Nanchang Q-6
Encyclopedia
The Nanchang Q-6 is a cancelled ground attack aircraft of the People's Republic of China
(PRC), with the Nanchang
Aircraft Factory (later reorganized into Hongdu Aviation Industry Group) as the prime contractor. The project never went beyond the prototype stage, despite a prolonged development.
(PLAAF) and People's Liberation Army Naval Air Force
(PLANAF) proved incapable of ground support missions. Although the South Vietnamese claimed that the People's Liberation Army
(PLA) had bombed the South Vietnamese forces on the three disputed islands, this was in fact not true. In reality, despite the Chinese intent to do so with the deployment of 115 aircraft which flew 401 sorties in support of the battle, none of the Chinese aircraft deployed actually attacked enemy positions.
Due to the lack of modern avionics and ground infrastructure to support a modern air war, Chinese aircraft suffered navigation and other logistics problems that severely limited their performance. The first Chinese aircraft not actually reaching the islands until several hours after the battle was over. In addition to the need to upgrade its logistics capability and infrastructure, China also decided that nothing in its then aircraft inventory could fill the requirement for support missions in the South China Sea
. Fighters such as the J-5
, J-6
, J-7
, and J-8
lacked a ground attack capability and were hamperes by short range. The only Chinese ground attack aircraft Nanchang Q-5
was also short ranged and had a low payload. China's bombers such as the Harbin H-5 and Xian H-6
were slow and lacked a self defense capability. A new aircraft was therefore seen as desperately needed to fulfill a new naval strike mission in support of the People's Liberation Army Navy
(PLAN).
Immediately after the battle, both the PLAAF and PLAN submitted their requirements for a new fighter bomber/ground attack aircraft to the 3rd Ministry of PRC. After extensive research, the 3rd Ministry decided that based on the Chinese aeronautical industrial capability at the time, it was impossible to develop two separate airplanes at the same time. Instead, a decision was made to develop a single airplane with different versions tailored to meet the different needs of PLAAF and PLAN, especially when the prime requirements of the PLAAF and PLAN were similar.
In June 1976, representatives from various aircraft factories were summoned to Beijing
to discuss the project, and were instructed to come up with designs in the shortest possible time. Shenyang
Aircraft Factory (later reorganized into Shenyang Aircraft Corporation
) was the first to come up with a design, the JH-8 (FB-8), which was essentially a ground attack version of J-8II (F-8II). This was followed by the Q-6 a new design from the Nanchang
Aircraft Factory. The Xi'an
Aircraft Factory (later reorganized into Xi'an Aircraft Industrial Corporation
) was the last one to present a design, the Xian JH-7
, also a new design. Initially, the 3rd Ministry favored the JH-8, however because the design of the J-8II was still not completed the risk was considered to be too high, it was eliminated. The projected development of JH-7 was too far out, and so the Q-6 was selected because it was believed to be the one that would be able for service the soonest.
, a few downed F-111 were also provided to China by North Vietnam. Based on the research effort performed on these aircraft, it was suggested that the variable-sweep wing should be adopted for the next Chinese ground attack aircraft. The general designer of Nanchang Q-5
, and the future academician of the Chinese Academy of Sciences
(elected in 1995), Mr. Lu Xiaopeng (陆孝彭), was named as the general designer of Q-6. Lu personally visited PLAAF and PLAN numerous times to obtain their input, which was the base of the Tactical Technological Requirements of Q-6 he was in charge of, and by Feb 1979, the general design of Q-6 was finalized, based on the requirement of the 3rd Ministry.
The original plan was to base the design of Q-6 on MiG-23BN, the ground attack version of MiG-23. However, both PLAAF and PLAN required the dogfight capability for self defense. Due to the need of dogfight capability, radar was needed, and the ground attack version had no radar. As a result, the plan was changed to base the design on MiG-23MS instead. Research performed revealed that the in order to successfully perform the required missions for PLAAF and PLAN, ground attack radar, as well as terrain-following radar
were needed, a feature MiG-23BN lacked. For dogfight, the RP-22 Sapfir-21 radar (NATO reporting name
Jay Bird) of MiG-23MS lacked the BVR capability. Decision was made to use avionics reverse engineered from F-111 to makeup these shortcomings of MiG-23, but as with other technological features adopted for Q-6, they were proven to be way too ambitious for the Chinese industrial, scientific and technological capability at the time, which resulted in prolonged development, and contributed to the final cancellation of Q-6.
