x post from CDF
So, now that it seems to be increasingly likely that FC-31 will be the basis of the carrier based 5th gen fighter to emerge in the next year or so, I think now would be a good time to start speculating how the project may run.
The interesting thing about the carrier 5th gen project (sure let's call it J-XY), is that SAC have been flying a pair of full size stealthy tech demonstrators for a while now, with the first TD flying for over half a decade. These airframdes obviously are not TDs that for carrier related studies, but they certainly are certainly good generic 5th gen fighter TDs. In terms of size and in terms of being aerodynamically representative of the J-XY that will emerge, I think they are far closer to the likes of J-20 prototypes 2001 and 2002, or the YF-22 airframes, than the Japanese X-2 for example.
In other words, when considering the potential timeframe of development for the J-XY, I believe that it would be fair to cut down a few years for the extensive R&D and data that would've been collected from the two FC-31 TDs.
However, there are additional complications that may lengthen the development timeframe of the aircraft, namely being a carrier based fighter. While SAC has had experience with carrier based fighters in developing J-15 and continuing to develop J-15 variants, combining the demands of a carrierborne aircraft with a stealthy 5th generation aircraft will nevertheless be demanding.
... yet on the other hand, it goes without saying that many of the subsuppliers for 5th gen aircraft (materials, avionics, etc) will likely be far far more mature now than they were over 8 years ago when J-20 s/n 2001 took off for the first time, meaning the products they can offer should be much more directly applicable on prototypes.
So, I have a pair of underlying assumptions:
A: that the first J-XY prototype we see next year will be a "prototype" akin to the J-20 201X aircraft, where subsequent prototypes will not see significant modifications. This can be judged based on whether it has certain features like folding wings/tails, nose gear catapult bar, tail hook, certain specific sensors (like chin EO IRST etc) -- some of those such as catapult bar and tail hook might be added onto the first prototype later, or it might be only present on the second J-XY prototype, however it is important that it must be easily "added on" to qualify for being a "prototype" rather than "tech demo"
B: that J-XY will primarily be a carrier based fighter for PLANAF primarily, and that it may evolve into a land based fighter eventually for PLAAF (with the requisite modifications) however that would be some years down the line.
Using those two assumptions, I make three projections:
-Best case, 3-4 years: where SAC was able to take significant data and info from the two FC-31 TDs, and combine it with experience in developing J-15, and further combine that with AVIC's overall experience in developing J-20, to significantly mitigate risks and develop the aircraft more or less without hiccups, resulting in an overall development timeframe similar to that of the J-20 201X prototypes to when J-20 was introduced. That is to say, a ~4 year development time between the first prototype flying and initially being introduced (similar to J-20 -- s/n 2011 flew in early 2014, and entered service in late 2017 with initial combat capable units receiving their first aircraft earlier this year). If J-XY makes its maiden flight in late 2019, then it would begin to be introduced in late 2023 or early 2024, right when 003 would begin to enter service.
-Moderate case, 5-6 years: similar to the above, but where various unforeseen hiccups happen, causing some delays to happen for various reasons. Likely due to complexities of combining 5th gen features with demands of carrier operations. May also be complicated by PLAN demands for "new" 5th gen features that were not present on the original J-20 (a result of both technological complexity and minor programme management difficulties). In this case, the aircraft would enter service around 2025, 2026, after 003 would've been in service for a few years.
-Worst case, 8-10 years: this is very much F-35 levels of delay, and would be a result of SAC incompetence, or significant mismatch between various suppliers, or unrealistic programme demands, or additional technological demands, industry incompetence, concurrency, and so on, or a mixture. Needless to say, such an aircraft would only enter service in the late 2020s or even early 2030s.