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.
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