J20 Stealth Fighter

johnq

Senior Member
Joined
May 30, 2009
Messages
1,385
Likes
2,784
A lot of people confuse WS-10 engine on prototypes at airshows as the same as the engine on operational aircraft. The fact is that the WS-10 (all variants) thus far only last 30 hours before needing maintenance. So it is impossible to put such an engine on operational aircraft:
Early revisions of the resulting WS-10 engine have fallen well short of design goals which aimed to match the Su-27’s AL-31 engine on thrust output and reliability. Overhauls were required every 30 hours, versus 400 hours for the Russian benchmark. Anecdotal evidence suggests the WS-10 also takes longer to produce thrust.
The fact is that the entire PLAAF is flying on older, less reliable Russian engines, because the WS-10 engine's variants are simply not reliable enough to field on operational aircraft, as they need maintenance after every 30 hours, which is a nightmare in war-time. The WS-10C is nowhere near to being put on operational aircraft, even according to Chinese sources. It's much more likely that the PLAAF is using the appearance of WS-10C engines as leverage to get better technology engines from Russia. Otherwise how can a new working engine just appear out of nowhere when the PLAAF's WS-10B engine only lasts 30 hours? Just imagine the PLAAF using the Russian AL-31 engines on the J-20 for the last decade in spite of it being overweight for those engines by 3000 to 4000 kg even compared to a 1970s era SU-27! That shows a great deal of desperation on the part of the PLAAF, and indicates that the WS-10 is a complete failure. That is why I know that the PLAAF is just using the WS-10 at airshows for propaganda purposes, as it is simply too unreliable (only lasts 30 hours) to use on operational aircraft.
The J-20 RCS (radar cross section) is too great to avoid detection even from the front because the PLAAF has not figured out a way to hide the J-20 radar, radome, canopy, canards, optronics sight and other high RCS features from enemy radar, which is why the J-20 was detected and tracked by SU-30MKI radar from hundreds of kilometers away over the Himalayas. The use of high RCS Russian engines also increases the J-20 RCS, because just having an S-bend inlet is not enough to completely mask the reflection from the engine front, and China currently does not possess the technology to make a working low RCS engine.
The radar and avionics on the J-20 are primitive as they are copied from 2 decades old, severely downgraded (for export to China) avionics of the SU-35, which is why China keeps importing SU-35s from Russia, in spite of the PESA radar on the SU-35: This level of radar on the J-20 will be easily jammed by western, Russian and Indian ECM. The radars of the J-20's missiles are also copied from 2 decades old, severely downgraded (for export to China) Russian missiles, and will also be jammed by western, Russian and Indian ECM.
 
Last edited:

MiG-29SMT

Regular Member
Joined
Jan 12, 2020
Messages
588
Likes
826
Country flag
The intake is exposed to radar, which is quite bad for stealth. All F22, F35, J20 don't use such desgin.

View attachment 73784

View attachment 73785

This is how F22 deal with it.

View attachment 73786

Check out those details:

View attachment 73787


View attachment 73788

After 10 years, it realize it and did some compensation:

View attachment 73789

View attachment 73790
this will help you to understand F-22, Su-57 and J-20

THE COLD SECTION AIR INLET DUCTS  The air inlet duct is technically a part of the airframe, but it is so important in the development of thrust that it is included with the engine as a part of the cold section.  The air inlet duct must supply uniform flow of air to the compressor so that it can operate stall free.  It must produce as little drag as possible.  If taken only a small obstruction to the air flow inside the duct to cause a significant loss of efficiency.  Inlet cover must be installed to prevent damage or corrosion in this vital area.


SUPERSONIC INLET DUCT  The air approaching the compressor inlet must always be at speed below the speed of sound.  when an aircraft is flying at supersonic speed, the inlet air must be slowed down to subsonic speed before it reaches the compressor.





