Liquid hydrogen is a big challenge, but it is one of the few technologies that has a chance of decarbonizing long-haul flights. Therefore, H2Fly completing the world’s first manned flight over liquid water is big news for sustainable aviation. Green liquid hydrogen is a clean fuel that emits nothing but water when burned, and can be run from a fuel cell to provide instant energy to electric motors. It carries about 2.8 times the energy of jet fuel relative to weight, and that’s a huge difference in the aviation world where every ounce of weight counts.

On the other hand, working out is a bit of a nightmare. For it to remain liquid, you need to keep its temperature close to absolute zero; It boils at only 20 Kelvin (-253°C /-423.4°F) at ambient pressure levels. It may have a high energy content by weight, but its energy density by volume is very low. You need a tank almost four times larger than your typical jet fuel tank to carry the same amount of energy, so some of the weight is lost on heavier equipment.

All things considered, H2Fly says it can double the maximum range of its Pipistrel Taurus HY4 twin-fuselage aircraft from 750 km (466 miles) to 1,500 km (932) when switching from gaseous hydrogen to liquid fuel. shaft). Both of these figures are above what is possible with today’s relatively heavy battery technology.

This aircraft’s peculiar layout allows the pilot to sit in the right fuselage, while the fuel system is kept isolated in the left fuselage. Meanwhile, the electric propulsion system and hydrogen-converting fuel cells are housed in a central engine compartment between them.

The company said it has so far completed not only the world’s first manned flight over liquid water, but also three other missions operated from an airport in Maribor, Slovenia. According to the press release, the aircraft “delivered safe and efficient performance during numerous flight tests” and analysis of test flights supports the expected range performance of the H2Fly.

“This achievement marks a milestone in the use of hydrogen in aircraft propulsion,” said Professor Josef Kahlo, co-founder of H2Fly. — Together with our partners, we have demonstrated the viability of liquid hydrogen to support medium- and long-term emissions-free. Flight. “We now plan to expand our technology to regional aircraft and other applications and embark on the critical mission of decarbonizing commercial aviation.”

Of course, the company did not work alone on this flight, it led a consortium that included Pipistrek Vertical Solutions, Air Liquide, EKPO Fuel Cell Technologies, Fundacion Ayesa and the German Aerospace Center. Funding was also added by two German federal ministries and the University of Ulm.

With technology now proven in small, lightweight, low-altitude test aircraft, H2Fly now continues to scale businesses to the size required for commercial passenger and cargo operations. It is working on a new generation fuel cell modular power supply that can meet megawatt power requirements. The H2F-175 fuel cell is also designed to operate at altitudes up to 27,000 feet (8,200 m), making it suitable for regional aircraft with 20 to 80 seats.

But something like this takes time to be developed, fully tested, logically integrated into airframes and, above all, certified for safe operation by EASA, FAA and other aviation authorities. H2Fly hasn’t put a date on when it plans to put these zero-emission mid-range power plants into commercial service, but we expect the equipment to start using commercial jet fuel in the mid-2030s. budgets Source