Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Philip » 15 May 2018 19:38

Is there any prod. schedule officially given out by HAL until 2020? Will give us an idea of how many aircraft we can expect by 2025.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 15 May 2018 23:19

JayS wrote:
Cain Marko wrote:They are probably referring to the Derby extended range variant saar


I remember once Tejas FB admin confirmed that ER version is given for LCA. Can't remember if its already in work or it will follow.


I think the recent reports of Derby integration with mk1 all showed non ER version of Derby. But my guess is that since the 2052 is likely to get the mk1a contract, Derby ER is likely for that bird and this report is in that context.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby JayS » 15 May 2018 23:30

Cain Marko wrote:
JayS wrote:
I remember once Tejas FB admin confirmed that ER version is given for LCA. Can't remember if its already in work or it will follow.


I think the recent reports of Derby integration with mk1 all showed non ER version of Derby. But my guess is that since the 2052 is likely to get the mk1a contract, Derby ER is likely for that bird and this report is in that context.


Old post of mine and some discussion on the same page. LCA currently has i-Derby it seems and ER version will follow.

viewtopic.php?f=16&t=7263&p=2183142&hilit=Derby+ER#p2182809

So this "Meteor -Class" Missile is most likely Derby ER.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cybaru » 16 May 2018 00:17

JayS wrote:Karan is referring to MK1. The one you point out is for MK1A. Its one of the 4 key changes from MK1 > MK1A.



Ah ok! thanks for clarification. So I presume with the selection of EL/M 2052, we will see the paws-2 maws and El-8222wb jammer?

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby SaiK » 16 May 2018 05:31

manjgu wrote:Did i read somewhere that Meteor is too big for LCA??

You will also read the validations later (vision 2020?) when LCA Mk2 fires BrahMos NG. Now, that should be at least 150km ranged weighing 1.5 T.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby mody » 16 May 2018 13:06

Is there any plans to have IRST on the Tejas? IAFs experience using IRST with MiG-29 and Su-30 is quite positive.
So its kind of surprising that they have not asked for IRST to added to the Tejas.
The Rafael, EF-2K and most other modern fighters have an IRST.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby JTull » 16 May 2018 14:46

mody wrote:Is there any plans to have IRST on the Tejas? IAFs experience using IRST with MiG-29 and Su-30 is quite positive.
So its kind of surprising that they have not asked for IRST to added to the Tejas.
The Rafael, EF-2K and most other modern fighters have an IRST.


https://www.flightglobal.com/news/articles/india-acquires-litening-targeting-pod-426811/

The new Litening 4 pods have FLIR. India inked about $500mln deal with Israel recently for 150 of those.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 16 May 2018 15:43

JTull wrote:
mody wrote:Is there any plans to have IRST on the Tejas? IAFs experience using IRST with MiG-29 and Su-30 is quite positive.
So its kind of surprising that they have not asked for IRST to added to the Tejas.
The Rafael, EF-2K and most other modern fighters have an IRST.


https://www.flightglobal.com/news/articles/india-acquires-litening-targeting-pod-426811/

The new Litening 4 pods have FLIR. India inked about $500mln deal with Israel recently for 150 of those.

How far will fuselage mounted pods help in a2a combat considering their fov will be limited? Just wondering...

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Pratyush » 16 May 2018 16:27

Cain Marko wrote:How far will fuselage mounted pods help in a2a combat considering their fov will be limited? Just wondering...


The IAF has to answer your question. But from all indications, they are sure of this setup. And are confident of meeting their requirements.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby JTull » 16 May 2018 17:40

Cain Marko wrote:How far will fuselage mounted pods help in a2a combat considering their fov will be limited? Just wondering...


For light fighters, it may not make sense for every aircraft to carry it. Having some pods with every sqn may be enough. Pods can be upgraded and newer pods are much easier to procure/integrate. Fixed FLIR have their own advantages (bigger, more power, free space for other stores, etc) but they've to wait for MLU to be planned for entire fleet. AMCA should definitely have it.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Lalmohan » 16 May 2018 20:12

does litening even have an a-2-a mode?

