G-Induced Alterations of Consciousness in UK Military Aviation

Despite multiple risk mitigations, the adverse effects of +Gz acceleration on cerebral circulation continue to cause military aircraft incidents. A previous survey of Royal Air Force aircrew in 2012 reported that 37.2% had experienced at least one episode of G-induced alteration of consciousness. The aim of the present study was to determine whether the introduction of updated centrifuge training and improved countermeasures in training aircraft has reduced the prevalence of these incidents.

An anonymous online survey of all UK Armed Forces pilots was carried out in 2023 to reassess the prevalence of G-induced alterations of consciousness and to investigate perceptions of G-related risk factors and mitigations in pilots exposed to the high-G environment.

Responses were received from 403 pilots, with a response rate of 11.9%. At least one incident of G-induced alteration of consciousness was reported by 21.6% of pilots. Frontline jet pilots reported a higher proportion of incidents compared to previous surveys, with more recent incidents involving the Eurofighter Typhoon than any other aircraft type (29.0% from 2015-2023, N = 38). Recency of +Gz exposure was rated as the most important factor affecting the risk of G-induced incidents.

An overall reduction in prevalence of G-induced alteration of consciousness incidents was observed, with frontline jet pilots reporting a higher proportion of incidents over time. The reported importance of high-G recency as a risk factor suggests that additional risk assessment for the G-layoff effect may be beneficial for UK frontline jet pilots. Jones M-L, Britton JK, Green NDC, Pollock RD. G-induced alterations of consciousness in UK military aviation. Aerosp Med Hum Perform. 2026; 97(4):257-263.