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Monday, October 26, 2015

PLAAF Fighter Modernization & J-20 Updates

Image 1: J-11A fighter aircraft.

As part of the "Countering Foreign 5th Generation Threats" series, this article will focus on broader trends within the PLAAF fighter force with respect to preparing for local wars under "informatization" conditions in the 2020 to 2030 time frame.

For information on specific types of PLAAF fighter aircraft and avionics, please refer to the following articles:

China's Anti Access Strategy Part II: Air Power
The Technological Maturity of Chinese AESA Technology & Strategic Impacts
Threat Analysis of Foreign Stealth Fighters: Shenyang J-31 Part I
Threat Analysis of Foreign Stealth Fighters Part III: J-31 Part II

Equipment Modernization

The current composition of the PLAAF's fighter and interceptor fleet demonstrates both the progress and complexity of China's modernization effort since the 1990s. The current fleet contains approximately 1,200 fighter and interceptor aircraft of which 60% are third generation platforms such as the J-7 which is a domestic copy of the Mig-21 (Coredsman & Yarosh, 2012). While variants of the PLAAF's third generation aircraft incorporate significant upgrades, they are largely obsolete relative to Japanese and US fighter aircraft. Most of the PLAAF's third generation fighter force will be retired over the course of this decade and replaced by much more capable fourth generation aircraft such as the J-10 and J-11.

As of 2014, the PLAAF fields 200 J-10A aircraft and roughly 300 Flanker derivative aircraft including the J-11A, J-11B, Su-27SK, Su-27UBK, and Su-30MKK (Flight Global World Air Forces, 2014). Production of these fourth generation aircraft by Chengdu and Shenyang is likely to accelerate over this decade to facilitate the replacement of the J-7 and J-8. Chengdu is expected to produce 200 J-10 aircraft over the next five years with at least 30 of the more advanced J-10B variant being produced each year (Fisher, 2015). According to the International Institute for Strategic Studies report The Military Balance for the years 2012 and 2014, the PLAAF and PLANAF added an additional 88 J-11B aircraft to their fighter forces within a two year period. While most literature on the PLAAF acknowledges the shift from third generation to fourth generation platforms, the substantial performance disparity among the new fourth generation aircraft is frequently overlooked.

Image 2: Fighter Radar Specifications

By Western standards, much of the PLAAF's current fourth generation fleet is not modern. For example, the N001, N001VE, and Type 1493 mechanically scanned radars equipped on the PLAAF Flanker fleet is comparable to 1980s US systems. The major limitation of these older mechanically scanned arrays is the PLAAF cannot fully utilize its numerical superiority as its fighter radars are limited in their ability to simultaneously track and engage multiple targets and provide situational awareness. Modern active electronically scanned array (AESA) radars will enable 4.5 generation and fifth generation PLAAF fighters such as the J-10B, J-11D, J-16, and J-20 to fully utilize their large payload capacity for effective beyond visual range (BVR) missile salvos. The PRC has made significant progress in domestically produced BVR missile technology with the development of the PL-15. The PL-15 is powered by a ramjet which grants it an improved no escape zone and at least a 60 mile range; the missile also features an active seeker and two way data-link. Chief of Air Combat Command, General Herbert "Hawk" Carlisle indicated that fielding longer range missiles to out range the PL-15 is "an exceedingly high priority". General Carlisle's remarks are especially stark as it is not customary for USAF officials to publicly refer to specific systems developed by potential adversaries (Axe, 2015).

Image 3: Concept art of a FC-31/J-31 launching a PL-15.

In addition to modern AESA radars, PLAAF 4.5 and 5th generation aircraft will also field greatly improved electronic warfare and countermeasure systems. In March of 2015, Richard Fisher from IHS Jane's reported the addition of new missile approach warning systems (MAWS) on J-11A aircraft. The combination of both the PLAAF's willingness to acquire significant numbers of new fourth generation aircraft and upgrade its existing fourth generation fleet has significant implications on the number of fifth generation aircraft the PLAAF is likely to field over the next decade.

PLAAF 5th Generation Developments - J-20 & J-31

Image 4: Design alterations between the first and third J-20 airframes are clearly visible including the nose cone, diverterless supersonic inlets (DSI), and the possible inclusion of radar absorbent material coatings (RAM). The latest J-20 airframe designated 2016 includes an expanded fuselage towards the engines such that less of the unstealthy nozzles are exposed and an expansion of the DSI (Feng, Lin, & Singer, 2015).

