J-31 possibly being tested & evaluated in Pakistan

[Army research]

What about the production of the prototype airframe itself?

That is gonna start as soon as blk3 production ends , making plane body is not hard, it's the sensor fusion and making high quality electronics which is hard and ofc waiting for engine , no point in making underpowered plane

so you are privy to a top secret n ever seen before fifth generation fighter project called AZM which is so far in development that you claim it looks like nothing of the above .

BY THE WAY im assuming here...……. this is not a concept drawing but a model of a fighter designd for winfd tunnel testing A complete programme with modern super cruise engines and crystal blade tech . full fbw compsite airframes , complete cockpit and sensor fusion and AESA radars development programmes in progess.

AND this is happening in PAKISTAN with assistance from CHINA

FUNDING from Pakistan & China .

WELL THIS must have been going on for years SINCE it takes two decades for huge aerospace giants like EADS or Dassult or Lockheed to develop new platforms.

And generally people in forums do not have privy info on these.

" you understand why im smiling and shaking my head"

it seems farfetched

IN MY EYES AZM exists BUT is nothing more than J31 .

CHINA has no third fifth gen project

Brother,
The project has been going on for years ,
I've already outlined everything in my post,
I was shocked too when I was able to learn about this and it all has already been said publicly by ex air chief aman but people didn't believe it
I was just able to meet engineers working on the project and had lengthy discussions with them,
I understand why you don't believe it trust me I grilled those engineers when they said it's going to be really indigenous, I said it's probably just J31 , then he confirmed that no it's a clean sheet design and I was shocked

 

[Basel]

So you're saying the production of the TD/prototypes have already started?



So Pakistani airframe design and FBW along with Chinese engines and avionics?



I don't know what you mean by backbone. If you are referring to it being in small numbers, then the project won't be viable. You will have to induct at least 5-6 squadrons, if not more.

You had MiG-29 & M2Ks before MKI but backbone was Mig-21.

 

[randomradio]

That is gonna start as soon as blk3 production ends , making plane body is not hard, it's the sensor fusion and making high quality electronics which is hard and ofc waiting for engine , no point in making underpowered plane

Okay, so production can start only after 2022 or beyond, depending on when the Block 3 ends. So when that Quwa article said "5 years away from production", it was referring to the first TD/prototype.

Anyway, the airframe itself is not the problem, the FBW will be. You will have to settle on an airframe design and engine first, even a preliminary engine is enough, and then design the FBW around it. That's the difficult part.

You had MiG-29 & M2Ks before MKI but backbone was Mig-21.

Yeah, but Mig-29 and M-2000 were built in the hundreds in the USSR and France. We only bought some of those from their factories.

It's about making the production viable for Project Azm. If Azm is an indigenous clean sheet design, then you have no choice but to make it the "backbone" by building at least 100-150 jets.

 

[MastanKhan]

I understand why you don't believe it trust me I grilled those engineers when they said it's going to be really indigenous, I said it's probably just J31 , then he confirmed that no it's a clean sheet design and I was shocked

Hi,

The question should have been---why is it an indigenous design---why---what is the reason behind it---what is the engineering base behind it to have own design rather than the already existing J31---.

How is it that Pakistan can afford to experiment when the enemy is inducting aircraft after an aircraft---?

This tantamounts to treason against the state---.

Hasn't the Paf learnt from JF17 that such projects run 10-15 years behind with just one hiccup---.

It looks like the Paf has bigger egos than their brains---.

It is more like a di-ck measuring contest---.

 

[CriticalThought]

Hi,

The question should have been---why is it an indigenous design---why---what is the reason behind it---what is the engineering base behind it to have own design rather than the already existing J31---.

How is it that Pakistan can afford to experiment when the enemy is inducting aircraft after an aircraft---?

This tantamounts to treason against the state---.

Hasn't the Paf learnt from JF17 that such projects run 10-15 years behind with just one hiccup---.

It looks like the Paf has bigger egos than their brains---.

It is more like a di-ck measuring contest---.

Traitors are people like you, always ready with advice that makes Pakistan ever more dependent on foreign technology and in danger of sanctions.

Given the cost of modern aircraft, one point is evident: manufacturers will fleece you dry if you want top of the line technology. Accoess to top end technology has become a rich persons' club - you pay through your nose to play.

