High-Quality Shots Of Unpainted Chinese J-20 Stealth Fighter Offer New Capability Insights

The steady flow of intriguing new images of China’s stealthy heavy fighter-interceptor, the J-20, continues over seven years after the jet first appeared. The aircraft is already in operational service with the People’s Liberation Army Air Force (PLAAF) and it continues to evolve and spread its wings, participating in increasingly high-profile joint-exercises and deployments near hotspots along China’s borders. Three new shots help us better understand the build quality of this game-changing machine as well as handicap some aspects of its true capabilities. But above all else, like I have stressed since its first appearance, the photos are a reminder that China’s ability to make great leaps in aerospace materials and manufacturing sciences should not be underestimated. 

The latest images, which recently emerged on Chinese internet, show a J-20 without its gray paint and in its primer coating flying out of Chengdu Aircraft Company’s plant and test airfield. We have seen the J-20 in its yellow undercoatings before, but these images are very detailed in comparison to the vast majority of the shots that have surfaced in the past. Note that the dragon symbols on the nose and tail were added in post-processing and were not actually painted on the aircraft. 

Chinese Internet

The images show the areas where antennas are embedded below the J-20’s skin, as well as where other stealthy composite structures are used to minimize the aircraft’s radar cross-section. The J-20’s large Diverterless Supersonic Inlet (DSI) is shown in great detail as well, including various porous panels that also help separate turbulent boundary layer air from its skin—a process required to feed its engines with stable airflow throughout its flight envelope. 

The jet’s giant maneuvering canard foreplanes are also displayed in grand fashion. These control surfaces help to give the big jet its agility, although they are unlikely to move much when the aircraft is in combat cruise configuration where minimizing its frontal radar signature is critical to its survival. They also work as big air brakes during rollout after touching down. 

A Luneburg lens is also seen attached below the jet to provide an ample radar return. Like American stealth fighters, these bolt-on devices are used to help air traffic controllers see the aircraft during transient flights and for some training operations. In some cases, they also work mask the true nature of the aircraft’s radar signature.

On the J-20s nose, apertures for a missile approach warning system and what could eventually be a distributed aperture electro-optical system are seen, as are formation light strips embedded seamlessly into the jet’s skin. A single pitot tube in the exact same place as the one found on the F-22 is also visible.

Maybe the most interesting of all is the under-nose optical sensor system. In the past, China has been quite sensitive about showing off this chin-mounted sensor enclosure, with it being blurred out in official J-20 images and videos. For a long time, the enclosure didn’t really even exist, with an aerodynamic fairing acting as a placeholder. Then it seemed as if a fairly simple looking golden-mirrored enclosure with a far wider field of view than the one we see in these latest pictures appeared for a while. But this was likely just another placeholder—one with the added benefit of confusing foreign intelligence agencies.

Now, after years of avionics development, which has included the use of a specialized flying avionics laboratory, a real chin-mounted electro-optical capability looks to have become operational on China’s growing J-20 force, and the PLAAF is more willing to show it off in pictures. Remember, very little actually leaks out of China in regards to sensitive weapon systems without the government allowing it. In other words, they let us see what they want us to see.

Many have posited that this enclosure is intended to house an analog to the F-35’s Electro-Optical Targeting System (EOTS). But based on these images, it seems to have a far more limited purpose. 

The F-35’s EOTS enclosure offers a far wider field of view than the one seen on the J-20. This is necessary because it replaces the turreted targeting pods found on most western fighters that are used primarily to engage ground objects. With this in mind, the J-20’s optical sensor is likely air-to-air centric, with limited to no ground attack capability at this time., USAF

Instead of acting as a multi-role optical ground surveillance sensor and laser designator for dynamically targeting objects on terra firma—as is the case with EOTS on the F-35—this sensor’s enclosure appears to offer a far more limited field of view oriented towards the forward hemisphere of the aircraft. This points to it being used primarily as an air-to-air targeting and situational awareness sensor system. It’s worth noting that the F-35’s EOTS has integrated air-to-air functions as well, but air-to-ground remains its predominant use.

