Human factors evaluation of a dynamic channel depiction of navigation procedures in SVS displays

Abstract

Synthetic vision systems (SVS) are studied for some time to improve pilot's situational awareness and lower their workload. Early systems just displayed a virtual outside view of terrain, obstacles or airport elements as it could also be perceived through the cockpit windows in absence of haze, fog or any other factors impairing visibility. Required digital terrain, obstacle and airport databases have been developed and standardized by Jeppesen as part of the NASA Aviation Safety Program. Newer SVS displays also introduced different kinds of flight guidance symbology to help pilots to improve the overall flight precision. The method studied in this paper is to display navigation procedures in the form of guidance channels. First releases of the described system used static channels, generated once at the startup at the system or even offline. While this approach is very resource friendly for the avionics hardware, it does not consider the users, which want the system to respond to the current flight conditions dynamically. Therefore, a new application has been developed which generates both the general channel trajectory as well as the channel depiction in a fully dynamic way while the pilot flies a navigation procedure.At the beginning of the development of the new system, a human factors workshop with GA, BA and CA pilots and charting experts has been conducted to identify the pilot's expectations and requirements for a channel guidance. The workshop covered a general information and task analysis to reveal what information the pilots need while flying a procedure. Two other sessions dealt with the generation of the channel trajectory and the depiction of the channel trajectory. Based on the results of the workshop, the channel trajectories are generated dynamically using the flight mechanical properties of the aircraft in order to make the trajectory easily flyable even in turns and within the performance parameters of the aircraft. Trajectories can be generated for ARINC424 coded STARs and approaches. Additional trajectories and guidance cues for intercepting or reentering a procedure are generated, as well as ATC commands like radar vectors and missed approach procedures. The generated trajectories are verified to ensure they do not conflict with special use airspaces, obstacles and terrain. Besides new algorithms to generate the tunnel trajectory dynamically, different concepts for a dynamic trajectory depiction have been implemented and tested as well. Finally, the components of the new SVS display have been compared in a simulator evaluation. An approach to Colorado Springs has been used to check three different tunnel depictions either with or without 2D guidance cues on STARs, Approaches and Radar Vectors into this airport. A scenario at Frankfurt/Germany has been used to validate different algorithms to generate trajectories in the turns of the S-shaped RNAV-transition into Frankfurt. The situational awareness of the pilots has also been supported by a simple navigation display which showed the...