I don't have a PLA blog, but if I did, this would be my write up on how the Myanmar jet managed to enter Chinese airspace and drop bombs unopposed:
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Some comment threads for articles on this piece of news are questioning just how capable the PLA actually is if even a measley jet from the Burmese air force could enter Chinese air space and bomb Chinese territory.
Those observations, while justified, miss a few important pieces of information.
First, the actual site of the bombing was very close to the border between China and Burma. Some news outlets have described it as Lingcang city, which on the map is 100km from the border, but it actually occurred in Gengma county, which is the pink piece of land within the yellow in the map below. As we can see, it is quite close to the border but even then it is a big piece of land.
Second, the geography and more importantly, the dispersal of PLA air bases and air defenses on a national level means it actually wouldn't be very difficult for a low flying Burmese jet to enter that airspace and proceed for some kilometers without being challenged. The area is hilly cluttered with forest, limiting the utility of ground based radar for lower altitude targets. And despite maintaining one of the largest AEW&C fleets among the world's air forces, the PLA has sensibly based them mostly on the eastern side of the country facing the biggest threats to the PRC; Taiwan, Japan, and the US out to sea. The southwest of inland China until now has generally not been considered a very high profile border to be monitored, compared to the East China Sea, South China Sea, Yellow Sea, border with North Korea, border with India, etc.
The closest airbases to the area according to scramble are Luliang and Mengzi, but remain quite far away even from Lingcang -- Luliang is 380km away, while Mengzi is slightly closer at 330 km away Accordingly to scramble, Luliang operates a J-10 regiment and a J-7 regiment, whereas Mengzi only operates a J-7 regiment.
I would expect patrols of the border to have been divided between J-10s and J-7s. J-10s naturally have longer range, endurance, and much more capable avionics and weapons, but at the same time their numbers are limited in the area and placing all the burden onto a single regiment would be a poor operational decision.
It is easy to envision a scenario where a Myanmar Q-5, flying at low altitude above the hills and clutter of trees manages to elude the limited ground based radar coverage as well as the aged and short range radar of any J-7s patrolling near Lingcang, and manages to slip past the border, pop in a dozen or two kilometers into China's soil and conduct a bombing run before speeding out of there.
It is worth noting that the PLAAF had supposedly been conducting patrol operations for some days prior to this, and it is likely that there had been previous encounters where Myanmar aircraft were successfully intercepted and warded away, but two instances of bad luck and limited equipment due to limited budget allowed such incursions to occur.
Fundamentally this incident likely resulted from insufficient aircraft and equipment positioned in the location close to the Myanmar border. The incursion would most likely have not occurred had all regiments been made up of longer ranged fighters like J-10s and flankers, supported by AEW&C, and more advanced ground based radar and even SAMs.
These limitations can only be solved through time and budget, because despite China's large budget and large number of modern fighters and AEW&C, they still don't have enough to fully secure all their borders with modern equipment. The newest equipment and capabilities tend to go where they are needed -- facing east. This leaves inland regions and areas facing lesser threats relatively underarmed. China is simply too big with too many borders, for their limited budget to fully arm every military unit to a modern standard.
That isn't to say the PLA as a whole is not combat capable, it just means that some units of the PLA are far more capable than other units which may be forced to make do with older equipment due to their geography, and may only receive support from other more modern units when they're deployed based on transient need. We can see this with photos of PLA deploying more troops, medium range SAMs, advanced surveillance radars, and even rocket artillery closer to the Myanmar border now that the need has presented itself. News that the PLAAF has expanded air patrols near the border may also indicate increased numbers of modern fighters supplementing the local regiments, possibly even with other air elements such as AEW&C although this is merely speculation.
In hindsight, the biggest mistake the PLA has made in the last month since fighting in Myanmar intensified, was not supplementing the local air and army units with more modern elements as a precautionary bulwark. They've made the right decision now, but it is too little too late for those four innocent villagers working in their sugarcane field.
