M. Alexander

Supporting military rotorcraft life cycle research, the National Research Council of Canada - Flight Research Laboratory integrated a flight loads measurement suite (FLMS) into the NRC-FRL Bell412 Advanced Systems Research Aircraft (ASRA). In the rotor system's rotating frame, main rotor blade, pitch link, and swashplate link loads were captured. In the rotor control system's non-rotating frame, swashplate support, gimbal ring, and boost tube cylinder loads were captured. To examine inter-relationships between control augmentation and rotor system loading, the aircraft was configured with variations of six rate and attitude - based inner-loop control response types spanning Level 1 to 2 ADS-33 handling qualities. Data was analyzed from 3 Hz limited roll-axis frequency sweep tests performed in hover and forward flight. Results highlighted coherence between piloted inputs, fly-by-wire actuation, rotor control component loading, rotor hub dynamics, and vehicular rates. Component load frequency spectra due to rate, attitude, and hold-based responses differed in modal content. Rate- and attitude-based response types associated with the highest and lowest rotor system loading, respectively. Attitude command and -hold (attitude, velocity), response types associated with the greatest change in maximum oscillatory loads between hover and forward flight. Results project critical requirements for ongoing higher-order rotor state measurement research as next generation unconventional, agile, augmented, and pilot-optional vertical lift vehicles are developed.

49th European Rotorcraft Forum 2023, Bückeburg, 2023

Conference Paper

englisch

21,0 x 29,7 cm, 16 Pages

DGLR-Bericht, 2023, 2023-01, 49th European Rotorcraft Forum 2023 - Proceedings; S.1-16; 2023; Deutsche Gesellschaft für Luft- und Raumfahrt - Lilienthal-Oberth e.V., Bonn

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Bestellbar

2023