Hydrogen is one of several technologies being considered to support the UK’s transition to net-zero aviation. Its use in aircraft and infrastructure introduces new safety, operational and regulatory questions.
Through the Hydrogen Challenge, we are working with industry, academia and government to better understand how hydrogen could be used safely within the UK’s aviation system. Our role is to identify risks, review existing regulations, and help ensure that any future adoption is underpinned by a robust regulatory approach.
About the Hydrogen Challenge
Launched in November 2023 and supported by the Regulators' Pioneer Fund and now Department for Transport, the Hydrogen Challenge aims to:
- Identify safety risks and regulatory gaps linked to hydrogen in aviation
- Conduct targeted trials through our regulatory sandbox
- Collaborate with stakeholders
This work supports the broader Jet Zero Taskforce let by the UK Government.
We are addressing these issues through our challenge using a regulatory sandbox approach to make sure regulation is fit for purpose and reduce challenges associated with the potential introduction of hydrogen fuel.
Our challenge will facilitate collaboration with industry and academia to improve understanding of hydrogen-related risks in aviation, identify gaps in policies, and propose new recommendations to develop net-zero policies.
This will allow for increased regulatory readiness, reduced risk of failure, and improved collaboration with the UK Civil Aviation Authority.
How it works
In February 2024, we announced the first companies selected for the Hydrogen Challenge sandbox - a controlled environment where organisations can test products and services in collaboration with a regulator.
Cranfield Aerospace Solutions, Exeter Airport Consortium and ZeroAvia worked closely with us to increase readiness of industry and the regulator for hydrogen fuel.
In February 2025, a second round of the Hydrogen Challenge was announced, which includes:
- Development of new aircraft designs utilising hydrogen fuel cell power systems and remotely piloted systems
- Modifications to airport infrastructure to accommodate hydrogen, including safe storage and refuelling
- Scientific research by leading UK aeronautical institutes to deepen understanding of hydrogen as a fuel
- Flight trials, safety assessments, and demonstrations to refine performance and address regulatory challenges
Continued funding will support the expansion of the Hydrogen Challenge sandbox from three to thirteen projects.
Learnings from the sandbox activities and our stakeholder working groups will continue to enable the identification of risks, hazards, and appropriate mitigation measures to be implemented. This learning will inform our development of regulation and government policy, including informing the joint government and industry Jet Zero Taskforce
Hydrogen Stakeholder Working Groups
The Hydrogen Challenge Stakeholder Working Groups have been established to facilitate effective engagement, consultation, and collaboration between the UK Civil Aviation Authority and selected governmental, industry, academic and community stakeholders relating to the Hydrogen Challenge.
The three working groups aim to ensure that the development and implementation of the programme align with the needs and expectations of stakeholders and maintain a high standard of safety while promoting efficiency and innovation in relation to using hydrogen as an aviation fuel.
These working groups are co-chaired by industry and will work towards creating policy recommendations in:
- Hydrogen Propulsion
- Hydrogen Safety and Certification
- Hydrogen Aerodromes
Get in touch
For any questions or queries on the Hydrogen Challenge or our work on this topic, please contact hydrogenchallenge@caa.co.uk.