[Ref HK CAD 372, ICAO Annex 6, AVIA4004 Handout]
Fatigue is the physiological state of reduced mental or physical performance capability
Fatigue can result 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.
Types of fatigue
- Physical fatigue
– is defined as a state of reduced physical capacity. An individual can no longer continue to work because the involved physical sub-systems are not capable of performing the necessary functions.
- Cognitive fatigue
– is normally associated with stress and may be broadly defined as a generalized response to stress over time. The effects may reside as a psychological state within the individual and extend to affect performance.
Symptoms of fatigue include, restricted field of attention; slowed or impaired perception; decreased motivation; cognitive subjective feelings of fatigue and task aversion; and decreased performance in the form of irregularities in, speed, and accuracy.