With a combat radius of 1000 to 1500km, 300 J-20 would be enough to defend China. You don't need to constantly patrol every single inch of territory, and most critical points are covered by 300+ km range SAM anyway.
how do you get that kind of combat radius while carrying payload and no fuel tank? Do you have an idea how fast combat radius shrinks as soon as you start adding additional weight? Where are these 300 km range SAMs? Show me. Do you understand how vulnerable the country would be if just reliant on SAMs and how effective modern air forces are at SEAD missions? You need both fighter jet and SAMs + many other things to defend air space.
With 300+ J-20, I really question whether China will need any other fighter. Instead, it should shift its focus toward a heavy stealth fighter-bomber, like T-50.
J-20 is already in flight testing. I'm sure we will see it enter service in 3 to 5 years. During those 3 to 5 years, PLAAF can keep making J-11B and J-10A with domestic engines.
I need to repeat myself again, China will not be able to put J-20 in service in 3 to 5 years. China does not have the money to buy and maintain large number of 4th gen plane until well into next century.
As for total number, you might only need 300 J-20, but you need a lot more cheaper planes to fill up the number. Those J-20s that might come only by 2030 are not going to be able to fly at all times, so you still need many regiments around the country.
Most importantly, PLAAF will always keep many more regiments around than needed. Whether you think it's needed or not, they will do it. J-10's newer variants will be frontline fighter jets until J-20 come around. Even when J-20 come around, they will still be the lo end of the hi-lo combo. On top of that, PLAAF does not like to disband regiments for many reasons. They are going to need an even cheaper option to replace the vast number of J-7 options around.
So this will probably hurt you, but something cheaper like JF-17 or L-15 will also be procured on top of J-10s to replace those J-7 regiments. Whether you like it or not, that will happen.
Even if 4th generation fighters are still needed past 2013-2015 when China starts making J-20, the best solution would be J-11B and J-11BS, not J-10B. China nowadays needs fighters that are leggy. This is the chief shortcoming of J-10. China should step beyond the era of short range point defense fighters.
Heavy, long range, strategic, multirole and stealthy should be where PLAAF focuses on once J-20 enters service.
Do you see how much problem they are having with J-11B/S production right now? Even if SAC is going at its max rate, it would have to produce naval flankers for PLANAF and J-11BS for PLAAF. Does it even have any capacity left to produce more units to replace the air defense regiments? On top of that, J-11s are far more expensive than J-10s, which are still more than a match for J-11 in air superiority missions.
You need to get a reality check.
There is no reason why China's air force will be primarily defense oriented. Who is going to push a war into China's mainland? Nobody. Instead, future wars will be fought over the first island chain or central asia or the subcontinent! J-10's are by all accounts superior fighters to J-11, but J-11B and J-11BS have longer legs.
China's priority now (starting from 2008 perhaps) is power projection -- by air, land, sea and space.
Do you realize the amount of threat that China still faces from resurgent RuAF, IAF, ROKAF and JASDF? On top of that, there is always the constant non-ending issue of Taiwan war scenario. J-11s do have longer legs, but what are you going to do with 200 km extra in range? With 3 fuel tanks + 2 PL-8 + 2 PL-12, J-10 has a combat radius of over 1000 km. With the weight savings on J-10B, its range is only going to increase. Its range is not too far away from what J-11 would have with its typical air superiority configuration.
Either way, neither are going to project to subcontinent. The only way it would be able to do that will be through aircraft carrier. That's why SAC will be dedicated to producing J-15s bye 2015.
i see 8 bombs there. one is mostly hidden by the landing gear so it's hard to spot.
but ive got another question - what size class are those bombs? 125 kg?
I think those should be 250 kg. Don't think China have any lighter dumb bombs.
I think I read your blog. Good one... But I think the main reason for China to induct anything is to achieve low price but majorly to be able to make the whole plane... I agree with J10 having more potential but having a cheap (maybe for china the lowest tech If you have J10-J11-Jxx) replacement for J7, this would do just fine for the next decade. In some countries the pilots make hours in cheaper planes... For China this could be a cheaper plane.