Mode Aviation
Reference No. AR201900007
Date reported 15 February 2019
Concern title Potential fatigue levels of air traffic controllers at Sydney Tower
Concern summary

Potential fatigue levels of air traffic controllers at Sydney Tower.

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

Reporter's concern

The reporter has raised a safety concern regarding the potential fatigue levels among controllers at Sydney ATC tower. The reporter states that there is insufficient staff to enable workers to take effective breaks away from the work environment and to cover unplanned shifts, i.e. to cover sick leave, training, etc.

The reporter advises that the current Fatigue Risk Management System used to assess a controller’s suitability to cover a shift or work an additional shift, primarily takes into consideration the fatigue levels a controller will encounter for one specific shift. It does not take into consideration the cumulative effect of fatigue once the additional shift has been added to the controller’s remaining rostered shifts. The reporter is concerned that controllers working long sequences of consecutive shifts with an elevated fatigue potential will result in a controller working when fatigued. The reporter is also concerned about the long-term health impacts of controllers working long sequences of consecutive shifts with an elevated fatigue potential.

The reporter states that approximately 40% of all medium and high rated potential fatigue levels across Airservices are attributed to controllers at Sydney Tower, although Sydney controllers only account for 4% of the workforce. The reporter is concerned that these figures may be an indicator to heightened levels of controller fatigue at Sydney Tower. The reporter is concerned that audit and assurance mechanisms have not identified staff shortages as having a potential to increase fatigue-related risk.

Operator's response (Operator 1)

We appreciate the opportunity to respond to the above referenced report.

With respect to the reporter's comments on the cumulative effects of fatigue, our work scheduling requirements are designed to address the multiple and inter-related fatigue inducing factors. These include maximum duty periods, minimum time off between consecutive shifts, the number of consecutive shifts which can be worked, shift rotations and time of day. The development of shift cycles takes into consideration the quality and quantity of sleep opportunities, with rosters assessed using a bio-mathematical model against a nominated threshold.

Tactical risk assessment procedures are applied in response to changes to shifts/hours of work and/or changes to the number or pattern of shifts/days. These assessments are designed to identify the likelihood of transient and cumulative fatigue for the shift under consideration and any upcoming shifts. In cases of elevated fatigue risk, our systems require that controls are applied to mitigate the impacts. Analysis of actual worked shifts at Sydney Tower reflects a stable long term trend in fatigue exposure (as measured by FAID). Such results are consistent with other 24 hour locations and well within the fatigue-risk tolerance on which our Fatigue Risk Management System is premised.

The report states that approximately 40% of all Medium and High rated potential fatigue levels are attributed to controllers at Sydney Tower, although Sydney controllers only account for 4% of the workforce. We are unclear as to how these statistics were generated. Our analysis shows that in 2018, that of all shifts categorised as having elevated fatigue-risk potential (i.e. Medium or High), 16% were attributed to Sydney Tower.

In regard to the reporter's concern in relation to staffing levels, our workforce planning is premised on numbers of controllers required to cover all shifts, including breaks, leave requirements both planned and unplanned, and training. We term this the mature staffing requirement. For Sydney Tower this is 38.5 Full Time Equivalent (FTE). In 2018, the FTE assigned to Sydney Tower averaged 41.6, and was 39.2 in February 2019. In February there were 3.8 FTE unavailable due to factors including training, performance, illness and other long term leave. We continue to address this short term issue through both permanent and short term transfers into Sydney Tower as part of our workforce deployment processes.

Regulator's response (Regulator 1)

  • CASA regulates Air Traffic Control under CASR Part 172.
  • CASR 172.110 requires Airservices to have sufficiently trained personnel at all times to provide ATC in accordance with the regulations and Annex 11.
  • CASR Part 172 and the subordinate MOS do not require Airservices to have a Fatigue Risk Management System (FRMS).
  • However, CASR 172.080 requires compliance with provider’s Operations Manual.
  • Airservices Part 172 operations manual (AA-OPSMAN-172) section 6.1 (b) and (c) refer to Airservices FRMS and Principles of Rostering, therefore CASA may issue findings against Airservices documents.
  • CASA have conducted two recent surveillance activities of Sydney Tower with no FRMS related findings and staffing numbers at the time of surveillance sufficient to provide ATC in accordance with the regulations and Annex 11.
  • The foreword to Annex 11, Edition 15, July 2018 requires implementation of the FRMS Standard by 5 November 2020.
  • CASA and Airservices will collaborate to implement the new FRMS standard.
  • Occurrence data has not revealed an increase in incident rates or Fatigue as a contributing factor.
  • Airservices provided a strategy to CASA to ensure there are sufficient trained personnel for Sydney Tower.
  • In accordance with CASA Surveillance Manual (CSM), CASA continues to conduct planned surveillance of Sydney Tower.

ATSB comment

The reporter provided feedback to the ATSB regarding their interpretation of the FACT data. The ATSB reviewed the information provided and determined it was not necessary for Airservices to provide further comment around their analysis process.

Last update 30 August 2019