Despite the recent media attention about China's stealth fighter programs, the bulk of China's air superiority capability will consist of non-stealthy 4th generation aircraft for at least another decade. The J-20 is expected to enter service between 2017 and 2018. Given the limited information within the public domain, the J-20 program appears to be progressing well as a total of seven prototype aircraft have been built since the initial debut in 2011 (Feng, 2015). The more recent J-20 airframes such as numbers 2011, 2012, 2013, 2015, and 2016 show a progression towards a stealthier production aircraft equipped with a large AESA radar and EOTS-89 electro-optical targeting system (EOTS). While externally impressive, the photographs of the new prototypes do not reveal the extent in which Chinese firms involved in the production of the J-20's avionics been able to write software that will effectively fuse the J-20's sensors to provide enhanced situational awareness. As the US F-35 program has demonstrated, the development of internal systems and software has generally been a more daunting task than the development of a low observable airframe.

Three main theories exist among Western defense/aerospace publications with respect to the role of the J-20, each has different implications on the number of J-20 aircraft the PLAAF is likely to acquire. The first theory is strait forward, the PLAAF has a history of fielding both low-end and high-end fighter aircraft and it is likely the J-20 will fill the air superiority high-end role (Gary Li, 2012). Two issues hinder the J-20's current utility as a high-end air superiority fighter: (1) its lack of sufficiently powerful engines and (2) its exposed engine nozzles. Current prototypes use a pair of imported AL-31F engines from Russia which produce a maximum of 27,500 pounds of thrust each compared to the estimated 70,000 pound plus weight of the aircraft will a full load of fuel and munitions. Bill Sweetman argues the lack of rear aspect stealth is likely an intentional design choice based on the assumption that high speed stealth aircraft can tolerate a relatively higher aft radar cross section (rcs). Assuming the J-20 receives adequate engines, proponents of the high-end fighter theory argue the J-20's delta wing canard airframe will grant it exceptional maneuverability and high angle of attack capability. If the J-20 serves as the high-end component of the PLAAF fighter force, a final production run of at least a few hundred airframes is plausible.

Image 5: J-20 weapons bay door on the second prototype aircraft designated 2002. Along with the two side bar doors which can carry one IR guided missile each, the J-20 has the capacity to carry at least six air-to-air missiles.

The second theory argues the J-20's design attributes such as its large internal fuel capacity, AESA radar, large internal weapons bay, and relatively small wings indicate the J-20 is optimized as a stealth supersonic interceptor. Karlo Kopp and Peter Goon of Air Power Australia argue the J-20's design traits would make it an ideal platform to target AWACS, C4ISR, electronic warfare, and tanker aircraft within the first and second island chains. Bill Sweetman also finds the stealth interceptor role convincing noting that,
The U.S. has committed its armed forces to concentrate much of their funding on tactical fighters with a combat radius of 600 mi., much less than the distance from their bases to targets on the Chinese mainland, and has persuaded its allies to do the same. As a result, operations are almost entirely dependent on two groups of aircraft: tankers and large intelligence, surveillance and reconnaissance (ISR) aircraft with long endurance. Under the 'distributed control' concept favored by U.S. Air Force commanders as a hedge against electronic warfare, including cyberattacks, the ISR aircraft also have a control-and-communications function. However, both tankers and ISR aircraft are vulnerable to attack, and maintaining a defensive combat air patrol (CAP) over them at long range is also difficult.
By targeting the enablers of US power projection in the Western Pacific, the J-20 would assist in denying the US the ability to sustain operations in the vicinity of China as part of a larger PRC A2/AD strategy. If the J-20 serves as a stealth interceptor, the niche role within the PLAAF would presumably require less aircraft than the high-end fighter role.

The third theory is that the aircraft is optimized as a air-to-ground strike aircraft given its large internal fuel and payload capacity. The J-20 would penetrate through US & Japanese air defenses and strike targets within the first and possibly second island chain. Propoents of the strike bomber theory argue that the J-20 would be a useful complement to the larger non-stealthy H-6. While the H-6 bomber has the range to strike targets within the first and second island chains, its large radar cross section would not enable it to deliver precision guided munitions in a highly contested environment; the H-6 would be forced to utilize stand-off weapons such as cruise missiles.

