In a significant milestone for sustainable aviation, a hydrogen-powered air cab has completed an 842-kilometer flight, emitting only water vapor. The aircraft, which left only a vapor trail in its wake, represents a promising alternative to traditional gasoline-powered jets for medium-distance regional travel.
Joby is one of several companies at the forefront of creating air cab services using vertical take-off and landing (VTOL) vehicles. Initially, the company focused on developing all-electric aircraft with a range of approximately 160 kilometers, intended for urban and intercity transport. Joby recently adapted a prototype of its electric aircraft to operate on hydrogen. Equipped with a liquid hydrogen tank and a fuel system, the modified VTOL successfully completed a flight of 842 kilometers over Marina, California, using only 90% of its hydrogen fuel load.
(Joby accelerated its hydrogen exploration in 2022 with the acquisition of the startup H2Fly, which specializes in hydrogen-powered aircraft. H2Fly had already carried out the first manned flight of an electric aircraft powered by liquid hydrogen last year). Since then, other Californian companies, such as Universal Hydrogen, have also successfully tested hydrogen fuel sources for propeller-driven aircraft, reaching altitudes of up to 3,000 meters and speeds of 315 km/h. However, Joby’s test flight marks the first time that a VTOL aircraft has completed a flight using hydrogen energy.
“Air travel is fundamental to human progress, but we need to find ways to make it cleaner,” said JoeBen Bevirt, CEO of Joby, in a press release. Bevirt pointed out that the company’s hydrogen electric air cab technology has the potential to redefine regional travel, offering a sustainable solution that complements advances in battery electric aircraft.
Hydrogen has already been considered as a viable fuel alternative in several sectors, including cars, trucks and superyachts. The system works by using hydrogen to generate a chemical reaction that charges the aircraft’s fuel cells during flight. This energy powers the engine and turns the propellers, resulting in zero net emissions during operation. Advocates of this technology believe that it can help to significantly reduce CO2 emissions in the transportation sector. In 2022, aircraft were responsible for approximately 2% of global CO2 emissions, according to the International Energy Agency.

(The production of hydrogen energy still faces significant challenges. Currently, hydrogen production is more expensive compared to electric or fossil fuel alternatives and, although various energy sources can be used to extract hydrogen from hydrocarbon molecules, around 95% of the hydrogen produced in the United States comes from natural gas, a significant source of CO2 emissions).
In addition to hydrogen, other alternatives are being explored to make aviation more sustainable. Startups like Elysian are investing in advances in battery technology to develop electric passenger jets capable of carrying 90 travelers for up to 800 kilometers without refueling. Airlines such as JetBlue and Virgin Atlantic are investing in the development of sustainable aviation fuels, which use renewable raw materials and waste products instead of fossil fuels.
The successful flight of Joby’s hydrogen-powered air cab is a significant step towards sustainable aviation. However, tackling the challenge of carbon emissions in aviation will require a combination of several alternative technologies. As demand for air travel continues to grow, it is imperative that the industry invests in innovations that can ensure a cleaner and more sustainable future for air transportation.