The Chengdu J-20 (), also known as Weilong (, NATO reporting name: Fagin), is a twin-engine all-weather stealth fighter developed by China's Chengdu Aircraft Corporation between 2011 and 2018 for the People's Liberation Army Air Force (PLAAF). The J-20 is designed as an air superiority fighter with precision strike capability. The aircraft has three notable variants: the initial production model, the revised airframe variant with new engines and thrust-vectoring control, and the aircraft-teaming capable twin-seat variant.
Descending from the J-XX program of the 1990s, the 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 with the first J-20 combat unit formed in February 2018, making China the second country in the world to field an operational stealth aircraft.
Development
The J-20 emerged from the late-1990s J-XX program. Chengdu had previously used the double-canard configuration in the J-9, its first design and cancelled in the 1970s, and the J-10. The general configuration of Chengdu's J-XX design was first published internally in a 2001 Chengdu paper authored by Song Wencong that describes the advantages of an unstable canard and LERX configuration. In 2008, the PLAAF endorsed Chengdu Aircraft Corporation's proposal, Project 718.
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 outside the Chengdu Aircraft Design Institute (CADI). Three months later, the first J-20 prototype made its maiden flight in Chengdu. The first prototype was painted with the number "2001". In May 2012, the second prototype took flight in the CADI facility.
Several changes were made to the third J-20 prototype, numbered "2011", which made its maiden flight in March 2014. The new prototype showed increasing sophistication in design, including numerous subtle changes from the first two prototypes. The new airframe introduced modified diverterless supersonic inlet (DSI) intakes, stealth coating, streamlined underwing fairings, and redesigned vertical stabilizers. 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 the J-20 was spotted by military observers.
In October 2017, Chinese state media reported that the designs of the J-20 had been finalized, and were ready for mass production as well as being combat-ready. In March 2018, Chinese military revealed other versions of the J-20 platform were being developed.
In January 2019, Chinese media reported that a twin-seat variant of the J-20 was 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 Aircraft Corporation manufacturing facility. The aircraft is equipped with a new variant of WS-10 Taihang engines with serrated afterburner nozzles to enhance stealth. Report indicated Chengdu Aircraft Corporation terminated the manufacturing of J-20 with Russian engines in mid-2019.
Chinese media reported that a new variant of the J-20 was unveiled on July 8, 2020, and entered mass production the same day. The only change mentioned was that the new J-20 was to be equipped with thrust vectoring control. Conflicting reports emerged regarding the exact engine type. Analyst Andreas Rupprecht expressed skepticism regarding the use of Russian engines on the J-20, as 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 in 2018 China International Aviation & Aerospace Exhibition. Analyst Jamie Hunter believed the new engine type is what he called WS-10B-3, a Chinese-made thrust-vectoring engine demonstrated on the 2018 Zhuhai Airshow.
In January 2021, South China Morning Post reported that the J-20 would replace its engines with the WS-10C. The WS-10C is considered an interim solution before Shenyang WS-15 passes evaluations. Moreover, WS-10C will not be equipped with the thrust-vectoring version of the J-20 that entered mass production in 2019, which still required further testing. Overall, Chinese engineers believe WS-10C is comparable with AL-31F in performance, and the replacement would also reduce China's dependency on Russian engines. The WS-10C-powered J-20 has officially showcased to the public on 28 September 2021 at Zhuhai Airshow.
In January 2021, Aviation Industry Corporation of China released computer renderings of the twin-seat variant of the J-20 fighter in celebration of the 10th anniversary of the jet's maiden flight. In February 2021, a South China Morning Post infographic depicted a twin-seat J-20 variant powered by thrust vectoring WS-10C. In October 2021, a taxiing prototype, dubbed J-20S by analysts, was spotted near Chengdu Aircraft Corporation facilities, making J-20S the first-ever two-seat stealth fighter. The twin-seat design allows the possibility for the second operator to coordinate attacks and reconnaissance missions from other friendly aircraft via networking or unmanned combat aerial vehicles (UCAVs) linked via "loyal wingman" systems and sensors. The advantage of a second operator includes the potential for better interpreting and exploiting the enormous sensory data that could overload the limited cognitive and processing capacity for a single human, especially in a contested air combat environment.