Of the three theories, the stealth interceptor role is the most plausible in the short-term given the lack of high performance domestically produced jet engines. Over the long-term, it is likely that domestic development of a high performance turbofan engine will enable the J-20 to become a formidable air superiority aircraft capable of fulfilling both the high-end and stealth interceptor roles in the PLAAF fighter force.

Image 6: FC-31 EORD-31 IRST sensor. Chinese media sources claim the EORD-31 can detect an F-22 at a range of 110 km (60 nm) and the B-2 at a range of 150 km (81 nm). These claims are highly suspect and are unlikely to be accurate given the verified performance figures of high-end IRST systems such as the Eurofighter's PIRATE IRST which has a range of approximately 50 km.

Since the first images of the J-31 became publicly available in 2012 until 2014, speculation has dwarfed known verified information regarding the aircraft's potential role as a low-end compliment to the J-20 or even as a carrier based aircraft. Since 2014 were the J-31 participated at the Zhuhai airshow, much more information on the aircraft has entered the public domain. It is now apparent the assumption that the J-31 would serve as a low-end compliment to the J-20 should be seriously questioned on the basis that it is unlikely the aircraft will enter domestic use within either the PLAAF or PLANAF. Shenyang consistently refers to the aircraft as the FC-31 which is an export only designation. The different public treatments between the J-20 and FC-31 by the PLAAF is indicative of their different roles:
What looks like a thoroughly modern stealth fighter is apparently not good enough to serve as China's next medium-weight combat aircraft...The J-20 was revealed in late 2010 and appears to have made its first flight in January 2011. It was not promoted at Zhuhai. And therein lies a key piece of evidence of the status of the J-31. The J-20 was not at Zhuhai because it is not for sale and because China does not want to reveal too much about it. It is intended for the Chinese air force. Conversely, because the J-31 was exhibited at Zhuhai and is promoted as an export product, the Chinese air force obviously does not want it.- Perrett, Hewson, Johnson, & Sweetman, 2014
The disparity in secrecy between the FC-31 and J-20 programs was clearly visible in September of 2015 when the F-31's performance data was leaked. Despite the inclusion of potentially sensitive information such as the jet's combat radius, Chinese internet censors did not deem the release of FC-31 performance specifications to be damaging enough to warrant action (Fisher, 2015). Given the extensive increase in fourth generation fighter production and substantial investments in new fourth generation upgrades, it is likely the PLAAF is content with its fourth generation aircraft serving as the low-end compliment to the J-20. Given the state of the PLAAF's current fighter inventory, the decision to adopt fourth generation aircraft as a low-end compliment to the J-20 rather than pursue a pure fifth generation fighter fleet is a prudent management of risk. Furthermore, the mass production of relatively inexpensive fourth generation aircraft is desperately needed by the PLAAF to facilitate the rapid retirement of the third generation J-7 and J-8.

Part III will discuss improvements to PLAAF training and tactics as well as PRC knowledge of American capabilities as a result of cyber espionage. Lastly, an analysis of PLAAF modernization challenges and current shortfalls will be presented. Part IV will discuss the growing importance and role of passive senors in a mixed fourth-fifth generation dogfight.

Sources (In Addition to Part I)

  1. J-20 Stealth Fighter Design Balances Speed And Agility, Bill Sweetman, 2014.                  
  2. Beijing tech show highlights advances in Chinese fighter sensors, Richard D Fisher Jr, 2015.
  3. Images suggest J-10Bs close to entering Chinese service, Richard D Fisher Jr, 2015.
  4. China showcases new weapon systems at 3 September parade, Richard D Fisher Jr, 2015.
  5. Images suggest upgrades to China's early series J-11s, Richard D Fisher Jr, 2015.
  6. USAF seeks ‘interim’ CHAMP, longer-range air-to-air missiles, James Drew, 2015.
  7. MAKS: Chinese firm unveils new sensors for J-20, J-31, Stephen Trimble, 2015. 
  8. PLA Air to Air Missiles, Karlo Kopp, 2012.                                                                         
  9. The New Chinese Missile That Has the U.S. Air Force Spooked, David Axe, 2015.
  10. CHINESE AIR-TO-AIR MISSILE HITS TARGETS, SPOOKS USAF GENERAL, P.W. Singer & Jeffry Lin, 2015.                                                                                                     
  11. 6TH J-20 STEALTH FIGHTER ROLLS OUT, MORE TO SOON FOLLOW, P.W. Singer & Jeffry Lin, 2015.
  13. China Developing a 2nd Stealth Fighter?, J. Michael Cole, 2012.                                        
  14. China's Expert Fighter Designer, Robert Beckhusen, 2015.
  15. Chengdu J-XX [J-20] Stealth Fighter Prototype A Preliminary Assessment, Karlo Kopp & Peter Goon, 2011. 
  17. Sky Searchers, 2014.
  18. Shenyang FC-31 fighter performance 'leaked' online, Richard D Fisher Jr, 2015. 
  19. J-20 and more thoughts on 5th generation projects, Feng, 2015.                                         


