Aerospace engineers at Siemens, Boca Raton, Fla., EADS, Herndon, Va., and Diamond Aircraft, London, Ont., Canada, are field-testing the DA36 E-Star, a plane that is a stepping-stone between gas power and a pure electric vehicle. The E-Star is the first aircraft to use electric power from a generator driven by a small gas engine. The two-seat, prop-driven plane’s serial-electric hybrid drive lets the aircraft take off quietly and cuts fuel consumption and emissions by up to 25%.

The plane carries a relatively small Wankel rotary engine from Austro Engines, Germany. It spins a generator, which, in turn, powers a 70-kW electric motor that turns the prop. The 28.5-lb motor gets additional electricity for taking off and climbing from a battery. The battery recharges during cruising. Overall, the plane uses 80 kW of power on takeoff and 65 kW during cruise. A new Siemens drivetrain cuts the airplane’s weight by 220 lb, which significantly extends its range.

The technology in the plane is scalable, according to Siemens, and it will soon be used in small aircraft and then commercial planes carrying 50 to 100 passengers.



Diamond Aircraft