The Sino-Indian face-off in Ladakh continues towards the harsh forthcoming winter. As the excitement of Rafale induction into Indian Air Force (IAF) settles, it is time to have a fresh look at China’s J-20 which has started becoming operational in sizeable numbers. Is it overhyped or a reality that India must try and fully understand and factor into its operational plans? In any case the whole world, including the Americans see this weapons platform as a potent threat and are working towards counter-measures. India must also look at the changed threat perception that this stealthy fifth generation aircraft creates if it were to one day be fielded with its long range missiles. This article looks at the status of the entire program and its implications for India.
The Chengdu J-20 “Mighty Dragon” (NATO Name: Black Eagle) is a single-seat, twinjet, all-weather, stealth, fifth-generation fighter aircraft developed by China’s Chengdu Aerospace Corporation for the People’s Liberation Army Air Force (PLAAF). The J-20 is designed as an air superiority fighter with precision strike capability, and evolved from the Chinese J-XX program of the 1990s. Aircraft made its maiden flight on 11 January 2011, and was officially revealed at the 2016 China International Aviation & Aerospace Exhibition. The aircraft entered service in March 2017, and reportedly began its combat training phase in September 2017. The first J-20 combat unit was formed in February 2018. The J-20 is the world’s fourth fifth-generation stealth fighter aircraft after the American F-22, F-35, and Russian Su-57. The J-20 will effectively supersede Su-27sk, Su-30MKK and Su-30MK2 aircraft in PLAAF inventory.
The Chinese J-XX development program was started in the late 1990s. A proposal from Chengdu Aerospace Corporation, designated Project 718, won the PLAAF endorsement following a 2008 competition against a Shenyang proposal that was much larger than the J-20. In 2009, a senior PLAAF official revealed that the first flight was expected in 2010–11, with a service entry date by 2019. On 22 December 2010, the first J-20 prototype underwent high speed taxiing tests and three months later, the first J-20 prototype made its maiden flight in Chengdu.
Several changes were made to J-20 prototypes, including new low-observable intake and stealth coating, as well as redesigned vertical stabilizers in 2014. Analysts noted new equipment and devices for multi-role operations such as integrated targeting pods for precision-guided munition, and six additional passive infrared sensors can also be spotted around the aircraft. In December 2015, the low rate initial production (LRIP) version of J-20 had been spotted by a military observer. Chinese state media reported in October 2017 that the designs of J-20 had been finalized, and is ready for mass production as well as combat-ready.
In January 2019, Chinese media reported that a twin-seat variant of the J-20 is rumored to be in development for use in tactical bombing, electronic warfare and carrier strike roles. In November 2019, a J-20 painted in yellow primer coating was spotted during its flight testing by defense observers at the Chengdu Aerospace Corporation manufacturing facility. The aircraft will be equipped with new variant of WS-10 Taihang engines with serrated afterburner nozzles to enhance stealth.
Chinese state backed media reported that a new variant of the J-20, the J-20B, was unveiled on July 8, 2020 and entered mass production the same day. The only change mentioned was that the J-20B was to be equipped with thrust vectoring control. Andreas Rupprecht expressed skepticism regarding the use of thrust vectoring. He believes that the J-20 is using a variant of the WS-10 which he called the WS-10C. This engine has improved thrust, stealthier serrated afterburner nozzles and higher reliability, but it is not designed for thrust vectoring unlike the WS-10 TVC demonstrated on a J-10 at the 2018 China International Aviation & Aerospace Exhibition.
The J-20 has a long and wide fuselage, with a chiseled nose section and a frameless canopy. Immediately behind the cockpit are low observable intakes. All-moving canard surfaces with pronounced dihedral are placed behind the intakes, followed by leading edge extensions merging into the delta wing with forward-swept trailing edges. The aft section has twin outward canted all-moving fins, short but deep ventral strakes, and conventional round engine exhausts.
One important design criterion for the J-20 is high instability. This requires sustained pitch authority at a high angle of attack, in which a conventional tail-plane would lose effectiveness due to stalling. On the other hand, a canard can deflect opposite to the angle of attack, avoiding stall and thereby maintaining control. A canard design is also known to provide good supersonic performance, excellent supersonic and transonic turn performance, and improved short-field landing performance compared to the conventional delta wing design.
