By Rick Joe
Service Status
The J-20 was announced to have entered service by the PLAAF in late 2016, and then subsequently to have “been commissioned with combat troops” in February 2018. These announcements likely referred to the J-20 being activated in the Flight Test and Training Base in Dingxin and the Flight Training Base in Cangzhou, respectively.
These two units are sometimes referred to as 176th brigade and 172nd brigade respectively, but are more often referred to as simply “Dingxin” and “Cangzhou.” The unit in Dingxin has the role of developing and testing tactics, while Cangzhou serves the role of advanced training and as a combat reserve unit. Therefore, J-20s officially “entered PLAAF service” when Dingxin activated J-20s around late 2016, while J-20s entered service with “combat troops” in February 2018 when Cangzhou received their J-20s.
A J-20 with serial number 62001, indicative of service in an active combat unit at 9th brigade, Wuhu. Source: PLA Air Force WeChat Account
Rumors from late 2018 to early 2019 suggested the first regular frontline PLAAF unit to receive J-20s would be the 9th brigade located in Wuhu, under the Eastern Theater Command. A few video clips and pictures taken in early 2019 from the area suggested J-20s had indeed begun arriving at Wuhu, and satellite pictures taken of the 9th brigade in April demonstrated at least three J-20s were present at the unit. However, the picture released from the PLA of a J-20 with serial 62001 was the first clear evidence of a J-20 belonging to 9th brigade, fully confirming J-20’s status in a combat unit after almost a year of snowballing rumors, pictures and videos.
While this is a significant milestone, the exact current strength of J-20s in PLAAF service is not known, let alone the total number of production J-20s that have been constructed.
How many J-20s are there anyway?
Estimating the number of fighters in PLA service is difficult for most types, let alone one as new and significant as the J-20. Estimates are usually made by two major options:
Option one: observing factory serial numbers from pictures taken of new airframes fresh from the production line.
Option two: counting and extrapolating the number of confirmed in service serial numbers of an aircraft type.
Option one relies on having photographers on the ground located near a given aircraft factory who are not only willing to take pictures of aircraft and the factory but also willing to post pictures on the internet. Option one also relies on newly produced aircraft having obvious factory serial numbers applied to them, which is not a given. In the case of the J-20, the last three to four years has seen a significant drop of semi-regular, up to date pictures of the Chengdu Aircraft Corporation (CAC) compared to when the J-20 was in development between 2011 and 2016, where up to date pictures of new J-20 prototypes were relatively common. Since mid to late 2016, photos of CAC’s factory have been few and far between, and the pictures that are released often lack clear time indicators, making it near impossible to grasp the J-20’s production rate or pattern. This is further hindered by the lack of obvious production serials on the few J-20 pictures that are released.
Option two is similarly dependent on the release of photos of the J-20 in service bearing visible serial numbers. Such pictures can be revealed from official PLA sources (as in the case of 62001 from the 9th brigade), or it can be from photographers on the ground. However it is also common for enthusiast photographers to deliberately obscure serial numbers to avoid releasing potentially sensitive military information. The problem with option two is that airframes with visible serial numbers often may not represent the full strength of a unit’s aircraft. The 9th brigade is an excellent example — satellite pictures strongly suggest at least three J-20s were present as of April 2019, meaning the recent release of s/n 62001 almost certainly is only a small fraction of the actual strength in Wuhu.
Option two is useful for providing a “minimum floor” of confirmed J-20 airframes, with 13 unique serial numbers (including 62001) identified as of August 2019, distributed between Dingxin, Cangzhou, and Wuhu. However the actual number of J-20s in service and produced is likely to be much greater and the PLAAF is sensibly taking measures to avoid disclosing what the actual up to date quantity is.
J-20s engines
Some erroneous reporting by certain media outlets has suggested that production J-20s in previous years were powered by WS-10 engines and that the J-20 has been preparing to receive WS-15 engines. This information is untrue, as current production and in service J-20s have been powered by variants of Russian Al-31 engines. The J-20 has been test flown with WS-10 engines; however the J-20 has not been test flown with WS-15 engines and the WS-15 is certainly not “approaching mass production.”
In late July 2019, some rather credible rumors and blurry pictures from CAC’s factory strongly indicated that production J-20s have been equipped with WS-10 variant engines, replacing the Russian Al-31s. However, it will likely take a number of months if not years for clear pictures of WS-10 powered J-20s in PLAAF colors to be released. It is also noteworthy that those same rumors and pictures strongly suggested J-10C production has shifted to WS-10 engines as well.
Some of the aforementioned erroneous media outlets had also suggested that J-20s has yet to be mass produced due to bottlenecks with the WS-15 engine. This is difficult to substantiate at best, and untrue at worst. For one, the J-20 only began production in late 2015, and initial production rates for any new aircraft type tend to begin relatively low before climbing upwards in subsequent years.
The most up to date rumors suggest the WS-15 might have been fitted aboard a fighter aircraft for testing; however the aircraft is not the J-20 and is likely to be a J-11B or other Flanker aircraft instead. Therefore, it is important to state that the WS-15 will likely only be ready to equip the J-20 by the mid 2020s. Until that time, J-20s powered by interim engines like the Al-31 or WS-10 will still be vastly more capable than any previous PLAAF fighters. Therefore it would be a foregone conclusion that the PLAAF would seek mass produced J-20s as soon as possible irrespective of the WS-15’s immediate availability.
