Developing an Obstacle Display for Helicopter Brownout Situations

Project ALLFlight is DLR's initiative to diminish the problem of piloting helicopters in degraded visual conditions. The problem arises whenever dust or snow is stirred up during landing (brownout/whiteout), effectively blocking the crew's vision of the landing site. A possible solution comprises the use of sensors that are able to look through the dust cloud. As part of the project display symbologies are being developed to enable the pilot to make use of the rather abstract and noisy sensor data. In a first stage sensor data from very different sensors is fused. This step contains a classification of points into ground points and obstacle points. In a second step the result is augmented with ground data bases and depicted in a synthetic head-down display. Regarding the design, several variations in symbology are considered, including variations in color coding, continuous or non-continuous terrain displays and different obstacle representations. In this paper we present the basic techniques used for obstacle and ground separation. We choose a set of possibilities for the pilot display and detail the implementation. Furthermore, we present a pilot study, including human factors assessment with focus on usability and pilot acceptance