Model-Based Safety Analysis Methodology for Civil Aircraft Flight Control System

Traditionally, safety analysis of the civil aircraft Flight Control System (FCS) is depend on the understanding of system behavior by analysts. The maturity and credibility of the analysis results are limited by the cognitive level of analysts. In addition, the synchronicity of system design process and safety assessment process is lower, as well as the lack of synergy among different analyst's analysis results. To solve these issues, a model-based safety analysis method for civil aircraft flight control systems is proposed. Firstly, an physical architecture model is established to describe the behaviors of the civil aircraft flight control system. Based on this model, the safety attributes of the model elements are defined. Then, the definition and connection of the system failure states from input to output are completed based on fault propagation logic. Finally, fault tree analysis of the pitch control failure condition of the flight control system is conducted, and the evaluation results validate the effectiveness of the proposed safety assessment method.