The Spirit of Innovation aeroplane hit a top speed of 623km/h (387.4mph) during flights on Tuesday (16 November), the UK company said. It has submitted data to the Fédération Aéronautique Internationale (FAI), which controls and certifies world aeronautical and astronautical records.
Flying over the Ministry of Defence’s Boscombe Down experimental aircraft testing site in Wiltshire, the aircraft reportedly hit 555.9km/h over three kilometres. The plane also achieved 532.1km/h over 15 kilometres – 292.8km/h faster than the previous record – and broke the fastest time to climb to 3,000m by 60 seconds, with a time of three minutes and 22 seconds, according to Rolls-Royce data.
The aircraft was propelled by a 400kW (500+hp) electric powertrain, and what Rolls-Royce called “the most power-dense propulsion battery pack ever assembled in aerospace”. The company worked with aviation energy storage specialist Electroflight and automotive powertrain supplier Yasa.
The speed achieved by the test pilot, Rolls-Royce director of flight operations Phill O’Dell, was more than 213.04 km/h faster than the previous record set by the Siemens eAircraft-powered Extra 330 LE Aerobatic aircraft in 2017.
“Never in the history of the FAI record attempts has there been such a significant increase in speed over such a short time, highlighting the rapid pace at which electrification of aerospace is advancing,” a Rolls-Royce announcement said.
The company said that the project and world record runs provided important data for its future power and propulsion systems for all-electric urban air mobility and hybrid-electric commuter aircraft. Flying taxis could require similar battery characteristics, for example.
“Electric flight is set to be as transformative for mobility as the jet engine was 70 years ago,” said Dr Tim Woolmer, Yasa’s founder and chief technology officer. “It’s thrilling to see our ultra-high performance, super-low weight electric motors powering the Spirit of Innovation to these great speeds, and to know that collaborative projects like Accel (Accelerating the Electrification of Flight) take us one step closer to emissions-free electric flight becoming a commercial reality for all.”
Despite the high speeds of this week’s test flights, commercially-successful electric flight is far from assured. The size and range of electric aircraft are limited by their batteries, which are far less energy dense than fossil fuels such as kerosene. Without major battery breakthroughs, commercial electric flight is likely to be limited to small aircraft flying shorter regional routes.
Half of the Accel project’s funding is provided by the Aerospace Technology Institute, in partnership with the Department for Business, Energy & Industrial Strategy and Innovate UK.
“The advanced battery and propulsion technology developed for this programme has exciting applications for the advanced air mobility market,” said Rolls-Royce CEO Warren East. “Following the world’s focus on the need for action at Cop26, this is another milestone that will help make ‘jet zero’ a reality, and supports our ambitions to deliver the technology breakthroughs society needs to decarbonise transport across air, land and sea.”
Business secretary Kwasi Kwarteng said: “This record will show the potential of electric flight and help to unlock the technologies that could make it part of everyday life. The government is proud to back projects like this to leverage the private investment necessary to unlock cleaner, greener aircraft, which will allow people to fly as they do now, but in a way that cuts emissions.”
Want the best engineering stories delivered straight to your inbox? The Professional Engineering newsletter gives you vital updates on the most cutting-edge engineering and exciting new job opportunities. To sign up, click here.
Content published by Professional Engineering does not necessarily represent the views of the Institution of Mechanical Engineers.