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Austin » 16 May 2018 20:59

IRST does not have much utility beyond close dog fights but they would still need a radar or laser to range the target that can alert a LWR or RWR..... and one can always use the sensor IIR of modern WVR missile that is cued to helmet to see the target passively , IR sensors is also limited by weather conditions , so not having IRST is not a downside they can get compensated by AAM sensors

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby JTull » 16 May 2018 23:35

Lalmohan wrote:does litening even have an a-2-a mode?


Apparently, L-4 does.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby tsarkar » 17 May 2018 00:39

Cain Marko wrote:How far will fuselage mounted pods help in a2a combat considering their fov will be limited? Just wondering...


Ummm, do fighter planes physically shove each other for air superiority like Sumo Wrestlers shoving each other? In that case FOV will be limited.

But if they keep a separation of 500 meters to 2 km, which is also the range weapons arm to prevent damage to own aircraft from explosion, then the 500 meters distance is approx 40 times the length of the fuselage.

The Field of View Cone is far greater than any shadow from the fuselage.

So if fighter planes physically push each other like Sumo Wrestlers with zero separation, then there will be a shadow from the fuselage.

If they engage at 500 meters separation, there is no effect of shadow either in look up or look down mode.

Very basic geometry and trigonometry.

The Su-30MKI IRST has no practical look down limitations from shadow from the radome. The Litening Pod has no practical look up limitations from shadow of the fuselage.

Original IRST of F-4 & F-14 were actually under fuselage

Image

Better example
Image

Image

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby tsarkar » 17 May 2018 00:56

Lalmohan wrote:does litening even have an a-2-a mode?


https://www.flightglobal.com/news/artic ... ty-408161/
The next generation of Rafael’s Litening targeting pod will be able to operate in an air-to-air mode, helping to identify targets that have been previously detected by a fighter’s radar.


It was IAF pilots who discovered that Litening works great in A2A mode. The Israelis then did the integration with radar.

https://www.flightglobal.com/news/artic ... od-426811/
Rafael will supply 164 examples of its Litening targeting pod to the Indian air force, for use on four types of combat aircraft including New Delhi’s Sukhoi Su-30 fighters.

Guy Oren, director of Rafael's electro-optical systems unit, says the pods will be delivered in the next couple of years.

An advanced version of the Litening 4 – the Litening 4 I – will be supplied. The improved system has been equipped with upgraded infrared cameras and a charge-coupled device colour camera to help identify targets on the ground, particularly dense areas, Rafael says.


The four types are Su-30MKI, Mirage 2000, Jaguar and MiG-27UPG since Tejas hadnt entered IAF squadron service then. There were previous purchases before the 164 order.

https://www.livefistdefence.com/2010/07 ... ig-27.html

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 17 May 2018 03:56

tsarkar wrote:
Cain Marko wrote:How far will fuselage mounted pods help in a2a combat considering their fov will be limited? Just wondering...


Ummm, do fighter planes physically shove each other for air superiority like Sumo Wrestlers shoving each other? In that case FOV will be limited.


The Field of View Cone is far greater than any shadow from the fuselage.

So if fighter planes physically push each other like Sumo Wrestlers with zero separation, then there will be a shadow from the fuselage.

If they engage at 500 meters separation, there is no effect of shadow either in look up or look down mode.

Very basic geometry and trigonometry.

The Su-30MKI IRST has no practical look down limitations from shadow from the radome.
]


Tsarkarji I'm not sure about your sumo wrestler analogy but could do without the patronizing please. Are you actually saying that the su 30 ols can scan down just as well as it can scan up? If so, I'd be rather surprised considering the manufacturer data itself shows scan angle limitations in the downward direction.

The ols 35 which is the newest design on the mig 35 and much newer than the ols 30 on the mki has a fov of -15 in look down but +90 in look up i.e. these are the scan limits for it. If fov was not limited, it would be 90 deg in both directions in elevation/declination

IOWs, sticking the irst on the top of the nose is useful against aerial targets but not so good against ground targets. in a ground attack role, the fuselage mounted litening should do great, but in a2a, it will certainly suffer for elevation scan limitations.
Fwiw, This was confirmed in an IHS James report on irsts, especially the PIRATE on the tiffy

It is for this reason that the mig 35 carried an irst in the traditional a2a spot as well as a ventrally located spot under the fuselage on the starboard side aka ols k.

