FC-31 / J-31 (Jianjiji-31 Fighter aircraft 31)
China lacks the extensive electronic support [eg, RIVET JOINT, AWACS, etc] and aerial refueling capabilities that American stealth aicraft can rely upon. The J-31, also designated the FC-31 (Fighter China 31), might achieve an initial operational capability in the 2025 timeframe.
The Chinese military leaked the first photos of long-rumored new stealth fighter, the second model revealed in China. The J-31 attracted wide public attention in June when some online pictures showed the cutting-edge fighter fully wrapped but with its futuristic shape still discernible. The J-31 fighter, named Falcon Eagle in Chinese, took its first flight at 10:32 am Beijing local time, Wednesday 31 October 2012, along with two J-11BS fighter jets from the runway of Shenyang Aircraft Corp, the producer and researcher of the fighter in Liaoning Province.
Shenyang Aircraft Industry Group (SAC), one of the leading aircraft design and manufacturing corporations of China’s aviation industry, revealed the prototype of what might eventually become Chinese analog to the American F-35 Joint Strike Fighter. The new aircraft, said to be designated the J-31 or to have the codename F-60, has external characteristics that suggest to some that it could be used on future Chinese aircraft carriers. The J-31 prototype jet has the side number 31001, which is the origin of the J-31 nomenclature, since the first two J-20 prototypes had “2001” and “2002” side numbers, respectively.
Photos of a model labeled F-60 were posted online as early as September 2011. These images show only scaled-down models, not the real thing, with one notable difference being the single wheel in the model versus the paired nose-wheels in the real deal. This radio-controlled F-60 model had been built with the Shenyang University of Aeronautics and Astronautics [SUAA]. In June 2012 a photograph of a full scale airframe being transported on a truck trailer, obscured by netting, appeared online.
Though no characteristics of the prototype have been unveiled, one major difference is obvious: unlike its American relative, China’s J-31 has two engines, as does the previously revealed J-20. The pictures of the Chinese technology demonstrator suggest that the engines the aircraft is currently equipped with do not have thrust vectoring nozzles. Possibly the prototype is at an early a stage of testing, and might be fitted with a more sophisticated and powerful propulsion package at a later date. The twin vertical tail and wide-spaced ram air inlets are reminiscent of these features on the Lockheed Martin’s F-22 Raptor.
The J-31 inlet design features diverterless supersonic inlet [DSI] similar in concept to that used on the American F-35. The F-35's diverterless inlet lightens the overall weight of the aircraft. Traditional aircraft inlets were comprised of many moving parts and are much heavier than newer diverterless inlets. The diverterless inlet also eliminates all moving parts. DSI moved from concept to reality when it was flown on a Block 30 F-16 in a highly successful demonstration program consisting of twelve flights flown in nine days in December 1996.
Unlike the Russians and Indians, whose joint project to develop a fifth generation aircraft produced a single design, the Chinese military followed the American example and placed its bets on two horses: Chengdu Aircraft Corporation, which is already testing the J-20 fifth generation heavy combat aircraft, and Shenyang Aircraft Industry Group with its F-31/F-60 aircraft. It is unclear which America practice the Chinese have emulated. Possibly this is like the Advanced Tactical Fighter and Joint Strike Fighter programs, in which competing designs were flight tested before one was selected for production. Or possibly the J-31 and J-20 are not to be regarded as competitors, but as complementary pair such as the F-22 and F-35, because to some it appeared the aircraft may have different specializations.
The problem with the competitive fly-off explanation is that the first flight of the J-20 came in January 2010, nearly two years before the first flight of the J-31. This belies a competitive fly-off, absent a rather spectacular schedule delay in the J-31, or an extremely sedate development schedule in which such a two year discrepancy is insignficant in the long view. The complementary role explanation fails due to the apparent similarity in size. Unlike the large twin-engine air-superiority F-22 and smaller single engine air-to-ground F-35, both the graceful J-20 and the slightly shorter but visibly chunkier J-31 are twin-engined, presumably with the same
WS10 Taihang engines. If the total weight of the shorter J-31 was signficiantly less than that of the J-20 [a fact not in evidence], either the J-31 would seem rather over-powered, or the J-20 somewhat under-powered.
