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Hello everyone, this is a partial translation of an episode from the Chinese-language military podcast "察话会", recorded after a US F-35 was damaged by Iranian air defences in April. Its hosts, Shilao, Yankee, and Ayi, discussed China's history of developing both stealth and anti-stealth technologies and theories. While most of the information here is already known to many, I found some of the details very interesting, including how the J-20 was shot down by a MANPADS missile during an internal exercise. Hope you guys find it useful.

(Note: All images below are sourced by me from the Internet based on my understanding of the topics at hand. It may not fully represent the opinions of the hosts in the original podcast.)

PLAAF J-20 & transporter erector launcher (TEL)

When it comes to countering enemy aircraft with stealth characteristics, the PLA Air Force has historically regarded this as a top priority. One approach that often came up in discussion is the use of passive infrared electro-optical sensors to identify and track stealth targets. However, many factors, such as weather conditions, may negatively impact the electro-optical sensors’ performance. And since the components used in multi-channel infrared systems were considered highly advanced for China at the time, it could manufacture them only at a very high cost, or pay a premium to import from the West through unconventional means.

The electro-optical targeting system (EOTS) on J-20S

As a result, China had demonstrated interest in other solutions, including the Czech VERA-E passive surveillance electronic support measures (ESM) system. Although its real-life performance did not live up to its reputation, it was still good enough for China to consider developing a similar system with an improved backend algorithm and array combination. And as the elusive and long-delayed HQ-8 surface-to-air battery had shown, such a system was sufficient in providing targeting data to guide the missiles. That said, the cost of these ESM surveillance systems remained too high, and their targeting data could only enable missiles to engage aircraft with large signatures and poor maneuverability, such as AEW&C platforms.

Vera-NG passive surveillance system

Nevertheless, the ill-fated HQ-8 validated the feasibility of integrating passive ESM systems in surface-to-air batteries and facilitated the development of China’s expertise in radar technologies, leading to the successful development of the HQ-20, which was first unveiled at the September 2025 Victory Day Parade. Needless to say, the HQ-20 is an air defense system designed specifically to counter stealthy targets, aided by the PLAAF’s experience in operating the J-20 stealth fighters. Prior to the service entry of J-20, designers of ground-based air defense systems merely perceived stealth fighters as jets with lower RCS. As such, these designers would only rely on theoretical equations to calculate the detection range based on the emitting power of friendly radars and the target’s RCS. The intelligence about the F-117’s shootdown incident provided by the Russians did not help much either, as both nations agreed that the former Yugoslav 250th Air Defence Missile Brigade hit the Nighthawk largely by coincidence and that it was very hard to replicate. In other words, to obtain information that is needed to draft HQ-20’s technical brief, a capable fifth-generation fighter like the J-20 would be necessary as a reference point.

HQ-20 air defense system

Regarding the missiles themselves, China had no issues during the development of the HQ-20, since it already had extensive experience with various guidance methods. Therefore, the development team focused on optimizing the missile’s guidance laws and fuze-warhead matching to maximize the probability of kills without increasing warhead size, akin to deliberations by Americans on their SM-3 and PAC-3 MSE interceptors. These optimizations are ever more relevant for HQ-20 compared to other air defense systems, as each HQ-20 launch vehicle contains 8 missiles.

Interceptor launching from HQ-20

Despite the progress PLA has made in developing and fielding new ground-based air-defence systems to counter stealth threats, it is fully aware that its Air Force also needs to play its part. Given the results of air combat exercises involving J-20s, the Air Force has found that the difficulty of joint operations in taking down fifth-generation fighters falls short of its previous expectations in some respects, while exceeding them in others. Specifically, PLAAF discovered that, contrary to earlier beliefs, fifth-generation fighters can be detected by many more types of assets, including AEW&C aircraft, long-endurance airborne equipment, and even large, ultra-long-range fixed radar. These assets can form a so-called “information box”, detecting and tracking stealth aircraft with several types of sensors, and thus form a common operational picture (COP) that improves the chance of detection.

Large phased-array radar (LPAR) station in Jamusi, China

On the other hand, the PLAAF also realized that fifth-generation stealth fighters possess a high degree of situational awareness that exceeds previous expectations, meaning they will not remain in such an “information box” for long. Unlike the F-117 of the 1990s, stealth fighters nowadays will not strike pre-determined targets along pre-determined routes. When J-20 was first officially revealed, it was described as “a needle that penetrates the web”. The stealth fighters will prioritize hitting targets that pose the greatest threat, so that the “information box” has a few holes for them to escape through. Amid a spiraling competition, the J-20 evolved into the J-20S and J-20A, while Army and Navy radar systems have also joined the counter-stealth ecosystem.

