Although CFD tools are necessary for aerodynamic design, it is still time consuming and this is one of the big problems. In order to shorten the computational time, a fast CFD code “FaSTAR” has been developed. We combined two acceleration techniques. One is a convergence acceleration technique such as the multigrid method. A coarse-grid generation method using octree data of the Cartesian grid is proposed. This method is simple and it can generate high-quality coarse grids. The other is a programing technique such as data structure improvement and performance tuning. We demonstrate the high-speed performance of the code for aerodynamic computation of a standard aircraft model, NASA-CRM. The computational time is less than one hour using 10 million cells and 100 CPU cores. It is found that the multigrid method is beneficial for large-scale problems.