The causes of pilot fatigue are more complex than previously thought and future fatigue risk management (FRM) is likely to be based less on simple duty/rest time quantities and ratios and more on qualitative assessments of actual sleep patterns and performance, says new research.
The findings by the University of South Australia’s Centre for Sleep Research (CSR) were presented last week in Paris at the International Aviation Safety Seminar (IASS) held by the Flight Safety Foundation, the International Air Transport Association and the International Federation of Airworthiness.
Working with airline crews, the CSR has confirmed that physical fatigue is closely related to the duration of work periods, or “hours of service (HOS)”, but mental fatigue is influenced more by other factors. In pilots, mental fatigue slows down decision-making and increases the likelihood of mistakes, says the CSR, but the onset of mental fatigue more closely reflects the timing, quality and duration of sleep a pilot obtains within rest periods than the length of time at work or the total time off.
The ability to obtain enough quality sleep depends on a large number of variables – including a pilot’s choice of how to use time off – so the CSR’s study proposes that airlines should make FRM an integral part of their safety management system, using a series of defined measures to assess and manage the level of risk.
Meanwhile, EasyJet presented the IASS with the results of a long-term, in-service fatigue study it is conducting with the UK Civil Aviation Authority that departed from the existing crew duty regulations, but gave better pilot performance results.
Pilots can manage fatigue up to a point, the study says, by being aware they are fatigued and focusing on counteracting its effects.