In March 2011 Clockwork Research were invited to deliver the JAA course ‘An Introduction to Fatigue Risk Management Systems’ to a group of 18 Air Traffic Controllers, based in Abu Dhabi, the first time this course has been delivered to a group of ATCSs (Air Traffic Control Specialists). In this article Clockwork’s Managing Director, Dr Paul Jackson, discusses the issues of ATC fatigue and the role played by Air Traffic Controllers in managing the fatigue experienced by flight crew.

The potential impact of shiftwork and fatigue on ATCS alertness and performance has been recognised since at least the early 1970s, when the FAA commissioned research into the effects of the shift patterns then in operation (Melton et al., 1973) and the sleep patterns of Air Traffic Controllers (Saldivar et al., 1977). These studies, and the many studies conducted since, have highlighted that fatigue is still an issue, and can have a profound impact on many aspects of ATCS performance.

As with the management of pilot fatigue, the traditional approach for managing ATCS fatigue has been through imposing limits on hours of work, and regulations regarding the timing and duration of breaks, both during the working day and between consecutive shifts and blocks of duties. However, there is now general acceptance that prescriptive limits alone are insufficient to manage fatigue; focusing as they do on only one aspect of a multi-factored problem, and being based on arbitrary limits rather than science. Under guidance from the various authorities (e.g. ICAO, EASA, FAA) airlines around the world are now beginning to use an alternative approach: fatigue risk management systems (FRMS).

The JAA course is designed to provide delegates with a thorough grounding in the science of fatigue, and introduces fatigue risk management as an addition to prescriptive approaches.

Is fatigue a problem for ATCSs and if so, what effects does it have?
Despite there being limits on the number of hours that can be worked before a controller needs to take a break, and the number of consecutive duties that can be worked, this group all agreed that fatigue is still a significant hazard for ATCSs: 

“Sometimes, particularly early in the morning, it can be really bad”

Considerable research has explored the effects of fatigue on ability to perform cognitive tasks. Such research supports the descriptions of how fatigue impacts on ATCS performance described by this group:

“You find yourself losing concentration, struggling to make sense of what is displayed on the screens”

The group also highlighted that the effects of fatigue are not confined to performance at work:

“Driving home from a shift, I’ve found myself nodding off on numerous occasions”

Indeed, driver fatigue is one of the most frequently reported manifestations of the fatigue experienced by shiftworkers, and one that road accident research has shown often leads to tragic consequences, particularly for those returning home from a night duty.

What are the main contributors to ATCS fatigue?
The main contributors to fatigue identified by this group were related to their shift patterns (this group work two 12-hour days, followed by two 12-hour nights, then 2 days off). The combination of long hours and consecutive duties, particularly consecutive nights, was highlighted as being especially difficult to cope with.

Running a 24/7 operation such as ATC brings with it particular challenges with regards to fatigue. We know that alertness is at a minimum during the early hours of the morning (the ‘Window of Circadian Low’ or WOCL), and for ATC this is a particularly difficult time. For the Abu Dhabi group the time around 0500 – 0600 is one of the busiest times of the day, and it also coincides with when the night and day shifts are swapping over. Those responsible for managing the fatigue of this group of ATCSs had recognised the elevated risk associated with this time of the day and had developed some simple, but practical strategies to manage the risks, such as taking extra time and care during the handover between the two shifts.

At the recent Fatigue in Transportation conference that took place in Fremantle in Australia, fatigue expert Professor Drew Dawson cited examples of similar informal strategies being employed in a variety of work settings including maritime, road transport, accident and emergency and on-call healthcare. As Professor Dawson explained, for industries providing critical services, such as ATC, the requirement to provide a 24/7 operation make fatigue inevitable, and not operating at times when fatigue is significant just isn’t an option. In such situations, employees often put in place simple, informal, but effective processes for managing their fatigue risk, culminating with a re-proceduralisation of work practices or the work environment, to enable the operator to proceed without fatigue translating into adverse outcomes.

Do ATCSs have a role to play in managing pilot fatigue?
In addition to experiencing fatigue themselves, the Abu Dhabi group also highlighted how they frequently identify fatigue in the pilots with whom they are communicating:

“You can hear it in their voices.”

“They don’t hear the instructions you are giving them, they hear what they want to hear.”

Moreover, the group all agreed that they have an important role to play in managing pilot fatigue:

“A pilot suffering from fatigue may compromise the safety of his aircraft. But for us, his actions are far more widespread – they have the potential to compromise our entire airspace, so individual pilot fatigue is definitely something we have to be aware of.”

This issue was discussed in detail during one of the exercises used in the course; an investigation of the go! Airlines (Flight 1002) incident that occurred in February 2007, when both pilots fell asleep and missed their destination before waking up and returning for a safe landing. During that incident air-traffic controllers frantically radioed the flight crew for 18 minutes without response from the pilots.

As well as identifying possible controls that an airline could implement to prevent such an event occurring in the first place, the incident investigation performed as part of the FRMS course sought to identify barriers that could have been implemented to prevent the undesired event (i.e. the pilots falling asleep) resulting in an adverse outcome. Previously, when I have delivered this course to pilots and airline management the discussion has centred around the measures that could be implemented by the airline, other crew members and the pilots themselves – there has been little discussion of the role of ATC. This group, by contrast, highlighted the crucial role that the ATCSs in this incident played, and argued that still more could be done in such situations, with the right technology and training.

As a result of the positive feedback received for this course Clockwork is now developing a course specifically tailored to the particular needs of ATC, with a view to running a repeat later in 2011. To receive more information about the next ATC FRMS course please contact us.

References
Brown, D. (2006) Managing fatigue risk: are duty hours the key to optimising crew performance and alertness? Proceedings of the Flight International Crew Management Conference 2006, Brussels, Belgium.

Melton, C.E. Jr., McKenzie, J.M., Smith, R.C., Polis, B.D., Higgins, E.A., Hoffmann, S.M., Funkhouser, G.E., and Saldivar, J.T. (1973) Physiological, Biochemical and Psychological Responses in Air Traffic Control Personnel: Comparison of 5-day and 2-2-1 Shift Rotation Patterns. (Report No. DOT/FAA/AM-73/22). Washington, DC: Federal Aviation Administration.

Saldivar, J.T., Hoffmann, S.M and Melton, C.E. (1977) Sleep Patterns in Air Traffic Controllers.  (Report No. DOT/FAA/AM-77/5). Washington, DC: Federal Aviation Administration.