There are many theories about Project Azm. Let me summarize them here:
Project Azm as J-31 / J-35 Version.
The major supporters of this theory are Bilal Khan of Quwa and Mastan Khan. The belief is that Pakistan will choose a variant of the Chinese 5th generation aircraft, the J-31 for its own Project Azm. The proponents note that Pakistan has severe resource and technical constraints to develop a truly indigenous development.
These proponents are unable to convincingly answer why PAF officials have defined project Azm as a first locally developed design. Their counter that PAF has asked for collaboration doesn't fully make sense - as there can be collaboration on subsystems, wihthout the project losing its characteristic as a clean sheet Pakistani design.
Project Azm as an Clean Sheet Pakistani Design
Myself and others have put forward the view that Project Azm is an indigenous design, noting that if Azm was a J-35 derivative, it would be a step back for Pakistan, and would directly contradict what PAF has said about the project. It would also not make sense to make primary investments, like Aviation city and the various research and development organizations, that just are not needed if Project Azm were a J-35 customized for PAF.
What will Project Azm Look Like?
Assuming Project Azm is a clean sheet design, there are various possibilities for the basic layout and capability level for Project Azm:
1. A J-20 type with twin WS-10 / WS-15 engines and a canard delta
2. A Single WS-10 / WS-15 engine with a delta canard layout
3. A Twin heavy WS-10 / 15 with a conventional layout
4. A single WS-10 / WS-15 engine with conventional layout
5. A twin WS-13 / RD-93 delta canard
6. A single WS-13 / RD-93 delta canard
7. A twin WS-13 / RD-93 conventional layout
8. A single WS-13/ RD-93 conventional layout
9. Something completely different, perhaps like a YF-23, similar to the art found on the PAF C-130 (a YF-23 with canards)
The twin heavy engines are not realistic, as PAF does not have a long range / heavy payload requirement. The single WS-13 / RD-93 are also not realistic, as they would not provide enough thrust for a 5th generation aircraft. This leaves either a single WS-10 / WS-15 engine, or a twin RD-93 / WS-13 engine option, realistically.
Another key problem is the development of an FCS. Some individuals, such as JamD, have suggested that Pakistan does not have the capability or wherewithal to develop an independent FCS. My point of view is that the PAF has the JF-17 FCS. Even if China developed it, the Chinese would not withhold this FCS. Pak would definitely be able to to outsource this FCS from China, giving them adequate compensation.
If Pakistan uses the FCS developed for the JF-17 Block 3, they are limited to a conventional layout option. Meaning, something like a JF-17 / F-16 / F-15. This would also be true if they utilize a Turkish FCS.
This brings our options down to (4) and (7) to most likely option for PAF. Meaning a conventional layout with either a twin RD-93 or a single WS-10 / WS-15.
Now finally, Chak Bamu, another poster on the internet, with a solid track record and some access to the Pakistani R&D community, says he "saw" the Azm. Obviously, there may not actually be a flying prototype right now, so he most likely saw a wind tunnel model. He was clearly able to say that it is in fact a clean sheet design, and not a derivative of the J-35.
Had it been a twin engine conventional layout with RD-93s, the design would have been close / similar to J-35 and would not have allowed Chak Bamu to clearly state that the design was a clean sheet design. The conclusion, therefore, is that the design is in fact, in all probability, a conventional layout with a single WS-10 / WS-15.
The benefit of this layout, if in fact my estimate is correct, is that the engine would be common to the J-10 and J-15s . Allowing Pakistan the capacity to easily simplify the WS-10 / WS-15 to its overall warfighting strategy, should they buy those aircraft.
The CAS said the ASR is twin-engine, so if we're following what the PAF says, then we should cast aside theories about it being single engine. These are the words of the CAS, verbatim: “We hope it will be a twin-engine single-seater, boasting the likes of super cruise and laser weapons” (Jane's May 2019).
Second, in the same interview, the CAS said that the PAF will be open to a consortium or partnership. We can read into this in a million ways, but Occam's Razor (itself based on other publicly available info, e.g., the Turks inviting Pakistan to the TF-X, or AVIC offering the FC-31 for export customers) means the PAF is likely looking at joining another design/project. Interestingly, the two potential options (TF-X, FC-31) match the ASR.
Yes, we can say, "well they can also collaborate on subsystems, etc" or leverage overseas inputs. This is fair, but that route would not meet the PAF's aggressive timelines.
Third, the PAF's timeline -- i.e., induction starting from the 2030s -- precludes clean-sheet development from scratch. This is a rational assessment based on observing the facts -- it'd take a mature aerospace power 10-15 years to design, tech demo, prototype, and complete a serviceable, production-ready fighter. Pakistan isn't that, so it's not going to meet the CAS' expected timeframe, which rationally speaking, leaves us with FC-31 or TF-X.
However, of the FC-31 and TF-X, only one of them went through a successful demonstrator stage. It's FC-31. If the PAF wants to induct a FGFA by the 2030s, there's no other option.
Now, does this preclude a totally in-house fighter? Of course not. It simply means that the PAF will need to de-link its 2030s FGFA requirement from AZM. In turn, it can pursue AZM without pressing timelines or a fiscal crunch (as it can distribute funding across many more years). This would translate over into a 5+ or 6th-gen fighter program.
What's the evidence for de-linking AZM from the 2030 FGFA? Well, the previous CAS -- ACM Sohail Aman -- said that the PAF is thinking about "beyond 5th-gen." The current CAS also said (in 2018) that the PAF has a 'Vision 2047' -- and eliminating dependencies on overseas suppliers is a goal under that framework. So, we have 2 CAS' thinking
very long-term, and a vision for turnkey independence exists. But we can't assume the PAF will make that leap in one go in an aggressive timeline.