An Analysis of in-Flight Impairment and Incapacitation in Fatal General Aviation Accidents (1990–1998)

In-flight impairment and incapacitation are defined as states wherein the pilot's ability to effectively control the aircraft is adversely affected. They are of special concern in general aviation given there may be no second pilot to take over the controls. The purpose of the present study was to examine the characteristics of fatal general aviation accidents associated with impairment and incapacitation. A comprehensive review of 2,696 fatal general aviation accidents from 1990–1998 using database records maintained by the NTSB and FAA yielded 216 accidents (8.01%) that had some form of impairment/incapacitation or physiological causes mentioned in the accident report. Impairment due to drugs (n = 88, 40.7%) and alcohol (n = 68, 31.5%) were the most common causes. Cardiovascular causes were cited in 12.03% (n = 26) of the cases. Significant relationships were observed between age and impairment/incapacitation due to alcohol, drugs, and cardiovascular causes. Some disparities were observed between the prevalence of alcohol in toxicology samples and alcohol impairment being cited in the accident report as a contributory factor. The analysis provides some insight into the possible causes of pilot impairment and incapacitation in general aviation. Education and risk management training may serve as effective interventions.