Applications Open for Third Clean Aviation Joint Undertaking (CAJU) Calls for Proposals

A total of nine Call Topics have launched under the Clean Aviation Joint Undertaking, an institutionalised European Partnership dedicated to developing disruptive new aircraft technologies to transform aviation towards a climate neutral future.

The Clean Aviation Joint Undertaking (CAJU) is an institutionalised European partnership – also known as a Joint Undertaking – established under the Horizon Europe programme (2021-2027). It is the EU’s leading research and innovation programme for transforming aviation towards a sustainable and climate neutral future.

CAJU is built on three coordinated technology development and demonstration areas – known as ‘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:

  • Disruptive technologies to enable hydrogen-powered aircraft (HPA)
  • Hybrid electric regional aircraft (HER)
  • Ultra-efficient short and short-medium range aircraft (SMR)

Participation in the programme is based on proposals submitted to open, competitive calls through the Commission’s Funding & Tenders Portal. These calls are open to members as well as non-members. The following nine Topics are now open for applications. The topics divided under their respective thrusts are as follows:


  • Hydrogen Fuel System for Direct Burn Engine Ground Test Execution and Flight Test Preparation – HORIZON-JU-CLEAN-AVIATION-2023-02-HPA-01: Total budget: €20 million
  • Aircraft Liquid Hydrogen Fuel Distribution System Technologies for Direct Burn Applications – HORIZON-JU-CLEAN-AVIATION-2023-02-HPA-02: Total budget: €10 million
  • Multi-MW Fuel Cell Propulsion System for Hydrogen-Powered Aircraft – HORIZON-JU-CLEAN-AVIATION-2023-02-HPA-03: Total budget: €35 million


  • Innovative Fuselage/Empennage Design for Hybrid-Electric Regional Aircraft – HORIZON-JU-CLEAN-AVIATION-2023-02-HER-01: Total budget: €25 million
  • Open Digital Platform for Hybrid-Electric Regional Aircraft Design – HORIZON-JU-CLEAN-AVIATION-2023-02-HER-02: Total budget: €7 million


  • High-TRL Flight Demonstration Means for Ultra Efficient Propulsion Systems for Short and Short-Medium Range Aircraft – HORIZON-JU-CLEAN-AVIATION-2023-02-SMR-01: Total budget: €20 million
  • Ultra Performance Wing Technologies and Integration for Short and Short-Medium Range Aircraft – HORIZON-JU-CLEAN-AVIATION-2023-02-SMR-02: Total budget: €13 million
  • Advanced Cabin and Cabin Systems Integration for Short Range and Short-Medium Range for Hydrogen-Powered Aircraft – HORIZON-JU-CLEAN-AVIATION-2023-02-SMR-03: Total budget: €7 million

Coordination and Support Actions

  • Aviation Climate and Technology Impact Monitoring Methodology – HORIZON-JU-CLEAN-AVIATION-2023-02-CSA-01: Total budget: €750,000

Any legal entity established in EU Member States and Associated Countries is eligible to apply to open calls, including European companies, universities, research institutes and others.

Unless otherwise provided for in the CAJU Work Programme and the specific topic conditions, legal entities forming a consortium are eligible to participate in actions provided that the consortium includes at least one independent legal entity established in a Member State, and at least two other independent legal entities, each established in different Member States or Associated Countries.

Applications should be submitted by the 11 May 2023 (17:00 Brussels time) deadline.