easyJet and Rolls-Royce have announced the successful completion of an important phase in testing hydrogen as an aviation fuel, marking another step towards the development of technologies that could reduce emissions in air transport in the future.
As part of the testing programme, a modified Rolls-Royce Pearl 15 engine ran on 100 percent hydrogen and reached full take-off power. The test was carried out at NASA’s Stennis Space Center, near Bay St. Louis in the US state of Mississippi.
According to the companies, this was the first industry test of its kind in which a modern aircraft engine, scalable to power narrowbody aircraft, safely operated on gaseous hydrogen through a fully simulated flight cycle. The test covered engine start-up, take-off, cruise and landing, as well as operation under more demanding conditions.
The result is part of a four-year collaboration between easyJet, Rolls-Royce and global partners on the development of hydrogen technologies for aviation. The aim of the programme was to gather engineering insight into the potential use of hydrogen in future propulsion systems, particularly in the segment currently dominated by narrowbody aircraft.
The programme was developed gradually. Initial tests were carried out in 2022 at Boscombe Down in the United Kingdom, where easyJet and Rolls-Royce ran a modern Rolls-Royce AE2100 aircraft engine on 100 percent green hydrogen. A year later, at the German Aerospace Center, DLR, in Cologne, Rolls-Royce tested a full annular combustor from a Pearl engine on 100 percent hydrogen under conditions representing maximum take-off thrust.
The latest phase of the programme at NASA’s Stennis Space Center brought full integration of the hydrogen system into a demonstrator engine. During development, particular attention was paid to hydrogen combustion, fuel systems, engine control, safety and engine behaviour across different operating regimes, including simulated fault scenarios.
easyJet said the test represents an important step towards its ambition to reach net zero emissions by 2050. David Morgan, Chief Operating Officer at easyJet, said the successful test confirmed the progress achieved through the partnership with Rolls-Royce, from early concept to full engine build and testing in just a few years.
Adam Newman, Chief Engineer of Rolls-Royce’s Hydrogen Demonstrator Programme, said the programme had provided the clearest understanding yet of how hydrogen behaves in a modern aero gas turbine. According to Newman, combustion, fuel system and control system technologies were validated, while the knowledge gained will also be applied to future Rolls-Royce programmes, including UltraFan.
Tata Consultancy Services, the UK’s Health and Safety Executive and NASA Stennis also took part in the programme. TCS supported Rolls-Royce through engineering, systems and software capabilities, while HSE developed and tested the infrastructure for the safe handling of pressurised hydrogen. NASA Stennis provided the testing infrastructure and expertise required for this type of propulsion technology testing.
Although hydrogen is still not an immediate operational solution for commercial aviation, this test shows that the technology is moving from the theoretical and laboratory phase towards increasingly serious demonstrations on real aircraft engines. In the future, hydrogen could play an important role in reducing emissions, alongside sustainable aviation fuels, fleet renewal, more efficient operations and airspace modernisation.
