Source: Aviation, Space, and Environmental Medicine, Volume 83, Number 1, January 2012, pp. 42-49(8) Scant data are available on the annual incapacitation rate of aircrew. This study analyzes all incapacitations occurring among UK commercial pilots, in flight and off duty, in 2004 to derive a baseline minimum annual incapacitation rate for the UK commercial pilot population. The annual incapacitation rate was 40/16,145 = 0.25%.