Concept
A hybrid electric aircraft is an aircraft with a hybrid electric powertrain. As the energy density of lithium-ion batteries is much lower than aviation fuel, a hybrid electric powertrain may effectively increase flight range compared to pure electric aircraft. By May 2018, there were over 30 hybrid electric aircraft projects, and short-haul hybrid-electric airliners were envisioned from 2032. The Boeing Truss-Braced Wing subsonic concept was planned with hybrid electric propulsion. The Diamond DA36 E-Star first flew on 8 June 2011, the first flight of a series hybrid powertrain, reducing fuel consumption and emissions by up to 25%, a technology scalable to a 100-seater airliner. A small and lighter Austro Engine 40 hp (30 kW) Wankel engine generates the electricity, supplemented by EADS batteries for silent take off, feeding a Siemens 70 kW (94 hp) electric motor turning the propeller. The AgustaWestland Project Zero was intended to be hybrid-electric. Nasa sponsored a centennial challenge to encourage the development of the world's most fuel-efficient airplane. The contest got co-sponsored by Google and was conducted in California skies. Amongst the entrants was the world's first parallel gas-electric hybrid aircraft called the EcoEagle, built by students of Embry-Riddle Aeronautical University, two electric airplanes - the Pipistrel Taurus G4 and the eGenius. Faradair Aerospace launches a Triple Box-wing hybrid electric aircraft concept Called the BEHA (Bio Electric Hybrid Aircraft) as one of the world's first regional aircraft specifically designed for hybrid electric regional flight. The UK start-up has continued development from the initial concept to the latest BEHA M1H variant, with future opportunity for unmanned and all electric variants. The E-STOL BEHA has gained support from key members of the UK Government and the airframe development has been conducted at Swansea University. Zunum Aero, backed by Boeing and JetBlue, is working since 2014 on a family of 10- to 50-seat hybrid electric regional aircraft.