Aviation safety issues and actions

Allocation of additional duty periods

Issue number: AO-2011-144-SI-02
Who it affects: All controllers
Issue owner: Airservices Australia
Transport function: Aviation: Airspace management
Background: Investigation Report AO-2011-144
Issue release date: 18 October 2013
Current issue status: Adequately addressed

Safety issue description

The air traffic services provider’s fatigue risk management system (FRMS) did not effectively manage the fatigue risk associated with allocating additional duty periods.

Proactive Action

Action number: AO-2011-144-NSA-056
Action organisation: Airservices Australia
Date: 18 October 2013
Action status: Closed

Airservices advised that:

the details in the report regarding fatigue risk management were in relation to the previous Fatigue Risk Management System (FRMS) which has been superseded by an updated system (referred to as FRMS 2) implemented from 30 July 2012. Airservices previously briefed ATSB on the key features of FRMS 2 and further information is included in Attachment 2.
The FRMS 2 has addressed the system limitations mentioned in the report, such as replacement of fatigue risk assessment calculator (FRAC) with an enhanced Fatigue Assessment and Control (FACT) tool and providing roster design criteria in addition to the Fatigue Audit lnterdyne (FAID). The implementation of FRMS 2 has resulted in improved work scheduling capabilities through a new rostering tool to limit cumulative fatigue and further mitigate fatigue-related risk.

In addition:

The FACT decision support tool embedded within the rostering tool assists managers and supervisors with effectively managing changes to work schedules to:

  • identify the most suitable individual for an Additional Duty/Extended Duty (AD/ED) or Change of Shift (COS)
  • assess situational factors that may affect potential fatigue-related risk, such as traffic complexity, weather, traffic volume
  • identify risk controls to be implemented to mitigate any potential fatigue related risk
  • record information about proposed changes to the published roster.


The FRMS 2 is closely aligned with relevant International Civil Aviation Organisation (ICAO) FRMS Standards and Recommended Practices (SARPs) and embraces three system risk controls of work scheduling, education and assurance.

ATSB comment:

The ATSB is satisfied that adherence to the policies and procedures detailed in FRMS 2 should reduce the likelihood of controllers being allocated excessive additional duty periods.

Last update 08 January 2014