Formal Approach to Safety‐Driven Dynamic Procedure Modeling

ABSTRACT Ensuring the safety of unmanned aerial systems (UAS) is a growing concern as the number of UAS grows increasingly fast. Regulatory bodies are in the process of tackling this problem by issuing standards and recommendations to be met by UAS designers. The European Union Aviation Safety Agency (EASA) published the Specific Operations Risk Assessment (SORA). Among others, it requires that procedures are appropriately defined and designed. Currently, procedures are still widely found in the form of text‐based documents, making them difficult to analyze for safety. This makes it difficult for UAS designers to validate their procedures and acquire flight authorizations from the relevant authorities. In this article, our aim is to facilitate this process. To that end, we expand on our previous work on modeling procedures. We propose a clearly delineated methodology for modeling UAS flight procedures. We perform analyses that reveal more complex failure scenarios than we could previously identify. We illustrate this on a relevant fixed‐wing UAS for which we model, simulate, and analyze three emergency flight procedures.