Desynchronosis in Commercial Aviation

The technological breakthroughs of the 20th century have raised many questions regarding physiologic adaptation and environmental adversity. One such area of research involves high speed travel and its effect on biological rhythms. Multiple time zone transitions result in a phenomenon known as desynchronization, or "jetlag." This condition can have significant biological and behavioral consequences; it could even, possibly, represent a potential threat to aircrews involved in transmeridian flights.

The first pilot to experience jetlag was Wily Post. In 1933, he described various physiological alterations incurred while crossing time zones during global flight (Endo et al., 1978, p. 251). These changes resulted primarily from shifts in the body's normal circadian rhythms with respect to signals from the external environment (Winget et al., 1984, p. 1085).

Biological rhythms have been observed in practically all known species of animal. When these physiological fluctuations repeat themselves over a period of approximately 24 hours they are called circadian rhythms. Circadian oscillations can result either from environmental influences or selfsustained internal fluctuations. Considerable evidence suggests, however, that in the higher organisms the rhythms are mainly generated internally. For example, in mammals, body temperature rises and falls according to a regular daily schedule. These variations re

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w's job. Transoceanic flight demands a high level of functioning on the part of both pilots and flight attendants: the potential risks involved in such operations are considerable (Dement et al., 1986, p. B14). The research has revealed that alterations in aircrew sleep behavior can be strongly correlated with the direction of flight. In general, crewmembers experience less sleep problems after flying from east to west. These westbound travelers experience a circadian rhythm phase delay shift. After flying, for example, from North America to Japan, aircrews typically go to bed almost immediately upon arrival. Investigators have observed that during the first night of the layover people usually get as much sleep as at homebase. Additionally, this sleep tends to be of good quality: although there is an observed increase in the slow wave sleep, the westbound time zone transitions have no effect on REM sleep (Suvanto et al., 1990, p. 543). The only disturbance regularly experienced by these subjects is increased wakefulness during the second half of the night. In fact, the rate at which people were found to fall asleep was actually higher than that measured as a baseline level. Despite such observations, these subjects a
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Approximate Word count = 2012
Approximate Pages = 8 (250 words per page)

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