Evaluating ISO 21448 (SOTIF) Principles for Aviation System Safety

In the automotive industry, Safety of the Intended Function (SOTIF, ISO 21448) is a framework to reduce unknown hazard scenarios in the operational design domain and mitigate known hazard scenarios to achieve acceptably safe system behavior. Civil aviation practices, such as ARP4754B and ARP4761A, have a similar intent. A review of ISO 21448 from an aerospace perspective will identify potential opportunities to leverage SOTIF principles to complement the above aerospace recommended practices, as well as potential conflicts between these approaches. One key aspect is the proactive identification of safety requirements and potential architectural deficiencies early in the development process. This can be especially valuable when introducing new functionalities such as autonomy where system boundaries go beyond traditional architectures, and where identifying unforeseen situations that impact safety becomes particularly challenging. The paper will identify opportunities and limitations in the application of SOTIF within the aerospace industry to address such challenges and develop systems that are inherently safer and more robust throughout the operational lifecycle.