As tactical aircraft design evolved in the 1990s, compact inlet ducts became another technology of emerging interest due to the desire to enable lower cost through lower inlet length. In this context, “compact” refers to short inlet ducts (L/D ∼ 4) that achieve full line‐of‐sight obscuration of the engine, which is necessary for survivability compliance. Unfortunately, achieving full obscuration in a compact design requires high rates of duct curvature and flow area/shape change, all of which traditionally introduce unacceptable pressure loss and distortion. However, through the use of modern design techniques, researchers were able to develop and validate with wind tunnel experiments compact designs that achieved excellent performance (see Philhower, Robinson and Brown, 1998).

1610771659069.png

See the author says benign inlet duct, because has very little curvature, basically is straight


Su-57 has relatively a benign inlet duct it has some curvature but is not like in F-22, they reduced inlet duct length thus Sukhoi reduced weight.
1610771853082.png

1610772311039.png

F-22 has a compact inlet duct with a lot of curvature
1610772138712.png


1610772343178.png

F-35 is the same has a lot of curvature.

1610772537667.png


J-20 has a longer inlet duct than F-22, having a longer duct means more materials a heavier inlet duct but perhaps less curvature.

The Su-57 tried to avoid weight by using a inlet blocker and a relatively benign inlet duct.

F-22 reduced the inlet duct because F-22 uses heavy 2D nozzles so a short inlet duct compact enough was a must.

By design you can see China is not willing to use a 2 D nozzles like F-22 because the inlet is quiet long adding lots of weight, so contrary to F-22 they will not add heavier flat nozzles.

So J-20 has to do area rule but with lesser wing-fuselage blending than F-22.
 

Kumata

Senior Member
Joined
Feb 27, 2019
Messages
3,159
Likes
10,785
@MiG-29SMT you are wasting your time on a CCP troll. Good thing is they are good at subverting the topic to suit their agenda..


I am sure he is trying to get the result of those mathematical calculations and make some thing out of it..you have put whole CCP propoganda deptt to work Dude :crying: :crying:

Head over to Chinese CV 16 thread where a bluberry wearing bikini colleague of rockdog was making claims that laoning or whatever does 32 knots with a steam engine .. she does't know what knots / what propulsion is.... For comparison USS Nimitz does 31.5 knots with 2 nuclear reactors fed propulsion....

Looking at videos the arrestor hook is barely able to stop the jet and it goes to edge of deck but they are happy to post pic of buffet on carrier deck with jets in back ground... Seriously !!!!!!!!!!!!!!1
 
Last edited:

rockdog

Senior Member
Joined
Dec 29, 2010
Messages
1,060
Likes
544
Country flag
So far, this is the best article about the review of J20 and Chinese military industry for last ten years.

------------------------

The Diplomat: 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.



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.

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.

Enjoying this article? Click here to subscribe for full access. Just $5 a month.

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.

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.

Enjoying this article? Click here to subscribe for full access. Just $5 a month.

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.
 

rockdog

Senior Member
Joined
Dec 29, 2010
Messages
1,060
Likes
544
Country flag
@MiG-29SMT you are wasting your time on a CCP troll. Good thing is they are good at subverting the topic to suit their agenda..


I am sure he is trying to get the result of those mathematical calculations and make some thing out of it..you have put whole CCP propoganda deptt to work Dude :crying: :crying:

Head over to Chinese CV 16 thread where a bluberry wearing bikini colleague of rockdog was making claims that laoning or whatever does 32 knots with a steam engine .. she does't know what knots / what propulsion is.... For comparison USS Nimitz does 31.5 knots with 2 nuclear reactors fed propulsion....

Looking at videos the arrestor hook is barely able to stop the jet and it goes to edge of deck but they are happy to post pic of buffet on carrier deck with jets in back ground... Seriously !!!!!!!!!!!!!!1
No interest go personal with you, enjoy urself. I am member here 10 yrs now, you are not the first one wanted to waste my time.
 

MiG-29SMT

Regular Member
Joined
Jan 12, 2020
Messages
588
Likes
826
Country flag
So far, this is the best article about the review of J20 and Chinese military industry for last ten years.

------------------------

The Diplomat: 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.



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.

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.

Enjoying this article? Click here to subscribe for full access. Just $5 a month.

