Periodic Reporting for period 3 - AMBER (InnovAtive DeMonstrator for hyBrid-Electric Regional Application)
Reporting period: 2024-07-01 to 2025-06-30
AMBER is a demonstrator which aims to mature, integrate and validate key technologies necessary for a megawatt-class hybrid electric propulsion system ( . 2MW) powered by hydrogen fuel cells. The project, in the frame of Clean Aviation, will study integration of hybrid electric components - including a motor/generator, power converters, power transmission systems – with fuel cells for rig testing in the mid-2020s, using Avio Aero’s advanced Catalyst turboprop engine; the architecture envisioned is a parallel hybrid configuration.
The project is part of the Avio Aero and GE Aerospace portfolio of suitable technologies for a more sustainable future of flight.
The target is to support the SRIA objectives and to significantly reduce CO2 emission by at least 30 % at EIS compared to 2020 state of the-art regional aircraft. AMBER recognises the importance of regional aviation as stepping stone to mature hybrid technologies leading the way towards sustainability and achieving ambitious environmental goals.
The project is part of the Avio Aero and GE Aerospace portfolio of suitable technologies for a more sustainable future of flight.
The target is to support the SRIA objectives and to significantly reduce CO2 emission by at least 30 % at EIS compared to 2020 state of the-art regional aircraft. AMBER recognises the importance of regional aviation as stepping stone to mature hybrid technologies leading the way towards sustainability and achieving ambitious environmental goals.
The project was successfully kicked off in January 2023 with a two-day meeting in Turin, attended by 21 partners and the Clean Aviation Joint Undertaking (CAJU). This meeting set the stage for presenting the project’s ambitions, alignment with European targets, and the demonstration strategy focused on several rig tests in the first phase of Clean Aviation.
At the project start, there was a focus on team establishment and ramping up resources. The team concentrated on critical tasks and requirements definition at the propulsion system level, enabling flow-down to sub-system and component levels. Trade-off and design studies for key components, such as the thermal management system, power gearbox, control system, electrical drive, and fuel cell system, were initiated. Interface specifications between modules were also developed. The main achievements can be summarized as follows:
- At Propulsion System level, the Conceptual Design Reviews (CDRs) for the thermal management system, fuel cell system, and combining gearbox have been finalized. Models to simulate propulsion system behaviour for the different disciplines such as performance, structures and dynamics, 3D integrated geometry, have been created and are supporting the design of the propulsion system. Additionally, some tests on additively manufactured coupons heat exchangers, part of the thermal management system have been completed allowing preliminary characterization of the components. The programme is moving towards Preliminary Design Review (PDR).
- Related to the thermal engine work package, the Conceptual Design Review (CDR) for the gas turbine has been finalized, allowing to start the activities for the next design review phase. Combining power gearbox has already achieved Preliminary Design Review (PDR), enabling the launch of LLTI (Long Lead Time Items) manufacturing process.
- The electrical drive, power distribution system and fuel cell system are approaching the preliminary design stage, with preliminary design reviews to follow. Testing of the DC-DC converter and EPDU modules is on track for 2025. Additionally, progress has been made in the electromagnetic, mechanical, and thermal design of the FHG electric machine, as well as increasing the maturity level of simulation models & CAD for the power electronic modules and the overall electrical & control system. The trade-off analysis of fault detection algorithms has been completed.
Furthermore, the FC-System test at DLR BALIS is undergoing detailed preparation, as well as the integrated power electronics and power emulation test at FHG IISB. Several technical reviews have been completed, in order to de-risk and ensure the functionality of the design for the test enabling modules, HV-network, control architecture and CONOPS of these key tests for the validation of the Electrical Power Flow.
For Fuel Cell System the Preliminary System Safety Assessment has been executed, and the Interface Control Document (ICD) has been updated to include all physical interface definitions. Interface definitions relevant to demonstration activities have been prepared. The fuel cell system architecture has been updated based on Functional Hazard analyses and safety assessments.
A comprehensive Concept Design Review for the HV electrical system has been performed to baseline the requirements set and all architecture concepts. This will now be used to prepare the detailed test architectures and test objective to enable the system level requirement validation.
- AMBER demo will have 3 main rig testing to prepare for the overall integration of the Propulsion System Demo: the mechanical power flow, the electrical power flow and the control system testing. Main results related to this activity is that high-level test goals and requirements for all key ground demonstrations have been captured. A detailed and integrated time plan for hardware delivery, software release, facilities preparation, and test execution has been defined. Additionally, main facilities modifications have been identified, and ICD documentation has been initiated. Modifications to the test facility have been defined, as well testing requirements of the electrical drive line and fuel cells has been defined, the test will be performed in Balis, DLR test facility. Recently (May 2025) the fuel cell system demonstrator has been completed as well as its successful integration into the BALIS test facility.
