22 Jul 2024


Rolls-Royce plans electric planes that will take off vertically

Rolls-Royce has unveiled plans for an electric plane that would take off and land vertically, at the at the Farnborough International Airshow in the UK. The hybrid Evtol (electric vertical take-off and landing) aircraft will have tilting wings and will be able to carry four or five passengers at speeds of up to 250mph (400km/h) for about 500 miles (800km). Rolls-Royce says it could take to the skies in the early 2020s.

Another Rolls-Royce-led project called Accel (ACCELerating the Electrification of Flight) aims to build and test a small electrically powered aircraft within 24 months. The project will tackle the twin challenges of energy storage and powertrain performance with the goal of setting a new record for time-to-climb for an electrically-powered aircraft, as well as achieving the highest voltage and power densities for aircraft battery systems. One of Rolls’ partners in the project is the UK developer of high-power, lightweight, axial-flux electric motors and controls, Yasa. Another is Electroflight UK, which specialises in high-performance electric powertrains with integrated energy storage systems.

Also at Farnborough, the UK government announced that it was contributing towards the cost of a demonstration hybrid-electric propulsion system for commercial aircraft that is being developed jointly by Rolls-Royce, Airbus and Siemens in a £58m project, called E-Fan X. The funding was part of £343m government-industry investment programme in aerospace r&d and productivity improvements announced at the show, much of this devoted to electric and hybrid aircraft technologies.

Rolls-Royce’s Evtol design uses tilting wings that will be able to rotate through 90 degrees to allow vertical take-off and landing. The initial concept vehicle uses gas turbines to generate electricity to power six low-noise electric “propulsors” – four on the wings, and two on the tailplane. The propulsion and lift motors will have embedded power electronics. The craft will incorporate a high energy-density battery for energy storage and to provide additional climbing power.

The hybrid Evtol configuration would not need re-charging (because the battery would be charged by the gas turbine), and would be able to use existing infrastructure such as heliports and airports.

When the craft reaches cruising height, the wing-mounted propellers could fold away, reducing drag and cabin noise, with the craft relying on the two rear propellers for thrust.

The initial Rolls-Royce Evtol concept is based on an M250 gas turbine embedded in the rear of the aircraft as part of a hybrid electric propulsion system. The hybrid electric engine will deliver about 500kW of electrical power

Rolls-Royce believes that this concept could be adapted for personal transport, public transport, logistics and military applications. It says that the design is based on technologies that already exist or are under development, and that the aircraft could take to the skies as soon as the early 2020s.

Before the Evtol technology can become commercial, Roll-Royce will probably collaborate with partners with expertise in areas such as the electrical systems and airframe.

The projects announced at Farnborough are part of Roll-Royce’s strategy to “champion” electrification and to become a leading industrial technology company. They build on the experience that the company has gained from supplying hybrid electric propulsion systems for trains, naval vessels and other applications, as well as its expertise in gas turbines, VTOL technology, systems analytics and aerospace regulation and certification.

“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,” predicts Rob Watson, who heads Rolls-Royce’s electrical team. “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,” he adds. “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 UK government’s £343m r&d programme with the aerospace industry is aimed at transforming the future of civil aerospace and maintaining the UK’s status as a leading aerospace nation. £255m will go towards 18 new research and technology projects, including the development of hybrid aircraft. £68m of funding will be made available to increase r&d in small and medium-sized companies, and £20m will be used to improve productivity in the sector.

A major beneficiary of the funding will be the Airbus/Siemens/Rolls-Royce E-Fan-X project that aims to develop a flying demonstrator that will form the basis for future electric aircraft, and help the aerospace sector to produce cleaner, quieter aircraft.

The UK government has also started negotiations with the aerospace sector for an Industrial Strategy deal that will increase investment further and explore opportunities for electrification, supply-chain productivity and increased skill levels. The discussions are expected to conclude before the end of 2018.