|China's J-20 stealth fighter.|
China has decided to equip its next-generation J-20 stealth fighter with an upgraded home-made engine in place of the current Russian one.
A military insider told the South China Morning Post that Chinese engineers determined that their WS-10C, the modified version of the WS-10 engine, was as good as Russia's AL-31F engines.
"It's impossible for China to rely on the Russian engine, because Russia asked China to purchase more Su-35 fighter jets in exchange for the AL-31F engine deals," the insider said.
A photo posted online by aviation enthusiasts in late 2020 showed a prototype of the J-20 with the new serial number "2021" and not powered by a Russian engine. It proved that China produced new upgraded J-20 prototypes for flight testing.
The insider confirmed that the new J-20 prototype was powered by two WS-10C engines, but that this is a provisional choice.
"The use of WS-10C to replace Russian engines was caused by the failure of WS-15 to pass its final evaluation in 2019," the insider said.
"The air force is not happy with the final results, demanding that engine technicians modify it until it meets all standards, for example matching the F119 engine used by the Americans' F-22 Raptor."
The Covid-19 pandemic has impacted modification work on the WS-15 over the past year, the insider said.
A modified version of the J-20B went into series production in June last year after Chengdu Aerospace Corporation (CAC), the developer of the J-20, introduced a fourth production line in 2019. Each line has the capacity to produce about one J-20 per month.
These mass-produced J-20s will still be equipped with Russian engines because testing the WS-10C will take at least a year, according to the insider.
At the beginning of its deployment in the Chinese Air Force since 2017, the J-20 used the WS-10B, a variant of the WS-10, as a temporary engine. The WS-10B is an improved variant of the Taihang WS-10 engine designed for fourth-gen Chinese J-10 and J-11 fighters.
Chinese engineers have been developing high-thrust WS-15 turbofan engines for the J-20 since 2006, but the work has fallen behind. Problems include an engine explosion during a ground test in 2015.
Macau military observer Antony Wong Tong said postponing the final launch of the WS-15 could affect the long-term development of the Chinese aircraft.
"The J-20 needs to shorten its transitional period and apply the WS-15 as quickly as possible because the US is expected to deliver their sixth generation aircraft in about a decade," Wong said.
The first flight of the J-20 took place in 2017, ahead of time, after US President Donald Trump ordered the Pentagon to deploy F-35 stealth fighters in Asia Pacific. The tension between the two superpowers for control of this area is very high as it includes the epicenter of global commercial shipping.
Written by Matteo Sanzani