easyJet and Rolls-Royce have completed a major milestone in sustainable aviation: they ran a modern commercial jet engine on pure hydrogen from start-up through takeoff power and back down again. The test, which took place in late April 2026, is a significant step toward cleaner air travel.
The test used a Rolls-Royce Pearl 15 engine — a turbofan engine, which is a type of jet engine that pushes air through a large front fan to produce thrust — normally used in business jets. The team ran the engine on 100% gaseous hydrogen across a full simulated flight cycle, meaning it went through start-up, taxi power, takeoff power, cruise power, and landing power. Crucially, the engine reached full takeoff thrust, which is the most demanding phase of flight.
The test took place at NASA’s Stennis Space Center in Bay St. Louis, Mississippi. Engineers also deliberately tested fault scenarios — situations where something goes wrong — to confirm that safety systems worked correctly under hydrogen conditions.
This was not the first hydrogen engine test by Rolls-Royce and easyJet. In 2022, the partners ran a smaller Rolls-Royce AE2100 engine on 100% green hydrogen at a test facility in the UK. In 2023, Rolls-Royce tested a combustor component from a Pearl engine on hydrogen in Germany. The April 2026 test is the most complete and demanding test to date.
Hydrogen produces only water vapour when it burns, not carbon dioxide. This makes it one of the most promising long-term alternatives to conventional jet fuel, which is a major source of CO2 emissions. The aviation industry is under strong pressure to reduce its environmental impact.
The Pearl 15 is a modern, in-service engine, not a specially designed research engine. This means the results are directly relevant to commercial aviation, not just laboratory science. The test showed that existing engine designs can be adapted to run on hydrogen with manageable changes.
Getting to this point took four years of joint development by easyJet, Rolls-Royce and several industrial partners. The project also produced advances in hydrogen fuel storage, fuel delivery systems, and the specialist infrastructure needed to handle pressurized hydrogen safely on the ground.
The companies have not announced a timeline for hydrogen-powered commercial flights. Many engineering challenges remain, including how to store enough hydrogen on board an aircraft — hydrogen is much less dense than jet fuel — and how to build the airport infrastructure needed to supply it.
Regulators at EASA (the European Union Aviation Safety Agency) and the FAA (the US Federal Aviation Administration) will need to develop new certification standards before hydrogen-powered aircraft can carry passengers commercially.
easyJet says hydrogen is part of its broader plan to reach net-zero emissions, alongside using newer aircraft, sustainable aviation fuel, and better flight operations. For the wider industry, this test sends a clear signal: hydrogen-powered flight is no longer purely theoretical.
Key vocabulary:
- turbofan – a type of jet engine that uses a large front fan to push air through the engine and produce thrust; it is the most common engine type on modern passenger aircraft
- simulated flight cycle – a test that recreates every stage of a real flight, from engine start-up through takeoff, cruise, and landing, without leaving the ground
- fault scenarios – situations where part of the system deliberately goes wrong, used during testing to check that safety systems respond correctly
- combustor – the section inside a jet engine where fuel mixes with compressed air and burns, producing the hot gases that generate power
- certification standards – official rules set by aviation authorities such as EASA or the FAA that a new aircraft, engine, or technology must meet before it can be used commercially
- net-zero emissions – producing no more greenhouse gases overall than are removed or offset, so that the total effect on the atmosphere is zero
- sustainable aviation fuel (SAF) – fuel made from non-fossil sources such as plant waste or recycled carbon; it can be used in existing engines and produces fewer lifecycle emissions than conventional jet fuel
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