A New Approach to Hazard Analysis for Rotorcraft

STPA is a new hazard analysis technique that can identify more hazard causes than traditional techniques. It is based on the assumption that accidents result from unsafe control rather than component failures. To demonstrate and evaluate STPA for its application to rotorcraft, it was used to analyze the UH-60MU Warning, Caution, and Advisory (WCA) system associated with the electrical and fly-by-wire flight control system (FCS). STPA results were compared with an independently conducted hazard analysis of the UH-60MU using traditional safety processes described in SAE ARP 4761 and MIL-STD-882E. STPA found the same hazard causes as the traditional techniques and also identified things not found using traditional methods, including design flaws, human behavior, and component integration and interactions. The analysis includes organizational and physical components of systems and can be used to design safety into the system from the beginning of development while being compliant with MIL-STD-882.