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JF-17 Thunder Multirole Fighter [Thread 4]

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Giving it small tweaks is one thing, calling it stealth is another.

Just like the message above from Nabil, I have the same question. WHERE in ANY of my posts did I mention to turn JFT into Stealth?????? or that if we reduced the RCS, it'll become a stealth jet???

I think you oughta read what someone says, understand it and then counter the argument with yours. Burning cycles for the sake of argument is not really productive. I've mentioned many times, "Stealthy" does NOT equal to "Stealth". Please reread my posts, Nabil's, Gambit's and a few from Mastan Khan.
 
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The USA has had partial success with conversion of a contemporary fighter to a SEMI STEALTH fighter with F15SE...

The russians and chinease simply designed brand new fighters
Which incurred a lot of expense.
The reason why the F-15 is successful -- and I use that word cautiously -- is because of its inherent features, such as twin vertical stabs. Canting them is easier and would eliminate the dreaded 90 deg corner reflector.

f-22_raptor_tail_corner.jpg


The above is a corner reflector created by the F-22's rear quarters. In shaping for RCS control and reduction, the rules regarding corner reflectors are that avoid them completely, but if you cannot and a lot of the time you will not be able to, then avoid the 90 deg type. The F-15's twin vertical stabs can be re-positioned to eliminate the 90 deg type. We cannot do the same for the F-16 without incurring a lot of cost. Technically feasible? Yes. But financially effective? Dubious. If 'cost is no object' kind of mentality, then start anew, do not bother with trying to modify an existing airframe.

The corner is one example.

Another example is external stores. The F-15's conformal storage was originally designed for fuel and the system worked. It was only inevitable that they would be redesigned to carry weapons, but at the cost of reduced armament per sortie. We have no such for the F-16 because its fuselage design and shape. So far, the only places for the F-16 to carry anything enclosed are the dorsal spine and the two very oddly shaped conformal fuel tanks on the back, hardly safe for weapons.

The F-18 Super Hornet have a smaller RCS than the previous Hornets, but the SH is practically a different aircraft because it is a larger design and have some features like the F-15 that are conducive for RCS reduction.

Here is what I think Pakistan could do for the JF-17 if finance allows, but not 'no object' kind of mentality:

- Get rid of the single vertical stab. Do what the Iranians did for their F-5s.

- Install absorber on all leading edges.

- Re-shape all panels, such as using those 'saw tooth' patterns wherever gaps are likely to be in DIRECT contact with an impinging radar signal. Note: In RCS control, we call such physical shaping 'geometric absorber', which is contextually different than how a material like a sponge 'absorb' water. From the seeking radar perspective, if its signals actually impact a body but somehow the echoes are affected in any way, then as far as the seeking radar is concerned, the echoes have been 'absorbed'. Denial is considered 'absorption', hence the phrasing 'geometric absorber'. Not absorbed like a sponge.

f-18e_rcs_reduc_loc.jpg


The above is how much work is involved on panel gaps on an existing SHAPE, even a redesigned one like the F-18 SH. The F-22 is no different but just a lot less because it was designed from paper to have less of these small RCS related geometric issues. There were a lot of conflicts, mostly finance related, during the F-18SH design process, because of the desire to install those 'saw tooth' geometric absorber versus leaving the panel shapes as is and use the more maintenance intensive 'zip strips' methods to cover up those surface discontinuities. Guess who won the arguments? If it was not easy for US, what make anyone think it will be easy, financially and technically, for anyone else?

- Re-shape all tip diffraction generators like air data probes. This is not physically difficult but dangerous for avionics because they rely on CONSISTENT air data flow across their ports. Raw air data is not a problem but CONSISTENCY in receiving them is. Re-shaping the air data probes could adversely affect that availability, especially during maneuvers, and that will create all sorts conflicting flight control commands.

- Enclose all external stores and this includes re-designing the pylons as well. The enclosure must be RCS efficient. If they are to be retained instead of discard then it must be understood that they will affect aerodynamics and fuel, but the discard option must still be available for the pilot in the event his life depends on its ejection from the aircraft.

- Re-design the canopy. The cockpit is a well and it will create high EM resonance.

- Smooth out surface flow as much as possible. This is about small surface discontinuities that the closer they are to each other -- real estate wise -- the greater the odds of their diffracted/resonance cumulative effects be detected and focused upon by a seeking radar. This effect was easy to incorporated into all radar systems.

- Re-design the engine exhaust.

f-35_j-20_exh.jpg


Those 'saw tooth' patterns -- geometric absorber -- on the F-35's engine exhaust is actually more effective at scattering diffracted signals every which way but back to source direction than people realize. It is rare to look straight into an engine from the 'six' position so this technique is more effective than the simple straight edge to deny the seeking radar some energy. Not all, but enough. We have done plenty of model/predict and measurement on this.

