Simulation evaluation of equivalent vision technologies for aerospace operations

Abstract

A fixed-based simulation experiment was conducted in NASA Langley Research Center's Integration Flight Deck simulator to investigate enabling technologies for equivalent visual operations (EVO) in the emerging Next Generation Air Transportation System operating environment. EVO implies the capability to achieve or even improve on the safety of current-day Visual Flight Rules (VFR) operations, maintain the operational tempos of VFR, and perhaps even retain VFR procedures -all independent of the actual weather and visibility conditions. Twenty-four air transport-rated pilots evaluated the use of Synthetic/Enhanced Vision Systems (S/EVS) and eXternal Vision Systems (XVS) technologies as enabling technologies for future all-weather operations. The experimental objectives were to determine the feasibility of XVS/SVS/EVS to provide for all weather (visibility) landing capability without the need (or ability) for a visual approach segment and to determine the interaction of XVS/EVS and peripheral vision cues for terminal area and surface operations. Another key element of the testing investigated the pilot's awareness and reaction to non-normal events (i.e., failure conditions) that were unexpectedly introduced into the experiment. These non-normal runs served as critical determinants in the underlying safety of all-weather operations. Experimental data from this test are cast into performance-based approach and landing standards which might establish a basis for future all-weather landing operations. Glideslope tracking performance appears to have improved with the elimination of the approach visual segment. This improvement can most likely be attributed to the fact that the pilots didn't have to simultaneously perform glideslope corrections and find required visual landing references in order to continue a landing. Lateral tracking performance was excellent regardless of the display concept being evaluated or whether or not there were peripheral cues in the side window. Although workload ratings were significantly less when peripheral cues were present compared to when there were none, these differences appear to be operationally inconsequential. Larger display concepts tested in this experiment showed significant situation awareness (SA) improvements and workload reductions compared to smaller display concepts. With a fixed display size, a color display was more influential in SA and workload ratings than a collimated display.

Visual Features Involving Motion Seen from Airport Control Towers

“…For this purpose the currently used visual information needs to be provided by alternative means. Such "Equivalent Visual Operations" described FAA/NASA planning documents may be achieved with synthetic visual system, i.e., (Kramer, Williams, Wilz & Arthur, 2008) visual replacement with visualized electronic position data. But these replacements will not be fully successful, and may even be tragically misleading, if the useful visual affordances provided by the real scene are not appropriately provided.…”

Enhanced vision for all-weather operations under NextGen

“…In the full-factorial experiment design, this variation also tested the effect of peripheral cues on HUD landing, albeit without any forward out-the-window visual cues other than the EV HUD. 20 The presence or absence of peripheral cues did not create any operationally significant differences in pilot workload or situation awareness in the flare and landing task. (Quantitative landing performance issues are discussed in Section 4.2).…”

“…• 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.…”

“…Reference source not found. 17 technique was used to calculate the probability of success, P(α), of meeting the AWO exceedance criteria (⅓ dot localizer, 1 dot glideslope) with required levels of confidence for the HUD display concepts flown during the XVS/AWxL 20,21 and CaD-CE 18,19 experiments.…”

“…The PF used an EFVS HUD showing approximately 4800 ft visibility with the forward view otherwise obscured to manually land the simulated B-757 aircraft. 20,21 An autothrottle was set to "speed-hold" at the approach speed of 132 KIAS, using V ref +5 for the simulated landing weight. The pilots were instructed to disengage the autothrottle for landing.…”