Mode Aviation
Reference No. AR201700058
Date reported 29 June 2018
Concern title Controller fatigue in Melbourne Centre during single-person night shifts
Concern summary

The concern related to Air Traffic Controllers on single-person night shift falling asleep at the console in Melbourne Centre.

Industry / Operation affected Aviation: Airspace management
Concern subject type Aviation: Air Traffic Control

Reporter's concern

The reporter expressed a safety concern related to the safety of airspace in the Melbourne region due to controllers on single person night shift falling asleep at the console in the Melbourne Centre while on night shift.

This concern was raised in 2016 in REPCON AR201600052 and in response to this, Airservices conducted a review into night shift practices in the Southern Operations Centre. The reporter has advised that controllers in a single person position are continuing to operate consoles without a break during an overnight shift. They advised that on numerous occasions they have not even been offered a short break by another group. Airservices management have added additional aisle managers on nightshift, but they seem to be more concerned about their and the shift supervisor breaks than the controllers on the floor.         

The reporter suggested that there is enough scope in the roster to provide two people on night shift for most sectors, but if this not possible then an extended break (longer than 20 minutes) is required. This would mean that TIBA procedures should be enacted, but this could be done safely.       

The reporter also advised that if a sector is double-manned the controllers can choose to split the hours of the nightshift as they wish. If they elect to operate for more than 2 hours, they have to sign a form which says they are willing to do so. Yet on single person nightshifts, nobody is asked to sign a form, and it is not required, even though they operate for more than 2 hours (8 in total) often without a single break.

Reporter comment: I cannot stress enough how unsafe the procedure is. Controllers are sleeping on console every night, some have been signed off by their doctors due to fatigue.

Named party response:

Airservices Australia (Airservices) appreciates the opportunity to respond to the reported safety concern regarding fatigue levels on single person night shifts in the Melbourne Centre.

As previously reported to the ATSB, single person night shift staffing is an ongoing practice amongst a large number of groups in both Southern and Northern operations.

Following our previous correspondence to the ATSB, Airservices reviewed the practice of single person night shifts at Melbourne Centre. The review confirmed that the processes and practices for night shift rostering/staffing and fatigue management are appropriately followed in determining and monitoring the night shift staffing arrangements.


Since responding to AR201600064, Airservices has conducted a Melbourne Air Traffic Services Centre (ATSC) Night Shift Review which resulted in a number of actions entered and tracked through our Corporate Integrated Reporting and Risk Information System (CIRRIS). Southern Operations implemented additional night shift supervision in the Melbourne ATSC through the use of Shift Manager endorsed staff on 1 May 2017, in addition to that already provided by the System Supervisor. Expectations associated with the position include regular floor walking and welfare checks on staff throughout the night. Airservices confirms that the recent Post Implementation Review for night shift supervision did not highlight any instances, reported or observed, of operational controllers sleeping at the console.

As the additional night shift supervisory position is not mandated but is rather an additional level of supervision, there have been a small number of occasions (approximately 7 between 1/5 - 26/9) where the position has not been manned. In these instances, when able, additional supervision had been provided by suitably endorsed staff on a break from other operational positions.

Single staffed night shift units within the Melbourne ATSC have been moved, as part of the Adelaide TCU transition, into an aisle where there are more sectors who have greater visibility of single staffed position activity. The added benefit of being in close proximity to units with dual staffing is that those are the units who offer the short breaks to single staffed night shift units. Airservices confirms that this has assisted the coordination and management of the short break timing between the controllers. The System Supervisor, Shift Manager and Flight Data Coordinator (FDC) are single staffed positions and as such they coordinate their short break rotation so as to be available to manage the offer of short breaks to single staffed ATC units outside the times short breaks are normally offered by dual staffed units.

Airservices is trialling the use of non-operational electronic equipment, under set conditions, for single staffed night shifts to assist with fatigue management. This is a 3 month trial and current feedback on the practice is positive.

