An Investigation into Landing Approach Visual Illusions

Abstract

This experiment was designed to examine aspects of human visual perception during approaches to a runway. The runway width illusion has commonly been reported to contribute to the dangerous tendency of pilots to fly low approaches to runways that are wide and high approaches to runways that are narrow. Attempts to prevent the runway width illusion have not attempted to identify the ideal location for an indicator of altitude. Thus the present experiment examined the effect of varying runway width and manipulated scenes in order to determine whether the runway width illusion was present and where participants were focusing their attention in the scenes. Thirty-two non-pilot participants and 3 pilots took part in the experiment and viewed static and dynamic scenes of runways that were narrow (30.48m), medium (60.96m) or wide (91.44m) at one of three viewing heights low (30.48m), medium (45.72m) or high (60.96m). After viewing scenes, participants were required to estimate their altitude and aim-point. The results of this experiment revealed that participants were fairly inaccurate at estimating altitude and were inclined to overestimate aim-point, however the data also indicated that there was a robust runway width illusion that was present across static and dynamic trials and in both altitude and aim-point data. The standard marking on the runway in an attempt to prevent the runway width illusion was not effective at preventing incorrect altitude estimations but did assist participants to estimate aim-point. It was also found that the objects that participants' most commonly reported using to estimate altitude in the visual scene were located in the lower segment of the scenes.