LCA Tejas: News and Discussions

rahulm · Post by **rahulm** » 26 Aug 2016 19:45

Part 4

MK2: THe MK2 is driven by the IN. The design is complete and with end user for sign off. End user is concerned, perhaps rightfully, that sign off might lead to loss of focus and top talent from MK1 tests. MK2 sign off has, therefore, been stage gated to achievement of certain Mk1 test points. One can argue wether this is the right approach but this is where it stands today.

Three will likely be no 2 seater version of MK2. This would speed up development timelines. The thinking is MK1 2 seater version with current engine has enough to train pilots to graduate to MK2.

There is also a feeling that once MK2 comes close to the finish line, IAF will jump on the wagon.

Range is one of the issues with desi radome. There are others.

Karan M · Post by **Karan M** » 26 Aug 2016 19:49

Great details Rahul M - yes, best ADA first deliver on Mk1 then move to Mk2. Thanks for posting these very interesting snippets!

IIRC we used MiG-23 two seaters to even train MiG-27 pilots. So in a way, precedent exists to 'manage' with single seaters of one type alone..

I hope IAF commits to Mk2 sooner than later. Their airframe shortage is not going away soon (IMHO) and more Tejas the better..

Cybaru · Post by **Cybaru** » 26 Aug 2016 23:57

Rahul,

What kind of increase is planned on the range/fuel front? Did you address that issue already?

Thanks.

Indranil · Post by **Indranil** » 27 Aug 2016 02:17

^^^ As you can imagine, those numbers should not and will not be discussed on this forum. All we need to know is that LCA has a world class radar, peering through a world-class radome, hence the range is also world-class. Indigenous manufacture capability is not there yet.

Karan, welcome back. I don't know much about this topic, but you kind of started answering some of the questions that had sprung up in my mind naturally. So, please continue to elaborate. We are making a lot of radomes big and small: Jaguar IM, big belly bulges on the Dorniers, the big one on top of our AEWACs, and smaller ones in front of our missiles. I would love to know what makes you think that we have world class material and manufacturing technology in India. I am having problems in understanding the following:
1. First of all project management: If the shortfall in the desi radome is this big, ADA must have known this from ground testing itself. What the hell was ADA doing about this critical requirement till post IOC!!!
2. Second, if this know-how exist within India, but with a different lab/production agency, why was this contingency not exercised, say as soon as this shortfall recognized?
3. For me it is much easier to believe that we don't have the capability to built large ceramic radomes for fighters anywhere in India. For the other use-cases, we are either making do with what we have (e.g. in Jaguar IM/IS, where we don't need a 80+ km range, or on missiles where the seeker is only for terminal guidance), or we have the technology for manufacturing the same for smaller radomes (again Jaguar IM/IS's and missile noses) or we can manufacture them large enough, but only in specific shapes (Dorniers/AEWACs). AFAIK, the Harrier radomes were imported as well.

Sid · Post by **Sid** » 27 Aug 2016 02:36

Maybe the current radome was not designed to be compatible with Israeli radar and hence the shortfall.

When they started all they had was MMR but for some reason never went back to fine tune it for Elta model.

SaiK · Post by **SaiK** » 27 Aug 2016 03:24

The additional 7kVA (max config) for 2052 need more power.

Indranil · Post by **Indranil** » 27 Aug 2016 03:33

Sid wrote:Maybe the current radome was not designed to be compatible with Israeli radar and hence the shortfall.

What does this mean?

Karan M · Post by **Karan M** » 27 Aug 2016 04:27

indranilroy wrote:^^^ As you can imagine, those numbers should not and will not be discussed on this forum. All we need to know is that LCA has a world class radar, peering through a world-class radome, hence the range is also world-class. Indigenous manufacture capability is not there yet.

