submission - Independent Pilots Association

(2) If the Ílight crewmember is given a flight assígnment for any part of the
period of 0200 to 0600 hours, any such flight assignment must be
scheduled to be completed within 14 hours afier the end of the preceding
Protected Time Period. The operator with the concurrence of the
administrator and the pilot group may designate any 4-hour period for
all operations between 0000-0600 hours in plnce of 0200-0600 hours.
Scientific support:
(c ) Reducing the Reserve Availability Period by two hours during Back-Side-Of-The-
Clock Operations (0200 - 0600)
Otr-duty period (following standard flight duty periods during window of
circadian low) - Extensive scientific research, including aviation data,
demonstrate that maintaining wakefulness during the window of circadian low is
associated with higher levels of performance-impairing fatigue than during
daytime wakefulness. . . .
Definition: 'fuindow of circadian low" - The window of circadian low is best
estimated by the hours between 0200 and 0600 for individuals adapted to a usual
day-wake/night-sleep schedule. This estimate of the widow is calculated from
scientific data on the circadian low of performance, alertness, subjective report
(i.e. peak fatigue), and body temPerature. . . .
NASA TM.1l1t 2.t.4,2.3.2, pp. 5-6.
' The ingredient of day versus night long-haul flights raises a second concern, the
time qfuþ¡þ,parture. Because sleepiness and fatigue are strongly related to
circadiãiì rhythmicity, they should not be controlled by regulations, which ignore
time-of-day in favor of elapsed time. . . . For the sake of efhciency and safety, it is
incumbent upon regulatory authorities to include úme-of-day as a factor in
designing flight crew duty and rest limitations.
R. Curtis Graeber, et al., Aircrew Sleep and Fatigue in Long-Haul Flight Operatiorts,
Tokyo, Japan (October 26-29, 1987), p. 13.
Back of the Clock Operations, Circadian Rhythm and Performance
There is a substantial body of resea¡ch that shows decreased performance during
night shifts as compared with day shifts. The reasons for this decreased
performance include:
a Circadian pressure to sleep when the individual is attempting to work.
a 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-u'ake
cycle (time since auake). When time since auake is long and coincides with the
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