Fatigue is defined as a physiological state of reduced mental or physical performance capability resulting from sleep loss or extended wakefulness, circadian phase, or workload (mental and/or physical activity) that can impair a crew member’s alertness and ability to safely operate an aircraft or perform safety-related duties.
A fatigue risk management system (FRMS) is defined as a data-driven means of continuously monitoring and managing 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 management requirements applicable to operators are addressed in Annex 6 — Operation of Aircraft, Part I — International Commercial Air Transport — Aeroplanes. They require States to put in place regulations for managing fatigue based on scientific principles, either through mandatory prescriptive regulations on flight time, flight duty period, duty period and rest period limitations or optional fatigue risk management systems (FRMS) regulations. These provisions are applicable to flight and cabin crew.
More information on fatigue risk management can be found in the following documents:
Fatigue Risk Management Systems Manual for Regulators (Doc 9966);
ICAO-IATA-IFALPA FRMS Implementation Guide for Operators;
Cabin Crew Safety Training Manual (Doc 10002)
