Categorization of Near-Collision Close Calls Reported to the Aviation Safety Reporting System

Abstract

Close calls in aviation are frequent occurrences. Many reports have described encounters with unmanned aerial vehicles or conflicts due to increasingly congested airspace. The Aviation Safety Reporting System, developed by the National Aeronautics and Space Administration, contains many close call narratives. However, few theoretical frameworks facilitate analyses of close call reports. This article describes an examination of close calls within the ASRS over a three-year period (2014-2016). The authors analyzed 117 close call reports from the ASRS involving near-midair collisions. Using Bliss’s (2013) taxonomy, the reports were successfully analyzed in terms of category and severity level. Results indicated that nearly half of the close calls occurred during the approach phase of flight. Also, a disproportionate number of close calls were “Un-signaled” and “Event-Driven.” Report frequency was negatively associated with aircraft separation distance. Recommendations include modification of the close call taxonomy to account for events caused by lack of responding.