Summary
The Clean Aviation Joint Undertaking (CAJU) is a successful public-private partnership between the European Commission and the European aeronautics industry that is on the way to achieving its environmental performance targets.
The Clean Aviation JU will develop disruptive new aircraft technologies to support the European Green Deal, and climate neutrality by 2050. These technologies will deliver net greenhouse gas (GHG) reductions of no less than 30%, compared to 2020 state-of-the-art. The technological and industrial readiness will allow the deployment of new aircraft incorporating these technologies no later than 2035, enabling 75% of the world’s civil aviation fleet to be replaced by 2050. The aircraft developed will enable net CO2 reductions of up to 90% when combined with the effect of sustainable ‘drop-in’ fuels, or zero CO2 emissions in flight when using hydrogen as energy source.
Clean Aviation’s aeronautics-related research and innovation activities, focusing on breakthrough technology initiatives, will contribute to the global sustainable competitiveness of the European aviation industry. European aviation research and innovation capacity will be strengthened through the partnership, enabling new and ambitious global standards to be set.
Programme Description
The Clean Aviation Partnership’s Strategic Research and Innovation Agenda [SRIA] sets out the way to achieve the overall vision, in terms of timescales and magnitude of impact. This integrated research roadmapincludes the required upstream ‘exploratory’ research that is essential to finding tomorrow’s pathways to mature technologies, ready to be incorporated into further new and disruptive innovations.
The Clean Aviation trajectory defines two clear horizons towards climate neutrality by 2050:
- 2030: demonstrating and introducing low-emissions aircraft concepts exploiting the research results of Clean Aviation, making accelerated use of sustainable fuels and optimised ‘green’ operations, so these innovations can be offered to airlines and operators by 2030 for an entry into service [EIS] in the 2030-2035 timeframe;
- 2050: climate-neutral aviation, by exploiting future technologies matured beyond the Clean Aviation phase coupled with full deployment of sustainable aviation fuels and alternative energy carriers.
The Clean Aviation programme is built on three key thrusts, each with targeted R&I and demonstration efforts driving the energy efficiency and the emissions reduction of future aircraft. Each thrust will develop technologies and enablers, leverage essential knowledge and capabilities, and de-risk the identified technologies and solutions, where further maturation, validation and demonstration is required to maximise impact:
- Hybrid electric regional aircraft
- Ultra-efficient short/short-medium range aircraft
- Disruptive technologies to enable hydrogen-powered aircraft
The implementation of the Clean Aviation work programme is divided into two phases:
- The first phase of the programme (Phase 1: 2022 – 2025) is dedicated to identifying highpotential disruptive aircraft concept(s) by assessing a broad set of potentially relevant configurations. This includes the development and maturation of the contributing technologies and key enablers supported by demonstration and validation to allow a down-selection of most promising technology options and integrated solutions.
- The second phase of the programme (Phase 2: 2026-2031), which will largely depend on the outcome of the first phase, will focus on the most promising aircraft architectures and the integration of the selected best candidate technologies to form aircraft concepts. Key elements of this phase will be large-scale integrated aircraft component/system tests and large-scale flying demonstrator platforms to validate and demonstrate the performance of the key technologies and the targeted aircraft at realistic sizes and operational conditions.
The clean aviation technologies that this programme are developing will enable future aircraft to:
- cut fuel burn & related CO2 emissions by 20-30%
- cut noise levels.
The public – thanks to less noise pollution and lower emissions, better travel options and improved industrial competitiveness in Europe.
The economy – aeronautics is among the EU’s most successful industries. Clean Aviation will help shape a European labour force able to develop the cutting-edge technology necessary to remain on top of the market.
Small & medium-sized businesses – growing numbers of such firms are getting involved through calls for project proposals offered under Clean Aviation. This opens up new opportunities for them and new potential supply chains for established industry players.
Scientific community & academia – Clean Aviation offers ways of speeding up the application of novel technologies. It gives industry and science a chance to jointly address challenges and priorities.
Thematic Categories
- Environment and Climate Change
- Industry
- Other Services
- Other Thematic Category
- Public Administration
- Research, Technological Development and Innovation
- Transport
Eligibility for Participation
- Central Government
- Educational Institutions
- International Organisations
- Large Enterprises
- Legal Entities
- Other Beneficiaries
- Parliamentary Bodies
- Private Bodies
- Researchers/Research Centers/Institutions
- Semi-governmental organisations
- State-owned Enterprises
- Training Centres
Programme Opening Date
Programme Closing Date
EU Contact Point
Clean Aviation Joint Undertaking
Website: https://www.clean-aviation.eu/
Τelephone: +32 2 221 81 52
Fax: +32 2 221 81 50
Address: Clean Aviation Joint Undertaking, White Atrium Building TO56, 1049 Bruxelles/Brussel, Belgium
Programme/Sub-programme/Plan Calls
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Demonstration of advanced FC propulsion techno-bricks for a fully electric hydrogen fuel cell powered aircraft
OpenedCode: 39964 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-HPA-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of the critical components and sub-systems of a hydrogen fuel cell engine for the fully electric hydrogen fuel cell powered aircraft concept. This project will deliver and demonstrate the components and sub-systems on ground at TRL5, for a lightweight, compact and efficient fuel cell engine, demonstrated at TRL4 thus enabling a viable hydrogen fuel cell powered aircraft concept.
