be concrete what materials are you referring to if you're talking about the composites....then as per our member nabil (one of the most informed source on JFT IMHO) has already indicated that even current JFTs have decent amount of composite materials on them
as per my information Kaveri is still underdevelopment and manufacturer is looking for a foreign partnership (P&W) APMI. PAF did not make any compromise on radar....PAC has long been running a radar factory and will be making Grifo radars under license and going forward JFT radar under licensing agreements as well(talking conservative) enhancing its exposure in this field...
In short....here is a simple answer about PAF's strategy
a. In my earlier post I have referred to 'increasing the proportion of composites' in JF 17 so I'm aware of JF17's composites presence (though not the ratio). But what's the specific difference I'm reffering to? The entire frame of LCA is made of composites including 95% of external skin to give it low RCS. This makes the plane 40% composite by weight. So you build the plane's structure with composites and throw in the engines, the avionics etc. with as few use of metals as possible. And we did this way back in 2001 when LCA's first prototype flew. Look at all major Indian aerospace projects:
'Light' Combat Aircraft
Advanced 'Light' Helicopter
'Light' Combat Helicopter
The'Light' part is used not only to indicate the tonnage/class in which they operate (ALH will not be that light in tonnage anyway), but also to indicate that they are made of composite light materials (the entire frame and not just some parts). With or without the LCA we've made hundreds of flying platforms with this tech (ALH/dhruv alone will run into hundreds)
Our new proposed civilian airline RTA 70 & the now flying SARAS also use light composites for their entire frame. GSLV Mark 3 is set to follow in these steps though I beleive the current GSLV too uses lots of composites (I don't know how much)
b. Kaveri, as I said, works as per the original specs not the new specs. Though I'm also tempted to ask how a smaller plane with lower combat range (and therefore lesser fuel) finds a comparable engine with JF 17 'underpowered' because I think even with 10% higher thrust the chinese engine will deliver about 55Kn of thrust, i won't ask it now because 92Kn for LCA as an Indian member said seems to be on the higher side. the 'under development' part is because the IAF now wants way way more thrust that the original specs.
c. You have to take a call. there is also an inherent risk in not having at least critical components in home. For us, it's never just about the final product, it's also about the capability. L&T, for instance, was a consutruction and high engineering major. They were drafted to build the hulls for nuke subs. That's how they built up ship building skills and then they decided to expand to ship building themselves. They've invested 1 Bn in one of Asia's largest ship yard and opened their order books with some 200 m worth of orders (who would question the ship building credibility of a company that's built nuke subs?). And that's how the money comes back over time. Same thing with LCA- Develop key tech and use it all over.