Chengdu J-20Aircraft model
The Chengdu J-20 “Powerful Dragon” is a fifth generation dual-engine stealth fighter aircraft prototype developed by the Chengdu Aircraft Industry Group for the Chinese People’s Liberation Army Air Force. In late 2010, the J-20 passed a high-speed test. Wikipedia
There are too few of them.
China has some hiccups to overcome
by Zachary Keck
Key Point: Engines that allow fighters to reach supersonic speeds without using afterburners help them maintain their stealth.
China’s first fifth-generation aircraft is having a major issue.
As Dave Majumdar previously covered, China recently declared that its J-20 fighter jet had attained initial operational capability. “China’s latest J-20 stealth fighter has been commissioned into the air force’s combat service,” China’s Defense Ministry said on February 9. Chinese analysts touted the country’s achievement as breaking the Western stranglehold on stealthy aircraft. “The J-20 will also change the history of the air force in Asia-Pacific region. In the past, only the U.S. and its allies like Japan were capable of arming stealth fighter jets. But now, their monopoly in this region has been broken by China’s J-20,” Song Zongping, a military expert, was quoted as saying in official media.
China has indeed long depicted the J-20 as a competitor to America’s fifth-generation jets, the F-22 and F-35. But a new report casts doubt on those claims. Specifically, the Hong Kong–based South China Morning Post (SCMP) reported that “China rushed its first advanced stealth fighter jet into service ahead of schedule last year, using stopgap engines, in the face of rising security challenges in the region.” According to SCMP, that “means its capabilities will be severely limited, affecting its manoeuvrability and fuel efficiency as well as its stealthiness at supersonic speeds.”
The story notes that the J-20s were initially slated to be powered by a specially designed W-15 engine. However, during testing in 2015, the W-15 engine exploded. Although no one was injured in the explosion, Chinese engineers have not been able to fix the engine. One source told the Hong Kong paper that the “reasons it happened were complicated, with one being the quality control of its single-crystal turbine blades, the key component for such a powerful turbofan engine.” More concretely, the W-15’s single-crystal turbine blades have been unable to handle the high temperatures and maneuverability of the J-20.
An engine that can handle these functions is essential for fifth-generation aircraft. As the article notes, engines like the F-22’s Pratt & Whitney F119 allow fighters to reach supersonic speeds without using afterburners, which allows them to maintain their stealth. Without an engine like this, Beijing’s J-20 would lack stealthiness while traveling at supersonic speeds.
The issue does not look like it will be resolved in the near future. A second Chinese military source claimed to SCMP: “Chinese technicians are able to produce cutting-edge-quality single-crystal turbine blades when concentrating on a specific single item. But they’ve still failed to turn the advanced technology into a standard product for mass production. It’s a bottleneck problem that needs more time to overcome after countless experiments and tests, based on Western experiences.”
For the time being, then, China’s new combat ready J-20s are using WS-10B engines. According to SCMP, the WS-10B is a modified version of the WS-10 Taihang engine, which were built to power China’s J-10 and J-11 fighters. Those fighters are labeled as fourth-generation jets. The WS-10B’s thrust-to-weight ratio is not able to power the J-20 to supersonic speeds without the use of afterburners.
This is not the first time that the J-20 has required new engines. Initially, China had used two Russian AL-31 engines to power the J-20 fighter jets. These engines are even less capable than the WS-10B ones that China produces domestically. Beijing has pushed Moscow to sell it more advanced engines but Russia has refused because of concerns that China will reverse engineer them, as it has done with other military systems.
China’s J-20 fighter can get ‘beastly’ if it has to
Chengdu stealth fighter spotted equipped with pylon adapters under its wings, sparking new speculation
By DAVE MAKICHUK
June 4, 2020
The J-20 is believed to be equipped with subsystems and field signature reduction technology that meets the classification of a “fifth-generation” aircraft. Credit: The Drive.
Like the US forces’ F-35 fighter jet, China’s Chengdu J-20 loses some of its stealth capability when it carries a load of larger weapons — this is jokingly called “beast mode.”
Recently, the J-20 has been spotted equipped with pylon adapters under its wings, indicating a new range in combat capability, The Global Times reported.
A J-20 prototype taking a test flight had two external pylon adapters, one under each side of its wings, and could carry a total of four extra missiles, Shanghai-based news website eastday.com reported, citing a recent photo widely circulated on Chinese social media.
Judging by a performance flight at Airshow China 2018, a single J-20 can carry at least four PL-15 missiles in its main weapon bay and two PL-10 short-range combat missiles in its side weapon bays, when not using external adapters, The Global Times reported.
Usually, stealth aircraft hide their weapons in bays to keep a low radar profile, making them difficult to be detected, and using external pylons to carry weapons will make them less stealthy but more powerful, a Chinese military expert who asked for anonymity told the Global Times on Wednesday.
The warplanes can choose different types of loadouts according to different mission requirements, the expert said.
This is similar to the US’ F-35 fighter jet, which has a “stealth mode” that can only carry a small amount of internal ordnance and a “beast mode” that can carry a lot more internal and external ordnance, the eastday.com report said.
Stealth aircraft can use “stealth mode” to seize aerial superiority, and once the sky is clear and safe, they can ditch stealth and switch to “beast mode” by carrying more munitions via external adapters and launch extended attacks, the report said.
The photo indicates that the J-20 could enter a “beast mode” like the F-35 when engaged in low-risk and low-threat missions, eastday.com reported, noting that the J-20 could also carry external fuel tanks for extended range.