There are folks who are trying to sift through all the crap that gets posted on Chinese SM and trying to create some form of accurate picture of events, and others who are just bad and fanbois with no real knowledge or analytical chops. Best to use the evidence that appears to be released by China and then work backwards and ignore all the bad takes that may originate from random folks on twitter or elsewhere. PL-21 may well be designed for ultra long range but we simply don't know because there is no physical evidence that would allow an assessment.
We have seen the PL-12, PL-15 and PL-X. Those three generally tend to support some of the more logical claims of iterative improvement on PL-15 especially if they have gone for a two data link, and a dual pulse motor. That should result in considerable range increase (over PL-12) and may well put it in the 200 km class against certain targets and intercept trajectories.
PL-X again appears to be a fairly large missile so very easy to guess that. it is designed to be the main weapon to execute ultra long range intercepts against high value non maneuvering targets. Given the target set, you can justify the larger size and weight. It is rumored to be 18 ft in length, and a larger diameter to the PL-12 and PL-15 series. Again, not out of the realm of possibility. The USN was also seen testing an unknown (though appears to be a booster-less SM-2/6 which is a 13.5 inch diameter missile relative to the 7 inch AMRAAM) ultra long range interceptor back in 2018 and the effort (this was captured then in broad daylight) was likely ongoing for a number of years prior to this. China too has a fairly substantial number of large RCS bombers, tankers, AEW etc etc so this would be a logical thing for the USN to work on as it develops a Counter-A2AD capability.
The Weekly Debrief: Air-Launched, SM-6-Like Missile Exposed In New Test Photo
Rakesh wrote:I am not providing a link to this photo, because it comes from a NaPaki military forum.
This could be correct or though I suspect that 400 km is probably in the 300-400 km class. The PL-X fits that bill. PL-15 is a 150-200 km class weapon if it does indeed leverage two-way data-link, and a dual pulse motor. PL-21 could be PL-X or it could be a completely different system. I would suspect that it is an iterative improvement over the PL-15 but that is just a guess.
Rest on the PL-20, PL-XX, PL-21 et al is just a big unknown at this point.
But all the focus on missile kinematics ignores that on net-centric warfare, or ROE's and how PLA and PLAAF will collaborate on these type of missions. That's a bigger puzzle to crack. On the USN example, I cited earlier, we can go back to 2 decades of investment in creating a very long range beyond-line of sight integrated fire-control network. This manifests in a full fire-control level composite track capability leveraging AEGIS ships, E-2D's, EA-18G's, and F-35C's (and Blk III F/A-18s in the near term). This then coupled with launched and engage on remote capability fielded on missile defense side. And there was CEC even before that which though not on a common FC loop was still something beyond sharing overlays over data-link..We also know that they (DARPA and USAF) are experimenting with 100 Gb/s RF backbone so all that supports much longer intercept ranges where you are reasonably confident (though nothing is ever 100%) that you don't shoot down an airliner or your own aircraft and that you can create a viable kill chain that is somewhat self-healing (using mesh networks and distributed LOS and BLOS assets). I am not sure the Chinese concept of air-power is there yet. Seems still an Army, and artillery centric joint force which would handicap such concepts from emerging and being fully fleshed out prior to fielding. Thats a more interesting and worthy of research topic and much harder than fielding larger diameter weapons or new types of iterative seekers.