submission - Independent Pilots Association

Scientific support:
(a) Scheduling the Protected Time Period for the salr¡e time each day
Time-of-day / Circadian Physiology Afiects Sleep and \{aking Performancr -
. . . Tinre-of-day or circadian effects are important considerations in addressing 24
hour operational requirements because circadian rhythms do not adjust rapidly to
change.
. . . Thus, circadian disruption can lead to acute sleep deficits, cumulative sleep
loss, decreases in performance and alertness, and va¡ious health problems . . .
Therefore, circadian stability is another consideration in duty and rest scheduling.
NASA Feconunends a sleep opportunity that is predictable (24 hours notice
re,coÍ[nended), does not vary rnore than 3 hours on subsequent days to ensure circadian
srability, and is protected from intem¡ption. @mphasis added-)
NASA TM, Il .3, p. 34;12.6.2, p. 8.
Conclusion -
hour cycle.
Banelle Report, p.28.
Remarks of Dr. Dement
Reserve assignments should anernpt to maintain a consistent 24
Q: Dr. Dernent, there's one area that we really haven't touched upon at this point and
I don't want to miss. These are questions re_sarding the maintenance of cr¡cadian
stability. [n your opinion, why is maintaining circadian stability so important?
A: Well because usuall.""... and b¡' that you mean your sleep opportunities and vour
wake oppomrnities Íue in that period of stability, then you have the best sleep and
the best walie. If you get out of that cycle, then both sleep and wake will be
impaired.
Q: What happens to the body as you change a person's cycle?
A: All sorts of things happen, but the major thing of course is that you are now trving
to sleep when the body wants to be awake and you're trying to be awake when the
body wants to be asleep because you left the circadian stability that you talked
about.
Appendix D,pp. líl7.
t8