Robust 3-D Algorithm for Flare Planning and Guidance for Impaired Aircraft

Development of a robust nonlinear guidance law for planning and executing the flare-touchdown maneuver for impaired aircraft under adverse wind conditions is proposed. The approach employs estimated operational envelope of the damaged aircraft and ambient winds to plan flap deployment schedule and the flare-touchdown maneuver. The algorithm will also provide guidance for precise execution of the terminal de-crab maneuver in the presence of crosswinds. The guidance law will be formulated in terms of aircraft attitude components to enable direct coupling with the autopilot or for providing pilot guidance through the flight director. Phase I research will demonstrate the feasibility of the proposed guidance law in an aircraft simulation. Robustness to unmodeled dynamics and uncertainties will be demonstrated. Phase II research will develop standalone guidance law implementation in a real-time operating system for NASA-specified aircraft model. This implementation will then be coupled with a high-fidelity manned simulation to assess its performance under realistic operational scenarios. Algorithms and software developed under the proposed research will be provided to NASA at the end of Phase II research. Phase III work will focus on flight test evaluation of the robust flare guidance law.