The key difference between the two programs, and one crucially relevant to our discussion at hand, is that the J-20 program was borne out of a PLAAF requirement (i.e. a military-sanctioned tender) while the FC-31 is an independent project by SAC. The J-20 program would have had access to PLAAF funding, among other luxuries, that the FC-31 program would not. The same principle could be applied to other big-ticket items, such as the 001A or Divine Eagle UAV.
Funding, au contraire, is a huge factor in the success of a military project. The FC-31 used funds directly from SAC itself rather than China's DoD, so it is definitely a burden for SAC. The YF-23, which supposedly out-performed the F-22 in kinematics, was canceled precisely due to lack of funds.
You seem to consider "the lack of funding" as a root cause, which potentially leads to all sorts of issues with the J-31. I, on the other hand, think of "lack of funding" as an effect. In other words, what makes people unwilling to give them the money? Most likely because of lack of enthusiasm of the design?
Why would the PLA still not want to fund the J-31? If the J-31 is such a technologically advanced piece of equipment and provides such strategic and tactical advantages for the PLA, what is the PLA waiting for? They should have pounced on it by now. Why are they allowing the SAC to shoulder such burden, which should never be SAC's to begin with?
It is not because of lack of trying. We have seen interviews describing some PLA personnel visiting and inspecting the J-31 many times. Yet, the SAC is still shouldering the burden. The J-31 cannot get DoD and PLA funding because of unknown causes, most likely dissatisfactory designs. The lack of enthusiasm on the part of the PLA is a huge flashing neon sign "we don't like it!"
Funding, au contraire, is a huge factor in the success of a military project. The FC-31 used funds directly from SAC itself rather than China's DoD, so it is definitely a burden for SAC. The YF-23, which supposedly out-performed the F-22 in kinematics, was canceled precisely due to lack of funds.
You need to look at the other way around. The YF-23 was cancelled not because of lack of funding. It could not obtain funding because it lost competition to the F-22 and because no one was interested in it. In other words, it couldn't find funding because people in the government had already decided to abandon it.
The lack of funding is NOT the cause, but an effect stemmed from other more fundamental issues.
Lack of publicity does not necessarily imply that there is a lack of progress. Granted, the FC-31 seems to be on the backburner until the PLA makes its decision, but keep in mind that it has been increasingly difficult to gauge the progress of Chinese military projects in recent times. The J-11D, for instance, remained unknown to the public until it conducted its maiden flight. Same thing could be said for the Divine Eagle UAV, Sharp Sword, and a host of other platforms.
That being said, there are numerous rumors, as well as official statements from SAC itself, that an improved functioning prototype is being pursued.
We cannot make that assertion solely based on a lack of progress. It would be unwise for a company to continue development of a project that its customers remain undecided upon, but that stagnation alone is not indicative of the customer's intentions.
At this point, we simply do not know what the PLAAF/PLANAF's feelings are regarding the FC-31, nor do we know its capabilities well enough to form our own assessment of its prospects. A lack of publicity regarding the FC-31's testing regime is by no means implicit of its rejection by the Chinese armed forces. Additionally, rumors claim that the PLAAF's decision will not come until late 2016.
Yes, at this point, absence of visible progress of the J-31 alone cannot be evidence of slow pace. However, I am comparing the visible progress of the J-31 with other similar programs in China. It is a parallel comparison.
You mentioned the J-11D. Once they had the maiden flight, we began to get consistent info on the progress of the J-11D. Similarly, we knew little of the J-20 until they made the maiden flight. Then we began to get consistent info on its progress. the J-31 made maiden flight long time ago. We all saw the photos. Instead of all the amazing progress seen with other programs, such as the J-20, J-11D, J-10, J-15, J-16, the J-31 is at a standstill.
It's not because of lack of info. We still get photos of the J-31 every once in a while. If you go back a couple page in this very thread, you will find tons of photos of the J-31. The only weird thing is that it's always the same plane sitting, taxing and flying a bit. No change whatsoever.
You cannot use tightening of the security as an excuse because we are comparing similar programs in China. The same level of security should be applied to all programs in China. We also see the SAC taking the J-31, the actual plane and/or scaled models, to airshows. However, we never see the J-20 at any airshows. So if anything, the J-31 actually enjoys looser security than the J-20. In fact, it seems that the SAC is actually advertising the J-31, instead of hiding it. Yet, we see progress of other programs, particularly the similarly sensitive stealth fighter J-20. Nothing with the J-31.
You also cannot use different physical location of SAC vs CAC as an excuse. Someone has mentioned that the SAC is at a more remote location. However, it's not that we cannot get photos. We still get photos of the J-31. Although not as often as the J-20, we still get them, with the J-31 sitting, taxing and flying, with the landing gear down or up, with the weapons bay closed or open. All sorts of configurations. So we can still get info. The only difference between the J-31 and the J-20 is that J-20 keeps evolving and the J-31 is still that same old pathetic self.