Fatigue Risk Management System

ICAO (2011) defines a Fatigue Risk Management System as:

"A data-driven means of continuously monitoring and maintaining fatigue related safety risks, based upon scientific principles and knowledge as well as operational experience that aims to ensure relevant personnel are performing at adequate levels of alertness".

Fatigue is one of the greatest threats to flight and cabin crew in the aviation industry. Fatiguing environments, long work hours and time-zone changes all compound resulting in an increased risk of fatigue. For more on fatigue, see fatigue.

Traditionally, the aviation industry has taken a regulatory approach to fatigue prevention through flight and duty limitations. This is done by limiting the amount of hours a crew can work and then specifying the minimum rest time they require. Such regulations have remained relatively unchanged since the 1950's (ALPA, 2008). A FRMS takes a more scientific approach to regulating crew rest, recognising the requirement that crew be well rested before work and that adequate periods of rest are provided in flight and, following duties (ALPA, 2008).

In the later part of the 20th century, research provided evidence that there were other causes to fatigue. The main contributors to fatigue in flight crews are:

  • Lack of adequate sleep, not just rest and its impact in maintaining all aspects of waking mechanisms.
  • Daily body rhythms, known as circadian rhythms, impact the quality of sleep and also influence performance when awake.

A fatigue risk management system allows operators to manipulate flight and duty limitations whilst taking into account the above effects. Fatigue models are used to proactively manage fatigue. Safety benefits include increased employee alertness, better work life balance amongst crews and a reduction in absenteeism due to fatigue (Hambour, 2011). In addition to this, FRMS can provide increased productivity and flexibility in rostering.

Several examples of successful fatigue risk management systems are in place today (Cabon et al., n.d.):

  • Singapore Airlines introduced a FRMS in 2003 after commencement of ultra long haul (ULH) flights between Singapore and New York. The company was allowed to operate these flights as a result of scientific recommendations based on biomathmatical modelling.
  • easyJet in the United Kingdom was the first major airline to be issued a dispensation from traditional flight and duty limitations (FTL) after trialing a new roster based on FRMS principles. The new roster which features a 5/2/5/4 (5 early starts, 2 days off, 5 late starts, 4 days off) programme was proven to be significantly less fatiguing than the traditional 6/3 roster (3 early starts, 3 late starts and 3 days off).
  • New Zealand has the longest experience with the development of FRMS. In 1995, Civil Aviation Authority regulations were changed to allow operators to use either a traditional FTL scheme or an approved variation on that scheme. Organisations wishing to employ the later had to take into account additional factors that might cause fatigue.

In 2008, ICAO first introduced FRMS to annex 6 and identified the need for detailed guidance on how authorities should implement and oversee FRMS operations (ICAO, 2011). The task force assigned to this project is due to meet again in the first week of September 2011 to further develop these concepts.


ICAO (2011). Fatigue Risk Management Systems - Implementation Guide for Operators. http://www2.icao.int/en/FRMS2011/Documents/Reference%20Documents/FRMS%20Guide%20FINAL%20Print%2007.14.11.pdf, July 2011.
ALPA (2008). ALPA White Paper - Fatigue Risk Management Systems. http://www.alpa.org/portals/alpa/pressroom/inthecockpit/FatigueRiskMSWP_6-2008.pdf, June 2008.
Hambour, L (2011). A Fatigue Risk Management System - The Way Forward? http://www.skybrary.aero/bookshelf/books/1525.pdf, June 2011.
Cabon, P., Mollard, R., Debouck, F., Chaudron, L., Grau, J., Deharvengt, S. (n.d.). From Flight Time Limitations to Fatigue Risk Management Systems. http://www.resilience-engineering.org/RE3/papers/Cabon_Mollard_Debouck_Chaudron_Grau_Deharvengt_text.pdf, n.d.

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