Why do I need to know about fatigue?
Fatigue is something that can occur in all professions. However, in Air Traffic Control (ATC) where a 24 hour service is required and safety must be maintained at all times, it is essential that air traffic controllers and air traffic engineers understand the potential risks of fatigue and know what they can do to manage these risks. Most air traffic controllers and many engineers work shifts and will already appreciate that aspects of shiftworking can increase fatigue risk. ATC requires consistently good human performance – for example, strong planning, good situation awareness, sound decisions, etc. As a controller or engineer becomes more fatigued, the risk that their performance will be impaired increases and ultimately fatigue can significantly compromise their ability to carry out their tasks safely.
What is fatigue?
Rather than propose a single definition of fatigue, it is better to consider a number of key points:
- Fatigue is a normal physiological state like hunger and thirst that cannot be suppressed. It is a signal that alerts us that we need to rest.
- Fatigue typically results from prolonged mental or physical exertion. Lack of good quality sleep and illness can also cause fatigue.
- Fatigue can affect a person’s performance and impair their mental alertness, which may lead to dangerous errors.
- Fatigue can be temporary (i.e. removed by rest or sleep) or chronic (i.e. building up over a long term and harder to get rid of).
There are three types of fatigue: mental, visual and physical. Operational air traffic controllers are mainly affected by mental and visual fatigue. Engineers could be affected by all three.
Recognising general signs of fatigue
Controllers and engineers may experience only some of the signs shown in the table below and may not necessarily associate them with fatigue.
Signs of fatigue
There are also quite obvious outward indications such as yawning, eyes closing or changed breathing patterns.
Fatigue can come on quite rapidly after a period of working, in which case the symptoms can be easier to detect. Alternatively it can build up gradually and the air traffic controller or engineer may not necessarily recognise that they have become fatigued.
Operational staff awareness of fatigue
Quite often there may be early tell-tale signs of fatigue in air traffic controllers, for example:
- Missing pilot calls or readbacks, possibly having to ask pilots or colleagues to repeat information.
- Forgetting routine tasks (such as strip marking or transferring an aircraft to the next sector).
- Starting to fall behind in planning, maybe being caught out or surprised by something that you would normally anticipate in good time.
As fatigue becomes more obvious, the warning signs could be:
- Not seeing an aircraft when planning from the radar due to narrowed attention.
- Confusing the steps of a plan, possibly having to change a plan.
- Missing warning indications.
- Impaired team working or leadership – not communicating well with colleagues or taking longer to tell others what to do.
- Finding it harder to concentrate on the ATC situation and being more easily distracted.
- Irritability - pronounced irritability and moodiness very often triggered by routine tasks or any other trivial stimulus.
If you see these signs in yourself or colleagues, it is important to consider that fatigue may be the cause. Air traffic engineers are likely to see other tell-tale signs of fatigue in their own performance. Air traffic controllers and engineers need to recognise the signs and know how to respond in order to keep their performance acceptable and the operation safe.
Recognising fatigue in operational staff
Operational managers or supervisors have a responsibility to monitor for fatigue in the operational staff they manage. They are in a good position to look out for signs of fatigue in their staff and will also be the person who may need to support staff showing symptoms of fatigue. Bearing in mind that an individual may fail to recognise or acknowledge that their performance is being degraded by fatigue, there are outward indications a supervisor or manager should look out for, including:
- Yawning and generally looking weary, closed eyes or even inability to stay awake.
- Less communication or interactions – becoming quieter and more withdrawn.
- Asking to carry out quieter or easier roles.
- Uncharacteristic task performance, such as inability to manage typical workload levels, an increase in mistakes.
- Uncharacteristic behaviours such as reduced motivation, irritability or moodiness.
Although performance can change for other reasons, it is always prudent for a manager or supervisor that detects one or more of the above to explore whether fatigue may be involved. They need to be prepared to take appropriate steps to give the air traffic controller an opportunity to rest.
Actions to minimise fatigue – being ‘fit for duty’
When working as an operational air traffic controller, it is important to take responsibility for managing your fatigue (just as you would manage your personal fitness in order to pass your annual medical check). This means that each individual controller and engineer has a professional responsibility to ensure that when they arrive for work they are ‘fit for duty’.
Both controllers and engineers need to consider the following fatigue management aspects:
- Develop a lifestyle that takes account of working shifts.
- Get in to good habits to ensure that sufficient ‘good quality’ sleep (i.e. deep and uninterrupted) is obtained.
- Prepare adequately before reporting for duty.
- Prepare carefully for night shifts.
- When carrying out operational duties, use breaks to counteract fatigue.
A lifestyle to manage fatigue
It is very important to achieve a good balance between what you do in and out of work in order to minimise the risk of being fatigued when at work. Your job as an air traffic controller or engineer requires you to sleep enough to be fit to perform at an acceptable level of alertness when on duty. For this to happen you have to plan carefully around your shifts:
- Establish a routine outside work and try to stick to it. For example plan regular times when you will spend time with family and friends between shifts.
- Plan for adequate periods when you will sleep.
- Discuss the need to be fit for duty with your family.
- Use a calendar to show family members what your shift patterns are so that they can work around these.
- Eat properly, keep hydrated and maintain fitness.
On days off, consider the following:
- Try to stick to normal sleep patterns but if you feel particularly tired, go to bed.
- Ensure any secondary employment does not interfere with your main job as a controller or engineer.
- If you do something physically or mentally strenuous outside work, give yourself plenty of time to recover before starting work.
