Visual Workload of the Copilot/Navigator during Terrain Flight

The emphasis on aviator workload has been of primary concern to the U.S. Army aviation community since the incorporation of low altitude terrain flight techniques into the helicopter tactics repertory. Since navigation is a particularly acute problem at low altitudes, this project examined the visual workload of the navigator/copilot during terrain flight (nap-of-the-earth, contour, and low level) in a UH-1H helicopter. Visual performance was measured via a modified NAC Eye Mark Recorder used in conjunction with a LOCAM high speed camera. This technique provided the means to record objectively and analyze the navigator's visual performance.

A visual free time task was utilized to determine the amount of visual time the navigator had available, during flight over the prescribed course, for a nonflight-related task. The data indicate that the navigator's normal workload was demanding; the visual free time task was utilized only 3% of the total time. The data also indicate that the duty of navigating required 92.2% of the copilot's total visual time, while the engine and flight instruments were utilized only 4% of the time. These data are discussed in relation to the copilot's specified duties.