The thesis presented explores the retrofit design of an aircraft to integrate a crashworthy hydrogen storage system, with a specific focus on enhancing aviation sustainability by utilizing hydrogen as a zero-emission fuel. By aligning with global decarbonization goals, the study addresses the advancements and challenges in hydrogen storage technologies, particularly centering on cryogenic liquid hydrogen. The design process involves the development and analysis of both single-wall and double-wall tank architectures to assess their performance, considering aspects such as cruise time and dormancy time. A key aspect of the research is the detailed examination of the inner vessel support structure within a double-wall cryogenic tank. This examination highlights the crucial role of the support structure in maintaining structural integrity, accommodating thermal expansion and contraction, and minimizing heat transfer while operating within the space constraints of an aircraft. Additionally, simulations and sensitivity analyses are employed to evaluate the proposed designs, offering valuable insights into the feasibility and effectiveness of implementing hydrogen storage solutions within existing aircraft structures. Dr. Ing. S.G.P. Castro supervised the thesis, emphasizing the importance of advancing aviation sustainability through innovative retrofit designs that incorporate crashworthy hydrogen storage systems.