Changhe Z-10

WZ-10
Two possible versions of the CAIC Z-10
Role	Attack helicopter
Manufacturer	Changhe Aircraft Industries Corporation (CAIC)
Designer	Wu Ximing
First flight	29 April 2003
Primary user	People's Liberation Army
Number built	6+

The WZ-10 (WZ, 武直 = Wuzhuang Zhishengji, 武装直升机, literally "Armed Helicopter") is an attack helicopter developed by the People's Republic of China. It is designed primarily for anti-tank missions but is believed to have a secondary air-to-air capability as well. It is being built by Changhe Aircraft Industries Corporation (CAIC).

Development

The origins of WZ-10 date as far back as 1979, when China began to explore ways of countering the advance of large enemy armour formations that would attack in great numbers. The resulting analysis by Chinese military establishments suggested that the most effective conventional way (i.e. without use of nuclear weaponry) was to attack enemy armour formations from the air and the attack helicopter was the best choice. Eight Aérospatiale Gazelle armed with Euromissile HOT were procured to further evaluate this option and the results lead to the birth of the WZ-10 project.

Early exploration

The resulting evaluation of modern warfare, with combined military arms, in the early to mid 1980s had revealed that the current armed helicopters in China's inventory no longer met the requirements of modern combat, because all of them were converted from civilian helicopters which made them vulnerable in intense combat situations. These civilian helicopters converted for military use could be used as scouts at best, it was found that facing off enemy armour formations required a dedicated attack helicopter such as the AH-1 Cobra or Mil Mi-24. As a result of these findings, the Chinese military evaluated the Agusta A129 Mangusta in the mid 1980s. In 1988 a defence agreement was signed between the USA and China authorising the sale of AH-1 Cobra attack helicopters to China, along with permission to produce the BGM-71 TOW in China under licence. But just as China was preparing to do further evaluations, China was sanctioned by the west after the Tiananmen Square protests of 1989. Afterwards, as China turned to Eastern European countries for help in the period between 1990 through 1991, the colour revolutions also prevented China from obtaining attack helicopters. As China attempted to import the Mil Mi-24 from Bulgaria and Russia, all of them rejected Chinese requests.

While attempting to import foreign attack helicopters resulted in failure, domestic research continued to reveal the shortcomings of China's current fleet of helicopters exposed by war games. The Chinese military had concluded that not only was the Chinese helicopter force inadequate, so was the structure of its armed force. In order to check large enemy armour formations successfully with attack helicopters, the helicopter force had to be under the command of the army instead of the air force. People's Liberation Army Ground Force Air Force (PLAGFAF) was established as a result and starting from a mere 9 Harbin Z-9, it would eventually expand to over 500 in the next two decades. More importantly, despite the lack of attack helicopters, research was continued and the PLAGFAF used other armed helicopters to simulate future attack helicopters, exploring tactics and strategies, helping to define the requirements for the future WZ-10. Equally important, extensive research work had revealed that missiles such as BGM-71 TOW were inadequate and the earlier proposal of a more powerful anti-tank missile such as AGM-114 Hellfire was once again proven to be in need. Such findings were fundamental for WZ-10 in that the entire weaponry and fire-control system would be centred on the new missile, setting the most important criteria for the future helicopter.

Dedicated research

The results of combat in the Gulf War made the Chinese military further realise the importance and the urgent need for attack helicopters. Based on their experience gained in operating armed helicopters, the Chinese military concluded that armed versions of the Changhe Z-11 and Harbin Z-9 could not meet their requirements and a dedicated attack helicopter was needed. In addition to being an effective anti-tank weapon, it also needed to be capable of defending itself against enemy helicopters and other aircraft. It was found that the most effective tactic would be deploying the new attack helicopter alongside the Changhe Z-11 or Harbin Z-9. The latter would serve as scouts, finding and designating targets for the former, while the former performed the actual attack missions on the enemy targets. The Chinese military recommended that in order to meet the requirements, the government should do two things. To meet requirements quickly, foreign attack helicopters should be purchased. In the mean time, an attack helicopter research team should be established to prepare the necessary research work on future domestic manufacturing and development of an indigenous attack helicopter. However, China's second attempt to procure attack helicopters failed. In 1994, a deal to introduce the Mil Mi-28 fell apart Russia rejected China's requirement to produce the Mi-28 in China under licence as in the case of the Sukhoi Su-27/Shenyang J-11.

