IISS Strategic Comments_China's J-20.pdf
영국 국제전략연구소 (IISS, International Institute for Strategic Studies) 에서 발행하는 [Strategic Comments]
2011년 2월호에 실린 중국 Chengdu J-20 스텔스기 관련 칼럼을 소개 합니다. 위 첨부파일로 pdf 로 작성된
보고서도 함께 소개 합니다. 필요하신 분은 위 제목을 통해 내려받으면 됩니다.
IISS 의 분석 내용에 의하면, 중국이 초도비행 과정을 통해 공개된 J-20 외에 좀더 개량된 혹은 상대적으로 경량
화 시킨 5세대 스텔스 전투기를 (중국 분류로는 4세대급 전투기) 개발할 가능성이 있다고 예상하고 있습니다.
----------------------------------------------------------------------------------------------------
Saturday 05 February 2011
China's J-20: future rival for air dominance?
The world's major military powers have long known that China has been developing new combat-aircraft designs, so the emergence last December of the Chengdu J-20 did not come as a shock. It remains to be seen just what this next-generation combat aircraft's capabilities and development schedule will be, and particularly the extent to which it can challenge rival aircraft for air superiority. The project does, however, underline Beijing's aim — also reflected in its land and naval programmes — to develop armed forces that are commensurate with its status as a rising global power.
In what appeared to be a state-crafted leak, images of an aircraft carrying out runway tests at Chengdu in central China were circulated on the Internet on 21–22 December 2010. Its maiden flight took place on 11 January, only hours before United States Defense Secretary Robert Gates met with President Hu Jintao in Beijing and a week before Hu embarked on a state visit to Washington — which has repeatedly urged Beijing to be more open about its defence plans. While this timing encouraged comparisons between the American and Chinese militaries, the significance and potential impact of the J-20 will be felt as much in Tokyo, New Delhi and Moscow — as well as in Taipei. Also known in China as 'Project 718', the J-20 should be considered within this broader context, rather than as China's riposte to the US Air Force's F-22 Raptor or as an F-35 Joint Strike Fighter 'killer'.
What seemed to be official images of a gala reception marking the first J-20 flight were also swiftly published online. Guests included Li Gang, the test pilot, and Yang Wei, the director of Institute 611 at Chengdu who has been closely involved in the design of the J-20, as well as General Xu Qiliang, the head of the People's Liberation Army (PLA) Air Force.
Chinese ambitions to develop next-generation combat aircraft came to light well over a decade ago. In 1997, the US Office of Naval Intelligence identified a future fighter programme it dubbed 'XXJ' in an open-source booklet on potential threat systems. By the early 2000s there was considerable Internet 'chatter' that China's two main fighter manufacturers, Chengdu and Institute 601 at Shenyang in northeastern China, were vying for the project.
J-20's characteristics
Even the basic details of the 'prototype' — the J-20 designation has yet to be officially confirmed by China — are still unknown. What is apparent is that the aircraft is a large twin-engine design, suggesting it is intended to have a significant range and payload. The design shows some low-observable characteristics, such as the shape of its nose and forward fuselage, edge alignment and what are most likely internal weapons bays. However, its delta-wing and canard (or foreplane) layout, and specifically its canard fuselage join, is not ideal for reducing the aircraft's radar signature. Neither the US F-22 and F-35, nor Russia's Sukhoi T-50 — all 'fifth-generation' designs — have canards. European fourth-generation fighters — such as the Typhoon, Rafale and Gripen — do feature them. This common design approach was adopted in the late 1970s and early 1980s to meet a broad range of agility and performance requirements, from low-speed manoeuvrability to the supersonic flight regime. Radar-signature reduction was not a fundamental design driver for these types, as it was on later designs, such as the F-22 and T-50.
Despite the presence of canards, the J-20 does otherwise appear to be optimised for stealth in the forward sector rather than for all-aspect low-observability. This would provide an advantage over a non-stealthy platform either for beyond-visual-range air-to-air engagement or for engaging surface targets with stand-off weapons while minimising the risk of being detected and engaged by ground defences prior to weapon release. The rear aspect of the aircraft, however, looks considerably less stealthy.
The basic J-20 configuration may have been settled upon almost a decade ago. Chengdu research papers dating back to as early as 2001 have discussed the aerodynamics of a delta-canard platform, though with ventral intake rather than the J-20's lateral intake configuration. one of these papers, entitled 'Research on the Aerodynamic Characteristics of a Small Aspect Ratio, High Lift Fighter Configuration', discussed an aircraft design including canards and with 'a stress on stealth ... the nose section may adopt a shard wedge or flat-edge shaped nose cone'.
In the event the J-20 has emerged with two lateral divertless supersonic intakes (DSIs), rather than the more traditional and more mechanically complex variable-geometry inlet. In a DSI, a fixed-configuration bump is used to deal with air-flow issues rather than movable ramps or doors. The DSI approach is also used on the F-35, and has also been test flown on a variant of the Chinese J-10. A DSI may also have radar-signature benefits.