In March 2022, Chinese state media reported that the J-20, reportedly with one engine replaced by the WS-15, had performed flight trials. In December 2022, Chinese military analysts indicated the WS-15 was undertaking the last stage of testing and development. In late December, a prototype of the new J-20 variant was observed at Chengdu Aircraft Corporation facilities. The new variant was painted in yellow primer and different from previous J-20 aircraft in airframe design, with a low-profile blended canopy, aiming to optimize transonic flight performance and maneuverability. The new prototype was speculated to be used to test the WS-15 engine and thrust-vectoring. In March 2023, the executive of Aero Engine Corporation of China (AECC) announced that serial production of the WS-15 had started. FlightGlobal speculated that small-scale production and in-flight testing of the WS-15 with the J-20 fighter was underway. On 29 June 2023, a J-20 fighter in yellow primer was observed taking off from Chengdu Aircraft Cooperation airfield fitted with reportedly two WS-15 engines. A clear photo of a WS-15-equipped J-20A fighter taking flight appeared in 2024.
In October 2023, the Pentagon reported that PLAAF was upgrading the J-20, with enhancements such as extended weapon-carrying capability, thrust vectoring nozzles, control systems for unmanned aircraft teaming, and WS-15 high-thrust engines.
In November 2024, the Aviation Industry Corporation of China (AVIC) officially announced the twin-seat variant of the J-20, designated the J-20S. Functions of the variant include long-range operations with multi-role capabilities, including air superiority, precision strikes, manned-unmanned teaming, battlefield surveillance, electronic warfare, and command and control.
Design
Characteristics The J-20 has a long and blended fuselage, with a chiseled nose section and a frameless canopy. Immediately behind the cockpit are low-observable diverterless supersonic inlet (DSI) intakes. All-moving canard surfaces with pronounced dihedral are placed behind the intakes, followed by leading edge extensions (LERX) 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 or low-observable engine exhausts.
One important design criterion for the J-20 is high stability. 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."Super Agile aircraft and method of flying it in supernormal flight." Google Patents. Retrieved 20 March 2013 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.Probert, B. "Aspects of Wing Design for Transonic and Supersonic Combat." NATO. Retrieved: 23 January 2011.Neblett, Evan et al. "Canards." AOE 4124: Configuration Aerodynamics, Department of Aerospace and Ocean Engineering, Virginia Tech, 17 March 2003. Retrieved: 28 November 2009.
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."一种小展弦比高升力飞机的气动布局研究 A High Lift Low-Aspect Ratio Aerodynamic Configuration" sina.com Retrieved 20 March 2013 Retrieved 20 March 2013"一种小展弦比高升力飞机的气动布局研究 A High Lift Low-Aspect Ratio Aerodynamic Configuration" baidu.com Retrieved 20 March 2013
The use of a bubble canopy, extensive flight-control surfaces, and canard configuration for angle-of-attack control indicates J-20's intention to operate in air-superiority missions and within-visual-range engagements. Chief test pilot Li Gang describes the J-20 as having comparable manoeuvrability to the Chengdu J-10 while being significantly better at low-observable (LO) performance. The J-20 is a multirole air superiority fighter, with the interceptor role being just one of the options.
Avionics and cockpit
The J-20's avionics aim to obtain situational awareness through advanced sensor and data fusion while denying situational awareness to the adversary through stealth and electronic warfare. The J-20 features an integrated avionic suite consisting of multi-spectral sensors capable of providing omnidirectional coverage. Official information on the type of radar that J-20s use has not yet been released publicly. Some analysts, including Janes believe that J-20s is equipped with Type 1475 (KLJ-5) 100kW active electronically scanned array (AESA) radar with 1856 transmit/receive modules, Other analysts point out that, based on the nose cross-section of the J-20 and known data about a single transmit/receive module surface in the J-16's AESA radar system, J-20s could be upgraded to accept a system with 2000–2200 transmit/receive modules.