The article presents a concept of an automatic directional control system for a General Aviation class aircraft during the taxiing phase. In particular, it shows the concept of the system and the control laws synthesis – mathematical model and simulation of taxiing aircraft. Several reasons have emerged in recent years that make the automation of taxiing an important design challenge including decreased safety, performance and pilot workload. The adapted methodology follows the model based design approach in which the control system and the aircraft are mathematically modelled to allow control laws synthesis using the Adaptive Disturbance Rejection Control method. The computer simulations are carried out to analyze the control system behavior. Chosen methodology and modelling technique, especially tire-ground contact model, resulted in a taxing aircraft model that can be used for directional control law synthesis. Aerodynamic forces and moments were identified in the wind tunnel tests for the full range of the slip angle. The results can be used for the preliminary performance assessment of the ADRC method applied in the taxi directional control system. Such system has not been introduced to General Aviation yet. Therefore, the model of taxiing aircraft including aerodynamic characteristics for the full range of the slip angle and a directional control system have a big value in the process of design and implementation of the future automatic taxi systems.