JF-17 Thunder Multirole Fighter [Thread 3]

[qsaark]

Yes it was a big leap but they weren’t just fresh academy graduates but all were well trained fighter pilots with each one of them having 1000s of hours under their belt.

What would prevent the same from happening for the future inductions?

 

[MastanKhan]

X-man,

Thankyou very much for your post. Indeed it is the biggest hurdle---integration.

Paf is in a heap of trouble today----young kids say that the jf 17 will come and do wonders---others say that BLK 52 will be invincible---others say that awacs will master the skies---other are confident that the tankers will turn things around---.

But none of them understand that how much does the paf has on its platter---the platter is overflowing and is barely being contained. Too much stuff is being put together at the same time---one big problem---one big mistake---and all of it will get stuck in the bottle neck.

If the french are true to their word---then it is not good for the jf 17---even though the chinese have a back up system----but we didnot want the backup system in the first place---now did we---.

You can't just put the pilot into one of these machines and ask him to go---it will take at least three to five years for them to excel at what they are doing---we know that---.

As you stated, the problem here is that the su 30 pilot has 10 plus years of flight experience on that bird---now as good a pilot that we may have, he can't jump into the jf 17 and do the tricks.

Old members would remember that many a times ( many a years ago ) I mentioned that to be a superstar fighter jock you would need around 5 to 10 years in the saddle of the F 16 in the 80's to stake your claim.

Now in the current discussion---just for the sake of discussion we agree that the su 30 pilot is a pro and so is the jf 17 pilot---now pitching the jf 17 against the su 30 is not being fair to my pilot---even though I know that he will do whatever it takes to lock and launch those sd 10's---even if it is a matter of split second before the russian bvr hits him---I know that there are some in the paf who look death in the eye to take that one shot.

Reading the responses, I am getting the feeling that some of the young readers are not understanding the physics of the distance of 90% kill range of either missile. I am not saying that as we know that their missile can take us out from far, so we should not do any thing.

What I am saying is understand your shortcomings and plan accordingly. Because until and unless you don't accept that there is a problem or an issue, how would you tackle it.

Again all the paf lovers---create a scenario----pakistan air force owns SU 30 MK P ( P for pakistan )---and IAF owns JF 17 .

And you indian colleagues---you own the jf 17 as it is---you know its specs---it is your job to pitch that plane against the pakistani su 30---.

Indians are going to pitch for the jf 17 and pak are going to pitch for the su 30---let us what happens.

 

[wangrong]

x_man,

Thanks for elaborating on this unique aspect that most of the members missed here.

I have a question about J-10s performance. Right now 4 of them have crashed and I imagine only 20s of those would be in the Chinese air-force by now. What do you think about performance of J-10s and how much weight can we put on this aircraft for the National Defense?

bcz Engine quality

 

[ptldM3]

bcz Engine quality

This is hard to beleive considering the SU-27/30 have an outstanding safety record, one might argue that a twin engine aircraft are safer but that's not always the case, i have been in an aircraft where the right engine was shut off during training and the aircraft veired to the right and lost altitude. Most crashes also happen after take off which even if it was an engine failure the aircraft would still likely crash as evident to the 1993 crash of a Mig-29 after a bird strike, this is important because it proves two things, one that aircraft typically experience engine failures after take off and two, even twin engine aircraft such as SU-27 crash if they have an engine failure at low altitude, so this just proves that blaming the AL-31 for the J-10 crashes should be taken with a truck load of sault. I can except that one engine failure is possible, i can even except two but when four aircraft crash and the Chinese authorities blame it all on an othwise safe engine than something is wrong.

The AL-31 had been in service for decades, so a design flaw can be ruled out. The following are reasons why J-10 could have crashed:

Design flaws
anomolies such as bird strikes
poor maintanance
pilot error
poor weather

All are very possible accept for design flaws because as i pointed out earlier the AL-31 has been in service for decades and as such all defects would be addressed by now.

