The opto-kinetic cervical reflex during formation flight

Background: Weather formation flight is a difficult task prone to episodes of spatial disorientation. Therefore, investigation of sensory reflexes und er these conditions is critical. Recent studies have shown that the opto-ki netic cervical reflex (OKCR) occurs during VMC flight conditions and serves to establish the horizon retinal image as a stabilized primary visual-spat ial cue. The purpose of this research was to investigate the OKCR and field of view (FOV) during formation flight under VMC and IMC. Hypotheses: Durin g VMC tasks pilots will align their heads with the visible horizon, but not under IMC. As FOV is decreased, there will be a significant reduction in O KCR-induced head movement. Methods: There were 2 experiments conducted in w hich a total of 26 pilots completed simulated flight tasks in a stationary dome. Head tilt was examined as a function of aircraft bank with unrestrict ed FOV in Experiment I. Experiment II examined head tilt under three FOV co nditions (40 degrees, 60 degrees and 100 degrees circular). Results: During VMC maneuvers pilots exhibited significant OKCR. There were no differences in head tilt between Solo Figure 8 and Formation Figure 8 VMC conditions. Pilots did not tilt their heads under IMC Formation Flight. FOV did not sig nificantly affect the OKCR. Conclusions: Pilots exhibit the OKCR during For mation and Solo VMC tasks. However, the OKCR is reduced when compared with low level navigation tasks, indicating a difference in the visual cues betw een tasks. Pilots do not exhibit OKCR during IMC flight; therefore, the OKC R will have an impact on formation Rights in and out of clouds leading to s ensory conflicts caused by repeated realignment of visual and vestibular sy stems.