H2FLY completes first liquid hydrogen flight tests

According to the Stuttgart-based company, a total of four flights were completed using cryogenically stored liquified H2 (LH2) to power HY4’s hydrogen-electric fuel cell propulsion system. With one of the flights lasting in excess of three hours, H2FLY is hailing the achievement as a major milestone on the road to emissions-free passenger flight. It’s claimed the results indicate that using LH2 in place of gaseous hydrogen (GH2) will double the maximum range of the HY4 aircraft from 750 km to 1,500 km.

“This achievement marks a watershed moment in the use of hydrogen to power aircraft,” said Professor Josef Kallo, co-founder 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 decarbonising commercial aviation.”

The LH2 flight tests are the latest instalment of Project HEAVEN, a European-government-supported consortium assembled to demonstrate the feasibility of using liquid, cryogenic hydrogen in aircraft. Compared with pressurised GH2, the use of LH2 enables significantly lower tank weights and volume, leading to increased aircraft range and payload. Led by H2FLY, the consortium includes partners Air Liquide, Pipistrel Vertical Solutions, the German Aerospace Centre (DLR), EKPO Fuel Cell Technologies, and Fundación Ayesa.