Developing a Liquid Hydrogen (LH2) System Layout for an Aircraft: A Programmer's Perspective

Abstract: The future of aviation lies in the adoption of sustainable technologies such as liquid hydrogen (LH2) fuel systems. The integration of these systems requires sophisticated management of the fuel flow, control mechanisms, and pilot interaction. This paper discusses the development of an LH2 system layout for a next-generation aircraft, with a focus on the simulation and interface design process from a programmer’s perspective. Utilising Cranfield University’s Future Systems Simulator (FSS), an iterative design and implementation process involved collaboration between pilots, engineers, and human factors specialists. Design and implementation: Initial conceptual designs were created in Miro during a series of workshops with subject-matter experts and pilots that refined key control elements and safety-critical aspects of the LH2 system. These prototypes were implemented in the FSS using Unity and linked with the aircraft and engine models, providing a platform for instant changes based on the pilot's feedback. Key technical challenges included developing control-loop algorithms for HMI that allowed autonomous engine management with pilot override capabilities. Data transmission between the FSS and LH extsubscript{2} model was optimised using half-byte encoding to handle real-time system data efficiently despite the large volume of information. Scenario: A series of test flights were performed in the FSS using the newly developed LH2 engine model and HMI layout. The first test was a "clean" flight, with no system faults, where pilots started the LH2 engines using electronic checklists, completed a circuit flight, and landed. Subsequent flights involved triggering system faults to assess pilot responses. Two sessions were conducted: the first with project-involved pilots aware of the potential faults, and a second "blind" trial with external pilots. Pilots wore eye-tracking devices, and post-flight interviews were conducted to gather qualitative feedback. System Usability Scale (SUS) scores were also recorded to evaluate interface usability.The pilot interface provided intuitive synoptic pages for system monitoring and control to enhance situational awareness and response times. Feedback from the trials will guide future refinements to the HMI layout, focusing on safety and usability optimisation.Conclusions: This paper demonstrates the integration of advanced programming techniques and human-centred HMI design, which is critical to the successful implementation of sustainable fuel technologies in aviation. It also highlights the importance of flight simulation platforms like the FSS in enabling safe and cost-effective development and testing of these systems. Future research will focus on optimising the procedures, layout design, and control algorithms, which will lead to conducting real-world validation tests for certification.

Keywords: Liquid Hydrogen, Flight Deck Design, Human-Computer Interactions, System Usability

DOI: 10.54941/ahfe1005864

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