The Opto-Kinetic Cervical Reflex During Formation Flight

Jennie J. Gallimore, Ph.D., Frederick R. Patterson, Ph.D., Nathan G. Brannon, M.S., and Joseph P. Nalepka, M.S.
Aviat Space Environ Med 2000; 71:812-21

Abstract

Background: 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. Hypotheses: 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. Methods: 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°, 60° and 100° 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 significantly affect the OKCR. Conclusions: 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.

Keywords: formation flight, field of view, opto-kinetic cervical reflex, visual cues.

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Table of Contents for Volume 71, Number 8 of the ASME journal.