Publisher Summary This chapter describes the three-dimensional Navier-Stokes simulations about the wing of the Boeing 747 by using a parallel vector computor called numerical wind tunnel (NWT). The main objective is to simulate the wing-tip vortex. The governing equations are three-dimensional Reynolds-averaged thin-layer Navier-Stokes equations, which are discretized by finite volume method with a total variation diminishing (TVD) upwind scheme. The domain around the wing is decomposed into 24 sub-domains, but the grid system is basically in C-O topology. The grid around the wing with wake is algebraically generated using transfinite interpolation. The method of the parallelization is to share the load of computation for each sub-domain to each processor element (PE). Computation using a grid with 11-million grid-points shows an existence of a strong tip vortex induced by the wing. The numerical solutions obtained here have been compared with the wind tunnel test data for the computational fluid dynamics (CFD) code validation.