JF-17 Thunder Multirole Fighter [Thread 5]

[Side-Winder]

Look forward to what? It looks like a regular JF-17 with camo. Am I missing something?

it's supposed to be azerbaijan's flag

 

[Chak Bamu]

Sir by your post what I understand, its not financially & technically worthwhile to incorporate stealthy features in JF-17 fuselage, but any effort on subsystems (Fuel Tank & Missile armament) could be helpful ...... so we should work on the designs of external fuel tanks and air to air missiles which contribute a hefty share in aircraft's RCS.

Actually @gambit has made a very comprehensive post on the subject of stealth. He is talking from a US perspective, while we here in Pakistan know that we can not quite measure up to VLO stealth.

There are three things that need to be considered:

1. Adversary & its weapns.

2. Missiles to be carried.

3. Tactics to be employed based on respective strengths and weaknesses.

The level of Low Observability practically achievable and therefore desirable within resource constraints can be determined in light of the above factors. Perhaps we are at a level where we need not obsess about JF-17's observability considering Indian combat aircraft and missiles. But we can not be totally sure, and therefore each upgrade ought to make some incremental improvement in this regard.

We can not make massive modifications to the airframe. That would be like designing a brand new aircraft. We can attempt doing it, but do we have the technology or the resources?

 

[HRK]

We can not make massive modifications to the airframe. That would be like designing a brand new aircraft. We can attempt doing it, but do we have the technology or the resources?

Exactly for this reason I enquired, in his post @gambit Sir hinted about the alternative steps, which I may have understand wrongly ..... as it is being said by some senior members previously that clean JF-17 have the least RCS value in PAF inventory, but as a general phenomena aerial armaments & fuel Tanks increase the RCS of aircraft ...... and gambit Sir said "The bottom line is that EVERYTHING on the aircraft must be subjected to the three steps dictated by RCS control philosophy"

Therefore keeping our abilities, knowledge, and limited resources in mind I agree that its not financially and technically feasible to redesign an operational aircraft for low observability, but my question is would it be beneficial in financial and technical terms to redesign external fuel tanks and armaments for stealth or low observability to reduce RCS of fully loaded JF-17..... ??

 

[Thorough Pro]

one. I have not and am not insulting anyone here.

Second, you are talking out of patriotism only, What experience do Pakistani Engineers have of ever designing, developing, or manufacturing any radar? except for maintenance/overhaul of foreign radars for which PAF/PAC were totally dependent on both equipment and training by foreign OEM's. There is a huge difference in building something from zilch (Design, Develop, manufacture, test, debug, etc...) and assembling imported kits.

If Chinese knew nothing of radars, then did Pakistan supplied them the same for all Chinese platforms?

China is catching up fast with the western world and you are telling me that they nothing about radars? why did we bought ZDK03 from them then?

Patriotism is good, realism is best. Be thankful to China for proving all the military stuff that we have, other-wise we were not even capable to equip our forces with home grown sling-shots.

maybe you should stop insulting Pakistani enginners work any leadership in this project…
Chineese were nowhere near West in radar tech and weapons tech if you neglect pak role then maybe thinge wouldnot be like that especially for JF-17 in yerm of chineese avionics,HMDS and radar technology…

You know the relationship between a customer and a tailor? customer tells what he wants to wear and tailor stitches that, now by your logic the credit for good stitching should go to the customer.

maybe you should stop insulting Pakistani enginners work any leadership in this project…
Chineese were nowhere near West in radar tech and weapons tech if you neglect pak role then maybe thinge wouldnot be like that especially for JF-17 in yerm of chineese avionics,HMDS and radar technology…

 

[Gentelman]

one. I have not and am not insulting anyone here.

Second, you are talking out of patriotism only, What experience do Pakistani Engineers have of ever designing, developing, or manufacturing any radar? except for maintenance/overhaul of foreign radars for which PAF/PAC were totally dependent on both equipment and training by foreign OEM's. There is a huge difference in building something from zilch (Design, Develop, manufacture, test, debug, etc...) and assembling imported kits.

If Chinese knew nothing of radars, then did Pakistan supplied them the same for all Chinese platforms?

China is catching up fast with the western world and you are telling me that they nothing about radars? why did we bought ZDK03 from them then?

Patriotism is good, realism is best. Be thankful to China for proving all the military stuff that we have, other-wise we were not even capable to equip our forces with home grown sling-shots.





