Incorporating Model Based Safety Design into Development Process of Civil Aircraft Systems

The traditional ARP 4761 based safety assessment in development process of civil aircraft systems focuses on safety evaluation of system architecture, which provides few guidance in safety design against system operation hazards. It is difficult for an inexperienced engineer to give valuable suggestions for architecture improvement, and more difficult to translate the safety assessment results into specific safety design requirements. The model-based safety-guided design method based on STPA is incorporated into civil aircraft system development process in this paper, in that case, the safety thinking is included in the early system design in order to capture safety design requirements and reduce the cost introduced by later assessment iterations. The paper illustrates the new method with a case that includes typical real-world civil aircraft system “command and monitor” architecture, this application of the proposed method will be a verification of the method validity.