(NaturalNews) Recent analyses of the sleep, work and activity patterns of airline pilots show that many are flying under unsafe levels of exhaustion. Most recently, Simon Bennett of the University of Leicester, England, has raised concerns about the European Aviation Safety Agency's (EASA) proposed new flight-time limitations (FTLs) for pilots, saying that they have been developed with no attention to recent scientific findings.
"Regulations made without reference to scientific knowledge or social context are dangerous," Bennett said. "EASA's proposed FTLs take little account of the latest sleep research and no account of the pilot lifestyle as described in my own research. Passenger safety is threatened."
The main problem, Bennett notes, is that the proposed FTLs regulate only the amount of time that a pilot may spend flying, disregarding other factors that may influence pilot exhaustion. For example, Bennett's surveys of pilots have shown that nearly 50 percent have a commute of more than an hour, yet FTLs disregard the effect that this extra travel time has on pilot fatigue.
"FTLs take no account of the pilot lifestyle," Bennett said. "No account is taken of prior wakefulness, the duration and quality of sleep or commuting. FTLs are dissociated from the realities of life -- despite the fact that those realities affect performance."
More than 20 percent of all pilots that Bennett surveyed said that they had been awake for 28 or more hours at the end of a single shift.
"Research proves that judgment is seriously impaired after 18 hours of wakefulness," Bennett said. "How well do you think you could drive after being awake for 18 hours?
Disrupted Sleep Cycles
In a 2012 study published in Current Directions in Psychological Science, psychologist John A Caldwell of fatigue assessment firm Fatigue Science analyzed the different factors that contribute to pilot fatigue. In addition to simple lack of sleep, Caldwell notes that the interruption of pilots' natural sleep-wake cycles also contributes to dangerous sleepiness and fatigue. Yet these cycles are regularly disrupted during day-to-day pilot work by factors such as long shifts, nighttime flights, and the crossing of multiple time zones in a short period.
"Fatigue-related risks increase substantially when (a) the waking period is longer than 16 hours, (b) the preduty sleep period is shorter than 6 hours, or (c) the work period occurs during the pilot's usual sleep hours," Caldwell wrote.
The focus on FTLs "seems to be a function of convenience rather than science," he wrote. To truly correct the problem of dangerous pilot fatigue, airlines need to implement science-based measures such as educating crew members on sleep hygiene, allowing onboard cockpit napping, and the use of sleep-tracking technologies.
"As a society, we must come to grips with the fact that the average adult needs 7-9 hours of sleep every single day," Caldwell said. "And there is no amount of willpower, professionalism, training, or money that will prevent the performance losses associated with the failure to routinely acquire sufficient sleep."