China's J-20 stealth jet isn't 'a dominating aircraft,' but it doesn't need to be for what China's military has planned

• China's air force continues to improve and expand its fleet of J-20 stealth fighter jets.
• The J-20 is China's first stealth jet and a growing part of an already sizable aviation force.

Twelve years after the J-20 was unveiled and six and half years since it entered service, the Chinese military continues to improve its first stealth fighter jet, adding more advanced features as it expands the fleet and the rest of its already sizable aviation force.

China's air force and navy now make up the largest aviation force in the region and the third largest in the world. They have a total of 1,900 fighter jets, including J-20s that have been "operationally fielded" by China's air force, according to the US Defense Department.

Chinese officials have said the J-20 is being used by all five of their military's theater commands, including to intercept US jets over the East China Sea, but it is still not "a dominant aircraft" compared to the US's F-22 and F-35 stealth jets, according to US Air Force officials who track China's air force closely.

Like China's other hardware, however, US officials say the J-20 is suited for what Beijing considers its near-term needs — keeping the US military from intervening in a war in the Western Pacific, especially around Taiwan.

'High-quality results'

Assessments of serial numbers on J-20 aircraft at public events in 2022 and 2023 suggest that more than 200 J-20s have been built, surpassing the 187 F-22s the US built between 1996 and 2011 and doing so sooner than expected.

The Chinese air force is developing the J-20 fleet as it grows and "is preparing upgrades" for the jet, according to the Pentagon's most recent report on the Chinese military, which covers developments through the end of 2022.

Those upgrades may include increasing how many air-to-air missiles the jet can carry in its low-observable configuration, installing thrust-vectoring engine nozzles that would allow for tighter, sharper turns, and installing domestically developed WS-15 engines that would enable the jet to super-cruise, or to fly at supersonic speeds without using its afterburner.

Chinese designers intended to outfit the J-20 with WS-15s from the outset, but China's aviation industry has struggled to produce advanced jet engines. Older engines have been used as placeholders, but imagery that emerged this summer showed WS-15 engines on a prototype of a new variant of the J-20.

"We've seen the long, hard work that has gone into the bane of what had been their existence, aero-engines," Brendan Mulvaney, director of the China Aerospace Studies Institute, which is part of the Department of the US Air Force, said at a conference in mid-July, shortly after the imagery appeared on social media.

Chinese-made jet engines "are not nearly" at the level of US-built engines, Mulvaney added, "but they've spent a decade focused on trying to make aero-engines, because that was really what was holding back" China's air force.

"That's now yielding pretty high-quality results, which they're putting into their newest aircraft," Mulvaney added.

Along with the ability to super-cruise, the WS-15 engine is expected to improve the jet's electrical-power generation and its thermal-management properties and allow for future development — important features because the new prototype "is an example of a significantly enhanced J-20 variant that will feature major upgrades to subsystems and materials as well as displaying external changes," Rick Joe, an analyst focused on China's military, wrote this summer.

Despite the improvement and expansion of the fleet, the top US Air Force officer in the Pacific is still skeptical of the J-20's ability to match up with US fifth-generation jets.

Gen. Kenneth Wilsbach, the head of US Pacific Air Forces, said in September 2022 that his command had had "a limited opportunity to assess" the J-20 but that it was not something to "worry too much about." Asked about the jet again this year, Wilsbach said China had done well replicating US technology but had yet to develop the training and relationships that bolster the effectiveness of the US's fifth-generation jets.

"They've done some good work with copying the US, frankly, because pretty much most of the technology in that airplane is stolen from the US," Wilsbach said at the Air and Space Forces Association conference in September.

"I don't think that it's a dominating aircraft at this point compared to what we have, and what I would tell you is if you compare just aircraft-for-aircraft and you take the training that our people get and throw in interoperability with allies and partners, the Chinese probably still are at a pretty big disadvantage," Wilsbach added.

'Chinese solutions to Chinese problems'

China has pledged to develop its armed forces, officially known as the People's Liberation Army or PLA, into a "world class" military by 2049, the 100th anniversary of the founding of the People's Republic of China. Officials have not defined what "world class" means, but advanced hardware, like the J-20, is seen as an important part of it.

Developing and effectively employing advanced jets, warships, and other platforms takes time, however, and China's military ambitions in the near-term have focused on equipment that Mulvaney has described as "good enough" to achieve Beijing's goals — namely, preventing outside intervention in a conflict on China's periphery.

"Remember that, at least for the near future, China plans to play a home game," Mulvaney said in July. "They plan to have a measure of sanctuary within the Chinese mainland, and so they've adapted to field a force with that in mind."

Those adaptations include long-range missiles that can disrupt the aerial-refueling operations on which US aircraft rely to cover vast distances in the Pacific, as well as heavy investment in anti-ship ballistic and cruise missiles and in space-based systems to guide them toward US warships far from China's coasts.

"They don't need to build a J-20 that's as good as the F-35s that we're talking about today," Mulvaney said. "They just need to find a way to prevent those F-35s from intervening in PLA operations, so they've built air-to-air missiles that will outfly ours."

"We never would have thought about throwing a ballistic missile against an aircraft carrier because that's just not a problem we had," Mulvaney said, but China plans to use those missiles "to push the aircraft carriers back so the Navy F-35s can't get there."

Those efforts are meant to enable China's air force to operate "in and around China," including over the roughly 100 miles separating the mainland from Taiwan — a proximity that explains why China's air force "has yet to build a full tanker fleet of any size or substance," Mulvaney said, describing the PLA's approach as "Chinese solutions to Chinese problems."

For its part, the US Air Force is adapting to what it expects to face from China in a war in the Pacific. It is developing a concept for more dispersed basing, adding more capabilities to its cargo planes, investing in more efficient tankers and in drones that will soak up Chinese missiles, and building new, longer-range missiles of its own.

Many of the US Air Force's new platforms and concepts will take time to produce and to mature, however. Where officials say the US still has a clear advantage now is in its pilots.

"I wouldn't think that any of them have prowess like an American fighter pilot. They are not in the same category as what we train to," Wilsbach said of Chinese fighter pilots. "That being said, they are improving. They've improved a lot over the last decade."

China's military has emphasized improving its combat readiness, which entails not only more training "but making its training more rigorous and realistic" and addressing training and education issues related to conducting complex operations across its service branches, according to the Pentagon report.

"China writ large is trying their best to improve themselves by improving their training scenarios" and gleaning insights from former Western pilots, Wilsbach said. "They're reaching out to try to improve themselves, and so they are getting better. They're not on the same level as US or other Western pilots, in my view."