@Deino
According to multiple experienced PLAAF ORBAT-watchers, the 78AXA-series of PLAAF units work like this:
- 78AXA units do not follow the "78X - 611" scheme. That means there are no such things as the 170th-177th brigades. I think AMan's post about 788 - 722 is correct.
- 78X1X, 78X2X, 78X3X are Cangzhou regimental-level units. Although they are regimental units, they fly so many aircraft that their total number is far larger than a normal division. Their mission is two-fold; combat and advanced training. The pilots that are assigned to them are the best of the PLAAF.
- 78X6X is Dingxin's oldest unit. Their mission is testing and experimenting. They fly a large assortment of aircraft from J-7s to J-11Bs, to transport aircraft. They are responsible for evaluating weapon systems. The trialling the PL-15 spotted a few years ago belonged to this unit.
- 78X7X is a new unit formed in 2014. Their mission is evaluating new equipment and writing the manual for the rest of the PLAAF's pilots. The 90th PLA Anniversary parade's aircraft were mostly from this unit. New aircraft are sent to this unit for evaluation before further proliferation. Their mission used to be handled by Cangzhou's units.
- 78X8X is a new unit formed in 2014. This is the PLAAF's new dedicated OPFOR unit. They replace Cangzhou's old OPFOR unit that was the size of a "dadui" (8 aircraft?). This unit is a brigade-level unit, far larger than the old OPFOR unit. Their designation is the "PLAAF 66th Brigade", not 177th Brigade. They supposedly fly of aircraft. So far, aircraft no. 17, 21, 25, 26, and 32 have been spotted.
- 78X9X is a UAV training unit, possibly also a combat unit. They were featured in a few CCTV-7 broadcasts. They are not the same unit as the one that was featured in the 2015 Parade.
Me again with one issue I just noticed right that moment: If these brigades follow indeed a system of 78x - 722, then it does not fit to the J-20's and J-16s with 78x7x numbers, which are said to be from the 176th (old system) or 66th (new system) brigade???
So wouldn't be a "78X - 721" scheme be much better?
Even more at least by a look thru my collection I did not find any 78x8x-serial numbered aircraft?
Anyone else with some more info?
Best,
Deino