Development of Rotorcraft Handling Qualities Criteria for Sidestick Force-Displacement Characteristics

The objective of this study is to investigate the influence of the force-displacement characteristics of an active sidestick for the cyclic control on the handling qualities of a cargo/utility rotorcraft with respect to different response types. Three independent, but methodically identical experiments are conducted to study Rate, Attitude and Translational Rate Command response types. Due to the relatively large number of experimental factors, DoE (design of experiments) methods are applied to provide a suitable experimental design. Each test point is evaluated by three different pilots. Nearly 250 MTE evaluations were performed requiring more than 60 hours of piloted simulation. A quadratic regression model is fit to the handling qualities ratings (COOPER-HARPER ratings) for each experiment. An analysis of variance is applied to identify significant model parameters. Optimal force-displacement characteristics are calculated from the regression model for each response type. By analyzing the sensitivity of the handling qualities rating with respect to the stick characteristics, suggestions for appropriate handling qualities criteria are developed. In a final step, insight into the effect of the different response types is gained by comparing the respective optimal force-displacement characteristics.