GKN Aerospace has significantly scaled back its research and technology activities related to hydrogen propulsion in the wake of Airbus’s decision to delay the launch of any hydrogen-powered aircraft by at least five years.
While one project related to an entire fuel cell powertrain will run its course – ending in the first half of next year – the firm’s future focus will be on cryogenically cooled high-power distribution.
Research into motors, hydrogen fuel tanks and power generation will be discontinued, however.
Although Airbus insists hydrogen remains a serious contender as a future zero-carbon fuel source, the airframer earlier this year said it was slowing – although not stopping – work on its ZEROe project to develop a hydrogen-powered airliner due to technology and infrastructure concerns. Service entry is not expected before 2040 at the earliest.
GKN has been developing multiple hydrogen propulsion systems that it hoped would find their way onto any future Airbus aircraft.
Alongside GKN’s internal R&T spending, and some investment from the Dutch government, funding for three specific projects came from the UK’s Aerospace Technology Institute (ATI).
Started in 2021, H2GEAR is a five-year project to develop a 1MW-class fuel cell powertrain, including a cryogenically-cooled motor; meanwhile, through HyFIVE – led by Marshall Aerospace – GKN has been working on a hydrogen fuel tank as part of a wider fuel system.
These were followed last year by the launch of H2FlyGHT, a £44 million ($60 million) project intended to prepare a 2MW-class cryogenic powertrain for flight-testing.
Although not mentioned at the time the initiative was announced, Airbus had been lined up to carry out the flight tests.
But faced with slower pace of development at its intended “primary customer”, GKN has had to reassess its investment plans and “make some pretty difficult decisions”, says chief technology officer Russ Dunn.
“Unlike Airbus, we don’t make the decision on when a programme is launched; for us, investment in technology is about inspiring the customer and building the confidence and credibility with the customer around our ability to exploit some of those capabilities.
“So, with that in mind, we had to look at the extended timeline and ask ‘what should we be doing?’.”
Following an internal review and consultation with other stakeholders, GKN will “reduce [its] focus down to the things most well-aligned with Airbus’s plans”, says Dunn.
Crucially, this means an end to its £10 million-worth of involvement in HyFIVE: “We are going to stop our work around hydrogen storage,” he says.
Dunn says although the project had been “going really well”, its decision was informed, in part, by Airbus’s in-house development of a fuel tank – a component showcased at the airframer’s summit event in March.
It is unclear if GKN’s HyFIVE industrial partners – Marshall and Parker Meggitt – will continue their work, however.
As H2GEAR was scheduled to wrap up next year regardless, GKN has opted to continue the project until its conclusion. “We are going to see that through,” says Dunn.
GKN’s plans called for the powertrain developed through H2GEAR to be scaled up through the follow-on H2FlyGHT project.
However, GKN has now tempered its ambitions and will drop the power-generation and cryogenic motor elements from the H2FlyGHT effort.
In the case of the former technology, while GKN has “developed some great knowledge and capability on how to control that system and how to make it efficient”, it had been using fuel cell stacks supplied by third parties.
Airbus, notes Dunn, sees power generation as “a really core area” and has already established an aviation fuel cell joint venture, Airbus AeroStack, with Germany’s ElringKlinger.
As such, “realistically we were unlikely to secure a route to exploitation on the platforms coming,” he adds.
Similarly, although GKN sees great potential from its cryogenically-cooled motor – delivering high efficiency and an impressive power-density – it cannot justify the “vast” investment required to develop a flight-worthy solution.
Dunn says there are other companies in the sector with more electrical motor experience who would be “better placed to exploit the concept”.
“We will finish it through H2GEAR and then during that period we will look and consider how we can support others to take those concepts on.” Possible options include a sale or licensing of the underlying IP, he adds.
With these elements eliminated, GKN will “modify the scope of H2FlyGHT” to focus on maturing the cryogenically-cooled electrical distribution system it has developed through H2GEAR.
The system uses helium – cooled by the liquid hydrogen fuel – to bring the electrical distribution system down to -253°C (-423°F). This reduces resistance in the wiring to almost zero, allowing “high power without high voltage”, in turn enabling weight to be removed from the system by using thinner cables with less protective shielding.
Learnings from this programme – the exact shape of which is still to be agreed with the ATI – will then feed into a new Airbus UpNext-led project called ICEFlight, based in the Netherlands, the location of GKN’s centre of excellence for wiring.
Unveiled last month, ICEFlight, part funded by the Dutch government’s Luchtvaart in Transitie programme, is designed to explore the “use of liquid hydrogen as a fuel source as well as a cold source” to “enhance the performance of next-generation aircraft powertrains through the integration of advanced electrical technologies, superconductivity and hyperconductivity.”
These technologies will be matured “in preparation of a flight demonstration”, says Airbus.
Dunn sees the addition of the technology to its already strong electrical wiring and interconnection capabilities as “quite a disruptive step”, with the cryogenic control and cooling elements effectively giving GKN responsibility for a new sub-system.
“The ambition is still to take it to flight, but with Airbus’s revised timeline we will have decide how and when that happens,” he adds.
