Flight Test of a Helmet-Mounted, Enhanced and Synthetic Vision System for Rotorcraft Operations.

The success of rotorcraft search and rescue (SAR) operations can be limited by environmental conditions that affect visibility. Poor visibility compromises transit to the search area, the search for the target and departure from the search area. In a joint program, the Canadian Department of National Defense (DND), CAE Electronics Ltd., CMC Electronics Ltd., and the Flight Research Laboratory of the National Research Council of Canada, integrated and flight-tested an enhanced and synthetic vision system (ESVS). The goal of the research program was to examine the potential of the ESVS concept for SAR operations. The ESVS helmet display consisted of a sensor image in the center of the pilot’s field of view, which was combined with a larger computer generated image of the terrain. The combination of sensor and synthetic imagery allowed the accurate detection of obstacles with the sensor while the synthetic image provided a continuous high-quality image, regardless of environmental conditions. The current experiment examined the capabilities and limitations of the ESVS system as an aid for pilots performing runway approaches. Five pilots flew approaches in a Bell 205 Helicopter with the full ESVS imagery (sensor + synthetic terrain imagery), with only the synthetic imagery (no sensor image) and clear-hood (unrestricted visibility). The maneuver began 1.5 miles from the end of the runway, at 500 feet above ground and at 60 knots indicated airspeed. Pilots were required to maintain a constant descent rate down to 20 feet (at 10 knots) above the button of the runway. Despite some of the shortcomings of the ESVS system as tested, the current system demonstrated the potential of ESVS systems. The pilots were able to fly the approaches, using the ESVS system although there were generally larger variations in the approach path. It was concluded that pilots could fly approaches using the synthetically generated terrain image or the full ESVS image. The advantages and limitations of the ESVS system are discussed along with the relative merits of synthetic imagery versus full ESVS imagery for different phases of the approach maneuver.