Ultralight Aviation Systems / UAS Storm Buggy
The Storm Buggy/ Flexiform Sky Sails Medium striker is a weight-shift single-seat/side-by-side two-seat single-en-gined flex-wing aircraft with weight-shift control. Rogallo Wing with keel pocket. Pilot suspended below wing in trike unit, using bar to control pitch and yaw/roll by altering relative positions of trike unit and wing. Wing braced from above by kingpost and cables, from below by cables; bowsprit construction with >70% double-surface; pre-formed ribs. Undercarriage has three wheels in tricycle formation; no suspension on any wheels. Push-right go-left nosewheel steering indepen-dent from yaw control. No brakes. Aluminium-tube trike unit, with optional pod. Engine mounted below wing driving pusher propeller.
Nick Wrigley's UAS com-pany was one of the pioneers of triking in Britain and produced the first ever two-seat trike unit, which it showed at the Wellesbourne fly-in in 1980. He called it the Storm Buggy after the Solar Wings Storm wing to which it was mated, and fitted it with a 400 cc Solo engine, direct drive and side-by-side seating.
Nick converted the Storm Buggy to single-seat configuration and used it for various sporting events until 1981, when serious production of single-seaters began, using initially the 340 Sachs engine, toothed belt reduction, and his own newly developed three-bladed nylon propeller. Although still called Storm Buggy, this model was suitable for a wide variety of Rogallos and by 1982 was usually found with a Flexiform Sky Sails Medium Striker wing.
Storm Buggys were later produced with Robin EC44 engines and in addition some two-seaters found their way out of Nick's workshop, using Flexiform's Dual Striker wing.
UAS ceased trike production at the end of 1982 to concentrate on propeller design.
Storm Buggy / Medium Striker
Engine: Sachs 340R, 28 hp at 6000 rpm
Propeller diameter and pitch 47 x 28 inch, 1.19 x 0.71 m (three-blade)
Toothed-belt reduction, ratio 2.1/1
Max static thrust 200 lb, 91 kg
Power per unit area 0.14hp/sq.ft, 1.8 hp/sq.m
Fuel capacity 1.3 US gal, 1.1 Imp gal, 5.0 litre
Length overall 11.0 ft, 3.35m
Wing span 34.5ft, 10.52m
Sweepback 15 deg
Total wing area 200 sq.ft, 18.6 sq.m
Wing aspect ratio 7.5/1
Wheel track 4.6 ft, 1.30 m
Wheelbase 5.1 ft, 1.55 m
Nosewheel diameter overall 13 inch, 33 cm
Main wheels diameter overall 13 inch, 33cm
Empty weight 200 lb, 91kg
Max take-off weight 378 lb, 171kg
Payload 178 lb, 81kg
Max wing loading 1.89 lb/sq.ft, 9.2 kg/sq.m
Max power loading 13.5 lb/hp, 6.1 kg/hp
Max level speed 50mph, 80kph
Economic cruising speed 40mph, 64kph
Max climb rate at sea level 700ft/min, 3.6m/s
Take-off distance 100ft, 30 m
Landing distance 150 ft, 45 m
Range at average cruising speed 50 mile, 80 km