MELBOURNE, Australia — China has completed the development of its next generation of indigenous military aircraft engines and will start mass production once supply chain issues with advanced alloys are resolved, according to a senior official from a local aerospace materials research facility.

Speaking at an aviation investment summit in Tianjin, China, on March 17, Zhang Yong, a project leader at the Beijing Institute of Aeronautical Materials, told the audience that developmental bottlenecks for the WS-19 and WS-20 turbofans as well as an unidentified next-generation engine have been surmounted.

However, he added, material supply chain issues for the manufacture and delivery of the advanced alloys that will be used in the engines’ production still need to be ironed out. The official did not specify the supply chain problems.

The WS-19 afterburning turbofan is under development to power the Shenyang J-35, a next-generation fighter jet meant to operate from aircraft carriers for China’s People’s Liberation Army Navy. The WS-20 is a high-bypass turbofan engine that will power the Xi’an Y-20 airlifters operated by the People’s Liberation Army Air Force.

The Y-20 is currently powered by the Russian D-30KP low-bypass turbofan, which is also used by the Xi’an H-6J/K/N bombers of both armed services.

Zhang also confirmed that the WS-15 afterburning turbofan is ready for mass production. The engine will be used for later variants of the Chengdu J-20 stealth fighters of the PLAAF.

The WS-15, rated at 181 kilonewtons, is expected to provide a supercruise capability for the J-20, enabling it to attain supersonic cruise speeds without the use of its afterburner, which reduces fuel consumption.

Zhang also said at his presentation that China managed to achieve “98% localization” for WS-10C engine, which is powering the J-20s currently being delivered to the PLAAF. Other variants of the WS-10 equip China’s Chengdu J-10, Shenyang J-11B and J-16 fighter fleets.

He did not provide details on the remaining 2% input, although it’s likely related to components or materials China still sources from foreign providers.