ZeroAvia’s ZA600 hydrogen fuel cell powertrain may not enter service before 2027, according to the latest certification timeline disclosed by the UK-US developer.
However, the company may see earlier success for its 600kW electric propulsion system (EPS), which appears set to arrive slightly ahead of the complete powertrain.
As recently as July, ZeroAvia said that the ZA600 powertrain would gain certification in late 2025 or early 2026, enabling service entry on the Cessna Caravan later that year.
But responding to questions from FlightGlobal, the firm now says it aims “to complete [type certification] of the full powertrain with the [UK] CAA [Civil Aviation Authority] in around two years’ time”, putting the milestone around late 2026.
“Entry into service would be 2026 or 2027,” it adds.
ZeroAvia has opted to seek certification for the powertrain – comprising the hydrogen-management system, hydrogen fuel cells, power distribution system and the EPS – from the CAA. Approval for the EPS, meanwhile, will be through the US Federal Aviation Administration (FAA).
But certification for the EPS – the electric motor and associated systems being developed at the firm’s site in Everett, Washington – “may be a little ahead” of that for the complete propulsion system, says the company.
Speaking during ZeroAvia’s recent Hydrogen in Aviation Summit, Paul Murphy, chief technology officer for electric propulsion, said it was “on the cusp of certification for the electric engine”.
“That will really kick us off into our longer journey as we scale up into the industry to develop hydrogen electrification,” he says.
With the EPS agnostic to the power source, ZeroAvia sees an opportunity to bring the engine to market sooner, in line with its strategy of becoming a systems supplier to generate near-term revenues and help cut the cost of capital.
While declining to identify any customers, it notes there “are a number of clean-sheet innovators looking at battery power for novel applications that are relevant to this power level [and] design”.
ZeroAvia opted to split the certification of the EPS from the full powertrain as it “wants to capitalise” on the FAA’s familiarity with electric propulsion concepts: the regulator is “a little bit further along in the story with… some of the electrification that’s going on in the world”, says Murphy.
But further regulatory complexity will come as ZeroAvia seeks approval for the launch application on the Caravan via a supplemental type certificate (STC).
It has yet to select the “primary regulator” for the STC – a decision to be made “in due course” which will be driven by the location of the launch customer.
In addition, ZeroAvia appears to be moving away from plans to conduct point-to-point flights with its modified Dornier 228 in the UK.
Fitted with a prototype version of the ZA600 powertrain – including batteries to provide a level of redundancy – the aircraft (G-HFZA) performed 12 test flights from January 2023 to April 2024 but has not flown since.
It had indicated that point-to-point flights would be the next development milestone but now appears to have adapted its plans.
“Our window to achieve this is closing as the priority is certification test-flight programme, so we may not go ahead with the A-to-B flight in the current configuration,” says ZeroAvia.
“As you are aware, this current configuration is a prototype, so we are now focusing on more urgent priorities on our certification and R&D roadmap.”
ZeroAvia has two Do 228s in the UK, having ferried a second example (N409VA) from the USA in June to bolster its flight-test capacity.
It intends to retrofit one of the two aircraft with the “certification-intent powertrain”, although it does not identify the airframe.
“We have a range of other test assets and facilities designed to help us meet the requirements agreed with the CAA, and also to help further R&D for other parts of the technology roadmap,” the company adds.
