PAF and the JXX Fifth Gen Fighter

[jagjitnatt]

Uh gambit.. would not the newer generation IR seekers that pick up the heat at the leading edges and in some cases the complete airframe itself..ala.. Python 5...or 9x..negate the IR suppression advantage??

IR suppression is not very effective as of yet.
Reason being that almost all IR missiles are short range missiles, and if an IR missile is being launched from 10-15 kms, there is little to nothing you can do to suppress the IR signature of the aircraft. The seeker will find the aircraft.

The only chance is to outmaneuver the missile or use of flares. We know how tough is it to outmaneuver a heatseeking missile. So flares remain the only option.

No matter how much you reduce the IR signature, you can not decrease it to the levels where the IR seeker fails to recognize the plane.

All that fuel being burnt, all that energy being generated has to have a signature. Maybe in future we might find a way to reduce it or make it less evident from certain angles, but nothing as of yet.

 

[SQ8]

IR suppression is not very effective as of yet.
Reason being that almost all IR missiles are short range missiles, and if an IR missile is being launched from 10-15 kms, there is little to nothing you can do to suppress the IR signature of the aircraft. The seeker will find the aircraft.

The only chance is to outmaneuver the missile or use of flares. We know how tough is it to outmaneuver a heatseeking missile. So flares remain the only option.

No matter how much you reduce the IR signature, you can not decrease it to the levels where the IR seeker fails to recognize the plane.

All that fuel being burnt, all that energy being generated has to have a signature. Maybe in future we might find a way to reduce it or make it less evident from certain angles, but nothing as of yet.

Considering that the newer seekers are fairly resistant to being decoyed by even the more intense flares.. It is quite likely that maneuverability will soon take a backseat when it comes to the close in knife fights..
even then.. high instantaneous turn rates will matter more I suppose..
the first shot being the one that matters..
With almost all new combat aircraft armed with HMS... the idea of having to fight WVR would be dangerous for anybody.

 

[jagjitnatt]

Considering that the newer seekers are fairly resistant to being decoyed by even the more intense flares.. It is quite likely that maneuverability will soon take a backseat when it comes to the close in knife fights..
even then.. high instantaneous turn rates will matter more I suppose..
the first shot being the one that matters..
With almost all new combat aircraft armed with HMS... the idea of having to fight WVR would be dangerous for anybody.

Yes. High instantaneous turns can defeat a missile in some cases.

Also I'd like to say that flares aren't outdated yet. A couple of flares can be distinguished from an aircraft. But a wall of flares can not be distinguished by a seeker. So if an aircraft launches a lot of flares, and uses those flares as a wall between the aircraft and the missile, it might lose the missile easily.

Dogfights are going to get deadly in the future, its no longer the time when you could tail another aircraft for minutes before taking it down. Its only a matter of seconds these days, and most of the times, the opponent gets destroyed before entering visual range.

 

[Thomas]

Yes. High instantaneous turns can defeat a missile in some cases.

Also I'd like to say that flares aren't outdated yet. A couple of flares can be distinguished from an aircraft. But a wall of flares can not be distinguished by a seeker. So if an aircraft launches a lot of flares, and uses those flares as a wall between the aircraft and the missile, it might lose the missile easily.
Dogfights are going to get deadly in the future, its no longer the time when you could tail another aircraft for minutes before taking it down. Its only a matter of seconds these days, and most of the times, the opponent gets destroyed before entering visual range.

I believe the AIM-9X can


YouTube - AIM-9x SIDEWINDER Trial

 

[jagjitnatt]

To defeat IR seekers, can you not turn off the engines after releasing the flares and drop out of the sky?

Turn 'em back on once the missile has hit the flares.

It doesn't work. The engines are so hot already, they have a high IR signature for minutes even after engine switch off.

 

[Thomas]

To defeat IR seekers, can you not turn off the engines after releasing the flares and drop out of the sky?

Turn 'em back on once the missile has hit the flares.

I would think that would be a pretty dangerous manuver and still not practical since they are generally close in missiles. I doubt you could cool the engines down fast enough. Chogy being a pilot could say better.

 

[jagjitnatt]

I believe the AIM-9X can


YouTube - AIM-9x SIDEWINDER Trial

The video you posted shows how effective heatseeking missiles are. Exactly my point.

