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The CL02, a turbine ULM based on R22


CL for… Claude Lescure! This former captain of Airbus A380, who is not at his first attempt, flies a Robinson powered by a turbine and sufficiently lightened to enter the ULM category. Amazing!



“The CL02 marks the culmination of five years of work explains Claude Lescure. A long and sometimes complex work, but which finally leads to an exceptional result”.

When he embarked on the adventure in 2015, Claude Lescure did not start from scratch: in addition to his extensive experience on aircraft, 20,000 flight hours from the DC-3 to the A380, he had behind him a fine career on a helicopter, with 2800 hours of pilot flight and 800 hours in instruction. “I started in 2005 by building a Safari (NDA: a two-seater of 180hp offering a furious resemblance to the Bell 47) with which I accumulated 300 flight hours. I then rebuilt and owned an Exec 162 (Rotorway) while passing my pilot and examiner ratings on R22 and R44. I now manage my DTO in Compiègne”.

After this stage, Claude Lescure wanted to make the R22, a helicopter he describes as fabulous, a new class 6 ULM. Objective: to combine the qualities of a solid and proven device with the freedom offered by the world of microlight.

“The challenge was to reduce the mass of the R22 by a hundred kilograms and for that the only way to achieve this was to replace the Lycoming with a 40kg turbine. And I started thinking about the question…”

The solution came from a Rolls Royce turbine, actually a fighter jet APU (auxiliary power unit), purchased from a British dealer for a small handful of cash. Forty kilos for the turbine against 140 for the Lycoming, with a fairly equivalent level of power (class 6 limits engine power to 143 hp) : the objective of an empty weight of 300 kg for the R22 is then at hand. All that remains is to make a success of the marriage between the carp and the rabbit. Claude Lescure lists the construction site, which therefore took him several years: "I had to modify the clutch system, mechanical and electrical, add a new additional transmission box to lower the turbine speed to 2700 rpm, switch the electrical circuit to 28V for starting, install an electronic engine control unit, modify the hydromechanical FCU (flight control unit) of the engine speed control, modify the dashboard, etc”.

The development was done on the ground with multiple passages on an original test bench, then with flight tests to validate compliance with the CS27 or HUL standard.

"For all that I had to go back to electronics, but I was also helped by a friend who was an expert in programming microprocessors and very well advised by the technological university of Compiègne" explains Claude Lescure. Still, the DGAC, informed of the project, showed some reluctance at the start  , think, a turbine-powered ULM helicopter… the first in France! But nothing in the regulatory texts could oppose it and the DGAC finally  decided favorably.

         Claude Lescure ne tarit pas d praise today on its creation. “I have always flown on underpowered helicopters and now I discover a new world: the CL02 takes off vertically with two people on board. The turbine consumes 45 and 50 liters per hour, against 32 for the R22 Lycoming. But kerosene or diesel  are much cheaper than 100L, which means that the hourly cost is ultimately lower with my device. The device vibrates less, and it is also quieter: the measurements made give 60 dB at 500 feet against 65 for the Robinson”. Please note, however: the CL02 is not for sale!  But for those who want to embark on an identical project, Claude Lescure can provide modified turbines with all the ECU, FCU and electronic device equipment. developed necessary for the clutch.

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