Carrier-based Deployment
China's J-31 stealth fighter may also be used on the carrier in future. The Liaoning would have about 40 fixed-wing aircraft on board. Possibly the complementarity lies in the J-20 being destined for land-based operations, while the J-31 is slated to go down to the sea in ships. Carrier based aircraft are normally twin-engined for safety reasons, and the Chinese might have decided that the greater structural strength needed for carrier operations would be wasted on a land-based J-20.
The shorter J-31 would also make for easier handling on an aircraft carrier, where space is at a premium. The Chinese might also have decided that little was to be gained from trying to apply a common airframe to both the land and carrier missions. The F-4 Phantom succeeded in this effort, but the American F-35 was bedeviled by the requirements of being all things to all services.
The Chinese Military Review website published computer-generated images of the J-31 fifth generation fighter jet in action, with a variety of air to air missiles. On at least two images the aircraft is depicted with an extended tailhook that sea-based aircraft use to stop after landing on the deck of an aircraft carrier. The two-wheeled front rack chassis of the J-31 prototype also suggests the aircraft was designed for naval use, facilitating the attachment of the holdback device installed on the nosegear to the catapult, like sea-based versions of Dassault’s Rafale in France, Lockheed Martin’s F/A-18 E/F Super Hornet and the Russian Su-33. There is no indications that the J-31 prototype is capable of short take off and vertical landing, a capability of the F-35B STOVL variant.
Sun Cong is chief designer of the J-15 carrier-borne fighter jet and a member of the National Committee of the Chinese People's Political Consultative Conference. Sun is also the chief designer of the J-31. He hopes the J-31 can pair up with J-20 in the future in tasks of both high and low altitudes, to maintain continuing striking capability.
In March 2013, the chief architect of the J-31 fighter Sun Cong confirmed that the improved version of the J-31 is expected to become China's next generation of carrier-based aircraft. Analysts believe that the J-31 fighter can act as a carrier-borne aircraft. One of the important factors affecting this question is the configuration of the landing gear. The front landing gear of the J-31 is designed with double wheels (the J-20, which is twice the weight, only has single front wheel), while the back landing gear adopts a dogleg structure - both these features provide strong supporting capacity and excellent shock resistance.
Considering that a carrier-borne aircraft requires the ability to withstand a greater impact when landing on an aircraft carrier than when landing on land, the J-31 seems designed to meet the requirements of a carrier-borne landing. In addition, it has been reported that if the J-31 is deployed on the aircraft carrier, it may combine in light-weight battle formations with the early-service J-15.
Engine Problems
Early reports indicate that the J-31 is equipped with twin Russian RD-93 engines - news that has been confirmed by Russia's MiG Aircraft Corporation. The Fierce Dragon light fighter developed jointly by China and Pakistan is also equipped with this model of engine. Judged against the specifications of fourth-generation aircraft, the RD-93 engine seems somewhat old,the north face hyvent, but during prototype testing the use of a stable engine with mature technology is the safest approach. Sources point out that once in service, the J-31 will hopefully carry Chinese-developed WS-13 engine, which has significantly improved performance in comparison with the RD-93.
The current weak point of the J-31 - and the J-20, and the non-stealthy J-15 [also known as the Flying Shark, which is said to be a match for US F-18 Hornet fighters] - is its Russia-made Al-31 engines, which are less powerful than those of the American F-35 fighter. However, these fighters will be more competitive in future when the Chinese jets is equipped with more powerful Chinese engines, because the American F-35 has only a single engine.
As is well known, both Chengdu’s J-20 and Shenyang’s J-31 face the problem of the lack of reliable Chinese-made jet engines with technical characteristics appropriate for a fifth generation fighter. Initially both may be fitted with Klimov RD-93 afterburning turbofans from Russia. China continues to buy Russian military jet engines. The
WS10 Taihang, China's flagship jet fighter engine, remained seriously flawed after a quarter of century of development effort. The WS10 engine was intended to equip the new J-10 fighter, low-rate initial production of which was authorised in 2002. But at least the initial run of fifty J-10 aircraft were to be fitted with Russian AL-31F engines instead. The WS10 engine was reverse-engineered from the CFM-56 commercial turbofan, which in turn was a derivative of the General Electric F101 engine originally designed for the 1960s-era Advanced Manned Strategic Aircraft, which was eventually deployed as the B-1 bomber. That is to say, after nearly a quarter century development effort on a four decade old design, China remained unable to produce a viable high performance fighter engine. It is expected that eventually both the J-20 and J-31 will be fitted with the
WS15 engine, but the core engine for the WS-15 engine was first tested in April 2005, suggesting a long road ahead.
