J-20: The Stealth Fighter That Changed PLA Watching Forever

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J-20: The Stealth Fighter That Changed PLA Watching Forever

A decade after the J-20’s maiden flight, a look back at China’s fifth generation stealth fighter – and how it changed PLA watching forever.

J-20: The Stealth Fighter That Changed PLA Watching Forever
Credit: Sina Weibo

The weeks leading up to January 11, 2011, marked a watershed episode for PLA watching. After years of cross-referencing enthusiast Chinese language defense chatter, monitoring the People’s Liberation Army’s operational security (OPSEC), carefully tracking rare semi-official and official statements, and debates about realism and ambition, the elusive fifth generation fighter project known since the mid-2000s variously as J-XX, J-13, J-14, XXJ, finally emerged in blurry poor-quality pictures at Chengdu Aircraft Corporation’s (CAC) factory from late December 2010. It arrived right on schedule.

As clearer pictures percolated from Chinese-language defense boards to the English language PLA watching forums, and then onto aerospace and defense blogs and mainstream alphabet soup media outlets, the finalized designation – J-20 – became accepted and widely used. Finally, on the aforementioned date, the first J-20 technology demonstrator conducted a successful maiden flight, accompanied by a J-10AS twin-seater chase plane.

In the years since then, including recently, much has been said and debated over the exact military and strategic consequences of the emergence of J-20 and the kind of fighter it will be. Less spoken of is the vindication and emergence of the modern PLA watching grapevine and methodology, whose open-source collaboration and dissemination of information was at the time able to predict various key aspects of the aircraft’s characteristics, milestones, and parameters, months or in many cases years before they were conveyed by traditional defense media or open-source government and military publications.

Big ticket PLA projects prior to the J-20 – such as the J-10 fourth generation fighter, 054/A frigates, 052B/C destroyers, and KJ-2000 AEW&C – all enjoyed their own lengthy period of speculation and analysis prior to their unveiling, but the limited number of stealth fighter types in the mid-2000s up to J-20’s maiden flight put the methodology of PLA watching to the test, which it ultimately passed with flying colors. It is not an exaggeration to say that since the J-20, the predictions and anticipation for various big ticket PLA projects that have emerged – the 052D and 055 destroyers, Y-20 strategic transport, FC-31 5th generation demonstrator, 002 and 003 aircraft carriers, 075 amphibious assault ship, among many others – as well as, various projects to emerge in the near future – the FC-31 derived carrier-borne fifth generation fighter, H-20 stealth bomber, and next generation surface combatants – would not have been taken seriously had the years of lead up to J-20 not so accurately predicted aspects of the aircraft, from configuration to role to expected arrival period.

It is in this context that the first decade of the J-20’s development, entry into service, and maturation will be discussed and reflected upon, and the prospects for its second decade be considered.

The highest quality picture of the first J-20 technology demonstrator airframe, s/n 2001, on its maiden flight. Image from Chinese social media.

Reactions and Controversies

It is interesting to examine, in retrospect, how much of the initial English-language media reaction to J-20’s emergence remains unchanged today.

Initial, incorrect estimates of the J-20’s length have proven to be the biggest mistake (pun perhaps slightly intended), placing it at a gargantuan 22-23 meters long. In subsequent years, many comparative analyses of the aircraft revised its length down to about 20.8 meters (still a large fighter providing significant internal volume), but far from the 23-meter estimates initially circulated. Alas, the effect lingers, for in successive years and even to now, the most popular descriptions of the aircraft’s role portray it as a dedicated interceptor or a dedicated striker, both no doubt initially informed by incorrect overestimates of the aircraft’s size (and by extension, overestimates of its range as well as weapons bay dimensions).