You know the relationship between a customer and a tailor? customer tells what he wants to wear and tailor stitches that, now by your logic the credit for good stitching should go to the customer.

try to have a discussion with chineese on this matter and Pak build Griffo radars under TOT yeah they didnot designed……
in JF-17 production Pak enginniers were equally involved and worked with em……
and if you teach someone how to stitch rather than just telling what he want then you are not customer you are an institute……
PAF and PAC has a long history with avionics and radars on platfirms like F-7s and Mairages and PAC even upgraded F-16s engine indegiously if you ever had time to check it out……
and I am not talking about 2013,fiscussion is before Lavi progect transformation in J-10 before 1990s……

 

[gambit]

Sir by your post what I understand, its not financially & technically worthwhile to incorporate stealthy features in JF-17 fuselage, but any effort on subsystems (Fuel Tank & Missile armament) could be helpful ...... so we should work on the designs of external fuel tanks and air to air missiles which contribute a hefty share in aircraft's RCS.

First...Yes, it is true that all the external doo-dads greatly contribute to RCS.

The current standard for most radar systems, civilian and military, is that for ANY given X distance, say 100 km for example, if the system determined that it is 80% certain that there is a one-meter square body in its view, it will flag that body as a valid target.

That DOES NOT mean an object have a fixed RCS of one meter/sq2. In radar detection, no object ever does have a fixed RCS. Most people have a misunderstanding of this 'one meter square' figure and how it came to be. It means the object:

- appears...
- seems...
- perceived...
- thought...
- idealized...
- speculated...

...To be one meter/sq2 with 80% probability at X (100 km example) distance.

If a B-52 is at 100 km distance, more likely it will be perceived to be 1,000,000% certain that it is one meter/sq2. So how do we get the B-52 to be one meter/sq2 at 80% certainty? May be moving it all the way back to 500 km distance? Am just throwing out rough figures for illustration purposes.

Now...What happens if we load our F-16 with a 'typical' strike weapons load out of:

F-16A/C "Fighting Falcon"

How about 100% of this object being one meter/sq2 at 200 km distance? That is how 'bad' it get with external stores. Of course, if all we have a belly fuel tank and a load of beam rider missiles to hit ground radar stations, then may be we shorten that distance to 170-180 km.

The reason why engineers came to the agreement -- and it is an unofficial agreement -- of 80% certainty is that by the time the object is perceived to be one meter/sq2, it would have passed through most environmental factors such as hydrometeors or stray radiation from elsewhere that could induce ambiguity into data processing. Can I lower that threshold? Absolutely and I have done it when I used to design field tests. I have told my test system to alert me when it perceived an object to be one meter/sq2 when it is 50% certain. The result was that I ended up chasing a lot of ghosts. I have also rigged my test system to alert me at 80% certainty of 10 meter/sq2. The result was that I was 'killed' by the time the system flagged the attacker.

An attacker can fly below the radar horizon for a while, then perform a 'pop up' maneuver to acquire a ground target and to bomb toss. At that moment, the attacker will be perceived to be 100 meter/sq2 at 100% certainty. Of course, by that time, the bombs would have been tossed, and probably each bomb will be perceived to be one meter/sq2 at 100% certainty.

I hope that this will settle any confusion on how/why we use that one meter/sq2 figure so often.

Anyway...For the JF-17...You must perform baseline radar measurement of a clean aircraft at different distances to see which X distance is when a radar system will flag it as one meter/sq2 with 80% certainty. Most airborne combat radar systems in the 'fighter' class will be in the X-band so your test system must be in the X-band. That does not mean you cannot radar measure using an AWACS class freq. You certainly can and it would be helpful later on in analyzing different combat scenarios, but this would be an entirely different discussion and I WILL NOT go there. You guys can speculate all you want for that.

Then once you have that baseline figure, you can begin to whittle away at the aircraft, virtually, of course, with 2 of the 3 steps of RCS control:

- Prediction
- Modeling

You can do this just for frontal RCS alone, if you wish, and let us assume that is your goal -- frontal.

In this program, you must have 'milestone' points, meaning these are where you must stop and take measurements. You predict that if you trim the radome a little bit here, modify the canopy structure, and install a bit of absorbers at the intake lips, your model should have a .25 decibel reduction at ANY distance for a given freq, which is the X-band for now.

Now you must take a real aircraft and modify it according to this milestone and measure it. Assume that you are successful.

