Supporting Pilots in Close Encounters with Terrain

Despite the fact that modern cockpits present an abundance of information to pilots, Controlled Flight Into Terrain (CFIT) accidents continue to occur. The introduction of terrain awareness and warning systems, like the Enhanced Ground Proximity Warning System (EGPWS), has led to a considerable reduction of terrain incursions. EGPWS predicts the aircraft motion relative to terrain and, based on a rule-base of advanced reasoning logic, informs pilots on how to react appropriately. Common to all terrain warning systems, is that all cognition is ‘hidden’ in the EGPWS logic, and pilots are required to respond rapidly to the system’s commands. We hypothesize that pilot decision making is accelerated and situation awareness is improved when the internal functioning of terrain awareness and warning systems is clarified, visualized on the interface. To test this hypothesis we developed two extensions to the EGPWS. In the first, the EGPWS flight path prediction was presented, to clarify the look-ahead function. In the second, also the potential escape trajectories were presented. A simulator experiment was conducted where twelve general aviation pilots were brought in close encounter with terrain, with the three EGPWS variations. Results show that when the EGPWS internal reasoning is visualized to pilots, situation awareness significantly improved