly at 322 km/h (200 mph) on 112 kw (150 hp), this aircraft being known for its good handling and ability to use short dirt or grass runways.
This was followed by the Rocket II, which was based on the RV-4, seating two, and could be fitted with engines in the 93 kw to 134 kw (125 hp to 180 hp) range. It was not sold as a kit but Harmon sold a kit to modify the RV-4. It was capable of aerobatics and could operate from short and rough surfaces. The fuselage was changed from the RV-4 to add 10 cm (4 in) in width and 45.72 cm (18 in) in length. The wings were 38 cm (15 in) shorter. The undercarriage was built from titanium and the engine usually fitted by builders was the Lycoming O-540 unit.
A Harmon Rocket III was also produced based on the Vans RV-4 (N53HR) but in this case the fuselage was narrowed, had a single seat, and had shorter wings by 101.6 cm (40 in), also being powered by the Lycoming O-540 series engine.
A number of examples have been completed in this part of the world, the first in New Zealand becoming ZK-RMD (c/n HR2-187-08), followed by VH-TAB (c/n 342) and VH-AGN (c/n 119) in Australia.