Notwithstanding the consistent earliest Chinese-language defense rumors and subsequent official AVIC confirmation of the J-20’s role, it appears that in the foreseeable future J-20 will largely be seen by the media as an interceptor or a strike aircraft rather than an air superiority fighter (perhaps until the PLA Air Force feels comfortable enough to allow the aircraft to demonstrate more of its flight envelope or until the aircraft receives engines with thrust vectoring and conducts a Pugachev’s Cobra at the Zhuhai Air Show). Nevertheless, as every year passes, it is difficult to assess if foreign commentary on the J-20’s role reflects a genuine consideration of evidence or arises from some underlying discomfort or disbelief that a PLA stealth fighter may be intended to compete in a generally symmetric way with the F-22 and F-35, the former of which in particular has attained something of a mythic status in defense watching circles.

The other great controversy over the J-20’s performance is in respect to its stealth. Some reasonable commentary surrounding the J-20’s engine nozzles (non-serrated in the original Al-31 powered aircraft, but now serrated in the WS-10 powered current production airframes) and their adverse effect on rear aspect stealth unfortunately are often tarnished by categorical pronouncements of the aircraft’s canard delta configuration as inherently incompatible with a VLO (very low observable) airframe.

While it is reasonable to consider the weighted benefits and costs of design decisions in any aircraft, the idea that the canards are inherently non-stealthy flies in the face of past canard stealth aircraft concepts studied even by established U.S. aerospace giants such as Lockheed Martin (in one of its original CALF configurations, a canard delta that preceded the Joint Strike Fighter’s F-35) and Northrop Grumman (in one of its YF-23-derived NATF configurations). If the physics of canards were as incompatible as perhaps popularly postulated, such configurations would never have been entertained to begin with. This of course doesn’t even consider some of CAC’s own recently revealed publications, one of which specifically addresses the radar-cross section impact of a canard aircraft configuration compared to a conventional tailplane configuration.

The lineage and design of the J-20 is another great beneficiary for defense media clicks. Over the years, the design of the J-20 has been variously accused of being derived, copied, or reverse engineered from (in no particular order) the F-22, F-35, F-117, Mig 1.44, Mig-31, and even Rafale and Eurofighter Typhoon. Some of this appears to arise from the J-20’s unique canard delta configuration, while other commentaries note how similar various aspects of the J-20’s stealth shaping are to U.S. designs such as the F-22 and F-35.

The fact that the J-20 is not CAC’s first soiree with the canard delta configuration seems to escape many. The preceding J-10 itself is the most obvious example of this, with hundreds in service and production still ongoing. But the J-9 fighter studied in the 1960s and 1970s, particularly the twin tail, side intake, canard delta J-9V-II, serves as an even more stark reminder of the institute’s past experience with the configuration.

Stealth shaping, on the other hand, is a much more universal and consistent trait that leaves limited room for variety. There is a finite combination of edge alignment, chines, serrations, canted control surfaces, blended wing configurations, and intake geometry, when different aircraft seek similar stealth while maintaining competitive kinematic performance. Indeed, as future stealth fighter projects emerge, includingthe South Korean KFX, the Turkish TFX, and Indian AMCA, it will likely become even more obvious how many similarities the world’s stealth fighters will share. This is likely to occur even in more advanced fifth-plus-generation projects such as Europe’s NGF, the U.K. Tempest, and Japan’s F-3.

In this author’s opinion, if the J-20 did enjoy any of the benefits of espionage in its development, the visible physical configuration and stealth shaping were unlikely to be the recipients of it.

Procurement, Upgrades, and Variants Into the Next Decade

Entering into 2021, the number of production airframes remains difficult to determine. The nuances and challenges of this been covered in a previous write-up. At the time of publishing, it is likely that at least 40 production J-20s have been built, with an upper bound of 60-70, all of which are distributed between two advanced training and tactics development units and two frontline combat units. It is notable that the most recently outfitting combat unit should be receiving J-20As in production since mid-2019, powered by the domestic WS-10 engine.

