Plan B for Eliminating Mode Confusion: An Interpreter Display

ABSTRACT

For more than three decades, aviation human factor researchers have analyzed the autoflight system interface (autopilot, autothrottle, flight management system) and articulated its flaws; the design issues are well known. More importantly, autoflight “mode confusion” has contributed to airplane accidents and incidents. A handful of design efforts have produced new interface designs that succeeded in removing or reducing pilot confusion and errors. Despite these efforts, interfaces on the most recent jet transports have changed little, and mode confusion continues to contribute to safety events. The failure to improve interface design is due to economic factors, such as maintaining common type ratings, and reducing certification risk and training costs. This paper reviews previous re-designs as the primary input to a proposed design for an “interpreter” display. The proposed display, implemented as a retrofitted supplementary display, depicts actual autoflight system behavior – What’s it doing now? What will it do next? – in a simple, graphical format. This paper describes the foundational design principles underlying this new display and initial display evaluation work.

Acknowledgments

The evaluation work described in this paper was funded from NASA’s Airspace Operations and Safety Program, System-Wide Safety under Contract NNL16AA15C. Invaluable support in prototyping and evaluation came from Tom Schnell, Matt Cover, and Zeke Gunnink at the University of Iowa Operator Performance Lab; from Lynda Kramer, Renee Lake, Tim Etherington, and Jim Barnes at NASA Langley.

Additional information

Notes on contributors

Randall J. Mumaw

Randall J. Mumaw is a Senior Research Associate employed by San Jose State University; he works as an on-site collaborator at NASA Ames Research Center, Moffett Field, California. He received a PhD in cognitive psychology from the University of Pittsburgh. Dr. Mumaw’s career has focused on operator performance in complex, safety-critical systems.