The Normal Operations Safety Survey (NOSS): Measuring System Performance in Air Traffic Control

This paper discusses a field observation tool called the normal operations safety survey (NOSS). The air traffic control (ATC) system, through its equipment, procedures, and training, is designed to function in a particular manner. A system as complex and dynamic as ATC, however, does not always behave as designed. NOSS aims to provide a diagnostic of how the system actually behaves as opposed to how it was designed to behave. This is accomplished by using the threat and error management (TEM) framework to create a profile of the operating environment and how controllers discharge their duties within that environment. This paper discusses the development of NOSS, its contributions to a safety management system, and highlights some of the safety issues NOSS has identified in field trials.