H2FLY, the developer of hydrogen fuel and sustainable technologies for aviation, reached a milestone recently, successfully completing the world’s first piloted flight of a liquid hydrogen-powered electric aircraft. The flight was part of a series of test campaign flights conducted by the Stuttgart, Germany-based company.

The flights were performed by the developer’s HY4 demonstrator aircraft, a piloted plane equipped with a hydrogen-electric fuel cell propulsion system. The company said the flight lays the foundation for long-range sustainable flights powered by liquid hydrogen.

Professor Josef Kallo, a Co-founder of H2FLY, spoke about the company’s accomplishment on Thursday.

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