Building the world’s fastest all-electric aircraft

Technology testing complete

Our ambitions to build the world’s fastest all-electric aircraft have taken an important step forward with the completion of the testing of the ground-breaking technology that will power the world’s fastest all-electric plane. All the technology has been tested on a full-scale replica of the plane’s core, called an ‘ionBird’, including a 500hp electric powertrain powerful enough to set world speed records and a battery with enough energy to supply 250 homes.

The plane is part of our initiative called ACCEL, short for ‘Accelerating the Electrification of Flight’ which was launched at Farnborough Air Show in 2018. Our ACCEL project team includes key partners YASA, the electric motor and controller manufacturer, and aviation start-up Electroflight. The team has been developing the technology at Gloucestershire Airport while adhering to the UK Government’s social distancing and other health guidelines and the systems will soon be integrated into our ‘Spirit of Innovation’ plane.

The ionBird

There is a long history of iron-birds in aviation for testing propulsion systems ahead of flight, but in this case we have named the test airframe ‘ionBird’, after the zero-emission energy source propelling the aircraft.

Supporting our net zero carbon ambitions

“Rolls-Royce is committed to playing a leading role in reaching net zero carbon by 2050. The completion of ground-testing for the ACCEL project is a great achievement for the team and is another important step towards a world record attempt. This project is also helping to develop Rolls-Royce’s capabilities and ensure that we remain a leader in delivering the electrification of flight, an important part of our sustainability strategy.”

Dr. Rob Watson. Director of Electrical, Rolls-Royce.

Commitment to testing every component

Our dedicated team have tested each and every component of the system including:
  • Running the propeller up to full speed (approximately 2,400 rpm) using the most power-dense battery pack ever assembled for aircraft propulsion. When at full power during the flight-testing phase, it will propel the aircraft to more than 300mph setting a new world speed record for electric flight. Over 6,000 cells are packaged in the battery for maximum safety, minimum weight and full thermal protection.
  • Since January, our engineering and test pilots have spent many hours optimising the system and developing operating procedures for electric flight.
  • Generating GBs of data every hour of operation which the team have analysed to improve performance wherever possible.

Matheu Parr, Rolls-Royce ACCEL Project Manager said: “Finishing the ground-testing of a propulsion system that is going to power the world’s fastest electric plane is an incredible achievement for our team. There have been many challenges to overcome in this time, including fully integrating our lightweight propulsion system with a bespoke power-dense battery. We are now looking forward to building the system into the plane before entering the exciting flight-testing phase.”

The propeller is driven by three high power density axial electric motors and compared to a conventional plane, the propeller blades spin at a far lower RPM to deliver a more stable and far quieter ride. Combined they’ll continuously deliver more than 500 horsepower for the record run. Even during the record run the all-electric powertrain delivers power with 90% energy efficiency and of course zero emissions. (In comparison, a Formula 1 race car tops out at close to 50% energy efficiency).

Timing partner for the world-record run

Bremont, will be the official timing partner for the all-electric speed record attempt.

The British luxury watch maker has helped develop the design of the plane’s cockpit which will feature a stopwatch, while the company has machined canopy release parts at its Henley-on-Thames manufacturing facility.

The first flight is planned for later this year and we are aiming to beat the current all-electric flight world record. Half of the project’s funding is provided by the Aerospace Technology Institute (ATI), in partnership with the Department for Business, Energy & Industrial Strategy and Innovate UK.

Mark Scully, Head of Technology for Advanced Systems & Propulsion at the Aerospace Technology Institute, said: “The significance of reaching this milestone should not be underestimated. The ACCEL team is pioneering the integration of high-performance batteries, motors and drives to deliver an electric propulsion system in an ambitious flight test programme. These technologies and the systems integration needed to utilise them hold great potential for future sustainable aviation, which is why the ATI is proud to support the project.”

The ACCEL project is a series of firsts for Rolls-Royce as we journey towards net zero carbon by 2050.

It is the first Rolls-Royce project to use offsetting to make the whole programme carbon neutral.

We are also looking to inspire young people, with the ACCEL project, to consider STEM careers (Science, Technology, Engineering and Maths). We have developed downloadable materials aimed at primary school children around the project. These are linked to the UK curriculum and everything can be downloaded from the Spirit of Innovation STEM section of our website.

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