It’s not just the amount of rest, but also the timing of rest

Do pilots get enough rest?:

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The federal rules on pilot duty hours and rest periods aren’t the most comprehensible of reads.
One rule allows airlines to schedule pilots to fly for eight hours or less during a 24-hour period without a “rest period during those eight hours.” Another gives pilots who fly for more than eight hours in a 24-hour stretch a break of at least twice the number of hours flown, either “at or before the end of” the eight hours. Pilots who fly more than eight hours during a 24-hour period must receive 18 hours of rest before being assigned any other duties.
“Those rules underwent a modest updating in 1988,” Mazor said. “Then there was a proposal 10 years ago that was far from satisfactory to begin with, and we haven’t even gotten that.”
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Mark Rosekind, a psychologist and president of Alertness Solutions in Cupertino, Calif., took part in that 1995 effort to rewrite the FAA flight crew duty and rest rules. At the time, he was a principal investigator with NASA’s Fatigue Countermeasures Program. Today, in addition to running his consulting company, he teaches a course on sleep, fatigue and circadian factors – the internal “clock” that affects numerous body functions – for the NTSB Academy in Ashburn, Va.
“Current FAA regulations were written in 1937 and have not been rewritten in any dramatic way since,” Rosekind said. “In 1937, jets didn’t exist. Today we have airplanes that have more range, travel into more time zones and do more short-haul routes. The regulations don’t reflect the industry today or changes in the science of sleep and circadian rhythms in 50 years.”
The FAA’s 1995 proposal called for a decrease in consecutive duty hours – which includes duties on the ground – from 16 to 14 hours, but an increase in maximum flying time to 10 hours during that 14-hour span. An FAA spokeswoman said the proposed rules drew more than 2,000 comments, mostly in opposition.
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