  1. Hay Matt

    What do you think of the new Stealth boomer announcement.

    Stone 30.

    1. Hi Stone,

      I'm glad Northrup Grumman won but I expected the Lockheed-Boeing team to win. Both teams have excellent experience but the Boeing-Lockheed team has 5 times the revenue of Northrup and could have spent them into the ground in terms of reduced cost for the first few airframes. I suspect Northrup's work on the B-2 and RQ-180 played a big role in their victory and the US desperately needs the LRS-B as most of our fighters don't have the range they need. Still I'm not that convinced by the argument we need to cut F-35 to buy more LRS-B. At least wait for the F-35 to reach efficiency of production in the 2019-2021 range with $85 M per airframe before that decision is made.USAF will definitely require more than 100 bombers regardless, I've seen estimates in the 150 to almost 200 range. Overall, I'm pretty confident in the program as the USAF sent its A-team of acquisition officials to handle the program and the requirements haven't shifted in years which is key. The death spiral of programs often results from changing and ill-founded requirements.

      Do you think Australia will join the US in the South China Sea FON ops?



    2. Hi Matt

      Thanks for the response.

      I think we will Join, without question.

      150-200 LRS-B, for what reason. There is no need, if it gets to that stage the rockets will be flying and the nukes will be dropping. Before the LRS-B will even come into play.

      By that stage it's game over. There is no way that Russia or China will allow 1 LRS-B in it's air space without lunching at least 50-100 ICBM. Once that happens there will be no need for the LRS-B

      Between 25-50 will be more than enough LRS-B. Don't wast the Tax payers $$$.

      Subs and ICBM will determine the fate of the world in that senerio not any aircraft.


    3. LRS-B's primary mission will be conventional rather than nuclear. The use of nuclear capable assets in war for conventional missions is an over hyped factor by arms control groups e.g. the B-2 was utilized in Kosovo and Iraq and nobody thought the US was nuking anyone. The LRS-B has the range, payload, and VHF stealth to hit targets in mainland China from the continental United States which no other asset aside from the B-2 can. Furthermore, we desperately need to replace the B-52 and B-1 which would have very little utility in a high-end war aside from stand-off cruise missile platforms.

      As far as nuclear assets, bombers are the most versatile component of the triad for both delivery and signalling for deterrence. In a nuclear war against smaller states such as Iran or North Korea, the deployment of only nuclear armed bombers would reduce the risk of China or Russia misinterpreting US actions when compared to ICBMS and SLBMS.

  2. You have got it exactly backwards on the J-20/J-31. The J-20 is 'shielded' for much the same reason as the M-50 Bounder, the MiG-1.44 and Su-47 and so many other programs where the /perception/ of capability turned out to be not the intention of it's execution.

    The J-20 is absurdly clunky, slab sided, enormously oversized (wetted area) for the thrust and without any real thought given to either what a persistent supercruise platform or a penetrating stealthy one might look like.

    Some thoughts: You don't achieve 1,200nm at Mach 1.35. You do it at Mach 2.5. At that speed, the nm covered per thousand pounds of fuel burned becomes workably but ONLY if you reduce drag as much as possible. A large, aft mounted, delta wing can help you get there as far as lift distribution and ruling/profile drag, but a forward mounted canard spoils all of this because it changes the shock distribution from the nose and implies a low enough CG rnage that you have to pull the nose up instead of pushing the tail down to avoid Mach tuck.

    Canards also drastically effect forward quarter stealth with multiple return aspects between wing and foreplane axes and secondary surface break and actuator penalties. Canards imply a need for large upforce displacement during low speed maneuver inherent to putting a huge amount of weight in the weapons bay volume, ahead of the wings yet the amount of trim effect it can have without breaking the back of the jet at high transonic and supersonic speeds is so minimal as to essentially require locking it in place because of the ENORMOUS Q effects inherent to deflecting that much fluid stream over the wing roots.

