I love hearing from readers who respond to my articles with questions, comments, and sleep stories of their own. My readers make up an incredibly bright, thoughtful community, with a lot of strong opinions and a lot of motivation to harness the power of sleep for mind-body health.
Your emails, tweets, and messages stand out for all sorts of reasons—they’re curious, thought-provoking, sometimes funny. And then, every so often, I get a message that sends a chill down my spine, as I did with the one I’m about to share with you.
Let me be clear: I don’t know this reader’s identity. This person wrote to me under complete anonymity. But what he says has the ring of truth, in alignment with the scientific evidence on shift work, sleep, and circadian rhythms. Here’s part of the note:
I work as an air traffic controller, and I’m curious how much you know about our schedule and if you’ve ever specifically studied it or been asked to comment on it. We work what are known as “Rattlers”, which is a varying schedule that begins with swing shifts, then day shifts, and finally an overnight or “mid”. And that is all in the same week, every week. Most weeks also include an overtime shift that can be any of those, because the air traffic system is critically understaffed and has been for a few decades. I’m concerned about the effect it has on my health, but it is clearly dangerous for the flying public as well.
To work for the FAA is to be complicit in a system you know to be unsafe. And nobody seems to care.
People do care: sleep experts like me care about this a lot, as do people who study and work in public safety. And I think the nearly 3 million people who fly every day in FAA airspace care a lot about how well-rested and mentally fresh its air traffic controllers are.
But the reader is worryingly correct about a number of issues:
Shift work is notoriously hard on sleep and increases sleep-related risks for compromised performance, and greater risk for accidents and errors.
Rotating shifts, like those the reader describes, are particularly harmful to sleep and circadian rhythms.
Sleep and circadian rhythm disruptions will compromise the performance of air traffic controllers (as well as pilots, train engineers, bus drivers, and anyone who gets behind the wheel of a car).
There’s nowhere near enough attention being put to these issues, and that puts us all at risk.
Let’s take a closer look at some of the recent history and science behind this issue.
The sleep rules for air traffic controllers – do they fall short?
Let me say this first, for some important perspective: air travel remains statistically an incredibly safe form of transportation. Recent years have demonstrated that air travel has been getting increasingly safe—both 2017 and 2018 are among the safest years on record for flying.
But the stakes are obviously incredibly high here. Sleep and healthy bio rhythms are major factors in performance for all of us. Our cognitive performance, including attention, reaction response times, and judgment, suffer when we’re lacking sleep and when our bio clocks are thrown out of sync. Protecting the performance of professionals directly involved in air travel, from pilots to ground crew to air traffic controllers, is of the utmost performance.
The Federal Aviation Administration, or FAA, which regulates all aspects of civilian aviation in the United States, sets policy regarding the work schedules for air traffic controllers. In recent years FAA policies have changed to reflect a growing awareness of the importance of sleep and reducing fatigue—but there’s reason to believe these changes haven’t gone far enough.
In 2011, the FAA made changes to the rules for air traffic controllers work schedules, increasing the minimum required time off between shifts from 8 hours to 9 hours. (This was in part a response to a series of reports of air traffic controllers falling asleep while working.) At the time, air traffic controllers themselves complained the FAA’s changes did not go far enough to remedy the problem of sleepiness and fatigue among their ranks. Notably, the FAA’s 2011 changes did not include making it permissible for air traffic controllers to take naps during their shifts to provide short-term relief from sleepiness and fatigue. That no-napping policy appears to remain in place to this day. And it appears that the 2011 FAA changes, implemented to reduce the intensity of the so-called “Rattler” schedules the anonymous reader references above, weren’t actually consistently enforced, as the reader’s note suggests.
Scientific research on the impact of shift work and sleeplessness on air traffic controllers—including studies by the FAA itself—have shown that fatigue and sleeplessness brought on by lack of rest and heavy workloads that unfold in rotating shifts contribute to compromised performance among air traffic controllers.
Studies show that rotating shifts—including those that rotate counterclockwise, as well as forward rotating shifts—make air traffic controllers more vulnerable to performance and health issues. This 2016 study found that controllers who work counterclockwise rotating shifts are at greater risk for compromised work performance, as well as health issues (obesity, lack of social interaction) that can further compromise sleep. A 2015 study by some of the same researchers found similar results, including reduced concentration and less sleep time on work days for air traffic controllers working rotating shifts. Other research also shows forward-rotating shift schedules among controllers lead to less vigor while on duty, as well as more confusion and fatigue.
Some of the most compelling scientific evidence showing the risks to air traffic controllers from sleep-depriving and bio-time disrupting work schedules comes from the FAA itself.
