plawolf
Lieutenant General
Importance of air power has been rising for decades, that much is clear. And with the end of the Cold war many nations cut their air forces in half or even more. Chinese air forces included. Sure, quality of training and planes skyrocketed in the last 20 or so years but it seems chinese air forces are happy with the current 1800-ish to 2000-ish tactical combat aircraft. The number of j-7 and other older planes left to be replaced is such that the production levels of the last decade can't really be counted upon to increase the inventories further than the mentioned figure.
And yet... should the chinese air forces be larger? Of course, it depends on long term strategic requirements and possible/probable threats. But I believe some long term goal should be a considerably larger figure than today's inventories and today's orbat. Specifically, some notional 2040 roster might be well advised to have as many as 3000 tactical combat planes. That figure is not taken out of thin air. It is a product of projected combined enemy fleets. Several countries in China's neighborhood can plausibly make an alliance in a future war. And even one country that's not technically a neighbor but can project considerable power abroad. Looking at the number of possible bases and aircraft availability over the long distances (half the world away) i would say China needs to counter a possible combined force of some 2800 (700+1000+300+350+450) enemy planes, most of which are projected to be technologically as capable as then-year average chinese combat plane.
It is not just about defence. If it was just about that, a smaller figure would suffice. Once a country is only defending it usually means the war is lost. Active defense, including regular offensive action is required, which requires larger number of planes to make up for more complex strike packages and longer distances involved, less sorties per plane achieved and so on.
Realistically though, even if an increase is on the cards, a 50% increase in mere quarter of a century seems impossible, short of a cold war style arms race, which would then surely mean the opponents would be increasing their fleets as well.
3000+ combat aircraft seems excessive (assuming you are only counting manned assets, if you are also counting UAVs and UCAVs, then that number could be a lot higher). But for clarity, all my comments and analysis will be directed at manned aircraft only.
If anything, I predict the Chinese air force numbers to further decrease by 2040.
China does not, and will not make the mistakes of the USSR and bankrupt their economy trying to win an arms race.
I question where you got your 2800 enemy aircraft number from, but even that kind of misses the point, ironically - bases and offensive capabilities.
Anyone country close enough to host enemy tac air to be fielded against mainland targets will themselves be within range of significant Chinese offensive assets of all sorts, from cruise missiles to ballistic missiles to manned and unmanned strikers and bombers.
There are only two or three countries and territories close enough to China to be able to offer up a meaningful number of bases to be used against China, with one or two island bases that could potentially be called upon as well.
But all of those countries and bases will be amply covered by Chinese strike options, which would make air operations from those bases problematic at best, and suicidal at worst.
Similarly, even today hostile carriers will have a hard and dangerous time trying to conduct offensive ops within the combat radius of their naval fighters. But 2040, the situation is likely to get worse not better for them, far worse.
So, a coalition of potential enemies may have 2800+ combat aircraft available to be used against China, but they do not have the bases from which to operate so many aircraft from, and any bases and assets they do have which can launch air power against China will be the subject of intensive attack, thus the number of fighters those bases could deploy and keep alive are going to be significantly lower than that theoretical maximum.
You are also not fully factoring in China's biggest strength - its industrial strength.
In any scenario where China is facing attack from a coalition of enemies, we are basically looking at a total war situation at best, and WWIII more likely. Either way, its not a war that will end quickly.
Assuming everyone has the sense to hold off on the nukes, China's strategy in such a situation would be to largely hold with its existing forces while it turns its enormous manufacturing capacity towards the manufacture of war goods.
The longer China can hold, the more the odds shift in their favour. Once a tipping point has been reach, China will go on the offensive and basically steamroll all opposition much like how the US fought WWII.
As such, China is far more interested in maintaining the manufacturing capacity over having a huge standing force. This would favour a slow but steady acquisition policy to keep factories running for the majority of the life of key combat aircraft, which would be good at keeping force levels more or less at present levels by matching production rates of new aircraft with the pace of retirement for older types,.