Cyber Espionage And Reverse Engineering Did Not Make Chengdu J-20 A Stealth Aircraft

A single-seat, fourth generation multirole fighter aircraft, the Chengdu J-20 is manufactured by Chengdu Aircraft Industry Group (CAIG) of China.

Potential customers of the J-20 are Pakistan, the Middle East, Latin America, South-East Asia and African countries.

China’s J-20 stealth jet, believed to be a copycat design of the US-made F-35, is now duplicating same old fourth-generation non-stealth feature – to carry weapons on external pylons.

The J-20 supposed to carry missiles and bombs in an internal weapons bay to avoid radar detection. However, for some reasons heavier weapons load, these are mounted on external pylons, at the expense of stealth. Here’s why?

After Copying F-35's Stealth, China's J-20 Duplicating its Non-Stealth Features

Chinese local media posted photograph showing a J-20 prototype undergoing a test flight with two external pylon adapters, one under each side of its wings.

The Chinese jet previously had the capacity to carry four PL-15 missiles in its main weapons bay and two PL-10 short-range missiles in its side weapons bay. The external adapters will enable the jet to carry four more missiles.

In addition, the Chinese media speculated that the J-20 fighters could also carry external fuel tanks for extended range which will enhance radar signature significantly.

Cyber Espionage

The Chengdu tried to adopt Electro-Optical Targeting System (EOTS) in terms of shape and placement. In 2007, Chinese hackers allegedly stole technical documents related to the F-35 from Lockheed Martin.

Daniel Coats, in a congressional testimony published in May 2017, named Russia, China, Iran and North Korea as “Cyber Threat Actors.”

“Adversaries will continue to use cyber operations to undermine U.S. military and commercial advantage by hacking into U.S. defense industry and commercial enterprises in pursuit of scientific, technical, and business information,” Coats stated.

“Examples include theft of data on the F-35 Joint Strike Fighter, the F-22 Raptor fighter jet, and the MV-22 Osprey. In addition, adversaries often target personal accounts of government officials and their private-sector counterparts. This espionage reduces cost and accelerates the development of foreign weapon systems, enables foreign reverse-engineering and countermeasures development, and undermines U.S. military, technological, and commercial advantage.”

Putter Panda

The group is known as “Putter Panda” by security researchers, and Crowdstrike believes it is located in Shanghai, China, housed in buildings belonging to the People’s Liberation Army or PLA.

Putter Panda is thought to have been active since 2007 at least. It targets American and European defence and satellite and aerospace industries, using exploits in popular applications such as Adobe Reader and Microsoft’s Office productivity suite.

Stealing Engine Technology By Turbine Panda

The hacking team targeted companies between 2010 and 2015, and successfully breached C919 suppliers like Ametek, Honeywell, Safran, Capstone Turbine, GE, and others.

Comac C919
Image credit: Aerotime

But unlike in other Chinese hacks, where China used cyber-operatives from military units, for these hacks, the MSS took another approach, recruiting local hackers and security researchers.

The group, which Crowdstrike said it tracked as Turbine Panda, was extremely successful. The US cyber-security firm points out that in 2016, after almost six years of non-stop hacking of foreign aviation companies, the Aero Engine Corporation of China (AECC) launched the CJ-1000AX engine, which was set to be used in the upcoming C919 airplane, and replace an engine that had been previously manufactured by a foreign contractor.

Radar Cross Section

The Chinese used materials to suppress frontal radar signature is interesting. Chinese Publications show that the Chinese are making a substantial investment in use of materials to reduce radar signature and have produced large volumes of research results. So far, there have been no Chinese public disclosures on materials that make a substantial reduction of signatures across a broad range of air combat radar frequencies.

The J-20 is equipped with a fuel-receiving probe on the right side of the cockpit, China Central Television (CCTV) reported.

J-20 Refueling Probe

Embedded under the fuselage, the probe only pops up when the fighter jet conducts an aerial refueling mission. When the refueling is completed, the probe is retracted into the fuselage, according to a video released by CCTV in the report. During refueling, the aircraft’s radar cross section will increase significantly.

