Human Error and General Aviation Accidents: A Comprehensive, Fine-Grained Analysis Using HFACS

Abstract : The Human Factors Analysis and Classification System (HFACS) is a theoretically based tool for investigating and analyzing human error associated with accidents and incidents. Previous research performed at both the University of Illinois and the Civil Aerospace Medical Institute has successfully shown that HFACS can be reliably used to analyze the underlying human causes of both commercial and general aviation (GA) accidents. These analyses have helped to identify general trends in the types of human factors issues and aircrew errors that have contributed to civil aviation accidents. The next step was to identify the exact nature of the human errors identified. The following questions of interest were addressed: (1) Which unsafe acts are associated with the largest percentage of accidents?; (2) Has the percentage of accidents associated with each unsafe act changed over the years?; (3) Does the pattern of unsafe acts differ across fatal and non-fatal accidents?; (4) Do the patterns of unsafe acts for fatal and non-fatal accidents differ across years?; (5) How often is each error type the "primary" cause of an accident?; (6) Do seminal unsafe acts differ across years or as a function of accident severity (fatal vs. non-fatal)?; and (7) What are the exact types of errors committed within each error category, and do these types of errors differ across accident severity or seminal events? The purpose of this research effort was to address these questions by performing a fine-grained HFACS analysis of the individual human causal factors associated with GA accidents, and to assist in the generation of intervention programs. The report details the findings and offers an approach for developing interventions to address them.