Assessing Dual-Sensor Enhanced Flight Vision Systems to Enable Equivalent Visual Operations

Abstract

Synthetic vision and enhanced flight vision systems may enable a Next Generation Air Transportation System equivalent visual operations concept: that is, the ability to achieve safety and operational tempos of current-day visual flight rule operations, irrespective of the weather and visibility conditions. The operational feasibility and pilot workload of conducting straight-in instrument approaches in visibility as low as 300 ft by use of onboard dual-sensor imagery on head-up displays, without the need for or reliance on natural vision, were assessed in a motion-base simulation experiment. Twelve crews evaluated two methods of combining enhanced flight vision system imagery on pilot-flying and pilot-monitoring head-up displays, as well as the impact of adding synthetic vision to the sensor imagery, as they made approaches to runways with and without touchdown zone/centerline lights. These new methods were compared to two currently approved operations of head-up displays (with symbology only in 1800 ft visibility, and with forward-looking infrared imagery in 1000 ft visibility). The results indicated that all enhanced flight vision system concepts flown in extremely low visibilities had comparable approach, touchdown, and rollout performance without any workload penalty as compared to the two approved head-up display operational baselines. Adding synthetic vision imagery to an enhanced flight vision system provided situation awareness improvements but no discernible flight-path maintenance improvements or detriments.