Leading edge extensions and body lift are incorporated to enhance performance in a canard layout. This combination is said by the designer to generate 1.2 times the lift of an ordinary canard delta, and 1.8 times more lift than an equivalent sized pure delta configuration. The designer claims such a combination allows the use of a smaller wing, reducing supersonic drag without compromising transonic lift-to-drag characteristics that are crucial to the aircraft’s turn performance.
Official information on the type of radar that J-20s use have not yet been released publicly. Some analysts believed that J-20s used Type 1475 (KLJ-5) active electronically scanned array (AESA) radar with 1856 transmit/receive modules, but more recent information’s revealed that this radar was designed for upgraded versions of J-11D. Other analysts point out that, based on nose cross-section of J-20 and known data about a single transmit/receive module surface in the J-16’s AESA radar-system, J-20s likely fit 2000–2200 transmit/receive modules.
Targeting and Communication
An electro-optical/infra-red targeting system and an advanced communications suite on top of the aircraft enables it to datalink with other friendly platforms, such as airborne early warning drones. Six electro-optic sensors called Distributed Aperture System similar to AN/AAQ-37 Electro-optical Distributed Aperture System EODAS can provide 360-degree coverage for pilot with sensor fusion combining radar signal with IR image in order to provide better situational awareness. The combination of an integrated targeting pod with spherically located passive-optical tracking system is reported similar to the design concept of Lockheed Martin F-35’s avionic suite. Beijing A Star Science and Technology has developed the EOTS-86 electro-optical targeting system and Electro-Optical Distributed Aperture System for the J-20 and potentially other PLAAF fighters to detect and intercept stealth aircraft.
Cockpit and Displays
The aircraft features a glass cockpit, with one primary large color liquid crystal displays (LCD) touch-screen, three smaller auxiliary displays, and a wide-angle holographic head-up display (HUD). The size of the primary LCD screen is 24 x 9 inches (25.63 by the diagonal) with two systems for redundant illumination.
The main weapon bay is capable of housing both short and long-range air-to-air missiles (AAM) (PL-9, PL-12C/D &PL-15 – PL-21) while the two smaller lateral weapon bays behind the air inlets are intended for short-range AAMs (PL-10). These side bays allow closure of the bay doors prior to firing the missile, thus allowing the missile to be fired in the shortest time possible as well as enhancing stealth. The J-20 is reported to lack an internal autocannon or rotary cannon, suggesting the aircraft is not intended to be used in short range dogfight engagements with other aircraft but engage them with from long standoff ranges with missiles such as the PL-15 and PL-21.
While the fighter typically carries weapons internally, the wings include four hard-points to extend ferrying range by carrying auxiliary fuel tanks. However, much like the F-22, the J-20 is unlikely to carry fuel tanks on combat missions due to its vulnerability in such a configuration, thus this configuration remains valuable for peacetime operations, such as transiting between airbases. The fighter is able to carry four medium/long range AAMs in main bay and short-range missile one in each lateral weapon bay of the aircraft. A staggered arrangement with six PL-15s is possible depending on the rail launcher for missile mounted in the future.
The Low rate initial production models of the Chengdu J-20 were equipped with Shenyang WS-10B – a variant of the engine developed on the Chengdu J-10. Some other sources suggest that the initial production J-20s are equipped with the Salyut AL-31FM2, a highly upgraded variant of the Lyulka AL-31, the engine has maximum afterburning thrust of 145 kN (32,600 lbf). Test airframes have also been seen equipped with WS-10 variants. In the long term, the aircraft is planned to be equipped with the WS-15 engine which produces 180 kN of thrust, currently under development, The new Xian WS-15 engine would enable substantial super-cruise speeds. According to Global Security, the engine core, composed of high pressure compressors, the combustion chamber, and high pressure turbines were successfully tested in 2005. An image of the core appeared in the 2006 Zhuhai Air Show. Without the WS-15 engine the J-20 is not capable of super-cruise. The J-20B version with thrust vectoring nozzles reportedly still uses Saturn AL-31F M2 turbofans. The aircraft is equipped with a retractable refueling probe embedded on the right side of the cockpit, to help the fighter to maintain stealth while flying greater distances.
