H2FLY, the Stuttgart, Germany-based aviation company focused on developing hydrogen fuel cell systems for aircraft, has successfully cleared liquid hydrogen on-ground filling tests with the newly developed liquid hydrogen tank, which is integrated into its HY4 aircraft.
The HY4 is a four-seat aircraft based on the Taurus G4, manufactured by Pipistrel. The company expects the use of liquid hydrogen (LH2), which is more challenging to handle and store than gaseous hydrogen, to at least double the HY4’s range from 450 to 900 miles.
According to HY4, the integration of a liquid hydrogen tank into the aircraft and successful filling tests is a significant milestone for the program and the world’s first. The work is being carried out as part of the European project HEAVEN, a consortium of five partners to demonstrate the feasibility of using liquid, cryogenic hydrogen-powered fuel cell powertrain in aircraft, led by H2FLY.
The new liquid hydrogen storage system is designed and supplied by its project partner Air Liquide based on H2FLY’s requirements. The filling procedure took place in preparation for the forthcoming coupling tests in which the liquid hydrogen storage system will be coupled with the fuel cell system to form a complete hydrogen-electric powertrain.
“The successful on-ground filling tests today mark the next milestone in our pursuit to doubling the range of our HY4 aircraft,” says Prof. Dr. Josef Kallo, co-founder and CEO of H2FLY. “It is a critical step for our upcoming flight test campaign this summer, which will demonstrate the feasibility of liquid hydrogen as a fuel for medium and long-haul flights.”
Air Liquide’s liquid hydrogen tank passed the vibration and LH2 leakage tests in September 2022 and was fitted into H2FLY’s fuel cell-powered aircraft HY4 in November 2022.
Also, last year, the company set what is believed to be a world altitude record for a hydrogen aircraft, flying at 7,230 feet. The company is also working with aircraft manufacturer Deutsche Aircraft to convert Dornier 328 regional aircraft to run off hydrogen and plans to make the first test flights in 2025.
