Sun Aerospace Sunray
Single-seat single-engined monoplane with conventional three-axis control. Wing has swept back leading and trailing edges, and tapering chord; no tail, canard wing. Pitch control by elevator on canard; yaw control by fin-mounted rudders; control inputs through stick for pitch/roll and pedals for yaw. Retractable undercarriage has three wheels in tricycle formation. Ground steering by differential braking; (limited castoring nosewheel optional). Composite construction fuselage, partially enclosed (totally enclosed optional). Engine mounted level with centre part of wing driving pusher propeller.
Russ Mcdonald of Sun Aerospace announced that the test flights on the prototype, which is radical both in terms of its aerodynamics and the technology used, were under way from the end of March 1983 and the aircraft was scheduled to he shown in August at Oshkosh, where the Sun Ray will be in the running for the $10,000 prize offered by DuPont to promote the use of advanced materials and design concepts in lightweight aircraft construction.
The Sun Ray is a conventional control aircraft with a side-mounted control stick. Its wing has a laminar profile and is made up of two outer half-wings with a large dihedral and a central inverse-V wing forming the engine housing and carrying the pusher propeller. Below the joints between the centre section and the outer wings are twin parallel booms, which ensure the structural rigidity of the assembly by running forward to carry a canard at the nose of the fuselage, while above each joint is a fin and rudder assembly, inclined slightly outwards.
The fuselage forms the hull and has a float attached, adding to the buoyancy of the parallel twin booms, which act as under-wing floats. The single hull float and the outboard sponsons are detachable to take advantage of US law, which dictates that removable floats are not included in the empty weight of an ultralight. For ease of transportation, the outer wing and canard sections are removable, leaving a structure 8ft (2.4m) wide.
The Sunray makes extensive use of the Dupont fibre Kevlar, which is lighter and stronger than glass-fibre and which allows more elaborate shapes while giving an impeccable surface finish.
Engine: Kawasaki TA 440, 30 hp
Power per unit area 0.24hp/sq.ft, 2.6 hp/sq.m
Length overall 13.3 ft, 4.06 m
Height overall 6.0ft, 1.83m
Wing span 32.0ft, 9.75m
Canard span 8.0ft, 2.44 m
Total wing area 126 sq.ft, 11.7 sq.m
Empty weight 250 lb, 113kg
Max take-off weight 510 lb, 231kg
Payload 260 lb, 118kg
Max wing loading 4.05 lb/sq.ft, 19.7 kg/sq.m
Max power loading 17.0 lb/hp, 7.7kg/hp
Max level speed 63 mph, 101 kph
Never exceed speed 85 mph, 137 kph
Max cruising speed 56 mph, 90 kph
Economic cruising speed 43 mph, 69 kph
Stalling speed 27 mph, 43 kph
Max climb rate at sea level 600 ft/min, 3.1 m/s
Service ceiling 13,500ft, 4100m
Range at average cruising speed 145 mile, 233 km