Do NTSB Statistics Support Current FAA Third Class Medical Policy?

Abstract

Third Class Medical Reform is currently being considered by the FAA and by Congress. This study analyzes past incident data gathered by the NTSB from 1982 to the present to determine if a link exists between the amount of time that has elapsed since a pilot’s medical certification and his or her likelihood of involvement in an incident or accident caused by medical incapacitation or impairment. A control population of 26,987 incidents was formed from all recorded incidents in which the pilot held a valid third class medical. This population was used to compare with a smaller population of 172 incidents for which the NTSB has determined that medical incapacitation or impairment not related to illegal drug or alcohol use was at least a factor. A Chi-Squared distribution returned a 17% probability that the two populations were identical. Incidentally, descriptive statistics of the control population show an unexpected negative linkage between recentness of medical certification and likelihood of being involved in an incident (R2 = .821). This counterintuitive finding indicates that recent third class medical certification correlates to increased pilot risk, rather than increased levels of safety.