But in every case, the flares were being dispensed in a different direction. And missiles today are capable of distinguishing a flare from an aircraft.

I was talking about a scenario in which the missile has to pass through flares to get to the aircraft. I know it is a very rare chance, but that's the only way to evade heat seeking missiles today.

 

[Thomas]

The video you posted shows how effective heatseeking missiles are. Exactly my point.

But in every case, the flares were being dispensed in a different direction. And missiles today are capable of distinguishing a flare from an aircraft.

I was talking about a scenario in which the missile has to pass through flares to get to the aircraft. I know it is a very rare chance, but that's the only way to evade heat seeking missiles today.

Your right IR missiles are effective. But keep in mind not all IR missiles are equal. Not all countries have kept up with technology. They are still using missiles developed 15-20 years ago.

 

[gambit]

Uh gambit.. would not the newer generation IR seekers that pick up the heat at the leading edges and in some cases the complete airframe itself..ala.. Python 5...or 9x..negate the IR suppression advantage??

Yes...That is correct. However, infrared sources such as leading edges from a complex body do not provide the seeker as much 'localization' of an IR source as the engines do. Seekers are programmed to focus on a body's highest concentration of IR emissions. The body itself provides the background contrast for the engines. In the case of a frontal view, leading edge IR emissions depends on the aircraft's speed, the higher the greater, and if there are insufficient contrast between the leading edges and the aircraft's fuselage, or even against background, above a certain threshold, then there is insufficient 'localization' for the seeker.

There is a complex relationship between array dimension, the amount of IR sensors in an array, and the ratio of activated sensors versus inactive sensors. The total amount of sensors DO NOT determine array dimension. A lot people confuse the two items. It is the spacing between individual sensors that determine array dimension. Sensor technology is a major factor, of course. The more sensors we pack inside an area, the greater the ratio between activated sensors versus inactive ones we can have when we come up on an IR source, which lead us to -- fusing distance.

Fusing distance is the range between the missile and the target when the missile detonate. The closer the detonation the greater the damages to the target. Say we have 100 IR sensors in an array. In one situation, we have 50 activated sensors but there is no 'localization' of these activated ones. In another situation, we have only 30 activated sensors but they are highly concentrated in a corner of the array. We then program the flight controls to accept guidance commands to turn the missile so that these 30 activated sensors begin to 'move' across the array until this 'localization' is centered. As the missile approaches the target, we expect to have an increase of activated sensors versus inactive ones. Once this ratio crossed a certain threshold, we detonate and this is the fusing distance. We have to expect the target to maneuver. As the target maneuvers, it is possible that the amount of activated sensors can decrease or increase inside a time frame. So inside this time frame, what is the ratio between activated sensors versus inactive ones AND the rate of changes that we are willing to tolerate before we could lose the target?

So for leading edge IR detection, we do not have as localized IR sources as the engines do across the array. Not only that, they are not as strong as the engines. The activated sensors, or pixels, are spread out across the array. As the target maneuver, we will have x-y changes and rate of changes for activated pixels compared to inactive ones. What is the threshold for loss of activated pixels, and we have to expect there will be losses compared to the constancy of the engines, before we alert the pilot that we have an IR lock? Remember the fusing distance criteria.

 

[SQ8]

But then.. by increasing pixels.. is it not possible to greatly diminish the chances of a false "hit" on the recognition algo?
Say a flare or focused IR beam on the seeker?

 

[gambit]

Infrared characterization of jet engine exhaust plumes

The focus of current research is the measurement, modeling, and simulation of the spatial, temporal and spectral behavior of gaseous radiation from a jet engine exhaust plume. Infrared imaging using a scanning infrared camera has been used as a flow visualization technique.

is it possible to create a jet engine system with a cold exhaust or by-product? | Automotive Gallery, Videos, Preview, News and Store

is it possible to have a military jet, witha cold exhaust…. like a cold after burner? can u produce a form of thrust large enough to propel an aircraft at super sonic speeds with a by-product being cold… i know the jet engine is just vapopr burning, thrust creating the flame but is there another form? can u create a military jet with a very low if not no infa-red signature? if a stealth aircraft were to be fired and the missile was a heat seeking one, there would be no hope for the missile…. and if it was radar guided, and the aircraft was stealthy and manueverable, it would greatly increase the pilots chance of survival… just an idea…

