A series of recent images has confirmed that China is no longer reliant on Russian turbines to power it's burgeoning fleet of combat aircraft. New-build production J-10C and J-20 aircraft are leaving the Chengdu factory with indigenous WS-10 "Taihang"engines installed.
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Previously these aircraft were delivered with variants of the Russian-produced Salyut AL-31 engine.
In the case of the J-20 pictured below, the engine is the WS-10C variant, a non-thrust vectoring model. This came as a surprise to some observers who expected a TVC-capable WS-10 to be installed on the aircraft, but it may be that full TVC integration with the aircraft flight controls just isn't ready yet.
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Alternately, the long postulated "stealth interceptor" aka "AWACS killer" role of the J-20 may not need TVC.