A Survey Methodology for Measuring Safety-Related Trends in the National Airspace System

Making informed judgments about the effects of technological, human, or environmental changes on civil aviation requires reliable information. The National Aviation Operational Monitoring Service (NAOMS), a research project under NASA’s Aviation Safety Program, developed and tested a survey methodology designed to provide statistically reliable information on changes over time in safety-related events in the national airspace. Such information would aid decision makers in determining what areas required attention. To evaluate the NAOMS concept, data from nearly 20,000 randomly selected air-carrier pilots were collected over 3 years. Results demonstrate that the NAOMS approach can reliably identify changes over time in the rates of safety-related events.