Spatial orientation in aviation: visual contributions.

Misjudgment of spatial orientation is reported to be an important factor in a substantial proportion of aviation accidents. The likelihood of such misjudgment is particularly high when there are conflicting interactions between labyrinthine and visual signals. In a manoeuvering aircraft, visual information is often a crucial factor in the pilot's ability to judge the aircraft's altitude and position with respect to external and terrain features. A body of research evidence supports the following conceptual framework. (1) The human visual system processes a limited number of visual dimensions almost independently of each other (for example, colour, luminance, spatial frequency, orientation, changing size, motion in depth, time to contact). (2) Each of these selective sensitivities shows considerable intersubject variability. (3) Intersubject variability is far from perfectly correlated across the set of selective sensitivities. This paper discusses the relevance of this framework for predicting, first the specific situations in which visual judgments are most likely to occur and, second, which individual pilots are most likely to make the visual misjudgments.