Chinese consider the greatest achievement of Q-6 in its fly-by-wire
(FBW) control of the variable-sweep wing, both were the first of its kind in China. The original goal of reverse engineering the FBW of F-111 proved to be way too ambitious and had to be abandoned, and much simpler version was adopted. The triplex analog FBW of Q-6 is just slightly more advanced the most rudimentary FBW in that it used the same principle of the most rudimentary FBW in replacing the mechanical servo valves with electrical servo valves operated by electronic controller, but contrary to the most rudimentary FBW where hydraulic actuators still existed, the hydraulic actuators are replaced by electrical actuators on Q-6. The system proved to be major obstacle in the development and it took nine years to complete (1980–1988), under the personal leadership of Mr. Lu Xiaopeng. Although hailed as a technological breakthrough for the Chinese aviation by China, and provided superior performance, the Chinese system was more than 12% heavier than the simple mechanical-hydraulic controlled variable-sweep wing of MiG-23, reducing the weapon payload, fuel capacity and combat radius, which contributed partially to the final cancellation of Q-6.
was used instead. The turbofan engine was designated as WS-6 (short for Wo Shan, 涡扇), with development first begun in 1964. After seventeen years of development, the performance parameter finally reached the desired requirement in Oct 1980. Although the pre-production authorization was granted in 1981, the program continued as a research project instead of a mature one for production. In addition, research revealed that the 71 kN (122 kN with afterburner) WS-6 was not sufficient enough to power Q-6 to meet the dogfight requirement. In 1983, an improved version WS-6G (G = Gai 改 meaning improved) appeared, originally intended for the cancelled Shenyang J-13. The new engine provided thrust of 138 kN (with afterburner), with thrust to weight ratio greater than seven, but due to the limitation of the Chinese industrial capability at the time, the engine was not reliable at all, and in addition to be highly unreliable due to the immature design, the MTBO of the engine was rumored to be only around fifty hours at most, and the engine never progressed beyond the research stage under laboratory conditions. The problem in the power plant caused by the limited Chinese industrial capability was another factor contributed partially to the final cancellation of Q-6.
Jay Bird) on MiG-23MS lacked, which also lacked the BVR capability, intentionally eliminated by the former-USSR for the early export versions of MiG-23s. During the reverse engineering effort, it was discovered that the superior American designs enabled the General Electric
AN/APQ-113 attack radar to incorporate air-to-air mode with easy, even when some of the embedded software could not be fully deciphered, due to the better design theories and principles that were easier to understand. Texas Instruments
AN/APQ-110 terrain-following radar
(TFR) was reverse engineered, and placed in the nosecone of Q-6 in the same configuration as that of the AN/APQ-113 and AN/APQ-110 on F-111: the TFR was installed just below the attack radar.
However, due to the limitation of the Chinese microelectronic industry at the time, many of the solid state microelectronic circuitry could not be manufactured by China, so they had to be replaced by vacuum tubes that could be produced in China, resulting in much heavier radar system than similar American systems. Similar handicap also increased the size of other avionics, greatly increased size and weight. Other avionics included radar warning receiver, laser range finder, communication and instrument landing systems. The only purely domestic avionic was the Aim (Miao, 瞄)-6 aiming sight, which had superior performance than the PBK-3 bombing sight on MiG-23. However, the navigation and attack system Aim-6 aiming sight was part of proved to be a technological bottleneck for Chinese, caused more difficulty in the development. The reverse engineering attempt of Litton Industries
AN/AJQ-20 inertial navigation and attack system proved to be particularly difficult, and as with other avionics such as radars, it was not until a decade later in the late 1990s did China finally mastered these system completely. The limitation of the Chinese microelectronic industry at the time was yet another factor contributed to the final cancellation of Q-6. Despite the limitation, research and simulation had proved that when equipped with these avionics, Q-6 was more than three times more effective than Q-5
. However, this was not enough to save Q-6 from being cancelled.
