Zhuhai, Nov.04 (China Defense Mashup Report by Johnathan Weng) — Today Chinese Aero-Engine Manufacturer firstly opens the real face of Taihang (WS-10) Turbofan Engine in 2008 Zhuhai Airshow. From the picture, it can be seen that WS-10 is different with Russia’s AL-31F engine. In 2006 Zhuhai Airshow, a picture of WS-10 engine was once displayed in exhibition hall but removed later.

My Analysing Article About Taihang ( WS-10) Enginem, which was written in 2006

In November 2005, the official press of Chinese aviation Industry–Chinese Aviation Paper, released a group news, which disclosed that the first Made-in-China Turbofan had been successfully finalized the design. As the usual Chinese report rules on military equipments, no exact engine type was showed in media. In fact, this engine is WS-10 Turbofan (codename Taihang–A Mountain hill in North China) and its R&D time has been 20 years long. The emersion of WS-10 engine declares that China has owned the ability to manufacture advanced bypass engines for Chinese fighters without exporting from other countries like Russia. And the development history of WS-10 engine tells us the Chinese people’s great ambition in aviation industrial technologies, however, their road ahead is still long……

Beginning from WS-6

Telling story of WS-10 engine can not exclude the development of Chinese WS-6 Turbofan engine. WS-6 engine was once the first attempt of China in bypass engine manufacturing, it failed but it created the foundation of WS-10 engine. Many technicians involved in this project later all become the main forces of Taihang Project research.

In the 1960s, young People China just recovered from bloody civil war and Korea war. Chinese people established primary aviation industry by the captured Japan planes in Manchuria and help from CCCP. To China, Aircraft engine was like a high mountain to impossible overcome because of the so complicated machining technologies and advanced materials production. However, China never says gives up. In 1961, 606 Engine Design Institute was founded and it had begun to focus on the era’s most senior aircraft engine—-Turbofan engine. Under the direct order from General Chief Staff Gen. Luo Ruiqing, Chinese researchers began the preliminary technical preparation.

In May 1964, Chinese PLA Airforce announced to require a new fighter which was better than J-7 (Mig-21). Hereafter, Shenyang 601 Aircraft Design Institute and 606 Engine Design Institute cooperated to provide the plan. After the consultant between Airforce and industries, the new fighter would come out in two steps. One, to design a new frame with two improved turbines (it is the origin of J-8 fighter and WP-7A turbine engine); two, a whole new high altitude and high-speed interceptor equipped with a new afterburning turbofan. The serial code of the interceptor was J-9 and the new engine was WS-6.

The argumentation of WS-6 was finished in September 1965. May 1966, the project was turned into trial production. In June 1968, the first experimental WS-6 engine was test on platform. However, Cultural Revolution seriously interrupted the research of WS-6. In 1970, some PLA leaders required large jet transporters. For this difficult project, China began to get WS-6A engine from WS-6, which was using single stage fan and middle compressor. The airflow and bypass ratio increased and get off the afterburner. China produced 3 WS-6A engines. But the project was cancelled just because the jet airlift was too unpractical for Mao’s China. This improper behavior also diverse the research team of WS-6. Until October 1980, the performance of WS-6 had reached the design target. Then 24 months later, WS-6 passed the 24 hours preliminary flight rating test, PFRT. The whole testing time was totally 334 hours. In 1980, 606 Institute also designed WS-6G, an improved type of WS-6. This modified type has higher low pressure rotor speed, three-stage fan and higher turbine inlet temperature. And former cannular combustor of WS-6 was turned to annular combustor in WS-6G. Under the same size and lightening 100 kg from WS-6, WS-6G’s afterburning thrust raised 13.2% and thrust to weight ratio up 18.9%. In February 1982, WS-6G entered quasi demonstration engine test. The accomplishment of expected thrust proved the technical feasibility of WS-6G.

From 1965 to 1984, What Chinese people get is a semi-finished turbofan engine, which is still in 1960s. No flight-test and lots of works were waiting to be finished. Under the most optimistic estimation, WS-6 will be realized in later 1980s. As being a thrust to weight ration of 6, WS-6 is just a second-generation engine and has 30 years gap with USA and Russia.WS-6G’s thrust to weight ratio is 7 and its initial work just began in early 1980s. WS-6G’s technologies and high reliable materials were hardly resolved at that time. By China’s estimate, WS-6G was going to be finished in mid 1990s, but it still not a third generation aircraft engine which can not be applied with China’s next generation fighter (J-10). Besides, the WS-9 turbofan engine (Code Name: Qingling), a strypped-down of Britain’s 1970s product Spey MK 202, was being carried on and this project was finished in 2002. The copy of Spey MK 202 also tells a truth that the project of WS-6 and WS-6G are impossible missions.