A study conducted by NASA for the FAA examined the sleep and fatigue issues among air traffic controllers—with some startling, disturbing results. (This study was placed in a final report in 2011, but the FAA kept the contents of that report unpublished for several years.) The study focused specifically on controllers who worked the “Rattler” schedule of tightly packed rotating shifts, the same shift schedule referenced by the reader who contacted me. This study found that of the nearly 20% of air traffic controllers who made significant errors in a given year, more than half reported their mistakes were the result of fatigue. More than 60% of controllers said they’d fallen asleep or had an attention lapse while driving either to or from work for an overnight shift. More than 30% told researchers that fatigue in their work was a “high” or “extreme” safety risk.
Over the duration of the workweek, air traffic controllers slept an average of 5.8 hours a night. And sleep amounts plummeted before overnight shifts, to an average of only 3.1 hours. Chronic tiredness was present for more than three-quarters of controllers in the study.
Of particular importance, the report noted this (I’m quoting from an Associated Press article about this study): “Even with 8 to 10 hours of recovery sleep, alertness may not recover to the full rested baseline level, but may be reset at a lower level of functioning.”
Translation: For controllers working these intense shift schedules, catching up on sleep—no easy task on its own—doesn’t guarantee to solve the problem and the risk.
More than a sleep problem
Why isn’t recovery sleep enough to restore full functioning for sleep-deprived air traffic controllers? We’ve seen a growing body of research that demonstrates the limits of recovery sleep, including the weekend catch up sleep that a lot of people rely on.
The problem goes beyond sleep. It’s also about bio time.
For air traffic control workers on rotating day-night shifts, it’s nearly impossible to maintain an in-sync bio clock and healthy biorhythms. Disruptions to circadian rhythms do more than impede and impair sleep. Problems with bio time have a ripple effect that interferes with almost every aspect of the body’s functioning, both physiological and cognitive
Just one example of the complex ripple effect I’m talking about: this 2009 study found that air traffic controllers working rotating shifts experienced bio-rhythm alterations to their circulatory system—including changes to heart rate rhythm and production of the alerting hormone cortisol—that diminished controller’s ability to perform intense mental focus at night.
This is more than a sleep issue, though sleep is a major factor in the health and safety risks associated with rotating shift work among air traffic controllers. There’s a broader, even more, complex bio time issue unfolding here, one that can’t be remedied by recovery sleep alone.
What can be done?
It’s difficult to look at the scientific evidence and feel confident that our agencies are doing all that they can to protect the health and performance of air traffic controllers, and with that, public safety.
Listen to the people on the job. I hope the FAA is paying attention to what its controllers and other airline personnel (including pilots) are saying, in public and in private, about their schedules and their ability to maintain a sleep routine.
Let the science guide policy. There’s no lack of scientific evidence about the damaging effects of shift work and sleeplessness on the health and safety of the people who work these schedules. The airline industry isn’t alone in facing the challenges of meeting the need for high-skilled, high-intensity, ‘round the clock coverage for critical jobs. It’s a challenge that faces all of our most public safety spheres, from the transportation industry at large, to health care and law enforcement. Obstacles arise around cost, internal politics, and resistance to change that comes from institutional cultures. Our institutions must work to overcome these obstacles to allow work conditions to align with the limits of what the human body can and can’t do, based on the best scientific evidence available. And we must put even more attention to the scientific study of sleep, biorhythms, and performance in these critical public safety industries.
Address the staffing shortage. This structural issue—one that appears to have been in place for a long time and is getting worse—has clear and critical impacts on sleep off for air traffic controllers, when shortages require controllers to work clusters of shifts.
Reduce and revise rotating shift schedules. When people constantly rotate between days and nights for sleeping and activity, maintaining healthy circadian rhythms is virtually impossible. The body is constantly receiving a different set of cues, and our biosystems just can’t keep things straight. The best-case scenario? Eliminating shifts that rotate between day and night altogether. Short of that, building in more rest time between shift time changes can make a difference.
Allow naps. The idea that sleeping on the job is a form of dereliction of duty, or a sign of laziness, is both outdated and harmful. For air traffic controllers and other people who work overnights and rotating shifts, structured periods of rest could have a significant positive effect on performance and well being. A 2000 study commissioned by the FAA itself found that naps for midnight shift air traffic controllers improved performance and reduced sleepiness. To extract the greatest benefits from napping, these rest periods must be timed—too brief and there won’t be a sufficient short-term cognitive benefit, too long and sluggishness will be an unwelcome side effect. (I’ve written about how all of us can use naps to our best advantage.}
All too often, our response to sleep and safety problems happens after the fact. Tragedy spurs us to make changes that data and experience showed us were worth making before a worst-case scenario transpired. It doesn’t have to be this way. This reader is right: we need to pay attention, and make changes, now
Have thoughts about sleep issues you’d like to hear from me about? Let me know!
Michael J. Breus, Ph.D., DABSM
The Sleep Doctor™