China’s military modernization includes the rapid addition new J-20 fifth-generation aircraft. The increasing numbers of J-20s makes it important to discern if the Chinese fighter jet is comparable to the American F-35 Lightning II.
Department of Defense reports have noted that elements of the J-20 appear to mirror or mimic attributes of the F-35 and F-22 Raptor. However, at least in the short term, the People’s Liberation Army Air Force operates far fewer J-20s than the number of F-35s planned for acquisition.
That would seem to indicate an advantage for the United States. But China’s recent production rates and capacities, especially in the area of shipbuilding, may one day extend to aircraft construction as well.
The external configuration of the J-20 appears stealthy as it incorporates a horizontal, blended-wing body exterior with a rounded, gradually sloped structure. This design is intended to generate a much lower and less detectable radar cross section. Vertical structures or protruding formations can generate a stronger return signal in response to electromagnetic pings. Interestingly, the back portion of the plane appears to mirror an F-22 more than the F-35. The plane has dual exhaust suggesting the presence of a dual-engine design. While there are likely internal engines and measures of thermal management technologies, information on coating materials, heat signature management, and engines is likely difficult to come by.
Chinese newspapers have reported that the J-20 is built with a domestically-produced WS-15 engine. More recently, Chinese papers and the Department of Defense’s 2021 report on Chinese military power cited efforts to upgrade the J-20 to rival the F-22 with supercruise ability. However, F-22 supercruise, which enables the jet to sustain supersonic speeds without afterburners, may be difficult to replicate. It is not clear that Chinese engineering can actually match the F-22 in speed and aerial maneuverability. It may not rival the F-35 in these respects either, but the verdict remains unknown
There are other unknowns when comparing the F-35 and J-20. The true difference may reside in a series of unknowns, meaning superiority would likely be determined by mission systems, weapons and targeting, computing, and sensing. Regardless of the extent to which the external configuration of the J-20 appears similar to the F-35, the J-20 may be unable to rival the F-35 in terms of computing and sensor technology. Could a J-20 even see an F-35 before it were found and targeted by an F-35? Does it operate with any kind of high-speed computing able to organize incoming sensor data to present an integrated view to pilots? Does it have AIM-9X-like off-boresight targeting technology or other weapons with advanced guidance systems? Finally, are there built-in technical standards to upgrade the J-20 to match or rival the F-35 in coming years? The F-35, which will soon field unparalleled weapons such as the Stormbreaker, is engineered with an ability to accommodate new weapons, fire control technologies, and guidance systems as they become available in coming years. The Pentagon plans to fly the F-35 for decades into the future.
The answers to many of these questions may be unknown, but it does not seem likely that a J-20 boasts all these technologies. If not, it cannot match the F-35. But if it can, the balance of power in the air may be in danger.
Kris Osborn is the defense editor for the National Interest. Osborn previously served at the Pentagon as a Highly Qualified Expert with 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 Master’s Degree in Comparative Literature from Columbia University.