In this backdrop, hats off to our top leadership for their visionary thinking. If we don't start now, then for ever more we will be dependent on little morsels thrown by others. Alhamdulillah this is our first step towards becoming self-sufficient. May Allah Help Pakistan in overcoming it's enemies and upholding His Commands throughout the world. Aameen.

 

[ACE OF THE AIR]

The question should have been---why is it an indigenous design---why---what is the reason behind it---what is the engineering base behind it to have own design rather than the already existing J31---.

Hi,
You are asking those reasons that you already know. Please read your own countries news papers and you would find the answers.

1) USA will never allow Pakistan to have top end fighter aircraft even if we pay 1000 times over the price it is being offered at.

2) UN is a victors club of WW2 hence they can not go against them. Impose sanctions on any sale of this technology by third parties i.e EU, UK, Canada, South Korea, Turkey, Russia and China. Unless one of these countries Russia, UK, France or China uses its vote against. Most likely China is the only country that would use this right but limitations would remain as not all the relevant technology is available.

3) Some how Pakistan is able to acquire these aircraft from other countries then any modifications, enhancements, upgrades etc. will still require permissions and hefty payments.

4) The most important is younger generation that will get to experience in this field will be leaving the country. In the near future Muslim engineers, doctors etc will become targets of hostilities as it has already started. Any crime that takes place is first looked upon with religion or ethnicity.

5) The design of J-31 prototype 001 is not up to the standard. Working on that would not attain much because most of its improvements have already been looked upon by and adopted in the new prototype.

Hasn't the Paf learnt from JF17 that such projects run 10-15 years behind with just one hiccup---.

Yes.... She has learnt.
Do not procure what is not going to be produced and inducted in numbers otherwise the costs would remain very high.

This is a harsh reality.

 

[Cookie Monster]

I had a couple of questions for the project director of project Azm but unfortunately, his seminar got postponed.
Currently, we are at initial stage for such an ambitious plan. We are still developing human resources for it. With relatively lack of funds and a bit late start, I am not much optimistic. We most probably still won't develop engine etc which are critical components of self sufficiency whenever the Fifth gen aircraft operationalizes. I wonder what is the definition of indigenous?
Currently, we are solo and only have an aircraft design on the paper which too was rejected.

I don't think Pak can go alone for such an ambitious project. China's help would be a definite requirement if Pak is to be successful in developing its 5th gen platform. This also applies to the engine. Most likely it will be a Chinese engine...Chinese jet engine tech would have somewhat matured(depending on which engine it is) by then since Azm is at least 10 years out.

I think it would be something along the lines of JF17...indigenous enough to give PAF control over its design and specs but not entirely in terms of in house production.

 

[randomradio]

it's a clean sheet design and I was shocked

Hi,

The question should have been---why is it an indigenous design---why---what is the reason behind it---what is the engineering base behind it to have own design rather than the already existing J31---.

How is it that Pakistan can afford to experiment when the enemy is inducting aircraft after an aircraft---?

This tantamounts to treason against the state---.

Hasn't the Paf learnt from JF17 that such projects run 10-15 years behind with just one hiccup---.

It looks like the Paf has bigger egos than their brains---.

It is more like a di-ck measuring contest---.

Isn't it also possible that it's a flying wing unmanned aircraft like the Neuron? This is something you will have to develop on your own. No one's gonna supply it.

 

[Shabi1]

I have few points here. No doubt Air University has the people with the ability to design a aircraft and they must have but practicality dictates a complete new design on its own by PAF does not make sense for project Azm. Pakistani engineers must have made proposals and designs but its upto the higher ups to decide what to select what goals are achievable and which have to be outsourced. For a project of this magnitude there must have been several design studies and proposed layouts. Fortunately for Pakistan it has Turkish and Chinese collaboration options so it is not a necessity that we make it on our own, we have options. Turkey itself is not too urgent about it´s own stealth jet because of F-35 and SU-57 prospects, but they can offer sub systems. Pakistan´s urgency leans it towards China for the airframe part.

Here´s whats confirmed so far from ACM.
1. China will assist Pakistan in the airframe development. This is the most important point
2. Expected date is 2025. And this is for start to replace jets.
3. Big emphasis on self reliance and integration.

What we can deduce.
4. PAF will use off the shelf components with TOT capability, which means Radar, engine and avionics suite will be sourced as it cannot invest the the funds and neither has the time to develop new systems from scratch.
5. Off the shelf components ease risks and avoid development costs as the product is ready and performance can be shortlisted from various sources.

