Air-Britain Archive 1-1995

The information given on the Tribian was: Gross Weight 4214 lb, Disposable load 1321 lb, Span 44 ft 6 in, Length 34 ft, Height 13 ft 2 in. Power was to be provided by two 145hp Gipsy Major 10 or 155hp Cirrus Major III; max speed 153 mph, cruising speed 140 mph at sea level, stalling speed 55 mph, service ceiling 14,500 ft, initial rate of climb 900 ft/min, range (full load) 550 miles. It would seat a pilot and three passengers.
  The original models clearly only represented ideas as, when design work produced the mockup, proportions and detail changed considerably. These changes (see photos) included a much higher-mounted sponson and lowered engine nacelles. The false registration shown on one model was G-DRSW, the initials of Douglas Reoch and Simon Warrender who formed Sponson Developments. The lack of further publicity suggests that no orders were confirmed to justify starting construction.