The second approach had greater success. Sometime between 1990 and 1991, following the issue of recommendations by the Chinese military, China established the Armed Helicopter Developmental Work Team (武装直升机开发工作小组), consisting of members from various military and governmental organisations as well as scientific research establishments. The research work done by this team led to the recommendation that the new attack helicopter should not be based on the technologies of current Chinese light helicopters such as Z-11 or Z-9, but on a new medium helicopter design, which was also urgently required by China at the time. Since many helicopter technologies are shared by civilian and attack helicopter designs, it was suggested that it would be wise to hide the new attack helicopter program under a civilian medium helicopter development program. After the continuous failures in introducing heavier helicopters of foreign origin to China, the 6-ton class China Medium Helicopter (CHM) program was started in 1994 by China, with the 602nd and 608th Research Institutes as the leading designers. Under this ostensibly civilian program, various key western helicopter manufacturers provided considerable technical assistance to the later WZ-10 development program, including Eurocopter (rotor installation design consultancy), Pratt & Whitney Canada (PT6C turboshaft engine) and Agusta Westland (transmission). Meanwhile, China concentrated efforts on those areas where it could not obtain foreign help.

Separate project

In 1998, based on the results achieved by the Armed Helicopter Developmental Team achieved over the years, the 602nd Research Institute proposed to either separate the armed attack helicopter from the medium helicopter program or devote all resources to the armed helicopter program. The 602nd Research Institute proposed a dedicated attack helicopter design, designated WZ-10, an abbreviation of Wu Zhi (武直)-10. Some sources outside China had also referred to it as the Z-X armed helicopter. In the same year, the Chinese government gave the go-ahead for separating WZ-10 into an independent program but the medium helicopter program was not abandoned, it was continued on a much smaller scale while most resources were allocated to WZ-10. Since most of the technologies were to be shared by both anyway, the priority for the medium helicopter program was to first develop those technologies that could be used on both civilian and attack helicopter. Development of WZ-10 was given the name Special Armed Project (专武工程) by the Chinese government, a shorter form of Special Use Armed Helicopter Project (专用武装直升机工程).

The development of WZ-10 was under strict secrecy, more so than other secretive development programs such as the Chengdu J-10 combat aircraft. The Chinese government allocated nearly ¥ 4 billion as an initial investment and the WZ-10 became one of the most important aircraft programs begun in the 9th 5-yr plan. The 602nd Research Institute was assigned as the chief designer, while Harbin Aircraft Manufacturing Corporation (HAMC) of China Aviation Industry Corporation II (AVIC II) was assigned as the primary contractor of manufacturing. Nearly four dozen other establishments participated in the program. In the summer of 1999, AVIC II began to use a CAMC Z-8 to test newly developed WZ-10 sub-systems of WZ-10 and in autumn of the same year, a Harbin Z-9 was added to the test aircraft inventory. These tests concentrated on sub-systems such as the fire-control systems, HOTAS controls and navigation systems. Some foreign assistance from South Africa has been confirmed, which provided limited help in the area of flight stability based on the experience from designing the Denel AH-2 Rooivalk. South Africa refused further Chinese requests for assistance and no contact was made after 2001.

New manufacturer

In 2000, the Chinese again attempted to obtain a Russian attack helicopter, but the deal for the Kamov Ka-50 fell apart just as the Mil Mi-28 deal several years earlier. The repeated failures in obtaining foreign attack helicopters reinforced feelings that China had no choice but to ignore foreign options and develop its own such aircraft and work on the WZ-10 accelerated. In the same year, HAMC transferred most of its production responsibilities to CAIC of AVIC II. The official reason given was excessive workload; HAMC was busy producing the HC120 and Harbin Z-9, as well as other fixed wing aircraft such as the Harbin Y-12, and thus was stretched to the limit. However, many speculated that HAMC was not performing well enough due to rigid and ineffective Soviet-style management practices, believed to have caused the company to go into debt.