Since China is doing the airframe part they will design it, PAF will have a say about the direction but its their strength and we should leave it to them. This single reason is enough to confirm whatever the design the Azm has it is by a Chinese chief designer. and this is what is convenient for China and they would have pushed for it. Turkish industry and western products will be evaluated wherever possible.

Now what we know about J-31
1. China has not committed to it and it is so far an export only fighter. Even on carrier borne front, J-15 and J-16 are their carrier born fighters and there is no official intention to change that. I personally don´t think J-31 will have carrier capability because if you read on J-31 they have used some new design approaches to reduce number of parts, downside of this is wings cannot be separated from the fuselage. Reason why prototype transported on truck rather than by air. So wing folding mechanism was not intended.
''Officials from AVIC claimed that additive manufacturing was extensively used on the aircraft, resulting in 50% reduction in components compared to similar aircraft. However, the resulting airframe cannot be disassembled, and the static test frame had to be transported in whole as a consequence.[28]''
2. If China is assisting Pakistan on a new type of stealth fighter keeping the J-31 project alive does not make sense. Whey make efforts in a design which your primary customer will not buy.
3. J-31 will achieve FOC by 2024 and third prototype is expected to be larger and is awaiting the WS-13/RD-93MA availability in mid/later 2019. Chinese rumored access to F-35 material from data hacks have likely had influence on J-31.

From the above and the timeline regardless of everything it is very safe to assume no matter what anyone claims Azm will be largely based on the J-31. Even if PAF originally wanted a complete new design, since China is crucial for Azm airframe development they would have persuaded to make the it based on the J-31 or would have abandoned their own further work on the J-31. Later is not happening.

However final confirmation will take years to get and it is unlikely that a ranking PAF official with the actual access to decisions taken will leak information to a forum like this till it´s ready without fear of a court martial. Reason for the secrecy is simple, delay release of information for as long as possible to avoid over reaction by India. Right now India´s induction plans seem to be bogged down in tender processes but as soon as PAF releases details India will as it has done before will go on panic shopping mode.

 

[Army research]

Hi,

The question should have been---why is it an indigenous design---why---what is the reason behind it---what is the engineering base behind it to have own design rather than the already existing J31---.

How is it that Pakistan can afford to experiment when the enemy is inducting aircraft after an aircraft---?

This tantamounts to treason against the state---.

Hasn't the Paf learnt from JF17 that such projects run 10-15 years behind with just one hiccup---.

It looks like the Paf has bigger egos than their brains---.

It is more like a di-ck measuring contest---.

I don't know sir, I asked them the same thing but it's up to the tiger ups, hopefully they buy 31 separately as well

 

[Hayreddin]

Traitors are people like you, always ready with advice that makes Pakistan ever more dependent on foreign technology and in danger of sanctions.

Given the cost of modern aircraft, one point is evident: manufacturers will fleece you dry if you want top of the line technology. Accoess to top end technology has become a rich persons' club - you pay through your nose to play.

In this backdrop, hats off to our top leadership for their visionary thinking. If we don't start now, then for ever more we will be dependent on little morsels thrown by others. Alhamdulillah this is our first step towards becoming self-sufficient. May Allah Help Pakistan in overcoming it's enemies and upholding His Commands throughout the world. Aameen.

You get it all wrong mate . It not about project azm , indeed its a revolutionary and visionary project but in a mean while we need 4.5 gen atleast 4 sqdn . Jft blck 3 cant fulfill needs . Paf is heavily outnumbered qualitatively and quantitately . Fact is fact jft blck 3 cant compete with 270 su30s and 36 rafale . Yes outnumbered jft can engage su30 and rafale but result wld be same as amateur fighet going against brock lesnar .

 

[Armchair]

I have few points here. No doubt Air University has the people with the ability to design a aircraft and they must have but practicality dictates a complete new design on its own by PAF does not make sense for project Azm. Pakistani engineers must have made proposals and designs but its upto the higher ups to decide what to select what goals are achievable and which have to be outsourced. For a project of this magnitude there must have been several design studies and proposed layouts. Fortunately for Pakistan it has Turkish and Chinese collaboration options so it is not a necessity that we make it on our own, we have options. Turkey itself is not too urgent about it´s own stealth jet because of F-35 and SU-57 prospects, but they can offer sub systems. Pakistan´s urgency leans it towards China for the airframe part.

Here´s whats confirmed so far from ACM.
1. China will assist Pakistan in the airframe development. This is the most important point
2. Expected date is 2025. And this is for start to replace jets.
3. Big emphasis on self reliance and integration.

What we can deduce.
4. PAF will use off the shelf components with TOT capability, which means Radar, engine and avionics suite will be sourced as it cannot invest the the funds and neither has the time to develop new systems from scratch.
5. Off the shelf components ease risks and avoid development costs as the product is ready and performance can be shortlisted from various sources.

Since China is doing the airframe part they will design it, PAF will have a say about the direction but its their strength and we should leave it to them. This single reason is enough to confirm whatever the design the Azm has it is by a Chinese chief designer. and this is what is convenient for China and they would have pushed for it. Turkish industry and western products will be evaluated wherever possible.

Now what we know about J-31
1. China has not committed to it and it is so far an export only fighter. Even on carrier borne front, J-15 and J-16 are their carrier born fighters and there is no official intention to change that. I personally don´t think J-31 will have carrier capability because if you read on J-31 they have used some new design approaches to reduce number of parts, downside of this is wings cannot be separated from the fuselage. Reason why prototype transported on truck rather than by air. So wing folding mechanism was not intended.
''Officials from AVIC claimed that additive manufacturing was extensively used on the aircraft, resulting in 50% reduction in components compared to similar aircraft. However, the resulting airframe cannot be disassembled, and the static test frame had to be transported in whole as a consequence.[28]''
2. If China is assisting Pakistan on a new type of stealth fighter keeping the J-31 project alive does not make sense. Whey make efforts in a design which your primary customer will not buy.
3. J-31 will achieve FOC by 2024 and third prototype is expected to be larger and is awaiting the WS-13/RD-93MA availability in mid/later 2019. Chinese rumored access to F-35 material from data hacks have likely had influence on J-31.

From the above and the timeline regardless of everything it is very safe to assume no matter what anyone claims Azm will be largely based on the J-31. Even if PAF originally wanted a complete new design, since China is crucial for Azm airframe development they would have persuaded to make the it based on the J-31 or would have abandoned their own further work on the J-31. Later is not happening.

However final confirmation will take years to get and it is unlikely that a ranking PAF official with the actual access to decisions taken will leak information to a forum like this till it´s ready without fear of a court martial. Reason for the secrecy is simple, delay release of information for as long as possible to avoid over reaction by India. Right now India´s induction plans seem to be bogged down in tender processes but as soon as PAF releases details India will as it has done before will go on panic shopping mode.

The problem with the point that the FC-31 will be the base airframe for the Azm project are as follows:

1. The design does not lend to a credible fighter aircraft with twin RD-93 MA / etc.
2. Airframes are the easy part, new gen CAD programs have seen to that. unless you are talking about stealth materials and new technologies of building (3D, additive manufacturing).
This is a lesson learned from the F-35 program - there was very little to gain and a lot to lose by attempting to use a common air-frame.
The world is still stuck in the mindset of hard-manufactured "frames" but these things now make up a small fraction of the cost of building a combat aircraft.
The real costs are subsystems and sub-system integration / fusion.
3. Stealth is very costly. PAF cannot afford a proper stealth jet ala F-35 or F-22. Even if they were gifted, the CPFH is 45000 to 70000 USD.
4. The high cost of maintenance includes the cost of constantly repairing the skin. If the Chinese have developed such skins, and using them on the J-31 (I hear talk of nano-tubes, that the Chinese have mastered, the latest gen of stealth), this won't help PAF with its fighter. PAF needs a simple, easy to repair and operate aircraft. If you did that to the J-31, you'd have the worst of both worlds - a shitty aerodynamics and a shitty stealth aircraft.
5. All of this means PAF needs a design that is suitable for it and not a highly unsuitable J-31.

Remember that the J-20 was originally designed without canards. A younger brother of the J-20 probably resides in CAC's drawing boards. There were always rumors of the "twin engined J-10" for as long as I remember. What this means is that CAC probably has a highly mature Flight Control System that can be tweaked for the Azm.

