Three major European companies are teaming up to develop a hybrid passenger plane that uses an electric turbofan along with three conventional jet engines.
The plane is an effort to develop and demonstrate technology that could help limit emissions of carbon dioxide from aviation and reduce reliance on fossil fuels.

Airbus, Siemens and Rolls-Royce said they aim to build a flying version of the E-Fan X technology demonstrator plane by 2020.

The aircraft would be based on a BAe 146 four-engine jet. The hybrid version would generate electric power through a turbine within the plane, which would be used to turn the fan blades of the electric turbofan engine.

If the system works a second electric motor could be added, the companies said.

The companies said plane-maker Airbus will build the aircraft's systems into a working whole, control systems and flight controls.

Jet engine-maker Rolls-Royce will make the generator and the turbo-shaft engine, and engineering company Siemens will deliver the two-megawatt electric motor to power the engine.

The companies said they are looking ahead to the European Union's long-term goals of reducing carbon dioxode emissions from aviation by 60%, as well as meeting noise and pollution limits they said "cannot be achieved with technologies existing today".

Other projects for hybrid or electric planes are in the works. US firm Zunum Aero, based in Washington state, says it is working on a 12-seat hybrid-electric commuter jet. The company's website lists its partners as Boeing, jetBlue Technology Ventures and the Department of Commerce Clean Energy Fund.