HELMET MOUNTED DISPLAY SYMBOLOGY INTEGRATION RESEARCH

A five week flight simulation investigation comparing screen/head stabilized Apache Helmet Mounted Display (HMD) flight symbology to world stabilized flight symbology is presented in this paper. Simulation test results indicate that pilots perform significantly (P<.05) better using world stabilized attitude symbology. They were accurate to an average of 1/2 degree at estimating terrain relief and aerial target locations. Pilots were able to take advantage of world referenced symbology due to the unique features of HMD that allow the pilot to visually use the symbology at extreme azimuth and elevation off-axis angles. Pilots preferred world stabilized symbology while performing contour flight tasks. They reported that the use of climb-dive-marker during contour flight greatly reduced pilot work load under conditions tested. A surprising number of cyclic input errors occured when using both MIL-STD-1295 hover symbology and test symbology indicating that a better approach for depicting hover symbology is probably warranted. The magnitude of cyclic input and spatial estimation errors increased as the off-axis viewing angle became larger.