First hydrogen-powered four-seater makes maiden flight in Maribor
The world's first liquid hydrogen-powered four-seater, a product involving the Slovenian aircraft maker Pipistrel, made its maiden flight at Maribor airport on 7 September in what is considered a major milestone in zero-emission aviation.
The H2FLY HY4 aircraft has been developed by the German company H2FLY in cooperation with Ajdovščina-based Pipistrel and the French industrial gas supplier Air Liquide.
Josef Kallo, the founder and CEO of H2FLY, said that this milestone made the partners in the Heaven project pioneers on the way to emission-free aviation.
The flight is a result of four years of work whose goal it was to prove that it is possible to use fuel cells and a liquid hydrogen storage system to propel an electric aircraft motor.
"We have come so far that we can realistically think about devising this type of propulsion for a 40-seater aircraft," Kallo said, noting that this would require a hydrogen electric fuel cell with the power of one megawatt.
"This would enable flights up to 2,000 kilometres in the future," he said, adding that the plan was to develop such a system in the next four years, after which it will take some time to obtain the required certificates.
A flight with a hydrogen-powered aircraft was first made in 2016, but this aircraft did not have a tank for liquid hydrogen, and was able to fly only up to 700 kilometres.
The innovation developed by Air Liquide enables a range of 1,500 kilometres, and the range is expected to be extended by an additional 500 kilometres in the next phase.
"A test was performed here on 4 September and the previous record of two hours from 2020 was extended to three hours of continuous flight," said the head of the company, whose project has been financially supported by the German federal government.
The project is also supported by private investors and with EU funds, with a significant part also being contributed by the University of Ulm, whose Institute for Energy Conversion and Storage is headed by Kallo.
According to him, the first flight of a 40-seater liquid hydrogen-powered aircraft for commercial purposes would not be possible before 2029 or 2030. He sees opportunities mainly on short routes in Europe.
Asked about certain environmental disadvantages of liquid hydrogen, especially the fact that it requires more energy to produce it than it provides itself, Kallo noted that green hydrogen was used for the project.
About €4-5 million has so far been invested in the project, and the plan is to invest at least five times as much into development.
Air Liquide director of innovation Pierre Crespi said that his company strongly believed in the potential of hydrogen on the way to a zero-carbon future of the aviation sector, which was what motivated the company to join the project.
As part of the project, Pipistrel adapted the airframe for the installation of the liquid hydrogen tank and related systems, helped obtain a permit for the test flight from the Slovenian authorities, and organised the flight.
Marco Rizzato, the head of testing at Pipistrel, said that the company also controlled and interpreted the data obtained on the ground and during the flight.
The data will be analysed and included in studies on the feasibility of upgrading the developed liquid hydrogen-powered propulsion unit for application in larger aircraft.
"We have been developing electric aviation for a long time, but liquid hydrogen as a power source certainly has great potential as well, so it is very important for us to be part of this project," Rizzato said.
The first official test flight was conducted by German pilot Johannes Anton Garbino and Poland's Pawel Adamczuk, who noted that the largest difference compared to ordinary aircraft is the much more silent operation.