The project successfully completed its first annual review in November 2024, followed by a confirmation of good progress at the intermediate review meeting in May 2025. Subsequently, an amendment process was undertaken to align the project with the adapted ZEROe roadmap.
In terms of concept development the detailed design of a 4-engine aircraft configuration advanced, including an optimized 2-bar cryogenic LH2 tank and a slotted-flap high-lift system. Current efforts focus on optimizing cooling duct geometries to overcome challenges in internal heat exchanger integration impacting aerodynamic efficiency.
Regarding the storage and distribution system, functional testing of the prototype tank validated the performance with liquid hydrogen under static and dynamic roll/pitch scenarios. This success underpinned the final design release and manufacturing launch of the ground demonstration tank.
Simultaneously, the air systems line design for the ground demonstrator is finalized, incorporating modifications to existing hardware, a new structural frame, and test cell adjustments.Motor Control Units (MCUs) have been manufactured, tested, and delivered, and commissioning has begun. Adsorbent materials for filtration were characterized to support the system-level model. Future concept optimization validated a multi-point turbo-compressor design.
The fuel cell system architecture is frozen, enabling the beginning of the module assembly and simulation refinement. Fuel cell stack testing is progressing. Balance of Plant validation continues. Control software development moved to a Model-in-the-Loop environment for pre-calibrating operating strategies against the updated plant model.
Cooling line definition and requirements for equipment, hardware, and software were completed. Cooling line component manufacturing finished following successful electrical commissioning and interface testing. Key units (e.g. valves) were delivered for demonstrator integration after final acceptance. Additional units are being prepared for design verification and qualification.
Progress also extends to the power line, where the ground demonstrator hardware advanced through propeller gearbox functional testing and eMotor MCU verification activities. In addition, multi-physics modeling studies were conducted to identify the optimal efficiency-mass trade-off for a future eMotor.
These collective efforts culminated in the finalization and freezing of the full ground demonstrator detailed design. Functional interfaces are defined. The high-level test sequence is established and the installation of the test bench infrastructure is advancing.
To ensure future scalability, a technical gap analysis was initiated by establishing a methodological framework and defining key performance indicators. The first critical components for scalability were identified, and the development of a propulsion system simulation model began to support these assessments.
Finally, Communication and Dissemination activities have enhanced project visibility through the launch of a LinkedIn channel and streamlined internal approval processes. The consortium has achieved significant dissemination goals, presenting at major aerospace conferences and publishing multiple peer-reviewed articles.
