Regime Recognition For MH-47E Structural Usage Monitoring

Concept formulation, detailed design, and initial flight test validation of the flight regime recognition algorithms incorporated in the MH-47E Structural Usage Monitoring System (SUMS) are discussed. These regime recognition algorithms categorize aircraft flight time into regimes for which damage accumulation rates of critical life limited parts are available. The SUMS regime recognition approach is (1) to obtain high quality flight data measurements through the use of innovative wild point editing and forward/backward filtering techniques, (2) to define the maneuver state of the aircraft in terms of a comprehensive set of fundamental maneuvers, and (3) to determine the MH-47E basic fatigue profile flight regime which best describes the maneuver state of the aircraft. Data conditioning, filtering, and failure management techniques are discussed. The use of wind direction and magnitude estimation and inertial/air data blending to obtain high fidelity airspeed estimation at low speeds is described, Maneuver identification algorithms and criteria are presented and validated using flight test data. Methodology for mapping aircraft maneuver state into the MH-47E Basic Fatigue Profile flight regimes in a manner which ensures a conservative, yet realistic, assessment of critical component life expenditure is described. Trades between flight data recorder data storage requirements, regime recognition software complexity and processing time, acquisition of redundant data for failure management, and operational considerations are also discussed.