A Russian-made RD-93 engine will power the Chinese J-31 fifth generation fighter, Rosoboronexport official told RIA Novosti 10 NOvembe 2014. "J-31 with the Russian engine RD-93 is considered to be an export program, able to compete with the American F-35 fifth generation aircraft on the regional markets," Rosoboronexport’s Air Force Equipment Export Department Head Sergey Kornev said. "The program is ambitious, but very real, especially considering the high cost of F-35 and some problems with its development," Kornev added. Russian RD-93 engines are a variant of the RD-33 engines, initially developed to power MiG-29 fighters. The RD-93 was developed by Russia’s Klimov design bureau specifically for the FC-1 fighter, known in Pakistan as the JF-17 Thunder.
Export Potential
Since August 2013 China's fourth-generation stealth fighter, the J-31 Falcon Hawk, carried out more than three sets of trial flights at a rapidly increasing frequency. America's fourth-generation [according to Chinese taxonomy] equivalent has achieved huge market penetration, and Chinese analysts believe that the performance of the J-31 will make it a strong competitor in this market.
Although similar to the J-20 stealth fighter, the J-31's overall aerodynamic design and stealth appearance is not identical with J-20, which has a higher degree of public exposure. Military analysts prefer to compare the relation of J-31 and J-20 with that of the US Air Force F-22 and F-35. The J-31 and F-35 use the same DSI inlet (non-boundary layer separated lane supersonic inlet) design, the difference is, the F-35 uses a single engine to provide power, but J-31 is designed with double engines. In addition, some models of F-35 support the short distance/vertical landing; J-31 cannot do this for the time being.
China's Air Force test pilot expert Xu Yongling claims that the J-31's stealth aerodynamic design, stealth engine design and stealth coating design have all reached internationally advanced standards in stealth technology. He also claims that the J-31 possesses both stealth and a considerable payload capability. In addition, Xu Yongling says that China has its own considerations in the development of fourth-generation aircraft, taking account not only of the need for stealth, but also of its performance in air-to-ground and air-to-air combat, and the relevant weapons requirements. This means that in payload, the J-31 will prevail over the F-35.
A landmark in international military aviation history, the Chinese fourth-generation stealth aircraft will not only have a great impact on combat strategy, but also exercise a tremendous influence on geopolitics, especially on international relations and the geo-strategic situation in the Asia-Pacific region. The stealth fighter has gone beyond a simple weapons platform; its presence is now an indication of the balances and the strategic considerations at play among different countries.
It could be said that the high-tech weapon systems represented by stealth fighters are becoming a new variable in the Sino-US strategic game. Chinese experts predict that the J-31 will make rapid inroads in the international market in the future and will steal the limelight from the F-35. China's fourth-generation aircraft will become a new option for those countries which have not yet made the decision to purchase the F-35. In particular for those countries which are excluded from access to US arms exports, China's fourth generation aircraft may be attractive. The J-31, with its main target as the export market, represents a potential threat to US arms manufacturers.
The Pakistan Air Force (PAF) showed interest in buying fourth generation stealth fighter aircraft FC-31 from China. Janes reported 12 November 2014 that the Pakistan Air Force (PAF) was in talks with China to buy 30 to 40 of the Shenyang FC-31 twin-engined stealth fighter displayed at Airshow China 2014 in Zhuhai. Pakistani Defence Production minister Rana Tanveer Hussain said in late Novembe 2014 that the matter was being discussed with Chinese authorities. According to Dawn, it was for the first time that a senior government functionary had confirmed talks with China over purchase of the longer-range stealth aircraft.
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