Guys ... can we please stick to the topic - which is the C929 - and leave out all Russian projects?
In fact they are irrelevant and could better be discussed in the Russian thread!
Honestly, your demand is almost a mission impossible. If you ran a SinoTofuForum, there would also be a discuss on whether or not China could make high quality tofu without Russian soybean....
On a serious note, since unlike Russian current self-sufficiency policy, the project C929 is open to use foreign components if they are better than their Chinese counterparts and Russians also has expressed their desire to be a component supplier of the project, discussions on Russian ability of making world-class products to meet C929's requirements will always exist under this topic. To support the claims that Russian manufactures are qualified, pro-side needs to prove that Russia has already successfully used claimed technologies on its own projects like MC-21, and the con-side needs to prove that Russia hasn't such technologies, then these discussions divert to Russian projects instead of Chinese.
I think instead of banning such seemingly off-topic discussions which actually are not entirely irrelevant, it would be better to end these discussions when both sides could not present evidence to support their claims or either side refused to accept the evidence which the other side provided. For example: I speculated that Russia might have used made-in-China carbon fiber to replace made-in-Japan one and gelgoog claimed that Russian had made better carbon fiber. Since both sides can't provide solid evidence except some rumors from social media, the discussion should end here.
Another example is that I think I have provided enough evidence to prove MC21-310's OEW has been increased but gelgoog obviously refuses to accept it. I think the discussion also should be ended.
