Flight Assessment of Pathway in Sky Symbology Using Display Night Vision Goggles

This paper describes an assessment of advanced Pathway-in-Sky symbology displayed on Display Night Vision Goggles. The work was performed in October-November 2004 and was the most recent in a series of trials aimed at establishing the operational utility of such symbology in increasing the operational effectiveness of pilots in performing Nap of Earth and Low Level Transit tasks in extremely poor visual environments. The same Trials Equipment and Display Night Vision Goggle developed under a previous trial were used and two different types of pathway symbology were investigated. The robustness of the three dimensional Pathway-in- Sky illusion was tested by tasking the pilots to follow the route as accurately as possible. A pathway performance metric was developed to assess the performance in such a way that did not penalise the pilots for adopting normal pilotage techniques, for example deliberately flying off the centre of the track. Analysis of the results showed that Tunnel pathway symbology performed better in minimising path following error than open Trough shaped gates. The technique was also applied to a complex multi-axis control task with similar results.