HONG KONG: China, particularly the People's Liberation Army Air Force (PLAAF), is extremely proud of its beefy J-20 stealth fighter. Significantly, the aircraft recently celebrated its tenth birthday as a flying machine within the world's third-largest air force, though it remains one of the world's most enigmatic fighters.

Kept under tight secrecy, the Chengdu Aerospace Corporation (CAC) fighter achieved its maiden flight on 11 January 2011, while US Secretary of Defence Robert Gates was in China on an official visit. Taking him by surprise, he later admitted that US intelligence agencies underestimated China's ability to develop a new-generation fighter.

The J-20 formally entered PLAAF service in 2017, the same year the US military began deploying F-35 fighters to Japan. The first combat unit to adopt it from late 2018 or early 2019 was the 9th Air Brigade at Wuhu in the Eastern Theatre Command. This base is some 280km inland from Shanghai, and hosts one of the PLAAF's premier fighter units. The J-20's first deployment to the Eastern Theatre Command emphasizes the strategic priority that the PLA places on Taiwan. This command also counters Japan and the USA.

Prior to that, the J-20 was only deployed in two units dedicated to operational evaluation and tactical training (the 176th Air Brigade at Dingxin Air Base and 172nd Air Brigade at Cangzhou Air Base, respectively).

At least 40 J-20s have been produced so far, but certainly no more than 60-70. It is alleged that CAC set up a fourth J-20 production line in 2019, each line able to produce one fighter per month. At this rate, the J-20 should approach total production numbers of the American F-22 by 2027. This would amount to at least 200 fighters, making it the world's second-most common stealth fighter behind the F-35.

The 20.8m-long J-20 aircraft is intended as an air superiority fighter able to compete with the American-built F-22 or F-35. The J-20 has achieved a credible combat capability, maturing over its ten-year lifespan. It is typical for China to continuously update an interim product with fairly rapid spiral development, and this is true of the J-20.

Indeed, it continues to grow in capability. Its weapon suite will expand beyond the 200km-range PL-15 beyond-visual-range missile and the shorter-range PL-10. It cannot currently carry the 400km-range PL-X very long-range missile that has so far appeared only on the Flanker family and JH-7/A.

A new and smaller beyond-visual-range missile could increase the payload from four missiles to six in the ventral weapon bay. A relatively recent scale model features a right-shoulder protrusion, which could indicate an internal gun will soon be fitted too. Also expected are a small-diameter strike weapon and a cruise missile.

The fighter's sensors should improve as well. However, arguably the greatest enhancement will be WS15 engines, for which the J-20 was specifically designed for maximum manoeuvrability and super cruising (sustained supersonic flight).

Thus, the Pentagon in its 2020 report on China's military stated: "...The PLAAF is preparing upgrades for the J-20, which may include increasing the number of air-to-air missiles the fighter can carry in its low-observable configuration, installing thrust-vectoring engine nozzles, and adding super cruise capability by installing higher-thrust indigenous WS15 engines."

It is believed the Russian AL-31FN engines have not been fitted on the production line since mid-2019, with preference being given to the indigenous WS10 engine, which is also used on the J-10 fighter.

The South China Morning Post published an article in July 2020 claiming an updated J-20B had been unveiled to senior military leaders and that military production was starting. It said the major improvement was the inclusion of thrust vector control, which improves the aircraft's agility. Later, pictures on the internet last October showed the J-20 fitted with WS10C engines with serrated afterburner nozzles.

Production of WS10C-powered J-20s will continue, but even the WS10 is just an interim step. As confirmed by the Pentagon, the ultimate engine destined for the J-20 is the WS15 to help the aircraft achieve its ideal kinematic performance. However, the WS15 failed its final evaluation in 2019, and the coronavirus pandemic is known to have impacted its development too. Developing reliable jet engines has always been a technological thorn in China's side, forcing it to import from Russia in the interim.

Recently, an Aviation Corporation of China (AVIC) computer-generated image showed a twin-seat version of the J-20, underscoring that such a variant will probably appear one day too. If correct, this would be the world's first twin-seat stealth fighter, as Russia and the USA only operate single-seat stealth fighters. Usually, only strike or fighter-bomber aircraft have a two-man crew.

Apart from this aforementioned image, there has been scant evidence of a dual-seat J-20 so far. Nonetheless, it would be suitable for controlling a loyal wingman or drones, and some even contend it could act as a "spotter" for Chinese long-range anti-ship missiles to improve the kill chain. However, the latter would seem to be a task better suited to the DR-8 supersonic stealth drone unveiled in the 2019 Beijing parade.

So how does the J-20 rate compared to its peers from Russia and the USA? Given the cloak of secrecy surrounding this Chinese platform and the absence of any combat, it is an almost impossible question to satisfactorily answer.

Andreas Rupprecht, a German expert on the PLAAF, was asked the same question about the J-20's performance by the online aviation website Hush Kit. He declined to give a direct assessment, but did say: "I'm convinced that the F-22 was actually the benchmark for CAC, but I'm also convinced that it was clear to CAC that developing a twin-engine heavy fighter and a stealth aircraft for the first time after the J-10 would be a huge challenge. All of this is coupled with the knowledge that one has hardly any experience in this area and, above all, that the engines will still only be temporary solutions."