So I'm still not sure how a ventrally located irst can do the same job as a nose cone irst against high flying targets.

Afaik, while the litening can be used in a2a mode, it's primary focus remains a2g unlike the ols on a flanker or fulcrum.

Another thing to note... Almost all fighters that were designed to use irst from the scratch as an a2a sensor had these inbuilt on top of the nose. Egs include ef2k, Rafale, gripen and of course the Russian designs. The rest which use irst as an afterthought, e.g hornet or eagle and in the examples shown in your pictures have them fuselage mounted.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 17 May 2018 04:46

Austin wrote:IRST does not have much utility beyond close dog fights but they would still need a radar or laser to range the target that can alert a LWR or RWR..... and one can always use the sensor IIR of modern WVR missile that is cued to helmet to see the target passively , IR sensors is also limited by weather conditions , so not having IRST is not a downside they can get compensated by AAM sensors


For engaging targets, yes. Getting targeting coordinates is not easy without lrf, which had range limitations, however detection and therefore situational awareness can happen at much longer ranges IIRC.

The French are pretty hush hush hush on this topic and their fabled osf mica iir combo. Supposedly can detect aerial targets at 150km, and engage at BVR distances although not so far I think.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby shiv » 17 May 2018 07:15

IRST is a tool. Mounted on top it will see forward and up. Mounted underwing it will see forward and down. Every a/c does not need to be IRST equipped - but the one that has IRST in an underwing/underfuselage pod can serve as an IR early warning system by flying separately at high altitude away from the main attacking group (in look down mode) covering a cone of airspace. Google gives 20 km detection for humans - I would expect at least 100 km for hot aircraft skins and exhausts. How much cone is needed and what coverage is possible depends on the exact specs that we don't know. Mostly Gookal says that wide angle can detect and then signal can be focused and examined like telephoto lens.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby sanjaykumar » 17 May 2018 09:06

The software algorithms for A2A are apparently much simpler than A2G. For reasons that are perhaps obvious.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Prasad » 17 May 2018 11:03

Hence the '5th gen' need to have IR sensors all over the aircraft, DAS in the F-35, to have 360 degree view.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby JayS » 17 May 2018 11:19

Image

Look where the pod is positioned. It should have no hindrance looking up at least on one side. more than half the front hemisphere is unobstructed. The left side would be a bit shadowed due to fuselage but not completely. I suppose 60deg positive elevation range itself would be more than sufficient. And you can always orient the attitude of the aircraft for better view.

To me underslung FLIR would cover almost entire practically useful envelop either directly or with a bit re-orientation of the jet (anyhow the fighter would be flying directly towards the target most of the times). Its not the best but definitely good enough. I am sure they have quite a wide angle lenses to further help them.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby mody » 17 May 2018 16:21

Many aircrafts like the Su-30MKI, have both. A nose mounted IRST, primarily for to A2A role and a Litening POD for A2G role.
Perhaps with the new Litening 4, the A2A mode is good enough to not require a separate IRST pod.

Having a dedicated nose mounted IRST for A2A role would offer a slight advantage, but perhaps not enough to justify adding one, apart from having the Litening 4 or Litening 4-I.

Will have to wait for IAF to say otherwise.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Lalmohan » 17 May 2018 17:42

I doubt there is enough space or power available to drive an inbuilt IRST on the Tejas
(I am assuming that Litening has some form of ram air generator)

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby tsarkar » 17 May 2018 18:28

Cain Marko wrote:
tsarkar wrote:Ummm, do fighter planes physically shove each other for air superiority like Sumo Wrestlers shoving each other? In that case FOV will be limited....If they engage at 500 meters separation, there is no effect of shadow either in look up or look down mode.
Tsarkarji I'm not sure about your sumo wrestler analogy but could do without the patronizing please.

Cain Markoji, my apologies, no offence intended but the sumo wrestler analogy was a valid datapoint.

