6-DoF Motion Platform simulator (Euler angles)

Hello, I am using the 6-DoF Motion Platform simulator using Euler angles. Why roll, pitch and yaw moments vary with time and not with incidence and Mach number? I have available data for axial, side and normal force coefficients vs incidence and Mach number, and roll, pitch and yaw moment coefficients vs incidence and Mach number. How can I use these data to derive the elapsed time intervals?