Description: Development of new air vehicles have led to a proliferation of Vertical Takeoff and Landing (VTOL) concepts including electric vehicles. These vehicles will almost exclusively feature fly-by-wire flight control systems with advanced response-types. The processes and requirements needed to certify these disparate vehicles for operation within the National Airspace System are still emerging. Systems Technology, Inc. (STI) has defined and assessed means of compliance (MOC) to aid in the requirements and certification process, through analysis and piloted simulation in the form of Handling Qualities Task Elements (HQTEs). These vehicles will operate not just with human passengers onboard, but also in close proximity to densely populated areas that generates risks to both ground-based humans and property. To minimize these risks, there is a significant need to identify system faults before they can result in failures that ultimately lead to a major accident. Building upon work done via an ongoing Phase II for NASA on fault estimation and system redundancy (i.e., the STI Approach to Fault Estimation via Redundancy – SAFER), and the ongoing work for the FAA, Systems Technology, Inc. (STI) will provide at the end of this Phase II extension a set of HQTEs that address transitions from forward to vertical flight, envelope protection, increased automation, and initial considerations for faults and failures for each HQTE. This effort will begin by conducting system surveys of a UAM model, characterizing the model in the time and frequency domains, including baseline and degraded handling qualities conditions. Forward flight to hover transition methodologies, envelope protection schemes and automation will be developed and integrated into the model for testing under the baseline and degraded conditions. The potential faults within these systems and overall system reliability will be examined under the SAFER framework, extending the Phase II work from UAS to UAM.

Benefits: SAFER-UAS/UAM applies to three of the NASA Aeronautics Strategic Implementation Plan’s six strategic thrusts: 1: “Safe, Efficient Growth in Global Operations,” 5: “Real-time, System-Wide Safety Assurance,” and 6: “Assured Autonomy for Aviation Transformation.” It also addresses NASA’s involvement in air traffic management for low-altitude drones. SAFER-UAS/UAM will help NASA achieve its goals of ensuring safe and timely integration of UAS/UAM into the NAS and support the objectives of the Revolutionary Vertical Lift Technology (RVLT) Program.

SAFER-UAS/UAM is expected to be of interest in the growing UAS and emerging eVTOL marketplace, including government and commercial entities at all stages of the process. A tool such as SAFER-UAS/UAM – that allows confident reliability assessment and also provides support for design of more reliable algorithmically redundant architectures – will be a valuable asset to these rapidly growing markets.