Aircrew Fatigue, Sleep Need and Circadian Rhythmicity

Publisher Summary Fatigue cannot be eliminated from aviation operations because of the inherent schedule requirements for transmeridian travel, irregular and unpredictable schedules, long duty days, early report times, night flights, and reduced sleep opportunities. Many commercial aviation industry practices induce fatigue via sleep loss and circadian misalignment in flight crews. Therefore, there is a need to develop scientifically valid fatigue-management approaches to mitigate sleep loss, enhance alertness during extended duty periods and cope with circadian factors that are primary contributors to fatigue-related aviation incidents and accidents. This chapter begins by reviewing the homeostatic and the biological processes that regulate sleep, fatigue and alertness. Building on this foundational material, evidence is presented to demonstrate how sleep loss and circadian misalignment contribute greatly to fatigue and performance risks in short haul, long haul and ultra long range flight operations. The chapter concludes with a discussion of scheduling approaches, countermeasure application and fatigue management systems and technologies that can be used, in combination, as part of a comprehensive approach for ensuring that fatigue is effectively minimized in human centered aviation operations.