- The first manned, hydrogen-powered plane has been successfully tested in the skies above Spain, its makers say.
The small, propeller-driven craft, developed by aviation giant Boeing, made three short flights at an airfield south of Madrid, the company said.
It was powered by hydrogen fuel cells, which produce only heat and water as exhaust products.
The tests could pave the way for a new generation of greener aircraft, the company said.
Boeing's chief technology officer John Tracy said the flights were "a historical technological success" and "full of promises for a greener future".
Three test flights of the two-seater aircraft took place in February and March at an airfield at Ocana, south of Madrid. The plane was modified to include a hybrid battery and fuel cell system developed by UK firm Intelligent Energy.
The fuel cells, which create electricity by combining oxygen and hydrogen, were used to power an electric motor coupled to a propeller.
During take-off the plane's batteries were used to provide an additional boost, but whilst in the air, the plane relied entirely on the cells.
Boeing said the plane has a flying time of 45 minutes but tests were limited to around half that time.