Various Japanese critics in the field of quality management and military analysis.
There are also various reports by nations that say they will not import anymore PRC made equipment like the Nigerian Air force stating that in the past 5 years 4 out of 12 fighter planes crashed due to engine failures and the rest are grounded and are used for static training at their academy.
I also hear that Pakistan had rejected PRC engines due to quality issues and are favoring Russian made ones for their fighter planes.
All varying degrees of truth and untruth, to my knowledge.
-Japanese critics are not particularly relevant for Chinese military analysis I'm afraid. Credibility and claims would have to be established on a case by case basis.
-list any reports by nations which say they will not import Chinese military equipment?
-do you have a report for Nigeria not buying anymore Chinese equipment? Also please remember that Nigeria only has 12 fighter jets in service all of which are F-7s anyway.
-Pakistan? Are you talking about JF-17? Because the WS-13 isn't even ready for JF-17 yet as far as we know, so it shouldn't even be on offer.
But in the end none of these relate to either WS-10 or SAC Flankers anyway.
Here is a comment from the horse's mouth within Wiki;
Do I need to go on?
Actually yes you do, because this part that you quoted from Lin Zuoming is very old news and at that time the WS-10 was not even installed on any aircraft at that time.
More importantly the part of the wikipedia entry citing 30 hours is from the Washington Post -- I remember when that first came out and was roundly dismissed. Unfortunately the Washington Post isn't exactly considered a respectable source nor is the author of that article considered an expert in these matters ,and I don't think any Chinese language article or even rumour has corresponded with that claim either.
More importantly even if all of that quoted part you mentioned was true, it still doesn't relate to your claim either.
So let me repeat, do you have any real sources for where you heard that "half of them are in constant repair"?
I'll save you the trouble -- how about you just acknowledge that you pulled it out of your backside. If such a claim or fact existed then we would well be aware of it here.
please remember that all of us (correction: or at least many of us) here have spent years carefully watching and scrutinizing every detail and rumour surrounding Chinese military matters including big ticket items like WS-10.
BS claims don't fly well here.