Japanese industry still harbours ambitions to develop an entire commercial jet, not just its components


Aerospace manufacturers in Japan have made great strides in recent years in developing their capabilities as risk-sharing partners and major subcontractors on Western aircraft programmes, but efforts to co-lead development of a commercial jet have been consistently thwarted by the market.

Past failures include the 7J7 project with Boeing, in which Japan was to have been a 25% shareholder. After eight years on the drawing board, the 7J7 project was finally abandoned in 1994after it became clear that low fuel prices were rendering propfan-powered aircraft unattractive to airlines, and Boeing meanwhile had launched its Next Generation 737 family.

The focus of Japan's civil aerospace research and development thrust is now the YSX, envisaged as a family of large regional jets seating between 80 and 110 passengers. Also on the drawing board is a smaller regional aircraft, the Asian Community Airplane. Meanwhile, Japan continues to work on technologies aimed at reducing the environmental impact of a future supersonic transport.

Japan Aircraft Development (JADC), which is responsible for distributing government funding for civil aerospace worth $30 million a year, is attempting to tailor industrial research work to fill the remaining gaps in the country's capabilities.

The idea is that Japanese manufacturers build on their skills as suppliers of major aircraft subassemblies - such as fuselages, wings and cockpit sections - to eventually lead to the development of an aircraft such as the YSX, and later to a smaller regional jet or even a large airliner. The goal is seen as a natural progression for Japanese industry in advancing from its status of a component supplier.

Kawasaki Heavy Industries recently won a contract from Embraer to make the wing for the ERJ-190 regional airliner. It already makes the wingbox and leading and trailing edges for the smaller ERJ-170 wing.

Meanwhile, the country has a 15% share in Boeing's 767 widebody twin, which entered service in 1982, and for which Japanese industry produces body panels, the wing-to-body fairing, wing ribs and doors. Its 21% stake in Boeing's 777 covers making similar components, as well as the wing centre section.

The YSX studies centre on advanced flight control and cockpit systems; nose, cockpit and wing structures; and next-generation avionics systems. The aim is to produce an aircraft with dramatically fewer parts and lower production and operating costs, compared with other regional jets.

Still at the feasibility stage, the YSX is envisaged as a three- or four-member family of regional twinjets powered by Pratt &Whitney PW6000 or Rolls-Royce BR715 engines. Configuration studies are being carried out in partnership with Boeing.

JADC managing director Masaomi Kadoya emphasises that the agency iscarrying out a "wide range of feasibility studies for the future aircraft" and that Boeing is "only one of the candidates for a future partnership among many possibilities". The business arrangement policy has not yet been decided.

However, the waters seem to have been muddied by Boeing's recent decision to sign an agreement with Russian industry to study the joint development of a family of regional jets. Furthermore, the business case for the US manufacturer entering the already crowded sub-100 seat market, especially given its lack of sales success with the 717, appears marginal at best.

Kadoya argues that the YSX can be competitive because of its low costs, and that it is still a viable proposition for Japan to share in a market expected to absorb 4,000 aircraft over the next 20 years, according to JADC forecasts. YSX-related research and development work continues unabated.

Innovative structures

A key element is the five-year NEDO project. This is aimed at developing innovative aerostructures for use in aircraft such as the YSX. Targets include significant parts-count and weight reductions for the cockpit structure and wing leading edge and centre box.

A large number of parts is required to build up the multi-frame cockpit structures of conventional aircraft, but JADC is studying whether the use of carbon fibre- reinforced sandwich skin panels and new casting and welding techniques can eliminate many of the frames and stringers. The forward pressure bulkhead, for example, could be attached to a large, thin, pressurised floor casting by friction stir welding.

A recent JSDC study paper says that reducing parts count is "the most effective way to reduce costs. It cuts working time for fabrication, assembly and processing".

"Generic wing and nose sections are being designed to demonstrate the advantages of the lightweight structural technology. Finally we will do the structural tests," says Kadoya. "We will make real wing and cockpit structures and substantiate the airworthiness requirements," he adds.

Another five-year project, which got under way in 1999, is known as "Aircraft with Advanced Systems" (ASYS), and under which an advanced cockpit and aircraft control system are being developed. The novel control system aims to provide an element of envelope protection but using conventional, mechanical linkages.

"We think we can fly these small aircraft with a very conventional flight control system, but adding some special devices to assist with control," says Kadoya.

A three-year next-generation avionics technology study was launched last year to investigate the integration of avionics for future air navigation systems, develop a synthetic vision system for use by pilots in low visibility conditions and build a fibre-optic "fly-by-light" flight control system that will be less susceptible to electromagnetic interference than conventional designs. JADC has invited several Japanese electronics companies to join this project.

Meanwhile, despite the lack of enthusiasm within the industry worldwide for next-generation supersonic transport (SST) work, Japan continues to sink significant amounts of money into SST-related studies. This year JADC is concentrating on airframe and systems integration technology under contract to the Society of Japanese Aerospace Companies, and on a project to reduce the environmental impact of future SST powerplants.

The agency also has a contract to study advanced heat-resistant composite materials and their application in SSTs from Japan's Research and Development Institute for Metals and Composites for Future Industries.

"We believe this kind of fast aircraft will be realised in the future so we should develop high-temperature structural technologies," says Kadoya. "We are doing SST configuration studies and marketing - these kinds of very basic studies."

A five-year project to research and develop an Environmentally Compatible Propulsion System for a Next Generation Supersonic Transport (ESPR) started in January. The target is a 25% reduction in CO2 emissions, NOx emissions limited to 5g per kg of fuel burned during cruise, and noise reduction sufficient to meet Stage 3 standards. The ESPR consortium includes all of Japan's major engine companies and research establishments, plus General Electric, Pratt & Whitney, Rolls-Royce and Snecma. It ambitiously aims to produce a demonstration engine in 2003.

The CO2 reduction would be achieved by deploying advanced materials to reduce weight and allow combustion temperatures to be raised, and by developing a complex engine control system to maximise fuel efficiency. Development of a "lean pre-mixed pre-vapourised" combustor with a composite liner plus "intelligent combustion control" would reduce NOx.

Noise reduction work is focused on advanced low-noise aerodynamics and noise attenuation technology.

Sonic cruiser

With any potential SST project clearly a long way off, Japanese industry has shown strong enthusiasm for the plans of long-time partner Boeing to develop its proposed high-speed sonic cruiser family.

Japanese Aircraft Industry (JAI), a consortium of Kawasaki, Mitsubishi and Fuji Heavy Industries, ShinMaywa Industries and Japan Aircraft Manufacturing, is interested in signing a memorandum of understanding (MoU) with Boeing to participate in the sonic cruiser feasibility studies and could eventually take up to a 25% risk-sharing stake in the programme.

However, industry sources say the talks between JAI and Boeing are at an early stage and the MoU is likely to take several more months to negotiate.

"We would like to sign the MoU as soon as possible," says one Japanese industry source, adding that options under discussion include sending a team of Japanese engineers to Boeing's design offices in Seattle or transferring some of the feasibility work to Japan. Others are more cautious, describing the Japanese proposals as a "wish list", but believing that co-operation "could ultimately go that route".

A partnership with Boeing on the sonic cruiser may be the most significant civil project on the horizon for Japanese industry. An opportunity to enter the lower end of the market with an all-Japanese product appears as elusive as ever.

Source: Flight International