Ecological Approach to Support Pilot Terrain Awareness After Total Engine Failure

Abstract

Terrain awareness enhancing avionics, such as Synthetic Vision Systems and the Enhanced Ground Proximity Warning System, have been developed to reduce the number of controlled flight into terrain accidents. The protection these systems offer, however, is far from optimal. Synthetic Vision Systems only provide pilots with perceptual data, and leave all cognition and interpretation of data to the pilot. With Enhanced Ground Proximity Warning Systems the opposite is true. Here, pilots are only confronted with compelling advisories and commands without the underlying data and rationale. This paper presents a display system, the Emergency Landing Guidance System, that visualizes the functional of surrounding terrain, adopting an ecological interface design approach. The potential benefits of this approach are demonstrated with the case of locating and approaching a suitable landing area after sudden complete engine failure. To evaluate the effect of the new display on pilot terrain awareness, an experiment was conducted in a fixed-base flight simulator. Results show that the new display supports pilot terrain awareness much better than present terrain avoidance systems, i.e., pilots better understand the meaning of the terrain in relation to their goals and constraints. However, pilots also operated more closely to the limits of performance, thereby negatively affecting the metrics for safety.