Fatigue management explained

Fatigue management involves operators and pilots taking steps to manage increasing levels of fatigue, so it doesn’t result in a safety risk.

Fatigue management is a shared responsibility between pilots, operators and us.

Having fatigue management policies and procedures makes sure that an organisation has mechanisms in place to identify and manage fatigue risks.

Fatigue management rules

New fatigue management rules (Civil Aviation Order 48.1 Instrument 2019) came into effect in July 2021. CAO 48.1 Amendment Instrument 2021, containing administrative edits and amendments due to the commencement of the flight operations rules, was published in November 2021.

The rules include obligations that flight crew license holders, air operator's certificate holders and Part 141 certificate holders must meet.

To comply with the fatigue rules in CAO 48.1, operators have the choice of using a prescriptive or flexible approach.

The approach you choose defines which of the Appendices to CAO 48.1 you should follow. We provide guidance about working to the fatigue rule appendices.

Prescriptive approach

For operators who would like to follow a prescriptive approach to fatigue management, there are 2 options.

Basic limits (Appendix 1 of CAO 48.1) set flight and duty time limitations without needing you to add risk management processes. However, you may find these limitations too restrictive.

We provide more guidance on how to adopt Appendix 1.

Enhanced fatigue management (Appendices 2 to 6 of CAO 48.1) allows greater flexibility with less restrictive flight and duty time limitations. This approach requires you to implement risk management processes, continuous monitoring processes and a training program for flight crew members.

Most air operator certificate holders will be able to meet the requirements of Appendices 2 to 6. See more information on how to apply Appendices 2 to 6.

If your operations fall slightly outside of the nominated Appendices (2 to 6), you may be able to request a 'minor variation'. See more information on how to apply Appendices 2 to 6.

Before making an application for approval of a minor variation consider the 

Minor variations policy for CAO 48.1 Instrument (2019) (PDF, 452.41 KB)

Flexible approach

Operating a Fatigue Risk Management System (FRMS) (Appendix 7 of CAO 48.1) gives you the most flexibility but is also the most complex fatigue risk management approach. It is a data-driven means of continuously monitoring and managing fatigue-related safety risks.

We provide more guidance on applying for an FRMS approval under Appendix 7.

Our approach to fatigue management

The International Civil Aviation Organization (ICAO) has established 4 basic scientific principles which should underpin fatigue management regulations:

  • the need for adequate sleep and the impact of extended time awake
  • the impact of sleep loss and recovery
  • daily rhythms in the ability to perform work driven by the brain's circadian clock
  • the influence of workload.

The 4 basic principles are reflected in CAO 48.1 Instrument 2019 and explained in more detail in CAAP 48-01 fatigue management for flight crew members (section 2.5).

Pilot obligations for managing fatigue risk

Pilots must take steps to manage fatigue risk. This includes deciding not to operate an aircraft if they feel that they are unfit because of fatigue, or likely to become so.

There are obligations for pilots to do this under CAO 48.1 Instrument 2019.

Each member of flight crew has licence conditions that prevent them operating an aircraft in the case of fatigue. Considering the circumstances of the flight, it is a condition for the licence holder that a reasonable person in the pilot’s position:

  • would consider that he or she is suffering from fatigue
  • is likely to suffer from fatigue which may significantly impair performance which affects the safety of the operation.

Before any flight duty period, a pilot employed by an operator must tell the operator:

  • any matter that a reasonable person in the pilot’s position would consider likely to negatively affect their ability to meet the operator’s fatigue risk management policies
  • that the pilot has achieved the limits and requirements of the appendix or appendices that the holder has chosen to apply.

Detailed guidance to meet these obligations is in CAAP 48-01 fatigue management for flight crew members.

Last updated:
30 May 2022
Online version available at: https://www.casa.gov.au//operations-safety-and-travel/safety-advice/fatigue-management/fatigue-management-explained
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