Although HAMC was in the process of reform, which finally succeeded, the government and military were weary and impatient. The SH-5 factory had become very profitable after its successful restructuring and reform, but it had to get out of the aircraft manufacturing business for good, manufacturing pressurized tanks and other specialized containers. It was decided that the WZ-10 program was too important to be run by HAMC, so a more stable contractor was sought and CAIC was selected. HAMC still retained responsibility for production of certain sub-systems and components, for which it could utilize experience gained from manufacturing parts for foreign helicopters and fixed wing aircraft such as the Embraer ERJ 145 family.

In May 2002, the WZ-10 tail rotor and some other components were tested on the ground by the 602nd Research Institute. In April 2003, a WZ-10 prototype completed its maiden flight at Lumeng (吕蒙) airfield, the airfield having been assigned to CAIC for such use. According to Chinese sources, the initial test flights were concluded on December 17, 2003, whereas according to other sources they were completed nine month earlier in March 2003. According to Jane's Information Group, a total of 3 prototypes had completed over 400 hours of test flights by this time. By 2004 3 more prototypes were built, for a total of 6, and a second stage of test flights were concluded on December 15, 2004. In one of the test flights the future commander-in-chief of the People's Liberation Army Ground Force Air Force (PLAGAF), Song Xiangsheng (宋湘生), was on board the prototype. A third stage of intensive test flights followed, taking place during both day and night. By January 2006 weaponry and sensor tests, including firing of live ammunition, were taking place.

Prototypes and a small number of pre-production aircraft are in service with the Chinese military for evaluation. The design is undergoing continuous minor modification and upgrade based on the feedback.

Design

The chief designer of WZ-10 is Mr. Wu Ximing (吴希明) of the 602nd Research Institute, one of the many top Chinese scientists play important roles in the 863 Program. Mr. Wu had participated in the designs of the armed version of transport helicopters Z-8A and WZ-9, and as the chief designer and project manager of WZ-10, he completed 5 years of work in just 2 years. WZ-10 is the first Chinese helicopter that eventually achieved paperless design, and the all electronic / online design enabled the design work to be completed within a year. In order to complete the necessary development, the 602nd Research Institute and CAIC had jointly built brand new engineering design center, industrial simulator, aircraft engine ground test center, fatigue laboratory, and full-scale rotary test platform (nicknamed as Iron Bird Platform, 铁鸟台). With the exception of the engineering design center, all of the rest facilities are claimed to be the largest of their kinds in Asia.

The new facilities had helped China to overcome many difficulties it faced in the development and since the end of 2001, the longest test was completed on the full-scale rotary test platform, paving the way for the future test flights. Composite material is widely used in the WZ-10 but China faced difficulties in this field, particularly in the area of survivability during crashes. Huge efforts were spent to domestically develop composite materials able to provide comparable levels of survivability to Western counterparts. This achievement earned a 2nd place in the Commission for Science, Technology and Industry for National Defense (COSTIND) progress reward.

Avionics (aircraft related)

The main contractor of the avionics of WZ-10 is the 613th Research Institute, which was responsible of integrating all of the avionics subsystems provided by subcontractors. Although foreign technologies are utilized (particularly French and Israeli, as rumored), this is limited to hardware only. All software applicable to WZ-10 are completely indigenously developed by China on its own. Reportedly, the most time consuming part of the software engineering for WZ-10 was to develop all of the mathematic models needed for WZ-10. Instead of using French standard DIGIBUS, WZ-10 is built to Chinese GJV289A standard, the Chinese equivalent of MIL-STD-1553B. The adaptation of western military standard means that western weaponry can be readily deployed on WZ-10, and the developer claims that all it needed was to add a module or interface to accomplish this. The ease of being compatible with multiple weaponry would also help to expand the export market of WZ-10 in the future.

Flight instrumentation

There are two configurations of the flight instrumentation for WZ-10, one developed from similar foreign system (rumored to be French), and the other one is indigenously developed, and both configurations share the same holographic head-up display. The difference in layout between the two configurations is that in one configuration, there are three color LCD multi-function displays (MFD), while the other, these are replaced by two larger LCD MFDs. It’s not clear which one is originated from foreign system and which is indigenously developed, but it’s reported that the practice of having different configurations thanks to the modular design is for export purposes, to fit the potential customer countries’ pilots’ habits. However, there is a rumor that China initially lacked the faith in its domestic system during the early stage of the development of WZ-10, due to the backward Chinese industrial capability at the time, so a backup was developed in parallel as a precaution, and the help to potential export resulted later was just a coincidence. A small number of mechanical dial indicators are also retained as a backup in case the MFDs have failed.