But here are more relevant datapoints
https://en.wikipedia.org/wiki/AIM-9_Sidewinder
The warhead features a safe/arm device requiring five seconds at 20 g (~200 m/s²) acceleration before the fuze is armed, giving a minimum range of approximately 2.5 kilometers.


http://www.designation-systems.net/dusrm/m-120.html
minimum range is said to be 2 km


There is a reason for these minimum ranges. The aircraft too is flying forward with a high relative velocity and the missile needs to clear the launch aircraft to prevent its warhead explosion damaging launch aircraft or causing FOD ingestion in the engines.

Now every poster (other than Shiv) is thinking in terms of aircraft geometry. Only Shiv wrote in terms of engagement geometry and "cone of aerospace."

If in the two Tejas photos posted, one by JayS & other by me, and the F-15 photo, one draws a simple cone with EO Ball as the vertex and a line segment from the vertex passing through the farthest extremity of the aircraft (pitot tube in case of Tejas and radome tip in case of F-15) with a slant height of 2 - 2.5 km, one gets a cone of aerospace of great volume and base area. The blind spot will be a small percentage of the cone base area. As the slant height increases beyond 2 km to 5 km, the base area of the cone proportionately increases while the percentage of blind spot in the cone base area reduces even further.

The probability of an enemy aircraft 5 km away to penetrate a blind spot in the overall base area is very remote.

A graphical tool would explain this much better by drawing cones of successively longer slant heights.

Cain Marko wrote:So I'm still not sure how a ventrally located irst can do the same job as a nose cone irst against high flying targets.

The Litening sensor head swivels in elevation and azimuth as does the COMPASS head. In this photo it is swiveled completely back to prevent FOD damage to sensor head during takeoff & landing.
Image

If the high flying target is 2 km or 5 km away, then the elevation angle will be within the elevation angle of the sensor head and seeker FOV.

If the high flying target is within 2 km, then you cant use missiles and gun is the only remaining option with gunsight.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby tsarkar » 17 May 2018 19:25

Typical missile kill ranges from a Pakistani site of all places http://www.pafwallpapers.com/kill_illustrations.htm
The Pakistanis have done a very factual job in describing maneuvers and presenting air data.
At 3.4 miles from the target, while flying at an altitude of 21,500 ft on a heading 0f 280 degrees, Badar fires his first missile.

He continues to close and lets go a second missile at 2.9 miles on the same heading but now at 23,000 ft.

firing his starboard AIM-9L at a range of 2.5 nm

He duly launched an AIM-9L from a range of 2.7 nm in a head-on pass.

nm = nautical mile

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby titash » 17 May 2018 19:58

JayS wrote:Image

Look where the pod is positioned. It should have no hindrance looking up at least on one side. more than half the front hemisphere is unobstructed. The left side would be a bit shadowed due to fuselage but not completely. I suppose 60deg positive elevation range itself would be more than sufficient. And you can always orient the attitude of the aircraft for better view.

To me underslung FLIR would cover almost entire practically useful envelop either directly or with a bit re-orientation of the jet (anyhow the fighter would be flying directly towards the target most of the times). Its not the best but definitely good enough. I am sure they have quite a wide angle lenses to further help them.


One more thing to note. Most likely PAF/PLAAF "intruders" are going to come in at low level to avoid high power ground based radar and SAMs. If a pair of Tejas are flying CAP missions, then the targets are likely to be in the "below" hemisphere. Well suited for the Lightening pod to pick them up unobstructed.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby ramana » 17 May 2018 20:53

Prasad wrote:Hence the '5th gen' need to have IR sensors all over the aircraft, DAS in the F-35, to have 360 degree view.


Like curse of Indra!!!

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby ramana » 17 May 2018 20:58

Guys why this periodic going off on tangent in Tejas thread?
And compare to USAF which faces many threats while IAF has tow main ones; PAF and PLAAF.

Also those asking questions should occasionally thank those providing answers and imbibe some know how on how to look for data.

tasrkar and JayS thanks for the data.

Folks got hot about the sumo wrestler analogy but close in dogfights with gun are sumo wrestler type of close in maneuvers.