The great successes of nuclear weapon and ballistic missile in 1960s make China overrate her technological ability. The decision-makers, supervisors and implementers of Chinese aviation industry were all lack of preparation of the hardship of aircraft engine manufacture. China’s aviation industrial plan is unprofessional, which has no solid industrial foundation and basic scientific research. Before 1980s, the aviation industries were shaken by political movements and post 1980s were impacted by military expenditure and projects shrink. All these factors lead one result: after 40 years, China in 1980s still was not able to develop a new aircraft engine independently.

The termination of WS-6 project was a rational measure. Then China halted the rough and tumble investment in aviation power industry. In a whole new door-opening condition, China started to import and learned engine technologies from foreign countries.

Core Engine of WS-10

The abandon of WS-6 project did do not mean that China gives up independent aircraft engine manufacture. In 1980, China started to implement a plan, High Performance Propulsion System Preliminary Development (HPPSPD), to focus on basic research on engine components. March 29th 1982, US famous “Aviation & Space Technology Week” had a report with title of “China Waiting for CFM-56II Turbofan Exportation”. The report said that China purchase 2 CFM-56II Turbofan engines to exchange China’s Trident airliners’ old ones. U.S. DOD (Department of Defense) worried about this exportation, because CFM-56 is based on the core of the F101-GE-102 engine which was used in B-1B Lancer Bomber. Despite of the dissidence, U.S. government still authorized this exportation in 1980s’ Sino-U.S. HoneyMoon Relation. Actually, some resources from China showed that the development of WS-10 just bases on the core engine from CFM-56. And WS-10′s final object, is F110 engine. WS-10 project got directly supports from top leader of China. In January 1986, Deng Xiaoping passed a new plan on China’s Turbofan engine development. One year later, 606 with its attached department formally initial the development of WS-10, code name Taihang, for China’s third generation fighter J-10.

In 1989, after almost 10 years’ preparation, WS-10′s core engine project started. June 12 1989, Chinese aircraft engine manufactures received the order of “3 core test components of HPPSPD ” In July, a conference of “Three most Important Parts of High Pressure compressor” was held in 624 institute. These three parts include: 7-stage high pressure compressor, short annular combustor with air blast atomizer and air film cooling blade. With out these main parts, China’s future core engine can not be resolved. In future, the core engine will be able to become a medial thrust & small bypass ratio turbofan which is 8 in thrust to weight ratio. In China aviation industry, this core engine was called as Medial Thrust Demonstration Turbofan Core Engine, MTDTCE.

At the end of 1990, MTDTCE entered the list of 18 Significant SciTech Projects of CSTIND (Commission of Science Technology and Industry for National Defense) ‘s Eighth-Five-Year Plan. In January 1991, the concept argumentation of MTDTCE and medial thrust demonstration engine had been completed. The whole plan conclude 3steps: step 1: High Pressure Compressor Components production; step 2, MTDTCE; step 3, demonstration engine. For the first time, China followed a regular way on engine development: basic research–technology break through–components–core engine–demonstration engine–prototype production. A milestone in China Aviation industry appeared in 1990s.

624 Institute designed the MTDTCE and the chief designer was Jiang Hefu. MTDTCE’ startup was in February 1991 and successively completed in preliminary design and main forgings and castings blueprints. In February 1992, major components machining blueprint was issued to sub-manufacturing plants. To speed the outside pipeline installation of core engine, a metal model of engine was finished in only 4 months.

The manufacturing of MTDTCE was carried by No.403 plant (military industrial plant all use code as name for confidential) and involved 21 factories and research departments in China. The trial production was initiated in March 1992. During the proceeding, 7 technologies were breakthrough by Chinese people, like complex directionally solidifies blade forging, short annular combustor manufacture, precision forging of diffuser with shaped blade and electron beam welding of compressor. China raises up its technology for 10 years. For 9 months (November 18^th, 1992), first finished product of MTDTCE was out of factory. After the installation of nozzle and accessories, the engine was fixed on the ground testing platform on November 24^th. On December 3^rd, PM 11:20, the engine was successfully powered on firstly. December 12^th, the eleventh test, the engine reached its maximum rotor speed and all testing parameters are normal.

