Industry giants are to collaborate on the development of hybrid-electric propulsion for commercial aircraft, an advance that could help cut emissions, aircraft noise and save fuel.

The partnership between Airbus, Rolls-Royce, and Siemens aims at developing a near-term flight demonstrator with the future potential to move regional travel from rail to air at cruising speeds that match current aircraft. The three companies announced the collaboration today, 28 November 2017, at the Royal Aeronautical Society in London.
The E-Fan X hybrid-electric technology demonstrator is anticipated 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 2MW electric motor. Provisions will be made to replace a second gas turbine with an electric motor once system maturity has been proven.
“The E-Fan X is an important next step in our goal of making electric flight a reality in the foreseeable future. The lessons we learned from a long history of electric flight demonstrators, starting with the Cri-Cri, including the e-Genius, E-Star, and culminating most recently with the E-Fan 1.2, as well as the fruits of the E-Aircraft Systems House collaboration with Siemens, will pave the way to a hybrid single-aisle commercial aircraft that is safe, efficient, and cost-effective,” said Paul Eremenko, chief technology officer at Airbus. “We see hybrid-electric propulsion as a compelling technology for the future of aviation.”
The E-Fan X demonstrator will explore 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.
As part of the E-Fan X programme, 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.
Rolls-Royce will be responsible for the turbo-shaft engine, 2MW generator, and power electronics. Along with Airbus, Rolls-Royce will also work on the fan adaptation to the existing nacelle and the Siemens electric motor.
Siemens will deliver the 2MW electric motors and their power electronic control unit, plus the inverter, DC/DC converter, and power distribution system.

Paul Stein, Rolls-Royce CTO, said: “The E-Fan X enables us to build on our wealth of electrical expertise to revolutionise flight and welcome in the third generation of aviation. This is an exciting time for us as this technological advancement will result in Rolls-Royce creating the world’s most powerful flying generator.
Among the top challenges for today’s aviation sector is to move towards a means of transport with improved environmental performance, that is more efficient and less reliant on fossil fuels.
The partners say they are committed to meeting the EU technical environmental goals of the European Commission’s Flightpath 2050 Vision for Aviation (reduction of CO2 by 60%, NOx by 90%, and noise reduction by 75%, all based on 2000 levels) but the targets will be difficult to achieve with current technologies.
Electric and hybrid-electric propulsion systems are considered promising for addressing these challenges and Mark Cousin, head of demonstrators at Airbus believes double digit fuel economy savings could be made with the new configuration.
Still convinced that they should be working on how to use electric power to get existing planes clear of an airport. Take off is when a jet is producing its most pollution, noise and is at its most inefficient .
If they can integrate these new electric hybrid engines into all future commercial airbus planes then they will achieve that result ( a little down the line). Once the new engines and control systems are ready and tested they can be scaled up for the bigger Airbus planes. You can not go from nothing to fully high powered electric engines, control systems, gas generators or extreme battery packs in one go. Takeoff is especially difficult. Just like the car or any other industry is taking many, many years to make the shift to renewable. Unfortunately it takes time. But step by step Airbus, Siemens, Rolls Royce, etc will achieve this for planes. And the airports will be much quieter as a result. Kudo’s to them for pushing this. Hopefully many buyers will show interest and help it go faster and further.
Looks really exciting for small planes. The gas turbine engine size used is capable of about 3.6 MW output for take off, so the 2 MW sizing will be good for cruising. Could be similar to hybrid cars where GTs are used for take-off and longer range use.
I would like a mini version with full autopilot for xmas, maybe next year?
Still waiting for the introduction of electric-powered taxiing systems – eg the powered nosewheels reported in The Engineer 12 years ago. That innovation ought to be capable of introduction well before 2020, with retrofitting a distinct possibility?
As regards the E-Fan X, I’m bothered by an engineering company releasing a schematic and associated text referring to an “energy store” and “li-ion batteries” with their capacities stated in MW and kW respectively.
The electric nosewheel taxiing system is under test at a variety of locations, but certification of new technologies is always a slow process in civil aerospace.
Good point, the energy store is said to be 2 MW, and that is not storage: probably marketing people? The engine provides 2 MW power, which looks right to me, but we do need to know what the storage and battery weight is, especially given the weight of battery packs used in Tesla cars etc., they must be much heavier per MWh than oil storage plus the associated turbines.
I am a bit wary. AIRBUS is exceptionally sharp but has anyone ever seen a 2MW generator? They are massive. Ditto a battery of any use to a motor that size. That being said, AIRBUS will be fully aware of that so it should be interesting.
In Latvia, we conduct research, development and testing of fuel-free generators using centrifugal force. The small size of the device (its weight does not exceed 30 kg) develops a power of 700 kW mechanical power. And this generator turns the turbine without conversion to electric current.
This method allows you to do without batteries, electric generators and electric motors.
We also study the wing on a system such as Vetalaf (vertical takeoff and landing air flow)
Our system allows you to obtain a vertical force of 60 kg at a krill size of 0.25 m at 0.64 m vertically upwards without take-off on the take-off track