Analysis of in-flight spatial disorientation among military pilots in Taiwan

Abstract

Background: In-flight spatial disorientation (SD) is a predominant threat to flight safety in aviation. This study was conducted to understand the prevalence, severity, and frequency of in-flight SD among military pilots in Taiwan. Methods: A survey was conducted to collect tri-service pilots' experiences of SD during flight. Participants completed anonymous SD questionnaires during refresher physiology training. There were 486 questionnaires delivered to trainees and the completion rate was 97.1% (n = 472). All data were processed using SPSS version 24 software (IBM, Armonk, NY, USA). Results: Of the 472 participants, the average age of the pilots was 36.7 so 7.3 years and 97.7% were male. About 80% of participants experienced in-flight SD events. There was a significant difference between prevalence of SD in fighter (87.0%), trainer (89.8%), transporter (70.6%), and helicopter (66.7%) pilots (P < 0.001). Less than 10% of the events were severe, and there was no obvious variation between aircraft types (P = 0.126). Pilots were sensitive to SD in clouds and under low visibility. Over 70% of pilots experienced visual illusions, especially loss of horizon during bad weather (45.1%), followed by leans (44.5%), false horizon (44.1%), false sense in clouds (39.6%), Coriolis illusion (25.0%), and confusion on entry to instrument meteorological conditions (25.0%). Conclusions: Our survey showed that SD is a common physiological problem among military pilots, who were easily disoriented by in-flight SD without visual cues. Visual illusion was relatively more frequent, especially for trainer and fighter pilots.