20 Jul 2026

Modified Pearl 15 jet engine runs on 100% hydrogen through simulated flight cycle

Energy and storageExperimental cross-disciplinary systems
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

What was demonstrated

The UK Civil Aviation Authority reported on 20 July 2026, in findings from its Hydrogen Challenge, that Rolls-Royce, working with easyJet, modified a Pearl 15 engine to run on 100% hydrogen up to take-off thrust, and across a fully simulated flight cycle. The release says valuable safety and performance data were collected. It gives no thrust values, test durations, temperatures or performance figures. The test was a simulation of the flight stages, not a flight of an aircraft.

Why it matters

The result suggests a Pearl 15 engine can run on hydrogen through the simulated stages of a flight, which may inform engine safety and performance work for hydrogen combustion aircraft. It does not show that a passenger aircraft can carry or refuel hydrogen safely.

Caveats

  • The test was a simulated flight cycle on an engine, not a flight of an aircraft.
  • The release gives no thrust values, durations, temperatures or emissions data, so it does not show how the engine on hydrogen compares with the same engine on conventional fuel.
  • A Rolls-Royce engineer quoted in the release says hydrogen propulsion means establishing new safety standards, often beyond the scope of current rules.
  • The release does not report emissions, so it does not show the climate effect of running this engine on hydrogen.

Technology profiles

Sources

  1. government report
    Regulator publishes report marking important progress towards hydrogen aviation in the UK
    UK Civil Aviation Authority, 20 Jul 2026.

Last reviewed 22 Oct 2026.