A three-dimensional finite element Navier-Stokes solver has been developed for calculating transonic viscous flow on unstructured grids about complex aerodynamic configurations. The solver employs a second-orderaccurate space discretization of the Navier-Stokes equations obtained from a Galerkin weighted-residual approximation. Time discretization is obtained using either an explicit two-step Lax-Wendroff scheme, or an explicit multistep Runge-Kutta scheme. Boundary conditions are implemented using a procedure based on the method of characteristi cs. The overall solution procedure has been initially validated by calculating two- and three-dimensional inviscid and viscous transonic flows.