Level of Stealth
The J-20’s nose and canopy appear to use a similar stealth shaping design as the F-22, and perhaps yielding similar signature performance from the front. However the aircraft’s side and axi-symmetric engine nozzles may expose the aircraft to radar. One prototype has been powered by WS-10G engines equipped with different jagged-edge nozzles and tiles for greater stealth.
Use of canards on a low-observable design, should guarantee radar detection and a compromise of stealth. However, Northrop Grumman’s proposal for the U.S. Navy’s Advanced Tactical Fighter (ATF) incorporated canards on a stealthy airframe. Lockheed Martin employed canards on a stealth airframe for the Joint Advanced Strike Technology (JAST) program during early development before dropping them due to complications with aircraft carrier recovery. McDonnell Douglas and NASA’s X-36 featured canards and was considered to be extremely stealthy. Radar cross-section can be further reduced by controlling canard deflection through flight control software, as is done on the Eurofighter.
The diverterless supersonic inlet (DSI) enables an aircraft to reach Mach 2.0 with a simpler intake than traditionally required, and improves stealth performance by eliminating radar reflections between the diverter and the aircraft’s skin. J-20’s DSI reduces the need for application of radar absorbent materials.
In May 2018, Indian Air Chief Marshal B.S. Dhanoa claimed that Su-30MKI fighters could detect J-20 from “several kilometers away” amid reports from the Indian media that the J-20 is undetectable. Analyst Justin Bronk from Royal United Services Institute noted that Chinese are possibly flying the J-20 with radar reflectors during peacetime for safety and training purposes due to the potential for accidents and identification from other aircraft or ground installations.
Prototype Models and Flight Testing Status
On 11 January 2011, the J-20 made its first flight, lasting about 15 minutes, with a Chengdu J-10B serving as the chase aircraft. After the successful flight, a ceremony was held, attended by the pilot, Li Gang, Chief Designer Yang Wei and General Li Andong, Deputy-Director of General Armaments. On 17 April 2011, a second test flight of an hour and 20 minutes took place. On 5 May 2011, a 55-minute test flight was held that included retraction of the landing gear.
On 26 February 2012, a J-20 performed various low-altitude maneuvers. On 10 May 2012, a second prototype underwent high speed taxiing tests, and flight testing that began later that month. On 20 October 2012, photographs of a new prototype emerged, featuring a different radome, which was speculated to house an AESA radar. In March 2013, images of the side weapon bays appeared, including a missile launch rail.
On 16 January 2014, a J-20 prototype was revealed, showing a new intake and stealth coating, as well as redesigned vertical stabilizers, and an Electro-Optical Targeting System. This particular aircraft, numbered ‘2011’, performed its maiden flight on 1 March 2014 and is said to represent the initial pre-serial standard. By the end of 2014, three more pre-serial prototypes were flown: number ‘2012’ on 26 July 2014, number ‘2013’ on 29 November 2014 and finally number ‘2015’ on 19 December 2014.
On 13 September 2015, a new prototype, marked ‘2016’, began testing. It had noticeable improvements, such as apparently changed DSI bumps on the intakes, which save weight, complexity and radar signature. The DSI changes suggested the possibility of more powerful engines being used than on its predecessors, likely to be an advanced 14-ton thrust derivative of the Russian AL-31 or Chinese Shenyang WS-10 turbofan engines, though, by 2020 the J-20 is planned to use the 18–19 ton WS-15 engine, enabling the jet to super-cruise without using afterburners. The trapezoidal flight booms around the engines were enlarged, possibly to accommodate rearwards facing radars or electronic jamming equipment. The fuselage extends almost entirely up to the engine’s exhaust nozzles. Compared to its “2014” and “2015” predecessors, the J-20’s fuselage contains more of engine’s surface area inside the stealthy fuselage, providing greater rear-facing stealth against enemy radar.
In November 2015, a new J-20 prototype, numbered ‘2017’, took to the sky. The most significant change in the new prototype is the reshaped cockpit canopy, which provides the pilot with greater visibility. The lack of other design changes suggest that “2017” is very close to the final J-20 production configuration. Since ‘2017’ is likely the last J-20 prototype, low rate initial production of the J-20 is likely to have begun in 2016. It has been reported that the design of J-20 is already mature and will not directly use the 117S engine. There were still a series of technical problems that needed to be tackled, including the reliability of its WS-15 engines, the aircraft’s flight control system, stealth coatings and hull materials, and infrared sensor.
