Flight Guidance Concepts to Mitigate Flight Control System Degradation in Urban Air Mobility Scenarios

Continued safe flight under all foreseeable scenarios will be crucial to assure airworthiness and build trust in future vertical takeoff and landing (VTOL) urban air mobility (UAM) concepts. The successful pilot intervention will be especially important for handling emergency procedures. This article demonstrates the use of human-centric flight guidance concepts to mitigate the effects of noncatastrophic failures in future VTOL UAM aircraft. Specifically, a single failure in the lateral steering function of an automatic flight control system is considered. A new waypoint guidance law is proposed to generate the required roll command to manually steer the aircraft toward a predefined safe landing zone. Two display concepts are proposed to aid the manual execution of the roll steering command: a head-down display (HDD), and a head-mounted display (HMD). The guidance law and the display concepts were integrated into a high-fidelity, wide field-of-view rotorcraft simulation environment. Human-in-the-loop experiments were performed with nonpilot test subjects. The effectiveness of the guidance law and display concepts along with the associated piloting performance and human factor impacts were assessed. The results indicated that all test subjects were able to reach a close vicinity of the final waypoint. The HMD induced a lower workload whereas the HDD resulted in better tracking performance.