Most recently, a 7th prototype of J-20 project (No. 2016) appeared and made its maiden flight on September 18th. It’s been 9 months since the last prototype had come out, so this new prototype is a sign that the program has not hit any major stumbling block and was just going through the next iteration in its development. As a refresher, 2 prototypes (No. 2001 and No. 2002) came out and flew in 2011. They were probably the demonstrators of this program. Over 2 and half years later, the 3rd J-20 prototype (No. 2011) came out and was followed by 3 more prototypes (No. 2012, 2013 and 2015). They had some major redesign and changes compared to the demonstrators. So they should be considered the first pre-production prototypes and were probably produced in the same batch. CAC and CFTE have been testing them since that time. I expect that more J-20 prototypes will be coming out in the next few months, since they seem to be building them in batches on this and past CAC project. Compared to the last batch of J-20s, the most noticeable changes have been on the DSI bump and the engine nacelle. The DSI bump looks to be a little larger and people have speculated that some EW equipment may be installed inside. From the relatively few changes between the batches, one can surmise that the J-20 design is more or less frozen.
Indeed, there have already been speculations that the first production J-20s will come out next year to be tested and evaluated by FTTC. While I think that is certainly possible, I think it is also best to tamper one’s expectations and expect some problems along the way. Every 5th generation projects so far have experienced some bumps along the way. The PAK-FA project had fire on one of its prototypes and still has not flown a new prototype since. IAF have continually complained recent years about the technology and progress of PAK-FA. The F-22 and F-35 projects are far more open, so there were many reports of issues along the way. One would expect J-20 to encounter similar issues along the way even if those reports only come out in the rumour mills of Chinese military forums.
With everything that we can see, I think that CAC has been doing a great job with the J-20 project. At this point, I already consider J-20 project to be ahead of PAK-FA in both the design and timelines. In terms of design and technology, J-20 looks to be better configured for stealth from most profiles vs PAK-FA. The next generation AESA radar and the rest of electronic suite are already been deployed J-10B/C and J-16 compared to lack of such Russians platforms. Even the next generation missiles (like PL-10 and PL-15) seem to be further along in development and deployment than similar Russian systems. PAK-FA only seems to be using a more advanced engine at this phase of testing. Considering that the Russians started to research on 5th gen fighter jet in the 80s and first flew PAK-FA a year earlier than J-20, this does not speak very well of Russia’s aerospace industry.
For the past year or two, I’ve read numerous articles coming out of India that complained about the technology, cost and lack of their work share in the PAK-FA project. Since then, there was a fire on one of the PAK-FA prototypes when they were giving a flight demonstration to Indian delegation and have not shown a new prototype since. There have also been numerous online posts about the build problems and quality issues with those prototypes. Now most recently, I’ve also seen a report where India is thinking of pulling out participation in the development of PAK-FA and just buying them straight out of Russia. They probably realized Russia was unwilling to share its most sensitive secrets so they needed to devote more of their R&D resources on their domestic project MCA. At the same time, it also appears that some in IAF is favouring for purchase of more Rafael and less PAK-FA. There are numerous components of PAK-FA project like stealth and propulsion, which are not up to par with the standard established by F-22. If the leap in technology over Rafael is not big, then it makes all the sense to buy the more of the mature platform. Of course, that could also create a disastrous scenario for IAF if J-20 and FC-31 turn out to be much better than Rafael.
If all goes well, J-20 looks to join service in a couple of years. This version of J-20 will be quite underpowered and have to wait a few years before getting WS-15 engine. That would be the next major change for J-20. It looks like the second demonstrator or first pre-production prototype of FC-31 may be coming out soon. I think most people expect some significant changes vs the first demonstrator. In the recent years, CAC has devoted most of its resources on J-20, whereas other projects like J-10B/C have been a little slow in development. SAC is tasked with the development of numerous flanker variants and UAVs. It may not be able to devote the same amount of resource on FC-31 project, so I would expect the progress on FC-31 to be slower than J-20. Even if FC-31 becomes ready several years after J-20, it may still become available to export market at the same time as PAK-FA (after Russian and Indian orders). So I think FC-31 could capture a good chunk of the non F-35 market.