Type 346B AESA radar on PLAN Type-055 destroyer

The USAF shares a similar sentiment, in which the very concept of stealth needs constant modification. In the past, radar stealth encompassed only the narrowband, and as long as an aircraft fell below a certain RCS threshold, it could be characterized as low-observable (LO) or very low-observable (VLO). But now, the USAF understands that its air fleet needs to counter more than just the X-, C-, and S-band radars commonly seen in Soviet-era air defense systems. When facing an adversary with highly capable, innovative radar technologies like China, broadband stealth will become an indispensable feature of next-generation stealth aircraft like the NGAD (F-47) and the B-21. In other words, on fighter jets’ engines, traditional measures against X- and S-band radars will no longer be effective.

The engine nozzles of USAF F-22 Raptor

The J-20 was no different, since it was designed to shield itself against specific radar bands commonly used by air-defense systems. As such, when J-20 pilots accidentally enter the enemy’s “information box”, they do not attempt to evade radar bands that are impossible to hide from. Instead, they will disrupt the kill chain by striking X- and S-band radar systems, given the time needed for radars in other bands to generate targeting data. More importantly, when facing a systematized anti-stealth network, J-20 rarely fights alone. In some exercises, there are extreme cases in which J-20s guide Dongfeng-series ballistic missiles to their targets. To some, this seemed like an overreaction to protect the jets from the enemy’s “information box”. But in fact, PLAAF is well aware of the inevitability of tactical aircraft losses in a hot conflict. From its perspective, the J-20s’ mission is to put themselves in a vulnerable position while penetrating detection zones where the enemy holds an advantage. By doing so, they may expose themselves to dangers, but it would also enable them to deal decisive blows against high-value targets.  

DF-17 intermediate-range ballistic missile

That being said, when PLA itself faces stealth threats, it had once experienced a unique stage in which the development and application of anti-stealth capabilities carried political weight, akin to the fallout from the F-117 shootdown during the Kosovo War. From its perspective, no matter how many high-value assets and ground-based air defense systems were destroyed, even if a single stealth aircraft like the Nighthawk was shot down, the immense cost was worth taking. But nowadays, the PLA understands that anti-stealth capabilities should instead be part of a toolset that dismantles the enemy air force’s systematic structure, and that any victories should take into account friendly losses. After all, stealth aircraft like the F-35, F-22, and B-2 always operate alongside their support networks, including KC-135 and E/A-18G Growlers, which conduct in-air refueling and SEAD operations. Conversely, the behavior of these support assets may also reveal the presence of stealth aircraft on a grander scale.

USAF F-35A & KC-135 aerial refueling tanker

The fact that stealth fighters are not invincible when fighting alone is also evident in the PLA’s internal exercises. Specifically, there are reports of a J-20 being shot down when it was egressing through the exercise area’s boundary. On a certain hill, there was an enemy Man-Portable Air Defense System (MANPADS) post purely by coincidence, and the unlucky J-20 was thus knocked out of the sky by the shoulder-mounted FN-6. It indeed reflected how this particular J-20 unit underestimated its enemy, since the downed aircraft’s flight path lay at the edge of the MANPADS’ flight envelope. Also, at the planning stage, the intelligence this unit received indicated that the enemy air defense unit’s primary interceptors would enter a blind spot if the J-20s flew in the valley.

FN-6 MANPADS

In fact, the MANPADS detachment in this exercise had never expected to take down a hefty prey like a J-20 stealth fighter. According to an interview afterwards, those in the detachment believed they could only hit a Su-30 or a JH-7 fighter-bomber if they were lucky. On the other hand, during the debrief, the pilot of that J-20 was not very happy with the judgment that his jet was shot down. He argued there was only a simulated lock, and in real combat, he could simply release the flare, engage the afterburner, and evade the MANPADS missile with ease. In return, his commander criticized such an attitude and commented:

PLA soldiers practicing aiming FN-6

Look, what you are piloting is a very capable J-20, and what you faced were two young volunteer soldiers with less than 7 years of service combined. Do you have any idea about how much money our nation has spent on training them versus training you? What else would you want to say? The flare and extra jet fuel you want to spend will cost more than that FN-6 missile! Even without considering the economic part, if you put yourself in the situation where J-20 has to deplete the energy of an incoming MANPADS missile in a struggle, then, on a grand scheme of things, you are already lost.  

