Accurate aeroelastic requires high performance computational fluid dynamics (CFD) methods bacause the aerodynamic nonlinearity is very dominant in the transonic region. The nonlinear aeroelastic has been peformed using Navier-Stokes, Euler, full potential, and transomic small-disturbance (TSD) equation. Thus, aerodynamic solver using the TSD equation has frequently been used to perform practical aeroelastic analysis for many aircraft models. In this study, the more accurate aeroelastic analysis solver using the TSD theory is developed by considering the viscous effects of the boundary-layer. The viscous effects are considered using Green's lag-entrainment equations for atteched flows. Moreover, an inverse boundary-layer method is used for mild separated flows. Especially, the interactive boundary-layer coupling method is used to minimizethe coupling error between the outer inviscid and inner viscous flows. Though the aerodynamic analyses for several aircraft wings, the viscous-inviscid interaction apporach can omprove the accuracy of the aerodynamic computation using the TSD equation. Finally, the aeroelastic characteristic are investigated using comparisons of the time resposes between the inviscid and viscous flows.