Why do China’s sixth-gen stealth fighters have different designs?

The smaller – and more manoeuvrable – of China’s two recently revealed sixth-generation stealth aircraft is likely to form the country’s future cohort of carrier-based warplanes, according to Chinese analysts. The smaller fighter jet was spotted during its maiden test flight over the northeastern city of Shenyang late last month. On the same day, a larger, three-engine aircraft with a tailless diamond-wing design was seen over Chengdu. The city, in China’s southwest, is the home base of Chengdu Aircraft Industry Group, which manufactures fighters including the J-20, the People’s Liberation Army’s answer to the US Air Force’s F22. According to Chinese military commentator Du Wenlong, the two sixth-generation jets are based on different design concepts aimed at meeting the requirements of different branches of the armed forces. The plane spotted over Chengdu “prioritises stealth capabilities, long range, and high payload capacity” while the smaller, two-engine aircraft with a tailless lambda-wing design “is likely to be a development model of a carrier-based fighter”, he said. The smaller jet is likely to be made by Shenyang Aircraft Corporation, which already produces several carrier-based fighters and has its base near where the warplane was seen last month. Du said the two aircraft “will have a strong impact on the competition for future air combat and air superiority”. Footage of the two models has been circulating on Chinese social media since December 26 – the 131st anniversary of the birth of Mao Zedong, founding father of the People’s Republic of China. More footage emerged on Saturday, showing what appears to be a second test flight for the Shenyang aircraft – referred to as the J-50 by some military observers and enthusiasts – with clearer images detailing its configuration and manoeuvrability. Another Chinese military expert, who asked for anonymity, said the Shenyang plane featured a foldable vertical tail design, which could allow for flexible adaptation between stealth and high-manoeuvrability configurations. “It can be transformed into a vertical tail configuration, partly because it might need to land on an aircraft carrier, which requires complex control,” the analyst said. “Additionally, in close-range dogfights, stealth becomes less crucial, and at this point, deploying the vertical tail can significantly enhance manoeuvrability.” China’s carrier-based air fleet mainly consists of the J-15 fighter jet – often referred to as the “Flying Shark” – which is deployed on its first two carriers, the Shandong and Liaoning. In November, China unveiled a more advanced carrier-capable J-35 stealth fighter, along with the J-15T, an improved version of the J-15 designed with catapult launch systems. Both warplanes are expected to be deployed on the Fujian, China’s latest carrier – and its first domestically designed and produced – to form a high-low mix to maximise their combat strengths. Song Zhongping, another Chinese military commentator, also said the fighter jet seen over Shenyang could be used for carrier-based operations. According to Song, the two aircraft manufacturers “are competing with each other”. If the performance of both was outstanding, “they could be used by different branches of the military”, he said. There has been no official confirmation of the new aircraft but the Chinese military has indirectly endorsed their debut. A New Year’s Day music video from the PLA’s Eastern Theatre Command featured a ginkgo leaf that looked very much like one of the jets. Malcolm Davis, a senior analyst at the Australian Strategic Policy Institute, said the aircraft opened up a long-range air dominance capability that could challenge Washington and its allies if they could not shift their thinking on air operations. The US is developing its own sixth-generation fighter, under the Next Generation Air Dominance (NGAD) programme, which is expected to feature advanced stealth capabilities, adaptive engines and an ability to control drones. “My guess is that China will want to bring these aircraft into service quickly, especially given that the NGAD programme is on hold pending review in the next Trump administration,” Davis said. If China could move to operational deployment for both of its sixth-generation aircraft within this decade, it could possibly gain a “qualitative advantage” over the US, he said. “That would have some serious operational and strategic implications for the US-China military balance and China’s intentions vis-a-vis Taiwan.” According to Davis, the Chengdu plane – referred to as J-36 – is not an aircraft for “dogfighting” or the intense manoeuvrability of air combat. Instead, its design implies a supercruise ability, meaning it could be able to fly supersonically without using afterburner, extending its range and increasing responsiveness. “The J-36 is likely to be the coordinating node in a ‘system of systems’ that brings together crewed and autonomous platforms as a network, and to provide forward targeting data for other platforms in other domains, such as naval surface combatants.” Davis added that, based on present discussions about combat radius, the J-36 was likely to be able to project power out to the second island chain or operate between the first and second island chains with long endurance on station. The smaller J-50 probably has a correspondingly reduced combat radius compared to the J-36, and is likely to be used for roles within the first island chain, according to Davis. Timothy Heath, a senior international defence researcher at US-based think tank Rand Corporation, said the third engine and large bay of the Chengdu variant could open options for it to serve as a stealthy fighter-bomber. The Shenyang aircraft could be used for more conventional multirole missions, including fighter, strike, and surveillance operations, he said. “It could be even more powerful if paired with the Chengdu variant stealth aircraft, which could provide radar and warning, electronic warfare and UCAV [unmanned combat aerial vehicle] support.”

Why do China’s sixth-gen stealth fighters have different designs?

The smaller of the advanced jets is expected to be carrier-based while the larger plane could become a fighter-bomber, observers say