Pakistan Air Force | News & Discussions.

[Bilal Khan (Quwa)]

Just curious why JF-17s don't use more carbon composites. Building airplanes out of aluminum to many US aeronautical engineers is considered outdated and illogical. I am sure PAF has its reasons for keeping really old school. Burt Rutan would be exasperated.

As @FuturePAF noted, it's almost certainly cost.

It was also a design decision back in the early 1990s, and back then, the things we take for granted today weren't assured. It didn't just eschew composites, but also relaxed stability, fully fly-by-wire, etc as well. Each of these things were either out-of-reach or experimental-stage in China when the JF-17 was on the drawing board.

Sure, it sounds odd and all, but the JF-17 was and still is meant to supplant the F-7P/PG and Mirages, so an exponential leap wasn't needed from that standpoint. It was also meant to work with the F-16 (and Mirage 2000/-5, when all that was a thing in the 1990s and early 2000s).

But with Project Azm, the PAF opted for high-performance (and high-risk) capabilities in the design requirements. In this case, the goal is to evidently to replace the F-16s, and to form up much needed capabilities (greater range, payload, etc for maritime as well as deep-strike and offensive operations).

That said, it would be interesting if the PAF puts some development money aside for continued JF-17 development in China (in parallel to Pr. Azm). The team at Chengdu can re-open the JF-17's design and introduce composites, relaxed stability, a new engine, etc. Offer us a low-cost way to replace the JF-17 Block-I, II and III (while the FGFA/NGF supplants the F-16s).

 

[Armchair]

As @FuturePAF noted, it's almost certainly cost.

It was also a design decision back in the early 1990s, and back then, the things we take for granted today weren't assured. It didn't just eschew composites, but also relaxed stability, fully fly-by-wire, etc as well. Each of these things were either out-of-reach or experimental-stage in China when the JF-17 was on the drawing board.

Sure, it sounds odd and all, but the JF-17 was and still is meant to supplant the F-7P/PG and Mirages, so an exponential leap wasn't needed from that standpoint. It was also meant to work with the F-16 (and Mirage 2000/-5, when all that was a thing in the 1990s and early 2000s).

But with Project Azm, the PAF opted for high-performance (and high-risk) capabilities in the design requirements. In this case, the goal is to evidently to replace the F-16s, and to form up much needed capabilities (greater range, payload, etc for maritime as well as deep-strike and offensive operations).

That said, it would be interesting if the PAF puts some development money aside for continued JF-17 development in China (in parallel to Pr. Azm). The team at Chengdu can re-open the JF-17's design and introduce composites, relaxed stability, a new engine, etc. Offer us a low-cost way to replace the JF-17 Block-I, II and III (while the FGFA/NGF supplants the F-16s).

If I had to guess, the Block 3 has relaxed stability, an auxiliary power unit, more composite use (still not enough IMHO), greater range payload and TWR.

 

[MastanKhan]

As @FuturePAF noted, it's almost certainly cost.

It was also a design decision back in the early 1990s, and back then, the things we take for granted today weren't assured. It didn't just eschew composites, but also relaxed stability, fully fly-by-wire, etc as well. Each of these things were either out-of-reach or experimental-stage in China when the JF-17 was on the drawing board.

Sure, it sounds odd and all, but the JF-17 was and still is meant to supplant the F-7P/PG and Mirages, so an exponential leap wasn't needed from that standpoint. It was also meant to work with the F-16 (and Mirage 2000/-5, when all that was a thing in the 1990s and early 2000s).

But with Project Azm, the PAF opted for high-performance (and high-risk) capabilities in the design requirements. In this case, the goal is to evidently to replace the F-16s, and to form up much needed capabilities (greater range, payload, etc for maritime as well as deep-strike and offensive operations).

That said, it would be interesting if the PAF puts some development money aside for continued JF-17 development in China (in parallel to Pr. Azm). The team at Chengdu can re-open the JF-17's design and introduce composites, relaxed stability, a new engine, etc. Offer us a low-cost way to replace the JF-17 Block-I, II and III (while the FGFA/NGF supplants the F-16s).

Hi,

Main issues with them are they are maintenance extensive---. Cracks are not easily visible---.

"

• Composites have high recurring costs.
• Composites are higher non recurring costs.
• Composites have higher material costs.
• Composites have very expensive repairs and maintenance.
• Composites needed isolation to prevent adjacent aluminium part galvanic corrosion "

 

[Armchair]

Hi,

Main issues with them are they are maintenance extensive---. Cracks are not easily visible---.

"

• Composites have high recurring costs.
• Composites are higher non recurring costs.
• Composites have higher material costs.
• Composites have very expensive repairs and maintenance.
• Composites needed isolation to prevent adjacent aluminium part galvanic corrosion "

I think the costs are over played. You simply need carbon composite sheets (flexible like curtain),resin and autoclave. You can then cast any part you want. It's that simple. You can see kids doing it in their garage on youtube. Sometimes people with book knowledge make simple things sound like reaching the moon.

 

[MastanKhan]

I think the costs are over played. You simply need carbon composite sheets (flexible like curtain),resin and autoclave. You can then cast any part you want. It's that simple. You can see kids doing it in their garage on youtube. Sometimes people with book knowledge make simple things sound like reaching the moon.

Puttar Ji,

Those are fiber glass---and not carbon fibre---hehehehehe.

 

[Armchair]

Puttar Ji,

Those are fiber glass---and not carbon fibre---hehehehehe.

Okay if you say so MK : )

 

[fatman17]

It was reported in September 2016 that Nigerian AF has decided to acquire JF-17. The initial batch of 3 JF-17N is expected to be delivered in November 2020. The first aircraft (2P-60?) was speculated to have been built by early 2020.

 

[Dazzler]

It was reported in September 2016 that Nigerian AF has decided to acquire JF-17. The initial batch of 3 JF-17N is expected to be delivered in November 2020. The first aircraft (2P-60?) was speculated to have been built by early 2020.
View attachment 614480

Perhaps all for Nigeria? 60-62

 

[Haris Ali2140]

Perhaps all for Nigeria? 60-62

View attachment 614493

View attachment 614486


View attachment 614487

What are these green patches???

 

[razgriz19]

Why would they put apu intake up on the tail when it sits near the landing bay?
Isn't the exhaust for apu right in the middle of the landing gear, behind the gun?



That's probably a ram air inlet for oil or avionics cooling

A great comparison of a PAF JF-17 Block 2 vs the Block 3 prototype.

(Image via Dazzler/PDF) https://t.co/fQL7Dcz0rS
View attachment 614262

 

[Dazzler]

What are these green patches???

Composites

 

[Haris Ali2140]

Composites

Whats the percentage of composites in BLK-2 & BLK-3???

 

[razgriz19]

Try repair a knick or a small dent in composite. See where that takes you vs. an aluminum sheet

I think the costs are over played. You simply need carbon composite sheets (flexible like curtain),resin and autoclave. You can then cast any part you want. It's that simple. You can see kids doing it in their garage on youtube. Sometimes people with book knowledge make simple things sound like reaching the moon.

 

[Dazzler]

Isn't this block 1?

No "visible" differences between blk 1 and 2.

Whats the percentage of composites in BLK-2 & BLK-3???

More than 20%..

 

[Talon]

No "visible" differences between blk 1 and 2.



More than 20%..

The serial of the said aircraft indicates it to be blk 1..no?