Several weeks ago speculated the J-10 crashes were due to poor quality control and assembly from the factories, i stated that if the engine isn't properly fasened to the engine mounts than things such as vibrations can accure, and if vibrations accure parts such as fuel lines, hoses and wires can come loose and seperate do to fatigue. Today, it turned out that my speculation could have some truth behind it because J11B' are having issues with vibrations--this could be the WS-10 or it could be poor quality assembly which is what i'm leaning towards.


Another highly probably reason could be poor maintanace, you see if the ground crew misses something as simple as a bolt the entire aircraft can crash and that precisely what happened to an F-117. Another thing to consider is that the J-10s were fitted with the WS-10, if this was the case, i'm not saying that it's a bad engine but rather that it is a new engine thats still not fully mature.

 

[SomeGuy]

Over here neither there is numerical superiority, nor there is an air to air superiority---an su 30 can carry 8 bvr's---the jf 17 can only carry 2---an su 30 can see and act from a farther distance with immunity

The JF-17 has 7 hardpoints - so why only carry 2 BVR's???
You must be thinking about the fire-control radar only being able to engage 2 targets.

The su 30's bvr's have a better killing range than the sd 10---it can get closer into the 90% killing range and fire multiple missile at the same target before the jf 17 can get within the 90% kill range of the sd 10---the su 30 can then turn around and scoot---the jf 17 may not even have the chance to fire at 90 % kill range.

In a similiar manner---the Su 30 mkI has bvr's that have a longer range than the future sd 10 of paf.

Tha max range of the russian bvr is around 100 km---the max range of sd 10 is around 60 km----the 90 % kill range of russian bvr is around 50--60 km---the 90% kill range of sd 10 is around 30 to 40 km if it is.

I seen many different figures for the performance specs of these missles on the internet that I don't know which to believe.

One site (Sinodefence) has the following figures for PL12/SD-10 and R-77. Chinese use both of these so I would probably say that these are more credible.

PL-12/SD-10:

Max speed: Mach 4
Max range: 50~70km
G Limit: 38g

R-77:

Max speed: Mach 3
Max range: 50~80km
G Limit: 12g

So if this data is correct, then both missiles seem to be fairly even. The R-77 does have slightly more range but the SD-10 is faster and more agile.

As for radars:

I've seen figures for the KLJ-7 as 75km for a target of 3m2 - this would obviously increase for a target as large as an MKI.

Assume MKI RCS ~15m2,
Using Situation Awareness equation (RCS1/RCS2)^0.25......
JF-17 could detect MKI at 112km.

Conversely,

I've seen figures for the NIIP N011M Bars as 140-160km for a F-16 sized target.

The question now is "which F-16?" - Older ones are about 5m2, modern ones are around 1m2.

Assume it's 5m2 (since that's what Russians usually use anyway)
Also, assume JF-17 RCS is 1-2m2
Using same equation above.....
MKI could detect JF-17 at between 107-127km.

So radar detection is about roughly equal given their different sizes and become less relevant when AWACS/AEW is used.

 

[wangrong]

This is hard to beleive considering the SU-27/30 have an outstanding safety record, one might argue that a twin engine aircraft are safer but that's not always the case, i have been in an aircraft where the right engine was shut off during training and the aircraft veired to the right and lost altitude. Most crashes also happen after take off which even if it was an engine failure the aircraft would still likely crash as .

Engine inflight shutdown

 

[ptldM3]

Engine inflight shutdown

Like i mentioned the AL-31 just doesn't shut down, something has to cause it to shut down, something like improper maintanace, or it can shutdown because something like a fuel line comes loose because of improper instalation from the factory which may cause vibrations, something that has already been reported in the J-11B. Again AL-31 don't have any design flaws and they have a good safety record, if J-10s are crashing the burden in on the maintanaince crew and the factory QC.

 

[Guest]

bcz Engine quality

only one was known as engine failure, the others ramian unknown. J-10 was designed to be static instable to gain maximum maneuverability. so it needs FBW system to compensate the static instability. for JF-17 or Su-27, they could still ramain flyable even if their FBW system failed; but a J-10 will fall in such cases.

however, considering that there were more then 250 Class A accidents happened in the first 10 year of the F-16 history. 4 clashes in 4 year, if it is ture, is still a accaptable figure.

i don't know how US define Class A accident, but in China Class A accident means lost of human life or personal serious hurt or lost of equipment.