The suggestion by the reporter of using Traffic Information Broadcast by Aircraft (TIBA) to provide extended breaks for single staffed night shift units does not take into account the required service levels Airservices must uphold and the fatigue management and sleep science that informs Airservices roster design. Additionally TIBA does not allow for the monitoring of active frequencies or intervention and assistance as required by a licensed controller that the short break procedure allows for. While there are long periods of inactivity on single staffed night shift units in the Melbourne ATSC, enacting TIBA may result in aircraft requiring short notification entry (i.e. due to medical or mechanical emergency) into TIBA airspace not receiving the level of service that they require.

Work schedule design

All rosters are designed at a strategic level based on a solid understanding of fatigue and sleep science so as to provide appropriate staffing levels for the management of operations in a safe, efficient and expeditious manner whilst mitigating the operational risks associated with fatigue. We create rosters to enable an appropriate work/life balance while considering the operational requirements. Those operational requirements are assessed in relation to operational workload which includes, amongst other things, traffic levels, traffic complexity, number of operational positions used, endorsement mix, and type of operations undertaken.

The default staffing for all night shifts is a single person but this may be increased dependent on the factors above and their impact on night shift operations.

To ensure that night shift staffing remains relevant, an assessment is completed each year on the night shift staffing composition for units with multi staffed night shifts. In 2017, the Melbourne ATSC night shift staffing assessment was also conducted for single staffed night shift units and resulted in no recommended changes to night shift staffing. Ongoing monitoring of traffic levels and complexity on all units occurs throughout the year to assess and, if appropriate, manage recommended changes.

Single staffed night shift positions are assessed as having extremely low traffic volume with very low complexity and is based on known traffic patterns and actual traffic captures showing maximum and minimum numbers of aircraft in a given volume of airspace. This allows staff on single staffed night shifts to move around from the console, use non-operational electronic equipment, and manage their short break requests to take multiple coffee/toilet breaks as required when there is no traffic within or pending to enter their volume of airspace.

Those units where it has been deemed appropriate to have multiple staff on night shifts are subject to the same strategic assessment as those on single staffed night shifts but due to the complexity and/or volume of traffic it has been decided that single staffing is not an appropriate way to manage the shift. Units with multi staffed night shifts have a default in shift break pattern of a maximum of 2 hrs on position. This is due to staff not being in a position to be able to take a break away from the console in a way similar to single staffed units due to the significantly higher levels of traffic volume and complexity. Controllers may request to exceed this timeframe but are required to conduct a risk assessment in conjunction with the Shift Manager or System Supervisor who will either accept the assessment and fatigue risk or recall the additional controller to manage the rotation of breaks differently. The risk assessment for extending past 2 hours on position is designed to manage a tactical change to the strategic design of the roster. The risk assessment looks at the tactical components of a shift (traffic, ATM system, weather, complexity, fatigue etc) so as to accurately assess if an extension beyond 2 hours is appropriate. The risk is accepted by the Shift Manager or System Supervisor as it is a change away from the strategic design of the roster.

The extremely low traffic volume and minimal complexity of units with single staffed night shifts do not warrant additional staffing to manage the operations. Management of fatigue is through a number of methods including roster design, the ability to ask for and make use of a short break, the ability to move from the console, and the use of non-operational electronic equipment, reading material, puzzles etc (during the regular periods of no traffic). Workforce levels for roster groups are designed to make efficient use of staff based on traffic levels, traffic complexity, number of operational positions used, endorsement mix, and type of operations undertaken. As such increasing staffing levels to provide dual staffed night shifts would create significant efficiency issues, increase the number of night shifts worked on the group per controller, and have flow on effects in areas like proficiency and recency due to overstaffing of units.

Shared responsibly for safety

Controllers are required to attend work fit for duty to complete the entire shift in an operational capacity as part of their ATC Licensing requirements, this includes night shifts.

Staff are also required to advise if, throughout their shift, they become unfit for duty.

Airservices fosters a positive reporting culture and has specific safety requirements whereby, if any staff member observes a safety occurrence or unsafe practices i.e. loss of separation, incorrect coordination, controller falling asleep on position, or a controller presenting unfit for operational duty, must be reported through a Shift Manager, System Supervisor, Operations Rooms Manager, ATC Line Manager or entered directly into CIRRIS.

Airservices has conducted a review of the CIRRIS occurrences related to Melbourne centre staff on night shift. There were no occurrences involving ATC falling asleep during night shift recorded in CIRRIS.

