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”.