Look at the gun range.
And for WVR if in close in combat the analogy is apt.
Nothing disparaging.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 01:51

Thank you Tsarkarji for the viewpoints. I'm still not sure how the irst, irrespective of it's ability to swivel, can see past the airframe/radome which obstructs/confuses signals ffrom one entire quarter of it's top view. This becomes all the more prominent in case the engagement is at closer distances or against clutter. Yes, it will do but not ideal imvho. Perhaps it's mitigated even more because of how the pod is placed so far forward on the Tejas, but still there is a penalty. Again, look at all designs where irst is embedded from get go, it is always on the top of the nose. Even the gripen e and f16 BLK 60 which entail airframe modifications to the original, included the ball on the dorsal side for a2a role.

My takeaway regarding the irst placement is that litening will serve the purpose well enough in present circumstances. Mk2 may or may not see ideal placement of irst ball at base of cockpit but I sure hope it does. Ultimately the strength of irst is detection at high altitude against an open sky where the temperature contrasts really stand out, it doesn't help to reduce this strength by limiting/obstructing the view.

JayS wrote:Image

Look where the pod is positioned. It should have no hindrance looking up at least on one side. more than half the front hemisphere is unobstructed. The left side would be a bit shadowed due to fuselage but not completely. I suppose 60deg positive elevation range itself would be more than sufficient. And you can always orient the attitude of the aircraft for better view.

To me underslung FLIR would cover almost entire practically useful envelop either directly or with a bit re-orientation of the jet (anyhow the fighter would be flying directly towards the target most of the times). Its not the best but definitely good enough. I am sure they have quite a wide angle lenses to further help them.


Yes, this solution should work for the most part but certain areas will definitely be in a blind spot. You have to reorient the jet to a great angle to really capture that spot, which seems like an entire quadrant. This blind spot cannot go away unless you put an irst on the nose at the base of the canopy as in Rafale or typhoon r gripen. This is what I'd like to see for the mk2 as well

For coverage below, the podded version should be more than sufficient since there is no restriction from the airframe.
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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 01:59

titash wrote:One more thing to note. Most likely PAF/PLAAF "intruders" are going to come in at low level to avoid high power ground based radar and SAMs. If a pair of Tejas are flying CAP missions, then the targets are likely to be in the "below" hemisphere. Well suited for the Lightening pod to pick them up unobstructed.

Not necessarily. Not if they are going to use stealthy designs in the future. Also detection against ground will never be as good as detection against clear high altitude skies, which is where stealthy designs are wont to operate.

thing to note about irst is that it's purpose is not anymore relegated to merely engaging at wvr, detection and identification is possible at very long ranges, and this takes on a lot of importance against stealth targets, which tend to evade radar but are susceptible against irst thanks to their penchant to fly super high. This is one reason why the eurocanards all went with the irst ball to begin with. Increased SA at high altitudes.
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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 02:27

Typing out relevant excerpt from Airborne IRST Prepares to Leap into Uncharted Territory - IHS Feature Report, 2009 (ihs.com):

The PIRATE sensor head is mounted above the Typhoon's radome (the optimum position for IRST air to air operation) and slightly to the left of the airfcarft centerline (allowing for limited look down in FLIR mode). As a result, a2g applications (particularly at low level) will be inevitably compromised . It is understood that much work has been undertaken to minimise interference with look down modes due to energy absorption by and re-radiation from the radome.

IOWs, for a2a ops, optimal positioning is on top of the nose and radome interference via signature absorption and generation will cause problems if the irst is placed below (for a2a) or above (for a2g) the radome. There is no getting around this. Hence the 360 degree DAS on F35 or the OLS UEM and K combo on the MiG35 I guess.

Further, IRST is not simply for WVR engagements:
Pirate automaticall detects the IR signature of the aircraft at long ranges (beyond visual range - in excess of 50 km), over the entire FoR.....As a totally passive sensor, it enables the aircraft to gather early intelligence of threats and to maneuver into a tactically advantageous position without being detected by ECM, assisting the stealthiness of an interception and enhancing situational awareness


More pertinent for India and the Rafale:
While declining to be specific on the details of the sensors on the OSF, Brousse confirmed to Jane's that "the dual channel IR/CCD TV, linked with the LRF allows 3D targeting coordinates to be fed into the system thus making silent visual id possible, (which I assume is at WVR ranges since LRFs always tend to have small ranges). Other sources have suggested that the IR element in OSF has a max operational range of 150km

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby ramana » 18 May 2018 03:09

Cain Marko, Very good information.
My take away is for A2A the IRST should be above centerline and for a2g it should below centerline.

