China has a heavy fighter force, and it is getting heavier. The bulk of Chinese fighter acquisition funding is pouring into production lines for large, long-range aircraft that suit western Pacific distances.

But the air force and naval aviation branch fighter fleets are badly fragmented, and no fewer than five major designs are currently in production for them. They are the Avic Chengdu J-10C and J-20A and the Avic Shenyang J-11, J-15 and J-16; the first two are fully indigenous, and the others are developments of the Sukhoi Su-27 Flanker.

• Of five production designs, only the J-10C is medium-weight
• Most production fighters have advanced radar

Evidence points to upcoming advances in the form of new J-10 and J-20 versions and, for the navy, an operational development of the Shenyang FC-31 fighter demonstrator. Although China is a great enthusiast for the long-legged Flanker, there is little sign of it working on future versions—yet the possibility of their appearance cannot be ruled out.

Introduction of new fighter designs will hardly help maintenance and logistics organizations, even as they are relieved of the burden of supporting obsolete Chengdu J-7s and Shenyang J-8s, perhaps around 2026.

China’s bias toward heavy fighters shows up in the balance of designs it has in production, the balance of output numbers and, most decisively, the evident balance of funding.

Of five production designs, only one, the J-10C, is not a heavyweight.

As for output, China built 84 fighters in 2021, about the same as the average of the previous six years, according to new estimates by the Aviation Week Intelligence Network (see chart). Of these, only 24 were J-10s.

And J-10s, medium-weight fighters only about 10% bigger than Lockheed Martin F-16s, should not be expensive. If aircraft empty weight is taken as an index of unit cost, China applied only 18% of fighter production funding to the J-10 program in 2021—and that is probably an overestimate, since the stealthy J-20 is likely to be disproportionately expensive for its size.

The rest of the money is going to heavyweights. These already form 55% of the combined air force and navy fighter fleets. Since big fighters account for more than 70% of current production numbers, the ratio in service will rise, although the FC-31 derivative could be in the medium-weight category.

Apart from J-11s, J-15s and J-16s, the Flanker force includes Su-30s and Su-35s imported from Russia.

An assessment by think tank Air Power Australia gives some idea of the sort of escort capability that Flankers offer China. “The Su-30s are honest 700-nm+-radius-class [1,300 km+] fighters, with plenty of combat gas to burn at shorter radii,” it says.

Such a radius would allow China’s Flankers to operate southeast of Japan, even without aerial refueling, or to maintain long-endurance patrols around Taiwan.

But the various Flanker designs contribute greatly to the Chinese fighter force’s fragmentation problem. The difficulty is not so much the number of types, since the air force and navy operate only five (the J-7, J-8, J-10, Flanker and J-20). Rather, the problem is versions. Maintainers must contend with at least 19 major design variations among the types.

This has resulted in part from China’s rapid advance in fighter technology: Improved versions arrive at short intervals. For example, the J-10A, deliveries of which began in 2003, had a radar with a mechanically scanned array, but the J-10B of 2013 apparently introduced an electronically scanned array, and the J-10C of 2015 has a radar with even more advanced antenna, an active, electronically scanned array (AESA).

Aviation Week’s figures show that if recent production rates are maintained, and if the fighter force does not change in size, the remaining 226 J-7s and 146 J-8s will be replaced in about 4.5 years—mostly by much larger fighters. In the process, the two services will also ditch the seven versions into which those types are divided.

Probably all fighters in production for the Chinese air force now have AESA radars, raising the possibility, but hardly proving, that the avionics are comparable to such foreign designs as the Boeing F/A-18E/F Block II Super Hornet, which entered service in 2005. The J-15 apparently still uses a mechanically scanned array, but the expected FC-31 derivative should replace that shipboard Flanker and will surely have an AESA.

Shenyang used company funding to design the FC-31 (also called the J-31) as a technology demonstrator, but an industry source said in 2018 that the project was then receiving government money to develop it as a naval fighter.

The air force was also interested in it, the source said. However, there has been no confirmation of a version for that service, which obviously rejected it around a decade ago.

The air force presumably thought then that it had enough variation in its fleet already and better things to do with its money and that it could wait for something better than the FC-31 as a successor to the J-10.

That something should be the fighter that Chengdu designer Wang Haifeng has said will be in service by 2035. His timing suggests a prototype should appear this decade. Although it is likely to replace the J-10 in production, the new type need not be in the same weight class.

Meanwhile, the J-20 is very likely being developed as a multirole aircraft as the air force sets aside what was apparently an original plan to limit it to air-to-air missions.

Avic—and specifically J-20 designer Yang Wei—have campaigned for further development of the type for more missions. Since they had to campaign, no such adaptation of the J-20 can have been originally intended.

A long-rumored two-seat version of the J-20 has appeared, perhaps designated the J-20S or J-20AS. (The first operational version is the J-20A; “S” in a Chinese fighter designation stands for “shuang,” meaning “twin,” or twin-seat.)

Although a two-seater is useful as a trainer, the J-20 program has got along so far without one, raising the likelihood that the second crew member in the new version is for strike missions, possibly airborne command and, ultimately, control of loyal-wingmen drones.

If it is to fully preserve its stealth and carry weapons only internally, the J-20 is limited as a strike aircraft. Its main weapon bay is shallow, designed for carrying air-to-air missiles. To preserve a flat underside that is optimal for stealth, the bay doors do not bulge, as do those of the Lockheed Martin F-35 Lightning.

Still, the constricted volume may be acceptable, says Douglas Barrie of the International Institute of Strategic Studies in London, pointing out that improved weapon precision allows for smaller warheads and that a weapon delivered by a stealth aircraft may not need great range. Also, bulging doors could be fitted, at some cost in controlling radar reflections.

A further J-20 upgrade will come when the engine for which it was designed, the WS-15, finally becomes available, perhaps in a few years.

J-20 production is running at 18 aircraft a year, neither fast nor slow by Chinese standards. Aviation Week analysts estimate that 94 J-20As have been delivered.

Another J-10 version, presumably called the J-10D, is probably in the works, since an aircraft of the type has appeared with a thrust-vectoring engine nozzle. The J-10’s production heyday was a decade ago, when it reached 32 units a year.

There is no current indication of another Flanker version, despite reports a few years ago of one called the J-11D. The J-16, a multirole two-seat Flanker, is being built at a rate of 30 a year, including six units of its J-16D electromagnetic-attack subvariant. This is China’s fastest fighter production program.

Shenyang also continues to build J-11s of a two-seat subvariant, the J-11BS, but only slowly. More important, upgrading of the large existing force of J-11s has begun, probably including fitting AESA radars and making the aircraft compatible with new Chinese weapons. The improvements are presumably also incorporated in current production.

The future of China’s Su-30s, all imported, is an interesting question, since replacement by J-16s would offer superior performance, compatibility with new Chinese weapons and lower support costs. This should particularly be a consideration for the navy, which has just 24 Su-30MK2s, which are different to the air force’s 74 Su-30MKKs, another instance of fragmentation.

On the other hand, China has consistently been reluctant to discard fighters. Its retention in the 2020s of J-7s, based on the MiG-21 design of the 1950s, is a notable example of that parsimonious attitude.