Rupprecht continued, "On the other hand, it has been around 15 years since development of the F-22, and a lot has happened in China in the area of electronics, sensors and materials since then. But it's important to note that the predecessor of the J-20 in PLAAF service is the Flanker and this came from a completely different period, was for a completely different requirement and was designed by a company with vastly more experience. So in conclusion, I'm sure the J-20 is no worse than a J-11B in all areas of performance, but certainly - especially with the current interim engines - it does not come close to an F-22. I do not presume to make any further judgment."

Despite the greater capabilities of the J-20, the type makes up less than several percent of the total PLAAF combat fleet. Most Chinese fighters are still quite dated. The Pentagon's 2020 report stated: "The PLAAF and PLA Navy (PLAN) Aviation continue to field greater numbers of fourth-generation aircraft (now more than 800 of 1,500 total operational fighters, not including trainers) and probably will become a majority fourth-generation force within the next several years."

Of course, the J-20 is not China's only stealth fighter. There also exists the FC-31 that first flew in October 2012. It was rejected by the PLAAF in favour of the J-20, but Shenyang Aircraft Corporation engineers have been busy improving the design; an improved FC-31 variant flew in December 2016 with structural modifications to the canopy, wings and tails. The FC-31 is being marketed to international customers, but none have nibbled the bait yet.

The 2020 Pentagon report noted, "...Development continues on the smaller FC-31/J-31 for export or as a future naval fighter for the PLAN's next class of aircraft carriers." Indeed, this alludes to persistent speculation that the PLAN will adopt the FC-31 as its fifth-generation fighter for use aboard carriers as a replacement for the large and heavy J-15.

The FC-31's airframe is smaller (better for stowage and manoeuvrability aboard a crowded carrier deck or hangar) than the J-20's. It will need reinforced landing gear, folding wings and a tail hook, however. The aircraft could eventually receive WS13E jet engines (in the 9-ton thrust class). These could even be supplanted by the WS19 jet in the 10-11-ton thrust class in the late 2020s. Many ascribe the nomenclature J-35 to such a PLAN carrier-borne design, but this is not official.

In December 2019, the Shenyang Institute said it had begun developing a new type of fighter jointly with the AVIC Manufacturing Technology Institute the year before. Later, a statement by the Chinese Aeronautical Establishment on its WeChat public account - and promptly deleted - promised a new-generation fighter would perform its maiden flight in 2021. Fu Qianshao, a Chinese air defence expert, told the Global Times tabloid this could well be a new carrier-based fighter based on the FC-31.

The PLAN's need for a new carrier-borne fighter is quite urgent, since the incumbent J-15 cannot compete with F-35B or F-35C variants operated by the USA. If a maiden flight were to occur this year, it would likely take another five years for it to enter service; however, this could potentially be shortened slightly given the already long test program of the FC-31.

The second flying FC-31 demonstrator - with serial number '31003' - was transferred to the PLAAF's test flight establishment early last year. That signifies it is now more than just a Shenyang-owned aircraft, and something of direct interest to the PLA.

Addressing the FC-31, Rupprecht explained, "I try to be cautious as possible, since nothing is yet confirmed, but all hints towards the idea that this type has been selected by the PLAN as the J-15's successor and future carrier-borne fighter. Allegedly named 'J-35', a first prototype is said be ready and we expect its unveiling, if not even its maiden flight, early this year."

China has not rested on its laurels with either the J-20 or FC-31, for it is currently developing a sixth-generation fighter as well. Wang Haifeng, chief designer at the Chengdu Aircraft Research and Design Bureau, posits that it will be ready by 2035. This new fighter will incorporate such technologies as artificial intelligence, greater stealth and the ability to control drones, he disclosed in a WeChat interview published in January 2019.

The possibility exists that other features such as lasers, variable-cycle engines, hypersonic weapons and swarm warfare could be added to China's next-generation fighter too. To date, there has been no official pronouncement of such a fighter, but we can be sure that Chinese engineers are already working on this future design.

If this sixth-generation fighter is to be ready for service by 2035, this would suggest a maiden flight at least five years prior to that, and low-rate initial production commencing in approximately 2032-33. Working backwards from this estimated 2035 timeframe, the prototype would then have to emerge by 2028 at the latest to meet the target.

Given that the J-10 appeared 13 years prior to the J-20, this suggests a slightly slower cycle of 17 years between the J-20 and sixth-generation fighter appearing. Even if such a new fighter appears, the J-20 could continue in production.

Instead of merely defending its borders, China is looking at a more proactive approach to defeating enemies beyond its landmass. Fighters like the J-20 and potential J-35 will enable this, and one might eventually see such aircraft asserting themselves in places like the Indian Ocean in the future.

Developing new fighters is hugely expensive, but China has demonstrated political will, martial ambition and heavy investment to make it happen. The J-20 is a mere ten years young and has a long life ahead of it.