The opto-kinetic cervical reflex during formation flight

Weather formation flight is a difficult task prone to episodes of spatial disorientation. Therefore, investigation of sensory reflexes under these conditions is critical. Recent studies have shown that the opto-kinetic cervical reflex (OKCR) occurs during VMC flight conditions and serves to establish the horizon retinal image as a stabilized primary visual-spatial cue. The purpose of this research was to investigate the OKCR and field of view (FOV) during formation flight under VMC and IMC.

During 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 OKCR-induced head movement.

There were 2 experiments conducted in which a total of 26 pilots completed simulated flight tasks in a stationary dome. Head tilt was examined as a function of aircraft bank with unrestricted FOV in Experiment I. Experiment II examined head tilt under three FOV conditions (40 degrees , 60 degrees and 100 approximately circular).

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 significantly affect the OKCR.

Pilots exhibit the OKCR during Formation and Solo VMC tasks. However, the OKCR is reduced when compared with low level navigation tasks, indicating a difference in the visual cues between tasks. Pilots do not exhibit OKCR during IMC flight; therefore, the OKCR will have an impact on formation flights in and out of clouds leading to sensory conflicts caused by repeated realignment of visual and vestibular systems.