Alcohol is a widely used drug, and its abuse is a serious public health problem. Alcohol has many widespread effects on the body, and impairs almost all forms of cognitive function, such as information processing, decision-making, attention and reasoning. Visual and vestibular functions are also adversely affected. The performance of any demanding task, such as flying an aircraft, is thus impaired by the effects of alcohol. Many studies have shown a significant proportion of aircraft accidents associated with alcohol use. Alcohol increases the risk of spatial disorientation, hypoxia and poor +Gz tolerance. Many studies have consistently shown significant detrimental effects of alcohol on pilot performance, both in the acute stages and in the post-alcohol period for up to 48 hours. Even low doses of alcohol can lead to reduced performance. While a pilot may legally fly 8 hours after drinking, the residual effects of alcohol may seriously impair their performance, especially in high work load and demanding situations.
Australian Transport Safety Bureau reports, (Mar 2004)