India eyes 6th generation FCAS, looks at tying up with France for possible collaboration

[Ginvincible]

Guys, there is no prize for strategic purity.

rather than learning and doing it by itself through investment and iteration over decades.

People have been saying this for decades. At some point “give it another 20-30 years” stops being a strategy and starts being a coping mechanism.

Maybe you can explain every failure individually, but the bet result is still the same. India has not built the institutional depth, long-term planning, procurement discipline or industrial execution needed to compete with the US, China or France in high-end combat aviation.

Indian engineers are obviously capable. The problem is the system they’re working inside. I am very pessimistic and believe it's impossible in India because its India.

and thus needs to run to someone else always for the scraps they are ready to throw.

Isn’t that literally what this thread is about?
A parliamentary committee is proudly talking about trying to get India into somebody else’s 6th gen program before any horizon for a 5th gen platform. They are even announcing it before an agreement is made.. Basically summarizes the potential of the current Indian state.

Joining a program run by someone else will not holistically build a domestic aerospace programs, pursuing indigenous programs does that.

Only if those programs actually deliver.

If “indigenous" development means another 25-30 years of delays while China fields the next generation, then this ideological purity is actively harming national security.

At some point capability matters more than the origin story.

If India keeps running and begging for these foreign run joint ventures it will always be some bloated regional power forever.

Better a bloated regional power than balkanized and dominated by outside powers.

I'm glad the leadership is at least able to swallow their pride, buy what they need and remain militarily relevant than spend another generation pretending the breakthrough is always just around the corner.

 

[Ginvincible]

France didn't adjust with Germany, then it won't adjust with India either bcoz small EU nations have different geography, geopolitics, economy, need, different than Asia/India.

When DRDO has made RAM, RAS, etc, working on DEW, TVC, etc then we don't need full airframe of FCAS/GCAP, just the engine & some components.

AMCA is not the end of combat jet design, but future jet design has to start today if not already started bcoz it takes 15-20 years. So if ADA won't put effort then PPP must.

The “we only need the engine and a few components” argument is exactly the kind of complacency that got India here. A 6th-gen fighter is not an airframe plus a shopping list of clever subsystems. The ability to manufacture and integrate all the pieces (propulsion, stealth, sensors, EW, weapons, software, etc) and sustainment into a functioning combat system is one thing. To then actually produce it at scale is where India struggles.

India will take what it can get and pay whatver it has to if it hopes to stay relevant. Maybe if they negotiate well, India gets the “co-developer” label. Maybe there are some photo ops, a few locally made parts and another Atmanirbhar Bharat graphic.

Just don’t confuse standing next to the people who built the technology with having built it yourself.

I really hope the next generation of Indians spends less time chest thumping over announcements and more time asking why, after decades of preaching “self-reliance,” India still has to go shopping abroad for the next rung of the aerospace ladder.

 

[jetray]

The ability to manufacture and integrate all the pieces (propulsion, stealth, sensors, EW, weapons, software, etc) and sustainment into a functioning combat system is one thing. To then actually produce it at scale is where India struggles.

Exactly , it is not simply assembling the components. Building the entire system from scratch puts you through a lot of grind which will increases the expertise , basically understand the nook & corner of what is technically feasible or not. Over a period of time help know your capability and improve it. There is no short cuts.

Just don’t confuse standing next to the people who built the technology with having built it yourself.

but it gives you instant fame & results , why go through the grind ? who cares if you spend $15 billion buying a foreign equipment as long as it is not your money ?

I really hope the next generation of Indians spends less time chest thumping over announcements and more time asking why, after decades of preaching “self-reliance,” India still has to go shopping abroad for the next rung of the aerospace ladder.

Not happening , if anything would have happened it would have happened long time back. Democracy in India is literally becoming a curse. Entry barrier for good ppl to get into the system has become huge. All we have is rotten ppl running show, who will never get displaced.

There is a reason why US fears china , they have great discipline , commitment and the urge to take on the world. They have been pretty remarkable it is not just one or years , but they have been good at it for last 3 decades. Even if they decline from now , they will still be ahead for another 2 decades or so.

