To enable a technologically and economically feasible H2-powered aviation, new integral LH2 tank solutions are required that could serve as part of the airframe main structure and capable of withstanding its respective loads. The H2ELIOS project will develop an innovative and effective lightweight LH2 storage system for aircraft. It will be implemented as demonstrators in two fuselage-like cylinder section with approximately 1.9 m of external diameter and approximately 2.3 m of external length. These demonstrators would be duly supported by component and subsystem ground tests at appropriate scale at project completion (TRL 5 at storage level). The aim is that the concept is ready to be embedded and integrated in a specified aircraft architecture for flight demonstration in later stages. H2ELIOS will provide a feasible and novel low-pressure double-layer composite tank-based system, enabling the tank shape to be either conformal or non-conformal to the profile of the aircraft. Its general effectiveness will be assessed in terms of high GI performance and easiness of integration within the aircraft structure. This concept will be supported by latest evolutions of innovative methods and technologies in terms of multidisciplinary design development, manufacturing processes and means of compliance and shall be demonstrated in operational conditions: first on ground up to TRL5 and then in flight by the end of Clean Aviation Phase 2 clearing a TRL6 maturation gate. Finally, delivery to the market is expected in the 2030-2035 period. In this way this project shall contribute to accomplish the objectives of the European Green Deal regarding decarbonization of the aviation industry. The activities of H2ELIOS will be supported by explicit agreed support of EASA and an External Advisory Board comprising commercial aircraft OEMs, H2 management and cryogenics experts, MRO services, airlines, aircraft system integrators, materials developers and suppliers and airports operation

The Engines ITD will work towards radical engine architectures and new engine technologies to power the aircraft of the future. The objective is to increase fuel and energy efficiency of the engine and reduce environmental impact, regardless of whether the engine is powering a large airliner or just a small utility aircraft, meaning more thrust while burning less fuel and emitting less CO2, NOx and noise.

Encounters with atmospheric turbulence are a vitally important in the design and certification of many manmade structures such as aircraft and wind turbines. Gusts cause rapid changes in the flow about the structures which leads to rigid and flexible unsteady responses. Knowledge of aircraft/gust interactions is therefore vital for loads estimation during aircraft design as it impacts on control systems and often defines the maximum loads that these structures will experience in service. At present industry typically uses the linear doublet lattice method with static loads corrections from expensive wind tunnel data. The wind tunnel data is created using the final aerodynamic surface in the predicted cruise shape. This means that gust loads come relatively late when the design options have been narrowed. Increased competition and environmental concerns are likely to lead to the adoption of more flexible materials and the consideration of novel configurations, in which case the linear assumptions of the current gust loads process will become unacceptable. To introduce non-linearity into the gust loads process without significantly increasing the cost and time, this project has three main objectives: to carry out investigations using CFD so that the non-linearities in gust interactions are understood; to create a gust loads process that does not require wind tunnel data and hence reduces the need for wind tunnel testing; to develop updated reduced order models for gust prediction that account for non-linearity at an acceptable cost. These investigations will reduce the need for expensive wind tunnel testing and hence lead to time and cost savings at the design stage therefore ensuring that the European aerospace and defence industry remain competitive in the future. The wind turbine industry has similar concerns, with gusts and wind shear restricting the locations available for wind farms. The project will also address these issues using common methodology.

ALRIGH2T responds in full to the expected outcomes and scope of the HORIZON-CL5-2023-D5-01-07 topic, by developing and demonstrating two alternative technologies for LH2 aircraft refuelling: - Direct LH2 refuelling, encompassing the definition of operational protocols for safe and rapid refuelling, the development and testing of a LH2 transfer pump and an instrumented tank, their integration in an iron bird laboratory for the execution of refuelling/defueling tests and the delivering of a digital twin model. - LH2 tanks swap refuelling, encompassing end-to-end logistic and supply chain of tank modules, the design of the associated on- and off-site infrastructure and its demonstration. Both concepts will achieve TRL 6 by the end of the project, undergoing a comprehensive technology evaluation informed by demonstration results in two major airports, i.e. Milan Malpensa and Paris (Orly or LeBourget) respectively. The two technology lines are complemented by transversal activities for the definition of technical and techno-economic boundary conditions, the demonstration of the use of H2 for ground operations (i.e. H2 powered tow vehicle, demonstrated at the Malpensa site) as well as environmental, safety and regulatory cross-cutting aspects. ALRIGH2T has the ambition of demonstrating, for the first time, LH2 refuelling in a scale compatible with airport operations, synergizing with the Clean Aviation research and development efforts at the aircraft level. The project is implemented by a consortium built on the competences of top European industrial players, positioned along entire hydrogen and aeronautic value chain, complemented by research and technology organisations and selected member of the Advisory Board, including the EASA. ALRIGH2T is expected to be a cornerstone in the path towards the deployment of LH2 as an aviation fuel, strengthening the European research and industry leadership and consolidating the role of green airports as hubs of the H2 economy

The Airframe ITD aims at re-thinking and developing the technologies as building blocks and the “solution space” on the level of the entire or holistic aircraft: pushing aerodynamics across new frontiers, combining and integrating new materials and structural techniques – and integrating innovative new controls and propulsion architectures with the airframe; and optimizing this against the challenges of weight, cost, life-cycle impact and durability.