Now you predict that if you coat the canopy, coat the intake tunnels with absorbers, and install absorbers at the wing leading edges, your modeling should yield an additional .10 decibel reduction for a total of .35 reduction from base, also at any distance for a given freq, which should remain as X-band.

Now you must take your modified aircraft and modify it again according to this milestone and measure it. What if your measurement failed to meet expectation? What if it exceeded it?

Say your final goal is to have a frontal RCS of one meter/sq2 of 80% certainty at 50km distance.

Say your bomb toss technique is so good that you are pinpoint accuracy at 50km distance out. One bomb after another from a single aircraft.

This is why your final goal -- measurement -- is a frontal RCS of one meter/sq2 of 80% certainty at 50 km distance for a clean fighter so that when it is loaded, it will be one meter/sq2 of 80% certainty at 100 km distance, which at that point you can bomb toss and get out of the area.

But what if your modified aircraft failed to meet a milestone towards what final goal?

This is an example of how a tactical combat desire drives a technical program on an existing platform. It does not have to be in radar alone. GPS guidance drove many technical changes to existing platforms. Same for real time satellite feeds for any information.

So for your JF-17 in this hypothetical scenario, because you perfected a combat technique and want to exploit it to the fullest, you created a tactical combat goal, which is a gross reduction in effective radar detection distance by an enemy, and now you must modify an existing platform so that you can exploit your new capability.

But what if for all your work, and only in frontal RCS alone, your measurements of your aircraft consistently failed to meet milestones? Would it be any good to modify external stores at all? Perhaps some good may come out of them since if individually all of them met or exceeded their milestones and therefore would contribute less to total RCS.

Say that despite your best efforts, your modified JF-17 persists in having a frontal clean RCS of one meter/sq2 at 70 km. It used to be 100 km for a clean jet, remember? You failed to meet your goal of 50 km, but at least you did achieved a reduction of 30 km. That is not a bad achievement. It used to be that for a fully loaded JF-17, it was detected at 200 km. Now with a modified JF-17 loaded with modified external stores, instead of your desired goal of 100 km, may be it is somewhere between 130-140 km? Not bad at all. May be instead of bomb toss at 100 km and escape confident that your targets will be destroyed, you may have to devise additional combat tactic to make up for that 30-40 km that you failed to meet in trying to modify your fighter.

You must understand that in this endeavor, you WILL take several fighters out of active duty and essentially ruin them for good in trying to meet this goal and with no guarantees you will succeed at that.

What if you modify external stores alone, would their contributions be reduced enough to meet 150 km distance goal? May be. But even if you do not intend to modify the fighter, it would still be extremely helpful in know its share of total RCS to help guide your modifications of external stores. Remember, your new tactical capability is pinpoint accuracy at 50 km bomb toss distance. If your clean fighter is detectable at 150 km distance, modification of external stores would not be financially worthwhile, even if they came to contribute zero percent. Your fighter is just simply detected too far away for you to exploit your new combat capability.

Modifying an existing platform is actually more than just modifying the delivery vehicle. A 'fighter' is composed of a delivery vehicle and a bunch of stuff that can destroy other stuff. This is why Pakistan should have technical parity with the likes of Boeing or MD to try.

 

[alimobin memon]

AOA , Just came to know that many of guys on internet think that jf17 can't do vertical climb. If it doesn't is it useless claim it had good results against j11 of china in exercises as claimed by chief ? I mean I do believe it does Climbing. But if I am wrong correct me .

 

[Side-Winder]

AOA , Just came to know that many of guys on internet think that jf17 can't do vertical climb. If it doesn't is it useless claim it had good results against j11 of china in exercises as claimed by chief ? I mean I do believe it does Climbing. But if I am wrong correct me .

Yes Vertical climb performance is not quite up to the mark,
performing good against J-11 doesn't mean JFT might have completely defeated them...

 

[alimobin memon]

That's what I said good results not Excellent or perfect . it has 270m/s I think So it means it does have it thanks

 

[Thorough Pro]

PAC upgraded F100 engines in-house after P&W provided the upgrade kits and the equipment and training...that is not called "indigenously" maybe you need to look up the meaning of indigenous.