Failed Attempt to Adopt As Naval Variant

In a program aired on its International Mandarin channel, PLA Rear Admiral Zhang Zhaozhong, also a well-known military commentator, admitted that putting J-20 on carriers was rather “contrived”, as the fighters were never designed to be carrier-based aircraft.

Naval J-20

“J-20’s structural design and components are all intended for use as a land-based warplane and thus its structural strength may not have been reinforced for take-off from or landing on a carrier, as in these circumstances the plane would have to withstand huge counterforce and inertia,” Zhang said.

Nor are J-20’s wings foldable, to enable it to be parked in the hangar below the carrier’s flight deck, as space is always at a premium on a sea-going airbase.

External Weapons Pylons

Lock-on after launch capability is not an easy one to achieve. It is technologically complex, requires deep systems integration (software architecture permitting), and robust testing using live missiles, and thus it is expensive. Chinese heat-seeking missile can take longer to launch, an open weapons bay during prolonged maneuvering while the missile hangs out on its rail potentially could damage the weapon bay and the door or accidental release of the missiles.

China's J-20 fighter can get 'beastly' if it has to
External Weapons of J-20

Radar signature becomes a small factor when fighting for one’s life at close range, having a reliable missile ready to make a u-turn off the rail and subsequently turn your enemy into chaff is so important that is can be seen as a life and death requirement especially for a big, not remarkably maneuverable fighter like J-20, Chinese engineers decided to sacrifices stealth for close combat engagement.

Another point to be taken from the J-20’s short-range air-to-air missile launch mechanism revelations are that designers absolutely thought it was necessary to give this jet high-off-bore-sight close range missile capability from day one, and in a reliable and persistent nature when needed.

This could be due to lack of maneuverability of aircraft, which I have said for years that the American and Taiwanese fighter can take out J-20 fighters using AEW&C, C2 and connectivity nodes from land, air and sea platform.


The J-20 prototype is powered by Saturn 117S engines supplied by Russia. Each engine produces 32,000lb of thrust. The Saturn engines are smoky and provide opportunity to be targeted by enemy heat-seeking missiles launched from fourth generation fighters.

The production aircraft is powered by two WS-10G thrust vectoring turbofan engines each generating 30,000lb of thrust. The engine is being designed and manufactured by Shenyang Liming Aircraft Engine Company. It will feature a single high-pressure turbine, dual low-pressure turbine, annular combustors and compressors.

This image has an empty alt attribute; its file name is 166203.jpg
WS-10 Engine

Shenyang WS-10 was developed on the basis of the French-American aircraft engine CFM56 and copied from the Russian AL-31F, designed to replace foreign aircraft engines on Chinese-made military aircraft and develop their own propulsion industry.

The WS-10G will be fitted with thrust vector controlled (TVC) nozzles to decrease radar cross section (RCS) and infrared (IR) emissions. The diameter of the engine is 0.95m. The dry weight is 1,494kg.

Under current form, both Russian and Chinese engine scarifies stealth features, –does not have the capability to enable J-20 achieve supercruise, hence J-20 must use afterburner to reach supersonic speed.

Fourth-Gen Su-30MKI Can Detect J-20

The Indian Defence Research Wing says its Russian-made Su-30MKI fighter jets can spot the supposedly-stealth J-20s, and has already observed them in flight.

Indian Air Force Chief Marshal Birender Singh Dhanoa said the “Su-30 radar is good enough and can pick it (J-20) up from many kilometers away,” according to Indian news website Zee News.

India has been basing its Su-30MKIs in the northern part of the country to counter China’s deployments of J-20s, which struggle to take off in the high altitudes near Tibet, Zee News reported.

The Su-30MKI represents a new and effective Russian jet with an advanced array of radars that Justin Bronk, an air combat expert at the Royal United Services Institute told Business Insider could probably spot the J-20.

“It is entirely possible that the Su-30MKI can pick up track information on J-20 from quite long ranges,” Bronk said. “But what I would expect is that those tracks may be fairly intermittent and dependent on what headings the J-20 is flying on relative to the Sukhoi trying to detect it.”


The J-20 is a Chinese experiment to built a domestic fighter jet through espionage and IP theft, but the Chengdu J-20 is long way to becoming a stealth fighter.

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