Great so indigenous engine is on new serial production WS10C?
And what is WS15? How much more powerful is it and is it even worth making WS10C when soon they will be replaced with WS15?
because soon they will have Russian, WS10C and WS15 on J20, adding to logistics issue
why not just wait till WS15
WS-10 on J-20 are suspected to be around the 135-137kN range, i.e, depending on how much the J-20 weights they could be perfectly adequate for hybrid strike / interception roles. The WS-15 is supposed to be a Chinese next-generation engine, somewhat behind the F135, that will score between 160-197 kN.
As for rushing to WS-15, Chinese engine development traditionally has been an exceptionally painful process. The choice is between deploying the J-20 now or waiting for WS-15; if the Pentagon believed that the J-20 wouldn't be IOC before 2020, that's because they were watching the engine process.
But look at the F-35 as an example. It's an anemic dogfighter, although competent, in part because its thrust to weight is so mediocre. However, it's still competitive as a mass-produced strike aircraft because of the combination of its EODAS sensor system and its shaping / materials stealth.
If the choice for China is between getting a fighter in the air (J-20 with WS-10) or waiting for better engines, rushing to get the J-20 in the air with inferior engines can still present a competitive aircraft and an adequate capability.
As the engines is only one subsystem of an aircraft, it shouldn't be impossible to retrofit with WS-15 once the latter is ready.
