Conceptual Modeling of Risk Interactions for Flight Crew Errors in Unmanned Aerial System Operation.

As revealed by the mishap causal factor statistics, flight crew error was the most critical factor to affect the safe operation of large Unmanned Aerial System (UAS). However, most research on this topic embedded their roots on event-chain based accident model or even relied on textual descriptions to discuss the risk mechanism leading to large UAS mishaps. It is hard for preventing future losses of UASs in a systemic and efficient way, especially consider the organizational context of flight crew error shaping factors. Based on the System Dynamics approach, this study proposed to illustrate the risk mechanisms that involve the interactions of organizational, flight crew and technical system factors leading to operation accident of large UASs. It aims to explain such risk interactions and helps to clarify why flight crew training always gained a delayed safety benefits on crew error reduction, especially when UAS fleet facing high mission tempos. This study also discusses the effect of flight crew self re-learning process and safety commitments on UAS operation accidents. Some Causal Loop Diagram (CLD) based conceptual models are established for future quantitative SD stock-flow simulation which can be used as organizational risk assessment tools, when considering to evaluate the medium-long term benefits of potential safety policy and management decision in the widely spreading UAS operations.