ABSTRACT
This study investigated the utility of alternative helmet-mounted display (HMD) symbologies for flight control and target acquisition. All symbologies presented information on aircraft altitude, airspeed and course/way points, but differed in their inclusion of either attitude or ground collision information. RAF aircrew flew a high speed, low level, simulation mission over mountainous terrain in the DRA fused imagery simulation testbed. Aircrew were required to fly within specified height, speed and course parameters, and to search for and acquire a number of off-boresight airborne and ground-based targets, using a helmet-mounted target designator. A battery of measures was taken. Four types of HMD symbology were used: the pitch ladder, empty HMD, advisory textual cue, and schematic terrain; these last two displays provided up-ahead terrain clearance information. Results favoured the schematic terrain format most and the pitch ladder format least. The implication of these results for HMD design is discussed.