However, the project of MTDTCE and WS-10 turned to be more confusing. According to China’s plan, the MTDTCE would bring a demonstration turbofan engine and then entered into the stage of WS-10 prototype production. But some research technicians of 624 institute once wrote that no demo engines came out. The main reason probably was “Tian-an-men Square Crisis” in 1989. After Chinese government’s bloody suppression on democratic movements and the end of cold war, the honey-moon Sino-US relation was over and western countries were united to establish hi-tech exportation border to China. WS-10’s object is F110, but then it was impossible in China’s hard international political circumstance. Shortly just after the success of core engine, however, 606 institute reported the airforce that a demonstration WS-10 engine was finished and could be installed with J-10 fighter in prototype research. How did this demo engine come out?

Here a clear explanation is necessary. We have known the WS-10 project belongs to 606 institute (the opening name is Shenyang Engine Design & Research Institute of AVIC I). And MTDTCE was designed by 624 institute (the opening name is China Gas Turbine Establishment of AVIC I). 606 has been focusing on military aircraft engine design and 624 institute is usually for advanced research of ship&aircraft using turbine engines. After the political crisis in 1989, China clearly understood the new situation and began to contact with Russia. China bought squadrons of Su-27 fighters and related assemble line for J-11 Fighter production. Meanwhile, Chinese people gained some AL-31F engines and hired some Russian engine experts. So the technicians from 624 institute said that no demo engine just for two possibilities. One is cheating propaganda. Many Chinese experts in military area will give some illusive information to media to cover the real things. Therefor, 624’s technicians knew the real steps of WS-10 but they hid the truth. Another possibility is the 606 institute directly use mass Russian staff in the demo engine to speed the WS-10 project. This demonstration engine of WS-10 had lots of AL-31F engine technologies and turned to be a “Hybrid” combined with U.S, Russian and China’s technologies.

An Unusual Sino-Russia Combination

Why 606 rushed the WS-10 project? Because WS-10 would have displeased the PLA Airforce. WS-10 was probably lost its “lover”. Since China had imported Su-27 fighters and WS-10 was so late to J-10 fighter, which then had to use a ready-to-wear turbofan engine—Russia’s AL-31F. 606 planned to use a J-10 fighter as a testing plane, but the airforce object 606’s appeal. The main reason is that J-10 is a single engine fighter and is in high risk when in WS-10 testing. Now WS-10 was just like its ancestor WS-6 and faced the same situation: no testing aircraft. At that time the Chief Designer of WS-10 was Zhang Enhe, who once participated the project of WS-6. To save the life of WS-10, he worked out a new proposition: using foreign fighter as substituted testing plane. In March 1993, 602 requisitioned to China Aviation Industrial Corporation (later divided into AVIC I and AVIC II) to provide a Su-27 fighter for WS-10 testing. At this time, WS-10 eventually got the support from leaders of PLA forces.

June 7^th 1995, Deputy Chief General Staff Cao Gangchuan (now minister of Defense Department) led naval and air senior generals and heads of CSTIND (Commission of Science Technology and Industry for National Defense) to 606 Institute. Chief designer Zhang Enhe made a proceeding report. On the report conference, Cao Gangchuan delivered an important message from CPC Military Commission. He said: “‘Taihang’ engine (WS-10) is designed for one new fighter (J-10) and as one imported fighter (Su-27 and its Chinese edition J-11) ‘s next generation engine. So the final result and development time of Taihang decide the success of China’s new fighter and imported fighter. It examines the good or bad sense of top decision-makers. If Taihang fails, it means the end of China’s future fighter. Leaders of PLA forces all make big mistakes. It is criminal of wasting people’s money. If so, we all will see each other in prison. Taihang engine is the extremely significant central part of Airforce’s future strategy. All people involved must understand their duties. ” Under the support and spurring of highest officials, a Su-27 was delivered for WS-10 development. But to put a WS-10 demonstration engine into Su-27 fighter is a fairly difficult course. WS-10, after all, was an engine designed for Su-27. The size of WS-10 is bigger than AL-31F’s, especially in oil tank and afterburner nozzle adjuster. Besides, the change of AL-31F was strictly limited. But the biggest thread to WS-10 was not the size, but the depression of China military Industries.

