Commercial Flight Crew Decision Making During Low-Visibility Approach Operations Using Fused Synthetic and Enhanced Vision Systems

Abstract

The use of an enhanced vision (EV) system in civil aircraft is projected to increase rapidly as the Federal Aviation Administration recently changed the aircraft operating rules under Part 91, revising the flight visibility requirements for conducting operations to civil airports. Operators conducting straight-in instrument approach procedures may now operate below the published approach minimums when using an approval EV system that shows the required visual references on the pilot's Head-Up Display (HUD). An experiment was conducted to evaluate the complementary use of synthetic vision (SV) and EV technologies, focusing on new techniques for integration and/or fusion of synthetic and enhanced vision technologies under the newly adopted FAA rules. The current paper describes a fixed-based simulation experiment that evaluated several display concepts located on the pilot-flying HUD and pilot-not-flying auxiliary display. Results specific to flight crew response, during non-normal events and below minimum visibility, using the fused synthetic/enhanced vision system are discussed here. The results demonstrated that the integrated SV/EV display did not adversely impact detection of lateral navigational solution errors on runway incursions. Additionally, flight crews were able to effectively use existing EV system procedures in their decision-making but found the visual transition from an excellent EV image to natural vision by 100 ft height above touchdown to be awkward. Finally, the addition of scene-linked symbology significantly enhanced flight crew go-around decision-making and reduced the number of illegal landings during approaches in which the required visual references to continue the landing were unavailable.