In late December 2015, a new J-20 numbered 2101 was spotted; it is believed to be the LRIP version of the aircraft. In October 2017, Chinese media reported that Chengdu Aerospace Corporation (CAC) initiated a series production for the J-20 and is on a path towards achieving full operational capability with the People’s Liberation Army Air Force (PLAAF). Initially, the lack of a suitable indigenously produced engine hindered the mass production of the J-20, however in September 2018, it was reported that issues with the development of the WS-15 engine, particularly the reliability of the turbine blades overheating at top speeds are fixed and after further minor refinements it should be ready for full installation. The actual facts need to be ascertained.
At least six J-20s are in active service, with tail numbers 78271-78276 identified. Another six were believed ready to be delivered. On 9 March 2017, Chinese officials confirmed that the J-20 had entered service in the Chinese air force. It is anticipated that before 2020 China be equipped with the Chengdu J-20 low observable combat aircraft. The International Institute for Strategic Studies (IISS) has averred that the USA could lose its lead on operational stealth aircraft.
The J-20 officially entered service in September 2017 making China the second country in the world—after the United States—and the first in Asia to field an operational fifth-generation stealth aircraft.
The PLAAF began inducting J-20s into combat units in February 2018. The aircraft entered service with the 9th Air Brigade based at Wuhu Air Base, Anhui province in late 2018 – March 2019, replacing Su-30MKK fighters previously deployed there. People’s Liberation Army Air Force has reportedly received 50 by early 2020. There are others who feel such a high rate of production is over-hyped by Chinese state-controlled media.
On 27 August 2019, the Central Military Commission of the People’s Liberation Army have approved the J-20 as the PLAN’s future primary fighter, beating out the FC-31. Arguments for the J-20 state that the plane is far more advanced, longer ranged and carries a heavier payload than the FC-31, while those supporting the FC-31 argued that it is cheaper, lighter and far more maneuverable than the J-20. It is likely that the J-20 would be commissioned upon the Type 002 aircraft carrier under construction, however, the length of the J-20 means that it has to be shortened to be considered operable on an aircraft carrier.
Pilot Training and Initial Exercises
Pilot training for the J-20 started as early as March 2017, after the fighter entered limited service in the initial operational capability (IOC) phase. During the IOC phase, the fighters equipped with radar reflectors, also known as Luneburg lens to enlarge and conceal the actual radar cross section.
The J-20 participated in its first combat exercise in January 2018, practicing beyond-visual-range maneuvers against China’s fourth-generation fighters such as J-16 and J-10C. Training with mixed generations allow pilots to become familiar with fifth-generation aircraft, and to develop tactics both for and against them. Chinese Ministry of National Defense also revealed that J-20 has conducted night confrontation missions during several coordinated tactical training exercises. The J-20 participated in its first over-ocean combat exercise in May 2018.
A 2015 RAND Corporation report, felt that J-20’s combination of forward stealth and long range puts America’s surface assets at risk, and that a long-range maritime strike capability may cause the United States more concern than a short range air-superiority fighter like the F-22. In its 2011 Annual Report to Congress, the Pentagon described the J-20 as “a platform capable of long range, penetrating strikes into complex air defense environments.” Observers were not able to reach a consensus on J-20’s primary role. The J-20 clearly seems to be an air-to-air fighter with an emphasis on forward stealth, high-speed aerodynamics, range, and adequate agility. The J-20 with its long range missile armament could threaten vulnerable tankers and ISR/C2 platforms such as the Boeing KC-135 Stratotanker and Boeing E-3 Sentry AWACS, depriving Washington of radar coverage and strike range. However one of these targets, the Northrop Grumman E-2D Advanced Hawkeye, is reported to be optimized for spotting fighter sized stealth aircraft such as the J-20. After the deployment announcement, several analysts noted that experience that the PLAAF will gain with the J-20 will give China a significant edge over India, Japan, and South Korea, which have struggled to design and produce their own fifth-generation fighters on schedule. However, despite the failure of their indigenous projects, Japan and South Korea operate the imported F-35A, negating this potential technological disparity. United States Marine Corps created a full-scale replica (FSR) of a Chengdu J-20 in December 2018. The replica was spotted parked outside the Air Dominance Center at Savannah Hilton Head Airport in Georgia. The United States Marine Corps later confirmed that the aircraft was built for training.
