Synthetic Vision Enhances Situation Awareness and RNP Capabilities for Terrain-Challenged Approaches

Abstract

The Synthetic Vision Systems (SVS) Project of Aviation Safety Program is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft through the display of computer generated imagery derived from an onboard database of terrain, obstacle, and airport information. To achieve these objectives, NASA 757 flight test research was conducted at the Eagle-Vail, Colorado airport to evaluate three SVS display types (Head-Up Display, Head-Down Size A, Head-Down Size X) and two terrain texture methods (photo-realistic, generic) in comparison to the simulated Baseline Boeing-757 Electronic Attitude Direction Indicator and Navigation / Terrain Awareness and Warning System displays. These independent variables were evaluated for situation awareness, path error, and workload while making approaches to Runway 25 and 07 and during simulated engine-out Cottonwood 2 and KREMM departures. The results of the experiment showed significantly improved situation awareness, performance, and workload for SVS concepts compared to the Baseline displays and confirmed the retrofit capability of the Head-Up Display and Size A SVS concepts. The research also demonstrated that the pathway and pursuit guidance used within the SVS concepts achieved required navigation performance (RNP) criteria.

Pathway concepts experiment for head-down synthetic vision displays

“…What is the best way to display the synthetic vision scene and what are the database and sensor requirements to ensure the integrity of a synthetic vision system? To date, a significant amount of human factors research has been conducted at the NASA Langley Research Center to investigate these issues (e.g., Arthur et al, 2003;Kramer et al, 2003;Prinzel et al, 2001;2002;. Many of these issues have been resolved, but several significant ones still remain.…”

<title>Flight test comparison between enhanced vision (FLIR) and synthetic vision systems</title>

“…In operational terms, the differences are small (0.04 nm FTE vs. 0.1 nm FTE) when compared to current aircraft equipage that shows FTE on the order of 0.25 nm. 16 The primary differences between these concepts, with respect to flight path performance, was the HUD or HDD background (none, EVS, or SVS), the presence/absence of the tunnel, and the presence/absence of track change information (tadpole or dual cue guidance symbol).…”

<title>Initial development of a metric to describe the level of safety associated with piloting an aircraft with synthetic vision systems (SVS) displays</title>

“…The results of the SVS-GA Terrain Portrayal for Head Down Displays (TP-HDD) simulation and flight test and the Symbology Development for Head Down Display (SD-HDD) simulation experiments Takallu et al, 2004;Wong et al, 2004), as well as other SVS research conducted by NASA (e.g. Kramer et al, 2003), academia, and industry, all indicate that a pilot's situation awareness (SA) can be substantially improved when flying in IMC by providing a SVS terrain background on a primary flight display (PFD) or even Head-Up Displays (HUDs) (Prinzel & Comstock et al, 2004). Furthermore, overlaying the SVS terrain with a highway-in-the-sky (HITS), or other pathway based guidance symbology, results in very precise aircraft maneuvering without causing a significant increase in the workload associated with flying an approach, executing a missed-approach, or flying enroute maneuvers Kramer et al, 2003;Takallu et al, 2004;Wong et al, 2004;.…”