 

[jetray]

here we go boys selling peanuts to monkeys.

https://twitter.com/x/status/2086349507852165433

 

[Saaho]

The “we only need the engine and a few components” argument is exactly the kind of complacency that got India here. A 6th-gen fighter is not an airframe plus a shopping list of clever subsystems. The ability to manufacture and integrate all the pieces (propulsion, stealth, sensors, EW, weapons, software, etc) and sustainment into a functioning combat system is one thing. To then actually produce it at scale is where India struggles.

India will take what it can get and pay whatver it has to if it hopes to stay relevant. Maybe if they negotiate well, India gets the “co-developer” label. Maybe there are some photo ops, a few locally made parts and another Atmanirbhar Bharat graphic.

Just don’t confuse standing next to the people who built the technology with having built it yourself.

I really hope the next generation of Indians spends less time chest thumping over announcements and more time asking why, after decades of preaching “self-reliance,” India still has to go shopping abroad for the next rung of the aerospace ladder.

I mean, think about it. Tejas is like an onion of trouble. You peal the outermost layer and new one shows up. Previously we believe it was GE's engine and now it is that Uttam and SRK (EW) not both certified on Tejas MK1A. Apparently SRK ie EW still is awaiting certification. This is on top of existing dispensation they got from IAF on maintainability.

Had DRDO and HAL bit only the Uttam part and had it integrated with a foreign EW suite, we would have had MK1A issue sorted. Perhaps. But no! Bloody all needs to be indigenous. In 2021, they added this BS too. An upgrade of D-29 EW suite. They wanted to develop it too. In 2021! They did not take Tejas MK1A as an opportunity to get the damn plane out ASAP but used it to add one more new development. They could have done development parallely on Su-30MKI and then added it to Tejas in future tranches. They had Mig-29 and Super Sukhoi to upgrade anyways. Instead of insisting of this on Tejas, from the beginning, Uttam and foreign EW should have been selected. Given Uttam to HAL and let it integrate it with Israeli SPJ pod and RWR.

See this pattern? This "We will do it all SAAAAR" is the bane of Indian development. Tejas also had this problem. They wanted airframe and control laws. They wanted Indian engine. They wanted Indian radar. Bloody hell they wanted god knows what else.

You do not want same in your sixth gen fighter. You want a new generation of fighter to actually work. You want to master the pipeline? Do it in tejas that you have already *censored*ed up. Do it in AMCA, likely you will *censored* up too.

 

[Saaho]

If India keeps running and begging for these foreign run joint ventures it will always be some bloated regional power forever.

LOL!
China when coming to arm its forces, even back in 50s or so, borrowed heavily from where-ever it could get its hands on whatever. They made things in China alright but they borrowed designs from entire world. These days they are in a business of claiming those designs where their to begin with or their designs were unique.

Type-56 Carbine? Russian SKS! Licensed.
Type-56 Rifle? Russian AK-47.
J-10 Fighter jet? Lavi. Though Chinese will make you believe it was something something J-9. No one has seen official design of J-9.
WS-10B Engine? CFM56 + some of their own design from another failed project. LOL!
KLJ-7? Heavily borrowed from RP-35 of Russia.
KLJ-7A? Very similar to Israeli ELM-2052. Someone need to find out how the hell Chinese get Israeli designs even before India. LOL!


Compare this to Tejas (Relaxed Stability design not even existing outside of F-16), A brand new F404 class engine, later revised to F414 LOL!, A new MMR radar while India had never made any airborne FCR.

Result. Chinese PLA has been better armed with their reliable russian small arms while India was still struggling with bolt action Lee-Enfield rifles in '62.
Result. Chinese PLAAF and now Pakistan AF is now equipped with AESA equipped modern jet in numbers. While we are still peeling layers of radar mess that we have, an engine that does not exist and whose placeholder is at our enemy's mercy, A jet design that was revolutionary in 90s but its most potential is now lost.

This is why you build step by step.

 

[Bhartiya Naagrik Sainik]

Skyroot had a technology injection from ISRO which developed on the springboard given by the early tech transfer that helped SLV-3 development: The CENS (french again) tech transfer of sounding rockets. PPP is not a magic bullet. Our history is filled with nothing but failed PPPs.

