The flutter of a viscoelastic plate in a supersonic gas flow is studied. A technique and algorithm for numerical solution of nonlinear integro-differential equations with weakly singular kernels are elaborated. The critical flutter speed of viscoelastic plates is determined Keywords: viscoelasticity, supersonic flow, critical speed, nonlinear integro-differential equations with weakly singular kernels, flutter of plate Introduction. In studying elastic and viscoelastic plates in a gas flow, use is often made of various nonlinear equations of motion for a simplified model. Solving the equations for general models involves considerable mathematical and computational difficulties. This makes it difficult to compare the solutions of the plate flutter problem obtained based on different models. The Kirchhoff-Love (elastic waves disregarded) and Berger models produce quite accurate, yet incomplete solutions to some practical problems. In this connection, there is a need to determine the limits of applicability of various theories applied to solve the geometrically nonlinear flutter problem for viscoelastic plates.In the present paper, we analyze the solutions of various nonlinear equations of motion of viscoelastic plates in a supersonic gas flow. We will consider the geometrically nonlinear Donnell-Marguerre, von Karman, and Berger-type equations for the viscoelastic problem formulation. The Bubnov-Galerkin method will be used for spatial discretization. To solve the systems of weakly singular ordinary integro-differential equations (IDEs), we will use a numerical method [1, 2] based on the elimination of weak singularities of integral and integro-differential equations. The solutions obtained from various geometrically nonlinear equations of motion of viscoelastic plates in a gas flow will be compared by determining their critical flutter speeds.1. Governing Equations. According to the general models, the system of equations of motion of viscoelastic plates in a gas flow has the following form [4]: