Blue sky thinking

The Rolls-Royce EVTOL project
Rolls-Royce has unveiled a concept electric vertical take-off and landing (EVTOL) vehicle at the Farnborough International Airshow 2018.

The design could be adapted for personal transport, public transport, logistics and military applications and is based upon technologies that already exist or are currently under development. It could take to the skies as soon as the early 2020s.

The Rolls-Royce EVTOL project is part of our strategy to ‘champion electrification’ and realise our ambition to become the world’s leading industrial technology company. It builds upon experience gained providing hybrid electric propulsion for trains, naval vessels and other applications, and our expertise in gas turbines, VTOL technology, systems analytics and aerospace regulation and certification. We would expect any commercial introduction of the EVTOL to involve working in collaboration with airframers and will seek a range of strategic partners for aspects of the electrical system.

The initial concept vehicle uses gas turbine technology to generate electricity to power six electric propulsors specially designed to have a low noise profile. It also has a battery for energy storage. In this hybrid-EVTOL configuration it could carry four or five passengers at speeds up to 250mph for approximately 500 miles, would not require re-charging – as the battery is charged by the gas turbine – and would be able to utilise existing infrastructure such as heliports and airports.

We believe that given the work we are doing today to develop hybrid electric propulsion capabilities, this model could be available by the early to mid 2020s, provided that a viable commercial model for its introduction can be created.
The wings are able to rotate 90 degrees, enabling the vehicle to take off or land vertically. The propellers on the wing could fold away once the craft has reached cruising height, reducing drag and cabin noise, with the craft relying upon the two rear propellers for thrust.

The EVTOL – or personal air mobility – market is emerging as a result of technological advances and a need to meet the demands that will be placed upon conventional transport systems as more of the world’s population lives in large cities plagued by congestion. EVTOL will also play a role in meeting the requirement for more efficient travel with fewer emissions.

Rob Watson, who heads up Rolls-Royce’s Electrical team, said: “Electrification is an exciting and inescapable trend across industrial technology markets and while the move to more electric propulsion will be gradual for us, it will ultimately be a revolution. Building on our existing expertise in electric technologies and aviation, Rolls-Royce is actively exploring a range of possible markets and applications for electric and hybrid electric flight. We are well placed to play a leading role in the emerging world of personal air mobility and will also look to work in collaboration with a range of partners.

“Rolls-Royce has a strong track record as pioneers in aviation. From developing the first turbo-prop and jet engines, to creating the world’s most efficient large civil aero-engine and vertical take-off and landing solutions, we have a very strong pedigree. As the third generation of aviation begins to dawn, it’s time to be pioneers yet again.”

The initial Rolls-Royce EVTOL concept uses an M250 gas turbine which is embedded within the rear of the aircraft and modified as part of a hybrid electric propulsion system. The M250 is a highly successful Rolls-Royce engine. Over 31,000 have been delivered since the first version entered service over half a century ago, with an estimated 16,000 currently in service. It has powered more than 170 different helicopter and fixed wing civil and military applications and the whole fleet has clocked up more than 250 million flying hours.

The Rolls-Royce EVTOL concept

Flexible aircraft platform for personal, commercial passenger, cargo and military applications
Tilting wings for vertical take-off and landing (VTOL)
At cruise height the propellers on the wing fold away to reduce drag and cabin noise, the craft then uses the two rear propellers for thrust
Versatile 4/5 seat cabin
Range 500 miles, cruise speed 250 mph
M250-based hybrid propulsion system
The M250 hybrid electric engine will deliver approx. 500kW electrical power
High energy density battery to provide additional climb power
6 propulsion/lift motors with embedded power electronics
Offering customers new capability at vehicle, system and component level”

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