Problem is, Sixth gen is a brand new research and India does not have even Gen 5 and Gen 4.5 stuff fully mastered. Working with France is prudent given our history with them.

We basically need a tech injection of sorts. Like we got in ISRO. Like Bhaba got for our nuclear program and so on. Look at Turd-key. Those idiots have a much better aero space industry than India because they got the much needed tech from working with west being a NATO member.

Their Hurjet is already flying and looking for customers. Their K'aan, though a stupid design and equally stupid development has basic aircraft locked down. Their Kelijelima is more or less complete with BVR capability from a drone and not to mention, ability to land on carriers/cruisers. The reason is they did not have to learn each thing by bitter experience.

I highly doubt our private players can develop a sixth gen fighter out of nothing. Even 4th gen is a stretch. Its once more Tejas trap. And honestly, repeating the same again will be sign of stupidity.

We need to be specific.
I've already wrote since beginning that we need collaboration (seed / injection) on engine & some components.
Then why are you confused?

Apart from engine, which A/c components exactly are you talking about?

Basically, 6gen airframe is supposed to have -
- more fuel
- more internal weapons
- more electricity
- DEW-CIWS
- MUMT
- better geometry
- better RAM, RAS
- better computing, AI assisted
- VCE
- military internet

No gen's IOC jet is at full mastery level, hence it's called IOC, then comes FOC, then comes MLU.

Imagine an inflated AMCA, the laziest thing we can do, with Indo-French JV engine + DRDO's RAM, RAS, DEW, TVC, etc.
If HAL can't manufacture this airframe then PPP has to. Tata, Ambani were very eager to bag deal for F-16-IN, F-18 SH.

Now please tell us apart from engines what exactly DRDO/Indians cant make.

 

[Bhartiya Naagrik Sainik]

The “we only need the engine and a few components” argument is exactly the kind of complacency that got India here. A 6th-gen fighter is not an airframe plus a shopping list of clever subsystems. The ability to manufacture and integrate all the pieces (propulsion, stealth, sensors, EW, weapons, software, etc) and sustainment into a functioning combat system is one thing. To then actually produce it at scale is where India struggles.

India will take what it can get and pay whatver it has to if it hopes to stay relevant. Maybe if they negotiate well, India gets the “co-developer” label. Maybe there are some photo ops, a few locally made parts and another Atmanirbhar Bharat graphic.

Just don’t confuse standing next to the people who built the technology with having built it yourself.

This is neither argument nor complacency. I'm trying to put things in easy short way to understand. I can't put full 4 year engineering syllabus here.

Assembling a car, bus, truck is also complex. If we can assemble Su-30MKI, then also a bigger inflated AMCA.

Whatever more tools, forges, high ton press, etc are needed, if not already there then indeed should have been arranged by now.

Only HAL's current footprint cannot handle a big nation like India.

I really hope the next generation of Indians spends less time chest thumping over announcements and more time asking why, after decades of preaching “self-reliance,” India still has to go shopping abroad for the next rung of the aerospace ladder.

This same question need to be asked to GoI/MoD/DoD & 54,000 people passing out every year from top institutions & 5,00,000 people passed out in last 25 years. I already said we need newer gen of people with result & time oriented thinking & actions.

 

[screambowl]

Okay another topic to discuss for a decade without any visual results. It has become a joke now. A decade back the issue was jet engine and a decade after the issue will be jet engine only.

 

[Saaho]

We need to be specific.
I've already wrote since beginning that we need collaboration (seed / injection) on engine & some components.
Then why are you confused?

You are WRONG. Thats not how you build a new generation of aircraft. Look at successful fifth gen fighters. Custom Engine. Custom Electro Optical sensors. Custom cooling tricks (which require to be integrated into engine too). Custom radar. Custom data fusion. Custom networking solutions. F-22 and F-35 are so different from earlier fighters that you can not hope to make one from the existing parts.

This is why "specifics" is a wrong question to ask. We do not even know at this point what specific things we will need besides that Sixth gen will be able to command a bunch of drones too.

