The civil light helicopter domain has not fully benefited yet from the advantages system identification methods can offer. The aim of this paper is to show that system identification methods are mature enough to be successfully implemented in the civil helicopter domain. To achieve this goal, a Robinson R44 Raven II is identified in this work. The identification focuses on the hover trim condition. A lean frequency domain identification method is adopted. Furthermore, a new procedure is proposed to limit the sensitivity of the state-space minimization algorithm to initial parametric values and bounds. The resulting state-space model presents good predictive capabilities and is able to capture high frequency rotor-body dynamics. The model is also validated with the help of a helicopter pilot by performing closed-loop control task maneuvers in the MPI CyberMotion Simulator. The g gravitational acceleration, [m/s 2 ] s Laplace transform variable φ, θ, ψ fuselage angular attitude (roll, pitch, yaw) earth-fixed coordinates, [rad] β 0 , β 1c , β 1s rotor coning, longitudinal and lateral flapping angles, [rad] τ f rotor flap time constant, [s] ν rotor inflow velocity, [m/s] ν0 trim inflow ratio γ Lock number ξ, ω damping and natural frequency of a second order system η Ct integrated perturbation thrust coefficient σ rotor solidity ρ atmospheric density, [Kg/m 3 ] δ lat , δ lon , δ ped , δ col helicopter control inputs (lateral cyclic, longitudinal cyclic, pedals rudder, collective lever), [deg] Ω rotor rotation speed, [rad/s] ω frequency, [rad/s]
