Interpreting Time-Frequency Analyses of Pilot Control Activity in ADS-33E Mission Task Elements

The present work presents results from a continuing research investigation into the use of multiple methods for analyzing pilot control (inceptor) activity in order to better characterize handling qualities. The investigation involved flight test data that were collected for an OH-58C Kiowa helicopter performing the pirouette mission task element from ADS-33E. Subjective handling qualities ratings were assigned, pilot comments were recorded, and multiple post-test analysis methods were also applied, including the (i) time-varying cutoff frequency, (ii) time-varying power frequency, and (iii) multi-frequency. The interpretation of each of these analysis methods is compared and contrasted. The results demonstrate that analysis methods based on time-frequency representations can provide unique insight into handling qualities evaluations by quantifying the character of the pilot inputs, though these insights must be considered within the context of the mathematical limits of the techniques. These methods may be used to supplement classical (i.e., subjective) techniques in providing added comprehension to assigned handling qualities ratings, particularly for comparative analyses.