Investigation of Certification Considerations for Distributed Electric Propulsion (DEP) Aircraft

FAA Technical Libraryhttps://doi.org/10.21949/15244922022PDFTech ReportMcKillip, R. Jr.Wachspress, DContinuum Dynamics, IncUnited States. Department of Transportation. Federal Aviation Administration. Aviation Research DivisionUnited States. Department of Transportation. Federal Aviation Administration. William J. Hughes Technical CenterUnited StatesAircraftControl system applicationsPropulsionRemote sensingVTOL aircraftAdaptive controlRemaining control powerdistributed electric propulsioneVTOL aircraftloss of control sensingDOT/FAA/TC-22/15692M15-20-T-00040Year 1 Final Report 9/9/2020-5/1/2022Efforts from the first year of a multi-year investigation examining the use of estimation of both remaining vehicle control power margins and external environmental disturbances for distributed electric propulsion (DEP) vehicles as a contributor for vehicle certification are described. This study combines simulation of DEP aircraft with experimental testing of representative models in the assessment of algorithms for determining remaining control power margins in real-time operation of these vehicles, to provide a metric for the capability of that vehicle to accommodate operational disturbances and avoid loss of control (LOC) events. The Comprehensive Hierarchical Aeromechanics Rotorcraft Model (CHARM) analysis for aerodynamic interaction effects on these configurations is being used to simulate and characterize vehicle response to disturbances and to applied control inputs throughout its flight envelope. The goal of the effort is to determine the viability of the methods for calculation of remaining control power margins, and to assess the utility of the methods in safety monitoring of DEP flight operations for both manned and unmanned vehicles. This first year of research has shown that application of algorithms for estimating remaining available vehicle control power, and local gust disturbance magnitudes, appear to provide a usable safety assessment for avoiding loss of control (LOC) events for eVTOL/DEP aircraft. A follow-on research project will expand the algorithm application for control equivalent gust estimation and extraction of local disturbance flows.137