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UK Civil Aviation Regulations

These are published by the CAA on our UK Regulations pages. EU Regulations and EASA Access Guides published by EASA no longer apply in the UK. Our website and publications are being reviewed to update all references. Any references to EU law and EASA Access guides should be disregarded and where applicable the equivalent UK versions referred to instead.



We launched a CAA-led regulatory challenge in November 2023 for fifteen months with an aim to deliver policy recommendations; publish identified risks, challenges, hazards and opportunities to using this type of fuel within an aviation environment; conduct regulatory sandbox test trials; and establish focused stakeholder working groups.

The Hydrogen Challenge is funded with nearly £940,000 from the Regulators' Pioneer Fund, which is overseen by the Department for Science, Innovation, and Technology. 

Hydrogen propulsion

Introducing hydrogen propulsion is key to achieving the UK Government’s jet zero strategy and is also a key deliverable for the UK Civil Aviation Authority’s environmental sustainability strategy.  However, its use as an aviation fuel is at an early stage of development and the sector does not yet have a comprehensive understanding of the potential risks to aviation safety this type of fuel may have nor the right pathway to certification.  

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.

Readiness levels of hydrogen technology landscape

On, 23 November 2023, we launched a survey inviting regulators, industry and academia to complete our survey to gain an understanding of the readiness levels of the hydrogen technology landscape and potential entry into service dates.

Below is a sample list of questions asked within the survey:

  • What areas are being researched?
  • What is the technology or innovation being developed?
  • To provide a short description of the technology / innovation.
  • To provide any high-level risks / safety hazards that this technology / innovation may present.
  • Understanding of intention to certify and location of the technology or innovation.

The findings gathered from this survey have been released and will help shape the future for designing policy and regulatory oversight.

Regulatory sandbox for hydrogen as an aviation fuel

On, 28 February 2024, we announced the first chosen companies selected for the hydrogen challenge sandbox.  Cranfield Aerospace Solutions, Exeter Airport Consortium and ZeroAvia will work closely with us to increase readiness of industry and the regulator for hydrogen fuel. 

We will publish details and outcomes of the sandbox at the end of the challenge.

For any questions or queries on the challenge or the work of the CAA on this topic please contact hydrogenchallenge@caa.co.uk.