Look at J-20. It has a custom engine, custom radar, custom electro optics and so on.

Apart from engine, which A/c components exactly are you talking about?

Everything! Nothing major we make today can fit the sixth gen design. Sixth Gen thrust to weight requirements are going to be totally different. Its Radar will need totally different capabilities. Its EOs will be radically different that what we are studying right now for fifth gen. Its weapons may include what are just concepts right now, like DEWs.

A new generation of fighter is not like assembling a computer that you can say we have motherboard, ram, processor, sdd, gpu, Let Go!

It is more like developing a new macbook pro. Every darn thing needs to be custom for it.

Basically, 6gen airframe is supposed to have -
- more fuel
- more internal weapons
- more electricity
- DEW-CIWS
- MUMT
- better geometry
- better RAM, RAS
- better computing, AI assisted
- VCE
- military internet

The honest answer is, we do not know. Outside of China and US, no one has one flying. So we do not know what are the requirements. We do not even know what will be defining charecterstics of the sixth generation. We just have heard some ideas.

This is why we need to work with someone who has an idea and has developed fighters from grounds up.

 

[RationalGuy]

LOL!
China when coming to arm its forces, even back in 50s or so, borrowed heavily from where-ever it could get its hands on whatever. They made things in China alright but they borrowed designs from entire world. These days they are in a business of claiming those designs where their to begin with or their designs were unique.

Type-56 Carbine? Russian SKS! Licensed.
Type-56 Rifle? Russian AK-47.
J-10 Fighter jet? Lavi. Though Chinese will make you believe it was something something J-9. No one has seen official design of J-9.
WS-10B Engine? CFM56 + some of their own design from another failed project. LOL!
KLJ-7? Heavily borrowed from RP-35 of Russia.
KLJ-7A? Very similar to Israeli ELM-2052. Someone need to find out how the hell Chinese get Israeli designs even before India. LOL!


Compare this to Tejas (Relaxed Stability design not even existing outside of F-16), A brand new F404 class engine, later revised to F414 LOL!, A new MMR radar while India had never made any airborne FCR.

Result. Chinese PLA has been better armed with their reliable russian small arms while India was still struggling with bolt action Lee-Enfield rifles in '62.
Result. Chinese PLAAF and now Pakistan AF is now equipped with AESA equipped modern jet in numbers. While we are still peeling layers of radar mess that we have, an engine that does not exist and whose placeholder is at our enemy's mercy, A jet design that was revolutionary in 90s but its most potential is now lost.

This is why you build step by step.

How much they shelled out to get those stuff? An arm and a leg that the French will take (along with core ownership of the core technologies)?

You're really comparing this to J10? Like really? As if we will have that level of control.

This will be the flying version of the Scorpene lol. We will be "involved" in it and pay billions and wont learn dog crap from it.

 

[RationalGuy]

Guys, there is no prize for strategic purity.


People have been saying this for decades. At some point “give it another 20-30 years” stops being a strategy and starts being a coping mechanism.

Maybe you can explain every failure individually, but the bet result is still the same. India has not built the institutional depth, long-term planning, procurement discipline or industrial execution needed to compete with the US, China or France in high-end combat aviation.

Indian engineers are obviously capable. The problem is the system they’re working inside. I am very pessimistic and believe it's impossible in India because its India.


Isn’t that literally what this thread is about?
A parliamentary committee is proudly talking about trying to get India into somebody else’s 6th gen program before any horizon for a 5th gen platform. They are even announcing it before an agreement is made.. Basically summarizes the potential of the current Indian state.


Only if those programs actually deliver.

If “indigenous" development means another 25-30 years of delays while China fields the next generation, then this ideological purity is actively harming national security.

At some point capability matters more than the origin story.


Better a bloated regional power than balkanized and dominated by outside powers.

I'm glad the leadership is at least able to swallow their pride, buy what they need and remain militarily relevant than spend another generation pretending the breakthrough is always just around the corner.

So not joining some foreign run show and not always running to others for help = balkanization now? US with all of its technology can't even deal with Iran but somehow the Chinks are gonna get India? Listen to yourself dude cmon.

