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|A Kawasaki OH-1 on display|
|Manufacturer||Kawasaki Aerospace Company|
|First flight||6 August 1996|
|Status||Active In production|
|Primary user||Japan Ground Self-Defense Force|
|Number built||38 (2014) /150 planned|
The Kawasaki OH-1 (nickname: "Ninja") is a military scout/observation helicopter for the Japan Ground Self-Defense Force, intended to replace the OH-6D Loach. As of March 2014, 38 have entered service, complementing the existing fleet of OH-6D. 
Development and design
In the late 1980s, the Japan Ground Self-Defense Force developed a requirement for a new scout/observation helicopter to replace its Kawasaki license-built OH-6Ds, which became the OH-X programme. Proposals to meet the OH-X requirement were submitted by Kawasaki, Fuji and Mitsubishi, with the Kawasaki design selected as the winner (with Fuji and Mitsubishi serving as subcontractors) on 18 September 1992.
The OH-1 is powered by two Mitsubishi TS1 turboshafts, driving a four-blade composite main rotor with a bearingless rotor hub, while a Fenestron-type rotor-in-tail fan is fitted instead of a more conventional Tail rotor. An electro-optical sensor turret is roof-mounted forward of the rotor head, containing a Forward looking infrared sensor, a laser rangefinder and a colour TV camera. Four hardpoints are fitted under stub wings to allow the carriage of external stores, with a total capacity of 132 kg (291 lb). The outer pylons can carry four Type 91 guided AAMs, while the inner pylons capable of carrying external fuel tanks to extend endurance. No other armament is fitted, but the OH-1 design could be modified to an attack profile with an improved engine and avionics.
The first of four prototypes OH-1s (designated XOH-1) made its maiden flight on 6 August 1996, with the remaining three all flying by March 1997, with deliveries of the four prototypes to the Japanese Defence Agency for service testing from June to August 1997.
Production began in 1998, with the Ground Self-Defense Force initially planning to purchase between 150 and 200 OH-Xs. That would be far fewer than the 297 OH-6Ds KHI had through March 1995, and even this goal could fall prey to the new defense budget realities in Japan. Procurement has been slow with only a few aircraft purchased each year (for example only two 2 OH-1s were purchased in 2004).
The OH-1 is slated to replace the Hughes OH-6D, which remains in service as the primary aircraft in this role.
- XOH-1: Prototypes
- OH-1: Observation helicopter
- Crew: 2, pilot and observer
- Length: 12 m (39 ft 4 in)
- Height: 3.8 m (12 ft 6 in)
- Empty weight: 2,450 kg (5,401 lb)
- Max takeoff weight: 4,000 kg (8,818 lb)
- Powerplant: 2 × Mitsubishi TS1-M-10 ( ja ) turboshaft engines, 660 kW (890 hp) each
- Main rotor diameter: 11.6 m (38 ft 1 in)
- Main rotor area: 105.7 m2 (1,138 sq ft)
- Maximum speed: 278 km/h (173 mph; 150 kn)
- Cruising speed: 220 km/h (137 mph; 119 kn)
- Range: 540 km (336 mi; 292 nmi)
- Service ceiling: 4,880 m (16,010 ft)
- Hardpoints: * 4 × pylons for rockets, gun pods, anti-tank missiles, or Type 91 air-to-air missiles
- Aircraft of comparable role, configuration and era
- Related lists
- "第II部 わが国の防衛政策の基本と防衛力整備" (in Japanese). Japanese Ministry of Defense. Retrieved 2013-06-15.
- "OH-1 Ninja Light Observation Helicopter, Japan". The Global Military Aircraft Market 2011-2021. Army-technology.com. Retrieved 2014-01-31.
- Aoki 1999, pp.37-44.
- Taylor 1999, p.305.
- Sobie, Brendan. "Defence cuts force Japan to slow helicopter output". Flight International, 13–19 January 2004. p.18.
- "World Air Forces 2014". Flightglobal Insight. 2014.
- Aoki, Yoshimoto. "Kawasaki OH-1". World Air Power Journal. Volume 38, Autumn/Fall 1999. London:Aerospace Publishing. ISBN 1-86184-035-7. ISSN 0959-7050. pp. 36–45.
- Taylor, Michael J.H. Brassey's World Aircraft & Systems Directory 1999/2000. London:Brassey's, 1999. ISBN 1-85753-245-7.
|Wikimedia Commons has media related to Kawasaki OH-1.|
- Official JGSDF page
- Kawasaki Aerospace Division OH-1 page
- TS1engine | Mitsubishi Heavy Industries, Ltd.