With China’s Chengdu J-20 fifth generation air superiority platform having entered service in 2017, making the country the first to deploy a stealth fighter outside the United States, new production facilities for the jet continue to be built apace across the country while dozens of new fighters are reportedly entering service every few months. While the bulk of China’s frontline fighters are advanced variants of the Su-27 flanker heavy fourth generation design, such as the J-11B or Su-30, the J-20 is set to be fielded in ever greater numbers alongside them. As a result sightings of the J-20 in regular People’s Liberation Army exercises are expected to become more common, and in recent weeks the first of the stealth fighters have been sighted in a new configuration - carrying external fuel tanks. While it was previously uncertain whether the J-20 had external hard points to deploy such systems, the deployment of two fuel tanks appears to mirror a common configuration for its counterpart in the United States Air Force - the F-22 Raptor.
Both the J-20 and the F-22 rely heavily on their radar evading capabilities to retain survivability in highly contested battle spaces, which in turn requires a low radar cross section provided by their stealth profile. Fifth generation stealth fighters are distinguishable by their sleek radar cross section reducing profiles, which necessitate the carriage of all fuel and munitions internally. For the U.S. Air Force the Raptor’s internal fuel carriage was insufficient for ferrying between the service's many airbases, particularly when travelling between bases in the Pacific theatre separated by wide stretches of ocean. Rather than rely on aerial refuelling, a more cost effective means of extending the Raptor’s range for non combat operations was to equip the fighters with two under wing external fuel tanks - which while undermining their radar evading capabilities also did much to extend their range. China’s People’s Liberation Army for its part appears to have reached the same solution - either by looking to the Raptor as an example or on its own initiative. China’s aerial tanker fleet is barely a small fraction of that of the United States Air Force, and to cross the country’s vast territory external fuel carriage has thus been an invaluable asset for the J-20. Though the fighter was designed specifically to operate over the Pacific theatre, rather than over Europe as in the case of the Raptor, and as a result retains considerably longer range, external fuel tanks remain an attractive option for further range extensions in peacetime.
Ultimate while the J-20, much like the F-22, is unlikely to ever carry fuel tanks on combat missions due to its vulnerability in such a configuration, this configuration remains valuable for peacetime operations. Indeed, recent footage of the stealth fighters flying over rural China has revealed that the J-20 can be equipped with not two, as in the Raptor's case, but a full four external fuel tanks for a vastly extended range. If the PLA Air Force had adopted this configuration based on that of the F-22 Raptor, it remains a possibility that the country's upcoming lighter J-31 may well imitate the American F-35A light stealth fighter - deploying not only fuel tanks but also missiles externally for an optional stealth profile reducing but firepower enhancing combat mode. Ultimately the course of China's stealth fighter program remains to be seen, but the J-20's deployment of external fuel tanks represents an interesting development.