China ever being in a position to balkanize India is basically never gonna happen. Write that down with red ink pen.

India has shown it has the capability to execute complex national projects and build an ecosystem over time. We did it with nuclear subs, we did it with our space program. Now we need to do it with military aeronautics. If we went by your logic we would still be begging Russians to launch our stuff with on that old rickety R7 cuz, apparently the India is India and can't master complex tech over time.

 

[RationalGuy]

You are WRONG. Thats not how you build a new generation of aircraft. Look at successful fifth gen fighters. Custom Engine. Custom Electro Optical sensors. Custom cooling tricks (which require to be integrated into engine too). Custom radar. Custom data fusion. Custom networking solutions. F-22 and F-35 are so different from earlier fighters that you can not hope to make one from the existing parts.

This is why "specifics" is a wrong question to ask. We do not even know at this point what specific things we will need besides that Sixth gen will be able to command a bunch of drones too.

Look at J-20. It has a custom engine, custom radar, custom electro optics and so on.


Everything! Nothing major we make today can fit the sixth gen design. Sixth Gen thrust to weight requirements are going to be totally different. Its Radar will need totally different capabilities. Its EOs will be radically different that what we are studying right now for fifth gen. Its weapons may include what are just concepts right now, like DEWs.

A new generation of fighter is not like assembling a computer that you can say we have motherboard, ram, processor, sdd, gpu, Let Go!

It is more like developing a new macbook pro. Every darn thing needs to be custom for it.


The honest answer is, we do not know. Outside of China and US, no one has one flying. So we do not know what are the requirements. We do not even know what will be defining charecterstics of the sixth generation. We just have heard some ideas.

This is why we need to work with someone who has an idea and has developed fighters from grounds up.

Well what if the jet is made around their requirements which are pretty different from ours?

This entire thing is a sham and we are never gonna join this program in any realistic manner nor are we gonna buy this jet. This thing won't even fly before 2040.

 

[Bhartiya Naagrik Sainik]

You are WRONG.

I couldn't be an IITian even in dream but i try not to use this kind of direct -ve lines. I can be wrong but i'm putting things in simple way to understand. Everybody here may not be a qualified, experienced techie or going through DoD stuff everyday since 30 years.

Thats not how you build a new generation of aircraft. Look at successful fifth gen fighters. Custom Engine. Custom Electro Optical sensors. Custom cooling tricks (which require to be integrated into engine too). Custom radar. Custom data fusion. Custom networking solutions. F-22 and F-35 are so different from earlier fighters that you can not hope to make one from the existing parts.
This is why "specifics" is a wrong question to ask. We do not even know at this point what specific things we will need besides that Sixth gen will be able to command a bunch of drones too.
Look at J-20. It has a custom engine, custom radar, custom electro optics and so on.
Everything! Nothing major we make today can fit the sixth gen design. Sixth Gen thrust to weight requirements are going to be totally different. Its Radar will need totally different capabilities. Its EOs will be radically different that what we are studying right now for fifth gen. Its weapons may include what are just concepts right now, like DEWs.
A new generation of fighter is not like assembling a computer that you can say we have motherboard, ram, processor, sdd, gpu, Let Go!
It is more like developing a new macbook pro. Every darn thing needs to be custom for it.
The honest answer is, we do not know. Outside of China and US, no one has one flying. So we do not know what are the requirements. We do not even know what will be defining charecterstics of the sixth generation. We just have heard some ideas.
This is why we need to work with someone who has an idea and has developed fighters from grounds up.

Well, what you said about custom build is true & nobody is denying collaboration, but it's not that DRDO & other units not aware of it or should not do anything or not doing anything.

If India develops some kind of sensitive tech, will it give nice full access to SE Asian, African nations? So joining a project like FCAS/GCAP is not like a club membership giving access to all areas. Some new stuff will be kept secret, ToT denied.

