Simulation evaluation of synthetic vision as an enabling technology for equivalent visual operations

Abstract

Enhanced Vision (EV) and synthetic vision (SV) systems may serve as enabling technologies to meet the challenges of the Next Generation Air Transportation System (NextGen) Equivalent Visual Operations (EVO) concept -that is, the ability to achieve or even improve on the safety of Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and even, perhaps, retain VFR procedures independent of actual weather and visibility conditions. One significant challenge lies in the definition of required equipage on the aircraft and on the airport to enable the EVO concept objective. A piloted simulation experiment was conducted to evaluate the effects of the presence or absence of Synthetic Vision, the location of this information during an instrument approach (i.e., on a Head-Up or Head-Down Primary Flight Display), and the type of airport lighting information on landing minima. The quantitative data from this experiment were analyzed to begin the definition of performance-based criteria for all-weather approach and landing operations. Objective results from the present study showed that better approach performance was attainable with the head-up display (HUD) compared to the head-down display (HDD). A slight performance improvement in HDD performance was shown when SV was added, as the pilots descended below 200 ft to a 100 ft decision altitude, but this performance was not tested for statistical significance (nor was it expected to be statistically significant). The touchdown data showed that regardless of the display concept flown (SV HUD, Baseline HUD, SV HDD, Baseline HDD) a majority of the runs were within the performance-based defined approach and landing criteria in all the visibility levels, approach lighting systems, and decision altitudes tested. For this visual flight maneuver, RVR appeared to be the most significant influence in touchdown performance. The approach lighting system clearly impacted the pilot's ability to descend to 100 ft height above touchdown based on existing Federal Aviation Regulation (FAR) 91.175 using a 200 ft decision height, but did not appear to influence touchdown performance or approach path maintenance.

Testing the Efficacy of Synthetic Vision during Non-Normal Operations as an Enabling Technology for Equivalent Visual Operations

“…Of particular relevance to this paper and the subsequent discussion of the EPs reaction to non-normal events is that all nominal approaches (92 total runs) flown in these same flight conditions (MALSR ALS, 100 ft DA, 2400 ft RVR) resulted in a landing (i.e., no missed approaches) (see Kramer et al, 2008).…”

Enhanced vision for all-weather operations under NextGen

“…• Crew and Display Concepts Evaluation (CaD-CE) for Synthetic / Enhanced Vision 18,19 • Synthetic Vision Systems -Operational Considerations (SVS-OC) 12 • eXternal Visibility System (XVS) /All Weather Landing (AWxL) (XVS/AWxL) 20,21 The objectives of these three experiments were not specifically targeted toward the development of performancebased all-weather landing requirements; but they do provide piece-wise information toward this goal. Just as importantly, their assumptions and limitations identify areas of future research, as discussed in the following.…”

“…The data suggests that the 3 second rule, despite its dated heritage, is valid and should be met to provide landing line-up, control, and touchdown performance. 12 …”

“…NASA and others have developed and shown SV technologies to provide significant improvements in terrain awareness and reductions for the potential of Controlled-Flight-Into-Terrain incidents/accidents, [3][4][5] improvements in flight technical error to meet Required Navigation Performance criteria, [6][7] and improvements in situation awareness (SA) without concomitant increases in workload compared to current generation cockpit technologies [8][9][10][11][12] As such, SV is emerging as "standard equipage" for Part 23 and Part 25 business and general aviation aircraft flight decks even though, to date, no "operational credit" is obtained by SV equipage.…”

Simulation evaluation of equivalent vision technologies for aerospace operations

“…The Continuous Method was applied to data from a prior experiment 13 for comparison. In this experiment, pilots evaluated the use of SV on a HUD during an instrument approach but they were required to transition to a natural vision segment, just as they would have to do today under existing operating regulations.…”