People's Republic of China
China , officially the People's Republic of China , is the most populous country in the world, with over 1.3 billion citizens. Located in East Asia, the country covers approximately 9.6 million square kilometres...
(PRC), with the Nanchang
Nanchang
Nanchang is the capital of Jiangxi Province in southeastern China. It is located in the north-central portion of the province. As it is bounded on the west by the Jiuling Mountains, and on the east by Poyang Lake, it is famous for its scenery, rich history and cultural sites...
Aircraft Factory (later reorganized into Hongdu Aviation Industry Group) as the prime contractor. The project never went beyond the prototype stage, despite a prolonged development.
Background
The Q-6 program was initiated in the mid-1970s when during the Battle of the Paracel Islands in 1974, the People's Liberation Army Air ForcePeople's Liberation Army Air Force
The People's Liberation Army Air Force is the aviation branch of the People's Liberation Army, the military of the People's Republic of China...
(PLAAF) and People's Liberation Army Naval Air Force
People's Liberation Army Naval Air Force
The People's Liberation Army Navy Air Force is the naval aviation branch of the People's Liberation Army Navy of the People's Republic of China.-Mission:Primary Mission* Provide fleet air defense for PLAN surface combatants...
(PLANAF) proved incapable of ground support missions. Although the South Vietnamese claimed that the People's Liberation Army
People's Liberation Army
The People's Liberation Army is the unified military organization of all land, sea, strategic missile and air forces of the People's Republic of China. The PLA was established on August 1, 1927 — celebrated annually as "PLA Day" — as the military arm of the Communist Party of China...
(PLA) had bombed the South Vietnamese forces on the three disputed islands, this was in fact not true. In reality, despite the Chinese intent to do so with the deployment of 115 aircraft which flew 401 sorties in support of the battle, none of the Chinese aircraft deployed actually attacked enemy positions.
Due to the lack of modern avionics and ground infrastructure to support a modern air war, Chinese aircraft suffered navigation and other logistics problems that severely limited their performance. The first Chinese aircraft not actually reaching the islands until several hours after the battle was over. In addition to the need to upgrade its logistics capability and infrastructure, China also decided that nothing in its then aircraft inventory could fill the requirement for support missions in the South China Sea
South China Sea
The South China Sea is a marginal sea that is part of the Pacific Ocean, encompassing an area from the Singapore and Malacca Straits to the Strait of Taiwan of around...
. Fighters such as the J-5
Shenyang J-5
The Shenyang J-5 , originally designated Dongfeng-101 - , and also Type 56 before being designated J-5 in 1964, is a Chinese-built single-seat jet interceptor and fighter aircraft derived from the Soviet Mikoyan-Gurevich MiG-17. The J-5 was exported as the F-5...
, J-6
Shenyang J-6
The Shenyang J-6 was the Chinese-built version of the Soviet MiG-19 'Farmer' fighter aircraft.-Design and development:...
, J-7
Chengdu J-7
The Chengdu Jian-7 is a People's Republic of China-built version of the Soviet Mikoyan-Gurevich MiG-21. Though production ceased in 2008 it continues to serve, mostly as an interceptor, in several air forces, including China's.-Design and development:...
, and J-8
Shenyang J-8
The Shenyang J-8 is a high-speed, high-altitude Chinese-built single-seat interceptor fighter aircraft.-J-8:...
lacked a ground attack capability and were hamperes by short range. The only Chinese ground attack aircraft Nanchang Q-5
Nanchang Q-5
The Nanchang Q-5 , also known as the A-5 in its export versions, is a Chinese-built jet ground-attack aircraft based on the Soviet MiG-19. Its main role is close air support.-Design and development:...
was also short ranged and had a low payload. China's bombers such as the Harbin H-5 and Xian H-6
Xian H-6
The Xian H-6 is a license-built version of the Soviet Tupolev Tu-16 twin-engine jet bomber, built for the Chinese People's Liberation Army Air Force....
were slow and lacked a self defense capability. A new aircraft was therefore seen as desperately needed to fulfill a new naval strike mission in support of the People's Liberation Army Navy
People's Liberation Army Navy
The People's Liberation Army Navy is the naval branch of the People's Liberation Army , the military of the People's Republic of China. Until the early 1990s, the navy performed a subordinate role to the PLA Land Forces. Since then, it has undergone rapid modernisation...
