First Flight: Electric, Untethered, Piloted Helicopter
Pascal Chretien of France flew his own electric-powered helicopter design untethered for two minutes and 10 seconds last month, beating out Sikorsky's Firefly for the first flight of its kind. Chretien, an aerospace engineer and helicopter pilot, spent about a year working on the project, mostly on his own, according to Gizmag. He devised several innovative solutions to simplify the design and minimize the weight and power needs. He used two counter-rotating rotors to eliminate the tail rotor, weight-shift control for steering, and a simple frame welded from aluminum tubing. The system is tricky to fly, according to Chretien: "This machine looks like a toy, and flies like a toy, but there is a raging tiger under the seat, waiting to bite at the first mistake," he told Gizmag. "In case of crash I stand good chances to end up in kebab form."
Chretien hovered the helicopter on Aug. 12 in France, reaching a maximum height of 1 meter off the ground. It's powered by lithium batteries and brushless DC motors, according to EAA. Chretien's work was supported by Solution F, a French company that develops specialized hybrid engines for a variety of vehicles. Chretien told Gizmag he plans to continue refining the design and hopes to expand the flight envelope. He believes that a hybrid helicopter power system could prevent up to 40 percent of helicopter crashes, by providing reserve battery power in the event of an engine failure. AVweb's Glenn Pew took a tour of Sikorsky's Firefly at EAA AirVenture in 2010; click here for his video report.