Karan, welcome back. I don't know much about this topic, but you kind of started answering some of the questions that had sprung up in my mind naturally. So, please continue to elaborate. We are making a lot of radomes big and small: Jaguar IM, big belly bulges on the Dorniers, the big one on top of our AEWACs, and smaller ones in front of our missiles. I would love to know what makes you think that we have world class material and manufacturing technology in India. I am having problems in understanding the following:
1. First of all project management: If the shortfall in the desi radome is this big, ADA must have known this from ground testing itself. What the hell was ADA doing about this critical requirement till post IOC!!!
2. Second, if this know-how exist within India, but with a different lab/production agency, why was this contingency not exercised, say as soon as this shortfall recognized?
3. For me it is much easier to believe that we don't have the capability to built large ceramic radomes for fighters anywhere in India. For the other use-cases, we are either making do with what we have (e.g. in Jaguar IM/IS, where we don't need a 80+ km range, or on missiles where the seeker is only for terminal guidance), or we have the technology for manufacturing the same for smaller radomes (again Jaguar IM/IS's and missile noses) or we can manufacture them large enough, but only in specific shapes (Dorniers/AEWACs). AFAIK, the Harrier radomes were imported as well.

Thanks Indranil for the welcome back - thanks to all you guys & Seetal for getting this up and running.

TBH, the impression I get of ADA - from whatever interactions, information i gathered over the years is that they are attempting to ride three horses - indigenization, user requirements (which means looking at imports when overambitious local programs don't work out) and CAG/GOI rule book shouldn;t be broken.
Rahulm would have the real details here so at best I can only guess.

In the case of a more well funded and laissez faire establishemnt, such things would go in parallel. Each time ADA has done something like that, they have been rapped on the wrist. Why buy X when Y was there. A few years back CAG rapped HAL/ADA for purchasing some unit which was already in development at NAL and which progressed.

This is a country where the beacounters even rapped a Navy chief for the Barak import when the developer itself openly gave the Navy a clean chit to buy the alternative since the Trishul would not be ready in time (and we are yet to demonstrate an integrated system which crosses that hurdle, though Akash has cleared multi-path reflection issues with over the sea firing & Revathi has been deployed in the naval role).

So what happens is they wait till incontrovertible proof comes via testing etc that the "domestic option" didn't work out & then things get proceeded with.

This kind of goes with 1 & 2 both - the long process to choose a MMR partner (despite sanctions etc), the convoluted process for engines (even when the Kaveri risk was evident), the lack of funding for the primary propulsion (which means the "blue-sky" approaches to work with anyone else despite sanctions, namely the Russians wouldn't even be on the plan).

Coming to the technical capabilities - I don't think we have the ability to make a Cobham equivalent system right off the bat - airborne FCRs & assorted subsystems are still work in progress for us. Cobham itself took time as well. However as you'd know, NAL now has CEM to work on such programs for the long term. http://www.nal.res.in/pdf/Computational ... ratory.pdf
FSS work is clearly directed at AMCA and other programs. http://www.nal.res.in/pages/cemlab/CV-2 ... arayan.pdf

So in short, ADA would have seen it is not fixable right off the bat, and would look outside for quicker answers.

However, given time (and effort) it can be done. But ADA seems to have got clearance (with HAL) for a MK1A with an imported AESA & SPJ, we have clearance for an Israeli weapons fit for Mk1 - hence the IAFs requirement of a timeline issue has allowed them to speed up things and exercise the import option. IMHO if 60-70% of the overall platform (by design) is still sourced from within India, we can live with a few imported radomes, until and unless wear and tear makes them liable for several replacements over the lifetime, in which case we should have a domestic program up and running at NAL for the long term.

IMHO radome design will proceed hand in hand with FCR work - LRDE now has an invaluable testbed in the AEW&C for airborne systems (CABS will be retaining one of the original 3 ordered by the IAF if that plan still holds).

Some 6 years back, we had to run to the Israelis for nearly the entire back-end of the radar (in part because they clearly indicated mixing and matching Indian eqpt some of which worked) with their stuff was pointless and too time consuming. But today, we have an AEW&C flying with our own primary radar & Uttam even has Indian designed Tx/Rx modules. From the DRDO AR posted previously (thx to ASharma! for linking it), there are now (per my own WAG/estimate), some 11 tactical/services oriented AESA programs running in parallel at DRDO (not the BMD ones), and Uttam is the 12th. So in a methodical fashion we have managed to systematically go after most of the import segments.. IMHO radomes are also next on the list. As will be datalinks and SDRs - currently, till the CAIR program comes good, I suspect even those are basically built around Israeli units.

malushahi · Post by **malushahi** » 27 Aug 2016 04:54

Karan M wrote:I don't think we have the ability to make a Cobham equivalent system right off the bat - airborne FCRs & assorted subsystems are still work in progress for us.

would that be a material issue or a fabrication issue?