(PLAN).
Immediately after the battle, both the PLAAF and PLAN submitted their requirements for a new fighter bomber/ground attack aircraft to the 3rd Ministry of PRC. After extensive research, the 3rd Ministry decided that based on the Chinese aeronautical industrial capability at the time, it was impossible to develop two separate airplanes at the same time. Instead, a decision was made to develop a single airplane with different versions tailored to meet the different needs of PLAAF and PLAN, especially when the prime requirements of the PLAAF and PLAN were similar.
In June 1976, representatives from various aircraft factories were summoned to Beijing
Beijing
Beijing , also known as Peking , is the capital of the People's Republic of China and one of the most populous cities in the world, with a population of 19,612,368 as of 2010. The city is the country's political, cultural, and educational center, and home to the headquarters for most of China's...
to discuss the project, and were instructed to come up with designs in the shortest possible time. Shenyang
Shenyang
Shenyang , or Mukden , is the capital and largest city of Liaoning Province in Northeast China. Currently holding sub-provincial administrative status, the city was once known as Shengjing or Fengtianfu...
Aircraft Factory (later reorganized into Shenyang Aircraft Corporation
Shenyang Aircraft Corporation
Shenyang Aircraft Corporation is a Chinese civilian and military aircraft manufacturer located in Shenyang. Founded in 1953, it is one of the oldest aircraft manufacturers in the People's Republic of China. Many aircraft manufacturers in China such as Chengdu Aircraft Industry Group or Guizhou...
) was the first to come up with a design, the JH-8 (FB-8), which was essentially a ground attack version of J-8II (F-8II). This was followed by the Q-6 a new design from the Nanchang
Nanchang
Nanchang is the capital of Jiangxi Province in southeastern China. It is located in the north-central portion of the province. As it is bounded on the west by the Jiuling Mountains, and on the east by Poyang Lake, it is famous for its scenery, rich history and cultural sites...
Aircraft Factory. The Xi'an
Xi'an
Xi'an is the capital of the Shaanxi province, and a sub-provincial city in the People's Republic of China. One of the oldest cities in China, with more than 3,100 years of history, the city was known as Chang'an before the Ming Dynasty...
Aircraft Factory (later reorganized into Xi'an Aircraft Industrial Corporation
Xi'an Aircraft Industrial Corporation
Xi'an Aircraft Industrial Corporation , also known as Xi'an Aircraft Company Limited is a Chinese aircraft manufacturer and developer of large and medium-sized airplanes. It is based in Yanliang District, Xi'an, Shaanxi Province. It is joint partners with 603rd Aircraft Design Institute of...
) was the last one to present a design, the Xian JH-7
Xian JH-7
The Xian JH-7 ; NATO reporting name Flounder), also known as the FBC-1 Flying Leopard, is a tandem two-seat, twin-engine fighter-bomber in service with the People's Liberation Army Naval Air Force , and the People's Liberation Army Air Force...
, also a new design. Initially, the 3rd Ministry favored the JH-8, however because the design of the J-8II was still not completed the risk was considered to be too high, it was eliminated. The projected development of JH-7 was too far out, and so the Q-6 was selected because it was believed to be the one that would be able for service the soonest.
Origin
Before Q-6 program started, China had already obtained MiG-23BN and MiG-23MS aircraft from EgyptEgypt
Egypt , officially the Arab Republic of Egypt, Arabic: , is a country mainly in North Africa, with the Sinai Peninsula forming a land bridge in Southwest Asia. Egypt is thus a transcontinental country, and a major power in Africa, the Mediterranean Basin, the Middle East and the Muslim world...
, a few downed F-111 were also provided to China by North Vietnam. Based on the research effort performed on these aircraft, it was suggested that the variable-sweep wing should be adopted for the next Chinese ground attack aircraft. The general designer of Nanchang Q-5
Nanchang Q-5
The Nanchang Q-5 , also known as the A-5 in its export versions, is a Chinese-built jet ground-attack aircraft based on the Soviet MiG-19. Its main role is close air support.-Design and development:...