Since the reform and door-opening policy, China is always paying attention on economic growth. Despite the instructions from China leaders, WS-10 still starved for country’s investment. From 1992 to 1997, WS-10 project’s progress was unfavorable. In the same period, the state-owned enterprises in China, such as military industries, faced the utmost formidable economic shock. From the planned economy to market economy which was directed by Deng Xiaoping, the state owned facilities involved in WS-10 project lost of experts and experienced technicians. In 1997, China’s war industries have hit the ground and WS-10’s matching with Su-27 was also in hard time. This year when a WS-10 demonstration engine in ground testing, a serious accident took place that the blade of fourth-stage fan in high-pressure compressor broken. For 2 years, this problem was just solved. Before 1999, the 606 institute and manufacturer (Liyang Engine) merely proved that WS-10 could be used in Su-27 and the flight test schedule was unclear.

After US’ Bombing on China’s Embassy in Yugoslavia, however, all have been changed. China was extremely furious on losing face from U.S.’ behavior. The Chinese government admitted that U.S.’ military threads on China were real and concrete. So China’s investment on national defense stepped into a rapid growth period. Meanwhile, WS-10 project profited from it. About 2001 to 2002, WS-10 began the flight testing with Su-27 (J-11). In 2003, PLA Daily, official newspaper of PLA, had a report about WS-10 engine. It said: “Our new Turbofan engine is being tested on China’s new fighter (J-11)…the fighter is equipped with two different engines, one is made by China, the other is from foreign country.” This is the main evidence that WS-10 had been on critical developing stage since 2003.

Although WS-10 project got stronger support from government, it was still not smooth to excogitate Turbofan engine in developing country. And china defense enterprises were not recovery from the decline in 1980s and 1990s. Interior quality control and discursive employees often made WS-10 into great troubles. From August to September in 2003, WS-10 here and after performed some quality problems. In 2004, a fatal accident almost killed WS-10. At July 20^th 2004, a Su-27 fighter (test pilot Ding Sanxi) took off from Yanliang (in Shan’xi Province) Airport for WS-10 engine testing. When in flight testing, Ding Sanxi suddenly heard a “Bang”, then the left engine shut down. Pilot Ding Sanxi immediately judged that it was not like old in-flight shutdown accident. According to his experience, Pilot Ding Sanxi estimated that it was mechanical failure then he decidedly drove a single engine Su-27 to land on successfully. After four months’ investigation, the direct cause is the engine bearing failures. Since the beginning of WS-10 project, over 18 years have been passed and WS-10 had been troubled by bugs, from the mysterious sound to difficult starting in high temperature. To overcome these problems, Chinese people found ideas by their talents and even the bravery of test pilots.

WS-10’s Success: Just a Beginning

On May 11^th 2005, the endurance life test of WS-10 engine started in 606 institute, which declared that the project is close to the designed approval of prototype. This period includes two important test-operations: endurance life test and then full life test. In the history of China’s engine development, WS-10’s created a series of top records in testing range, programs and hours. Those two tests are the most rigorous trials on engine’s reliability. November 10^th 2005, WS-10 at last got across the full life test. WS-10 waltzed through 40 days’ trial without any failure. WS-10 project was finally finished after almost 20 years’ work. The supposed performance of WS-10 can be compared in the table in below.

According to resources from China, WS-10 engine can be described as follow:

It is a great power, high thrust to weight ratio and low bypass ratio engine with 12 stages structures, including 3-level fan, nine-level stator, one-level high pressure compressor and one low pressure compressor. For the development of WS-10, China makes almost 300 breakthroughs in aviation technologies and materials, like transonic turbine, air film cooling blade, integrated fan rotor by electron beam welding, squeeze film damper, metal brush seal, high energy igniter, variable camber inlet guide vanes and convergent—divergent nozzle. Especially the combined cooling blade of turbine used hi-tech materials called as Directionally Solidified Eutectic Super-alloy and can stand 5000 time tests without crackles.

In fact, the signification of WS-10 engine is beyond a mechanism, which is a usually simplified in western country. Five Permanent Countries of UN Security Council all have authorities to product and possess nuclear weapons. But there are only four powers which can independently manufacture modern turbofan for combat aircraft. The absent one is China. The birth of Ws-10 is a milestone that China has filled up the blank in fighter’s engine system. Production for nowaday generation, design for next generation and advanced research for future generation are running through the central line of China’s armament development history, so it is can be affirmed that China is developing the more powerful engine from WS-10 for a chrysalis—China’s fourth generation fighter, F-22 and F-35 made in China. At present, Russia’s new engine could not be realized for the atrophied economy. The well-known AL-31F is from Soviet’s foundation and notorious for low MBTF. UK plans to cooperate with U.S in F-119 engine which will be used in F-35. However, these two countries are in dispute for technology transformation. After the M-88-3 for Rafael, there are no engine development projects in France’s schedule. The fewer players in the fighter engine competition tell a truth that no one single country can endure the black hole of money and time for engine development. Russia, UK and France have to quit the game or cooperate with others. By holding abundant financing and advanced technologies, U.S. has been being the strongest player who is investing on future aviation engine, such as high-speed ramjet, variable cycle engine. Now a new player participate this expensive game. China’s GPD has been the 7^th in the world and its foreign exchange reserve has surpassed Japan and became the Top one. China’s air transport is growing in double number. Besides, China’s geopolitics condition, like in Korean peninsula and Taiwan Straight, was serious bad to breaking military conflicts in any moments. Therefor, China has motivation and power (money) to develop aviation engine from the strategic view. China and United States maybe the only two nations who provide more fund to engine projects. From WS-10 engine, the great ambitious strategy of China is so clear.

