A key milestone has been reached in the switch to zero-emission commercial aviation with the first test flight of a 19-seat hydrogen-electric commuter plane by propulsion system developer ZeroAvia. A Dornier 228 testbed aircraft performed a 10-minute flight from Cotswold Airport in the west of England, jointly powered by hydrogen-electric powertrain on its left wing and a standard Honeywell TPE-331 powerplant on its right. The flight, which is the first of a 10-20 flight test campaign, was conducted as part of the HyFlyer II project, a research programme backed by the UK government to develop a zero-emission 600 kilowatt powertrain for 9-19 seat commuter aircraft, and the Dornier is the largest plane to date to fly with a hydrogen-powered engine. ZeroAvia is targeting 2025 for entry into commercial service. “This is a major moment, not just for ZeroAvia, but for the aviation industry as a whole,” said Val Miftakhov, the company’s Founder and CEO. “It shows that true zero-emission commercial flight is only a few years away.”
The inaugural test flight of the Dornier 228 testbed comes two years after the first of more than 30 flights by ZeroAvia with a six-seat Piper Malibu aircraft, equipped with a 250kW hydrogen electric powertrain. The Dornier will now progress to a series of test flights from Kemble, ZeroAvia’s UK base, then demonstration flights from other airfields as it progresses towards certification for introduction into commercial service. Later this year, to conclude the HyFlyer II project, ZeroAvia will perform a 300-kilometre hydrogen-electric flight with the Dornier test aircraft.
“The first flight of our 19-seat aircraft shows just how scalable our technology is, and highlights the rapid progress of zero emission propulsion,” said Miftakhov. “This is only the beginning. We are building the future of sustainable, zero climate impact aviation.”
The hydrogen-electric powertrain fitted to the Dornier for its first test flight, which ZeroAvia said had been capable of lasting 20-25 minutes and had a take-off weight of 5,650kgs, comprised two fuel cell stacks, with lithium-ion battery packs providing peak power during take-off and landing and added safety backup for the test. Hydrogen tanks and fuel cell power generation systems were installed in the cabin for the flight, though in commercial use these would be stored externally. The powertrain was fuelled with compressed gaseous hydrogen, which was produced with an on-site electrolyser. “All systems performed as expected,” the company confirmed.
The test campaign will include longer endurance flights, including taking the aircraft to a maximum speed, altitude and take-off weight, which Miftakhov said will feed into the final iteration of the design of the engine. Flight test campaigns and demonstration flights, including on the 2 MW powertrain, are also planned for other parts of the world, Gabriele Teofili, Head of Aircraft Integration & Testing, told a post-flight press briefing.
Added the company: “This is the largest ZeroAvia engine tested to date and places the company on a direct path to a certifiable configuration to be finalised and submitted to certification in 2023, with this programme also serving as a key to unlocking speedy technology development for larger aircraft. ZeroAvia’s 2-5 MW powertrain programme, already underway, will scale the clean engine technology for up to 90-seat aircraft, with further expansion into narrowbody aircraft demonstrators over the next decade.”
Certification is the biggest challenge right now, said Teofili. In December, the company secured a Part 121 permit from the UK CAA to test fly the retrofitted Dornier 228. ZeroAvia said it has worked closely with the CAA to meet far more stringent requirements compared to the framework it had used for testing its 6-seat prototype in 2020.
ZeroAvia has announced a range of partnerships with suppliers, airports and recently Air France Industries – KLM Engineering and Maintenance to develop support for the new generation of powertrains. It has also signed agreements with partners including Textron Aviation to develop hydrogen-electric powertrains for Cessna Grand Caravan aircraft, Otto Aviation to power its new airship-shaped craft, and UK-based Monte Aircraft Leasing, which has placed an order for 100 ZA-600 hydrogen-electric powertrains to convert existing and new Cessna Caravans, and to retrofit DH6 Twin Otters, Dornier 228s and HAL 228s to zero-emission propulsion from 2024.
The company is targeting 2026 for certification of the 2-5 megawatt ZA-2000 powertrain, designed to convert 40-80 seat turboprop aircraft to zero-emission propulsion, and the late 2020s for the ZA-2000RJ to re-engine regional jets. It has provisional orders for each from both regional and major airlines, the latter including US giants United Airlines and American, both of which have also invested in ZeroAvia.
In all, ZeroAvia has 1,500 engines on pre-order, 600 to 700 of which are for the ZA-600. Miftakhov told the briefing that a launch operator and launch aircraft type would be announced shortly and expressed confidence the first flight would help bring in further funding from both existing and new investors.
To enable hydrogen production on site for the inaugural flight of the hydrogen-electric Dornier testbed, ZeroAvia and the European Marine Energy Centre (EMEC), also a participant in the HyFlyer II programme, delivered and operated the Hydrogen Airport Refuelling Ecosystem (HARE), to demonstrate on a small scale the infrastructure for green hydrogen production, storage, refuelling and fuel cell powered flight.
ZeroAvia is hard at work on developing the ground infrastructure that will be needed at airports to handle hydrogen-electric aviation and has formed partnerships with energy companies like Shell, as well as with 10 airports that takes into geographical account commitments already received from airline customers. “We believe the best approach to building infrastructure is with on-site production of hydrogen by electrolysis, which avoids transportation of the fuel over long distances,” said Miftakhov. “This is the most economical way to produce the fuel and also the fastest way to deploy the infrastructure. We are quite confident that we will have the infrastructure in place to support our launch.”
Grant Shapps, UK Secretary of State for Business, said the ZeroAvia flight was “a hugely exciting vision for the future – guilt-free flying, and a big step forward for zero emission air travel. It also demonstrates how government funding for projects like these is translating into net-zero growth. The UK is a world leader in green aviation technology, and the global shift to cleaner forms of flight represents a huge opportunity to secure growth and jobs for our country. That’s why we are backing businesses who share our ambitions, reaping the benefits of green technology and growing the thousands of new, skilled jobs that come with it.”
Miftakhov told the press briefing the company was now “in a very mature state” and that the inaugural test flight gave confidence on the timeline for entry into service.
“Aviation has a 3% share of global carbon emissions but 5-10% of humanity’s climate impact through non-carbon sources that can only be effectively addressed by hydrogen-electric and that is why ZeroAvia is focused on this power source. With today’s flight, we have taken a major step in this direction and although we are celebrating the achievement, there is a lot of work still to do.”
Photo: The ZeroAvia Dornier 228 aircraft takes off on its maiden test flight