Vertical Lift Aircraft Rotor and Blade Mechanical and Dynamic Fault Detection in the field through the use of Revolution to Revolution Blade Track Data Analysis

Rotor and blade fault detection using optical blade tracking revolution-to-revolution data is described in this paper. The process allows analysis of the dynamic health of an individual blade and its attachments, indicates rotor eccentricities, and faulty collective and cyclic functions. The process is detailed in US Patent 8,041,520 B2 issued October 18, 2011. Smoothing algorithms are applied to the data to remove sensor and rotor induced motion. The data are then reordered by amplitude ranging from most positive to most negative. Forced motion values are then at the extremes of the data set placing the normal range of motion about the median value of each data set. Identification of forced motion; e.g., pilot control input, meteorological disturbances, etc., and normal unforced motion is critical for fault analysis. Motion analysis aids blade and rotor fault discovery and repair. The process can be used for recovery of faulted blades in the field.