Evaluation of a Haptic Feedback System for Flight Envelope Protection

Modern fly-by-wire aircraft use flight envelope protection systems, whose actions are not always clear to pilots. To promote situation awareness, proximity to the limits of the flight envelope can be communicated using haptic feedback, by providing forces through the control device. Such a system was developed and this paper reports on the evaluation experiment. Professional pilots were invited to fly an Airbus A320 model in the Delft University of Technology Simona research simulator. A windshear and an icing scenario were flown using a full and degraded control law, with and without the haptic feedback system. The objective results show that the haptic feedback system does not lead to significant improvements in either performance or safety metrics, but also does not interfere with nominal pilot tasks. In the debriefing questionnaire, however, pilots expressed a clear preference for the haptic system. Recommendations for future research include the addition of visual support to complement the haptic cues, and the redesign of the scenarios to allow pilots more freedom in control.