From the mid-1980s the Japan Defence Agency (JDA), began to consider a successor to the OH-6D light helicopters currently in service with the Japanese Ground Self-Defence Force. It was decided to procure an indigenous type for the scout/reconnaissance roles. In 1992 Kawasaki was selected as prime contractor with 60 percent of the programme, the balance being allocated equally between Fuji and Mitsubishi. The three companies established the Observation Helicopter Engineering Team to develop the programme, on which detailed work began in 1992.
The resulting OH-1, nicknamed Ninja, is a conventional machine that is relatively small and of typical gunship helicopter configuration. Its structure comprises, by weight, 40 per cent carbonfibre-reinforced plastics, and it features a fenestron type tail rotor.
Each crew member has two LCD colour multi-function displays, and the gunner has a head-up display. The mission avionics include a trainable roof-mounted Kawasaki package (forward of the main rotor) with a Fujitsu thermal imager, NEC colour TV camera and NEC laser rangefinder. Protection is enhanced by the installation of an infra-red jammer on the helicopter's spine to rear of the main gearbox.
The first of six prototypes made its initial flight on 6 August 1996, and the first of a possible 150 to 200 OH-1s was delivered to the JGSDF on 24 January 2000. A total of 14 OH-1s has been ordered for delivery by 2001. The JDA may revise the OH-1 to meet its AH-X light attack helicopter requirement. This would probably feature MTR-390 or T800 engines, allowing the introduction of a heavier weapons load and revised mission avionics. The projected designation of the AH-X production model is AH-2.