One well regarded Chinese PLA watcher did recently suggest that by 2027 (the centenary of the PLA), the number of J-20s built will “definitely” reach the F-22’s numbers and magnitude, providing an interesting minimum bound estimate – albeit a vague one – with a timeline in mind. In explicit numbers, this would translate to the possibility of at least about 200 J-20s produced by 2027. The number and timescale itself are certainly within the realm of reason, but time will tell how close this comes to reality.

The weapons suite of the J-20 will likely continue to evolve in the 2020s. The current weapons of the J-20 are the BVR (beyond visual range) PL-15, thought to have an AESA seeker as well as a dual pulse motor with an effective range of about 200 kilometers, as well as the WVR (within visual range) PL-10 with high off boresight performance and an imaging infrared seeker.

Zhuhai Airshow 2018 featured the appearance of multiple J-20s, including the astonishing display of the aircraft’s weapons bay, fully loaded with training versions of its current air-to-air suite.

It is worth noting that J-20 is unable to carry the VLR (very long range) PL-X missile, which so far has only been observed on Flanker and JH-7/A family aircraft. The PL-X missile is thought to have a range up to 400 kilometers, and would have been very appropriate for an aircraft if its role were to act as a dedicated interceptor against opposing force multiplier aircraft. The fact that J-20 was consciously designed to a size which prevented it from carrying a missile of this size should be further instructive of its role.

A recent J-20 model seemingly commissioned by AVIC has created somewhat of a stir, as it depicts not only six missiles distinctively different from the PL-15 in the ventral bay, but also a small right shoulder protrusion consistent with where an internal gun would be expected. It has been expected for over two years that a new BVR missile was in development to enlarge the J-20’s BVR magazine from four to six missiles, and a gun for the J-20 has also been long anticipated as well. Official AVIC models of aircraft are often quite detailed and depict real characteristics on the real aircraft; therefore this particular model was received with cautious gravity, with speculation if this may depict a future variant of the J-20 or a future production batch.

The J-20 will likely be integrated with a strike capability in future as well. The PLAAF is expected to select a small diameter strike weapon for the aircraft (either a new design, or one of the existing types produced by the aerospace industry for export, such as the TL-20, CM-506KG, CS/BBM2, or FT-7, among others), and a powered cruise missile similar to Joint Strike Missile and Kh-59MK2 is also being pursued, offering a secondary strike capability.

The J-20’s sensor suite and avionics will likely enjoy further improvements as advancements in electronics and software continue, but much of this will not be visually identifiable. As it stands, the visually confirmed sensor suite is appropriately present, with a large radome for a primary radar (all but confirmed to be AESA, not particularly a matter of contest these days), a chin mounted electro optic sensor in a stealthy housing, and six electro optic apertures offering at minimum a spherical missile approach and surveillance system and possibly a spherical vision enhancement function as well such as the F-35’s EO-DAS. Other key systems such as an internal electronic warfare suite, a secure high bandwidth datalink, and passive electronic support measures are impossible to visually identify but are cardinal requirements of any modern fighter developed in recent years.

The most significant subsystem upgrade the J-20 will enjoy in the 2020s is the WS-15 engine, the intended powerplant for the J-20. The fighter was designed to achieve its kinematic potential with this engine, not only in terms of maneuverability but also robust supercruise. In regards to supercruise, it is an open question as to whether the J-20 with its current interim engines (Al-31 and WS-10) is capable of a limited degree of supercruise, similar to the capabilities of F-35s and some fourth-plus-generation fighters. This will likely never be conveyed via official channels, but could be potentially gauged if weight numbers are ever provided.

As engines are one of the most closely guarded domains of PLA projects, there has been few rumored updates regarding the progress of the WS-15. However, there are tantalizing suggestions in recent years that the progression and maturation of Chinese engine development and testing regimes has shortened the time needed between installation of a powerplant on its destined platform and certification for entry into service. In practice, there is a likelihood that the time between first installation of a WS-15 into a J-20 and the entry of WS-15-powered J-20s into service will be significantly shorter than past experiences such as the WS-10 in aircraft like the J-11B.

