Rolls-Royce and easyJet have set a new aviation milestone with the world’s first run of a modern aero engine on hydrogen. The ground test was conducted on an early concept demonstrator using green hydrogen created by wind and tidal power. It marks a major step towards proving that hydrogen could be a zero carbon aviation fuel of the future and is a key proof point in the decarbonisation strategies of both Rolls-Royce and easyJet. Both companies have set out to prove that hydrogen can safely and efficiently deliver power for civil aero engines and are already planning a second set of tests, with a longer-term ambition to carry out flight tests. The test took place at an outdoor test facility at MoD Boscombe Down, UK, using a converted Rolls-Royce AE 2100-A regional aircraft engine. Green hydrogen for the tests was supplied by EMEC (European Marine Energy Centre), generated using renewable energy at their hydrogen production and tidal test facility on Eday in the Orkney Islands, UK. Following analysis of this early concept ground test, the partnership plans a series of further rig tests leading up to a full-scale ground test of a Rolls-Royce Pearl 15 jet engine. The partnership is inspired by the global, UN-backed Race to Zero campaign that both companies have signed up to, committing to achieve net zero carbon emissions by 2050.