Impact of ageing on Air Traffic Controllers sleep and fatigue: a field study

This study aims to assess the impact of ageing on air traffic controllers (ATCOs) in the context of the increase of the retirement age in Switzerland. A data collection campaign was conducted over 15 consecutive days. During this campaign, participants completed questionnaires alongside with sleep logs and providing fatigue ratings at start and the end of each duty. A total of 155 ATCOs participated in this data collection. Findings reveal that night shifts induce higher levels of fatigue at the beginning of duty compared to early shifts, with this effect becoming more pronounced as ATCOs age. Older ATCOs (50+) exhibit higher fatigue levels at the start of duty compared to those under 50. When interacting with consecutive duty factors, age appears to have a somewhat protective effect on fatigue at the beginning of duty. Fatigue levels increase less rapidly for those aged 50 and over compared to those under 30 between the 3rd and 4th consecutive day, suggesting that older ATCOs have developed specific fatigue management strategies. Furthermore, age exacerbates fatigue when interacting with workload during peak traffic hours, amplifying the effects of workload on fatigue, particularly for the 50+ age group. Additionally, age interacts with sleep quality before duty: higher sleep quality leads to decreased fatigue at the end of duty, especially for older ATCOs. This implies that ageing increases sensitivity to sleep quality. From this research, several recommendations have been produced to mitigate the effects of working condition on sleep and fatigue of older ATCOs.