Unmanned Systems Technology 004 | Delair-Tech DT18 | Autopilots | Rotron RT600 | Unmanned surface vehicles | AMRC | Motion control | Batteries

41 engine and propeller). The following year he established Parajet as a manufacturer of powered paragliders. Clearly, in this world of backpack flight, the propulsion source must be very compact, so a high-performance single- cylinder air- or liquid-cooled two-stroke is commonly used. Cardozo says Mission Everest prompted him to look outside the box. Sponsored by GKN and raising money for charity, this was a May 2007 attempt by himself and TV adventurer Bear Grylls to fly above the summit of Mt Everest. Grylls succeeded, whereas Cardozo fell short by a few hundred metres because of a technical issue with the supercharger. Grylls set an unofficial altitude record for powered paragliding, at 8990 m (29,494 ft). For Mission Everest, in the face of the thin air and extreme cold, Cardozo had eschewed the usual two-stroke in favour of a supercharged four-stroke rotary. In doing so he had teamed up with Brian Crighton, developer of the Norton motorcycle rotary race engine used to win British Championship titles in the late 1980s. Crighton had gone on to develop a Grand Prix motorcycle, but in the mid-1990s the rules were changed, eliminating rotary engines from racing. Mission Everest used a supercharged 300 cc single-rotor engine, which was fuel-injected. Looking back at the Everest adventure, Cardozo says, “We learnt a lot about the capability of the rotary engine through that project. Before that we were using our 180 cc single-cylinder two- strokes, manufactured in-house, for our paragliders. The rotary offers superior power for a given weight and is kinder to the airframe and payload thanks to its lack of vibration.” Since then Crighton has joined GIG and has assisted Cardozo in developing rotary engines for both ultra-light aviation and UAV use. Cardozo says, “The requirements are similar – you run much of the time at sustained high power, and the customer expects the motor to be reliable over a long period of use.” Impressed by Mission Everest, the UK’s Ministry of Defence contracted GIG to develop a rotary engine for a UAV designed to loiter at 30,000 ft. This project wasn’t seen through to production but in 2009 GIG won an order from Raytheon for rotary engines to equip its Killer Bee UAV platform. “We learnt a lot about the UAV industry from this project, and saw good market potential,” Rotron RT600 UAV rotary engine | Dossier We’ve learnt a lot about the rotary engine –it offers superior power for a given weight and is kinder to the airframe thanks to its lack of vibration Unmanned Systems Technology | Autumn 2015 The RT600’s rotor and seals