WZ-10 is also the very first indigenous Chinese helicopter that adopts HOTAS, but a traditional conventional control system had been developed in parallel as a backup, just as the case of cockpit MFDs, and for the exact same reason why two configurations of flight instrumentation were developed in parallel. The erroneous claim of installing Russian K-36/37 ejection seat in the cockpit of WZ-10 proved to be false, and the survival of pilots in emergencies landing depends on the crashworthiness of helicopter. To counter balance the weight of the armor protecting the pilots, flight instrumentation panel is the place where composite material is mostly used, as in the case of the dashboard of automobiles, where plastic material concentrates. One of the greatest challenges was to find the right composite material that is fit to use, while at the same time, also meets the safety standard so that during a fire, the pilots would not be knocked out by the toxic fume released by the burning composite material.

Navigation

Unlike previous Chinese helicopters which had different navigational systems onboard independently, the navigational systems of WZ-10 are fully integrated, and these includes a laser gyro, which will be replaced in the future by an optical fiber gyro currently under development, one becoming available. A radar altimeter currently installed on WZ-10 is full interchangeable with laser altimeter. Early units of WZ-10 has a pulse Doppler navigational radar which only had weather and navigational capabilities, and a more advanced (and thus more costly) model has been developed, incorporating ground mapping, terrain-avoidance and terrain following capabilities.

The onboard inertial navigation system (INS) is fully integrated with GPS/GLONASS system, and provisions are made for future upgrades to include Galileo (satellite navigation)/Beidou navigation system when expanded capabilities of these systems become available. For potential export customers, it can selection any satellite navigation systems of its choice, though GPS is usually the norm. In addition, despite developer’s claim of the navigational system of WZ-10 can utilize a variety of satellite navigation to improve its accuracy, the integrated GPS corrected INS is the only system that has been shown to the public at Zhuhai Airshows and other defense exhibitions. A modified Blue Sky navigation pod can also carried by WZ-10. Information is shared via secured data-link that provide real time and near real time information.

Avionics (mission related)

Electronic warfare

The electronic warfare (EW) system of WZ-10 is the first Chinese EW system that integrates the radar, radar warning receivers (RWR), laser warning receivers (LWR), electronic support measures (ESM) and electronic counter-measures (ECM) together. The system is designated YH-96 (YH = Yu Huo, 浴火), named after the YH radar. YH-96 is claimed to have a high interception rate of hostile signals, and in the fully automatic mode, it can automatically analyze the threat and launch different decoys and jamming signals accordingly. Alternatively, pilots can choose to launch decoys or jamming enemy sensors themselves.

Like the modified Blue Sky navigation pod, a modified BM/KG300G self protection jamming pod can also be carried, usually on one of the hard points of the stub wings. Similarly, a modified KZ900 reconnaissance pod can be carried for reconnaissance missions, although all of these additions come at the cost of reducing the number of hardpoints available for carrying weaponry. Usually, only one of such pod is carried at any one time. The identification friend or foe (IFF) system of WZ-10 is specially designed to work in an environment of heavy enemy jamming. All internally mounted jamming and decoy launching systems are built with the concept of modular design, so that they can be readily replaced when newer technologies become available.

Electro-optics (Optronics)

