Terrain Display Alternatives

Book excerpt: Current technology makes it possible to display navigation and terrain information on electronic screens in the cockpit. The conventions used for position and terrain information must be clearly presented so pilots can maintain their positional awareness and avoid collision with terrain. There are very few recommendations or guidelines available for the design and evaluation of electronic displays. The Volpe National Transportation Systems Center (Volpe Center), in support of the Federal Aviation Administration's (FAA's) Office of the Chief Scientific and Technical Advisor for Human Factors, AAR-100, conducted a series of experiments to explore human factors issues in depicting terrain on electronic displays. Experiments examined instrument-rated General Aviation (GA) pilots' ability to interpret terrain shown on electronic plan view displays in a flight simulator. The four experiments examined the following electronic display alternatives: (1) the utility of presenting nonthreatening terrain during approaches; (2) effectiveness of showing only terrain features for terrain avoidance; (3) preferences for information density; and (4) the utility of terrain displays paired with visual terrain alerts. Results suggest display designs should incorporate alerts that identify danger and reorient pilots. Electronic displays with terrain that incorporate these recommendations should diminish the number of accidents resulting from a loss of positional awareness, such as controlled-flight-into-terrain (CFIT) accidents.