JamD
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Thank you for an educated reply. I'm just passing on the exasperation of US aeronautical engineers when they see a fighter jet made of aluminum alloy. Now, I am not saying go 100% with composites. Particularly when you talk of key structural components of wide bodied airliners. Those are gigantic and highly complex things. We are discussing instead components of a small fighter. Does it make sense to build so much of it from aluminum? It seems for the PAF it does. It seems also that US aeronautical engineers don't share that enthusiasm. Hope I made my point a bit clearer.
You've sort of answered your own concern. The JF-17 has composites in nonstructural places already. Those are relatively easy to design, maintain, replace. Keep in mind it's hard to find anything on an aircraft that isn't load carrying (even the skin carries a lot of load in some places).
There's plenty metal in US designs still. It's not like US engineers are looking at Aluminum with disdain or anything. It's an engineering decision not a high-school popularity contest. If the US DoD can dish out $220 million per plane, then the engineers have the freedom to incorporate all sorts of fancy composite structural members. It would be cost-prohibitive even for the US to go 100% composite. It's what you can afford and what capability it gets you.
It's not about lacking the capability to manufacture, diagnose, and maintain composites. There's plenty of people and tech in Pakistan that can do this correctly I can assure you of that. It's about the cost, both in manufacturing and maintenance.
Also whatever I said about composite aircraft structures was equally (if not more) true for small fighters. Airliners go through predictable cycles during operations. It's easier to account for composite fatigue in that case with decent models. Fighters go through harsh maneuvers that are "non-standard" and that's where you need either complicated models, sensors, or both to guess how your structure has degraded. My point is it isn't as simple as carbon fibre cloth lay up in an oven and you're done.
Yes they are. My point was simply an aircraft made with composites is significantly more expensive to design, manufacture, and operate. Just because you can doesn't mean you should. I am sure we will see much more significant use of composites in Azm because that will be an expensive and high-end aircraft. The JF-17 is a budget workhorse. It doesn't make sense for it to have a high percentage of composites. That would've reduced your JF-17 numbers by half and in return you would get maybe 10% more thrust to weight and 10% endurance. Not worth it if you ask me.Searching google scholar for 'composites in aerospace' turns up this gem. It validates some of what you say, but it corroborates that composites are heavily used in modern aircraft:
https://ihsmarkit.com/pdf/Composites-Aerospace-Applications-whitepaper_264558110913046532.pdf