Joby Aviation, based in the United States, is making significant advancements in the development of hydrogen-electric aircraft alongside its certification process for battery-powered air taxis. The company has transformed its pre-production prototype S4 into a hydrogen-electric technology demonstrator, showcasing increased range and endurance compared to its battery-electric counterpart. During flight testing conducted in June over Marina, California, the aircraft completed a 523-mile journey with 10% of its liquid hydrogen fuel remaining, highlighting the potential for medium- and long-distance flights. By integrating a series-hybrid battery/hydrogen-electric propulsion system, Joby Aviation has demonstrated the power of electric propulsion in creating flexible and efficient aircraft architectures. The vertically integrated approach of Joby, along with the acquisition of hydrogen-electric specialist H2Fly, has streamlined the development process. The company's CEO, JoeBen Bevirt, emphasizes the strategic advantage of this technology, stating that hydrogen-electric aircraft complement battery-electric models, offering operational efficiency for longer flights. With a focus on hydrogen's lighter weight and efficient energy conversion, Joby envisions a future where battery-electric aircraft serve short-distance trips within metropolitan areas, while hydrogen-electric models cater to regional journeys. The company's innovative approach not only expands the capabilities of air taxis but also leverages existing infrastructure and investments for enhanced operational efficiency. Joby's advancements in hydrogen-electric propulsion signify a promising future for sustainable aviation, with the potential to revolutionize air travel through increased range capabilities and operational flexibility.