    You can and indeed must strengthen a jet where the control effectors impart bending moments to the center bodies which is why the stabs and the vectoring nozzles on the F-22 are in the same axes as the wing TEF. But you cannot afford to add weight both in front of and behind the jet's CG as structural stiffening which means that the canards are never going to be joined by thrust vectoring nozzles as a mixed effector system. Which means that you are now maneuvering, at supersonic speed, solely on downforce from the wing TEF surfaces and that is hardly likely to make the J-20 hyper agile as claimed.

    Look at the AL-31s or TS-117s or whatever they are 'new AL-41' being called. They are huge.

    Waaaaay to long for the thrust class, indicating low pressure ratio rise between compressor stages. Compare this to the F119 which looks vastly bigger than it actually is, simply because, if you remove the TVC nozzle, it is _very short_. Almost F414 short. It is fat but you can deal with fat by scaling the jet. What you cannot do is put a 12-15ft long weapons bay ahead of two TF30 sized Flanker engines and not expect to have an unwieldy and hard to fineness taper body without resultant adverse effects on fineness ratio, profile drag and boat tail effects.

    1. Area rule in particular works on a smooth transition between airfoil and fuselage apparent widths and cannot accommodate a straight, slab sided, fuselage box which has no taper or waisting effect. This is simplistic Aeros 101 stuff which has been known since the F-102. But it is not done here because Russian aero materials capabilities don't allow for short engines to nestle tightly up against weapons bays.

      The forebody and nose are equally enormous, vastly beyond what is needed to enclose a no-gimbal AESA and the resulting effects upon the inlets, even with the DSI, is a gaping 400-500lbs/sec opening which would be fine if the WS-10 engine was in the 50-70,000lbf thrust range but not if it is a 30,000lbf powerplant. A jet gets upwards of 50% of it's (compression) thrust through the inlet but the almost 70% of it's drag as well.

      The canopy is primitive and poorly blended for RCS reasons with limited view aft, over the enormous spine. The side missile bays are foolish because they highlight the idiotic notion of getting a 50-70,000lb airframe into a 9G turning fight with a potentially 20-30,000lb airframe and thinking you will win. Yet they don't allow for a much longer PL-12 or PL-15 which might have the motor impulse to engage in true (JDRADM like) HOBs performance. Something to consider when you look at the enormous length of fuselage required for the Canards and the idea that a bomber cannot afford to mix payloads in it's main bays, for want of wingspan carriage box and hardpoint CG/rating limits.

      Everything that the J-20 got wrong by trying to be an ATF drawing from the 1980s, the J-31 essentially gets /right/ except for scaling.

      Basically, you cannot create a stealth fighter in an F/A-18 class airframe size and weight volume. Stealth creates such an enormous weight penalty that it takes a rather enormous wing (500-600 square feet) to offset it and this in turn dictates things like fuselage lengths for chord and sweep and resultant drag effects as thrust and fuel requirements.

      What is wrong with the J-31 is that it is attempting to be a 62ftX44ft Raptor in a 55ftX37ft Hornet while powered by 19,000lbf GE F404-GE-402 class RD-93 instead of (at least) 22,000lbf F414 if not 25,000lbf EPE equivalents.

      Bluntly, the J-20 is what results when you take a total package concept you don't understand the operative particulars for and assign an in-house government team with unlimited resources to 'better it!'

      The J-31 is what happens when you tell a smaller, commercial, enterprise to 'match it!'. Shenyang built a nice little sports car which is just slightly porky for it's engines because CAIV was too strenuously applied.

      Retire the J-20 without comment, shift funding to a scaled up J-31 with proper integration of things like TVC boosted agility and much bigger fuel/thrust trusts and you will find that the PLAAF will bow towards the superior design -for their needs- (the J-7 is a point defense interceptor, the J-10 is a more expensive point defense interceptor, the J-11/16 are OCA and strike optimized platforms, there is nothing which can enable their penetration with selective IADS and ISR kills). China is a big place, it is cheaper to have multiple airbases and a shiftable force construct of high end, long range, capable fighters than it is to fight wars of capacity and attrition with low end garbage.

      The J-20, despite it's size, is low end garbage in much the same vein as the J-8 before it.