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.

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.

Enjoying this article? Click here to subscribe for full access. Just $5 a month.

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.
The control-canard was the first to be analyzed. For some designs, aircraft with control-canard can have high maneuverability due to the inherent destabilization of the aircraft by the canards. A control-canard can also counteract pitch-up moments due to tip stall by having significant nosedown deflection. This fact can be used to optimize the wing’s aspect ratio and wing sweep. Close coupling to the wing also allows for directed airflow over the wings at high angles of attack to provide more lift, reduce drag, and delay stall. These attributes are especially helpful in supersonic delta wing configurations in transonic and low-speed flight regimes such as landing and takeoff. However, the use of a control-canard does come at some cost. The large, angular surface can have a negative impact on stealth characteristics due to the tendency to reflect large amounts of radar signals forward. There can also be adverse flow disturbances from the canard over the wing.

1610796112882.png


The advantages of a tailless aircraft include the removal of a horizontal stabilizer which contributes to a smaller RCS due to its sleeker profile [6]
1610796083315.png


However, disadvantages exist as well for the delta wing and include high induced drag and high energy bleed-off in rapid turns. A more specific type of delta wing is the cranked arrow which has two sections of the wing swept at two different angles. This reduces drag compared to the full delta wing and allows for landing at lower speeds [


By last, canards can potentially have poor stealth characteristics due to their large and angular surfaces that tend to reflect radar signals forwards
 

Kumata

Senior Member
Joined
Feb 27, 2019
Messages
3,159
Likes
10,785
No interest go personal with you, enjoy urself. I am member here 10 yrs now, you are not the first one wanted to waste my time.
you came from CCP HQ's with such a long useless para :rofl: :rofl:
 

MiG-29SMT

Regular Member
Joined
Jan 12, 2020
Messages
588
Likes
826
Country flag
The F-35 is reported to have a radar cross section (RCS) of 0.001 square meters from a narrow frontal aspect. This is the size that the F-35 appears to be on certain radars, despite its physical size, and is roughly equivalent to the size of a small ball bearing or insect. At 0.001 square metres, the Su-35 will detect the F-35 at 25 nautical miles – with an altitude advantage and the ability to turn away. As the IRBIS-E radar of the Su-35 looks 240 degrees around the nose, this can allow the Su-35 to shoot a BVR missile, when the F-35 cannot. However, the F-35’s low-observable radar signature has “some gaps in coverage,” particularly when viewed from the sides, rear, bottom, or top for which a ten-times larger RCS of 0.01 square meters or larger has been reported. In other words, detection of the F-35 will be most difficult in head-on engagements and less difficult from other angles. By comparison, the F-22 is reported to have a smaller RCS of 0.0001 square metres. But the returns on the kind of stealth technology employed by the F-35 are being diminished by advances in radar technology. The low-observable technology on the F-35, and to a lesser extent the F-22, is designed to be effective against radar operating in the X-band range and at shorter wavelengths. The rationale behind this decision was that X-band radars detect aircraft with a high degree of accuracy and, as a result, are used to provide fire-control information to anti-aircraft missiles to engage targets. However, the same properties that make the F-35 stealthy against X-band radars do not apply as effectively to lower-frequency radars that operate on longer wavelengths. Lower-band radars are widely employed as surveillance radars to provide early detection of incoming targets at ranges that typically exceed those of Xband systems. Since lower-band radars detect targets with less accuracy, they were traditionally considered unsuitable for providing fire-control information to engage targets. The effectiveness of such radar systems to target aircraft was demonstrated in 1999 when an American F-117A Nighthawk stealth attack aircraft (RCS of 0.003 square meters) was shot down by Yugoslav forces using a modified VHF radar model that was introduced in 1970. The same SAM battery mission-killed another F-117 as well. This is why the Su-35S and the T-50 have L-Band radar in the wing leading edges.


