Following its maiden flight in December 2007, the developers of the Electra electrically powered ultra-light aircraft are to continue flight testing to obtain an airworthiness certificate so it can be demonstrated at a general aviation show in Vichy, France in July.
Using 47kg (103lb) of lithium polymer batteries and a 25hp (18kW) electric brush motor, the single-seat Electra was flown for 48min by its test pilot, ACV Aero Service manager Christian Vandamme, around a 50km (27nm) closed circuit on 23 December.
With a 265kg maximum take-off weight, the BL1E Electra is a modified Souricette MB02 homebuilt with a 9m (29.5ft) wingspan, wood and canvas construction and 49kt (90km/h) cruise speed. A new company, Electravia, plans to produce an all-electric aircraft based on this prototype. Electravia founder and Electra project manager Anne Lavrand is looking for funds for its development, says Vandamme.
French aerospace research agency Onera has been helping with development of the Electra by designing its so-called silent propeller. During the 23 December flight observers on the ground could only hear the Electra's aerodynamic-generated noise when it was at 500ft (150m) altitude.
"In the future Electravia will develop a new aircraft completely dedicated to the electrical engine and using a "silent" propeller based on the Onera design," says Vandamme, who adds that ACV is waiting for another permit to continue Electra flight testing.
While there have been many electrically powered unmanned air vehicles, France is claiming the Electra flight as a first for a manned aircraft. US kitplane maker Sonex Aircraft and motor supplier AeroConversions announced in July 2007 that they plan to fly a two-seat Waiex powered by a brushless electric motor and lithium polymer batteries.
Boeing's European research centre in Madrid, Spain, meanwhile, is preparing to fly a Diamond Dimona motor glider re-engined with a hybrid fuel-cell/battery propulsion system. The proton exchange membrane fuel cell will provide all power in cruise flight, while power for take-off and climb will be drawn from lithium-ion batteries.
Flight tests in Spain are intended to demonstrate, for the first time, that a manned aircraft can maintain straight and level flight with fuel cells as the sole source of power, and could pave the way for use of the technology in light aircraft, Boeing believes.
Source: Flight International
