Actigraphy-Driven Biomathematical Fatigue Modeling in British Military Rotary-Wing Pilots

INTRODUCTION: A study of fatigue in British military rotary-wing pilots was conducted to determine the utility of actigraphy-driven fatigue modeling in the military rotary-wing environment.

METHODS: A total of 48 pilots were recruited across the 3 military services of the United Kingdom. Objective fatigue was predicted using wearable actigraphy and the Sleep Activity Fatigue Task Effectiveness (SAFTE) fatigue model. Subjective data were collected from daily questionnaires completed by the study subjects, including an assessment of their own fatigue level using Samn-Perelli Scale scores. The relationship between these two data sets was then assessed with correlation and linear regression modeling.

RESULTS: There were 38 men and 2 women recruited. The mean age was 36.4 yr (standard deviation ± 6.5, range 26–52 yr). In total, 200 flights were undertaken, with a mean flight time of 156 min (± 77.1, range 15–480); the mean landing time of these flights was 18:45 (range 11:00–02:30). The data included 37 d of pilots deployed on exercise. SAFTE scores were shown to decline for night flying, especially if landing after 22:00. With increasing subjective levels of fatigue, the relationship between SAFTE and Samn-Perelli Scale scores in subjects weakened.

DISCUSSION: Actigraphy-driven modeling has a role in specific aspects of military rotary-wing aviation. Consideration should be given to its use in specific scenarios, including night-flying and flights undertaken when deployed on exercise.

Pelham A, Van Tongeren M, Arnold H, Cocco P. Actigraphy-driven biomathematical fatigue modeling in British military rotary-wing pilots. Aerosp Med Hum Perform. 2025; 96(3):206–211.