The J-20 is reminiscent of the defunct Soviet MiG 1.42 design in plan form and in the general configuration of the rear section – as well as the early plan for a similarly shaped chin intake. This is perhaps not surprising since Russia has been the main provider of military aerospace technology to Beijing since the collapse of the Soviet Union. As China's clout has grown, however, there has been growing worry in Moscow that it has been providing support to an emerging rival. This has created tension within Russian state-owned companies, including Sukhoi, over how much expertise Russia should provide. If Beijing had been given access to any research or technology related to MiG's 1.42 project, this may have been predicated on a decision by Moscow to proceed with the T-50 instead of the 1.42.
Chengdu may have received support in the design of the J-20 from its erstwhile rival for the project, Shenyang. The latter has more experience in the manufacture of large twin-engine fighter designs, such as the J-11 family based on the Russian Su-27 Flanker. Shenyang was working on a design to rival the J-20, and it is not known whether this project is continuing. The J-20 is at the heavy end of the fighter scale, leaving ample room for medium and light platforms.
Chinese military officials have indicated that a new fighter aircraft would enter into service in around 2018, and the development of the J-20 so far appears to be compatible with such a goal. However, what is not known is the state of development of the planned avionics, radar and weapons suites for the aircraft, as well as that of the engines. Significant problems in any one of these areas could push back planned in-service dates. Turbofan engine development has in the past proved to be an Achilles heel for Chinese industry, with Western and Russian engines being used in preference to nationally developed ones, such as a Russian engine on the J-10. China's capacity to produce propulsion systems is improving, but this is likely to remain a challenging area.
US technical supremacy set to continue
There was an irony in the PLA's decision to test-fly the J-20 during Gates's visit. In 2009, he had emphasised the superiority of American air power over that of China, saying: 'By 2020, the US is projected to have nearly 2,500 manned combat aircraft of all kinds. Of those, nearly 1,100 will be the most advanced fifth generation F-35s and F-22s. China, by contrast, is projected to have no fifth generation aircraft by 2020.' He added: 'By 2025, the gap only widens. The US will have approximately 1,700 of the most advanced fifth generation fighters versus a handful of comparable aircraft for the Chinese.' He was making this argument to support his decision to cap production of the F-22 Raptor at 187 aircraft — less than a third of the 648 that the US Air Force had planned to buy originally.
Gates's confidence in American air power has to be seen against the background of conflicts over the past 20 years, in which the US and its allies have enjoyed air dominance. Airspace has for the most part been uncontested except for the threat of shoulder-launched surface-to-air missiles and small-arms fire, although both wars against Iraq did see the US-led coalitions mounting large-scale offensive counter-air operations to nullify any threat. Air supremacy, however, cannot be assumed as constant.
The US F-22 requirement was first cut in 1993 to 442 following the collapse of the Soviet Union, which delayed Moscow's plan to replace the Su-27 Flanker with MiG's 1.42 design for a large fighter. The requirement was further reduced after the Russian aircraft programme was cancelled – the MiG prototype was flown only a few times, and in August 2009 was seen parked at the Zhukovsky flight test centre outside Moscow. Meanwhile, the requirement for the F-35 is in flux. The programme has been hit by further technical problems, with the B-variant of the aircraft now 'on probation' for two years. Gates warned on 6 January that should the short-take-off-and-vertical-landing variant of the F-35 not 'get ... back on track' over the course of the two years 'then ... it should be cancelled'. The in-service dates of the navy and air force variants of the F-35 also remain uncertain. Despite the cut in numbers of the F-22, and the travails of the F-35, the US Air Force looks set to continue to have technical superiority over rival nations' fighter aircraft for years to come.
Regional competition
The development of a new Chinese combat aircraft, however, must also be set against the background of regional competition.
Both India and Russia are pursuing fifth-generation combat aircraft. Sukhoi's T-50 prototype stealth fighter is intended to replace the Russian air force's Su-27 Flanker aircraft towards the end of this decade. Russia and India concluded an agreement in December under which New Delhi will 'piggyback' on the T-50 programme, in return for a substantial financial contribution, with the aircraft expected to enter into service in India around the end of the decade. India is also bolstering its air inventory in the near term, acquiring additional Su-30MKI multi-role fighters. It has also yet to decide on the winner of its medium multi-role combat-aircraft competition, for which there are — notionally at least — six bidders still in the running.
The extent to which the Chinese J-20 and Russian T-50 projects could in time challenge for air dominance is a key question. Into this calculation will come not only the timeframe in which those aircraft could enter service, but also the future role to be played in Western air forces by unmanned combat aerial vehicles. It is clear that the West's recent comparative neglect of crewed next-generation combat aircraft has not been mirrored completely by other major powers.
Copyright ©2006 - 2011 The International Institute For Strategic Studies
