Third-Party Risk Analysis of Small Unmanned Aircraft Systems Operations

Abstract

Small unmanned aircraft systems (sUASs) are widely used in various applications, and their traffic will increase as the field of operations becomes varied. Increased traffic will potentially involve a higher possibility of conflicts between sUASs, and midair collisions can occur when the risk of conflicts is not fully mitigated by detect-and-avoid capabilities. Therefore, third-party risk should be assessed, especially for urban airspace. This paper proposes a methodology for the assessment of third-party risk due to midair collisions between sUASs. As a worst-case scenario of sUAS operations in urban airspace, this paper uses the proposed model to analyze the third-party risk in a central business district in a metropolitan city. The results show that third-party risk is not acceptable for the given traffic scenario. Based on these results, several methods are suggested to reduce the third-party risk and satisfy the target level of safety. In addition, the results shown in this paper can be used as references for certificates of operation and/or mitigation devices for sUASs. The main contribution of this paper is to build a third-party risk model that takes into account midair collisions between sUASs and the energy loss during impact.