One of the two primary fire control system (FCS) is the electro-optical (optronics) system, which utilizes experience gained from earlier manufacturing of similar French and Israeli systems, combining the best of two, but only hardware wise. The software is completely indigenously developed by China on its own. The optronics FCS is manufactured by the 218th Factory of China North Industries Group Corp (中国兵器工业集团公司), a small and relatively unknown factory which was hidden in the busy commercial and residential area for more than four decades in the Chongwen Precinct of Beijing, until its relocation in the beginning of the 21st century. In the first decade of the 21st century, the 218th Factory would first expanded to form Beijing China Optical Instruments Ltd. (北京华北光学仪器有限公司), and later further expanded to China North Industries Group Corporation Elctro-Opticals Science & Technology Ltd. (中兵光电科技股份有限公司.) The chief designer was Dr. Li Baoping (李保平), who were transferred from the 203rd Research Institute in Xi'an to Beijing in 2001 to become the deputy bureau chief of the Electro-Optical Bureau of the China North Industries Group Corp, and at the same time, the project manager of optronics FCS of WZ-10. The next year, Dr. Li was named as the chief executive officer of the 218th Factory in addition, and under his leadership, the company not only developed the optronics FCS of WZ-10 during its rapid expansion, but also developed the primary weapon of WZ-10, the HJ-10 anti-tank missile. As a result of the success, the military sales of the company increased the original ¥ 30 million in 2003 to ¥ 20 billion in 2006. Many Chinese internet sources have claimed that although the great surge in the production of the optronics FCS & the primary weapon HJ-10 occurred in the first half of the first decade of the 21st century, the program actually had much longer time in existence, first in the form of research: research work in small increments had actually continued for decades, with origins dating back as early as early 1980’s. The optronics FCS of WZ-10 is named as Airborne Stabilized Aiming System (机载稳瞄系统) by China.

There are a total of four known types of optronics FCS that have been publicized, and all of them shares similar components for most parts. The common components of all three types include color daytime TV camera, night vision camera, imaging infrared camera. The only difference between the four known optronics FCS is in their laser targeting system. The earliest sample is the cheapest, with a laser range finder for HJ-8 and similar wire-guided missiles. A more advanced version appeared shortly after, with a laser range finding and targeting system for laser beam riding missiles such as HJ-9. The latest version currently in service has a laser ranger / designator for semi-active laser guided missiles such as HJ-9A and HJ-10. The most recent system that is currently under development incorporates a laser ranging / targeting system that can perform all of the functions previously handled by separate system, and this latest developmental type is also the most expensive and most bulky one of all. During the 10th 5-yr plan, the 602nd Research Institute was tasked to develop a mast-mounting system for the optronics FCS, which was successfully completed in 2003 (test flew on Harbin Z-9). The optronics FCS is fully compatible and can be slaved to the pilots’ HMS/HMD, and the seekers of the missiles can also be slaved to the FCS.

Helmet mounted targeting and night vision

In addition to the millimeter wave fire control radar and optronic FCS, pilots of WZ-10 has another FCS, the helmet mounted sight (HMS) designed by the 613th Research Institute. The HMS is standard for WZ-10, and it is fully integrated into the overall FCS. The HMS of WZ-10 is based on the earlier HMS used on WZ-9, which was first shown at the 5th Zhuhai Airshow held at the end of 2004. The photos of HMS of WZ-10 begun to appear on the Chinese website in 2008, and more information followed. At the 7th Zhuhai Airshow held at the end of 2008, the developer confirmed that the HMS is not only fully integrated into the FCS, but also integrated to onboard navigational system as well. Although the navigational info can be displayed on the MFD, pilots can also fly WZ-10 on their own, without using the navigational system onboard. This is achieved by using night vision goggles (NVG), which the HMS is fully compatible. The HMS of WZ-10 can control both the air-to-air and air-to-ground missiles, working in the exact same way 613th Research Institute’s HMS for jet fighters (which was first shown to the public at the very 1st Zhuihai Airshow in 1996).

Additionally, helmet mounted displays are also developed for WZ-10. Such HMD is similar to the Honeywell M142 Integrated Helmet and Display Sighting System (IHADSS) used on AH-64 Apache, with a small display screen mounted on the side of the helmet. It’s rumored that such HMD is LCD, but this cannot be confirmed, because the actual device has not been shown in public yet. The developer, however, did confirm that HMD is not standard because when this HMD is mounted, NVGs cannot be used, and similarly, when NVG is mounted, HMD cannot be used. It is also unclear whether NVG is standard or not, because all of the official photos of WZ-10 helmet released by the governmental sources do not shown NVGs attached, despite the developer’s claim of the helmet and HMS are fully compatible with NVGs. All of the publicized photos released by the official sources of the Chinese government have shown that the NVGs used WZ-10 (as well as other helicopters in Chinese service) are in the binocular form. As with the case of optronic FCS, NVGs of WZ-10 is developed based on experienced gained in manufacturing similar French and Israeli systems.

