The Rolls-Royce ACCEL (Accelerating the Electrification of Flight) is an

electric aircraft An electric aircraft is an aircraft powered by electricity. Electric aircraft are seen as a way to reduce the environmental effects of aviation, providing zero emissions and quieter flights. Electricity may be supplied by a variety of methods, ...

demonstrator developed by

Rolls-Royce plc Rolls-Royce Holdings plc is a British multinational aerospace and defence company incorporated in February 2011. The company owns Rolls-Royce, a business established in 1904 which today designs, manufactures and distributes power systems for ...

Development

Rolls-Royce developed the ACCEL as a

racing aircraft Air racing is a type of motorsport that involves airplanes or other types of aircraft that compete over a fixed course, with the winner either returning the shortest time, the one to complete it with the most points, or to come closest to a pre ...

to gain the all-electric

air speed record An air speed record is the highest airspeed attained by an aircraft of a particular class. The rules for all official aviation records are defined by Fédération Aéronautique Internationale (FAI), which also ratifies any claims. Speed records ...

, targeting over . The existing electric aircraft record at that time was , set in 2017 by a Siemens powered Extra 330. Designed at

Gloucestershire Airport Gloucestershire Airport , formerly Staverton Airport, is a small airport located in Churchdown, England. It lies west of Cheltenham, near the city of Gloucester and close to the M5 motorway. Its operator claims it to be Gloucestershire's larg ...

, the project is partly funded by the UK government and involves partners such as electric motor and controller manufacturer

YASA Limited YASA is a British manufacturer of electric motors and motor controllers for use in automotive and industrial applications. The company was founded in 2009 by the CTO Dr Tim Woolmer who is also the holder of a number of related motor technology ...

and aviation start-up Electroflight. The team aimed to reach the 1931

Schneider Trophy The Coupe d'Aviation Maritime Jacques Schneider, also known as the Schneider Trophy, Schneider Prize or (incorrectly) the Schneider Cup is a trophy that was awarded first annually, and later biennially, to the winner of a race for seaplanes and ...

speed, which was won by a R-R-powered

Supermarine S.6B The Supermarine S.6B is a British racing seaplane developed by R.J. Mitchell for the Supermarine company to take part in the Schneider Trophy competition of 1931. The S.6B marked the culmination of Mitchell's quest to "perfect the design of ...

, reaching . On 15 September 2021, Rolls-Royce announced the aircraft, named ''Spirit of Innovation'', had successfully completed its first flight, flying from

MoD Boscombe Down MOD Boscombe Down ' is the home of a military aircraft testing site, on the south-eastern outskirts of the town of Amesbury, Wiltshire, England. The site is managed by QinetiQ, the private defence company created as part of the breakup of the D ...

for fifteen minutes. It subsequently reached a top speed of , and sustained over 3 km, over 15 km, and was able to climb to in 3min 22s. The speeds achieved were accepted as world records for electric aircraft by the

Fédération Aéronautique Internationale The World Air Sports Federation (; FAI) is the world governing body for air sports, and also stewards definitions regarding human spaceflight. It was founded on 14 October 1905, and is headquartered in Lausanne, Switzerland. It maintains worl ...

in January 2022.

Design

The span aircraft is powered by triple stacked 200kW YASA 750R

axial flux motor An axial flux motor (axial gap motor, or pancake motor) is a geometry of electric motor construction where the gap between the rotor and stator, and therefore the direction of magnetic flux between the two, is aligned parallel with the axis of ro ...

s with a high

power density Power density, defined as the amount of power (the time rate of energy transfer) per unit volume, is a critical parameter used across a spectrum of scientific and engineering disciplines. This metric, typically denoted in watts per cubic meter ...

driving a single three-blade propeller spinning at 2,400 RPM. The 750 Volt, 73 kWh battery has 6,480 cells, with cork insulation and active cooling. Battery output power will be continuous, reaching at maximum power. It is designed to have the highest

energy density In physics, energy density is the quotient between the amount of energy stored in a given system or contained in a given region of space and the volume of the system or region considered. Often only the ''useful'' or extractable energy is measure ...

for an aircraft, and should allow a range. The aircraft is derived from the carbon fibre

Sharp Nemesis NXT The Sharp Nemesis NXT with "NXT" standing for "Neoteric experimental Technology," is a kit-built sport-class aircraft designed specifically for air racing. It serves as a successor to the previous model, the Sharp Nemesis, and was created by ...

racer, which has a cruising speed of with a piston engine, but can reach with a highly tuned engine. The maximum take-off weight of the NXT is 1,200 kg. Rolls-Royce intend the battery, motors and control equipment in a production system to weigh the same as the regular engine and fuel tank in a conventional aircraft, but the battery pack alone in the ''Spirit of Innovation'' currently weighs 450 kg. The aircraft's livery was designed by the renowned Italian designer Mirco Pecorari, known for his expertise in aviation aesthetics and branding.

References

External links

* {{Rolls-Royce plc aeroengines ACCEL Electric aircraft Low-wing aircraft Aircraft first flown in 2021 Three-engined single-prop tractor aircraft