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Ground Demonstration of Hybrid-Electric Propulsion Architectures for the Ultra-efficient SMR aircraft
OpenedCode: 39961 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-SMR-03 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of hybrid-electric propulsion architectures for the Ultra-Efficient SMR aircraft. This topic covers the demonstration of hybrid-electric sub-systems integrated into ducted or unducted engines at TRL5 through ground demonstrations with an aim to demonstrate the benefits from such propulsion architectures targeting at least 5% CO2 emissions reduction at aircraft level, with a clear roadmap towards TRL6 by 2030 supporting a future product launch compatible with an EIS by 2035.
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Demonstration of an Ultra-Efficient Rear Fuselage and Empennage and Its Integrated Industrial System enabling EIS2035 for the SMR Aircraft
OpenedCode: 39958 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-SMR-02 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of an Ultra-Efficient Rear Fuselage and Empennage (RFE) and its integrated industrial system for the Ultra-Efficient SMR Aircraft. This topic targets the delivery of a RFE full component assembly alongside an Industrial system including advanced manufacturing and assembly processed supporting the high-rate production of such structural components at TRL6, with an aim to significantly reduce the weight at component level and increase competitiveness through co-development of product and production processes, ensuring a clear route towards certification, exploitation and industrialisation for EIS 2035.
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Demonstration of an Optimized System Platform for Ultra-efficient SMR Aircraft
OpenedCode: 39953 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-SMR-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of an optimized systems platform enabling the next-generation Ultra-Efficient SMR aircraft. The topic aims to integrate high-performance computing, electrical power and data architectures into a unified, certifiable platform, supporting advanced functions such as active control, hybridisation and predictive maintenance by means of a representative ground demonstration at TRL6 validating performance, safety and cybersecurity, with clear pathways to CRL4 and future maturation towards aircraft integration and EIS 2035.
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Demonstration of advanced airframe for ultra-efficient regional aircraft
OpenedCode: 39950 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-REG-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of an advanced airframe, including the wing, fuselage, empennage, and key enabling systems, for the Ultra-Efficient Regional Aircraft concept based on hybrid-electric propulsion. The topic targets a 10% CO2 reduction contribution from airframe technologies compared to 2020 State of the Art, and covers ground demonstrations to TRL6, supporting an entry into service by 2035. See the topic description document published with this call for full details.
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Demonstration and Validation of icing Certification Methodologies compatible with EIS2035 for the SMR and REG Aircraft
OpenedCode: 39947 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-TRA-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Development and demonstration of harmonized icing certification methodologies for Appendix O Supercooled Large Droplet (SLD) Icing conditions. The topic covers validation of numerical prediction tools against representative test results and creation of a means of compliance and regulatory roadmap in close collaboration with EASA and other aviation authorities to support (TRA)t efficient future certification process enhancing aviation safety and ensuring EIS 2035 for the Ultra-Efficient SMR and Regional aircraft. See the topic description document published with this call for full details.
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Hydrogen powered aircraft concepts and key technologies integration and impact assessment
OpenedCode: 39944 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2026-04-ACI-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 31/03/2026 | End submission calls: 19/05/2026
Integration and performance assessment of the fully electric hydrogen fuel cell powered aircraft and the direct hydrogen combustion propulsion aircraft concepts introduced in the CAJU SRIA. The topic covers the integration and co-ordination of CAJU key technology projects into a comprehensive aircraft concept at TRL4, demonstrating the viability of the aircraft concept and delivering a performance, emissions and maturity assessment.
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Aircraft concept and key technologies integration and impact assessment
ClosedCode: 36235 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-ACI-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The second phase of Clean Aviation (2026-2030) will concentrate on integration and demonstration of technologies into aircraft concepts powered either by Sustainable Aviation fuel (SAF), as a single source of energy, or combined with electric hybridisation.
From the four aircraft concepts proposed as part of Clean Aviation SRIA, this topic shall focus on the following aircraft configurations:
- An ultra efficient short and medium range concept with 200-250 pax capacity and a design range up to 3000NM.
- An ultra-efficient regional concept with 50-100 pax capacity with a design range up to 500NM.
The proposals shall explore the most promising routes around various aircraft concepts and critical technologies having the potential to reduce CO2 emissions by no less than 30%.
