@tphuang and
@Deino.
I think if one looks at this conundrum it is very confusing. The arguments both for and against AL31FN are very cogent. The problem remains the lack of information about the Chinese engines. Basic information like thrust, MTBO, ability to produce in numbers is lacking. On the other hand the timing of the purchase points to PAF waiting for the WS10 to mature.
No one can deny that Chinese are very new in engine manufacturing. We know from looking at development of engines that newer engines often face reliability/technical issues which need ironing out.
Looking at it from PAF'S perspective they have so far resisted a transfer over to WS13 in spite of Chinese insistence. They have not even agreed to get the RD93MA for the same reason(possibly).
So my question remains why is it not plausible for PAF's J10 to have AL31 FN? It may be that with the advent of WS10 the Russians no longer have any interest in keeping AL31FN away from PAF since IAF has not bought any planes. PAF now have options and the simple adage of "if you cannot beat them join them" applies here.
I understand that the fact the Chinese have not bought any AL31s for 3 years means the news lacks credibility. Iam just saying we will need to wait and see how/when the information is released as arguments on both sides are very strong and no side can provide satisfactory answers as to why they feel the other possibility does not exist.
Regards
A