Netherlands' aerospace research agency Royal NLR has revealed plans to convert the Pipistrel Velis Electro battery-powered research aircraft for crewed flight testing of fuel-cell propulsion using liquid hydrogen. The fuel-cell system for this initiative will be provided by Zepp Solutions, a Dutch specialist in hydrogen technology. The primary objective of this project is to showcase the feasibility and benefits of hydrogen as a clean energy source for aviation. By experimenting with liquid hydrogen on the aircraft, Royal NLR and its partners aim to contribute to the advancement of technology in the aerospace industry, specifically in terms of sustainable air transport. This development marks a significant step towards exploring alternative energy solutions for the aviation sector, emphasizing the potential of fuel-cell propulsion systems powered by hydrogen for future aircraft.