Recently, Shenyang Aircraft Corporation (SAC) released a promotional video titled “We Walked Together.” On the evening of July 1, CCTV’s Xiaoyang Video shared this promotional video, revealing the new J-31B “Gyrfalcon” stealth fighter at the end. If the video producer is correct, this new “J-31B” appears to be significantly larger than the earliest FC-31 model, upgrading from a medium fighter to a heavy fighter. It is also equipped with side weapon bays, capable of carrying two combat missiles each.
According to the official website of SAC, the company is a large modern aircraft manufacturer integrating scientific research, production, testing, flight testing, and service support. It is one of the key enterprises of the Aviation Industry Corporation of China (AVIC). Founded on June 29, 1951, it is one of the 156 key projects of China’s First Five-Year Plan, and is known as the “cradle of Chinese fighter jets.”
Data shows that the “Gyrfalcon” fighter is an independently developed medium-sized fifth-generation stealth fighter by SAC. Ten years ago, the “Gyrfalcon” fighter debuted at domestic and foreign air shows, then codenamed J-31.
Earlier, the website of the Ministry of Industry and Information Technology (MIIT) reprinted a Xinhua News Agency report disclosing that the J-31 was initially not a military project but was independently funded and developed by the company. “If the J-31 project is ultimately successful, it will undoubtedly blaze a new trail.”
Now, Xiaoyang Video has confirmed that this fighter is officially named J-31B. In the footage, the front side of the aircraft is marked with “J-31B.” Additionally, Xiaoyang Video gave a close-up shot of the aircraft’s side weapon bay, labeled “weapon bay.” The close-up shows two missiles loaded in the side bay.
The simultaneous voiceover in the video explains: “From generation one to generation five, from land-based to sea-based.” This may imply that this type of fighter could potentially be deployed on aircraft carriers and other large surface ships as a carrier-based aircraft.
The video discloses significant information about the side weapon bay design of the J-31B fighter.
Firstly, reviewing the current active stealth fighters of various countries, it is very rare for medium-sized fighters to have side weapon bays that can load two missiles. This means the J-31B possesses a payload capacity comparable to heavy fighters. Furthermore, this design indicates that the fighter excels in structural optimization, space utilization, and engine performance. From the footage of the J-31B’s side weapon bay, it can at least carry two missiles. Combined with the main weapon bay similar to the J-20, the J-31B may carry at least four PL-12 medium-range air-to-air missiles. If the main weapon bay is replaced with ground/anti-ship weapons, it will not only possess the capability of concealed approach and aerial bombing but also form a multi-role fifth-generation fighter with stealth, situational awareness, and full-domain offensive capabilities, capable of performing various missions!
Additionally, the footage shows that the J-31B’s side weapon bay adopts a “single-door” design, consistent with China’s current heavy stealth fighter, the J-20.
In 2018, the J-20 participating in the air show fully opened its main weapon bay (underbelly) and side weapon bays (side of the aircraft) for the first time, displaying a full load of ammunition during a flight demonstration. This demonstration showed that, compared to the “double-door” side weapon bay of the US’s active heavy stealth fighter F-22, the J-20’s side weapon bay uses a “single-door” design.
At that time, the Overseas Network interpreted that the J-20’s side weapon bay is unique and structurally simpler than the F-22’s side weapon bay. The F-22’s side weapon bay door cannot close during the entire missile launch process, while the J-20’s side weapon bay door can close again after the missile is moved out, leaving only the missile suspended outside the aircraft, reducing the impact on the fighter’s stealth performance and aerodynamic shape.
This slight difference in design details leads to different air combat modes relying on side weapon bay ammunition between the F-22 and the J-20.
Chinese military expert Song Xinzhi once explained in a CCTV program that opening the weapon bay of a stealth fighter affects its stealth performance, increasing the probability of being detected by radar. The unique design of the J-20 can minimize this disadvantage as much as possible.