aviation that are not well covered by the other databases. In addition, carefully planned surveys can provide useful information not only about specific events, but also about the views and perceptions of the frontline personnel on flight operations. However, care must be taken to solicit information from these frontline personnel only when they are in a position to provide accurate and consistent responses.

Finding: A sample survey is a scientifically valid and effective way to collect data and track trends about events that are potentially related to aviation safety. The sample survey has several advantages over other, currently available, data sources:

• Sample surveys can be used to collect reliable information about all segments of civilian aviation. They can be especially useful for characterizing the safety of general aviation flights and the safety of flights of other segments of aviation where the data are more limited.

• Sample surveys have the potential to generate statistically valid information about operations that may or may not result in an accident or incident. This information would provide a useful reference point for studying other event data and for learning why some events lead to accidents while other, similar events do not.

• Government-sponsored sample surveys can produce data that are accessible to the public and can be analyzed regularly and independently.

However, information from any survey should be used in conjunction with other existing data to provide a holistic assessment of aviation safety levels and trends.