, and the future academician of the Chinese Academy of Sciences
Chinese Academy of Sciences
The Chinese Academy of Sciences , formerly known as Academia Sinica, is the national academy for the natural sciences of the People's Republic of China. It is an institution of the State Council of China. It is headquartered in Beijing, with institutes all over the People's Republic of China...
(elected in 1995), Mr. Lu Xiaopeng (陆孝彭), was named as the general designer of Q-6. Lu personally visited PLAAF and PLAN numerous times to obtain their input, which was the base of the Tactical Technological Requirements of Q-6 he was in charge of, and by Feb 1979, the general design of Q-6 was finalized, based on the requirement of the 3rd Ministry.
The original plan was to base the design of Q-6 on MiG-23BN, the ground attack version of MiG-23. However, both PLAAF and PLAN required the dogfight capability for self defense. Due to the need of dogfight capability, radar was needed, and the ground attack version had no radar. As a result, the plan was changed to base the design on MiG-23MS instead. Research performed revealed that the in order to successfully perform the required missions for PLAAF and PLAN, ground attack radar, as well as terrain-following radar
Terrain-following radar
Terrain-following radar is an aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level. It is sometimes referred-to as ground hugging or terrain hugging flight...
were needed, a feature MiG-23BN lacked. For dogfight, the RP-22 Sapfir-21 radar (NATO reporting name
NATO reporting name
NATO reporting names are classified code names for military equipment of the Eastern Bloc...
Jay Bird) of MiG-23MS lacked the BVR capability. Decision was made to use avionics reverse engineered from F-111 to makeup these shortcomings of MiG-23, but as with other technological features adopted for Q-6, they were proven to be way too ambitious for the Chinese industrial, scientific and technological capability at the time, which resulted in prolonged development, and contributed to the final cancellation of Q-6.
Design
Originally the design was based on the MiG-23MS, and was initially thought to be better than the MiG-23BN, because it provided more room in the nosecone to house the radar. However the Chinese microelectronic industry could not provide the solid state electronics needed to miniaturise the intended radar, and as a result, the size of the fuselage (with the exception of length) had to be increased from the size of the MiG-23 to that of the Su-24. Research also revealed that the side-intakes of the MiG-23 design was not sufficient enough to meet the dogfight capability, so the side-intakes was changed into chin-intake instead, and Q-6 is claimed to be the first Chinese aircraft to have a chin-mounted intake.Chinese consider the greatest achievement of Q-6 in its fly-by-wire
Fly-by-wire
Fly-by-wire is a system that replaces the conventional manual flight controls of an aircraft with an electronic interface. The movements of flight controls are converted to electronic signals transmitted by wires , and flight control computers determine how to move the actuators at each control...
(FBW) control of the variable-sweep wing, both were the first of its kind in China. The original goal of reverse engineering the FBW of F-111 proved to be way too ambitious and had to be abandoned, and much simpler version was adopted. The triplex analog FBW of Q-6 is just slightly more advanced the most rudimentary FBW in that it used the same principle of the most rudimentary FBW in replacing the mechanical servo valves with electrical servo valves operated by electronic controller, but contrary to the most rudimentary FBW where hydraulic actuators still existed, the hydraulic actuators are replaced by electrical actuators on Q-6. The system proved to be major obstacle in the development and it took nine years to complete (1980–1988), under the personal leadership of Mr. Lu Xiaopeng. Although hailed as a technological breakthrough for the Chinese aviation by China, and provided superior performance, the Chinese system was more than 12% heavier than the simple mechanical-hydraulic controlled variable-sweep wing of MiG-23, reducing the weapon payload, fuel capacity and combat radius, which contributed partially to the final cancellation of Q-6.
