Skycraft Scout

This Australian design was originally built by Ron Wheeler in 1972 as a powered version of his earlier Tweetie hang-glider design. First flown in May 1974, his friends asked him to build them one and by 1976 demand was so high Ron Wheeler set up Skycraft and full-scale production began in November 1976 after the issuing of the ANO 95.10. The stitching of catamaran sails is still evident in the wing of the very early models. The Scout, later dubbed Mk.1, was considerably cheaper than the other types available mainly because it is smaller and doesn’t offer quite the same performance. It is however more economical and resembles in many ways the very first microlight — the Santos Dumont Demoiselle of 1911. The single surface wire braced taildragger has three-axis control via the all flying tail “feathers and wing warping for roll control. Airframe is constructed from high tensile alloy section extruded from the com-pany’s dies. The aircraft sits high on the main wheels, an advantage for its rough strip capabilities. An engine option was available as well as floats and a cockpit pod, and optional Rotax 377 engine. The floats were designed by Wheeler and added to his aircraft in September 1977. The aircraft with floats was first displayed at the Schofield Air Show in 1978.

En route, it has gained a modified front axle and seat support (hence the Mk2 title) but otherwise it is little changed. The same 173cc Pixie Major engine is used, driving a tractor propeller, and controls are two-axis, operated entirely by the stick and with no separate roll control for the single-surface wing. The Scout Mk.2 was a single-seat single-engined high-wing monoplane with two-axis control. Wing has unswept leading edge, swept forward trailing edge and tapering chord; conventional tail. Pitch con-trol by fully flying tail; yaw control by fully flying rudder; no separate roll control. Con-trol inputs through stick for pitch/yaw. Wing braced from above by kingpost and cables, from below by cables; single-surface wing. Undercarriage has three wheels in taildragger formation; steel-spring suspension on main wheels. Push-right go-right tailwheel steering connected to yaw control. No brakes. Aluminium-tube framework, without pod. Engine mounted at wing height driving tractor propeller. Stainless-steel rigging and control cables. Wing material is heavy-duty Dacron.

The combination of very small fuel tank and low maximum speed means that the Scout is more of a fine-weather fun machine than an aircraft for cross-country flying. Nevertheless the Scout has won many friends in its seven years of flying, not least because of its 15 minute rigging time, and has earned its place in the history of the sport.

The Scout Mk.3/3/R was a single-seat single-engined high-wing monoplane with conventional three-axis control. Wing has unswept leading edge, swept forward trailing edge and tapering chord; conventional tail. Pitch control by fully flying tail; yaw control by fully flying rudder; roll control by wing warping; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from above by kingpost and cables, from below by cables; single -surface. Undercarriage has three wheels in taildragger formation; steel-spring suspension on mail wheels. Push-right go-right tailwheel steering connected to yaw control. No brakes. Aluminium-tube framework, without pod. Engine mounted at wing height driving tractor propeller. Stainless-steel rigging and control cables. Wing material is heavy-duty Dacron. Introduced in 1982 to cater for pilots wanting conventional three-axis controls, the Scout Mk3/3/R uses a wing-warping system for roll control. Rudder pedals control yaw and also operate the steerable tailwheel. However, the adoption of three-axis control was not the only major change. The Pixie engine was discarded in favour of a 250 Robin, bringing a marked improvement in performance and giving rise to the 'R' in the designation title (the second '3' indicates three-axis). Typical output for a 250 Robin is 18 hp, but in this application 21 hp is claimed, using an exhaust system engineered specifically for this aircraft. There are also numerous detail engineering changes compared to the Mk2, plus a modified framework which gives better pilot protection.

While the wing-warping system has proved effective as a wing-levelling device, adverse yaw can be experienced under some circumstances and further modifications to eliminate this have been designed by one of Britain's Scout dealers as the Flylite (East Anglia) Super Scout.

 

 

 

 

 

                                             courtesy Steven walker

Gallery

Scout Mk.I
Engine: Pixie Major, 14hp at 6500rpm
Propeller diameter 48 inch, 1.23 m
V-belt reduction, ratio 3.0/1
Max static thrust 79 lb, 36 kg
Power per unit area 0.13 hp/sq.ft, 1.4hp/sq.m
Fuel capacity 0.6 US gal, 0.5 Imp gal, 2.5 litre
Length overall 17.1 ft, 5.20 m
Height overall 6.2ft, 1.90m
Wing span 28.8ft, 8.77 m
Chord at root 6.5ft, 1.98 m
Chord at tip 1.3ft, 0.40m
Sweepback 0 deg
Tailplane span 10.5ft, 3.2m
Rudder height 4.8 ft, 1.47 m
Total wing area 109 sq.ft, 10.1 sq.m
Total elevator area 12.5 sq.ft, 1.16 sq.m
Wing aspect ratio 17/1
Wheel track 4.5ft, 1.37m
Wheelbase 12.5ft, 3.80m
Tailwheel diameter overall 4 inch, 10cm
Main wheels diameter overall 12 inch, 31 cm
Empty weight 122 lb, 55.5 kg
Max take-off weight 297 lb, 135 kg
Payload 175 lb, 79.5 kg
Max wing loading 2.72 lb/sq.ft, 13.4 kg/sq.m
Max power loading 21.21b/hp, 9.65kg/hp
Load factors; >+3.0, >-3.0 ultimate
Max level speed 47 mph, 75 kph
Never exceed speed 75 mph, 120 kph
Max cruising speed 40 mph, 65 kph
Economic cruising speed 40 mph, 65 kph
Stalling speed 20 mph, 32 kph
Max climb rate at sea level 200ft/min, 1.0m/s
Min sink rate 510 ft/min at 40 mph, 2.6 m/s at 65 kph
Best glide ratio with power off 7/1 at 40 mph 65 kph
Take-off distance 230 ft, 70 m
Land-ing distance 100ft, 30m
Service ceiling 9900ft, 3000m
Range at average cruising speed 28 mile, 45 km

3/3/R
Engine: Robin EC25PS, 21 hp at 6500 rpm
Propeller diameter: 48 inch, 1.23 m
V-belt reduction, ratio 2.2/1
Max static thrust 130 lb, 59 kg
Power per unit area 0.19 hp/sq.ft, 2.1 hp/sq.m
Fuel capacity 1.6 US gal, 1.3 Imp gal, 6.0 litre
Empty weight 130lb, 59kg
Max take-off weight 310 lb, 141 kg
Payload 1180 lb, 82 kg
Max wing loading 2.84 lb/sq.ft, 14.0 kg/sq.m
Max power loading 14.8 lb/hp, 6.7 kg/hp
Load factors design; >+3.0, >-3.0 ultimate
Max level speed 53 mph, 85 kph
Never exceed speed 75 mph, 120 kph
Max cruising speed 47 mph, 75 kph
Economic cruising speed 47 mph, 75 kph
Stalling speed 20 mph, 32 kph
Max climb rate at sea level 550 ft/min, 2.8 m/s
Min sink rate 470 ft/min at 40 mph, 2.4 m/s at 65 kph
Best glide ratio with power off: 7/1 at 40 mph, 65 kph
Take-off distance 130 ft, 40 m
Land-ing distance 100ft, 30m
Service ceiling 9900ft, 3000m
Range at average cruising speed 56 mile, 90 km