J-20’s weapons suite
The J-20 is currently confirmed to be integrated with two weapon types; the PL-15 beyond visual range air-to-air missile (BVRAAM), and the PL-10 short range air-to-air missile (SRAAM). The J-20 carries four PL-15s in its main ventral weapons bay and two PL-10s, one each in a side weapons bay. Exact capabilities are of course not known for either weapon type, but long-term rumors about the PL-15 have suggested it is equipped with an actively electronically scanned array (AESA) seeker, satellite enabled inertial guidance, and a dual pulse motor capable of combat ranges approaching 200 kilometers. The PL-10 is equipped with a gimbaled imaging infrared seeker and thrust vectoring, giving the missile high off boresight targeting capability, and J-20 pilots have been observed flying with a helmet mount display that should allow the aircraft to exploit that capability. The exact range of the PL-10 is not known; the export PL-10E is described with a range of 20 kilometers but may represent an export graded capability.
The PL-15 and PL-10 also equip various other fighter types including the J-16 and J-10C, and the two missiles are best thought of as analogues to the U.S. AIM-120D and AIM-9X. However, the J-20 currently is “only” capable of carrying four PL-15s in its main weapons bay whereas the F-22 carries six AIM-120Ds. It is strongly indicated that another new BVRAAM is in development (sometimes dubbed “PL-20”) with a smaller form factor to enable carriage of six BVRAAMs. The exact capabilities of this new BVRAAM are not known, but it is important to consider that the current PL-15 was developed on the basis of China’s aerospace industry as of the late 2000s, and “PL-20” will likely enjoy the fruits of advancement made since that time.
There are strong indications that additional air-to-ground weapons are in development for use on the J-20 (as well as the future carrier based 5th generation fighter). This includes an anti radiation missile based on the PL-15, which the J-20 should be capable of carrying four of. A small form factor cruise missile may also be in development – similar in concept to the Joint Strike Missile designed for F-35 and the Kh-59MK2 designed for Su-57 – to allow the J-20 to carry four in its ventral weapons bay. Given the J-20’s primary mission is that of a general air superiority fighter, it is logical that development of specialized air-to-ground weapons for the J-20’s weapons bay were less prioritized than its air-to-air weapons suite.
Sensors and avionics
Superficial information of the J-20’s sensor suite has been widely available for a number of years now. The J-20 is known (or at least very strongly suggested, bordering on confirmed) to be equipped with an AESA fire control radar, and a chin mounted electro optic sensor is also visually present, and six electro-optic apertures are oriented around the aircraft likely forming a passive detection system. It is very likely that the aircraft is equipped with a new generation datalink and electronic support measures and electronic warfare suite that is standard fit for other 5th generation fighters in the world.
But needless to say, we lack clear confirmation of the exact presence of most of these sensors and avionics, and gauging their capabilities and degree of data fusion is impossible. Considering no clear picture of the J-20’s cockpit has even been released, it is rather reasonable to appreciate that the J-20’s sensor and avionics suite enjoys a high degree of secrecy.
Into the 2020s
Going into the 2020s, J-20 production using interim engines (whether it be Al-31 variants or WS-10 variants as recently hinted) will likely be further expanded. The WS-15 is may be ready by the mid 2020s, at which point J-20 production will likely shift to using that powerplant. It is likely that a WS-15 powered J-20 may receive a new variant designation entirely (such as J-20B), but it is not known if such an aircraft will undergo any significant physical redesigns. It is also not known whether other physically different variants of the J-20 (such as a tandem seat variant) may be produced, despite some unsubstantiated rumors over the years.
The 2020s will also raise the question of just how many J-20s the PLA will eventually seek to acquire. Currently it is strongly indicated that the PLA Navy’s 5th generation carrier fighter will be derived from the FC-31, but it is not known if a future land based variant may also be produced to provide a medium weight 5th generation complement to the J-20. Therefore, the exact composition of the PLA’s overall 5th generation fighter fleet into the late 2020s cannot be predicted.
That said, given the projected numbers of F-35s that will enter service with the United States and various nations in the western Pacific region, it is likely that the PLA recognizes the need to keep up with its own 5th generation fleet. The J-20 will remain the only in production 5th generation fighter for the PLA going into the mid 2020s at least (whereby a carrier variant FC-31 might finish development and begin production), and it currently seems unlikely the PLA will cease J-20 production before the early 2030s.
During the late Cold War the U.S. Air Force originally planned to procure 750 Advanced Tactical Fighters (the program that gave birth to the F-22); however, post-Cold War threat assessments as well as the development of the F-35 gradually reduced 750 to the 187 F-22s ultimately produced for service. It is difficult to envision the PLA would be content with only about 200 J-20s given the threat profile they will face into the late 2020s and early 2030s. But it is also rather early to seriously suggest what kind of production run the J-20 may ultimately enjoy going into that time period, not least due to the difficulty of predicting what future geopolitical and economic trajectories China and the region may undergo in the intervening period. Therefore, it is very difficult to predict the final production run of J-20s at this stage despite what we know about the PLA’s likely 5th generation requirements going forwards.