In the aviation industry, commutes that involve travel across multiple time zones have the potential to exacerbate the fatigue associated with commuting, as can chronic restriction of sleep for multiple days prior to commuting. It is important to recognize that these fatigue effects can be mitigated to some extent by following good sleep hygiene practices2 in the period between the end of the commute and the time of reporting for duty. Due to a lack of relevant data, it is unknown to what extent good sleep hygiene practices are followed by commuting pilots to ensure they are alert during their postcommute flight and duty periods.3
Extensive scientific evidence exists on the negative effects of fatigue on the performance of many cognitive tasks, including those essential for safely operating a commercial aircraft. The adverse effects of fatigue induced by sleep loss include maintaining wakefulness and alertness; vigilance and selective attention; psychomotor and cognitive speed; accuracy of performing a wide range of cognitive tasks; working and executive memory; and higher cognitive functions, such as decision making, detection of safety threats, and problem solving; and communication and mood (Harrison and Horne, 2000; Thomas et al., 2000; Durmer and Dinges, 2005; Philibert, 2005; Banks and Dinges, 2007, 2011; Goel et al., 2009b; Lim and Dinges, 2010).
The Institute of Medicine (IOM) defines fatigue as “an unsafe condition that can occur relative to the timing and duration of work and sleep opportunities” (Institute of Medicine, 2009, p. 218). It further states:
In healthy individuals, fatigue is a general term used to describe feelings of tiredness, reduced energy, and the increased effort needed to perform tasks effectively and avoid errors. It occurs as performance demands increase because of work intensity and work duration, but it is also a product of the quantity and quality of sleep and the time of day work occurs.
Pilot commuting practices and individual day-to-day experiences can be quite variable, depending on many factors. The extent to which pilot commuting is contributing to fatigue at work—by reducing sleep time, extending wake time prior to duty, or interrupting a habitual nocturnal sleep period—is not known.
2Good sleep hygiene practices generally refer to those behaviors that effectively control all behavioral and environmental factors that precede sleep and may interfere with sleep, to ensure the sleep is as restful as possible, in order to promote daytime alertness or help treat or avoid certain sleep disorders (see Thorpy, 2011).
3The committee did not consider the use of sleeping medications by pilots during commutes prior to duty because the FAA has restrictions on pilots’ use of Federal Drug Administration-approved prescription sleep medications, over-the-counter drugs, and supplements for sleep.