In order to propel itself, an airplane needs to expend energy. And no matter how carefully done, this incurs a raise in overall entropy. To get some air to move faster than the environment creates eddies on the boundary of the jet flow, and those eddies will dissipate by raising the temperature.
Every form of energy will eventually dissipate in heat.
So, the short answer to your question is: no, unfortunately.
The laws of physics do not allow for perfectly cold energy.
What you can do is dissipate the heat over a larger volume so that the exhaust plume is bigger but colder overall (but still contains the same amount of waste heat. Stealth aircraft use that technology to reduce their infra red signature (a bigger plume that is not as bright in infra red is more easily missed than a very bright tiny one — one can easily spot a star in the night sky, but the same amount of light over a larger area is very hard to distinguish — explaining why flares can be used to distract an incoming missile).

Take note of the question and the highlighted answer. On a turbofan engine we can mix much cooler bypass air into the exhaust plume to reduce its IR emission. The operative word is 'MIX'. If inefficiently designed, the much cooler bypass air can actually insulate and stabilize the SHAPE of the hot exhaust plume, allowing for higher IR emission, longer in duration, and further in distance away from the aircraft. A circular nozzle already set the stage for this potentiality in that the circular plume has the smallest surface area -- dissipatively speaking -- compared to its volume.

Any wonder why the B-2, F-117, and F-22 has non-circular exhaust? The F-117's exhaust has the lowest IR emission, not more because its engines are non-afterburners, but more because they do not have exhaust plumes. The exhaust flow volume is spread over a much larger surface area via those narrow nozzles and cools much more quickly.

 

[gambit]

But then.. by increasing pixels.. is it not possible to greatly diminish the chances of a false "hit" on the recognition algo?
Say a flare or focused IR beam on the seeker?

Yes...That is why IR missiles have been gaining lethality as technology improves.

But the main problem is still about discrimination when the IR seeker sees multiple IR sources that are localized across its array but those IR sources are within a statistical range of intensity among themselves. The analogy is looking at a section of the night sky and sees several stars with similar brightness level. Because we know that this is a flight environment, therefore each IR source will have different behaviors, we can install a 'target adaptive guidance' (TAG) algorithm, assign to each IR source this algorithm, track their behaviors, and decide which IR source is most likely the true target. Because an IR emission cannot give us range or 'z' axis information, we have to rely on x-y changes across the array in order for the TAG algorithm to work. This combination of array technology and software sophistication increases an IR missile's lethality.

 

[Irfan Baloch]

Considering that the newer seekers are fairly resistant to being decoyed by even the more intense flares.. It is quite likely that maneuverability will soon take a backseat when it comes to the close in knife fights..
even then.. high instantaneous turn rates will matter more I suppose..
the first shot being the one that matters..
With almost all new combat aircraft armed with HMS... the idea of having to fight WVR would be dangerous for anybody.

just reminds me a comment about F-22 that it might be one of the last "manned" fighter jet.. looking at the advances of missiles. it seems that only advanced combat drones will be the answer of future air combat.
taking out the "weak link" i.e. human out of the fighter would give far more flexibility and oppertunity in design & capability to the designers considering what a present day "manned" combat plane has to face.

I know again there will be an aother stalemate when all options will be exhausted in unmanned drones untill a new technology redefines the concepts and everyone gets on the drawing board from start.

 

[Anti_Zionist]

Pakistan and India follow entierly different way of purchasing the equipment. While India plans ahead in time and thinks for years ahead. Pakistan on the other hand looks more at current threat or recent future threat like 3 to 5 years. They have been very smart as well, we bought AWACS after years of lobbying planning etc. The moment the deal was made Pakistan got something similar from SWEDEN, pretty much in the same time as India.

So I guess when they will see in coming 3 to 5 years when PAK-FA will be possible, they will then start thinking about their options and buy something off the shelf.

I guess right now they are banking on China and trust me China will give them JXX when they make it.

My friend your air chief said that IAF has 50 % of its equipment in no go condition.You call this future planning? its not future planning to buy 250-300 5G jets, future planning is to make cheap awesome ones at home(JF-17) got the point my buddy?

 

[SQ8]

Sticks and stones perhaps..?