The UK Civil Aviation Authority has launched the second round of its Hydrogen Challenge to prepare the aviation industry for a net zero fuel future. The challenge, which began in 2024, focuses on hydrogen propulsion testing, airport infrastructure development, and innovating aircraft systems. Through collaborations with multiple UK companies, the CAA aims to trial and develop technology and infrastructure supporting widespread hydrogen fuel use in aviation. This initiative is set to cover trials spanning three years to boost the development potential of the participating companies. Tim Johnson, the director of communications, strategy, and policy, expressed optimism about the trials positioning the UK as a global leader in hydrogen propulsion. The results from the 2024 Hydrogen Challenge will be disclosed soon, with the subsequent stage featuring the development of cutting-edge aircraft designs powered by hydrogen fuel cell systems. The projects under the Hydrogen Challenge will not only enhance understanding of hydrogen technologies but also shape future regulations to ensure safe adoption in the aerospace sector. Key initiatives include testing hydrogen fuel cell electric propulsion systems, exploring hydrogen combustion challenges, and developing high-altitude hydrogen-powered aircraft for various applications. Several companies like Cranfield Aerospace Solutions, Oxford University, ZeroAvia, Qdot Technology, Stratospheric Platforms, Rolls-Royce, Intelligent Energy, and others are actively involved in different aspects of advancing hydrogen technology in aviation. These projects encompass testing regulations for hydrogen fuel systems, exploring scientific challenges of hydrogen combustion, and developing long-range unmanned aircraft powered by hydrogen, among other innovative endeavors.