It makes sense for me, therefore, to believe that Azm would be a LO and not a VLO design, with a custom airframe suited to PAF's needs, built for twin RD-93MAs or Chinese equivalents. PAF could go the Rafale route of using sensor fusion and advanced EW to compensate for the lack of stealth. This would thus be a balance of stealth and EW, taking a middle-path between the US / China on the one hand and France / Russia on the other.

I do not believe that in this day and age, it makes sense to take an airframe design and copy it. This actually doesn't necessarily save much money or time.

 

[randomradio]

What we can deduce.
4. PAF will use off the shelf components with TOT capability, which means Radar, engine and avionics suite will be sourced as it cannot invest the the funds and neither has the time to develop new systems from scratch.

You will only get previous generation stuff if you want to design a new aircraft. No one will help you out with the latest hardware, not even the Chinese.

The idea behind having an aircraft development program is to make your own stuff. Or else it will fail.

Take India for example. We have the Israel advantage. The Israelis are capable enough to develop systems, but can't develop the entire platform, so they sell whatever they develop to India. But when India held a tender for the LCA's radar, only the Israelis and French participated. And the French participated because we bought the Rafale already and they wanted to sell us Rafale related tech. The Americans and Swedish, who did not get any aircraft order guarantees, backed out.

No one will give you technology if you simply ask for it. The Chinese also will not sell you the latest stuff because they want you to be dependent on them. So no tech from China if you can't spend on Chinese stuff first, like the French did with India.

Go big or go home.

Right now India´s induction plans seem to be bogged down in tender processes but as soon as PAF releases details India will as it has done before will go on panic shopping mode.

India's procurement plan is entirely independent from what Pakistan buys. Pakistan reacts to an Indian purchase, not the other way round.

 

[Shabi1]

You will only get previous generation stuff if you want to design a new aircraft. No one will help you out with the latest hardware, not even the Chinese.

The idea behind having an aircraft development program is to make your own stuff. Or else it will fail.

Take India for example. We have the Israel advantage. The Israelis are capable enough to develop systems, but can't develop the entire platform, so they sell whatever they develop to India. But when India held a tender for the LCA's radar, only the Israelis and French participated. And the French participated because we bought the Rafale already and they wanted to sell us Rafale related tech. The Americans and Swedish, who did not get any aircraft order guarantees, backed out.

No one will give you technology if you simply ask for it. The Chinese also will not sell you the latest stuff because they want you to be dependent on them. So no tech from China if you can't spend on Chinese stuff first, like the French did with India.

Go big or go home.



India's procurement plan is entirely independent from what Pakistan buys. Pakistan reacts to an Indian purchase, not the other way round.

Chinese have always given Pakistan access to their best provided their own procurement requirements have been met. They have tried hard to sell there latest SAMs, Ships, WZ-10s, VT4s and etc all of their top of the line products. Pakistan has not always been receptive because it doesnt want to be too reliant or it feels they need to mature more. J-20 is design is built for long endurance ranges at expense of less maneuverability, those canards are there for added lift. PAF requirements are multirole, highly maneuverable, something more cost effective to field, lower maintenance and high availability.

There has not been a single item to date where Pakistan has requested but it was not provided by China. So your argument has no base as there is no precedent.

Now for aircraft program. The idea behind a aircraft is not make your own stuff, its to acquire a capability for your AF. If reliable supplier for components not available or the technology level is not available only then you make it yourself or if you really want to make everything yourself you have to spend extra , increase risk and expand the timeline. Japanese F2 and Indian LCA are examples, both ran into over runs and delays because of emphasis on local development. In case of LCA even the local radar and engine were failures so had to outsource them in the end which was an unnecessary waste of resources and time, they should have opted for available options from the start.

With Azm PAF wants a customized 5th gen aircraft tailored to its needs. PAF does not have the extra time to develop everything itself or can it afford the risk of failure. It can follow how Israel developed its industry their systems all started as local productions of US and French sub systems and then they started gradually improving them into new variants. It has a tested and successful development example of the JF-17 program which it can repeat but with greater control on integration. Just as Israel started with it´s aviation industry PAF now manufactures radars and avionics for the JF-17 locally and suppliers are keen to share their technologies because of competition and future collaboration prospects. This is why I think Azm will follow suite and be heavily based on the J-31. And I would like to add J-31 in it´s current form is not ready there are alot of expected changes to improve it. Super cruise is one of the features to be added once new powerplant available next year.

