World's first hybrid plane takes off
Researchers from the University of Cambridge have successfully tested the world's first aircraft powered by both an electric motor and a petrol engine.
The single-propeller test plane uses up to 30% less fuel than a comparable aircraft and is also able to recharge its batteries in flight - another world first.
Project leader Dr Paul Robertson said "Although hybrid cars have been available for more than a decade, what's been holding back the development of hybrid or fully-electric aircraft until now is battery technology."
"Until recently, they have been too heavy and didn't have enough energy capacity. But with the advent of improved lithium-polymer batteries, similar to what you'd find in a laptop computer, hybrid aircraft - albeit at a small scale - are now starting to become viable."
Built by engineers at Cambridge with funding from Boeing, the electric motor helps power the propeller on take-off and can then be switched to 'generator mode' to recharge the batteries when cruising speed is attained.
The researchers admitted that the technology was still a long way from helping the aviation industry reach its 2050 target of a 50% net reduction in CO2 emissions compared to 2005 levels.
Currently, if all the engines and all the fuel in a modern jetliner were to be replaced by batteries, it would have a total flying time of roughly ten minutes.
"Our mission is to keep our sights on finding innovative solutions and technologies that solve our industry's toughest challenges and continually improve environmental performance," said Boeing's principal investigator for the programme Marty Bradley.
"Hybrid electric is one of several important elements of our research efforts, and we are learning more every day about the feasibility of these technologies and how they could be used in the future."