It depends on exact components b/w the gens of jets. Some components are generic, some're gen specific.
Technically everything new can be developed/imported for a new gen, but it'll raise cost a lot. Western nations are fully capitalists, their currency value ratio to INR is very low, so they'll squeeze us financially.
So few generic things can be put into IOC & later new things be put in FOC, MLU.
Russia, China products quality may not match Western levels, but they're not sitting idle but proceeding with whatever they have & can do.



Engine & air cooling -> I said Indo-French JV.

Liquid cooling -> DRDO has something on AMCA called "Vapor compression cooling". Its scoop & exhaust is seen b/w the rudders. They may develop PAO kind of cooling like F-35 has:




Radar -> Uttam, Virupaksh, etc GaN AESA being developed.

Glass cockpit & display -> There're many pics of concepts demonstrated at Aero-India. IAF might be looking to have standard cockpits for most future jets, so that pilots can switch better b/w jets in emergency.

RAM, RAS -> DRDO made it:





EOTS -> AMCA's EOTS & IRST are being built. 6gen will have improved versions.






DEW -> DRDO working on it:



TVC -> DRDO working on it. Hopefully they'll develop stealthy nozzle.




6gen characteristics outline are known like i mentioned in points. If some people don't wanna accept it then it's their personal choice.

 

[GuardianRED]

Honestly - Unless a actual frame be it 5th or 6th moves down the runway under our Indian Sky's! I will take any news with a full pile of pink salt.

Im sure any sudden conflict we will see emergency procurement of at-least 2 frames of Su57 in IAF colours!

 

[Saaho]

How much they shelled out to get those stuff? An arm and a leg that the French will take (along with core ownership of the core technologies)?

You're really comparing this to J10? Like really? As if we will have that level of control.

This will be the flying version of the Scorpene lol. We will be "involved" in it and pay billions and wont learn dog crap from it.

Honestly, we are spending much less as a fraction of GDP on defense anyways. We pay a lot in pensions on top of it. I will say even if this costs additional 200 billion over 20 years, its worth it. Especially if India is going to be a 5 trillion dollar economy in coming 3 years.

One notable difference from Scorprene is that we got the final product and never got a front seat in development process.

Another interesting thing: the only fukken thing we let DRDO and our esteemed R&D folks do : the AIP is still not ready. For lord know what reason. I personally would have allowed MESMA AIP to be inducted and later in 10-15 years, additional follow on orders should have been allowed to induct our PAFC in new Scorpene subs.

The entire P75(I) has been a joke! Could have been avoided if we had allowed MESMA AIP and let our own mature and tested in a Kilo sub.

This is exactly the situation that is happening in our IAF too. Too many science project too few capabilities. There is a god damned AESA equiped 4.5 gen fighter in the waiting but it is hamstringed by certification of RWR. And low rate of GE engine production. LOL!

AMCA is going to be the same too. This time on F414 and possibly Electro Optics.

As @Ginvincile said, we celebrate announcement of projects and forget about the capabilities.

If FACS comes online, I will be happy because for the first time India military industry complex will get a master class in how to make new planes at the highest level.

 

[STEPHEN COHEN]

My 2 cents :

IAF has no trust in Su 57
So they are asking the Government for Getting inside the FCAS programme

Russia itself is relying on Missiles and Bombers in the Ukraine conflict so SU 57 development has stopped

 

[Saaho]

This is neither argument nor complacency. I'm trying to put things in easy short way to understand. I can't put full 4 year engineering syllabus here.

Assembling a car, bus, truck is also complex. If we can assemble Su-30MKI, then also a bigger inflated AMCA.

Whatever more tools, forges, high ton press, etc are needed, if not already there then indeed should have been arranged by now.

Only HAL's current footprint cannot handle a big nation like India.

Errr.... This is the fundamental problem in your understanding.

You can not design a relaxed stability frame in the same manner as a stable frame. It requires radically different thinking.
You can not make sixth gen aircraft using pure fourth gen approach. Some parts you will have to unlearn, some parts extend, some will be brand new.
Worse is that you do not know before hand which will be which.

Example :

We have design like Tejas, a delta wing jet with a tail. Sixth generation fighters are possibly tending to be tailless. You will have to unlearn the principles that you learnt in Tejas control laws (relaxed stability with fly by wire) and have to apply things like active flow control where jets of airflow are used to steer the plane (Tailless Jet Flies Free with Novel Control Technique). These are still research topics.

