LONDON—Rolls-Royce claims it has broken the world speed record for an electric-powered aircraft­—555.9 kph (345.4 mph)—with its £6 million ($8.1 million) Spirit of Innovation. 

The aero-engine manufacturer said it has submitted data from a Nov. 16 flight at Boscombe Down, England, to the Federation Aeronautique Internationale (FAI) for ratification.  

If successful, the company will have smashed the existing speed record of by 213.04 kph held by a Siemens’ eAircraft Div. modified Extra 330LE in March 2017. Rolls said the 555.9-kph record was broken in speed runs over 3 km (1.9 mi.).  

But the OEM also is claiming a record of 532.1 kph over 15 km, 292.8 kph faster than the previous record, and a quickest time-to-climb to 3,000 m (9,840 ft.) of 202 sec., 60 sec. faster than the previous holder. 

The company believes it also can claim the mark for the fastest all-electric vehicle with a recorded speed of 623 kph. 

“Flying the Spirit of Innovation at these incredible speeds and believing we have broken the world-record for all-electric flight is a momentous occasion,” said Rolls’ chief test pilot, Phill O’Dell. “This is the highlight of my career and is an incredible achievement for the whole team. The opportunity to be at the forefront of another pioneering chapter of Rolls-Royce’s story as we look to deliver the future of aviation is what dreams are made of.” 

O’Dell flew aircraft for the 3-km speed runs, while Electroflight pilot Steve Jones flew the Spirit of Innovation for the 15 km and the time-to-climb-to-3,000-m record runs that have been submitted. 

Rolls said there has never been such a significant increase in speed in the FAI records over such a short time and the increases in speed highlight the “rapid pace at which electrification of aerospace is advancing.” 

“Staking the claim for the all-electric world-speed record is a fantastic achievement for the ACCEL team and Rolls-Royce,” said CEO Warren East, adding that the technologies developed for the project would have applications for the advanced-air-mobility market and help to decarbonize aviation. Rolls had been flying the modified Sharp Nemesis NXT racing aircraft at Boscombe Down since September in preparation for the record attempts.  

The aircraft was modified in conjunction with Gloucestershire-based electric-aircraft company Electroflight and electric-motor developer YASA. 

At the heart of the modifications is a 450-kg (990-lb.), 6,000-cell lithium-ion DC battery, which was designed for speed rather than endurance and developed from the batteries that drive power tools, enabling the cells to be discharged rapidly. Key to the battery has been the repackaging of the cells to try to deliver around 155 wH per kg, while the battery case has been designed to contain a potential thermal-runaway situation.  

The battery runs three YASA-developed galvanically isolated 750-volt 133-kW motors that give the aircraft a power output of 400 kW, the equivalent of nearly 550 hp. 

Some £6 million has been spent on the project, half each provided by Rolls and t the UK’s Aerospace Technology Institute in partnership with the  country’s Department for Business, Energy and Industrial Strategy.