NICK FARINA / LONDON
AVIC II is developing a next-generation helicopter to meet the growing demands of the country's military and civil sectors
For a country similar in geographical size to the USA, China operates comparatively few helicopters - barely more than 560 machines at the last estimate - most of them manufactured abroad, many of the rest built locally under licence. But with demand growing in both the military and civil sectors, change is on the horizon for China's relatively small indigenous helicopter industry.
The China Aviation Industry II (AVIC II) group, which includes helicopter manufacturers Changhe Aircraft Industries (CHAIG) and Harbin Aircraft Industry (HAIG), has a long-term strategy to meet future demand with products developed locally with the help of international partners. The centrepiece of AVIC II's strategy is the development of a family of 5/6t (11,000-13,000lb) rotorcraft that could include the long-rumoured Z-10 attack helicopter.
Reverse engineered
China has a long history of involvement with the European helicopter industry. Changhe still builds a locally developed version of the Aerospatiale SA321 Super Frelon as the Z-8 medium transport helicopter, while its light utility Z-11 - although claimed to be the first Chinese-developed helicopter - is a reverse-engineered version of Eurocopter's single-turbine AS350 Ecureuil/Fennec family. Harbin's Z-9 Haitun multipurpose intermediate twin-turbine helicopter, meanwhile, is a licence-built Eurocopter AS365N Dauphin.
AVIC II's 5/6t-helicopter programme was launched in 1995 and, although few details are yet available, it represents a significant departure from China's previous product strategies. Chinese industry clearly recognised that, to accelerate its development and increase its capability, a new strategy was required to eliminate the time-consuming and inefficient reverse engineering practices of the past, together with the continuing high cost of licence manufacture.
One of the wider industry trends recognised by China is that of co-operative development, which offers a number of potential benefits while promising to reduce the cost of fielding new products. AVIC II decided to exploit this trend at least partially for its new helicopter programme. But despite the decision to involve foreign partners in development of the 5/6t rotorcraft family, China's continued secrecy about the programme leaves many questions unanswered.
Multipurpose machine
AVIC II's principal objective with the 5/6t helicopter is to meet a range of military and civil requirements with one basic design. The programme aims to develop a family of next-generation rotorcraft with identical dynamic systems, potentially with a choice of turboshaft engines depending on the model and mission. The programme has three potential products:
a baseline 5,500kg Chinese Medium Helicopter (CMH) tactical transport for army aviation;
a 6,000kg third-generation attack helicopter, also for army aviation; and
a 5,000-6,000kg CMH commercial transport derivative, with growth potential.
China has never completed development of a new rotor system and this lack of experience, coupled with its limited knowledge of helicopter aerodynamics and of key materials and technologies, meant it planned from the outset to develop the rotor system with an international partner under the principle of "self-development first, co-operative development second".
In May 1997 AVIC/China National Helicopter Corporation (a predecessor to AVIC II) and China National Aero-Technology Import-Export Corporation (CATIC) signed a $70-80 million contract with Eurocopter France to develop an appropriate rotor system.
First details
In March 1999 Agusta announced it, too, had signed a $30 million initial contract with AVIC II and CATIC, this time to develop the transmission system for the Chinese Medium Helicopter - marking the first public reference to the CMH. While Eurocopter is responsible for the main and tail rotor hubs and blades, Agusta is working on the drive system, including gearboxes and transmission components.
A powerplant has yet to be selected, apparently, although two development Pratt & Whitney Canada PT6C-67C turboshafts were delivered to China's Helicopter Research and Development Institute (CHRDI) helicopter research and development institute in Jingdezhen last year. CHRDI is responsible for rotorcraft design and development in China. A number of CMH engine options have been examined, but attention has focused on the 1,250kW (1,700shp) P&WC engine as it has favourable hot-and-high performance and a better time between overhaul (5,000h) than some competitors.
Turbomeca has also offered at least one unspecified powerplant, and its new 900kW-class Ardiden turboshaft, specifically designed for 5/6t helicopters and expected to be certificated in 2005, could be considered for later CMH variants.
Agusta's collaboration in the 5/6t helicopter programme is not confined to development of drive system hardware. In July 2000 the company announced it had signed an agreement with AVIC II to significantly expand its role to include providing design expertise in unspecified areas related to the CMH, including support for re-engining the helicopter.
Engine selection
This suggests CHRDI may have previously selected an engine, but subsequently arrived at a different conclusion, potentially with Agusta's input. The Italian manufacturer, which is developing the 6,000kg-class, PT6C-67C-powered AB139 helicopter, may be advising CHRDI on the final choice of CMH powerplant.
AVIC II and CHRDI met Eurocopter personnel in Jingdezhen in late November last year to review the European company's progress. Eurocopter presented a status report on rotor system design, addressing issues related to its laboratory tests and initial acceptance checks. Outstanding technical challenges, as well as arrangements for the next development phase, were also discussed. The Chinese teams were satisfied that Eurocopter's rotor system, testing and other components will meet the technical requirements stipulated in the development contract.
Agusta's drive system work also appears to be proceeding well. The Italian manufacturer's gearbox and transmission experience is well established and China's tactical transport and attack helicopter requirements are likely to demand a drive system with performance exceeding that of every other Chinese helicopter type by a wide margin.
Despite the obvious cost benefits of commonality, few manufacturers have successfully developed both tactical transport and dedicated attack helicopters sharing truly identical dynamic systems. Rotor systems are designed to meet specific missions - taking into account time spent in the hover, as well as in forward flight at both low and high speeds - and it is safe to assume considerable effort has been spent defining the mission profiles for the tactical transport and attack helicopter. It is likely the attack variant will have different engines to those of the CMH.
Commonality benefits
Analysis suggests the first flight of a CMH prototype is feasible in in 2005 or 2006. This could lead to Chinese certification of a civil variant by 2007. First deliveries of the CMH tactical transport to army aviation could occur by 2012. Given its different mission and technical challenges, and the general lack of information, it is difficult to assess when the attack helicopter could fly, but production of both versions is expected to be under way by early in the next decade.
As China's single largest operator of helicopters, army aviation is likely to acquire a substantial number of CMH tactical transports, which will form a centrepiece of its force modernisation in the long term. While AVIC II's plans are focused mainly on meeting local demand, future activity in foreign markets cannot be ruled out. Given China's desire to strengthen its image as a helicopter manufacturer, and building on the recent export of Z-9As, it is conceivable AVIC II's CMH could find overseas customers.
Western attention has focused on the proposed attack helicopter, few details of which are available because of China's perennial national security concerns and Beijing's particular sensitivity about the machine's intended missions. Although AVIC II is working with European partners on the common dynamic system, it has not sought outside help with the mission system. This decision may assure tighter security, but has denied China access to Western combat helicopter expertise.
Attack effectiveness
This could call into question China's ability to use the machine effectively once it is developed, as the acquisition of data on the battlefield, and its processing, management and exploitation, are as crucial to fighting and winning future conflicts as the basic airframe's dynamic capabilities. China will have to develop doctrine and tactics for the effective use of a dedicated attack helicopter and decide how it will operate with other army aviation equipment and the army's land-warfare assets.
While the attack helicopter that eventually emerges from the AVIC II programme may not be leading-edge by Western standards, it is reasonable to assume its capabilities will be superior to those of its Chinese predecessors.
And, while the eventual aircraft may still fall short of requirements, it will probably play a significant role in army aviation modernisation and force capabilities.
Source: Flight International
