Clean Aviation Calls For Research and Innovation Proposals

The European Union-backed Clean Aviation project has announced its fourth call for proposals, with an initial draft published on December 9 set to be followed by formal proposals that will be issued on Feb. 13, 2026. The upcoming call will provide up to €329.5 million ($386 million) in funding for disruptive new aircraft technologies, providing an estimated €824 million ($966 million) when combined with input from the private sector.

The Call 4 stage of Clean Aviation Strategic Research and Innovation Agenda is seeking proposals for three specific projects, each with their own funding allocations. These include ultra-efficient short-medium range aircraft (€130 million), hydrogen-powered aircraft (€101 million), and ultra-efficient regional (€40 million). Separate pots of money will be available for what the organization calls fast-track areas (€40 million) covering technology such as low-power ice protection systems and transverse activities (€18.5 million) for work including certification methodologies.

Speaking at the Future Aviation Festival in early December, EU Clean Aviation executive director Axel Krein explained the scope of the next round. The research and technology roadmap focuses on developing demonstrator technology up to the ground testing stage, validating performance up to technology readiness level six.

Flight demonstrations could also be used to validate testing “in realistic operational conditions.” Clean Aviation expects to complete a flight test demonstrator configuration freeze by the end of 2026 to support a start of flight testing by the end of 2029.

A hybrid-electric ultra-efficient regional aircraft has been proposed as the baseline concept for this 50-100 passenger regional aircraft. Clean Aviation will also award €40 million for the development of an “advanced airframe for ultra-efficient regional aircraft.”

The inclusion of hydrogen-related projects (notably absent in Call 3) marks a desire to help mature a technology Clean Aviation stated has faced “delays and slower progress.” The €101 million funding will be used to support the “demonstration of an integrated hydrogen fuel system for a fully electric hydrogen fuel cell powered aircraft” and to demonstrate “advanced fuel cell propulsion techno-bricks for the fully electric hydrogen fuel cell aircraft concept.” Both hydrogen combustion and full cell propulsion systems will be assessed, with two hydrogen-powered aircraft concepts to be considered.

According to Clean Aviation, the related development of a hydrogen ecosystem system for aviation has been slower than expected. The organization now projects the entry into service of hydrogen-powered concepts to shift forward from 2035 to 2040, as has already been acknowledged by Airbus with its shift in timeline for the ZeroE project to develop hydrogen airliners.