Use of an Enhanced Flight Vision System (EFVS) for Taxiing in Low-Visibility Environments

摘要

Two studies (Boeing 777 and 737 simulators) examined flight crews' use of an Enhanced Flight Vision System (EFVS) for taxiing in low-visibility conditions in lieu of infrastructure for Low-Visibility Operations/Surface Movement Guidance and Control Systems (LVO/SMGCS). Twenty-five flight crews completed 21 short taxi scenarios under combinations of the following variables and levels: Runway visual range (RVR; 300, 500, 1000 ft); Enhanced-Flight-Vision System in head-up display (on/off); airport infrastructure - 3 levels. Two scenarios dealt with detecting obstacles near the taxi path. In both studies, the use of EFVS resulted in fewer route deviations, the majority of which occurred at 300 feet RVR with edge lights and either a standard painted centerline (Level 1) or a painted centerline with LVO/SMGCS 'enhancements' but without centerline lights (Level 2). Deviation from taxiway centerline was variable, but was consistent between display conditions (EFVSo EFVS) (mean <4 ft). Larger turn angles and lower visibilities were associated with slower rates of travel. Flight crews in both studies detected the right-side obstacle the majority of the time, and about twice as often as they detected the left-side obstacle. Regardless of EFVS, flight crews in both studies made more route deviations on larger turns and right turns. Pilot feedback suggested the issue was loss of visual references to the turn, particularly without centerline lights. Recommendations are provided regarding the benefits and limitations of EFVS for low-visibility taxi operations, procedures for low-visibility taxi operations in general, and suggestions for future research.