Type 91 surface-to-air missile

Development work on an advanced infra-red seeker began in 1979 at the Technical Research and Development Institute (TRDI) after Toshiba and Kawasaki Heavy Industries submitted their projects with the former being selected. In 1982, the Japan Self-Defense Forces began looking for a replacement for the FIM-92 Stinger which was then in service via Foreign Military Sales. Development of the missile was then known as Keiko or SAM-X was deferred until 1987. Toshiba took over the project in 1988 and began engineering development. The development was completed in 1990, and low rate production was started in 1991. The missile was initially designated the Type 91 Kin-SAM and as the SAM-2. It was first deployed in 1994. The adoption of the Type 91 allowed the JSDF to gradually retire the Stingers, with the last stocks officially removed from active JGSDF service in 2009. ==Design==

The missile is similar to the Stinger missile it replaced with two solid rocket motors, an initial booster motor and a sustainer. The Type 91's missile travels at a Mach speed of 1.9. The Type 91 comes with the rocket launcher, an external battery pack, IFF system, missiles and other training equipment. The Type 91 weighs 11.5 kilograms, which is lighter than the Stinger as it has a weight of 15.7 kilograms. Improvements of the Type 91 Kai included missile with image-infra-red seeker, smokeless motor and the capability to have faster shooting and target acquisition and was also improved for the ability to be used at night. ==Variants==

An improved version of the Type 91, called the Type 91 Kai, was delivered to replace the original. A vehicle based variant, the Type 93 Surface-to-air missile launcher, has also been developed. This is also made by Toshiba. The system is mounted on Toyota-made Kōkidōshas. ==Operators==

• Japan Ground Self-Defense Force: The Type 91 is used by the Kawasaki OH-1 as its primary anti-aircraft weapon system ==References==