Air Traffic Controller Fatigue Endemic and Puts Safety of Flying Public at Risk
Air traffic controller fatigue remains a significant issue, made worse by controllers squeezing five eight-hour shifts into four days. The result is controllers fighting sleep while they stare at radar consoles.
There are ample reports of controllers not responding to pilots’ radio queries because they had nodded off, of other controllers having to respond to the pilots, and the most scandalous case to get public notice: the controller who reportedly made a bed on the floor of the control room, complete with blanket and pillows.
“We’re trying to get a hold of Knoxville approach or Knoxville departure,” radioed one pilot as he vainly attempted to reach the snoozing controller.
In Washington, DC, two airplanes landed at Reagan Airport after the controller fell asleep and was unable to radio the requisite landing clearance.
The Federal Aviation Administration (FAA) asked the National Aeronautics and Space Administration (NASA) to study the issue, then it squelched the results. Repeated requests for the study resulted in its being belatedly made public 18 July. The FAA poor-mouthed the study, claiming, “Concerns remain that the academic approach used by NASA did not sufficiently integrate an understanding of the air traffic 24-7 operational environment with a scientific approach.” A plain reading of the paper reveals just the opposite (see ‘Controller Alertness and Fatigue Monitoring Study’, report DOT/FAA/HFD-13/001; see www.faa.gov/data_research/research/media/NASA_Controller_Fatigue_Assessment_Report.pdf). The results — cutting through the dry bureaucratic language — are troubling.
The study found that nearly a fifth of controllers blamed fatigue for committing “significant errors” in their duties. Controllers averaged less than six hours of sleep, with less time sleeping before working at odd hours.
Scheduling practices allowed controllers to work five 8-hour shifts over 88 consecutive hours. In contrast, the average non-controller worker will undertake the same duty over 104 hours.
One popular work shift, dubbed the “rattler”, enabled controllers to squeeze five 8-hour shifts into four 24-hour periods. This schedule allows controllers to enjoy a three-day weekend. In the “rattler” schedule, a controller ends an 8-hour shift at 2 p.m., and then returns to duty at 10 p.m. the same day.
Here is a typical work schedule that includes the “rattler”:
|Day||Shift Schedule||Hours between shifts|
|Monday||3-11 p.m.||Between 74-81 hours off during the preceding weekend, depending on previous week’s watch schedule|
|Tuesday||2-10 p.m.||15 hours off from 11 p.m. Monday|
|Wednesday||7 a.m. – 3 p.m.||9 hours off from 10 p.m. Tuesday|
|Thursday||6 a.m. – 2 p.m.||15 hours off from 3 p.m. Wednesday|
|10 p.m. – 6 a.m.||8 hours off from 2 p.m. Thursday|
|Friday||Off duty as of 6 a.m.|
Note that this schedule guarantees maximum circadian disruption; that is, it requires alertness during the hours from midnight to dawn when the body is programmed — through millennia of evolution — to sleep. As the NASA study noted, “This circadian challenge is compounded by the fact that it is commonly difficult to sleep during the day before the midnight shift, when humans are biologically conditioned to be alert and awake.”
In addition, controllers often work overtime, either as extra hours tacked on to a regular watch or as extra days. As the NASA study observed, “This yields a 6-day schedule with potentially one day off before the next week’s schedule begins.”
The controllers’ response to a survey item was revealing about trust in leadership. Instead of “usually”, the overwhelming response was “sometimes” to the statement, “When I am fatigued at work, I feel comfortable asking for a break or rotation.”
There are obvious solutions to the supposed “dilemma” of controller scheduling and fatigue:
We are long past the point where schedules should be dictated by convenience instead of science. The FAA’s pooh-poohing and dismissing the NASA study for its “academic approach” is simply an admission that other factors than what is known about circadian rhythm drive the controllers’ work schedule. Life-critical decisions are entrusted to people too often fighting off sleep.