The J-20 was supposedly designed with a faceted, turret-mounted infrared-search and track (IRST) system—a critical sensor found on all Russian-built fighters that will allow the J-20 to better survive in a high-threat air combat environment even against America’s advanced stealth fighters (read all about IRSTs in this past feature of mine). Known as EORD-31, the J-20’s IRST lifts upwards out of its nose in front of the windscreen when in use. 

The large, diamond-like aperture for this system is clearly seen in photos of the jet, but its development could be delayed. In its place, Chengdu Aircraft Corporation engineers could have mounted a fixed IRST sensor in the stealthy ventral enclosure below the aircraft’s nose. This would allow for the J-20 to maintain a constant radar signature while using its IRST.

Alternatively, and more likely, the sensor inside the under-nose enclosure could be the other planned primary optical sensor for the J-20 that would work with the aircraft’s IRST, radar, end electronic support measures, and other combat systems. Dubbed the EOTS-86, this sensor surely operates at shorter wavelengths than an IRST and allows for long-range visual identification of potential threats. 

Used in conjunction with the IRST, it would allow the J-20 to silently detect and engage targets at beyond visual ranges—with the IRST detecting and the EOTS-86 identifying targets—even while operating under the most restrictive rules of engagement and without emitting any electromagnetic energy that can be detected by opposing forces. Even without the help of the IRST, the EOTS-86 would be able to be slaved to the J-20’s radar and could provide visual tracking and identification of targets in a way in which its radar cannot.

America’s F-15C/Ds are employing Sniper targeting pods in a very similar fashion and are slated to receive an advanced long wave-length IRST sensor as well. The Super Hornet will also feature a similar mix of capabilities and the F-35’s EOTS does long-range airborne visual identification as a secondary function, but the jet lacks a traditional IRST entirely.

But once again, this sensor cannot be used to the extent of the F-35’s EOTS. It would be used for target identification and possibly targeting from the frontal hemisphere only, not from steep angles below or even behind the aircraft as traditional targeting pods are capable of. It probably doesn’t have a laser designator either. But just as a situational awareness tool alone, and a passive one at that, it represents a potent capability even the F-22 doesn’t possess. 

It’s also possible that a true multi-role sensor similar to the F-35’s EOTS and its wide-field of view faceted sapphire glass enclosure will find its way on the J-20 sometime in the future as its mission set expands and as China’s sensor know-how improves. But that simply doesn’t exist at this time.

Chinese Internet

In these photos, we also get to see the fine details of the construction of the J-20’s outer airframe, and they look very similar to those found on the F-22, and in some cases, on F-35, although the aircraft doesn’t feature the continuous curvature structures of the latter aircraft and is far more akin generally the F-22 in this regard. Still, the construction quality appears to be quite impressive, with the near seamless joining of structures, sawtoothed access hatches and operating doors, edge-aligned apertures, and overall smooth surfaces. 

None of this comes as that much of a surprise as China has become a master at cyber espionage and the theft of classified intellectual property from America’s most capable defense contractors. In particular, these operations have targeted stealth aircraft programs, with vast amounts of data being stolen over the last decade or so. Still, as I have said for many years, the J-20’s overall shape and configuration has far more in common with defunct Russian fighter programs than American ones. 

The PLAAF’s ascent from a third-rate air arm to the USAF’s most threatening peer state competitor has been dizzying. And keep in mind, the J-20’s design is now nearly a decade old. China is working very hard at moving into the broadband low-observable combat aircraft arena in the form of unmanned combat air vehicles and possibly a new stealth bomber that could emerge from the shadows at any time. China’s medium-weight J-31/FC-31 stealth fighter is also showing signs of drastic maturation and is now in its second iteration of a flying prototype.  

The J-20 remains a highly interesting machine that will continue to improve in the coming decade. Powerplants have been a continuing issue for type, but China is making strides when it comes to indigenous engine manufacturing capabilities as well. But even without extreme kinematic performance, the J-20 appears to be a potent and stealthy sensor and weapons platform that could prove to be very challenging to deal with, especially when combined with creative cooperative platform tactics.

Yet what’s most impressive is that China has leapfrogged Russia when it comes to advanced fighter aircraft design in most respects. And by many indications, that disparity will continue to widen with each passing day as the J-20 fleet grows and evolves while Russia’s Su-57 program stagnates towards irrelevance

Contact the author: Tyler@thedrive.com