Europe’s Clean Sky research program has given birth to a Green Rotorcraft initiative which may yield diesel-powered helicopters from Agusta Westland and Eurocopter. The latter’s CEO, Lutz Bertling, revealed on Feb. 23 that the company is working on bringing diesel power to a light helicopter, following a story in the Feb. 16 edition of Aviation Week speculating on the Green Rotorcraft project.
Bertling said that a diesel Eurocopter – most likely an EC120 – would fly within 30 months. Although he did not mention the many challenges to making that happen, the Aviation Week article said that EADS (of which Eurocopter is a division) hopes to show a diesel-powered helicopter at the Paris Air Show in June. EADS Chief Technical Officer Jean Botti said, however, that an actual flight “is still about two years off.”
Botti told Aviation Week that the engine for the demonstrator already has been chosen, but said little more beyond that it will weigh around 550 pounds and deliver 300 kw of power while burning about 220 grams – 0.07 gal. – per kilowatt hour. The goal is to cut fuel consumption by 40% below that of a comparable turbine-powered helicopter, said Olivier Jouis, Eurocopter’s director of environmental matters.
Jouis acknowledged that there are plenty of technical challenges to be overcome. Getting the tolerances right for airborne applications is “not trivial,” he pointed out, nor is design of the reduction gear, which will have to endure the stresses associated with the torque and vibration of a piston diesel engine. Jouis said that the engine will have “more than eight cylinders” to minimize the vibration and torque stresses.