Nuisance Alerts in Operational ATC Environments: Classification and Frequencies

Abstract

Nuisance alerts can cause many problems in operational settings. They are distracting and can lead to desensitization. In Air Traffic Control (ATC), there has been much anecdotal evidence regarding the high rate of nuisance alerts in facilities, but there have been few formal studies to evaluate this problem. In this study, we measured the rate of nuisance alerts in en route and terminal ATC facilities. After calculating the average duration of alerts, the percentage of alerts that receive a controller response, and the timing of responses to these alerts, we estimate that 62% of Conflict Alerts (CAs) and 91% of Minimum Safe Altitude Warnings (MSAWs) in en route, and 44% of CAs and 61% of MSAWs in terminal are unnecessary. Using human factors principles, we make recommendations for improving the accuracy and utility of ATC alerts.