-Since the beginning of the project, Avio Aero has successfully collaborated with EASA to align on the certification impact of the new configuration. The main current result is the delivery of a preliminary impact assessment on certification and the advancement of the certification GAP analysis. Additionally, collaboration with the airframer and other Clean Aviation projects has ensured continuous coordination for integration at the aircraft level, aligning with high-level Clean Aviation goals. The main goal is the evaluation of AMBER integration on new UERA concept, measured through quantitative analysis, and highlight eventual technical gaps.
At the project start, there was a focus on team establishment and ramping up resources. The team concentrated on critical tasks and requirements definition at the propulsion system level, enabling flow-down to sub-system and component levels. Trade-off and design studies for key components, such as the thermal management system, power gearbox, control system, electrical drive, and fuel cell system, were initiated. Interface specifications between modules were also developed. The main achievements can be summarized as follows:
- At Propulsion System level, the Conceptual Design Reviews (CDRs) for the thermal management system, fuel cell system, and combining gearbox have been finalized. Models to simulate propulsion system behaviour for the different disciplines such as performance, structures and dynamics, 3D integrated geometry, have been created and are supporting the design of the propulsion system. Additionally, some tests on additively manufactured coupons heat exchangers, part of the thermal management system have been completed allowing preliminary characterization of the components. The programme is moving towards Preliminary Design Review (PDR).
- Related to the thermal engine work package, the Conceptual Design Review (CDR) for the gas turbine has been finalized, allowing to start the activities for the next design review phase. Combining power gearbox has already achieved Preliminary Design Review (PDR), enabling the launch of LLTI (Long Lead Time Items) manufacturing process.
- The electrical drive, power distribution system and fuel cell system are approaching the preliminary design stage, with preliminary design reviews to follow. Testing of the DC-DC converter and EPDU modules is on track for 2025. Additionally, progress has been made in the electromagnetic, mechanical, and thermal design of the FHG electric machine, as well as increasing the maturity level of simulation models & CAD for the power electronic modules and the overall electrical & control system. The trade-off analysis of fault detection algorithms has been completed.
Furthermore, the FC-System test at DLR BALIS is undergoing detailed preparation, as well as the integrated power electronics and power emulation test at FHG IISB. Several technical reviews have been completed, in order to de-risk and ensure the functionality of the design for the test enabling modules, HV-network, control architecture and CONOPS of these key tests for the validation of the Electrical Power Flow.
For Fuel Cell System the Preliminary System Safety Assessment has been executed, and the Interface Control Document (ICD) has been updated to include all physical interface definitions. Interface definitions relevant to demonstration activities have been prepared. The fuel cell system architecture has been updated based on Functional Hazard analyses and safety assessments.
A comprehensive Concept Design Review for the HV electrical system has been performed to baseline the requirements set and all architecture concepts. This will now be used to prepare the detailed test architectures and test objective to enable the system level requirement validation.
- AMBER demo will have 3 main rig testing to prepare for the overall integration of the Propulsion System Demo: the mechanical power flow, the electrical power flow and the control system testing. Main results related to this activity is that high-level test goals and requirements for all key ground demonstrations have been captured. A detailed and integrated time plan for hardware delivery, software release, facilities preparation, and test execution has been defined. Additionally, main facilities modifications have been identified, and ICD documentation has been initiated. Modifications to the test facility have been defined, as well testing requirements of the electrical drive line and fuel cells has been defined, the test will be performed in Balis, DLR test facility. Recently (May 2025) the fuel cell system demonstrator has been completed as well as its successful integration into the BALIS test facility.
-Since the beginning of the project, Avio Aero has successfully collaborated with EASA to align on the certification impact of the new configuration. The main current result is the delivery of a preliminary impact assessment on certification and the advancement of the certification GAP analysis. Additionally, collaboration with the airframer and other Clean Aviation projects has ensured continuous coordination for integration at the aircraft level, aligning with high-level Clean Aviation goals. The main goal is the evaluation of AMBER integration on new UERA concept, measured through quantitative analysis, and highlight eventual technical gaps.
The development of a hybrid-electric propulsion system for regional aircraft, with at least 50% hybridization, represents this very challenging, yet achievable intermediate step and can allow for a mission fuel burn reduction by at least 30% compared to 2020 state-of-the-art regional aircraft. A thermal engine that allows the use of 100% sustainable aviation fuel, will also be able to reduce lifecycle GHG emissions by up to 80%. The proposed project AMBER (innovAtive deMonstrator for hyBrid-Electric Regional application) addresses this aspect and pursues the maturation of hybrid-electric key components of a product-representative parallel hybrid-electric propulsion system architecture, fuel cell based, for next-generation regional aircraft with EIS by 2035+, to meet the ambitious environmental goals set out in SRIA and the Clean Aviation topic call.