Power plant
Research revealed that the turbojet engine was not sufficient enough to provide the thrust needed to meet dogfight requirement, so a domestic turbofan engine originally used for Chengdu J-9Chengdu J-9
|...
was used instead. The turbofan engine was designated as WS-6 (short for Wo Shan, 涡扇), with development first begun in 1964. After seventeen years of development, the performance parameter finally reached the desired requirement in Oct 1980. Although the pre-production authorization was granted in 1981, the program continued as a research project instead of a mature one for production. In addition, research revealed that the 71 kN (122 kN with afterburner) WS-6 was not sufficient enough to power Q-6 to meet the dogfight requirement. In 1983, an improved version WS-6G (G = Gai 改 meaning improved) appeared, originally intended for the cancelled Shenyang J-13. The new engine provided thrust of 138 kN (with afterburner), with thrust to weight ratio greater than seven, but due to the limitation of the Chinese industrial capability at the time, the engine was not reliable at all, and in addition to be highly unreliable due to the immature design, the MTBO of the engine was rumored to be only around fifty hours at most, and the engine never progressed beyond the research stage under laboratory conditions. The problem in the power plant caused by the limited Chinese industrial capability was another factor contributed partially to the final cancellation of Q-6.
Avionics
Avionics requirement for Q-6 was one of the most advanced one for China at its time. The original goal of reverse engineering American avionics from downed F-111 provided by North Vietnam proved to be way too ambitious to achieve given the limited Chinese industrial capability at the time, so it was decided to reverse engineer whatever China could, and use the result to upgrade Soviet avionics on MiG-23. The only way to successfully meet the ground attack mission requirements of PLAAF and PLANAF was to equip Q-6 with an airborne radar with ground attack capability, a feature lacked by the RP-22 Sapfir-21 radar (NATO reporting nameNATO reporting name
NATO reporting names are classified code names for military equipment of the Eastern Bloc...
Jay Bird) on MiG-23MS lacked, which also lacked the BVR capability, intentionally eliminated by the former-USSR for the early export versions of MiG-23s. During the reverse engineering effort, it was discovered that the superior American designs enabled the General Electric
General Electric
General Electric Company , or GE, is an American multinational conglomerate corporation incorporated in Schenectady, New York and headquartered in Fairfield, Connecticut, United States...
AN/APQ-113 attack radar to incorporate air-to-air mode with easy, even when some of the embedded software could not be fully deciphered, due to the better design theories and principles that were easier to understand. Texas Instruments
Texas Instruments
Texas Instruments Inc. , widely known as TI, is an American company based in Dallas, Texas, United States, which develops and commercializes semiconductor and computer technology...
AN/APQ-110 terrain-following radar
Terrain-following radar
Terrain-following radar is an aerospace technology that allows a very-low-flying aircraft to automatically maintain a relatively constant altitude above ground level. It is sometimes referred-to as ground hugging or terrain hugging flight...
(TFR) was reverse engineered, and placed in the nosecone of Q-6 in the same configuration as that of the AN/APQ-113 and AN/APQ-110 on F-111: the TFR was installed just below the attack radar.
However, due to the limitation of the Chinese microelectronic industry at the time, many of the solid state microelectronic circuitry could not be manufactured by China, so they had to be replaced by vacuum tubes that could be produced in China, resulting in much heavier radar system than similar American systems. Similar handicap also increased the size of other avionics, greatly increased size and weight. Other avionics included radar warning receiver, laser range finder, communication and instrument landing systems. The only purely domestic avionic was the Aim (Miao, 瞄)-6 aiming sight, which had superior performance than the PBK-3 bombing sight on MiG-23. However, the navigation and attack system Aim-6 aiming sight was part of proved to be a technological bottleneck for Chinese, caused more difficulty in the development. The reverse engineering attempt of Litton Industries
Litton Industries
Named after inventor Charles Litton, Sr., Litton Industries was a large defense contractor in the United States, bought by the Northrop Grumman Corporation in 2001.-History:...
AN/AJQ-20 inertial navigation and attack system proved to be particularly difficult, and as with other avionics such as radars, it was not until a decade later in the late 1990s did China finally mastered these system completely. The limitation of the Chinese microelectronic industry at the time was yet another factor contributed to the final cancellation of Q-6. Despite the limitation, research and simulation had proved that when equipped with these avionics, Q-6 was more than three times more effective than Q-5
Nanchang Q-5
The Nanchang Q-5 , also known as the A-5 in its export versions, is a Chinese-built jet ground-attack aircraft based on the Soviet MiG-19. Its main role is close air support.-Design and development:...
. However, this was not enough to save Q-6 from being cancelled.