submission - Independent Pilots Association

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(2) If the tlight crewmember is given a flight assignment for any pan of the
period of 0200 to 0600 hours, any suchflight assignment must be
scheduled to be completed within 14 houn afier the end of the preceding
Protected Time Perbd- The operator wilh the concunence of the
a-dminßtrator and the pilot group may designale any $hour periodfor
all operutions betveen 0000-06M houn in place of 0200-06(X) houn.
Scientific zupport:
(c ) Reducing the Rescrve Availability Period by two hours during Back-Side-Of-The-
Clock Operations (0200 - 0600)
Offduty perid (folbwing standard füght duty periods during window of
circadian low) - Extensive scientific research, including aviation dat4
dernonstrue that rnaintaining wakefulness during the window of circadian low is
associated with higher levels of performance-impairing fatigue than during
daytime wakefulness. . . .
Ileñnition: "vvindow of circadian low" - The window of circadian lon' is best
estimated by the hours between 020O and 06OO for individuals adapted to a usual
day-wake/night-sleep schedule. This estimate of the widow is calculated from
scientifrc data on the circadian low of performance, alenness, subjectiye repon
(i.e. peak fatigue), and body temperan¡re. . . .
NASA TM,1I2.1.4.2.3.2. PP. 5-6.
The ingredient of day versus night long-haul flights ralses a second concern. the
time-of-da,v departure. Because sleepiness and fatigue are strongly related to
circadian rhythmicity, they should not be controlled by regulations. which ignore
time-of-day in favor of elapsed time. . . . For the sake of efficiency and safety. it is
incumbent upon regulatory authorities to include time-of-day as a factor in
designing flight crew duty and rest hlrutattons.
R. Curtis Graeber, et al., Aircrew'Sleep and Fatigue in l-ong-Haul Flight Operarions,
. Tokyo. Japan (Octoþr 2G29,1987), P. 13.
Back of the.Clock Operations, Circadian Rhythm and Performancc
There is a substantial body of research that shows decreased performance during
night shifts ¿Ls comp¿ìred with day shifts. The reasons for this decreased
performance include:
o Circadian pressure to sleep when the individual is attempting to work.
. Circadian pressure to be awake when the individual is attempting to sleep.
o Time since awake may be substantial if the individual is up all day before
reporting for the night shift.
o Cumulative sleep debt increase throughout the shift.
Research conducted by Monk et al. ( 1989) indicates that subjective alertness is
under the control of the endogenous circadian pacemaker and one's sleep-wake
cycle (time since awake). r#hen tirne since awake is long and coincides with the
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