You can only teach to others that you know and have demonstrated the skills.............now which Radar or avionics did Pakistan ever made which made them teachers? just using the equipment does not makes one expert in its manufacture also.

try to have a discussion with chineese on this matter and Pak build Griffo radars under TOT yeah they didnot designed……
in JF-17 production Pak enginniers were equally involved and worked with em……
and if you teach someone how to stitch rather than just telling what he want then you are not customer you are an institute……
PAF and PAC has a long history with avionics and radars on platfirms like F-7s and Mairages and PAC even upgraded F-16s engine indegiously if you ever had time to check it out……
and I am not talking about 2013,fiscussion is before Lavi progect transformation in J-10 before 1990s……

 

[Gentelman]

PAC upgraded F100 engines in-house after P&W provided the upgrade kits and the equipment and training...that is not called "indigenously" maybe you need to look up the meaning of indigenous.


You can only teach to others that you know and have demonstrated the skills.............now which Radar or avionics did Pakistan ever made which made them teachers? just using the equipment does not makes one expert in its manufacture also.

provide link to prove your claim?
you just needs to ask some chineese about that dude rather than this BS of degrading your own institutes……
and you also needs to check out Rashid Latif interview to the Airforce monthly mag……

 

[Thorough Pro]

You want me to provide links and proof, and to verify your claims I should ask Chinese. LOL

and btw talking about facts in not degrading and boasting is not patriotism.....be realistic, positive and critical

provide link to prove your claim?
you just needs to ask some chineese about that dude rather than this BS of degrading your own institutes……
and you also needs to check out Rashid Latif interview to the Airforce monthly mag……

 

[Gentelman]

You want me to provide links and proof, and to verify your claims I should ask Chinese. LOL

and btw talking about facts in not degrading and boasting is not patriotism.....be realistic, positive and critical

whatever
I just said you couldnot neglect Pakistan's role in chineese Airforce development……
Just reality

 

[satishkumarcsc]

First...Yes, it is true that all the external doo-dads greatly contribute to RCS.

The current standard for most radar systems, civilian and military, is that for ANY given X distance, say 100 km for example, if the system determined that it is 80% certain that there is a one-meter square body in its view, it will flag that body as a valid target.

That DOES NOT mean an object have a fixed RCS of one meter/sq2. In radar detection, no object ever does have a fixed RCS. Most people have a misunderstanding of this 'one meter square' figure and how it came to be. It means the object:

- appears...
- seems...
- perceived...
- thought...
- idealized...
- speculated...

...To be one meter/sq2 with 80% probability at X (100 km example) distance.

If a B-52 is at 100 km distance, more likely it will be perceived to be 1,000,000% certain that it is one meter/sq2. So how do we get the B-52 to be one meter/sq2 at 80% certainty? May be moving it all the way back to 500 km distance? Am just throwing out rough figures for illustration purposes.

Now...What happens if we load our F-16 with a 'typical' strike weapons load out of:

F-16A/C "Fighting Falcon"

How about 100% of this object being one meter/sq2 at 200 km distance? That is how 'bad' it get with external stores. Of course, if all we have a belly fuel tank and a load of beam rider missiles to hit ground radar stations, then may be we shorten that distance to 170-180 km.

The reason why engineers came to the agreement -- and it is an unofficial agreement -- of 80% certainty is that by the time the object is perceived to be one meter/sq2, it would have passed through most environmental factors such as hydrometeors or stray radiation from elsewhere that could induce ambiguity into data processing. Can I lower that threshold? Absolutely and I have done it when I used to design field tests. I have told my test system to alert me when it perceived an object to be one meter/sq2 when it is 50% certain. The result was that I ended up chasing a lot of ghosts. I have also rigged my test system to alert me at 80% certainty of 10 meter/sq2. The result was that I was 'killed' by the time the system flagged the attacker.

An attacker can fly below the radar horizon for a while, then perform a 'pop up' maneuver to acquire a ground target and to bomb toss. At that moment, the attacker will be perceived to be 100 meter/sq2 at 100% certainty. Of course, by that time, the bombs would have been tossed, and probably each bomb will be perceived to be one meter/sq2 at 100% certainty.

I hope that this will settle any confusion on how/why we use that one meter/sq2 figure so often.

Anyway...For the JF-17...You must perform baseline radar measurement of a clean aircraft at different distances to see which X distance is when a radar system will flag it as one meter/sq2 with 80% certainty. Most airborne combat radar systems in the 'fighter' class will be in the X-band so your test system must be in the X-band. That does not mean you cannot radar measure using an AWACS class freq. You certainly can and it would be helpful later on in analyzing different combat scenarios, but this would be an entirely different discussion and I WILL NOT go there. You guys can speculate all you want for that.