PLAAF J-20 releasing flares

Putting aside these harsh criticisms, J-20s being shot down during exercises is not uncommon. And ever since J-16s from the 40th Air Brigade successfully downed a J-20 for the first time almost a decade ago, pilots and others alike have done their best to identify which of those losses are caused by avoidable negligence. By contrast, the rest are considered necessary losses that expose the enemy’s positions, thereby achieving the air campaign’s objectives. In other words, unlike in the past, PLAAF no longer views combat losses of stealth aircraft as a “political burden” needed to be avoided at all costs. That said, during peacetime, victories in WVR dogfights without firing a shot, such as a J-16’s successful intercept of two F-22s in the East China Sea, can still be endorsed as a political victory, even though details of such intercepts would diverge greatly compared to anti-stealth technologies and tactics used in real engagements.

PLAAF J-20, J-16, & YY-20A aerial refueling tanker

But on the matter of large, strategic aircraft like the B-2 stealth bombers, the downing of even one of them in future conflicts would have significant political implications for the PLA, thanks to such aircraft’s bombing of Chinese embassy in Belgrade in 1999. In addition, during the 2000s, there were persistent rumors on Chinese military forums about the B-2’s incursion into Chinese airspace above Shanghai, other coastal cities, and even Beijing. Therefore, from the public to the military, the B-2s seem to be a type of aircraft at great odds with national pride, and taking them down would be a trophy everyone desires. As a result, the PLA has devised many approaches, the most promising of which is to strike their base southwest in Diego Garcia with DF-26 ballistic missiles, also known as the Guam Killer. And speaking of Anderson Air Base in Guam, it is also a forward operating base for B-2 stealth bombers, so it is on the prioritized target list as well.

DF-26D intermediate-range ballistic missile

Even when B-2 bombers are airborne, the PLA has greater confidence in shooting them down than before, due to the intelligence it has gathered on other flying-wing aircraft, such as the RQ-180. Nevertheless, a few questions remain, including the level of damage B-2 stealth bombers can sustain when hit in the air, given that they have more complex control surfaces and yet also have four engines housed within the fuselage, which increases their resilience. Therefore, striking them on the ground is still the preferred option, with the added benefit of them being wide and easy to target. When it comes to the newer B-21 bombers expected to be fielded in larger numbers, they are more likely to surprise the Chinese with attacks because such bombers can operate from more bases and, in theory, rely less on supporting assets like aerial refueling tankers. But despite numerous advantages the B-21 holds over its predecessor, given such a bomber’s relatively large size, China’s advanced counter-radar stealth systems and its operating experience with J-20, J-35, and other stealth drones are still sufficient for the PLA to detect the Raider in a timely manner.           

RQ-180 reconnaissance drone

With regard to the next frontier in aerial warfare, collaborative combat aircraft (CCA) drones, China determined that they will have even lower RCS than manned stealth fighters due to their smaller size, while also being more attritable, so they can better act as the point man in an air formation. But as of now, CCA’s effective deployment hinges heavily on the situational awareness provided by a system of other assets. Fortunately, China has already built such extensive networks around its main theatres of operation. Thus, Chinese CCAs, with a smaller, stealthier profile than J-10 fighters, can serve as force multipliers thanks to their very low radar signature and integration with existing support networks. By contrast, no matter how well a manned stealth fighter is designed, it would be very hard to apply radar-absorbent measures to the cockpit canopy, ejection seat, and pilot itself, which are not present on CCAs.

Two types of Chinese CCAs

Furthermore, one must be aware that, given the USAF pilots’ average annual flying hours have been declining for some time, it would be impractical for them to maintain proficiency in every single subject, especially in dogfighting skills. Therefore, if Chinese CCAs, with superior stealth characteristics, close their distances and engage in WVR dogfights with American fighters, how can these pilots effectively respond to such a threat? According to personnel working on China’s CCA projects, their creations, despite being loaded with imperfect software iterations, have already defeated several pilots who once won the PLAAF’s “Golden Helmet” air combat competitions. Such drones, with very low radar and visual signatures, gave those pilots the impression that they were evading ground-to-air missiles with infinite energy. And unlike the drones made by Anduril Industries, Chinese CCAs already feature internal weapon bays (IWBs).

Two types of Chinese unmanned air-dominance fighters

To counter non-emitting targets like CCA drones, the PLA has also doubled down on efforts to develop better electro-optical sensors so these drones can be detected earlier, and thus enlarging the anti-stealth “information box”, alongside fundamental upgrades in radar technologies. In summary, the PLA’s understanding of stealth is that, while investing in relevant technologies is critical, stealth aircraft are not the ultimate “killer weapons” that can guarantee victories, nor is any single type of anti-stealth capability. Only by accepting that stealth fighters are attritable and integrating them into larger, systematized warfare networks can they achieve their maximum potential.   

PLAAF J-20 & KJ-500