And for procurement. Please check your media and analysts reactions whenever we buy something followed by campaigns to boost fundings and speed up procurements.

The problem with the point that the FC-31 will be the base airframe for the Azm project are as follows:

1. The design does not lend to a credible fighter aircraft with twin RD-93 MA / etc.
2. Airframes are the easy part, new gen CAD programs have seen to that. unless you are talking about stealth materials and new technologies of building (3D, additive manufacturing).
This is a lesson learned from the F-35 program - there was very little to gain and a lot to lose by attempting to use a common air-frame.
The world is still stuck in the mindset of hard-manufactured "frames" but these things now make up a small fraction of the cost of building a combat aircraft.
The real costs are subsystems and sub-system integration / fusion.
3. Stealth is very costly. PAF cannot afford a proper stealth jet ala F-35 or F-22. Even if they were gifted, the CPFH is 45000 to 70000 USD.
4. The high cost of maintenance includes the cost of constantly repairing the skin. If the Chinese have developed such skins, and using them on the J-31 (I hear talk of nano-tubes, that the Chinese have mastered, the latest gen of stealth), this won't help PAF with its fighter. PAF needs a simple, easy to repair and operate aircraft. If you did that to the J-31, you'd have the worst of both worlds - a shitty aerodynamics and a shitty stealth aircraft.
5. All of this means PAF needs a design that is suitable for it and not a highly unsuitable J-31.

Remember that the J-20 was originally designed without canards. A younger brother of the J-20 probably resides in CAC's drawing boards. There were always rumors of the "twin engined J-10" for as long as I remember. What this means is that CAC probably has a highly mature Flight Control System that can be tweaked for the Azm.

It makes sense for me, therefore, to believe that Azm would be a LO and not a VLO design, with a custom airframe suited to PAF's needs, built for twin RD-93MAs or Chinese equivalents. PAF could go the Rafale route of using sensor fusion and advanced EW to compensate for the lack of stealth. This would thus be a balance of stealth and EW, taking a middle-path between the US / China on the one hand and France / Russia on the other.

I do not believe that in this day and age, it makes sense to take an airframe design and copy it. This actually doesn't necessarily save much money or time.

I´ve been reading your posts and realize you have made up your mind about the ideal AA platform, a delta wing design with no canards or a YF-23 type design. It sounds pretty good but what you are often referring to is more similar to FB-22 which is a bomber. What PAF would want to have is a design which is more multirole.
https://en.wikipedia.org/wiki/Lockheed_Martin_FB-22

With Azm the goal will likely be a jet which is both stealth (confirmed) and sensor fused/EW optimized. Sensor fused for AA and stealth for when in a strike role. The new design you are proposing can be done but it will make the project more expensive and will take several more years unrealistic for the timeline given by PAF. There are pros and cons for both the new design and the J-31 approach. Lets just agree to disagree and let it be. Will find out in few years whose approach is similar to whats taken.
And in no way Azm will be PAFs final jet there could be Azm 2 or a AA UCAV after this so lets just meet current needs right now.

As for twin J-10C/D, Im waiting to see how it turns out, if threat is too much for PAF to handle and it needs quick inductions it could be a reality.

 

[ACE OF THE AIR]

You get it all wrong mate . It not about project azm , indeed its a revolutionary and visionary project but in a mean while we need 4.5 gen atleast 4 sqdn . Jft blck 3 cant fulfill needs . Paf is heavily outnumbered qualitatively and quantitately . Fact is fact jft blck 3 cant compete with 270 su30s and 36 rafale . Yes outnumbered jft can engage su30 and rafale but result wld be same as amateur fighet going against brock lesnar .

The issue of getting atleast 4 sqdn of 4.5 gen is going to be addressed once JF-17-blockIII's are produced. Now it is up to PAF funds if she wishes to procure them in higher numbers i.e 50 are on order +50~100. It is very difficult that this airframe will be further enhanced. The addons that might be available are CFT and Stealth Weapons Pod.

Quantitative disadvantage can be addressed by SAM's, where as qualitative edge will be almost equal in a netcentric theater something PAF has been working on.

1. The design does not lend to a credible fighter aircraft with twin RD-93 MA / etc.

This is true. However the J-31 may be powered by the upgraded RD-93 which PAF has contributed to incase PAF does decide to purchase it.

