Japan's helicopter industry is only now beginning to come of age, with the development of its own indigenous designs

Paul Lewis/TOKYO

JAPAN'S AEROSPACE INDUSTRY lays claim to a rich and varied history of manufacturing helicopters, dating back more than 40 years. For the most part, however, this has consisted almost entirely of US models produced under licence by either Fuji, Kawasaki or Mitsubishi Heavy Industries. Japan's helicopter industry is only now beginning to come of age, with the development of its own indigenous designs.

First out of the home-grown design stable is the new military two-seat OH-X scout/ observation helicopter, developed by Kawasaki Heavy Industries (KHI) at a cost to date of '89 billion ($816 million). "This is an important programme for Japan and, at the same time, historically important to KHI, as it is our first indigenously developed helicopter," proclaims Kawasaki corporate executive managing director Ryozo Tsutsui.

For KHI, the roll-out of its first OH-X prototype earlier in the year was the culmination of more than four decades of helicopter manufacturing. The company first cut its teeth in 1952, assembling the Bell 47, and, by the close of production in 1975, had built close to 440 machines, including its own, improved four-seat KH4 version.

There then followed the Kawasaki/Vertol KV107 in 1963, with 160 -II and -IIA versions completed by the finish of production in 1990. KHI began licence manufacture of the Hughes OH-6 in 1967, and has since built 360 military and civil machines. KHI, therefore, considered it only fitting that it should be the prime contractor to develop a Japanese successor to the OH-6D scout.


"From the outset, we were very confident that this helicopter was within our technology level," says Tsutsui. "The OH-X is a very small helicopter and we have many years of experience, ranging from the heavyweight [Boeing] CH-47J Chinook down to the small Bell 47. We need always to take steady steps, and I didn't see any difficulties with this helicopter."

Development of the OH-X has included notable technological advances for the Japanese aerospace industry. The helicopter's ducted tail-rotor system with unevenly spaced blades, is claimed to be a world first, while its ducted tail, composite main-rotor blades and hingeless hub are all new areas of development for Japanese industry.

Many of the OH-X's components and systems were pre-tested - its hingeless rotor hub was fitted to a modified OH-6D for this. KHI's earlier involvement with MBB (now Eurocopter) of Germany, co-developing and producing the twin-engined BK117 civil helicopter, also provided engineering and technological experience, adds Tsutsui. A total of 106 Japanese-built machines have been delivered to date.


The OH-X should also provide KHI with a building block from which to pursue other future military and civil developments. The company's hingeless hub, fenestron-type tail rotor and full-authority digital engine-control (FADEC) system are likely to find future alternative applications. "From a business viewpoint, this latest helicopter technology is just a beginning and forms a good basis for future developments," suggests Tsutsui, refusing to disclose further details. "Let us complete this [OH-X] development 100% and then we can think about the future."

At the same time, Mitsubishi Heavy Industries (MHI) is forging ahead with its own in-house development, the twin-engined MH2000 civil helicopter. The ten-seat machine is scheduled to be rolled out privately by early August. Although the helicopter will not the first indigenous Japanese design into the air, it will be the first to be certificated by the Japan Civil Aviation Bureau (JCAB).

"We do not intend to claim to be the first indigenous manufacturer of a domestic helicopter. We feel that it is very difficult to design, develop and produce helicopters, and we have only experience of manufacturing helicopters under licence. But, in terms of actual volume of production and sales, we supersede that of Kawasaki," contends MHI managing director Takashi Nishioka.

MHI, like its rival, KHI, has been producing successive generations of US-designed helicopters for the Japanese military since the early 1950s. The Nagoya-based aerospace division hitched itself at an early stage to Sikorsky, starting with the licence manufacture of the HSS-2/S-61 anti-submarine and search-and-rescue helicopter and, more recently, its replacement SH-60J Seahawk naval and UH-60J/JA Black Hawk utility machines.


"What we wish for now is the capability to manufacture our own helicopters," says Nishioka. MHI accordingly launched a basic research and data-collection programme in 1992, using a heavily modified Sikorsky S-76 airframe. The RP-1 experimental helicopter project remained a closely guarded secret until shortly before its first flight in September 1994.

The helicopter served as a test vehicle for MHI's newly developed MG5 turboshaft engine, composite four-blade main rotor and transmission. The RP-1 completed 40 test flights by March 1995, at which stage it was decided to develop a machine for certification and commercial use.

"We came to the conclusion that we should go to the next stage in development," says Nishioka. MHI therefore launched its new MH2000 helicopter in April 1995. "Almost everything that we experienced in the RP-1 is reflected in the MH2000, including the engine, blades and gearbox," adds Nishioka.

