ABSTRACT
The objective of this research was to extend and validate a model of aviation display clutter including objective measures of visual display properties and pilot subjective assessments of display characteristics, as a basis for predicting pilot perceptions of clutter and flight performance. The focus of this study was on use of a Head-Down Display (HDD) in a vertical takeoff and landing (VTOL) aircraft simulator. Sixteen pilots flew a series of instrument approaches including an ILS (instrument landing system) segment to a hover phase involving vertical descent to a landing decision point. The HDD consisted of a monochrome primary flight display and navigation display along with combinations of advanced instrumentation, a highway-in-the-sky tunnel, a synthetic vision terrain depiction, and an infrared camera-based enhanced vision display. Pilots subjectively evaluated each display during the ILS segment and after completing the vertical descent on six characteristics (information
redundancy, colorfulness, salience, dynamics, variability, and density) and for overall clutter. The luminance, contrast between information elements, occlusion of information elements, and global density of each display were also measured. Flight performance was measured as the root mean square error (RMSE) of deviations from the desired flight path. A factor analysis revealed ratings on the six display characteristics loaded on three latent variables comprising similarity, dynamics, and intensity. The three factors accounted for 72-76% of the variance in pilot ratings of overall display cl utter. The measures of display properties accounted for 16-43% of the variance in clutter ratings. Regression models including both the latent variables and measures of display properties accounted for a small proportion of glide slope deviations under certain conditions as well as deviations in groundspeed and distance from touchdown point. The findings suggest the integrated model of display clutter, based on pilot ratings and visual properties, has utility across various display and aircraft types.
