Experimental Hingeless Rotor Characteristics at Full Scale First Flap Mode Frequencies (including Rotor Frequency Response to Shaft Oscillations), Phase 3

The completion of the High Advance Ratio Research Program is reported. The primary objectives of the program were to experimentally determine the rotor frequency response to shaft pitching and rolling oscillations and to acquire steady response and frequency response data at high advance ratios for hingeless rotors with typical, full-scale, first flap mode natural frequencies. Secondary objectives of the program included the further evaluation of both the hub moment feedback control system and the simplified rigid blade flapping theory with respect to shaft oscillations. The bulk of the text is devoted to the presentation and examination of representative experimental results. All the analyzed test data are documented in tabular and/or graphical formats.