From open fan to hybrid-electric: the 12 EU Clean Aviation projects shaping Europe’s future aircraft
September 21, 2025
The European Union has taken another major step towards cleaner skies with the announcement of €945 million in funding for a new wave of research and demonstration projects under its Clean Aviation Joint Undertaking.
Approved on 9 September, the investment will support 12 projects that promise to push the boundaries of propulsion, systems, and aircraft design.
This third call for proposals represents the largest single package to date under the Clean Aviation programme, which falls within Horizon Europe. It is designed to accelerate the development of next-generation regional and short-medium range aircraft capable of cutting greenhouse gas emissions by at least 30% compared with 2020 technology.
Work on the projects is due to start at the beginning of 2026, with first flight tests expected in the 2028–2029 timeframe. By laying the groundwork for new aircraft entering service around 2035, the initiative is a central pillar of Europe’s aviation decarbonisation roadmap.
The €945 million pot combines EU grants with industry contributions and in-kind support. It has been divided between large demonstration programmes for regional and short-medium range aircraft, a set of “Fast Track” enabler projects, and transversal studies into aircraft concept integration and environmental impact.
“The results of Call 3 show the variety of innovative technological concepts to boost the entry-into-service of highly efficient aircraft by 2035,” says Axel Krein, Executive Director of the Clean Aviation Joint Undertaking. “These projects have high potential to make major advancements towards climate neutrality and sustainability.”
Collectively, the 12 winners represent a blend of established OEMs, engine makers, electrical specialists, and smaller innovators, all aligned behind the EU’s climate ambitions.
The EU Clean Aviation chosen dozen
TAKE OFF
Led by Safran Aircraft Engines, TAKE OFF – Technology And Knowledge for European Open Fan Flight – will push forward open fan architecture engines. This disruptive engine design promises significant improvements in propulsive efficiency and is one of the most visible bets on how the next generation of single-aisle aircraft might take shape.
LEIA
Airbus Operations GmbH is coordinating LEIA, the Large scalE Integration demonstrator of hybrid electrical Architecture. The programme will explore how large-scale hybrid-electric power architectures can be integrated into commercial aircraft, bringing together multiple propulsion and energy systems in a single demonstrator.
UNIFIED
Rolls-Royce plc is taking forward UNIFIED, or Ultra Novel and Innovative Fully Integrated Engine Demonstrations. The project will develop and integrate advanced propulsion technologies into a next-generation powerplant concept, paving the way for more efficient and lower-emission short-medium range aircraft.
PHARES
PHARES – Powerplant Hybrid Application for Regional Segment – is coordinated by Pratt & Whitney Canada. It combines a turboprop engine derived from the PW127XT with a powerful electric motor and optimised gearbox. The ambition is to cut regional aircraft fuel burn by around 20%, with a consortium that also includes ATR and Collins Aerospace.
DEMETRA
ATR leads DEMETRA, the Demonstrator of an Electrified Modern Efficient Transport Regional Aircraft. The project will create a flight demonstrator as part of ATR’s broader Evo programme, advancing its ambition to deliver hybrid-electric aircraft to the market in the next decade.
OSYRYS
Safran Electrical & Power is behind OSYRYS – On-board SYstems Relevant for hYbridization of Regional aircraftS. The project will focus on developing and testing the electrical systems required to make hybridisation feasible on regional aircraft, from power distribution to thermal management.
CRYOSTAR
CRYOSTAR, led by the Università degli Studi della Campania Luigi Vanvitelli, will concentrate on the certification roadmap for cryogenic liquid hydrogen tanks. By investigating crashworthiness and safety methodologies, it aims to clear a critical regulatory hurdle for hydrogen-powered aviation.
MODABAT
Germany’s Fraunhofer Gesellschaft will run MODABAT – Modular, scalable and technology-Open Design for future Aviation BATteries. This fast-track project will look at ways of designing modular and scalable battery systems that can be adapted for different aviation applications.
POWER4AIR
Spanish SME Skylife Engineering leads POWER4AIR, which targets the challenges of arc fault detection, electromagnetic interference and reliability in high-voltage power electronics. These are essential elements for making electric and hybrid-electric propulsion safe and certifiable.
LIME
French start-up Ascendance Flight Technologies will coordinate LIME – Lithium based Innovation for Modular Energy. The project is expected to explore lithium-based modular energy systems that can be scaled and integrated into aircraft designs.
HERACLES
HERACLES – Hybrid Electric Regional Aircraft Concept for Low EmissionS – is another ATR-led project. Unlike DEMETRA, which is demonstrator-focused, HERACLES will concentrate on conceptual design and environmental assessment of hybrid-electric regional aircraft, providing the analytical foundation for future models.
ACI&I
Finally, Airbus is also responsible for ACI&I, or Short Medium Range – Aircraft Configuration Integration and Impact. This project will examine how various new propulsion and airframe technologies integrate in short- to medium-range aircraft, evaluating the performance and environmental impact of different configurations.
What happens next
Although the projects have been selected, their official launch depends on finalising grant agreements, expected by the end of 2025. Work will formally begin in early 2026, with development efforts running into the latter part of the decade.
The most ambitious undertakings, including PHARES, DEMETRA and TAKE OFF, are aiming for flight testing between 2028 and 2029.
The road ahead is steep. Hybrid-electric propulsion introduces complex systems integration and certification questions, hydrogen storage requires entirely new safety standards, and advanced batteries must meet aviation’s uncompromising performance and reliability demands. By pooling public funding, industrial expertise and fresh thinking from smaller players, Clean Aviation hopes to overcome these hurdles.
If the programme delivers on its ambitions, Europe could see the first genuinely climate-friendly regional and short-medium range aircraft entering service by 2035. That would not only bring the sector closer to its net-zero targets but also help secure Europe’s place at the forefront of global aerospace innovation.
