The article presents theoretical foundations of designing the components of an aircraft onboard cable network, proposed as a methodology for solving the problems of designing onboard equipment. The composition of the initial and developed technical documentation for the aircraft onboard cable network is determined. The article also shows the relationship between the stages of designing the onboard cable network and the stages of designing the aircraft. The formulation of the general task of creating the components of an onboard cable network is presented as a number of particular subtasks of a lower level of complexity. The method for solving the problem is based on a number of transformations performed with the original documentation in order to develop technical documentation for the introduction of the onboard system into the complex of onboard equipment. A number of successive transformations of the proposed bundle model using the apparatus of topology and multiset theory made it possible to form a model of the components of the onboard cable network of an aircraft that gives a detailed view of its future design. The proposed scientific approach to the design of aircraft onboard cable network components created the prerequisites for minimizing the heuristic component in the process of designing aircraft onboard cable network components.