- Try to take care with the intake of caffeine, alcohol and nicotine as these can disrupt sleep.
- During extended periods away from work (e.g. annual holiday), you may get into ‘bad sleep habits’. Try to get back to normal a day or two before returning to work.
The importance of sleep
Sleep is vital for your body to rest and repair as well as to give your brain a chance to ‘sort things out’ – it is thought sleep may be the time when the brain organises and stores information, replaces chemicals, and solves problems. A lack of good quality sleep will affect you. Most people require between 7 and 8 hours good quality sleep within each 24 hour period.
Listed below are several straightforward tips for good sleep:
- Try to develop a regular sleeping pattern that fits in with your shifts.
- Develop a regular pre-sleep routine.
- Sleep in a quiet, dark place which isn’t too warm.
- Avoid too much caffeine or alcohol before trying to sleep.
- Avoid a heavy meal before trying to go to sleep.
- It is easier to fall asleep if you are feeling relaxed – find relaxation techniques.
- If you are struggling to fall asleep after about 30 minutes, try reading a book (but nothing too exciting!), having a milky drink or maybe taking a warm shower or bath to relax you.
If you suspect that you have a sleep problem or disorder, seek expert advice.
Preparing for operational duties
You need to be ready to work in the ATC environment. It is vital that you plan your time to allow time for recovery from any mental and/or physical tasks you have done before starting your shift. You must also plan for an appropriate amount of time to sleep properly before returning to work. Other things to consider include:
- Be particularly careful to get enough sleep on the night before you start your first duty after being off from work.
- If you are worried that you may not wake up when you need to, use an alarm clock to take away this concern.
- Allow enough time to brief yourself with any new information when you arrive at work.
Making the most of rest breaks
It is important to try to take periodic breaks from your main task as this will help you to stay alert and manage fatigue. Air traffic controllers can use breaks to do other non-operational tasks (such as training reports, logging information) and some of these may actually add to your fatigue. Ideally breaks should give you an opportunity to recover from the mental, visual and possibly physical demands of your main air traffic control task. Ensure that the final 10-15 minutes of your break is entirely restful and relaxing, avoiding work-related or computer-based activities, e.g. internet browsing, checking emails, etc.
Individual considerations for night shifts
Night shifts challenge your normal ‘body clock’ (internal circadian rhythms). Naturally, you will feel most sleepy in the early hours of the morning (03.00-05.00). Individual needs for sleep and rest will differ with age and with general health. It is good to be aware of this and do certain things to make night shifts easier, such as:
- Many people prepare by sleeping or resting before a night shift.
- Eat a light meal a few hours before starting the night shift.
- Maintain alertness during a night duty by keeping up a dialogue within the team.
- If traffic and task demands are low, do not do things that are too distracting from monitoring the radar and radio (or system alarms if you are an engineer). Talking and reading usually help. Interactive games and videos may be too distracting.
- If possible, move between tasks periodically during the night shift to help vary activities.
- Organise regular breaks if available and use these effectively. If you are given enough time, and your unit allows it, take a short nap (no more than 30-40 minutes) but allow 15-20 minutes to wake up properly before returning to duty. (NB Sleeping or napping should only occur if these are agreed fatigue mitigation procedures at your unit).
- If naps are not possible, try to get some fresh air and exposure to bright light during a break.
Operational staff will naturally feel tired at the end of a night shift. If you feel that this may affect your ability to drive home, you should consider sleeping before your journey home.
Managers’ and Supervisors response to fatigue in operational staff
Fatigue will not just go away – it only gets worse. There are a number of steps that a manager or supervisor of operational staff can take:
- Talk to the controller or engineer and ask them if they feel fatigued.
- In a non-confrontational way, highlight any signs of fatigue that have been observed and explore the reason for these.
- Encourage the staff member to take possible fatigue seriously and refer them to the information and guidance made available to them.
- If necessary, agree a plan of action with them – possibly involving referral to a doctor or medical advisor.
Managers and supervisors should make sure that they educate themselves, in general, about fatigue. They should also realise that they too can become fatigued and this can impact their performance and ultimately the safety of the operation.
Operational air traffic controllers and air traffic engineers are susceptible to fatigue as they need to sustain accurate task performance over a shift period. As they typically work shifts, there will be times within the shift when they will need to maintain alertness when their natural circadian rhythms are making them drowsy. With careful lifestyle management outside work and fatigue management within the workplace, operational staff should be able to manage fatigue risk successfully.
Although their managers and supervisors have a role to play to support them, ultimately it is the responsibility of the controller or engineer to be aware of fatigue and to prevent fatigue from affecting their operational performance.
- Guidelines on Fatigue Management in ATC Rostering Systems, EUROCONTROL, April 2023
- Fatigue and Sleep Management, EUROCONTROL, January 2018
- We're Only Human (After All) - Brochure, EUROCONTROL, May 2018
- Safety Behaviours: Human Factors Resource Guide for Engineers - Chapter 5: Fatigue - CASA (Australia), 2013
- Operator's Manual: Human Factors in Aviation Maintenance, FAA, 2014
- Human Performance and Fatigue Research for Controllers, Gawron et al., 2011
- Advisory Circular 120-100: Basics of Aviation Fatigue, FAA, 2010
- Advisory Circular 117-3: Fitness for Duty, FAA, 2012
- Overview of EU Requirements on ATCO Fatigue Management
- CANSO Fatigue Management Expert Group
- Rostering: Fatigue Constraints and Guidelines