MARIBOR, Slovenia—H2FLY GmbH, a subsidiary of Joby Aviation Inc., recently completed the world’s first piloted flight of an electric aircraft powered by liquid hydrogen. A state-of-the-art fuel cell system enabled the HY4 plane to make test flights of up to three hours in duration. The twin-fuselage, four-seat aircraft is modified from the Taurus G4 produced by Pipistrel, a subsidiary of Textron Inc.

The successful test flight was part of Project HEAVEN, a European consortium created to demonstrate the feasibility of hydrogen-powered aircraft. Using cryogenically-stored liquid hydrogen instead of gaseous hydrogen enables significantly lower tank weight and volume, leading to longer range.

“This achievement marks a watershed moment in the use of hydrogen to power aircraft,” says Josef Kallo, Ph.D., CEO of H2FLY. “Together with our partners, we have demonstrated the viability of liquid hydrogen to support medium- and long-range emissions-free flight.

“We are now looking ahead to scaling up our technology for regional aircraft and other applications, beginning the critical mission of decarbonizing commercial aviation,” explains Kallo.

“H2FLY are pioneers in their field, and we’re proud of them achieving this watershed moment in the use of liquid hydrogen to power aircraft,” adds JoeBen Bevirt, CEO of Joby Aviation. “In the years to come, battery-electric and hydrogen-electric propulsion systems will enable us to build aircraft that are quieter and make mid-to-long-range air travel possible with zero emissions. It’s critical we take action now and invest aggressively in these technologies for the health of our planet and future generations to come.”