China's new J-20 is nothing 'to lose a lot of sleep over,' but the US's stealth advantage isn't safe, US commanders say

• China's air force has rapidly grown in size and capability, adding advanced jets like the J-20.
• The J-20 isn't "anything to lose a lot of sleep over," the head of US Pacific Air Forces said this week.

The rapid expansion of China's fighter fleet has alarmed its rivals, but its most advanced jet, the J-20, isn't too much of a concern, the top US Air Force officer in the Pacific said this week.

"It's their most modern aircraft. We've had a limited opportunity to assess it. It seems OK," Gen. Kenneth Wilsbach, the head of Pacific Air Forces, said Monday at the Air, Space, and Cyber Conference in National Harbor, Maryland.

The J-20 was introduced in 2017 and is China's first fifth-generation fighter. Like other Chinese military aircraft, it faces technological challenges, most notably underpowered engines.

Beijing, however, continues to develop the jet, making plans to add a better engine and sending it on longer-range operations.

"It's not anything to lose a lot of sleep over, but they seem to be a building a lot of them, and certainly, we're watching them closely and seeing how they develop and how they operate them," Wilsbach told reporters.

The J-20 and the FC-31, a fifth-generation fighter that is in development and will likely be carrier-based, will augment the Chinese air force's fourth-generation fleet and "bolster its air-to-air capability," the US Defense Department said in its most recent report on the Chinese military.

The two aircraft "feature high maneuverability, stealth characteristics, and an internal weapons bay, as well as advanced avionics and sensors providing enhanced situational awareness, advanced radar tracking and targeting capabilities, and integrated [electronic warfare] systems," the report added.

A top official with the state-owned firm developing the J-20 said in April that the jet was conducting regular patrols over the East and South China Seas, including combat patrols requiring a higher level of readiness.

PLA Daily, an official military newspaper, said in August that J-20s had repeatedly scrambled in response to foreign aircraft entering China's East China Sea air defense identification zone.

Wilsbach said in March that it was too early to tell whether China would use the J-20 as a multirole fighter or focus on air superiority.

But Chinese pilots appear to handle the J-20 "pretty well" and US pilots were "relatively impressed" with Chinese command and control of the jet during an encounter over the East China Sea, Wilsbach said at the time.

"We learned a lot from that engagement," Wilsbach said Monday. "It's nothing that I would, frankly, worry too much about."

Asked about the J-20 on Tuesday, Gen. Charles Brown Jr., the Air Force chief of staff and Wilsbach's predecessor at Pacific Air Forces, echoed Wilsbach but said the Chinese air force's advances are worth watching.

"It's not something to lose a lot of sleep over, but I'm going to pay attention to it," Brown said of the J-20. "We can take a look at it today and say we're not going to lose a lot of sleep. I'll lose sleep if we don't continue to modernize our Air Force to ensure that we stay ahead of where they are."

China's air force is believed to have several dozen J-20s — the Pentagon says it has "operationally fielded limited numbers" of the jet — fewer than the US Air Force's 186 F-22s or its roughly 300 F-35As.

The Air Force continues to struggle with some elements of the F-35 program, including a new set of upgrades for its software and weapons.

It also wants to begin divesting its oldest F-22s to save money that it can put toward development of a sixth-generation fighter, a program known as Next Generation Air Dominance.

"When I think about the fifth-gen capability of the adversary as an air force, I also think about it as we go down the path of Next Generation Air Dominance," Brown told reporters Tuesday. "We want to make sure we maintain our advantage, and that's the aspect I'm trying to focus on as the service chief, to ensure we continue to modernize and bring on that capability so we don't lose sleep."

Sixth-generation aircraft are still largely conceptual. They aren't expected to arrive until at least 2030, and little is known about the capabilities they will have.

A top Chinese aircraft designer said in 2019 that "pre-research" on a sixth-generation jet had begun, and there's no debate there about those jets' relevance, Gen. Mike Kelly said at the conference on Wednesday.

Kelly, who oversees training of US fighter pilots as head of Air Combat Command, has described China's development of fifth- and sixth-generation jets as a "growing threat."

Kelly told reporters that Chinese designers have taken an iterative approach that has allowed them to bridge the technological gaps between generations of aircraft, evolving from a reliance on older Russian-designed Sukhoi jets to more advanced foreign and domestically developed models.

"That's how they did their fourth-gen. They started with Su-27, morph into Su-30, [built] their own J-16," and, in 2016, acquired the Su-35, Kelly said. "They build that technology base to where, essentially, that's a good airplane, Su-35 — fourth-gen airplane, fifth-gen avionics, fifth-gen speed."

That approach "makes it a little bit easier for them," Kelly said, adding that he expects more advances. "I essentially cyberstalked the folks that do the design over there," Kelly said, "and they're not done, not at all. They know what they're doing."

Despite China's technological advances, its troops are still considered untested by combat and lacking the kind of experience and autonomy that Wilsbach said sets US pilots apart.

"Our forces are really well trained. They're very well equipped, and the thing that I think I'm very happy with, and in fact comfortable with, is our airmen's ability to lead at the absolute lowest levels," Wilsbach told reporters on Monday.

"I'm comfortable sending an F-22 or an F-35 pilot out there that might be a lieutenant. They know how to do it," Wilsbach added. "I actually go fly with them, so I have firsthand knowledge."