Dileep · Post by **Dileep** » 27 Aug 2016 07:32

The person I talk to is not an RF expert. He tells me that it is essentially a fabrication issue. See, there are a number of different bands the radar uses, which all must see the same propagation characteristics. An additional requirement is, the propagation must be the same in all directions.

As Indranil mentioned, I heard the actual range figure and how it was arrived at, but can't tell. But think this way.. How do you test the range? assume the spec is, like 350 yojanas against a target of RCS of 12 kol squared. Are you going to create a sphere of radius 2 kol as the target? No.. It is impossible to validate this spec. So, the arrangement is to actually fly the tiniest and sneakiest platform we can get, and see how far it can be seen during the different maneuvers.

The only thing we can safely say is that the system well exceeded the ASR spec, and IAF would be a happy camper.

rahulm · Post by **rahulm** » 27 Aug 2016 07:38

If there are any public domain pics of the desi radome internals we can have a true BRF style dissection

I repeat, range is important but there are other parameters which need to be satisfactory even if you have the range.

malushahi · Post by **malushahi** » 27 Aug 2016 08:43

Dileep wrote:there are a number of different bands the radar uses, which all must see the same propagation characteristics. An additional requirement is, the propagation must be the same in all directions.
...

So, the arrangement is to actually fly the tiniest and sneakiest platform we can get, and see how far it can be seen during the different maneuvers.

rahulm wrote:range is important but there are other parameters which need to be satisfactory even if you have the range.

this is what makes BR BR. may your tribe increase.

Sid · Post by **Sid** » 27 Aug 2016 08:52

indranilroy wrote:
Sid wrote:Maybe the current radome was not designed to be compatible with Israeli radar and hence the shortfall.
What does this mean?

Most of the military grade radar radomes use sandwich construction. Thickness and type of the core material used in such construction vary based on wavelength of radar frequency, and according to size and airspeed for structural strength.

Earlier construction must have been fine tuned for MMR operating frequencies. Or maybe we over designed to strengthen the radome.

Following radome selector guide gives a brief overview on radome types and their pros/cons.

http://www2.l-3com.com/essco/resources/ ... _guide.htm

Kakkaji · Post by **Kakkaji** » 27 Aug 2016 09:17

Welcome back Karan! The threads will now move faster

I am going to go off on a tangent here:

After reading Ajai Shukla’s story about SAAB offering to co-develop and manufacture the LCA Mk2, here are my thoughts:

If the GOI wants to rope in a foreign partner to speed up the development and production of the LCA Mk2, then the ideal partner in my opinion is - Dassault! My reasons are:

1. Dassault, unlike SAAB, does not have a competing product in the single-engine, lightweight category. So it does not gain by killing the LCA in the guise of co-development.

2. The LCA’s design philosophy is closer to the Mirage-2000 than the Mig-21. Dassault, with its M2K experience, can help in areas like weight optimization, reduction of test points etc, thus speeding up development. Unlike SAAB, Dassault also has experience in building naval fighters. If LCA can quickly become a true M2K++, I am sure it will make the IAF very happy.

If critical design consultancy from Dassault can be obtained under the offsets from the Rafale deal, then the huge expense on the Rafale will be justified IMHO. Otherwise, the Rafale is an avoidable luxury for India.

What do the Gurus think?

SaiK · Post by **SaiK** » 27 Aug 2016 09:49

Sure, but we have a big overhead of catch up with Rafales, JSFs and raptoriskis of the world. Given the right team and fund, it is not impossible, but we lost a lot of time from Marut to actually late 80s/90s. We have to think about production engineering efforts for LCA, maximize and optimize at economies of scale. make profit to fund further ventures into AMCA.

Rafale, PAKFA and JSF will swindle us leaving a strong back to scratch

Cybaru · Post by **Cybaru** » 27 Aug 2016 10:21

indranilroy wrote:^^^ As you can imagine, those numbers should not and will not be discussed on this forum. All we need to know is that LCA has a world class radar, peering through a world-class radome, hence the range is also world-class. Indigenous manufacture capability is not there yet.

