Human factors analysis of accidents involving visual flight rules flight into adverse weather.

Background: General aviation (GA) accident statistics indicate that visual flight rules (VFR) flight into instrument meteorological conditions (IMC) is a major safety hazard. However, little research has been conducted to identify the factors that influence VFR pilots' decisions to risk flying into deteriorating weather. The purpose of the present study was to further examine the causes of GA accidents associated with VFR flight into IMC.
Method: A comprehensive review of GA accident reports maintained by the National Transportation Safety Board (NTSB) was conducted to identify accidents involving VFR flight into IMC between January 1990 and December 1997. These accidents were compared with other GA accidents that occurred during the same time period.
Results: Analyses of these accidents revealed that VFR flight into IMC accidents were more likely to involve less-experienced pilots and to have passengers aboard the accident aircraft compared with the other GA accidents. In addition, most VFR flight into IMC accidents were considered by the NTSB to have involved intentional flight into adverse weather by the pilot.
Discussion: These findings are interpreted in terms of their implications for the underlying causes of VFR flight into IMC, including situation assessment, risk perception, and social pressure. Intervention programs that address all of these factors are needed.