Sterner Ultracraft Skywalker
Single-seat single-engined high-wing monoplane with conventional three-axis control. Wing has unswept leading and trailing edges, and constant chord; flaps fitted. Cruciform tail. Pitch control by elevator on tail; yaw control by fin-mounted rudder; roll control by ailerons; control inputs through stick for pitch/roll and pedals for yaw. Wing braced from below by struts; wing profile; double-surface. Undercarriage has three wheels in tricycle formation. Push-right go-right nosewheel steering connected to yaw control. Aluminium-tube framework, without pod. Engine mounted below wing driving pusher propeller.
In most respects the Sky Walker is a thoroughly conventional high-wing tube-and-Dacron machine, powered by the Cuyuna 430. Both the aircraft and its manufacturer made their debut in 1983 and, as is becoming common with recent ultralight designs of this type, strut bracing is employed rather than the kingpost-and-cable bracing which has been almost universal hitherto.
Quite the most unusual feature of the Sky Walker is its use of flaps. These lift-augmentation devices can be moved to four positions and at their maximum they reduce the stall speed by 3 mph (5 kph). Controls are conventional three-axis, with a side-mounted stick controlling the elevator and differential ailerons, and pedals controlling the rudder.
Price of the Sky Walker was $5495 in 1983.
Engine: Cuyuna 430, 30 hp at 6600 rpm
Propeller diameter and pitch 54 x 24 inch, 1.37 x 0.61 m
V-belt reduction, ratio 2.1/1
Power per unit area 0.21 hp/sq.ft, 2.3 hp/sq.m
Fuel capacity 5.0 US gal, 4.2 Imp gal, 18.9 litre
Length overall 18.0 ft, 5.49 m
Height overall 9.0ft, 2.74m
Wing span 32.0ft, 9.75m
Constant chord 4.4 ft, 1.33 m
Sweepback 0 deg
Total wing area 140 sq.ft, 13.0 sq.m
Wing aspect ratio 7.3/1
Empty weight 253 lb, 115kg
Max take-off weight 510 lb, 231kg
Payload 257 lb, 117kg
Max wing loading 3.64 lb/sq.ft, 17.8 kg/sq.m
Max power loading 17.0 lb/hp, 7.7kg/hp
Load factors; +5.0, -3.5 ultimate
Max level speed 62 mph, 100 kph
Never exceed speed 80 mph, 129 kph
Max cruising speed 62 mph, 100 kph
Economic cruising speed 50 mph, 80 kph
Stalling speed 24 mph, 39 kph (with flaps)
Stalling speed 21 mph, 34 kph (without flaps)
Max climb rate at sea level 600 ft/min, 3.1 m/s
Best glide ratio with power off 11/1