Flight hours within 7 days and risk of fatigue on the civilian pilots in Indonesia

Background: In aviation world, fatigue may cause incapacitation among pilot which can lead to aircraft accidents. Flight hours is believed to be one of the factors related to the risk of fatigue. The purpose of this study is to identify relationship between flight hours in seven day and other factors to the risk of fatigue among civilian pilot in Indonesia.Methods: A cross sectional study with consecutive sampling was conducted among civilian pilots who attended medical check-up at Aviation Medical Center in Jakarta on June 2016. Demographic characteristics, employment related factors, habits and flight hours were obtained through questionnaire and interviews. Fatigue data were obtained through fatigue self-questionnaire form and measured with Fatigue Severity Scale which had been validated. Fatigue was categorized into non-fatigue (FSS score <36) and fatigue (FSS score ≥36). Relative risk was computed using Cox regression with a constant time.Results: This study included 542 pilots among which 50.2% had fatigue. The subjects who have flight hours >30 hours/week compared to ≤30 hours/week, had 1.37-fold higher risk of fatigue [adjusted relative risk [RRa=1.37; CI=1.14-1.65; p=0.001]. The subject with ATPL license compared to CPL license had 1.28-fold higher risk of fatigue [RRa=1.31; CI=1.11-1.54; p=0.001). Furthermore, subjects who have appropriate exercise had 32% lower risk of fatigue (RRa=0.68; CI= 0.39-1.19; p=0.094).Conclusions: Civilian pilots in Indonesia who had more than 30 hours flight time in 7 days and ATPL type pilots have an increased risk of fatigue. Appropriate exercise decreased the risk of fatigue.Keywords: fatigue, flight hours. civilian pilots. Indonesi