Due to the increasing mobility of today's society, the pressure of competition for airline companies and the development of new models of aircraft for long-distance flights, irregular working hours (including night-work and time zone flights) are part of the normal working environment of cabin crews. In order to be able to determine the work load and strain on cabin crews, aero-medical examinations were conducted with the flight crew of the flight route Frankfurt (Main) - San Francisco - Frankfurt (Main) (9 time zones). With round trips on the North Atlantic route, the outgoing flight takes place by day and the return flight by night.
During the period between June 1997 and June 1998, 44 flight attendants aged 24 to 38 years (average age of 31.26 years, sd=4.00 years) were examined. The duration of the individual examinations included three days before the round trip, the round trip itself and three days after the round trip. The ECG was recorded continuously for the determination of stress and strain. The blood pressure was measured hourly during the flights on one control day. The cortisol concentration in the saliva was registered - as far as possible - hourly during the waking period. Questionnaires concerning the current state of wakefulness / fatigue and work load were also filled in every hour. Duration and quality of sleep were recorded using sleep logs and measurements of activity. The body temperature was measured before and after the round trip in order to register the circadian rhythm.
The results of the study show that under the conditions examined, (1) differences between the control data and the data measured during and after the flights do exist, (2) the subjective perception of the flight attendants show differences between outgoing and return flights, (3) the physiological measured data do not show distinctive differences between outgoing and return flights, (4) the data of the individual service classes differ, (5) no extreme changes in circadian rhythm occur, (6) the sleep-waking-pattern shows the development typical for this kind of duty (7) fatigue levels rise significantly during specific sections of the flight, (8) stress and strain are particularly high in the economy class, leading to a recommendation of higher numbers of crew members in this area.
This study adds to the evaluation of working and environmental conditions on a transmeridian round trip.
It may serve as a basis for discussions in Europe about the harmonization of flight duty and rest times of cabin crew.
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