Identification of manual control behaviour to assess rotorcraft handling qualities

Flight safety has been a fundamental aspect of aircraft, and the future demand for wider usage of aerial operations leads to more focus on the flight safety. Particularly rotorcraft require high standards of flight safety due to their inherent features, such as complicated rotary mechanisms, close-to-ground operations, and complex aerodynamic environment. Consequently, rotorcraft pilots need to exert relatively high workload to safely operate these vehicles. An understanding of the interaction between the rotorcraft and the pilot is essential for improving flight safety. This interaction is elaborated by the Handling Qualities (HQ) discipline, which aims to identify and, if possible predict any deficiency in HQ that could potentially jeopardize safe flight. A typical (and potentially catastrophic) example of a HQ deficiency are the Aircraft / Rotorcraft Pilot Couplings (A/RPC), formerly referred to as Pilot Induced Oscillations (PIO). A/RPC is defined as the involuntary and adverse interaction between the pilot and the vehicle under control. Generally for rotorcraft, the ‘vehicle’ part of this interaction is evaluated by objective HQ criteria and online Rotorcraft Pilot Coupling (RPC) detection tools, whereas the ‘pilot’ part is assessed with subjective pilot ratings. Using subjective ratings has several disadvantages, such as being used at very late stages of the design when a prototype vehicle is already built. Addressing a serious HQ deficiency after this late design stage then requires immerse effort to re-design the vehicle systems and repeat the flight tests...