Synthetic vision is a computer-generated image of the external scene topography that is generated from aircraft attitude,
high-precision navigation information, and data of the terrain, obstacles, cultural features, and other required flight
information. A synthetic vision system (SVS) enhances this basic functionality with real-time integrity to ensure the
validity of the databases, perform obstacle detection and independent navigation accuracy verification, and provide
traffic surveillance. Over the last five years, NASA and its industry partners have developed and deployed SVS
technologies for commercial, business, and general aviation aircraft which have been shown to provide significant
improvements in terrain awareness and reductions in the potential for Controlled-Flight-Into-Terrain incidents /
accidents compared to current generation cockpit technologies.
It has been hypothesized that SVS displays can greatly improve the safety and operational flexibility of flight in
Instrument Meteorological Conditions (IMC) to a level comparable to clear-day Visual Meteorological Conditions
(VMC), regardless of actual weather conditions or time of day. An experiment was conducted to evaluate SVS and
SVS-related technologies as well as the influence of where the information is provided to the pilot (e.g., on a Head-Up or
Head-Down Display) for consideration in defining landing minima based upon aircraft and airport equipage. The
"operational considerations" evaluated under this effort included reduced visibility, decision altitudes, and airport
equipage requirements, such as approach lighting systems, for SVS-equipped aircraft. Subjective results from the
present study suggest that synthetic vision imagery on both head-up and head-down displays may offer benefits in
situation awareness; workload; and approach and landing performance in the visibility levels, approach lighting systems,
and decision altitudes tested.
Synthetic Vision Systems (SVS) displays provide pilots with a continuous view of terrain combined with integrated guidance symbology in an effort to increase situation awareness (SA) and decrease workload during operations in Instrument Meteorological Conditions (IMC). It is hypothesized that SVS displays can replicate the safety and operational flexibility of flight in Visual Meteorological Conditions (VMC), regardless of actual out-the-window (OTW) visibility or time of day. Throughout the course of recent SVS research, significant progress has been made towards evolving SVS displays as well as demonstrating their ability to increase SA compared to conventional avionics in a variety of conditions. While a substantial amount of data has been accumulated demonstrating the capabilities of SVS displays, the ability of SVS to replicate the safety and operational flexibility of VMC flight performance in all visibility conditions is unknown to any specific degree. The previous piloted simulations and flight tests have shown better SA and path precision is achievable with SVS displays without causing an increase in workload, however none of the previous SVS research attempted to fully capture the significance of SVS displays in terms of their contribution to safety or operational benefits. In order to more fully quantify the relationship of flight operations in IMC with SVS displays to conventional operations conducted in VMC, a fundamental comparison to current day general aviation (GA) flight instruments was warranted. Such a comparison could begin to establish the extent to which SVS display concepts are capable of maintaining an “equivalent level of safety” with the round dials they could one day replace, for both current and future operations. Such a comparison was the focus of the SVS-ES experiment conducted under the Aviation Safety and Security Program's (AvSSP) GA Element of the SVS Project at NASA Langley Research Center in Hampton, Virginia. A combination of subjective and objective data measures were used in this preliminary research to quantify the relationship between selected components of safety that are associated with flying an approach. Four information display methods ranging from a “round dials” baseline through a fully integrated SVS package that includes terrain, pathway based guidance, and a strategic navigation display, were investigated in this high fidelity simulation experiment. In addition, a broad spectrum of pilots, representative of the GA population, were employed for testing in an attempt to enable greater application of the results and determine if “equivalent levels of safety” are achievable through the incorporation of SVS technology regardless of a pilot's flight experience.