Do air traffic controllers need more sleep?

A government-sponsored report released last week said air traffic controllers are at great risk for fatigue and errors leading to accidents because of their work schedules.

Controllers routinely pack five shifts into four 24-hour periods. Schedules known as “rattlers” allow a controller to finish a fourth, daytime shift at 3 p.m. but then work a fifth and final shift of the week—overnight—only 8 hours later, on little or no sleep. Popular with controllers, the schedule allows up to 80 hours until the next work week begins.

The Transportation Research Board’s report expressed concern about the effectiveness of Federal Aviation Administration (FAA) practices to prevent its 15,000 controllers from suffering fatigue on the job, with a focus on the staffing-to-safety relationship and a concern for work scheduling. It recommended “providing a consistent basis for establishing work schedules that minimize or mitigate the safety risks associated with controller fatigue.” Although the FAA has plans to implement scheduling software for all its 315 facilities, it has no fixed timeline. Without a single standard, local towers and facilities now create their own staff schedules.

The National Air Traffic Controllers Association has defended current scheduling, citing a separate 2009 NASA study not publicly released. It claimed that “with proper rest periods,” the rattler “actually produced less periods of fatigue risk to the overall schedule.”

Mike Gunn, retired after 34 years with the FAA, said the problem of controller error boils down to the mundane issue of mental engagement: “Controllers have times when they are extremely busy and others when they are very bored.” This “feast or famine” work pace makes controllers more prone to errors because they are on idle—especially in low-traffic facilities experiencing a sudden burst of traffic.

“It is difficult to not be busy for a period of time then in a matter of minutes ‘spool-up’ for a very busy session,” he said. “Most individuals take a bit of time to start operating at peak performance and during that ‘spool-up’ time you can be prone to make mistakes.”

Hyper-busy facilities such as Atlanta’s Hartsfield-Jackson Airport, the busiest in the nation, have the advantage of keeping controllers “more focused on their duties due to the fact that the complexity and volume of traffic demand that degree of intensity,” said Gunn, now president of Wexford Consulting Group in Augusta, Ga., which specializes in evaluating aviation safety management systems.

Gunn admits controllers’ shifts have long been controversial, with many studies done and few recommendations implemented. The air traffic system’s original cohorts were former military controllers who loved the perk of a compressed work week. “Many different schedules have been reviewed over the years, but the proposals to enhance rest and safety were unacceptable to a majority of the controller workforce,” Gunn said.

If 2013 was the year of sleeping pilots, 2011 was the year of the sleeping controller: Nearly a dozen incidents revealed air traffic controllers sleeping on the job or not responding to calls from pilots late at night. In one case, two airliners landed at Washington’s Reagan National Airport without help—because the lone controller on the overnight shift was asleep. Since then, the FAA has prohibited solo controllers on overnight shifts at 27 airports and air traffic facilities and increased the minimum time between work shifts to nine hours. But most controllers likely don’t use the extra time to sleep.

An FAA “fatigue risk management program” encourages controllers to report errors by promising they will not be punished for honest mistakes. To detect practices that increase tiredness, reports get logged into a database for spotting trends. But when work moves into “feast” stage, controllers may get too busy to file reports—which don’t ask information on the controller’s schedule or details that would help determine whether a schedule actually contributed to errors.

Responding to the current report, the FAA’s said in a statement on Friday it is “adding limitations to its shift and scheduling rules” but did not clarify what they are.

The Associated Press contributed to this report.