A partnership formed by Airbus, Rolls-Royce and Siemens intends to develop a near-term flight demonstrator in pursuit of hybrid-electric propulsion for commercial aircraft.

The E-Fan X hybrid-electric technology demonstrator is scheduled to fly in 2020 following ground tests, provisionally on a BAe 146, with one of the aircraft’s four gas turbine engines replaced by a 2 MW electric motor. A second gas turbine will also be replaced with an electric motor once the technology has been proven.

In the flying demonstrator, the electric propulsion system will obtain its power from a generator that will be powered by a turbine in the fuselage. Take-off and climbing will be supported by lithium-ion batteries, each of which will have 700 kW of power. The craft will be used to study the challenges of high-power propulsion systems, such as thermal effects, electric thrust management, altitude and dynamic effects on electric systems and electromagnetic compatibility issues.

Airbus will be responsible for overall integration as well as the control architecture of the hybrid-electric propulsion system and batteries, and its integration with flight controls. The turbo-shaft engine, 2 MW generator and power electronics will be supplied by Rolls-Royce, which will work with Airbus on the fan adaptation to the existing nacelle and the Siemens electric motor. Siemens will deliver the 2 W electric motors and their power electronic control unit, as well as the inverter, DC/DC converter and power distribution system.

Schematic of the E-Fan X. Source: Airbus