《Fatigue-is-a-risk-factor-for-flight-performance》由会员分享，可在线阅读，更多相关《Fatigue-is-a-risk-factor-for-flight-performance（11页珍藏版）》请在金锄头文库上搜索。
1、 Fatigue is a risk factor for flight performance and safety in commercial aviation. In US commercial avi-ation, to help to curb fatigue, the maximum duration of flight duty periods is regulated based on the scheduled start time and the number of flight segments to be flown. There is scientific suppo
2、rt for regu-lating maximum duty duration based on scheduled start time; fatigue is well established to be modulated by circadian rhythms. However, it has not been established scientifically whether the number of flight segments, per se, affects fatigue.To address this science gap, we conducted a ran
3、domized, counterbalanced, cross-over study with 24 active-duty regional airline pilots. Objective and subjective fatigue was compared between a 9-hour duty day with multiple take-offs and landings versus a duty day of equal duration with a single take-off and landing. To standardize experimental con
4、ditions and isolate the fatiguing effect of the number of segments flown, the entire duty schedules were carried out in a high-fidelity, moving-base, full-flight, regional jet flight simulator. Steps were taken to maintain operational realism, including simulated air-plane inspections and acceptance
5、 checks, use of realistic dispatch releases and airport charts, real-world air traffic control interactions, etc. During each of the two duty days, 10 fatigue test bouts were adminis-tered, which included a 10-minute Psychomotor Vigilance Test (PVT) assessment of objective fatigue and SamnPerelli (S
6、P) and Karolinska Sleepiness Scale (KSS) assessments of subjective sleepiness/fatigue.Results showed a greater build-up of objective and subjective fatigue in the multi-segment duty day than in the single-segment duty day. With duty start time and duration and other variables that could impact fatig
7、ue levels held constant, the greater build-up of fatigue in the multi-segment duty day was attributable specifically to the difference in the number of flight segments flown. Compared to findings in previously published laboratory studies of simulated night shifts and nighttime sleep deprivation, th
8、e magnitude of the fatiguing effect of the multiple take-offs and landings was modest. Ratings of flight performance were not significantly reduced for the simulated multi-segment duty day.The US duty and flight time regulations for commercial aviation shorten the maximum duty duration in multi-segm
9、ent operations by up to 25% depending on the duty start time. The present results represent an important first step in understanding fatigue in multi-segment operations, and provide support for the number of flight segments as a relevant factor in regulating maximum duty duration. Nonetheless, based
10、 on our fatigue results, a more moderate reduction in maximum duty duration as a function of the number of flight segments might be considered. However, further research is needed to include investigation of flight safety, and to extend our findings to nighttime operations.Passenger-carrying domesti
11、c flights in US commercial aviation were governed, until recently, by duty and flight time regulations stipulated in Title 14 Code of Federal Regulations (CFR) Part 121. In unaugmented flight operations (comprising only the minimum number of pilots required to operate the airplane), the regulations
12、restricted pilot duty time to a maximum of 16 h and flight time to a maximum of 8 h per duty period. These requirements were fixed regardless of the number of flight segments (i.e., number of take-offs and landings) within the duty period. New duty and flight time regulations for US domestic operati
13、ons, based in part on the extant science of fatigue and safety, took effect on January 4, 2014. In these new regulations, included in Title 14 CFR Part 117, duty duration is limited as a function of duty start time and as a function of the number of flight segments in the duty period.In the new regu
14、lations, a duty period starting between 05:00 and 06:00, for example, is limited to 12 h for between 1 and 4 scheduled flight segments, dropping stepwise to 10.5 h (a 12.5% reduction) for 7 flight segments or more. Similarly, a duty period starting between 07:00 and 12:00 is limited to 14 h for 1 or
15、 2 scheduled flight seg-ments, dropping stepwise to 11.5 h (a 17.9% reduction) for 7 flight segments or more. The maximum duration of the duty period in unaugmented operations varies between 9 h and 14 h depending on the duty start time. The reduction in the maximum duration of the duty period as a
16、function of the number of scheduled flight segments ranges from 0% to 25% depending on the duty start time.The relevance of duty start time for limiting duty duration is corroborated by established fatigue science (Roach et al., 2012; Vejvoda et al., 2014). Endogenous circadian rhythmicity produces daytime and nighttime peaks and troughs in subjective alertness and cognitive performance (Kerkhof and Van Dongen, 1996; Monk et al., 1997). Additionally, an endogenous sleep/wak
