the maximum deflection has been provided which = 0.3 m (Value Assumed ) For lynx 300 Helicpter
Mass of the helicopter = 5126 Kg
sink speed = 0.5m
k= F/x = 5126/0.3 = 167620.2 N/m
Need to find out damping ratio and Damping Coeficient at which the helicopter will have a deflection of 0.3 m