The VaRTM process is a low cost composite fabrication technique, differing from prepreg laminated composites, the resin is infused into dry fabric formed on a mold near product shape under vacuum pressure and cured in an oven. This process has already been utilized in the manufacture of commercial products such as windmills. This study examined ways to improve existing VaRTM techniques so that they can be applied to the fabrication of aircraft primary structures, and to improve VaRTM materials, processes, and cost. It was verified that the mechanical properties of VaRTM materials are almost equivalent to those of prepreg materials, and that the prospects of applying them to the empennage of the Mitsubishi Jet are feasible. Development work is proceeding with the aim to realize further cost reductions and to obtain conformance to regulatory on the application of this process to the production of civil commercial aircraft in the future.