The Japan Defence Agency (JDA) is seeking initial funding in its next budget to begin a formal study of future attack helicopter requirements. Interested local and foreign suppliers are already formulating a range of options with which to respond.

Full-scale funding for the AH-X programme is expected in the next five-year mid-term defence plan, starting in fiscal year 2000. The first replacement for the Japan Ground Self-Defence Force's (JGSDF) 85 Fuji-licence produced Bell AH-1S Cobra helicopters may be available in 2003.

The JGSDF is believed to be focusing its attention on a tandem seat, twin engine design, with an all-weather capability. In particular, it is looking for a longer range successor to the single turboshaft-powered AH-1S, offering improved performance over Japan's mountainous island terrain.

Given the JDA's increasingly tight budget appropriations, the final say on the AH-X's performance and mission requirements will probably be determined by the availability of funds, say local sources. Rival Japanese manufacturers, as a result, are positioning themselves to respond with a choice of low and high cost options.

Fuji, with the support of trading house Mitsui, is keen to secure its attack helicopter production capability with the newly designated AH-1Z. The proposed twin General Electric T700-powered helicopter is based on the four blade AH-1W/4BW Super Cobra under development for the US Marines.

The company, at the same time, is believed to be in talks with Boeing to offer a locally built version of the more expensive AH-64D Apache Longbow. Fuji is also studying a Rolls-Royce Turboméca RTM322-powered version of the helicopter. A variant of the AH-64's T700 engine is produced under licence by Ishikaw- ajima-Harima Heavy Industries for the Mitsubishi/Sikorsky S-70.

Kawasaki is keen to enlist JGSDF support for developing an attack variant of its new tandem-seat OH-1 armed scout helicopter. Several options are under study to bolster the machine's performance, including fitting the helicopter with either the R-R/Turboméca/MTU MTR390 or LHTEC T800.

Replacement of the OH-1's twin 660kW (885shp) Mitsubishi XTS1-10 turboshafts with more powerful engines would probably entail further investment in developing a new gearbox.

The Eurocopter Tiger is seen as another possibility. Local industry sources suggest that Kawasaki's earlier collaboration with Eurocopter on the BK117 could open the door to possible further co-operation on the Tiger.

Source: Flight International