Radar

Despite the original plan, the millimeter wave (MMW) fire-control radar (FCR) is not standard for WZ-10, because the radar was not ready in time. The urgent need forced the early samples of WZ-10 to be evaluated without the planned radar, and it was only later did the radar become available. The MMW FCR for WZ-10 is developed by China Northern Electronic Co. (中国北方电子公司), a subsidiary of Norinco. This MMW FCR is fully solid state and fully digitized, weighing 69.5 kg, less than half of similar former Soviet system. In comparison, both the Russian Arabelet / FH-101 MMW FCR used on Kamov Ka-50N and the Ukrainian Khinzhal MMW FCR used on Mil Mi-28N weight around 150 kg. In contrast to Russian system that uses two antennas, the Chinese MMW FCR adopts western approach of using a single antenna, similar to AN/APG-78 used for AH-64D Apach Longbow. The radar is designated as YH, short for Yu Huo (浴火), meaning bathing in fire. YH MMW FCR is fully integrated with other subsystems of the onboard electronic warfare system, such as radar warning receivers (RWR), laser warning receivers (LWR), electronic support measures (ESM), and electronic countermeasures (ECM), with the entire EW system onboard WZ-10 named after the radar. Final radar deployment configuration has yet to be determined.

Cockpit

The stepped tandem cockpit houses two aviators - the gunner in front and the pilot in the back - as in the conventional layout of most attack helicopters. The flight control of both aviators serves to back each other up, and the pilot, who is also the team leader of the aircrew, may override the gunner’s commands. The bottom and sides of the cockpit are protected by composite armor, and so are the engines and the fuel tank located in the middle of the fuselage. It is rumored that titanium armor was developed for the WZ-10, but this had to be given up because of the weight. But this problem may be solved as more powerful engines become available in the future.

The canopy of the cockpit is specially treated to prevent glare from the sun, and, as an additional option, a tanned version is also available for camouflage purposes, though this is not standard. The bullet-proof glass of the canopy may be as thick as 38 millimeters, and is able to withstand direct hits from shrapnel and rounds fired from machine guns up to .50 caliber size.

Propulsion

Powerplant and auxiliary power unit

The modular design of WZ-10 enables it to adopt a number of turboshaft engines. However, the multiple choices of engines have much more to do with the inability of Chinese industry to provide the necessary power plants for WZ-10 in time than the success of modular design concept. At least three type of turboshaft engines have been successfully tested for WZ-10, all of them foreign built. Russian Klimov VK-2500 turboshaft engine that powers Mil Mi-17s sold to China is among the ones used, and so are the Pratt & Whitney Canada PT6C-67C that powers civilian helicopters of western origin in Chinese service. Ukrainian Motor-Sich TV3-117 that powers Mil Mi-28 has also successfully tested, and Ukrainians are helping Chinese to develop its own indigenous turboshaft engine. It’s rumored that European MTR390 that powers Eurocopter Tiger has also been selected, but this cannot be confirmed. Due to the delay in the developing of Chinese domestic engines, all prototypes and pre-production series of WZ-10 are powered by foreign engines.

The future, long-term engines for the WZ-10 will be the domestic WZ-9 (WZ = Wo Zhou, 涡轴), designed by the 602nd Research Institute, with Ukrainian and Russian assistance. The previously erroneous claim of WZ-9 being a Chinese version of MTR390 proved to be false, because according to the publicized official Chinese governmental technical documents, VK-2500, TV3-117 and PT6 are all classified as third generation turboshaft engines, a category Wozhou-9 belongs to, while MTR390 is classified as a fourth generation turboshaft engine. Wozhou-9 is the least powerful engine out of the five tested for WZ-10, but enjoys the advantage of lowest operational cost because there is no foreign built component. Furthermore, since it is 100% built in China, there are no political issues that would affect the purchase of vital parts. Wozhou (WZ)-9 is scheduled to enter full operational service by the end of 2009. The transmission system was developed with the help of Agusta Westland.

Specifications for Wo Zhou - 9 (涡轴-9) turboshaft engine currently under development:

• Power: 957 kW
• Fuel consumption: 0.311 kg/(kW·h)
• Pressure ratio: > 8
• Inlet temperature: 1355 degrees Celsius
• Power to weight ratio: 5.4

The auxiliary power unit (APU) of WZ-10 is centered on a brand new brushless DC electric motor designed by Huafeng Avionics (华烽航空电器) Co, a subsidiary of GAIC. The new electric motor is characterized by its low voltage, high power, high rpm, and stable current, and the entire development only took three months. In contrast to previous helicopter designs, the integrated APU also provides power to onboard avionics for WZ-10, where early designs had separately systems for starting the main engine and powering onboard avionics. Such system has never been used on Chinese helicopters before, and its adaptation on WZ-10 proved to be successful.