2. Airframes are the easy part, new gen CAD programs have seen to that. unless you are talking about stealth materials and new technologies of building (3D, additive manufacturing).
This is a lesson learned from the F-35 program - there was very little to gain and a lot to lose by attempting to use a common air-frame.

It depends on what the airframes are being designed for.
There are basically two fundamental designs i.e the US model or the Russian model.
US model is more to do with cloaking where as Russian is based on bouncing the rays away so that they do not return.

The F-35 A and F-35B are were not based for the US alone but for other allies as well so they had to be designed keep a broader parameter. They had to replace not only air superiority fighters but also ageing naval platforms. Once again the rebirth of jump jets emerged because most of the European aircraft carriers were becoming smaller and LHD could also support these giving more flexibility and a larger market.

The world is still stuck in the mindset of hard-manufactured "frames" but these things now make up a small fraction of the cost of building a combat aircraft.
The real costs are subsystems and sub-system integration / fusion.

With the world leading to satellite based infrastructure and limitation on use of weapons in outer space these requirements have arisen. However with both Russia and USA trying to build anti-satellite missiles would change the complexion of these scenarios.

3. Stealth is very costly. PAF cannot afford a proper stealth jet ala F-35 or F-22. Even if they were gifted, the CPFH is 45000 to 70000 USD.

Not to mention the turn around time is also very high

4. The high cost of maintenance includes the cost of constantly repairing the skin. If the Chinese have developed such skins, and using them on the J-31 (I hear talk of nano-tubes, that the Chinese have mastered, the latest gen of stealth), this won't help PAF with its fighter. PAF needs a simple, easy to repair and operate aircraft. If you did that to the J-31, you'd have the worst of both worlds - a shitty aerodynamics and a shitty stealth aircraft.

The issue is how much has Pakistan committed to in this regards (both monetarily and human resources)

5. All of this means PAF needs a design that is suitable for it and not a highly unsuitable J-31.

Please look at the single engine TFX design. That might be the one PAF considers.

Remember that the J-20 was originally designed without canards. A younger brother of the J-20 probably resides in CAC's drawing boards. There were always rumors of the "twin engined J-10" for as long as I remember. What this means is that CAC probably has a highly mature Flight Control System that can be tweaked for the Azm.

PAF might not take one design and work on it rather take a few and infuse various parts. Something like the JF-17. It does resemble F-18...The JF-17 be is very similar to Tornado.

It makes sense for me, therefore, to believe that Azm would be a LO and not a VLO design, with a custom airframe suited to PAF's needs, built for twin RD-93MAs or Chinese equivalents. PAF could go the Rafale route of using sensor fusion and advanced EW to compensate for the lack of stealth. This would thus be a balance of stealth and EW, taking a middle-path between the US / China on the one hand and France / Russia on the other.

PAF would most likely build an airframe and then decide which engine suites it the most i.e modular design that can incorporate not just Russian and Chinese engines but also Ukrainian, Turkish and British engines.

I do not believe that in this day and age, it makes sense to take an airframe design and copy it. This actually doesn't necessarily save much money or time.

This is true.

With Azm PAF wants a 5th gen aircraft. PAF does not have the extra time to develop everything itself or can it afford the risk of failure. It has a tested and successful development example of the JF-17 program which it can repeat but with greater control on integration. This is why I think Azm will follow suite and be heavily based on the J-31. And I would like to add J-31 in it´s current form is not ready there are alot of expected changes to improve it. Super cruise is one of the features to be added once new powerplant available next year.

What if PAF does procure limited numbers of J-20 and look towards 6th gen aircraft.

I´ve been reading your posts and realize you have made up your mind about the ideal AA platform, a delta wing design with no canards or a YF-23 type design. It sounds pretty good but what you are often referring to is more similar to FB-22 which is a bomber. What PAF would want to have is a design which is more multirole.
https://en.wikipedia.org/wiki/Lockheed_Martin_FB-22

The YF-23 design can be developed up to have airsuperiorty or multirole whereas the F-22 can not.

As for twin J-10C/D, Im waiting to see how it turns out, if threat is too much for PAF to handle and it needs quick inductions it could be a reality.

Lets see but may be the Russians can offer the PAK-FA as India has refused to procure those in favour of AMCA. In reality the F-35 is going to be preferred by India as Israel is going to lobby for them, may be with Israeli systems.

@Armchair
http://understandingairplanes.com/Stealth-Airplane-Design.pdf