Expert industry group publishes fatigue guidance

The strategic use of coffee and napping on site is being recommended for controllers whose sleep at home is disrupted by a newborn baby.
The personal fatigue mitigation strategy is just one recommendation in the first ever fatigue management guide for air traffic service providers produced by a cross-industry group comprising the Civil Air Navigation Services Organisation (CANSO), the International Civil Aviation Organisation (ICAO) and the International Federation of Air Traffic Controllers’ Associations (IFATCA) which applies the scientific principles related directly to controller fatigue management.
The guide presents the work of the ICAO Fatigue Risk Management Systems Task Force which was especially configured with ATC experts to develop controller-specific fatigue management provisions.
The group accepts that fatigue is an inevitable hazard in the round-the-clock working environment, leading potentially to a deterioration in human performance but insists that structured methods can address the safety implications of fatigue.
Fatigue science principles should therefore be built into rosters to enable factors such as the dynamics of sleep loss and recovery, the circadian biological clock, the impact of workload along with operational requirements can be taken into account.
“When fatigue science and operational knowledge and experience is applied in the building of controller schedules, fatigue hazards relating to scheduling can be predicted and minimised,” the authors state.
The expert group recommends that scheduling practices need to accommodate the effects of different types of shifts that are worked by controllers – early starts, day shifts, afternoon shifts, night shifts, etc – since the effects of sleep loss and fatigue are cumulative. The same applies to the effects of working a succession of different types of shifts across a roster period.
It has drawn up general scheduling principles based on fatigue science. They include:

  • The perfect schedule for the human body is daytime duties with unrestricted sleep at night. Anything else is a compromise.
  • The circadian body clock does not adapt fully to altered schedules such as night work.
  • Whenever a duty period overlaps a controller’s usual sleep time, it can be expected to restrict sleep. Examples include early duty start times, late duty end times, and night work.
  • The more that a duty period overlaps a controller’s usual sleep time, the less sleep he or she is likely to obtain. Working right through the usual night time sleep period is the worst case scenario.
  • Night duty also requires working through the time in the circadian body clock cycle when self-rated fatigue and mood are worst and additional effort is required to maintain alertness and performance.
  • Across consecutive duties with restricted sleep, controllers will accumulate a sleep debt and fatigue-related impairment will increase.
  • To recover from sleep debt, controllers need a minimum of two full nights of sleep in a row. The frequency and duration of recovery periods should be related to the rate of accumulation of sleep debt.
  • When on on-call, an increased likelihood of being called in may affect sleep recovery;
  • Controllers will require breaks to sustain performance during cognitively intensive periods of time-in-position.

The expert group said these sorts of principles can be used to develop scheduling rules to construct schedules for different units and notes that schedules need to be published sufficiently in advance to allow controllers to plan for duty and non-duty periods. While late roster changes are sometimes unavoidable, managers need to keep changes at short notice to a minimum and minimise their impact.
Where controllers are allowed to swap shifts, managers need to provide clear procedures for doing so, in order that prescribed limitations are not exceeded at the time of the shift swap or at a later time during the work schedule. Shift swapping also needs to be monitored to avoid conflict with scheduling principles or practices developed by the provider. The report also sets out stakeholder responsibilities to maintain a high level of safety including adequate resourcing for fatigue management.
“Everyone whose role in the organisation can influence controller fatigue needs to have an appropriate level of fatigue management information and training which should comprise basic scientific principles related to fatigue management and general sleep hygiene as well as content specific to the provider’s unique operational characteristics,” states the report.
This will include information on options for personal mitigation strategies and a good knowledge of procedures governing shift swapping, reporting in of “not fit for duty” declarations due to fatigue, or assigning unscheduled duties.
The guide also provides some examples of personal fatigue mitigation strategies (see below) that might feature in controller training. These have been classified as strategic countermeasures designed to be used at home or on-call and operational countermeasures that can be used in during duty hours.
Read: ICAO develops guidance on controller fatigue