WZ-10 is not stealthy, but careful attentions have been given to reduce its electro-magnetic characteristics to reduce the probability of being detected. The planned procedure to reduce its radar cross section includes adopting radar absorbent paints. Another planned measure is to incorporate laser altimeter pioneered by Israel, which would reduce the probability of intercept by enemy’s electronic support measures in comparison to traditional radar altimeter, which emits radio/radar signals, while laser is far less prone to interception. Chinese have claimed that the avionics of WZ-10 is more advanced that of Russian attack helicopters, and the avionics suit enables WZ-10 to be able to conduct mission at a level that is just 10 meters above the ground.

Rotors

The main rotor is mounted in the midsection of the fuselage, consisted of a total of five blades. From 1994 through 2001, the deputy chief engineer of CAIC, Mr. Li Meng (李萌) led the team to successfully develop the main rotor for WZ-10, winning two patents in the process. The main rotor blade, Type 95KT composite rotor blade was a top priority of the 8th 5-yr plan that first begun in that era, and it was one of the ten critical technologies of WZ-10. China never had such advanced technology and Mr. Li Meng had to lead his team to develop it on their own, and finished the job ahead of schedule. The early successful completion not only enabled WZ-10 to fly a full year ahead of the schedule, but Type 95KT blades have also been widely used afterward in new helicopters and upgrading old helicopters.

Type 95KT foamed composite blade requires many new manufacturing technique that previously did not exist in China, including: the soaking of the prefabricated material in special solutions under medium temperature, foaming of the carbon fiber and glass fiber composite material, solidification process of the foaming material, adding composite skin layers, and mathematical models for predicting the thermal expansion of the molds used for composite materials. Mr. Li Meng and his team made breakthroughs in all of these area and with the new techniques they developed, the production was greatly improved, with the energy cost reduced by 90%, production cycles shortened by more than five sixth, and molds needed reduced by five sixth also. China has claimed that these breakthroughs enabled Chinese productivity to reach its western counterparts. In addition to the composite material, there are four titanium alloy layers on the leading edge of every blade.

Based on the success of Harbin Z-9 and HC120, fenestron configuration was originally adopted for the tail rotor. However, due to the inherit disadvantages of the design, such as higher power requirement, higher construction and maintenance cost, higher resistance and weight, fenestron design was dropped after test flights, and a more conventional tail rotor configuration was adopted. The 4-blade tail rotor utilizes the similar to the tail rotor of AH-64, with two pairs at unequal distance instead of 4 blades at the equal distance, and one of the main purposes of such arrangement was to reduce noise. The tail rotor blades are consisted of a total of 11 layers of glass-reinforced plastic and composite material, enable them to sustain direct bullet hits.

Weaponry

Due to its modular design concept, WZ-10 can be armed with a wide variety of weaponry. The adaptation of Chinese GJV289A standard, the Chinese equivalent of the MIL-STD-1553B databus architecture, enables weaponry of both Soviet and western origin to be adopted by WZ-10. Offensive weaponry consists of machine guns, cannons, rockets and missiles. The stub wings have two hardpoints each for a total of four, each hardpoint being able to carry up to 4 missiles for a total of up to 16.

Cannon and machine guns

Internal armament consists of a gun mount installed on the chin of the aircraft (likely to be of 30mm calibre). Two stub wings provide attachment points for external ordnance or gun pods. The guns are mounted either in the chain gun form, or in the turret. All guns on the WZ-10 can be used either against ground targets or aerial targets, and can be directly aimed by pilots’ HMS. In the turret form, automatic grenade launcher can also be housed next to the machine gun in the same turret.

