In 1968,
Japan selected a modified version of the
F-4E as the next main future fighter of the Japan Air Self-Defense Force with the possibility to employ the AIM-4D being an important factor of the decision. The development of the XAAM-2 was started in 1970 as an
air-to-air missile for the newly acquired
F-4EJ. It was developed by the Technical Research and Development Institute and Mitsubishi Heavy Industries, aiming to exceed the performance of the original
AIM-4D. The guidance system used infrared homing like the AIM-4D, but improved to a limited all-aspect infrared homing with the ability to attack from the front and side of the enemy aircraft with the reliability of electronic devices also improved. The missile employed a higher performance rocket motor expanding its range. In addition, the warhead power was increased compared to the AIM-4D, and it was equipped with a proximity fuze, solving major issues of the AIM-4D, such as the small warhead and the lack of a proximity fuze. Therefore, although the AAM-2 is very similar in appearance to the model AIM-4, it employed a different motor, warhead and guidance system. While being successfully tested, the AAM-2 never entered production due to higher cost compared to the American-made AIM-4D, with a high surplus stock after the
Vietnam War. Japan rather imported the AIM-4D to equip its F-4EJ aircraft. The development of XAAM-2 was discontinued in 1975. ==See also==