Side-by-side two-seat single-engined high-wing monoplane with conventional three-axis control. Wing has swept back leading edge, swept forward trailing edge and tapering chord; conventional tail. Pitch control by fully flying tail; yaw control by fin-mounted rudder; roll control by spoilerons; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from below by struts; Wing profile 100% double-surface. Undercar-riage has three wheels in tricycle formation; glassfibre/carbon-fibre suspension on all wheels. Push-right go-right nosewheel steering connected to yaw control. Glassfibre fuselage, partially enclosed. Engine mounted below wing driving pusher propeller. Aircraft quality materials are used for all structural and control fittings. The wing and tail are of composite construction.
The Duet was conceived by two professional aircraft designers, Dave Kent and Brian Cunnington, as a rugged composite construction machine for touring, training and commercial uses. Their company, Designability Ltd., is a design consultancy and not a manufacturer, so having built and test flown their first 430cc Cuyuna engined prototype in July 1982, they found a buyer for the manufacturing rights.
Graham Andrews had just set up the company in conjunction with Barney Jordan and the two were looking for a suitable design when the Duct came on the scene. Since becoming the Jordan rather than the Designability Duet, the aircraft has under-gone extensive development, particularly as regards power plant. The Cuyuna was re-jected as not powerful enough and the big Rotax was substituted. This, coupled to a reduction drive and three-blade propeller, gives greatly improved performance and allows the aircraft to be flown safely in conditions which might ground other micro-lights; it can easily take-off and land in a 12 mph (19 kph) crosswind, for example.
The concept of the design, however, remains the same - a practical machine with 15 min rigging time from a trailer and suspension supple enough to allow it to cope with difficult fields. For pilot protection, a strong angled strut is mounted in front of the cockpit.
The prototype was designed to the same airworthiness standards as heavier aircraft. A second prototype, a pre-production model, was flying in March 1983, dual rudder pedals will be fitted.
Engine: Rotax 503, 45 hp at 6500 rpm.
Propeller diameter 46 inch, 1.16m (3-blade).
Belt reduction, ratio 2.0/1.
Max static thrust 250 lb, 113 kg.
Power per unit area 0.28 hp/sq.ft 11 hp/sq.m.
Fuel capacity 6.0 US gal, 5.0 Imp gal, 22.7 litre.
overall 22.0 ft, 6.71 m.
Height overall 5.5ft, 1.68m.
Wing span 36.0ft, 10.97m.
Chord at root 6.0ft, 1.83m.
Chord at tip 3.0ft, 0.91m.
Dihedral 3 deg.
Sweepback 0 deg.
Tailplane span 10.0ft, 3.05m.
height 4.0 ft, 1.22 m.
Total wing area 162 sq.ft, 15.1 sq.m.
Fin and rudder area: 11.0 sq.ft, 1.02 sq.m.
Total elevator area 26.6 sq.ft, 2.47 sq.m.
Wing aspect ratio 8.0/1.
Wheel track 6.0 ft, 1.83 m.
Wheelbase 6.0 ft, 1.83 m.
Nosewheel diameter overall 10 inch, 254 mm.
Main wheels diameter overall 15 inch, 381 mm.
Empty weight 320 lb, 145kg.
Max take-off weight 750 lb, 340kg.
Payload 430 lb, 195kg.
Max wing loading 4.63 lb/sq.ft, 22.6kg/sq.m.
Max power loading 16.6 lb/hp, 7.4kg/hp.
Load factors +4.4, -2.2 design; +6.6, -3.3 ulti-mate.
Max level speed 70 mph, 113 kph.
Never exceed speed 90 mph, 145 kph.
Max cruising speed 60 mph, 97 kph.
Economic cruising speed 50 mph, 80 kph.
Stalling speed 28 mph, 45 kph.
Max climb rate at sea level 480 ft/min, 2.4 m/s.
Min sink rate 350 ft/min at 40 mph, 1.8 m/s at 64 kph.
Best glide ratio with power off 12/1 at 45 mph, 72kph.
Take-off distance on tarmac 150ft, 45 m.
Landing distance 120ft, 35 m.
Service ceiling > 10,000 ft, >3050 m.
Range at average cruising speed 115 mile, 185km.