I did specifically say "all SAC built land based flankers" -- i.e.: excluding J-15s which are carrier based.
C'mon this ain't amateur hour.
I don't know why the testing of the J-16s has already taken such a long time. It is just a knockoff of Su-30MKK with more advanced radar and electronics. This is clearly a testing aircraft with no PLAAF serial number on the tail. Maybe my question should be why did the J-16 took much longer than the J-15s in R&D and fly testing, when both are copies of Su-30s and Su-33s?
No, I think it is quite certain that J-16s have entered serial production (quite a while ago) and likely entered service.
What we see here is almost certainly one of those in service J-16s or a newly mass produced J-16, but lacking its serial. It is common for newly produced or even newly inducted aircraft (especially new types of aircraft) to lack serial numbers to avoid revealing the unit and location they are assigned to (in other words, a form of operational security). In some cases the serial number is simply not yet painted by the manufacturer, and in some cases the serial number is even PSed off by the photographer. Or, the photographer may only release photos of the aircraft with the serial number deliberately obscured by another part of the aircraft. We've seen this in action with J-10Bs as well, much to Deino's chagrin.
As for J-16 being "just a knockoff of the Su-30MKK" -- not quite. Aerodynamically and in some cases structurally it is probably virtually identical to the Su-30MKK. But in terms of avionics, weapons suite, and materials, it should most definitely be considered a new aircraft compared to the Su-30MKK.
With the sort of capabilities that J-16 is meant to bring relative to Su-30MKK, especially in regards to its avionics and its weapons suite, the development cycle length that it experienced is actually quite reasonable. Remember, first flight was supposedly in late 2011, and testing should have completed by late 2013, with mass production and induction commencing shortly thereafter.
As for J-15, it has similar differences relative to Su-33 in regards to avionics, weapons suite, materials, which also hold true (keep in mind China only had a T-10K prototype as an accessible aircraft, no actual production Su-33 like they did with Su-30s). It is also SAC (and China's) first attempt at a carrier based aircraft as well.
So the J-15 development cycle also is quite reasonable, with first flight in mid 2009 and mass production commencing in about late 2012 or early 2013.
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Finally, remember that SAC is currently producing multiple variants of the same aircraft, including J-15s and J-16s, and are shifting their production line from previously only producing J-11Bs and J-11BSs, and are now also prototyping J-11Ds and J-16Ds which will soon enter mass production in a few years as well. In other words, unless they have expanded their production line, then it is reasonable to assume that they are using their previous J-11B/BS production line for both J-15 and J-16 production at the same time, meaning it may be quite possible that we will see relatively lower production of each type compared to previous J-11B/BS production, but if we put actual J-15 and J-16 production together then it will likely equate to similar numbers to what J-11B/BS production was in previous years.