F-35 Design Compromise Helped J-20 Design
In April 2009, a Wall Street Journal report indicated that, according to the Pentagon, information from the Lockheed Martin F-35 Lightning II had been compromised by unknown attackers that appeared to originate from China. There is some speculation that the compromise of the F-35 program may have helped in the development of the J-20.
Aircraft Specifications and Armament
|Specification||J 20||F 35||F 22||Sukhoi Su-57||Rafale|
|Length||20.4 m||15.7 m||18.92m||20.1 m||15.27 m|
|Wing Span||13.5 m||11 m||13.56 m||14.1 m||10.90 m|
|Gross Weight||32,092 kg||22,471 kg||29,410 kg||25,000 kg||15,000 kg|
|Internal Fuel||11,340 kg||8,278 kg||8,200 kg||10,300 kg||4,700 kg|
|Combat Range||2,000 km||1,410 km||1,093 km||1,500 km||1,850 km|
|Missile Carriage Internal||4+2||4||8||6||Nil (14 External Hardpoints)|
|Long Range Missile||PL-15 200 km+||MBDA Meteor 180+ km||MBDA Meteor 180+ km||R-37 150 km+||MBDA Meteor 180+ km|
What is a Fighter Generation Fighter
The fifth generation was ushered in by the Lockheed Martin/Boeing F-22 Raptor in late 2005. These aircraft are designed from the start to operate in a network-centric combat environment, and to feature extremely low, all-aspect, multi-spectral signatures employing advanced materials and shaping techniques. They have multifunction AESA radars with high-bandwidth low-probability of intercept. IRST and other sensors are fused in for Situational Awareness and to constantly track all targets of interest around the aircraft’s 360 degree bubble. Avionics suites rely on extensive use of very high-speed integrated circuit (VHSIC) technology and high-speed data buses. Integration of all these elements is claimed to provide fifth-generation fighters with a “first-look, first-shot, first-kill capability”. In addition to its high resistance to ECM, they can function as a “mini-AWACS”. Integrated electronic warfare system, integrated communications, navigation, and identification (CNI), centralized ‘vehicle health monitoring’, fibre-optic data-transmission, and stealth are important features. Maneuver performance is enhanced by thrust-vectoring, which also helps reduce takeoff and landing distances. Super-cruise is inbuilt. Layout and internal structures minimize RCS over a broad bandwidth of frequencies. To maintain low signature primary weapons are carried in internal weapon bays. Stealth technology has now advanced to where it can be employed without a trade-off with aerodynamics performance. Signature-reduction techniques include special shaping approaches, thermoplastic materials, extensive structural use of advanced composites, conformal sensors, heat-resistant coatings, low-observable wire meshes to cover intake and cooling vents, heat ablating tiles on the exhaust troughs and coating internal and external metal areas with radar-absorbent materials and paints. These aircraft are very expensive.
J-20 is larger than Sukhoi T-50 and Lockheed Martin F-22 Raptor. It seems to have borrowed the design concepts from the American and Russian fifth Generation programs.
4.5 Generation Fighters
Military budget cuts after Cold war, and high funding requirements of the fifth generation fighter, resulted in a term called the 4.5th generation fighters in late 1990s. This sub-generation saw advanced digital avionics, newer aerospace materials, modest signature reduction, and highly integrated systems and weapons. These fighters operated in network-centric environment. Key technologies introduced included BVR AAMs; GPS-guided weapons, solid-state phased-array radars, helmet-mounted sights (HMDS), and improved secure, jamming-resistant data-links. A degree of super-cruise ability (supersonic without afterburner) was introduced. Stealth characteristics focused on front-aspect radar cross section (RCS) reduction through limited shaping techniques. Eurofighter Typhoon, Dassault Rafale, Saab JAS 39 Gripen, and Russian Su-35 were in this category. Many of them are still being produced and evolving. It is quite possible that they may continue in production alongside fifth-generation fighters due to the expense of developing the advanced levels of technology. 4.5th generation fighter aircraft are now expected to have AESA radar, high capacity data-link, enhanced avionics, and ability to deploy advanced armaments.
