Three major European manufacturing groups plan to take a significant step toward hybrid-electric propulsion for commercial aircraft, they announced Nov. 28.

Airbus, Rolls-Royce and Siemens have partnered to create a new 2MW electric motor that they hope to fly by 2020.

The new partnership, announced at London’s Royal Aeronautical Society, will develop the E-Fan X program, to investigate some of the challenges of the new technology, including thermal effects and electric thrust management. The new motor will be the world’s most powerful flying generator.

The three organizations are seeking to increase the pace of hybrid-electric development by maturing the technologies, safety and reliability involved.

The new powerplant follows a series of smaller demonstrators in recent years and the partners hope to fly it on a BAe 146 testbed, replacing one of the aircraft’s Avco Lycoming ALF 502 turbofans. A second engine may be replaced with another of the new electric motors once tests have provided sufficient confidence to do so.

Siemens believes that four to eight such motors on the wings of a regional aircraft could power its propellers or fans. In the flying demonstrator, the electric propulsion system will obtain its power from a generator powered by a turbine in the fuselage. Takeoff and climb will be supported by lithium-ion batteries, each of which will have 700kW of power.   

Under the program, Airbus will be responsible for the control architecture of the hybrid-electric motor and its integration with the flight controls, together with overall integration. Rolls-Royce will be responsible for the turboshaft engine, 2MW generator and power electronics, while Siemens will deliver the 2MW electric motor, inverter and other components.

Rolls-Royce’s chief technology officer, Paul Stein, described the new class of motors as being an integral part of the “third generation of aviation.”

Head of Siemens eAircraft, Frank Anton, added: “This large flying demonstrator will be a major step for eAircraft toward a hybrid-electric future. 

“Thanks to our existing drive systems for drones and ultralight and light sport aircraft, we are already involved in aviation.  Recently, we also presented a prototype motor for the CityAirbus, a flying taxi for use in urban areas.

“We are now building on the experience we’ve gained during development of motors with these outputs in order to develop the first solution for a commercial aircraft: a hybrid-electric airliner that can seat 50 to 100 passengers.”

A major impetus behind the new motor comes from long-term international emissions targets, which cannot be reached using current fossil fuel-powered technologies.

Alan Dron