Hydrogen aircraft

Also known as Hydrogen aviation, Hydrogen-electric aircraft, Hydrogen fuel-cell aircraft

Hydrogen aircraft would use hydrogen either in a fuel cell that drives electric propellers or in a modified gas turbine. Engine and fuel-cell tests, an uncrewed drone flight and airport ground trials have taken place, but no hydrogen passenger aircraft has entered service and the climate benefit depends on how the hydrogen is made.

Research and prototypesDemonstratedReviewed 21 Oct 2026
AI illustration · Illustrative scene, not a photograph of the specific device or experiment.

In plain language

An aircraft can use hydrogen in two main ways. In one, a fuel cell mixes hydrogen with oxygen from the air to make electricity, which then drives electric motors and propellers. The only product from the fuel cell itself is water. In the other, hydrogen is burned in a modified jet engine, which works more like today's aircraft engines but needs a different fuel system.

Hydrogen holds a lot of energy for its weight but takes up far more space than jet fuel, so the fuel must be stored in large tanks. Liquid hydrogen has to be kept very cold, and the tanks affect the shape and seating of an aircraft and the layout of airports. Trials so far have been small: a modified Rolls-Royce engine has run on pure hydrogen in simulated flight-cycle tests, hydrogen ground vehicles have supported an aircraft turnaround at an airport, and a fuel cell has powered an uncrewed drone. None of these shows that a passenger aircraft can carry hydrogen safely.

Technical explanation

A hydrogen fuel-cell aircraft converts the chemical energy of hydrogen directly into electricity at the stack, without combustion. The power system then has to meet the demands of take-off and climb, manage waste heat, and keep high-voltage electronics isolated. Airbus's ZEROe concept, which Airbus announced in 2025 had selected hydrogen fuel-cell technology as its propulsion method, shows four propellers, each driven by its own fuel-cell stack. Airbus reports that in 2023 its fuel-cell demonstrator completed a test campaign and was powered on at 1.2 megawatts. That was a demonstrator test, not a flight of the proposed aircraft.

A hydrogen combustion aircraft burns hydrogen in a gas turbine. Rolls-Royce and easyJet ran a modified Pearl 15 engine on 100 per cent hydrogen up to take-off thrust and through a simulated flight cycle, according to the UK Civil Aviation Authority (CAA). Combustion avoids carbon dioxide from the fuel but can produce water vapour and nitrogen oxides, depending on conditions. Fuel-cell and combustion routes have different efficiency, heat, maintenance and certification issues, so evidence from one should not be read as evidence for the other.

Storage is the main design constraint for either route. Liquid hydrogen needs cryogenic tanks with insulation, and heat leaking into the tank can raise pressure, so venting may be needed. Airport handling adds further requirements, including supply, leak detection, fire protection and staff training. The CAA's Hydrogen Challenge is a regulatory sandbox in which companies, researchers and the regulator test practical cases. Its third round, announced on 3 September 2026, includes projects on hydrogen-electric turnaround at a busy airport, on cryogenic compressed hydrogen storage, and on airside hydrogen supply.

What the evidence says

Each statement is typed by the strength of its evidence and linked to the source that supports it.

Demonstrated Shown in a published experiment, test or shipping product.

Rolls-Royce and easyJet ran a modified Pearl 15 engine on 100 per cent hydrogen up to take-off thrust and through a simulated flight cycle. The test was a simulated flight cycle, not a flight of an aircraft.

Sources: [1] · Rolls-Royce Pearl 15 paragraph

At Exeter Airport, hydrogen-powered ground equipment supported a TUI aircraft turnaround in April 2025. Later winter and night tests indicated the equipment could operate safely in a live airport environment.

Sources: [1] · Exeter Airport paragraph

Cranfield Aerospace Solutions tested a hydrogen fuel-cell power system on its Stingray drones, and the work highlighted the importance of fuel-cell temperature management.

Sources: [1] · Stingray drone paragraph · medium confidence

The UK CAA's Hydrogen Challenge has eleven organisations collaborating with the CAA on hydrogen-related safety risks and regulatory readiness.

Sources: [2] · Catalogue record summary

The third round of the CAA's Hydrogen Challenge, announced on 3 September 2026, includes a project with Beyond Aero, London City Airport and the University of East London to study hydrogen-electric aircraft turnaround at a busy airport.

Sources: [3] · Third-round project list

Reported, unverified Stated by a company or team but not independently confirmed.

Airbus reports that in 2023 its fuel-cell demonstrator completed a test campaign and was powered on at 1.2 megawatts. The source describes a demonstrator test, not a flight of the proposed aircraft.

Sources: [5] · Demonstrator and context section · medium confidence

Airbus says that in 2025 it announced hydrogen fuel-cell technology had been selected as the propulsion method for its ZEROe aircraft, and that the concept has four propellers, each powered by its own fuel-cell stack.

Sources: [5] · Propulsion choice and Design sections · medium confidence

Proposed A design or plan that has not yet been built or tested.

