The Transfer functions of missiles change during flight. For proper control and desired performance of missiles through different situations during flight, their aerodynamic derivatives and mass inertia parameters need to be corrected at different working points. In this paper the feedback of the tail flap vibrations are used to specify the gains and the aerodynamic parameters of a surface to air missile, for use in the transfer functions. The vibration characteristics of the tail flaps are usually good index of the missile’s speed and consequently its dynamic pressure which, can be used for aerodynamics and gain correction in different working points in the transfer functions. The vibration feedback from the tail flaps were used in a six degree of freedom missile simulation integrated with the tail flaps vibration model and the IMU model. Simulation results and its comparison with recorded results from test flights, shows that the vibration feedback from the tail flaps can quite adequately be used for estimation of missile speed, dynamic pressure, and correction of aerodynamic parameters of the transfer functions.