Photograph:
Stephens Sea Hawk Mk 4 at the ultralight museum at Holbrook, NSW (David C Eyre)
Country of origin:
Australia
Description:
Single-seat light single-engine amphibian
Power Plant:
Two 16 kw (22 hp) JPX two-cylinder, two-stroke, air-cooled engines
Specifications:
- Rate of climb: 305 m/min (1,000 ft/min)
- Landing speed: 56 km/h (35 mph)
- Empty weight: 150 kg (331 lb)
- Loaded weight: 300 kg (661 lb)
History:
The Sea Hawk was designed by Mr J Stevens in Queensland for the ultralight amateur-built market and was the culmination of a number of designs he had produced and built over the years. Completed to meet 95.10 regulations, the first of his aircraft was built in 1977 and, known as the Mk I, was an experimental stick-insect type ultralight. His second aircraft, the Mk 2, was the first amphibian and was fitted with a single 16 kw (22 hp) JPX engine driving a two-blade metal propeller with a direct drive, having a floating arm undercarriage. The Mk 3 was a further development of the Mk 2; and the Mk 4 was the Mk 3 converted to take a 26 kw (35 hp) Mercury engine. This aircraft incorporated a full flying wing with no ailerons and had two mainwheels and a tail skid. It was flown for some 100 hours during testing. The Mk V was a new development and had a new fuselage attached to the wing of the Mk 4, the fuselage frame being Tig-welded 6063-T6 aluminium with stainless steel fittings and with fabric covering.
One Mk 4 appeared on the RAA ultralight register as 10-0006 (c/n 07), being registered on 21 February 1987, the registration expiring on 20 February 2010.