And a good IRST acts as a passive sensor up to 50km.

So for multipurpose aircraft, a podded sensor looking ahead should do the same job, if it has a wide field of view?
Yes its a compromise but helps avoid single purpose aircraft.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 04:27

ramana wrote:Cain Marko, Very good information.
My take away is for A2A the IRST should be above centerline and for a2g it should below centerline.

And a good IRST acts as a passive sensor up to 50km.

So for multipurpose aircraft, a podded sensor looking ahead should do the same job, if it has a wide field of view?
Yes its a compromise but helps avoid single purpose aircraft.

You pretty much capture it Ramana sir, however the detection ranges can be well in excess of 50km, note the osf claim. Podded sensor imvho is doable as an afterthought solution and will work I'm sure with lca. However, I'd like to see a nose solution for future mk2, 3 etc..

Another issue with the pod being the drag associated with external pods, which may be a factor in air combat.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby shiv » 18 May 2018 06:37

Cain Marko wrote:Typing out relevant excerpt from Airborne IRST Prepares to Leap into Uncharted Territory - IHS Feature Report, 2009 (ihs.com):

The PIRATE sensor head is mounted above the Typhoon's radome (the optimum position for IRST air to air operation) and slightly to the left of the airfcarft centerline (allowing for limited look down in FLIR mode). As a result, a2g applications (particularly at low level) will be inevitably compromised . It is understood that much work has been undertaken to minimise interference with look down modes due to energy absorption by and re-radiation from the radome.


A podded IRST on a wing pylon has many advantages because of the above constraints. The above is for a2a onlee. A podded IRST can look forward and down from 5000 feet or 40000 feet. At 40,000 feet the horizon is 400 km away. Anything above the horizon can theoretically be seen as long as it comes within range of the detector. With the latter a whole volume of airspace is covered including low flying intruders at a distance as they come up over the curvature of the earth. The IRST carrying aircraft need not be embedded with other attacking aircraft but can simply be flying high and alone, separately while staying in comm using secure comm. And any aircraft with the capability can carry it because it is on a pylon.

While there is no guarantee that hostile aircraft will fly in the cone - the cone can be pointed at "areas of interest". Conversely there is no guarantee that even a stealthy hostile aircraft will approach the IRST cone nose first. The hostile aircraft may be turning away or showing a side profile where the exhaust plume is seen better

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby srin » 18 May 2018 06:49

I don't know about the podded IRST (LItening et al) but IIRC the OLS that MIgs and Sukhois have is integrated with the pilot's helmet, so that the IRST swivels based on where the pilot is looking. There was one Youtube video I saw long ago but not able to find it right now.

I've also just not seen the Litening pod for A2A (maybe because it takes up one more hardpoint ?), so while the pod may have some A2A uses, my belief has been that OLS is pretty adequate for A2A.

Though coming back to where we started, I don't know why the Tejas doesn't have a nose-mounted OLS.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 08:23

Yes, this whole "silent" theme has been the Rafales USP from the beginning...the rumors of active cancellation and passive detection via Spectra, the claims about OSF, the relative negligence of radar (size) and the utilization and development of a bvr IIR missile all add up to something interesting. May be that is why the IAF is so hot for Katrina and then again, maybe it is all hot hawa

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby fanne » 18 May 2018 08:46

Didn't we read that LCA is too crammed and small for a IRST?

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby shaun » 18 May 2018 09:07

now replace "mysore sandal bars" with the above !! :wink:

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Prasad » 18 May 2018 10:41

IRST isn't just the ball but a big box below it that needs space in the nose. LCA is rather tight on space.

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Re: Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Postby Cain Marko » 18 May 2018 11:19

If Gripen can manage it, why not lca mk2?


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