Regulator's response (Regulator 1)

CASA has reviewed the REPCON and provides the following comments.

CASA regulates Air Traffic Control under CASR Part 172;

  • CASR 172.110 requires Airservices to have sufficiently trained personnel at all times to provide Air Traffic Services in accordance with the regulations and ICAO Annex 11;
  • CASR Part 172 and the subordinate Manual of Standards (MOS) do not require Airservices to have a Fatigue Risk Management System (FRMS);
  • Airservices has a Safety Management System (SMS) in place which includes fatigue risk management procedures. However, this is voluntary and though referenced in the Operations Manual can be considered unregulated;
  • Single person night shifts are approved where an appropriate short break procedure is in place;
  • CASA is not aware of any safety issues with single person night shifts since the publication of the Airservices Southern Operations Night Shift Review approved in 2016; and
  • CASA will conduct surveillance at Melbourne Centre 23 – 26 October 2017 and will investigate these claims at that time.

ATSB comment

The ATSB received comments from the reporter to these responses and further questions were sent to Airservices.  The following is a summary of these questions:

Whilst it is understandable that Airservices would expect instances of sleeping on console to be reported, many are hesitant to do so in fear of repercussions. There has also been more than one occasion where controllers have tried to report this occurrence however have then been asked for date, time and name of the colleague who fell asleep. Many are unwilling to continue the report as they don’t want their colleague to be reprimanded for something they cannot control.

Controllers are ultimately unwilling to report:

  • Falling asleep at console
  • Incidences of not being offered a break
  • Unfit for duty during a shift

For fear of repercussions. 

In addition to this, there has also been active discouragement from management to submit fatigue reports hence why Southern Operations has almost none to show. Many can tell of instances where they have tried to report fatigue and their ALM/SM has intimidated them enough that they feel uncomfortable doing so. If there really was no problem of fatigue, why would controllers need to use REPCON as their only option?

The short break procedure is not an acceptable means of managing fatigue. The procedure would entail us handing over a sector, with traffic, to a manager who does not hold a license and likely has no experience in the type of traffic involved on our sectors. All the while, risking our own license. I feel it is inappropriate to expect a fully licensed controller to risk their own license and hand over to a non licensed controller, just so we can go to the bathroom.

The design of rosters and the science that has been used to develop them, does not appear to be readily available to employees of Airservices. Where would an employee find such information? Where has the research come from? Is there research into how many other ANSP centres use single man nightshift?

With regards to low traffic volume and complexity, are Airservices able to confirm when volume and complexity of sectors was last assessed? Was the data collected over an extended period of time? I would argue that whilst our sectors do have low volume, there is often a constant stream of traffic throughout a nightshift and therefore little to no opportunity to actually take a break.

 “Controllers may request to exceed this timeframe but are required to conduct a risk assessment in conjunction with the Shift Manager or System Supervisor who will either accept the assessment and fatigue risk or recall the additional controller to manage the rotation of breaks differently.”

The controllers on single staffed nightshifts seem to get no say in whether they work 2+ hours. The risk is accepted by the manager/supervisor yet nobody consults with the actual controller who has to work the 2+ hours. We, as controllers, are responsible for managing our own fatigue and being fit for duty but yet, Airservices takes away our ability to manage both these aspects.

How would Airservices manage a situation where a controller who is single staffing a nightshift decides mid-way through a shift that they are now no longer fit for duty? In the environment we currently work it, I doubt that this would come free of consequence for the controller.

In all of Airservices reviews, were controllers actually consulted?

When the controller is on a short break during their shift, who is responsible for the airspace – is the license of the controller on break being used to control the area?

Airservices response:

In response to your query, individuals must hold an Air Traffic Controller license and a valid Class 3 medical to provide a short break in accordance with the National ATS Administration Manual Section 1.4. They are not required to hold the endorsement for a particular sector but must have the required skills to provide a short break that is compliant with Airservices/CASA agreed procedures.

Responsibilities for the Endorsed Controller (the controller on break) are clearly defined in National ATS Administration Manual Section 1.4.

Last update 12 July 2018