Model-based analysis and validation using simulation is a helpful tool in the engineering of complex systems. This paper presents a tool chain for the model-based architectural design of avionic fiber-optic networks. A recently proposed framework for simulation-based domain-specific tools is the basis for the development. It supports a model-based design workflow and offers a new 3D graphical user interface for location-based configuration and result visualization of the underlying simulation tool. The benefits of the tool are validated with an application example, in which different topologies for avionic fiber-optical networks are evaluated and compared.