A Retrospective Survey of Pilot-Structural Coupling Instabilities in Naval Rotorcraft

摘要

Indirect pilot participation with low frequency airframe structural modes is well documented in the fixed wing aircraft community. However, the corollary is not true in rotorcraft. This paper will present and discuss occurrences of pilot-structural coupling in Navy and Marine Corps rotorcraft that have transpired over almost forty years of naval aviation, focusing on flight control system participation in the initiation and sustainment of PAOs. This paper will cover a variety of rotorcraft configurations, from single and tandem rotors to tiltrotors, featuring new and previously reported incidents. The paper will also provide an overview on the topic of pilot-structural coupling, pilot modeling techniques, typical coupling initiation mechanisms and mitigation techniques, as well as analysis and test techniques, with corresponding historical case studies demonstrating the effect of pilot-structural coupling in rotorcraft.