Investigation on cumulative psychophysiological effects of short-haul flight crew members - Part II: Results

Abstract

Background: The focus of scientific explorations concerning fatigue and workload of flying staff in civil aviation was predominantly put in monotony, jet-leg aspects and phase shifts during and after long-range flights. The aeronautical task of flight crews on short-haul operations was hardly aeromedically examined. The work area on short-haul operations, however, is subjected to main constrains differing from those in long-haul operations in crucial points. High workload related to the large number of takeoffs and landings due to several legs per day, irregular hours of work and pressure of time during a duty day may lead to fatigue symptoms. In cooperation with Lufthansa German Airlines, an investigation on cumulative psychological and psycho-physiological effects of the work environment on human factors of flight crews was launched in 2003 (methods in detail see Vejvoda et al. part I). Results: During the study period no cumulative effects are ascertained in subjective sleep quality and sleep need. However, since commencement of the study, fatigue and strain increase within the term of investigation. These effects are significantly higher at the end of flight duties than at the days off (Z= -11.507, p = .000). Performance in the Psychomotor Vigilance Task (PVT) according to Dinges and Powell (1985) significantly decreases at the end of the flights over the two months (F= (55,720) 4.931, p =.000). Altogether, in respect of cumulative effects no critical long-term effects are observed. However, under the conditions investigated acute significant effects on fatigue and workload can be detected in-flight. The level of increasing fatigue and workload is affected by a combined effect of length of duty, time of awakening and the number of sectors flown in a day. Discussion: Data provide current effects on sleep-wake behaviour, fatigue and workload of short-haul cockpit crew members during duty days within the period of eight weeks. As a result of these findings recommendations and a broader scientific database could be established in the context of discussing duty scheduling in commercial aviation at European level.