Britain's Rolls-Royce (RR.L) said it has successfully run an aircraft engine on hydrogen, a world aviation first that marks a major step towards proving the gas could be key to decarbonising air travel.
The ground test, using a converted Rolls-Royce AE 2100-A regional aircraft engine, used green hydrogen created by wind and tidal power.
Rolls and its testing programme partner easyJet are seeking to prove that hydrogen can safely and efficiently deliver power for civil aero engines.
They said they were already planning a second set of tests, with a longer-term ambition to carry out flight tests.
Hydrogen is one of a number of competing technologies that could help the aviation industry achieve its goal of becoming net zero by 2050.
A switch to hydrogen-powered engines would require a complete redesign of airframes and infrastructure at airports.