By Kris Osborn, Warrior

The People’s Liberation Army Air Force is now said to operate a fleet of 300 or more 5th-generation stealthy J-20 aircraft, yet the jet has rarely been seen beyond mainland China as part of what could be a deliberate effort to shield the operation of the mysterious plane from public view.  Certainly pictures exist and the J-20’s configuration has been known for many years now, and Chinese government-backed newspapers regularly cite the integration of its indigenously built WS-15 engine. 

Yet there has nonetheless been a curious absence of the J-20 in exercises throughout the region as well as an absence of J-20s among the aircraft known to cross into Taiwan’s Air Defense Identification Zone (ADIZ). Simply put, the J-20 has not been seen up close much at all, something which could be a deliberate PRC effort to increase mystery and unanswered questions about the jet. 

J-20 Flies Over Tsushima

Chinese state CCTV recently reported that the J-20 made a successful stealthy or secretive flight through the Tsushima Strait between Japan and Korea and remained undetected by US, Japanese or Korean sensors. A claim such as this would be quite difficult to verify and could simply be PRC scare tactics or propaganda, yet the possibility is likely being taken quite seriously at the Pentagon. Why wouldn’t Japanese or Korean radar, satellites or surface-to-air-defenses have “seen,” “captured” or “tracked” the J-20? The answer seems to invite considerable speculation, unless of course the J-20 was seen by US and allied sensors and is just not being acknowledged publicly. 

J-20 Stealth

If true …. What would this suggest about J-20 stealth and its radar signature? The question certainly invites speculation for a number of reasons, in part because the J-20’s external configuration appears “less stealthy” than an F-35 or F-22. While the J-20 has angled canards and an elongated fuselage with some protruding or pointed structures, contours likely to generate an electromagnetic return “ping” or signal to ground-based radar. The J-20 also has a larger nose radome than an F-22 Raptor which is optimized for both stealth and speed. The J-20 is a fast aircraft too, as it is cited as being capable of Mach 2, a speed faster than the F-35s Mach 1.6 yet slower than the Mach 2.25 speed of the F-22. Perhaps the J-20 is built with an unprecedented kind of radar absorbing coating materials? Perhaps the jet incorporates never-before-seen thermal management?  Perhaps it flies with a combination of speed and agility which, when combined with stealth, makes it very difficult to “see” or “track.”  Does its stealth properties make it appear like a bird or small object to radar … as is the case with full flying-wing aircraft such as the B-2, B-21 or emerging Chinese H-20? 

Air Defenses

The more likely explanation, should the PLA claim that the J-20 was undetected be true, may pertain to the presence or absence of Japanese and Korean sensors and air defenses. The incident may simply mean that Japan needs to position radar systems and air defenses in position to track and detect its coastal air space bordering Korea.  There is also the question of US Navy Aegis radar, although no ships armed with this kind of mobile, maritime ballistic missile defense were likely operating within view of the Tsushima Strait. However, ship integrated AN/SPY-1v radar now built into US Navy Flight III DDG 51 Destroyers operate with much greater range, sensitivity and image fidelity when compared with standard ship-integrated radar. AN/SPY-1 radar is 35times more sensitive than previous ship radars, and it can detect very small objects with great precision from unprecedented distances, however Aegis Combat Systems radar is primarily focused upon air and cruise missile defense as well as ballistic missile defense, meaning it does not specifically search for stealth aircraft.  It would nonetheless be quite relevant to explore whether AN/SPY-1 radar integrated with Aegis Combat System Baseline 10 would be positioned to detect stealth aircraft. 

Kris Osborn is the President of Warrior Maven – Center for Military Modernization. Osborn previously served at the Pentagon as a highly qualified expert in the Office of the Assistant Secretary of the Army—Acquisition, Logistics & Technology. Osborn has also worked as an anchor and on-air military specialist at national TV networks. He has appeared as a guest military expert on Fox News, MSNBC, The Military Channel, and The History Channel. He also has a Masters Degree in Comparative Literature from Columbia University