Comparison with Rafale
Comparisons are being drawn with the IAF’s newly inducted Rafale. Rafale is a 4.5 generation aircraft. It has partial stealth features, but has no internal weapons bays. Also the aircraft first flew in 1986, as such the aircraft basic design features are relatively old. Aircraft is much smaller than the J-20, literally half the weight and volume. The so called ‘expert’ in Chinese Communist Party’s tabloid Global Times, down play Rafale capabilities and compare it as just better than the Su-30 MKI and a generation below Chinese PLA’s J-20 fighter. But many are questioning the J-20 stealth capability in view of the crudely shaped, radar signals reflecting canard controls. J-20’s limited stealth features, when compared with the US aircraft, and its use of an older Russian engine have also been questioned. Some are also questioning the inability of J-20 to currently be able to super-cruise, which Rafale can already do. Only time will tell if J-20 is a real fifth generation aircraft or has just been touted as one. Experts are also questioning the electronic warfare suite of J-20, which in case of Rafale is a comprehensive package covering the entire spectrum of threats. The J-20 uses the same engine as Su30. J-20 has achieved some Low Observable design goals for enhanced stealth. However, some aspects of the aircraft, such as the round nozzle of earlier models may work against its stealth capabilities. But the Rafale engine is better in terms of reliability, longevity and maintainability. There are also serious issues of J-20 engine maintenance and reliability. The planned Chinese engine WS-15 is still well behind schedule. It is unknown when the WS-15 will be actually ready. The Rafale Snecma M 88 engines are time tested.
J-20 is still inducting, while Rafale has been combat proven for 20 years in Iraq, Afghanistan, Mali, Libya and Syria. Rafale is an omni-role aircraft. It can carry out at least four missions in one sortie while the J-20 cannot carry out multiple missions is one go.
China’s criteria for defining aircraft generations differs from accepted international standards. China defines aircraft generations based upon when an aircraft was integrated into the air force. Per China’s criteria, the J-20 is considered a fourth-generation aircraft. They also underplay Western aircraft and call the Rafale a 3rd Generation aircraft. as per their own classifications J-20 and f-16 are both 4th Generation aircraft. They thus do not have a real equivalent of the F-22 or f-35. China’s PL-15 is claimed to have much higher range than most Western missiles, but these are all one sided Chinese figures, and missile has yet to be operationally deployed. The American AIM-260 with advanced capabilities and dual mode seeker is meant to be better than the PL-15. Americans have also become conscious of the risk of China stealing Western designs and have begun to guard the new weapon technologies.
Summarise – Implications for India
In the early 1990s, after seeing the American employment of air power in Iraq, Chinese leadership realised the importance an began concentrating on the air and space technologies and platforms. While initially they reverse engineered Russian and American designs and also stole some through espionage including cyber attacks, they subsequently invested large sums in the R&D. The PLAAF today views stealth technology as a core capability in its transformation from a predominantly territorial air force to one capable of conducting both offensive and defensive operations.
The J-20 is meant for network-centric operations that will enable these cutting-edge fighters to access real-time information from satellites and unmanned air vehicles (UAVs). The J-20’s “combination of forward stealth and long range air-to-air missiles should also be of concern to India’s high value airborne assets such as AWACS and Flight refuelers. Figures of J-20’s range, vary between 1,200 and 2,700 kilometers, but it is likely to be significant considering the internal fuel. With aerial refueling, it will be even much more.
A lot of what Chinese project in terms of capability is highly overstated to put others on the defensive and also a means to sell weapon platforms across the world. Nevertheless, it is best to assume the worst case scenario and India must build its own matching technology platforms. The J-20 has the potential to considerably enhance China’s regional military strength. Once J-20 actually becomes a fully operational stealth fighter, it should be of concern to India and other neighbours in the South East Asia. The J-20 will enhance China’s military leverage against opposing forces in the region. Like India was nearly 20 years behind the Chinese in economic reforms, India is nearly that much behind in indigenous defence technologies. For India it is time to put the heads and skills together and drive Make-in-India defence beyond just slogans. India needs to push the AMCA and LCA development and Production. Also India must quickly get the iAF squadrons to get back to 42 from current all time low of 29.
Picture Credit: asiatimes.com