Aircraft development is a protracted process over many years. Novel concept aircraft with new energy sources and disruptive systems technologies are investigated during the aircraft conceptual design phase with the goal to achieve sustainable aviation. Current development cycles need to be accelerated to reduce time to market and development costs of novel aircraft, while still handling complexity and uncertainty of systems technologies. Therefore, a holistic framework for knowledge‐based systems architecting using a model‐based systems engineering approach is presented. This framework has the purpose to conserve and provide knowledge, i.e., information, data, and experiences about existing systems architectures, to the engineer. The developed framework consists of a database concept, a method for model‐based systems architecting, and an interface to the overall systems design software tool GeneSys. Based on evaluating different modeling languages and tools, MathWorks System Composer is selected as most suitable tool for knowledge‐based systems architecting. The developed framework is then demonstrated by conserving and reusing formalized knowledge for the design of a novel hydrogen‐powered concept aircraft. On‐board systems architecture models are saved in a database and automatically recreated reducing development time. The complete graphical representation could not yet be stored in a formalized manner partly reducing the advantage of a clear representation of model‐based systems architecting. However, this did not reduce automatic recreation and evaluation capabilities.