But China’s road to great engine manufacturer is still too long. To WS-10 here, whose thrust to weight ratio is likely under 8, it as a whole is better than AL-31F. Even the WS-10 catches up the F-110, it is still a product in 1980s’ level. China’s gap with U.S., remains in 20 years. In the production of materials for engine, China has countless problems to be solved. The more serious factor is from the unchanged disadvantages of China’s military industry. For the long “Shocking” time, rigidified managing structure and losing intelligence, the state owned military enterprises, comparing with Chinese private companies, were terrible in production efficiency and quality control. Several severe accidents were all caused by those soft spots. Although the investment growing after 1999, the state’s manufacturers need long time to become competitive enterprises. A military industrial journal, Aviation Engine, once published an article that there are totally 24 WS-10 demonstration engines after 15 years’ production in 2001, less two per year. It also said that the processing period of WS-10 first stage fan blade requires 10-12 months in China, and similar product only 6-8 months in Rolls-Royce. Even thought WS-10’s success is not propaganda trick, people have to doubt if Chinese enterprises can satisfy the need of PLA Airforce. In case China decides to enter mass-production, WS-10 possibly shows poor quality, otherwise shrinking performance. As a matter of fact, after the bearing failures accident in 2004, AVIC I Deputy General Manager Lin Zuoming who was in charge of WS-10 project, once told research staff to “produce an available WS-10 engine” to end this hard and long project. Perhaps, today’s WS-10 doesn’t have the expected performance and will be continuously improved.

China, however, is always having unbelievable changes in foreigner’s view. Chinese state owned manufacturers have lots of disadvantages, but they find ways to become contractors for oversea aviation giants, like Boeing and Airbus, and learn too much in project management. Besides, China armed forces now can open some equipment production to private companies, even some foreign registered companies owned by Chinese people. The significance of WS-10 which likes the China’s first Atomic Bomb in 1966 and just proved that China has ability to produce turbofan engine. If China can keep its economic growth and unswervingly invest on an opening and healthy aviation industry, her aviation engine manufacturing level will likely to exceed Russian, France and Germany, then narrow to tiny gap with United Stages in next 15 to 20 years.

Performance Comparison
Model Name	F100-PW-100	F110-GE-100	AL-31F	WS-10
Manufacturer	P&W	GE	Saturn	Liming Corporation
maximum thrust (daN)	10590	12268	12258	12500~13200
intermediate thrust (daN)	6520	7406	7620
turbine inlet temperature (K)	1643~1672	1644~1700	1685	1650~1750
Airflow (Kg/s)	101.1	113.4~122.4	112.0	~124.7
specific thrust (daN/ Kg/s)	~107	~108	~110	~106
thrust per frontal area (daN/ m2)	9369
afterburning fuel consumption (Kg/ daN·h)	2.31	2.01~2.05	2.0
intermediate fuel consumption (Kg/ daN·h)	0.72	0.70	0.795
thrust to weight ratio	7.7~7.8	7.07	7.14	7.5
bypass ratio	0.63 (0.60)	0.87	0.6 (0.571)	~0.78
total compressor pressure ratio	25	30.4	23.8	>30
fan pressure ratio	2.9	3.2	3.6	~3.3
high pressure compressor pressure ratio	8	9.7	6.46	12
compressor stage number	3F+10H	3F+9H	4F+9H	3F+9H
turbine stage number	2H+2L	1H+2L	1H+1L	1H+2L
main combustor style	Short annular combustor	Short annular combustor	annular combustor	Short annular combustor
afterburner

3200kgf Turbofan Engine

9500kgf Turbofan Engine

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200kgf Turbofan Engine