The computer code named LANS3D, one of the representative Navier-Stokes codes in Japan, is taken as a example and the capability of the current CFD technology is discussed. This code was developed for the numerical simulation of high-Reynolds number compressible flows. The algorithm used in this code and how it has been improved so far explain two important aspects of the computational fluid dynamics (CFD) codes: efficiency and accuracy. Some of the application examples show the capability of the code for engineering problems as well as physical problems. The benchmark test of the newest version of the code on supercomputers indicates that recent supercomputer improvement enables the code to be a strong engineering tool for the design purpose. At the same time, it is concluded that still more compiler improvement may lead to the best use of the supercomputers on the computational fluid dynamics.