So how much money will it take to do all of the above? No one really know. But if it approaches the point where it will cost to design 'stealth' from paper...Then is it worth it?
 
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Well making an aircraft stealthy is not a big deal but making an aircraft stealthy without compromising the performance parameters and keeping the costs the same is a huge deal.
 
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Giving it small tweaks is one thing, calling it stealth is another.

Sir,

"STEALTHIER" is the word---not STEALTH----thank you-----either in the form of radar absorbing paint scheme or panels made of composite material taken at the last oppurtune moment---.

It is going to happen---it should already be happening---it is already happening----when will it come out---. I tell you what---since I stopped the leakage of information on the JF 17---it will not come come out just like it used to.
 
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Interesting new pod. Posted by A.Man on CDF

3xeSQ.jpg


BuzNz.jpg

What is more interesting, is in the second picture. J-10A next to JF-17 which is then next to J-20. Future of Asian Airspace dominance? Future PAF? Interesting to see testing going on.

Also, notice the single piece canopy of J-20.
 
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JF-17 is proving to be a test bed for many of the Chinese new systems and sub systems, i wonder how many would actual make it to the JF-17 specially if we are going to see any thing past the KLJ-7 radar.
 
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Sir,

"STEALTHIER" is the word---not STEALTH----thank you-----either in the form of radar absorbing paint scheme or panels made of composite material taken at the last oppurtune moment---.

It is going to happen---it should already be happening---it is already happening----when will it come out---. I tell you what---since I stopped the leakage of information on the JF 17---it will not come come out just like it used to.

Hi, to add to Mr. MK's point. There is an article in the current issue of Air Forces Monthly on the evolution of the J-11. One interesting snippet of information was, that the J-11 has a RCS that is one fourth the size of the original Su-27 and also weighs less. This was accomplished by using RAM and composites.

Future incarnations of the JF-17 could easily leverage this technology.
 
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Just like the message above from Nabil, I have the same question. WHERE in ANY of my posts did I mention to turn JFT into Stealth?????? or that if we reduced the RCS, it'll become a stealth jet???

I think you oughta read what someone says, understand it and then counter the argument with yours. Burning cycles for the sake of argument is not really productive. I've mentioned many times, "Stealthy" does NOT equal to "Stealth". Please reread my posts, Nabil's, Gambit's and a few from Mastan Khan.

Then we are all on the same page.

Sometimes you did give the impression that you wanted to give it the term stealth. That is my opinion. oh well....
 
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IF the pic is not a photoshop, i suspect it is the new version of kg-300g pod that was mentioned last year by PAF personnel. look at the front end which seems changed but the rear portion is the same as original. Maybe a new version being tested?
 
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Where in my post did i say JFt can be converted into Stealth?? No need to put words in my mouth only to prove that you know it all because it is obvious you dont, in fact, no one does.

LOL, that was my point and it was a general statement. I only quoted you because you were talking about stealth and RCS reductions. I never stated that you said anything like that, but I can understand your reaction. :)

Measures have been taken and can be seen in the first block unless you deliberately ignore them to prove your two pennies.

Besides what you claim and the confusions about DSI, we have several senior Pakistani members here that confirmed that JFT currently don't use any RAM materials or coating, but this is one of the prime requirements to reduce the RCS of a non stealth fighter!
We also know that nearly the whole airframe was build with normal metal structures and not with more costly composites and again several senior Pakistani members confirmed that the ammount will be increased in Block 2 only to a very low ammount.
Now add 1 + 1 and you will understand that JF 17 block 1 logically might have a lower RCS than the older and bigger F16 Block 15s, but that it can't have a low RCS compared to modern designed fighters.
The use of DSI infact is very logical when you don't use RAM, because it deletes the air intake inlets, that would increase the RCS unless treated with RAM. Therefore DSI is a cost-effective way to counter this problem, while the main idea behind it is, increased engine performance not RCS.

As Oscar often tries to make clear here, the main idea behind JFT is heaving a cost-effective fighter that can be used in different roles and not a high end top of the line fighter!
Especially the early blocks therefor will have a focus on basic radar and avionics + weapon integration, while the Block 3 might bring JFT to a comparable 4.5 gen level, including techs, coatings, materials... The fact that PAF wants J10B as a topline fighter above JF 17, although both shares most of the radar, avionics and weapons, makes this clear as well, so I don't need it ignore anything, just to look at the reality of JF 17 and what PAF wants (which you can see when you follow this and the JF 17 info pool thread) to understand the differences.
 
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IF the pic is not a photoshop, i suspect it is the new version of kg-300g pod that was mentioned last year by PAF personnel. look at the front end which seems changed but the rear portion is the same as original. Maybe a new version being tested?

yeah .. who said its PS ... you can clearly see the POD in second pic as well under the J-20 nose.

BuzNz.jpg


Well, head of the POD seems like a Glass Bubble ... it is something new for sure :agree:
 
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