 

[Guest]

a missiles' non-escapable zone (NEZ) various from situation to situation.

if your target can turn and run fast, the NEZ decreased;
if you are shooting up, the NEZ decreased;
if you are shooting down, the NEZ will increase. but if you are shooting too low, the missile will put on too much speed and will miss its target more easily.
and wind, altitude, humidity etc will also affect that.

 

[jagjitnatt]

One site (Sinodefence) has the following figures for PL12/SD-10 and R-77. Chinese use both of these so I would probably say that these are more credible.

PL-12/SD-10:

Max speed: Mach 4
Max range: 50~70km
G Limit: 38g

The above figure of 38g is simply not possible. No A2A missile in the world can achieve that. Definitely not with simple fins.

R-77:

Max speed: Mach 3
Max range: 50~80km
G Limit: 12g

Range of R77 is 90 kms.

So if this data is correct, then both missiles seem to be fairly even. The R-77 does have slightly more range but the SD-10 is faster and more agile.

As I said the above data for SD-10 has been highly inflated to unimaginable figures. The R-77 is the most agile missile (medium range) in the world right now due to its lattice control surface.

As for radars:

I've seen figures for the KLJ-7 as 75km for a target of 3m2 - this would obviously increase for a target as large as an MKI.

Assume MKI RCS ~15m2,
Using Situation Awareness equation (RCS1/RCS2)^0.25......
JF-17 could detect MKI at 112km.

The rcs of MKI is almost 15 square meter with all weapons loaded, similarly the rcs of JF-17 would also shoot up with the weapons.
MKI would detect a 3 square meter rcs aircraft at a distance of 166 km.
There is no way you can calculate the range at which KLJ-7 would detect MKI, since not much info is available, but 100 kms seem to be the number.

Conversely,

I've seen figures for the NIIP N011M Bars as 140-160km for a F-16 sized target.

The question now is "which F-16?" - Older ones are about 5m2, modern ones are around 1m2.

Assume it's 5m2 (since that's what Russians usually use anyway)
Also, assume JF-17 RCS is 1-2m2
Using same equation above.....
MKI could detect JF-17 at between 107-127km.

As I said above, MKI detection ranges are:

5 m2 = 194 km
3 m2 = 166 km
1 m2 = 135 km

The rcs of JF-17 is not 1 m2, but much more than that, since it doesn't employ any rcs reducing features. There are no composites, no ram, even the canopy is not rcs reducing. Its rcs is gonna be higher than 3 m2 according to me, somewhere in the range of 3 m2 to 5 m2.

So radar detection is about roughly equal given their different sizes and become less relevant when AWACS/AEW is used.

Answered above.

 

[ptldM3]

Range of R77 is 90 kms.

The R77M1 has a range of 175km; however, i'm not sure if India has it.

Sorry i know it's off topic.

 

[jagjitnatt]

The R77M1 has a range of 175km; however, i'm not sure if India has it.

Sorry i know it's off topic.

Yes, I don't think its operational and there's almost no info available on it.

 

[gambit]

only one was known as engine failure, the others ramian unknown. J-10 was designed to be static instable to gain maximum maneuverability. so it needs FBW system to compensate the static instability. for JF-17 or Su-27, they could still ramain flyable even if their FBW system failed; but a J-10 will fall in such cases.

Not necessarily.

JF-17 Thunder - Wikipedia, the free encyclopedia

The aircraft has a composite flight control system (FCS), comprising conventional controls with stability augmentation in the yaw and roll axis and a digital fly-by-wire (FBW) system in the pitch axis.

Pitch axis instability is the main factor in increasing maneuverability as the aircraft nears high subsonic and passes into the supersonic region. Failure in this system will most likely render the aircraft unflyable. When the system is called 'quadruple redundant', at the very least, it mean a data input, electrical or air, is divided into four separate channels and a voting process takes place. More sophisticated designs will have four distinct inputs, in other words, instead of dividing a single pitch rate gyro signal into four, there would be four pitch rate gyro signals from four distinct gyros inside the pitch rate gyro assembly. Same for roll, yaw and the accelerometers. For mechanical-hydraulics FLCS, three inputs are adequate for the voting process.