Three types of chain-fed autocannons are available for WZ-10, with the first being a 23 mm automatic chain gun indigenously developed by China. Like all other chain guns, this 23 mm gun covers a sector of 130 degrees. The largest caliber of chain gun carried by WZ-10 is a 30 mm automatic gun, a Chinese development of the Russian 2A72 autocannon for aircraft use. One of the primary reasons to adopt the 2A72 30 mm gun for aerial use is its high reliability, and according to Russian claim, the failure rate of 2A72 is nearly zero. Another important reason for developing an aerial version of the 2A72 30 mm gun is to simplify logistics. Older 30 mm guns used on fighter jets such as Shenyang J-6 is not compatible with ground and naval guns of the same caliber, and using the same ammo for air, ground and naval guns with the same caliber would greatly reduce the operational cost.

The most powerful autocannon that can be mounted on the WZ-10 is the Chinese reverse-engineered 25 mm M242 Bushmaster adopted for helicopter use. Originally mounted on the NVH-4 derivative of Type 85 AFV, the Chinese military was thoroughly impressed with its performance and modified the gun for aerial use. According to Chinese claims, the 25 mm M242 Bushmaster is the most accurate among all three autocannons of its kind in use with the Chinese military, in both ground and aerial formats. Furthermore, it is also said to be the most lethal of all, having the greatest penetrating power against armored vehicles. However, this gun is the most complex and thus the most costly, while being the least reliable type of chain-fed gun in use with the military. The relatively low reliability of the 25 mm autocannon also has prevented the ground version form being widely adopted.

Guns for WZ-10 can also be mounted in the turret form, but this is limited to small caliber machine guns. The largest type of machine gun that may be fitted to the WZ-10 turret is a single 14.5 mm gatling gun, while the smaller caliber 12.7 mm or 7.62 mm machine guns may be mounted either in single barrel or twin barrel forms. When armed with these smaller caliber machine guns, the coverage is increased to 180 degrees as opposed to the 130 degrees of larger caliber autocannons.

The turret is flexible enough to incorporate configurations such as a single barrel machine gun and an automatic grenade launcher with calibers ranging from 30 mm to 40 mm, as in the AH-1 Cobra. Grenade launchers are only effective against ground targets, while machine guns may be effectively used on both ground and air targets.

Guided and unguided missiles

The air-to-surface missiles deployed by WZ-10 include the domestic HJ-8, HJ-9 and HJ-10 anti-tank missiles. The HJ-10 is thought to be similar to AGM-114 Hellfire and it has an anti-helicopter capability in addition to anti-tank capability.

The main air-to-air missile deployed by WZ-10 is TY-90, a missile specifically designed for use by helicopters in aerial combat. TY-90 is claimed to have greater lethality than the MANPAD missiles usually carried by helicopters. The Chinese FN-6 and QW series missiles can also be deployed, as with other non-Chinese MANPADs. TY-90 and MANPADs are often carried in pairs, with a total of 4 carried. When using larger air-to-air missiles such as PL-9 or similar missiles such as AIM-9 Sidewinder, the total number is reduced to 2.

WZ-10 can be armed with a wide variety of unguided rockets ranging from 20 mm to 130 mm caliber. The largest rockets tested were a type of 130 mm rocket that were carried on the hardpoints just as missiles are carried, while smaller caliber rockets were mounted in conventional rocket pods. The most frequently used rockets are those ranging from 57 mm to 90 mm and a total of 4 pods can be carried under the stub wings, one under each hardpoint.

Operators

People's Republic of China

• People's Liberation Army

Specifications (estimated)

Data from jczs

General characteristics

• Crew: 2

Performance

• Thrust/weight: *Maximum acceleration: +3 g (29 m/s²)

Armament

• Guns: 23 mm or 30 mm autocannon mounted on chin turret with grenade launchers, or 14.5 mm Gatling gun
• Hardpoints: 4
• Rockets: 57 mm, 90 mm multi-barrel unguided rocket pods
• Missiles:
  
• Up to 8 ATGM air-to-surface missiles
• Up to 8 TY-90 air-to-air missiles
• Up to 4 PL-5, PL-7, PL-9 air-to-air missiles

Avionics

• YH millimetre-wave fire-control radar
• YH-96 electronic warfare suite

See also

Aircraft of comparable role, configuration, and era

• Agusta A129 Mangusta
• AH-64 Apache
• Denel AH-2 Rooivalk
• Eurocopter Tiger
• HAL Light Combat Helicopter

Related lists

• List of helicopters

External links

• GlobalSecurity.org
• SinoDefence.com report