The DA36 E-Star, an aircraft designed by Siemens, Diamond Aircraft and EADS, employs a series hybrid powertrain with the propeller being turned by a Siemens electric motor. The aim is to reduce fuel consumption and emissions by up to 25%. An onboard Austro Engines Wankel rotary engine and generator provides the electricity. A propeller speed reduction unit is eliminated. The electric motor uses electricity stored in batteries, with the generator engine off, to take off and climb reducing sound emissions. The series-hybrid powertrain using the Wankel engine reduces the weight of the plane by 100 kg compared with its predecessor. The DA36 E-Star first flew in June 2013, making this the first ever flight of a series-hybrid powertrain. Diamond Aircraft state that the technology using Wankel engines is scalable to a 100-seat aircraft.