Running along, for the sake of fun, with the rumor of 30 J20 & 80 flanker production this year, getting to 30 produced J20 in 2020 isn't that big of a deal. Even if there were not any pressure from the possible cold war arms race, the rate is fairly comparable to the US programs during the times where there were no such imminent threats.
F-35 first flew at the very end of 2006. First LRIP airframe flight was in february 2011 and deliveries shortly after that moment roughly 4 years later.
during that 5th year since the first flight of the prototype - 9 LRIP airframes were delivered.
6th year saw that jump to 29 airframes delivered.
7th year saw that jump to 35 airframes delivered.
F-22 first flew in 1997. in its third year since then, later two LRIP planes were made. Six more in the fourth year. 10 more in the fifth year and so on. That was a different time though, when there were zero threats and whole F-22 program was seen by many as pointless.
In late 1990s, when 339 F-22s were planned in total, the production plans were: first LRIP starts (not sure if delivered?) in 1999, and by 2004 the rate would have been 36 per year. Of course then further funding cuts came... so six years from first deliveries to 36 per year.
The question of J20 being produced at 30 per year is thus just one of need. If the need is there, and if the political decision is there, the funding will be there as well, and the production bottlenecks are not something unsolvable.
I assume here the first LRIP J20s indeed flew in 2016 (roughly 4 years from now). With the first J20 prototype flying in 2011 that's 9 years from now. At that point, 9 years from the first prototype flight - F35 was at 45 airframes per year. And F-22 would have, based on the prior plans, hit its production plateau of 36 per year two years earlier.
So 30 J20 per year is absolutely within expected range. If not even somewhat weaker result than possibly expected, given the whole Cold War vibe going on.
Also, the fact that rumor did not mention J10 doesn't have to mean anything. Just because something is not mention, doesn't mean it's not there. Actually, I would be absolutely floored if I learned that J10 production ceased, or was even halved. So I do expect J10 production to be chugging along at 40-ish or so airframes per year, that we've seen it do in the recent years.
On the question of flankers' rate (or any other plane for that matter), all we had all these decades is:
1. images of production/batch numbers on airframes. So watching those over a period of time gave us a sense of a production rate.
2. and, as a confirmation coming years later, images of serial numbers and images from various units. So we knew how many new units got new planes within a span of, say, 10 years.
And those two methods worked pretty well for years and years. We do believe we got some fairly precise figures both for J10 and for flankers. Until last two years or so, when the images slowed to a trickle. Insufficient to really do a good track.
so, is it possible that during those two years flanker production skyrocketed? Yes, it's possible. But until we do get some photographic evidence, it's impossible to conclude anything either way. It would be quite a shift, though. As methods used by most people following the new photographs since late 1990s have been quite good at concluding that SAC's own facilities never made more than a regiment, regiment and a half worth of flankers per year. All the way to late 2010s.
The other question is one of requirements. Up until the year 2010 or so, PLAAF and PLANAF combined seemed to have been content with upkeeping a force of roughly 2000 combat planes, judgning on the overall production rate.
During the last 10 yeasr, the production rates have crept upwards. From 80ish to 100 planes per year, overall. And today's flankers and J10s are also possibly expected to fly for longer, EVEN WITH the pilot training hour requirements possibly going up to nearly 100% compare to what they were 20 years ago.
So it may be that chinese air forces have already decided to increase their overall numbers past 2000 airfames.
But hiking up production by 80 additional frames (30 flankers in the past compared to 80 flankers now) after the j20 additon came a few years ago is suddenly suggesting not just 100 combat planes made per year but closer to 160.
That's over three quarters of whole chinese air forces produced in just a single decade.
There's not a lot of J8s to be replaced anymore. Perhaps 150 or so in total, if that. (not counting the Recon variants, as those are likely to be replaced by non-combat aircraft)
Original Su27sk seem to have been retired completely, with perhaps some UBKs left around. Those too, even if they exist, are likely only a dozen or two, dispersed around various units.
J11As are quite newer, being between 21 years and 16 years old now. Those were airframes with strengthened airframes too, compared to Soviet ones, so perhaps some further life could be extracted from those airframes. While they may start getting retired during the next 5 years, I don't believe we'll see them all gone until the year 2030.
Su-30s from Russia will likely be retired in a similar timeframe, perhaps a few years later, if their even more strengthened airframes allow.
Original JH7s are now roughly 20-25 years old and will likely start to see retirement within the next few years; certainly by the end of this decade.
But all those mentioned are just 410 or so airframes, combined. Assuming J10 production replaces exclusively J7s, there's 60 J16 and 30 J20 to replace those 260 airframes. Literally just 4 and a half years worth of production is enough to do that.
Then there are the J11Bs but those are still very new. And are being upgraded, so it's evident China means to keep them for a longer time still. I don't think we'd see even the earliest J11Bs replaced for another dozen years or so. JH7As might fare slightly worse but still 10 years before first retirement is likely. They can do their stand off missile truck mission quite well even if they're old tech. I do see PLAAF getting rid of them sooner than PLANAF.
So that's another 400+ airframes, to be retired from 2030 to 2040.
Of course, ALL those airframes could be retired sooner and simply sold as second hand planes. But in a cold war environment I don't see that as likely. Both the US and Soviets kept their hands on old planes during 1980s, like the F4s and even Mig21s for the Soviets, even though they had newer toys.
Sustaining a jump in production of 160 combat planes for a few years, just to go down soon thereafter is senseless. Either that production is going to stay, as the cold war is perceived as a real threat - or if there is no perception of threat then there'd be no hike in production at all.
So... either the rumor is just some mistranslation (or is not correct) or we will see a prolonged, decade long at least, effort to increase the size of chinese air forces. Which is then likely to stay at the new size of possibly 3000+ combat airframes. And since somehow I don't see US not reacting to such a build up and since US would be likely to increase its arsenal further - there's really no end in sight when it comes to increases. We might be looking at 4000 or higher numbers for chinese air forces by 2050 or so. Wild speculation, i know. But so is everything about the initial rumor.