If the enemy uses very-high-frequency and high-frequency radars, the value of stealth is heavily reduced if not eliminated altogether – as shown by the F-117 shot down over Serbia only 18 seconds after being discovered by the very-high-frequency radar, and another F-117 that was mission-killed by the same surface-to-air missile battery. The latter F-117 returned to base but was damaged beyond repair. The Russian T-50 appears to be optimized to shoot down US fighter aircraft, primarily the F-22 and F-15. China’s J-20 is more optimized for shooting down US airborne-warning-and-control aircraft, transport and tanker aircraft, thus neutralizing relatively short-range US fighters without having to engage them in combat at all. The F-22 is a compromise between two roles. The J-20 is meant to avoid aerial combat though it should be able to handle itself if it comes to that.

The Eurofighter Typhoon’s infrared-search-and-track sensor can detect subsonic fighters at 90 kilometres from the front and at 145 kilometres from the rear. The jet engines themselves are very hot and they heat up the airframe surrounding it. Apart from the engines and their exhaust, they are a number of other sources of infrared radiation from an aircraft.



source
Submission to the Joint Strike Fighter Inquiry
David Archibald F-35 Submission
 

J20!

Senior Member
Joined
Oct 20, 2011
Messages
2,619
Likes
1,247
Country flag
Where are the mods on this sub forum? We regularly get trolls who have no input other than stupid and racist comments. Case and point being @Kumata

Please clean both the J20 and CV17 thread and let's get back to actual news and analysis.

Otherwise this whole subforum will devolve into nonsense flame wars which is why I stopped posting on this forum in the first place.
 

Kumata

Senior Member
Joined
Feb 27, 2019
Messages
3,159
Likes
10,785
Where are the mods on this sub forum? We regularly get trolls who have no input other than stupid and racist comments. Case and point being @Kumata

Please clean both the J20 and CV17 thread and let's get back to actual news and analysis.

Otherwise this whole subforum will devolve into nonsense flame wars which is why I stopped posting on this forum in the first place.
Before blaming me .. you started it words like idiot..et all... i know u chinese bots are not taught manners but learn to be civil on forums... learn basic etiquettes and than complain...there are no free lunches.....

and trolls need to be trolled... thats what they deserve specially when they start doing name calling...

Enjoy your blu berry doll on coal fed steam propulsion... i learn hot steam is good for alleviating Chinese virus....
 

johnq

Senior Member
Joined
May 30, 2009
Messages
1,385
Likes
2,784
Rick Joe, the writer of the Diplomat article of J-20 above, has always repeated PLAAF propaganda blindly without realizing that much of what the PLAAF puts out in terms of J-20 performance is a fiction created to brainwash Chinese people. The Diplomat is also known for printing paid CCP propaganda articles regularly.
 

J20!

Senior Member
Joined
Oct 20, 2011
Messages
2,619
Likes
1,247
Country flag
Rick Joe, the writer of the Diplomat article of J-20 above, has always repeated PLAAF propaganda blindly without realizing that much of what the PLAAF puts out in terms of J-20 performance is a fiction created to brainwash Chinese people. The Diplomat is also known for printing paid CCP propaganda articles regularly.
The PLAAF has not released any data at all on the J20. Range, max speed, weapons load etc have never been disclosed by the PLAAF or the manufacturer Chengdu. So I fail to see what "propaganda" you're referring to. Please provide this PLAAF data if you have it. I'd be very interested in seeing it.

Rick Joe and other analysts like Andreas Rupprecht monitor open source material and post numbers, sightings and the evolution of the airframe from prototype 2001 in 2011 to the serial production airframes being inducted now.

The diplomat has been posting anti China articles for years. So I fail to see how they are suddenly CCP puppets because they hired Rick Joe to post articles on Chinese platforms.
 

johnq

Senior Member
Joined
May 30, 2009
Messages
1,385
Likes
2,784
I was talking about the engine. These "China watchers" bought Chinese propaganda about WS-10 being on operational J-20 for a decade, while those of us who did some research knew that the J-20 has been using Russian AL-31 all along because the WS-10's variants are not reliable enough to put on operational aircraft. He was wrong about that for about a decade, because he believed CCP propaganda claims about the J-20, WS-10, etc.
 