Anyway...In any of the voting processor, if there is an 'even' number of inputs, the system will consider that axis compromised and will trigger a warning. Now...People would question then why is there a 'quad', an even number of inputs -- 4. The answer is that the voting processor will examine all four inputs, select the best three signals that are closest to each other, then compute the best control signal from these three to send to the hydraulic actuator. The fourth signal is basically held in reserve. General Dynamics, analog F-16, found this arrangement the best in terms of FLCS signal integrity versus weight and power demands and so on. If there are only three inputs for the voting processor and if one is found to be out of a specified tolerance, the system have no reserve. For the 'quad' design, the examination, selection and voting process takes place continuously throughout flight. Is it possible that one signal is always rejected? Yes..But keep in mind that for this design, a 'rejected' signal may not be out of tolerance. A genuinely rejected signal would be out of tolerance and the FLCS computer would trigger a warning. The cause could be from many factors: the gyro, the FLCS computer, the wire harness that contain the specific wire, the list is considerable. The result is that you have a problematic line-replaceable-unit (LRU) that you can track pitch axis problem from aircraft to aircraft (scary). Or you can make the aircraft a 'hangar queen' and assign your best techs to troubleshoot.

however, considering that there were more then 250 Class A accidents happened in the first 10 year of the F-16 history. 4 clashes in 4 year, if it is ture, is still a accaptable figure.

i don't know how US define Class A accident, but in China Class A accident means lost of human life or personal serious hurt or lost of equipment.

No different...

warning

A Class A accident is an accident that results in fatality or total permanent disability, loss of an aircraft, or property damage of $2 million or more.

When there is the world's largest air force with the most diverse aircraft inventory, no reason not to emulate and save yourself a lot of work in setting standards.

 

[Guest]

Not necessarily.

JF-17 Thunder - Wikipedia, the free encyclopedia

1) the FBW system used in JF-17 is only a dual-redundant system, not quadruple redundant.

2) no matter how many redundant, there will be only one finnal output made by only one computer if not all the outputs are not identical. besides that, it is possible that all the redundant systems will make an incorrect but identical decision base on one or more incorrect inputs. so if this output is incorrect, there is nothing the pilot could do except to restart or turn off the FBW system.

3)as JF-17 is not a static instable plane, the AC won't tumble from the sky even the FBW is swith off. so the pilot may have much longer time, compared to that of a J-10's pilot, to fix the problem.

 

[gambit]

1) the FBW system used in JF-17 is only a dual-redundant system, not quadruple redundant.

I think you have the wrong context of 'redundant'...

JF-17 Thunder - Wikipedia, the free encyclopedia

The aircraft has a composite flight control system (FCS), comprising conventional controls with stability augmentation in the yaw and roll axis and a digital fly-by-wire (FBW) system in the pitch axis. The leading edge slats/flaps and trailing edge flaps are adjusted by the flight control system automatically during manoeuvring to increase turning performance.[6] Some sources state that the system has been upgraded to provide fly-by-wire flight control in the roll and yaw axis also, the serial production aircraft having a digital quadruplex (quad-redundant) FBW system in the pitch axis and duplex (dual-redundant) FBW system in the roll and yaw axis.

I am willing to guess that for the pitch axis, which is a pure fly-by-wire axis, the pitch axis is quad redundant. For the roll and yaw axis, since they are mechanical-hydraulics, their commands would be augmented by triple-redundant electrical signals, hence the phrasing 'dual redundancy'.

2) no matter how many redundant, there will be only one finnal output made by only one computer if not all the outputs are not identical. so if this output is incorrect, there is nothing the pilot could do except to restart or turn off the FBW system.

Not for pitch.

3)as JF-17 is not a static instable plane, the AC won't tumble from the sky even the FBW is swith off. so the pilot may have much longer time, compared to that of a J-10's pilot, to fix the problem.

For any fly-by-wire axis, there is no turning 'off' the system. Unless you call a crash a 'turn off' switch.