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Ground Test Demonstration up to TRL5 of On-Board NPE Systems Architecture for SMR Aircraft
ClosedCode: 36230 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-SMR-03 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The SMR aircraft concept proposed in Clean Aviation is expected to be a tube and wing configuration, with a 2035 EIS target. Such an aircraft concept should have a capacity of around 200-250 pax with a design range up to 3000NM, operated on a typical mission of 800NM at cruise speed Ma 0.78.
This topic is intended to deliver an integrated and validated electrical energy provision sub-system, by project completion at TRL5, maturing the equipment up to a representative level of its functioning on the electric network, supported by critical technology bricks being representatives of the main loads such as electric engine start, eECS, Air supply and cabin heating, eIPS and Electric Actuation matured to TRL5.
The scope of the topic is to design, develop, demonstrate, and deliver an SMR system architecture and components for an on ground demonstration up to TRL5.
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Demonstration of On-board Systems relevant for hybridisation of Regional aircraft
ClosedCode: 36228 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-REG-02 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The present topic aims to develop and demonstrate the on-board system technologies needed for hybrid-electric propulsion and more-electric non-propulsive systems in-flight demonstration, with an electrical propulsive power of up to 1MW per side and a minimum electrical power of 100kW for all electric non-propulsive consumers. The selection of the hybridisation ratio shall be compatible with the performance targets at aircraft level. Those systems are key enablers for the ultra-efficient regional aircraft concept.
The project scope is therefore to design, demonstrate, and deliver the integrated on-board systems architecture and components for a full-scale in-flight demonstration of hybrid-electric propulsion.
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Demonstration of a Hybrid-Electric Propulsion System for Regional aircraft, including Pylon and Nacelle Integration and modification
ClosedCode: 36226 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-REG-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The present topic aims to develop and demonstrate the hybrid-electric propulsion system needed for in-flight demonstration, delivering a total power of about 2 to 3MW (per side), with an electrical propulsive power of up to 1MW (per side). The selection of the electrical power and hybridisation ratio shall be compatible with the performance targets at aircraft level. Those systems are key enablers for the ultra-efficient regional aircraft concept.
The project scope is therefore to design, demonstrate, and deliver the fully integrated hybrid-electric propulsion system needed for a full-scale in fight demonstration.
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Flight Test Demonstration of an Unducted Engine Architecture for SMR Aircraft
ClosedCode: 36221 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-SMR-02 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
This topic is intended to deliver an ultra-efficient unducted engine architecture installed on aircraft expected to meet, by project completion, an unducted propulsion system architecture at TRL6, to be flight tested in real operating conditions as a validation for the propulsion architecture.
The overall scope of the topic stems from the aim of validating an SMR unducted engine architecture demonstrator in flight test at TRL6 to demonstrate the expected CO2 emissions reduction at aircraft level. The engine activities include the whole propulsion system, for example, including the multifunctional cowls
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Ground Test Demonstration and Preparation of Flight Test of an Ultra High Bypass Ratio Ducted Geared Turbofan Engine for SMR Aircraft
ClosedCode: 36219 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-SMR-01 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The SMR aircraft concept proposed in Clean Aviation is based on a tube and wing configuration, with a 2035 EIS target. This topic is intended to deliver a full ultra-efficient engine ground demonstrator to meet, by project completion, a propulsion system at TRL5, supported by critical technology bricks, to be flight tested in real operating conditions at a later stage in the programme. Applicants should propose and build a demonstration plan aiming to validate a propulsion architecture on ground by end of 2029 and subsequently in flight by end of 2030.
The primary objective of the topic, is to design, develop, manufacture, and test an UltraHigh Bypass Ratio ducted engine for SMR aircraft for ground testing up to TRL5, including advanced core engine and combustion technologies, advanced thermodynamic (variable) cycle and hybridisation.
The second objective of the topic is to prepare the fully instrumented and modified Flight Demonstration Platform to enable the flight test of the Ultra-High Bypass Ratio ducted turbofan architecture for SMR aircraft, at a later stage in the programme, to validate the technologies at TRL5. -
Flight Test Demonstration of Hybrid-Electric Propulsion for Regional aircraft
ClosedCode: 36217 | Identifier Code: HORIZON-JU-CLEAN-AVIATION-2025-03-REG-03 | Programme name: Clean Aviation Joint Undertaking (CAJU) | Start submission calls: 27/03/2025 | End submission calls: 15/05/2025
The present topic aims to develop and demonstrate in-flight the aircraft integration of an hybridelectric powertrain delivering a total power of about 2 to 3MW (per side), with an electrical propulsive power of up to 1MW (per side). The selection of the electrical power and hybridization ratio shall be compatible with the performance targets at aircraft level. This in-flight demonstration is a key enabler for the ultra-efficient regional aircraft concept.
The project scope is therefore to design and integrate a hybrid-electric aircraft Flight Test Demonstrator, and perform the ground and flight test demonstrations at full scale.