Hydrogen-electric propulsion developer ZeroAvia has taken delivery of an ex-Alaska Airlines Bombardier Q400 regional airliner for conversion to a zero-emission flight testbed. The 76-seat turboprop aircraft will be retrofitted to test a prototype of ZeroAvia’s new ZA2000 hydrogen-electric powertrain, which is being developed to provide zero emission propulsion for 40-80 seat aircraft from 2027. The Q400, originally known known as the De Havilland Dash 8-400, was donated by Alaska Airlines, a ZeroAvia shareholder and research partner, whose regional subsidiary Horizon Air recently retired its turboprop fleet. It will become ZeroAvia’s fourth testbed aircraft, following two 19-seat Dornier 228s and a six-seat Piper Malibu, and when operational will be the world’s largest zero-emission aircraft. The jointly-branded Q400 was formally unveiled in a ceremony at ZeroAvia’s research and development site at Paine Field, north of Seattle. The event was also used by ZeroAvia to showcase a new multi-megawatt electric motor system, which was demonstrated by powering a propeller spin on a ground test rig.
The delivery of the Q400 is a significant stride for ZeroAvia, which launched hydrogen-electric flight tests two years ago with a 250kW hydrogen-electric powertrain retrofitted to the Piper Malibu testbed, followed earlier this year by the first flight test of its ZA600 propulsion system on one of the Dornier aircraft. The company is targeting 2024 certification of the ZA600 propulsion system for 9-19 seat regional planes, offering a zero-emission flight range of up to 300 miles (483 kilometres). Entry into commercial service is expected to be in 2025, with this programme also serving as a foundation for development and approval of the derivative ZA2000 propulsion system, to power 40-80 seat aircraft up to 700 miles (almost 1,130 kilometres).
ZeroAvia’s CEO and founder, Val Miftakhov, said the Q400 testbed would help advance his company’s long-range programme to decarbonise regional and medium-haul flights, initially by retrofitting turboprops and regional jets with zero-emission propulsion systems. “Demonstrating this size of aircraft in flight, powered entirely by novel propulsion, would have been unthinkable a few years ago,” he said. “Launching this programme puts us on track for a test flight next year and accelerates our progress towards the future of zero-emission flight for Alaska Airlines and for the world at large.”
Alaska Airlines CEO Ben Minicucci described the imminent Q400 research programme as “a great step forward in aviation innovation, to help create a new future of flight,” and welcomed development of the programme near the airline’s Seattle home base. “Alaska Airlines has defined a five-part journey to achieve net zero carbon emissions long-term but we can’t get there alone,” he said. “New technologies are required to make that future possible and we’re thrilled to partner with industry leader ZeroAvia to make new zero emissions options a reality.”
The hydrogen-electric propulsion system developed by ZeroAvia uses fuel cells to create electricity from hydrogen fuel, which then drives electric motors to turn the aircraft’s propellers. The ZA2000 system to be installed on the Q400 testbed aircraft will include ZeroAvia’s High Temperature PEM fuel cells and liquid hydrogen fuel storage, which are necessary to deliver sufficient energy density for flights by large turboprops. ZeroAvia has established an engineering partnership with De Havilland Canada, the original maker of the Dash 8 range of aircraft, to facilitate the exchange of both data and expertise.
As well as inducting the ex-Horizon plane for conversion to a test platform, ZeroAvia has in recent weeks been testing in California a 1.8MW electric propulsion system configuration with a standard Dash 8-400 engine gearbox and propeller. This was demonstrated at the Paine Field event, with a propeller spin performed on ZeroAvia’s ground test rig, a 15-ton ‘HyperTruck’.
The configuration of this system consists of two ‘HyperCore’ motor modules, each of which is a powerful, high-speed 900kW machine which operates at 20,000 rpm, the same as a typical turbine engine, delivering 15kW/kg of motor power density.
“Crucially,” explained ZeroAvia, “HyperCore’s modular design enables the technology to address applications ranging from 900kW up to 5.4MW, meeting a number of regional turboprop and regional jet requirements. The HyperCores were successfully integrated with the stock Dash 8-400 engine gearbox and propeller, which dramatically simplifies integration into the aircraft as a replacement for a stock turbine engine.
“The development and testing programme will enable the understanding and measurement of system dynamics, calibration of physical and electrical models, and validation of thermal management systems,” the company said. It is also developing silicone-carbide power electronics and hydrogen fuel cell systems which will convert hydrogen to energy to power the electric propulsion system.
As well as engine and testbed aircraft developments, ZeroAvia has established a series of ground-based partnerships this year to progress hydrogen operations at regional airports.
In the Netherlands, the company has joined forces with Shell, Rotterdam-The Hague Airport, and Rotterdam-The Hague Innovation Airport to develop concept operations for hydrogen, and targeting demonstration flights by hydrogen-electric aircraft to European destinations within 250 nautical miles (463 kilometres) of Rotterdam by the end of 2024, ahead of commercial passenger flights by 2025.
ZeroAvia has also partnered with Birmingham Airport in the UK to develop hydrogen refuelling infrastructure to support a domestic ‘green aviation network’, with zero-emission flights operating by mid-decade to destinations including Glasgow, Aberdeen, Belfast and Dublin.
In north-east Sweden, the company has joined Braathens Regional Airlines, municipal energy company Skelleftea Kraft and Skelleftea Airport to develop commercial flights from the airport. They will initially explore opportunities from 2025 using 9- to 19-seat aircraft powered by ZeroAvia’s ZA600 powertrain, followed in 2027 with extended operations by 40-80 seat aircraft using the ZA2000 propulsion system. Braathens operates a fleet of 14 ATR72 turboprops, one of the candidate aircraft for the larger powertrain.
ZeroAvia has also signed a Memorandum of Understanding with Nordic energy group Fortum to examine opportunities for hydrogen production and refuelling at airports, not just for air transport but also to support activities including heavy transportation, materials handling and other energy-consuming systems. It has entered a similar partnership with French company Absolut Hydrogen to assess production and storage of liquid hydrogen at airports, as well as refuelling for aircraft of up to 80 seats by 2027.
Top photo: The Q400 painted in a ZeroAvia/Alaska livery
Bottom photo (both photos Joe Nicholson – Alaska Airlines): ZeroAvia’s 15-ton HyperTruck ground-test rig