You can not make AMCA by inflating Su30-MKI. You can not make a sixth gen by just inflating fifth gen like wise. You build on that foundation but add more ideas and some time replace older ones.

My 2 cents :

IAF has no trust in Su 57
So they are asking the Government for Getting inside the FCAS programme

Russia itself is relying on Missiles and Bombers in the Ukraine conflict so SU 57 development has stopped

IAF has LEAST trust in HAL. That should be obvious. They will trust even Rusians over HAL right now. But when French are available then why not?
I think IAF is right here. Enough of this dog and pony show by ADA and HAL and DRDO. Let them deliver IJT, Tejas and AMCA. Then we will see about sixth gen. We will still be assembling new frames of Tejas in 2050 and 2047 will be celebrated by AMCA first flight.

 

[Batman]

It would be interesting to her @Hyperactive ADD take on this.

 

[Bhartiya Naagrik Sainik]

You can not design a relaxed stability frame in the same manner as a stable frame. It requires radically different thinking.
You can not make sixth gen aircraft using pure fourth gen approach. Some parts you will have to unlearn, some parts extend, some will be brand new.
Worse is that you do not know before hand which will be which.

Example :

We have design like Tejas, a delta wing jet with a tail. Sixth generation fighters are possibly tending to be tailless. You will have to unlearn the principles that you learnt in Tejas control laws (relaxed stability with fly by wire) and have to apply things like active flow control where jets of airflow are used to steer the plane (Tailless Jet Flies Free with Novel Control Technique). These are still research topics.

On a casual chat forum, in easy language -
> Forget 4gen Vs 5gen Vs 6gen, even within the same gen, different jets need different FCS coding after wind tunnel test, CFD analysis, etc.
> Relaxed stability means naturally unstable airframe, need computer to constantly move control surfaces.
> All fighter jets since 4gen use it. As per searching, F-16, Mirage-2000, Su-27 are 1st in their geo to use it. Tail-less jets like B-2 also use it.
> In traditional stable A/c, the CoG (Center of Gravity) is ahead of CoL (Center of Lift) producing nose down effect, to balance which the tail-stab or delta wing has to produce downward force or pitch up trim movement producing little trim drag.
> In relaxed stability or unstable A/c, the CoG move closer to CoL or behind it reducing & eliminating nose-down effect & needs FCS control.



> Anhedral (downward sloped) wings produce instability, Dihedral (upward sloped) wings produce stability.

> If we notice all 5gen jets & then all 6gen revealed so far via models or flying prototypes - FCAS, GCAP, J-36, J-50, they seem to have some common patterns-
- planform shaping
- fuselage side-walls slanted
- DSI or caret intakes
- high mounted, slightly anhedral, cropped-diamond wings
- outward canted rudders
- If rudders removed then yaw has to be produced by split aelerons, like in B-2 &/or sideways TVC.

You can not make AMCA by inflating Su30-MKI. You can not make a sixth gen by just inflating fifth gen like wise. You build on that foundation but add more ideas and some time replace older ones.

AMCA & Su-3X geometry are different, not comparable.

When i said to inflate AMCA doesn't mean duplicate & scale up as it is. Changing fuselage, wing size & shape changes CG (Center of Gravity) & (Center of Lift), which have to be tweaked. I'll show it in future in AHCA thread which i started 2 years back. Whoa! 2 years passed so fast! Damn!

Anyways, for time-pass on casual chat forum, the general public can visualize ideas with existing jets.
Stretch AMCA, replace DSI with caret intakes, it looks identical to F-22.




Stretch F-22, give it DSI, remove tail-stab, increase wings, clip the rudders, it looks identical to GCAP.







Stretch F-22, remove tail-stab, increase wings, remove rudders, bridge gap b/w nose tip & leading intake edge, it looks identical to J-36.

Errr.... This is the fundamental problem in your understanding.

On casual chat forum, my basics are clear to a certain minimum sufficient level. i try to search & grasp as many things as possible.