Flutter analysis using unsteady aerodynamics in non-Pade form

Aerodynamic coefficient of a flexible aircraft are approximated using a method similar to the one used in Pade approximation but in such a way that completely avoids the penalty of augmented states. The accuracy of the method is tested by a direct comparison between the tabulated and the interpolated aerodynamic coefficients, and by applying the approximation to a flutter example using both open- and closed-loop analysis. Flutter analysis can be performed using the method with no lag terms and no iterations. However, the method cannot yet be applied to design control laws using optimal control theory since the resulting equations are complex.