United States Air Force head-up display control and performance symbology evaluations

The United States Air Force has conducted an extensive research effort to determine the most effective way to present aircraft control, performance, and navigation information on the head-up display (HUD). The primary objective of the research was to develop a standard HUD symbology set to be used as a primary flight reference for fighter-type aircraft during instrument meteorological conditions. This paper summarizes the research conducted by scientists in the Visual Orientation Laboratory at the Flight Motion Effects Branch of the Human Systems Center's Armstrong Laboratory. Five experiments that examined various control and performance symbology elements are reviewed. Suggested standardization guidelines based on experimental findings are discussed, including the following: the use of counter-pointers for airspeed and altitude indicators, vertical and horizontal asymmetry for climb/dive ladder configurations, a ghost horizon, analog vertical-velocity information, energy management symbology, and quickening for climb/dive markers.