US-UK zero-carbon emissions aviation company ZeroAvia and US carrier Alaska Airlines on Monday announced that they were cooperating in the conversion of the largest aircraft, so far, to zero-emissions propulsion. And at the same time, ZeroAvia unveiled its HyperCore electric motor, which it described as “the world’s most advanced electric motor technology for aviation”.

Alaska Airlines is the fifth biggest US carrier, with a large regional network, making it very interested in the development of non-fossil-fuel-powered zero-emissions regional airliners. It invested in ZeroAvia in 2021, when it also entered a partnership with the hydrogen fuel cell and electric motor (hydrogen-electric) aircraft powertrain development and manufacturing company.

In this new project, Alaska Airlines has handed over to ZeroAvia a 76-passenger twin-turboprop Bombardier Q400 regional airliner, for conversion to hydrogen-electric propulsion. The Q400 was previously operated by Alaska Airlines Group subsidiary Horizon Air. When Horizon retired its Q400 fleet, the group reserved one example specifically for use for zero-emissions aviation research and development.

“Demonstrating this size of aircraft in flight, powered entirely by novel propulsion, would have been unthinkable a few years ago,” highlighted ZeroAvia founder and CEO Val Miftakhov. “Launching this programme puts us on track for a test flight next year, and accelerates our progress toward the future of zero-emissions flight for Alaska Airlines and for the world at large.”

“This is a great step forward in aviation innovation, to help create a new future of flight – right here at home,” affirmed Alaska Airlines CEO Ben Minicucci. “Alaska Airlines has defined a five-part journey to achieve net-zero carbon emissions long-term, but we can’t get there alone. 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 Hypercore electric motor module, unveiled at the same time as the hand-over of the Q400 aircraft, has a capacity of 900 kW. It is a permanent magnet radial flux machine, operating at 20 000 rpm. During recent weeks, at its facility in Hollister, in the US State of California, ZeroAvia has been ground-testing a twin-module Hypercore motor, giving a total power capacity of 1.8 MW, which produces a motor power density of 15 kW/kg, described by the company as “unprecedented”. The system has been tested with a standard Q400 engine gearbox and propellor. Because of its modular design, the Hypercore can be used for applications requiring a power output ranging from 900 kW to 5.4 MW.

ZeroAvia is currently developing its ZA2000 regional aircraft powertrain system, which includes the motor, its in-house developed high-temperature proton-exchange membrane fuel cells, the associated and also in-house developed power electronics, and liquid hydrogen fuel storage. The company has previously flown a 250 kW powertrain and is currently flight-testing its 600 kW ZA600 powertrain, on a modified Dornier Do 228 subregional airliner, in the UK. 

Regarding the conversion of the Q400, ZeroAvia has entered an engineering partnership with original equipment manufacturer De Havilland Canada, to exchange airframe data and expertise. (When the Bombardier group broke up, the unit responsible for the Q400 – also known as the Dash 8-400 – now under new ownership, reverted to its original name.)