This author has also written of the prospects of a twin seater J-20, and brief mentions in passing from some Chinese language insiders suggest this aircraft is still anticipated. It remains to be seen if the twin seat J-20 will enjoy significant structural changes beyond the addition of a second, tandem cockpit, such as a larger weapons bay or enlargement of the aircraft’s overall dimensions.

The Big Picture

The past 10 years have seen the J-20 start and complete its testing and trials, begin production, enter service with initial training and evaluation units, achieve operational status in frontline combat service, and also achieve frontline combat service with a domestic engine. For a nation’s first take on a stealth aircraft, let alone a fifth-generation fighter, this progress is undeniably impressive, and in terms of program execution, production, and maturity, the J-20 compares favorably to another fifth-generation fighter that flew a year earlier – the Russian Su-57.

The high level of PLA OPSEC means it may be many years until the various details, milestones, and challenges experienced by the J-20 over its first decade are revealed or displayed to the general public, and there are many aspects of the aircraft that will never be made known to the outside world.

Considering all of the above together, it is nevertheless very reasonable to state that the aircraft is sufficiently mature to have achieved a minimum credible combat capability – though of course as with all new aircraft types, it will likely experience hiccups along the way, which will be nevertheless be solvable with money and technical persistence. While the lack of the WS-15 restricts the aircraft from achieving its full kinematic potential, the J-20 at present remains easily the most capable air superiority platform in service with the PLAAF. Even compared to the F-22 and F-35, it offers a unique combination of kinematic, range, endurance, and weapons and sensor profiles.

Going into its second decade, production of WS-10-powered J-20As will likely continue to accelerate, before being superseded by production with the WS-15 once it is ready. Barring unforeseen acts of divine intervention, it is likely that the end of the decade will see the J-20 produced in numbers meaningfully exceeding that of the F-22’s production run and claim the status as the world’s second-most produced fifth-generation fighter after the F-35.

Development and integration of strike weapons will allow the J-20 to serve in a strike and limited maritime strike role if required, while newer air to air weapons will further enhance its primary air superiority mission. Iterative improvements of its avionics suite and maturation of a robust fifth-generation logistics and maintenance backbone will further support its overall capability and readiness. In the event of conflict, the operational and tactical use of J-20s would likely depend on the caliber of the opposing force and the fleet size and maturity of the aircraft – a fleet of 40 J-20s would be applied quite differently to a fleet of 200 J-20s.

The above will all be complemented by the emergence and subsequent entry into service of additional stealthy aircraft later this decade, including the H-20 bomber, the FC-31-derived carrier-borne fifth-generation fighter, stealthy unmanned combat aerial vehicles, and the expected twin seat J-20. It is also plausible that the first demonstrators and prototypes of the PLA’s sixth generation efforts will emerge by the close of the decade as well.

In hindsight, the timing of J-20 was in many ways fortuitous for PLA watching.

Prior to the J-20’s emergence, the ex-Varyag had yet to be credibly refitted and successor carrier projects were far from concrete. Destroyer production was indecisive, with only a restart of 052C production apparent without a definitive 052D successor confirmed, and the prospect of a ship like the 055 emerging a few years down the line was not even entertained. Expectations for a strategic transport aircraft, a medium-weight stealth fighter, and fourth-plus-generation fighter production were murky and in flux. The commissioned fleet of AEW&C, EW, and other special mission aircraft was modest and further expansion was not confirmed. Amphibious assault ship ambitions appeared minor, with only two 071s produced and no helicopter carriers on the horizon. Whispers of a carrier-borne fifth-generation fighter, stealthy UCAVs, and a strategic stealth bomber seemed like fantasy.

The revelation of the J-20 in the complete form that it emerged in overnight elevated the threshold of what constituted “reasonable expectations” from the Chinese military industrial complex in virtually all domains. Though few knew it at the time, the years after 2011 would be characterized by the successive emergence of new boxes, that would become inevitably ticked off over time.

Ten years on, J-20 remains the aircraft that changed PLA watching forever.