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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.
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