The 4.5t helicopter is powered by two 595kW (800shp) MG5-100 turboshafts. The engine comes from the same basic MG5 family as the XTS1-10 military derivative installed in the OH-X. While the two powerplants share the same basic core, Nishioka is keen to emphasise that the MG5-100 is a "minimum-cost engine", with a different bill of material.

He adds that any cross-fertilisation between the OH-X and MH2000 helicopter stops there. MHI has developed its own composite blades and FADEC system, providing either high-speed or low-noise modes. Other noise-reduction features include an MHI-designed ducted tail, fitted with ten asymmetrically spaced composite blades, and cabin active-noise-suppression system.

MHI intends to offer a choice of avionics, but has not yet shortlisted any specific systems. It is instead waiting for prospective buyers to state their requirements before making a final off-the-shelf selection at the end of the year. Options will include a global-positioning-system-based collision-avoidance system and automatic flight-control system.

The timing of an avionics selection for the MH2000 characterises the conservative approach being taken by MHI. "Usually, you would have all the systems in place before approaching the customer," admits Nishioka, "but we're taking an incremental approach and we're only now at the stage of trying to get type certification." MHI is planning an 800h flight-test programme, using two prototype helicopters fitted with Rockwell- Collins avionics. An additional two static-test airframes are being used for load and tie-down tests, the first of which began in May. JCAB type certification is targeted for April 1997, with MHI hoping to deliver its first production helicopter the following September/October. Production of some long-lead components has already begun, says the company.

Its approach to marketing the helicopter is proving equally as cautious as the MH2000's development, with sales of just 200 machines projected over the next ten years. MHI initially plans to offer the MH2000 only to prospective Japanese corporate, airline and Government- agency operators. Once it has established a solid domestic base, MHI will then consider exporting the helicopter to Asia.

Its policy can be explained partially by the Japanese aerospace industry's lack of international marketing experience and uncertainty about how well the MH2000 will fare against US and European competition.

Japan's third major aerospace manufacturer is Fuji Heavy Industries (FHI). Like its two main counterparts, FHI has for many years been heavily engaged in the licence manufacture of US helicopters for the Japan Defence Agency (JDA). The company is hoping soon to diversify with new commercial products, the recently certificated Fuji-Bell 205B and new RPH2 remotely piloted helicopter.

The improved 205B is a further commercial development of Fuji's UH-1J utility helicopter, now in licence production for the Japan Ground Self-Defence Force. The 205B had its first flight in May 1995 and was certificated by the JCAB in early December. It is intended as a follow-on successor to the 204B4 (UH-1H) and even earlier 204B (UH-1B) models. Fuji aerospace commercial general manager Kisaburo Wani explains that the 205B offers an improved slung-load capability. It has been designed primarily for supporting construction work, such as the installation of electricity pylons, in mountainous areas of Japan. Two machines have already been delivered to two local operators Ace Helicopters and Asahi Koyo. The 205B can carry an underslung load up of to 2.3t, compared to the 204B2's limit of 1.8t. The 5t helicopter is also able to accommodate a heavier internal payload, while offering improved manoeuvrability and performance, particularly in hot-and-high environments. Fuji has also tried to cut maintenance costs, by extending the mean time between overhaul to 5,000h .

Principal changes include fitting an uprated 1,340kW (1,800shp) Kawasaki-built Textron Lycoming T53-17B turboshaft, adding an improved Bell 212-type main rotor and 960kW transmission.

Fuji's licence with Bell limits sales of the 205B to the Japanese domestic market, but Wani is nonetheless optimistic of a strong replacement-market. "We produced 50-60 204B [1963-74] and 204B2 [1974-91] helicopters and, with growth in the electricity market, we can expect to build more than that," he says.

Fuji's longer-term plans hinge on securing JDA funding for a UH-1J successor, smaller and, presumably, cheaper than the UH-60JA. It wants to develop an advanced medium-sized helicopter, incorporating new technology to reduce weight, maintenance time, noise and vibration. Basic research studies are already under way into new blade, bearing, transmission and composite-materials technology, says Wani.


Its second commercial venture is the RPH2 remotely piloted helicopter, being developed as a crop duster in conjunction with the Japan Agricultural Association. The 305kg machine had its first flight in February this year and is planned to enter service in 1998.

Wani explains that the RPH2 is intended to address the environmental problem of accurate, low-level dusting close to urban areas and in mountainous regions. He adds that the unmanned vehicle is meant to complement, rather than replace, manned crop-dusting helicopters and projects a requirement for up 50 machines a year.

To keep costs to a minimum, Fuji has used a 60kW Robin piston engine, produced by its industrial division to power the RPH2, while its controls are supplied by the company's automobile division. The vehicle will have a maximum payload of 100kg, including up to 60kg of chemical agent and 20kg of fuel for up to 1h of flying. Fuji estimates the RPH2 will cost between $140,000 and $200,000 a unit, depending on the equipment fitted.

Source: Flight International