ABSTRACT
Most civilian and air traffic control facilities in the United States use rapid shift schedules. These schedules have generally been chosen for social reasons. Safety concerns have been raised because the air traffic controllers (ATCs) often carry an acute sleep dept onto the night-shift where they have little active work to do as they sit in the dark at the nadir of their circadian rhythms. This paper reviews advancing and delaying rapid shiftwork schedules, ATC workload factors as they relate to error rates and safety, and potential countermeasures. Recent studies indicate that ATC performance declines on the night-shift and that ATCs may be falling asleep while on-duty. There is indirect evidence that ATC error rates are highest on the night-shift. There are only limited studies which have evaluated potential countermeasures. The operational significance of the problems associated with ATC shiftwork is not yet clear. Further study is needed