J20!

Senior Member
Joined
Oct 20, 2011
Messages
2,619
Likes
1,247
Country flag
I was talking about the engine. These "China watchers" bought Chinese propaganda about WS-10 being on operational J-20 for a decade, while those of us who did some research knew that the J-20 has been using Russian AL-31 all along because the WS-10's variants are not reliable enough to put on operational aircraft. He was wrong about that for about a decade, because he believed CCP propaganda claims about the J-20, WS-10, etc.
You're confusing Rick Joe for fan boys on PDF or other forums. And again please provide this "propaganda" from the CCP you're referring to, because neither the party, nor the PLAAF has released even the most basic information about the J20, let alone the engines it uses.

And also, kindly show us RICK Joe's posts from "a decade" ago claiming the J20 flies with WS10 turbofans since I am on SDF with him and have never seen the posts or articles you alude to. Stop generalizing.

Secondly, the initial J20 prototypes to the LRIP airframe and the first batch of J20s were using AL31F' s. That's not disputed.

However, since mid 2019, every new build J20 leaving the facilities at Chengdu Corp has been using WS10C's. That is just a fact...

But if you have images that prove the opposite, please provide them to us.

And lastly, in response to your posts above about J20s flying with WS10s at Airshow, please post a few pics to prove it; because to the best of my knowledge, all the J20's that performed at the Zhuhai Airshow were flying on AL31F's.

And you keep claiming that WS10B and C turbofans have lifespans of 30 hours. Please show us the receipts mate. Citation needed, because even new build J10C's are being equipped with WS10B's now.
 
Last edited:

johnq

Senior Member
Joined
May 30, 2009
Messages
1,385
Likes
2,784
Early revisions of the resulting WS-10 engine have fallen well short of design goals which aimed to match the Su-27’s AL-31 engine on thrust output and reliability. Overhauls were required every 30 hours, versus 400 hours for the Russian benchmark. Anecdotal evidence suggests the WS-10 also takes longer to produce thrust.
Initial production models of China’s latest J-20 stealth fighter used the upgraded WS-10B, but production models appear to still rely on Russian Saturn AL-31 engines.
This is because the PLAAF found the WS-10B to be too unreliable, hence reverting to AL-31 engines for the J-20 in spite of it being 3000 to 4000 kg too heavy for the dry thrust provided by the engine.
It is a fact that the WS-10 engine and its derivatives are too unreliable to use on PLAAF production fighters, which is why the entire PLAAF ( 3rd generation plus) currently flies with Russian engines. Everything else is propaganda being sold by CCP bots.
 

Kumata

Senior Member
Joined
Feb 27, 2019
Messages
3,159
Likes
10,785
Aha.

Now that we all agree that nobody have any data about J20, I see this whole thread itself is propaganda filled with speculation!!!!!!!!!!!

Mods .. time to close this thread
 

J20!

Senior Member
Joined
Oct 20, 2011
Messages
2,619
Likes
1,247
Country flag
"Early versions" of the WS10. WS10A's started flying on J11B's in the 2000's mate. Right now we're discussing WS10B and WS10C being fielded on new build J10C, J16 and J20 respectively. So why are you referring to news that is almost 20 years old?

And you still haven't showed us any info released on the J20 by the CCP or PLAAF. Where are the articles by Rick Joe claiming the J20 has been flying with WS10C's for "a decade"? And who is that Sébastien fellow? Because that is not Rick Joe.
 

johnq

Senior Member
Joined
May 30, 2009
Messages
1,385
Likes
2,784
That article is from 2020 and it clearly states that the J-20 is still using AL-31 engines. This means that you were wrong when you stated that the 2019 J-20 used the WS-10.
There is a difference for engines on aircraft being flown for their propaganda photo sessions versus what is actually on operational aircraft. And it is a fact that the PLAAF still uses Russian engines on all its operational aircraft; the rest is propaganda created to brainwash Chinese people. Those of us who know what to look for can tell the difference.
 

Latest Replies

Global Defence

Articles

Top