> But war doesn't wait for decades. This time our bad situation could be exploited.1. Yes. It will take decades. More reason to not be hoodwinked again. I am sure some officials at high level back in 1950s, 1990s, 2000s,2010s would have said same thing while pondering over Marut, LCA, Kaveri and their funding. I have not made any personal comments, I am genuinely surprised over your take on 6th gen engine vis a vis India.
2. Comparing India's ecosystem with America is whole another issue. Let's save that discussion for other thread since it will open history chapters before from WW1.
> It is natural for different people to think differently & next 15 yrs are lot of time with current evolving H/w & S/w technologies for R&D. We know that USA started R&D during WW times but today's era is a speedy automated one.
> If Engine self reliance will take 5-10 years then why to sit idle for the airframe? A big geography like India can never be defended by only light & medium jets due to their limitations on fuel, payload, electricity. Hence GTRE or JV needs to aim for high thrust engine & a matching airframe.3. "There should be options to safeguard against army twisting".. Yes. But that doesn't happen by window shopping for another foreign engine. How are you gonna build an airframe like that? Even if by chance, two foreign nations have similar engines.. enabling feasible development of same airframe for both.. no one is going to sell you engine without exclusive guarantees. And the other vendor is not gonna keep its supply chain ready for "just in case" we need an option 20 years later. Even 404,135,177.. all are engines built for different platforms. So, even if IAF flies several categories of next gen platforms.. that doesn't mean that it will have several engine choices for each platform.
How will you negate arm twisting in that situation? Without self reliance.

> By options i don't mean 2 engines powering 1 jet, although techies can think such things after noticing F-15, F-16 using F100 & F110 engine variants. I wonder if they used plugs to fill gaps.

Then Russians also have series of engines & derivatives used in their Su-3X jets.
Any Indian aviation enthusiast will think that F414 engine for medium jet then why not a heavy engine for heavy jet.

> If J-20 started with AL-31 then why IAF operating 200+ Su-30MKIs not going for local heavy jet R&D with Al-31? Bcoz it is old engine?
Why not use AL-41? Bcoz it is new engine?
> TAI Kaan uses F110 engines. So i imagined a heavy jet using F100 or F110 engines when USA wanted to sell 4gen jets in MRCA tender.
> USA delayed F404 engines. USA twisted Turkey's arm as it purchased S-400 SAM. So getting F110 engine would be tough. Kaveri engine not ready.
Now AL-51 is new & AL-41 is old but good. Their hybrid Iz-177 also there. But people don't wan't those either.
So India neither did self R&D nor use either US or Russian heavy engine & hence now thinking on importing Su-57 & joining FCAS.
> But JV means we don't need to start from scratch as foreign makers are well experienced with small to big engines & have confidence.4. Your idea of different teams of DRDO looking into different things is already how it's different labs function. But you can't jump to 200+ thrust without achieving 98+ thrust. The thrust doesn't increase without advancing the science behind it. It includes ceramics, cooling , TVC too. Even the PPP partners need the required level of tech to develop higher thrust.
Your idea works in cases of US who have spent century developing engines from scratch. Once Pratt& Whitney have a 150+ KN engine.. they have the institutional knowledge continuity to now tweak it for a 50+, 70+ thrust engines. Not for India where our best iteration so far has been around 50+ dry thrust. Wether PPP or DPSU or Pvt ltd.. all will need to spend time, moolah and energy of their own to advance the same things DRDO is working on.
That's what the engine JV and AMCA project is supposed to do btw.
> If we compare 2 engines say F404 weighing 1 ton (391cm x 71cm) giving 49/79 KN thrust, with & F110 weighing 1.84 tons (462cm x 92cm) giving 84/145 KN thrust, so their mould, parts are of different size to start with. The JV engne would not start with F404 class, but F110 class.
> 10-15 years is good time to get to 200 KN class with economic improvements, increasing funding, metallurgic R&D, supercomputing, robotics, other automations, AI/ML, etc.
> Let GTRE take its time for Kaveri.
> I do understand aero-science to certain degree, the engine parameters like # of stages of LPC, HPC, HPT, LPT, crystal blades, film cooling, transpiration cooling, OPR, BPR, fuel types, fuel-air mix ratio, TET, design of combustor, flame holder, velocity triangle, CD duct, air mass flow, etc. All these things together create the desired thrust. And reading the specs & derivations & modifications, indeed some of these parameters are added, subtracted or modified in some ways.
> What do engine makers actually do for 5-10 years every day, 8-9 hrs/day of duty? They do calculations, try CFD models, make physical engines, test them for hours every day, check for malfunctions, stability, safety, etc. Right? Sometimes test engines melts, cracks, explodes too.
> But in the end i'm noticing pessimism rather than optimism.
We can discuss engine technology in this thread
Jet Engine Technology
> Exactly, not any time soon as per IST (Indian Stretchable Time)5. We don't have any project anytime soon which requires 2x F135 class engines. So, your point about will China's J-35, 50 wait is moot. Which airframe are you gonna fit that 6th gen engines on? Even AMCA isnt coming before 2040. No amount of 117,177,135 ( which themselves aren't 6th gen) is gonna overwhelm China if we have to depend on others for spares. Spares which might come from China too. Btw, very optimistic of you to think about India developing 6th gen engines by 2046 by developing step by step. It will be good if our own R&D'd 5th gen engines are in production by then. And it's normal and we need not be dettered by it.

Because new gen project takes 10-20 years broadly, so better to begin the soft/paper/CAD/CFD tasks today. Then we can have a prototype in 10 yrs by 2035 & IOC by 2040-45.> IMO the airframe is going to be DIY bcoz France may not modify FCAS to carry bigger weapons like Brahmos-NG, Rudram, etc.
> The production 6gen engine should be JV. The existing engines like AL-41, Iz-177 can be for TD jets.
> let's hope GTRE can make production ready 5gen engine in 15-20 years for AMCA Mk2 while its Mk1 will be powered by F414 with 80% ToT.
Our neighborhood has a Russian couple. Mrs Sukhoi delivered a baby boy & astonishingly named him Tejas.6. You idea and approch would make sense if you were talking about Engines for Tejas. But you're leapfrogging too much.

. So, your point about will China's J-35, 50 wait is moot. Which airframe are you gonna fit that 6th gen engines on? Even AMCA isnt coming before 2040. No amount of 117,177,135 ( which themselves aren't 6th gen) is gonna overwhelm China if we have to depend on others for spares. Spares which might come from China too. Btw, very optimistic of you to think about India developing 6th gen engines by 2046 by developing step by step. It will be good if our own R&D'd 5th gen engines are in production by then. And it's normal and we need not be dettered by it.


