Clean Aviation now has 53 projects on its books, representing roughly €3.6 billion in research and innovation spending, after the EU body on 17 September announced the 19 industry-led projects selected under its fourth call for proposals.

Those projects will share €290 million ($326 million) in EU grants. Yet the announcement has brought no breathing space for the public-private undertaking. Its team faces a packed year-end: grant preparation for the call 4 winners, preparation of the fifth and final call ahead of a February launch, and the wrap-up of the first call 1 projects, which began in January 2023.

Behind all that sits the lobbying effort to shape whatever follows Clean Aviation when the joint undertaking ends in December 2031.

What does the portfolio look like?

The €3.6 billion total combines €1.47 billion of EU grants with private-sector investment. Clean Aviation has two linked objectives: developing next-generation technologies able to cut greenhouse gas emissions by 30% against a 2020 baseline, and maturing them — industrially as well as technically — for entry into service by 2035.

Those technologies feed four aircraft concepts:

• a short- and medium-range aircraft, effectively a new narrowbody;
• an ultra-efficient regional aircraft, a next-generation turboprop;
• a hydrogen fuel-cell aircraft;
• a hydrogen-combustion aircraft.

Most contributing technologies should reach technology and certification readiness levels (TRL/CRL) 6 between 2028 and 2030.

Why does call 4 tilt towards hydrogen?

Call 3, announced last year, funded 12 projects concentrated on the narrowbody and hybrid-electric workstreams; hydrogen was avoided because the predicted service-entry date had shifted. Call 4 corrects the balance. Seven hydrogen-related projects were selected, four of them in the dedicated hydrogen workstream, sharing €101 million of EU funding — nearly matching the €106 million going to the four short/medium-range projects.

"What is important, and it was acknowledged by our technical committee, is that we need to keep investing in hydrogen technology," said Maria Calvo, head of unit project management. "That's why the volume that you can see in call four is similar to SMR… because we need to be prepared for entry into service beyond 2035."

Sebastien Dubois, head of unit, programme development and communications, said the body was "very pleased" with both submission quality and participation: the 19 projects involve 180 organisations, 74 of them new to the programme. Some 42% of funding goes to research organisations, universities and SMEs.

How do projects build on earlier work?

Calvo stressed "crossover" — call 4 projects stacking on phase 1 results. FARMAN brings Safran and Rolls-Royce together on a hydrogen distribution system for direct-combustion aircraft, building on the HYDEA and CAVENDISH projects. Airbus and MTU Aero Engines are collaborating on EHPIC, a fuel-cell project drawing on HEROPS and FAME; the two companies are meanwhile forming a joint venture in the same field.

"We see the news about the new joint venture stimulated by getting to know each other within our programmes, sharing challenges," Calvo said.

The selection has produced losers as well. Clean Aviation funded three fuel-cell projects in phase 1 — FAME (Airbus), HEROPS (MTU) and NEWBORN (Honeywell Aerospace) — but could fund only one in call 4. Honeywell missed out; Dubois said EHPIC scored better against the assessment criteria, but "it doesn't mean that there is no further room for continuation", possibly through other funding routes or a successor programme.

Elsewhere, two hybridisation projects for next-generation ducted-fan engines were funded — ELEVATED, led by Rolls-Royce, and HEURECA, led by MTU — although the call allowed up to three. Both will deliver ground demonstrators at TRL5, with the "opportunity" of flight-test continuation in call 5.

What happens next?

Whether both engines reach flight test remains undecided. "Will there be two projects being financed or only one? I cannot tell you," Dubois said. "Definitely there is the will to have at least one ducted fan concept being matured and developed up to TRL6 as a minimum."

Call 5, worth around €230 million, will likely target industrialisation and manufacturability of major propulsion components — fans, gearboxes, transmissions — plus battery research with an integrated battery management system and up to eight 'fast-track' projects. Clean Aviation's governing board confirms focus areas in early December, publishes the call in February, and sets a May submission deadline.

Beyond 2031, the European Commission has listed "Smart and Clean Aviation" among 11 moonshot priorities for its next multi-annual financial framework, potentially covering both aircraft technologies and air traffic management, and adding an all-electric aircraft of up to 19 seats to the concept portfolio. Draft regulation is due in March.

Dubois hopes the successor will carry technologies from TRL1 to TRL9 and bridge the 'Valley of Death', using loans or grants to scale up proven technologies and finance production lines — sustaining, as he put it, EU supply-chain capabilities "in order to avoid having those outside Europe".