The Ministry of Defense is leaning to develop a follow-on fighter jet on Japan’s own to replace the F-2 as it fears that Japan’s technological expertise in the development of fighter jets may go extinct. The dissipation of fighter jet development knowhow, which is essential to secure Japan’s edge in air superiority, may pose a significant threat to national security.

The MOD has solicited development ideas from U.S. and British firms, envisioning the international development of an F-2 successor model. One of the most promising proposals was made by Lockheed Martin, a U.S. firm, which calls for the joint development of a fighter jet with the F-22 as a base model. The F-22 is reputed to be the world’s strongest fighter jet, which Japan has once considered procuring.

The technological quality of a U.S. military jet is warranted. Thus using this as a base can help Japan minimize development risks and contribute to redressing U.S. trade deficits with Japan, which President Donald Trump considers as problematic. A senior MOD official who attaches importance to the Japan-U.S. relationship says: “This is a realistic idea from the perspective of strengthening the Japan-U.S. alliance.”  

But this will make it difficult for Japanese firms to participate in the development of a fighter jet. Japan has been involved in the joint development of the F-2 fighter jet with the U.S. and accumulated technological expertise through its licensed production of the F-4 and F-15 models. But today, Mitsubishi Heavy Industries stays in the final assembly of F-35A aircraft. If the F-2 follow-on model is to be developed under the U.S. initiative, Japan will be marginalized from the full-fledged development of fighter jets for the next several decades. This will prompt Japanese manufacturers to withdraw from the fighter-jet business.

“We cannot continue to allocate our management resources to the fighter-jet business if the government is not eager to take the initiative,” said a person from the Japanese defense sector. “Engineers who have been involved in fighter jet development are reaching their retirement age. The development of a successor to the F-2 is going to be the last chance for Japan to maintain its technological expertise.”

Liberal Democratic Party lawmakers acting to protect the interests of the defense industry are also supportive of this idea. “It’s a good idea to adopt the F-22’s airframe and some other components, but Japan must make sure it leads the development,” said one of them, adding, “To get the domestic defense industry involved in the development, that message needs to be clearly stipulated in the defense guidelines and mid-term defense program.”

The development using the U.S. military aircraft as a base entails operational risks. The Japanese side could be given limited access to information on the fuselage and systems, which suggests the black-box realm can be expanded. If faults or flaws are found in the U.S. base model, this may create spillover effects, such as flight suspension, and make it difficult to do repairs for performance improvement.

“Japan will have immeasurable benefits if Japan can do all the maintenance work for fighter jets and if Japan can also upgrade its fighter jets on its own,” said Kunio Oda, a former lieutenant general of Japan’s Air Self-Defense Force. “Even though the capability of the aircraft is not satisfactory at the beginning of the development phase, it will be updated,” he added.