Airbus and MTU Aero Engines intend to form a joint venture to develop hydrogen fuel-cell propulsion, expected to start operations in 2027. The agreement is non-binding and subject to standard regulatory approvals.

Sources: [6] · Binding status and Expected start

The UK CAA's regulatory roadmap sets out a pathway for the regulator to support scaling hydrogen operations for small aircraft by 2035. This is a regulatory readiness pathway.

Sources: [1] · 2035 roadmap paragraph · medium confidence

Limitations and open problems

  • Engine and fuel-cell tests do not show that a passenger aircraft can carry hydrogen safely, complete a commercial route or meet a full certification basis.
  • Liquid hydrogen needs large insulated tanks kept near cryogenic temperatures, and the sources checked for this profile do not give verified tank volume, mass or boil-off figures for any proposed passenger aircraft.
  • Airport handling of hydrogen needs its own supply, storage, leak detection and emergency procedures, and the UK sandbox projects are intended to build evidence rather than to approve operations.
  • Lifecycle climate benefit depends on how the hydrogen is produced and delivered. Airbus says its fuel-cell aircraft would be almost carbon-neutral only if renewable energy produces the hydrogen.
  • Non-CO2 climate effects, including water vapour and contrails, need assessment. The sources checked for this profile do not quantify them.
  • The Airbus and MTU Aero Engines joint venture is non-binding and subject to regulatory approvals, so its planned start in 2027 is not confirmed.

Possible future uses

Speculative

Ideas, not predictions. None of these has been demonstrated.

  • Small hydrogen-electric business or regional aircraft, if certification and airport supply are resolved.
  • Hydrogen-powered uncrewed aircraft supported by airside hydrogen storage, a use that Saxon Air's sandbox project is intended to inform.
  • Large commercial fuel-cell aircraft with several propellers, as Airbus has described in its ZEROe concept, if tank volume and power-to-weight challenges can be met.

Timeline

  1. 2020Airbus launches its ZEROe project to compare hydrogen propulsion options. Sources: [5]
  2. 2023Airbus reports that its fuel-cell demonstrator was powered on at 1.2 megawatts during a testing campaign. Sources: [5]
  3. Nov 2023The UK CAA launches its Hydrogen Challenge regulatory sandbox. Sources: [4]
  4. Apr 2025Hydrogen-powered ground equipment supports a TUI aircraft turnaround at Exeter Airport. Sources: [1]
  5. 7 Jul 2026Airbus and MTU Aero Engines announce a non-binding intention to form a joint venture for hydrogen fuel-cell propulsion. Sources: [6]
  6. 3 Sept 2026The UK CAA announces three selected projects for the third round of the Hydrogen Challenge. Sources: [3]

Futures this could help bring about

AI illustration
How far away?

Hypersonic passenger flights

Science demonstrated · 4 of 7 steps done

Related breakthroughs

Glossary

Fuel cell
A device that combines hydrogen and oxygen electrochemically to make electricity, releasing water rather than burning the fuel.
Liquid hydrogen
Hydrogen cooled to a very low temperature so that it becomes a liquid. It stores more hydrogen in a given volume but needs insulated, cryogenic tanks.
Boil-off
The gas produced when heat leaks into a cryogenic tank and the liquid evaporates, which can raise pressure and may need to be vented.
Regulatory sandbox
A controlled setting in which companies test products or services with a regulator present, so that both sides can identify safety risks and gaps in rules.

Sources

  1. government report
    Regulator publishes report marking important progress towards hydrogen aviation in the UK
    UK Civil Aviation Authority, 20 Jul 2026. Accessed 21 Oct 2026.
  2. government report
    UK CAA Hydrogen Challenge Hydrogen Sandbox Summary Report 2025/2026 (CAP3284)
    UK Civil Aviation Authority, 20 Jul 2026. Accessed 21 Oct 2026.
  3. news
    Cryogenic storage, aircraft turnarounds and airside supply tech make next round of Hydrogen Sandbox
    UK Civil Aviation Authority, 3 Sept 2026. Accessed 21 Oct 2026.
  4. government report
    Regulating hydrogen use in aviation
    UK Civil Aviation Authority, 2026. Accessed 21 Oct 2026.
  5. company announcement
    ZEROe: our hydrogen-powered aircraft
    Airbus, 2026. Accessed 21 Oct 2026.
  6. company announcement
    Airbus and MTU Aero Engines to create a JV dedicated to hydrogen fuel-cell propulsion
    Airbus, 7 Jul 2026. Accessed 21 Oct 2026.

Revision history

3 changes since this profile was created.

Changes on 21 Oct 2026
Published on owner instruction (content loop iteration 7)fd22377
Sources and claims re-checked against originalsfbb434c
Initial profile drafted from Codex research note and primary sources0eba374

What it took to get here

The inventions this technology was built on, oldest foundations at the top. Lines show what each one required.

Built on: Hydrogen aircraft Unlocked Being researched Locked
  1. 2023Electrolysers for low-carbon hydrogenPilot and early commercial Unlocked.
  1. 2020Hydrogen aircraftResearch and prototypesRequires: Electrolysers for low-carbon hydrogen. Being researched.