Then once you have that baseline figure, you can begin to whittle away at the aircraft, virtually, of course, with 2 of the 3 steps of RCS control:

- Prediction
- Modeling

You can do this just for frontal RCS alone, if you wish, and let us assume that is your goal -- frontal.

In this program, you must have 'milestone' points, meaning these are where you must stop and take measurements. You predict that if you trim the radome a little bit here, modify the canopy structure, and install a bit of absorbers at the intake lips, your model should have a .25 decibel reduction at ANY distance for a given freq, which is the X-band for now.

Now you must take a real aircraft and modify it according to this milestone and measure it. Assume that you are successful.

Now you predict that if you coat the canopy, coat the intake tunnels with absorbers, and install absorbers at the wing leading edges, your modeling should yield an additional .10 decibel reduction for a total of .35 reduction from base, also at any distance for a given freq, which should remain as X-band.

Now you must take your modified aircraft and modify it again according to this milestone and measure it. What if your measurement failed to meet expectation? What if it exceeded it?

Say your final goal is to have a frontal RCS of one meter/sq2 of 80% certainty at 50km distance.

Say your bomb toss technique is so good that you are pinpoint accuracy at 50km distance out. One bomb after another from a single aircraft.

This is why your final goal -- measurement -- is a frontal RCS of one meter/sq2 of 80% certainty at 50 km distance for a clean fighter so that when it is loaded, it will be one meter/sq2 of 80% certainty at 100 km distance, which at that point you can bomb toss and get out of the area.

But what if your modified aircraft failed to meet a milestone towards what final goal?

This is an example of how a tactical combat desire drives a technical program on an existing platform. It does not have to be in radar alone. GPS guidance drove many technical changes to existing platforms. Same for real time satellite feeds for any information.

So for your JF-17 in this hypothetical scenario, because you perfected a combat technique and want to exploit it to the fullest, you created a tactical combat goal, which is a gross reduction in effective radar detection distance by an enemy, and now you must modify an existing platform so that you can exploit your new capability.

But what if for all your work, and only in frontal RCS alone, your measurements of your aircraft consistently failed to meet milestones? Would it be any good to modify external stores at all? Perhaps some good may come out of them since if individually all of them met or exceeded their milestones and therefore would contribute less to total RCS.

Say that despite your best efforts, your modified JF-17 persists in having a frontal clean RCS of one meter/sq2 at 70 km. It used to be 100 km for a clean jet, remember? You failed to meet your goal of 50 km, but at least you did achieved a reduction of 30 km. That is not a bad achievement. It used to be that for a fully loaded JF-17, it was detected at 200 km. Now with a modified JF-17 loaded with modified external stores, instead of your desired goal of 100 km, may be it is somewhere between 130-140 km? Not bad at all. May be instead of bomb toss at 100 km and escape confident that your targets will be destroyed, you may have to devise additional combat tactic to make up for that 30-40 km that you failed to meet in trying to modify your fighter.

You must understand that in this endeavor, you WILL take several fighters out of active duty and essentially ruin them for good in trying to meet this goal and with no guarantees you will succeed at that.

What if you modify external stores alone, would their contributions be reduced enough to meet 150 km distance goal? May be. But even if you do not intend to modify the fighter, it would still be extremely helpful in know its share of total RCS to help guide your modifications of external stores. Remember, your new tactical capability is pinpoint accuracy at 50 km bomb toss distance. If your clean fighter is detectable at 150 km distance, modification of external stores would not be financially worthwhile, even if they came to contribute zero percent. Your fighter is just simply detected too far away for you to exploit your new combat capability.

Modifying an existing platform is actually more than just modifying the delivery vehicle. A 'fighter' is composed of a delivery vehicle and a bunch of stuff that can destroy other stuff. This is why Pakistan should have technical parity with the likes of Boeing or MD to try.

Sir you forgot to add about the altitude differences and ground clutter affecting the RCS. And also please explain about gain and loss in the radar antenna. Will be more helpful.

AOA , Just came to know that many of guys on internet think that jf17 can't do vertical climb. If it doesn't is it useless claim it had good results against j11 of china in exercises as claimed by chief ? I mean I do believe it does Climbing. But if I am wrong correct me .

It can do a vertical climb. But we have not seen it complete a vertical loop.

 

[DANGER-ZONE]

Bhai loog, summer is about to end we haven't seen any JFT with refueling probe let alone the mid air refueling.