Published 11/11/2022

H2fly begins LH2 tank integration into HY4 test aircraft

Liquid tank passes vibration and leakage test, kickstarting the mechanical integration process and rigorous ground testing early in 2023 for zero-emissions commercial flight.

Edited by: Grace Stubbins

Senior Managing Editor, CompositesWorld and Products Finishing

H2fly (Stuttgart, Germany), a spin-off from the German Aerospace Center (DLR) that is developing hydrogen fuel cell systems for aircraft, and its partners, has begun the integration of a liquid hydrogen (LH₂) storage system tank into its HY4 aircraft. The integration process commenced following the tank passing the vibration and LH₂ leakage testing phase at Air Liquide (Paris, France) in September.

The announcement marks a significant step forward for Project HEAVEN — an initiative which has set out to design, develop and integrate a powertrain based on high-power fuel cell and cryogenic technology, into an existing aircraft for testing in-flight operation. The start of the mechanical integration process draws H2fly closer to achieving higher aircraft ranges, which is critical in the pursuit of achieving true zero-emissions medium and long-haul flight.

H2fly supplies the complete fuel cell system supporting the composites-intensive HY4 aircraft, along with the integration platform and the overall system architecture and controls of the fuel cell and hydrogen storage system. As the development lead, H2fly plays a critical role in the complete coordination of the system implementation to guarantee each of the system parts is properly adapted, ensuring safe functionality.

The company is joined by the following partners for the HEAVEN project: Air Liquide Advanced Technologies, a cryogenic tank designer and supplier; Pipistrel Vertical Solutions (Ajdovščina, Slovenia), which will be supporting the integration and demonstration of the tank; and the DLR, supporting the operation and testing of high power fuel cell and system architecture.

Integration work is expected to be completed over the coming months. Following the integration of the new hydrogen storage system and fuel cells, the aircraft is planned to enter a rigorous program of ground testing early in 2023.

“For the past 10 years, at H2fly we have been focused on developing and delivering new technology and now we look forward to completing the integration process so we can begin ground testing in preparation for the world’s first commercial liquid hydrogen-electric aircraft,” Prof. Dr. Josef Kallo, co-founder and CEO of H2fly, says.

The HEAVEN project has received funding from the Fuel Cells and Hydrogen 2 Joint Undertaking (JU) under grant agreement No 826247. The JU receives support from the European Union’s Horizon 2020 research and innovation program and Spain, France, Germany and Slovenia.

For more than 10 years, H2fly has been researching, testing and refining, resulting in the development of the HY4, a four-seat aircraft with hydrogen-electric propulsion, that first took flight in 2016. There have been several key milestones across the past two years, including:

In 2020 H2fly was granted a permit to fly the latest generation of the HY4 aircraft, which featured a fully redundant powertrain architecture. Across more than 90 takeoffs, the company successfully demonstrated the applicability of hydrogen-electric propulsion solutions in aviation.
In 2021, the company signed a strategic partnership with aircraft manufacturer Deutsche Aircraft (Oberpfaffenhofen, Germany) that will see the companies work together to fly a CS25 class aircraft powered by H2fly’s hydrogen fuel cell technology. The climate-neutral regional aircraft, which is expected to fly for the first time as a prototype in 2025, is planned to have a 2,000-kilometer range and seat up to 40 passengers
Earlier this year, the company completed a cross-country flight, from Stuttgart, Germany, to Friedrichshafen, covering 77 miles, marking what it repors is the first time a hydrogen-powered passenger plane has flown between two commercial airports
Also this year, the company set what is believed to be a world altitude record for a hydrogen-air-breathing aircraft, flying at 7,230 feet.