Oh, totally understand. I am not asking for radar range (I am not particularly interested in it at all, whatever it is, its fine for first attempt). I am curious as to if there was any conversation on how much additional fuel MK2 will carry? That will also decide if MK2 has a chance to become a medium range fighter. What does the navy think about its current range and by how much would that be extended. Sorry for the misunderstanding.

Cybaru · Post by **Cybaru** » 27 Aug 2016 10:29

Kakkaji wrote: 1. Dassault, unlike SAAB, does not have a competing product in the single-engine, lightweight category. So it does not gain by killing the LCA in the guise of co-development.
What do the Gurus think?

I agree with your other thoughts, but I think any new fighter even a substitute of different category can quite easily cannibalize sales of the rafale especially if the world economy becomes tight and the buyer doesn't have unlimited funds and would prefer decent number of airframes. We have seen Gripen compete with Rafale in the same tender both here in India and abroad, and has won in Switzerland and Brazil against the Rafale.

Indranil · Post by **Indranil** » 27 Aug 2016 11:35

rahulm wrote:If there are any public domain pics of the desi radome internals we can have a true BRF style dissection

I repeat, range is important but there are other parameters which need to be satisfactory even if you have the range.

We have this.

rahulm · Post by **rahulm** » 27 Aug 2016 18:36

@indranil. I went through the entire doc. Regrettably, not enough. Thanks for posting the doc. It was a good read.

SaiK · Post by **SaiK** » 27 Aug 2016 22:59

Dileep ji, does the shape of the transmitter matter?

sankum · Post by **sankum** » 27 Aug 2016 23:48

From Tejas Facebook page

Akshay Tapte Sir, Could you please throw some light on the radar for Mk-1A ? Will it be LRDE's Uttam AESA or Elta's EL/M-2052? Thanks.

Like · Reply · 1 · 24 August at 09:59 · Edited

Tejas - LCA Uttam.. The talk of integrating Elta is on if Uttam does not show up in time

JayS · Post by **JayS** » 28 Aug 2016 01:58

From FB page:

- NP5 is in equipement stage.

- The recent rain incidence in Bhopal, was because the rain clearance workwas done on another prototype. So the precution was taken to cover it in rain.

malushahi · Post by **malushahi** » 28 Aug 2016 05:37

so what would have happened if this plane encountered a rainstorm in flight? a real possibility given that the monsoon is still on.

what am i missing here?

nirav · Post by **nirav** » 28 Aug 2016 05:48

If a specific a/c is not cleared for rain, and encounters rain in flight, mostly it would RTB or land at the nearest airfield..
Like they said, it's 'precautionary' in nature.

Kakkaji · Post by **Kakkaji** » 28 Aug 2016 07:18

Any news on the SP3? August is nearly over.

rahulm · Post by **rahulm** » 28 Aug 2016 07:43

SP3 was imminent 2 weeks ago.

Nothing on fuel and range extensions. yet. Maybe, next time.

NP2 uses second seat for gear and the entire aircraft is unbelievably crammed. There is no real estate left that can be used.it will probably never fly with a second pilot.

Indranil · Post by **Indranil** » 28 Aug 2016 11:33

This is what I could find out about the desi LCA radome.

Lightning Protection for LCA

The nose cone radome houses the radar antenna. The antenna inside the dielectricLightning strike test on LCA model radome is a major electric field stress raiser at the front of the aircraft and will always be a potential lightning attachment point. Unless suitable protection scheme is in place, the lightning strike will puncture the radome wall and attach to the radar antenna,with the risk of severe damage to the radar antenna equipment as well as the radome. The protection scheme for the radome to protect it against the direct effects of lightning has been evolved through design studies and detailed experimentation. An optimum scheme has been worked out considering both radar performance and lightning protection .

The radome with the evolved scheme has successfully withstood high voltage and high current tests carried out as a part of qualification testing.

The high voltage tests proved the adequacy of protection scheme in preventing attachment to the radar antenna structure inside by puncturing the radome.

The high current tests carried out have verified the adequacy and efficiency of the scheme while ensuring the structural integrity of the radome.

Random developments

Technology Achievements

1. Composite Pitot Adapter Development for better EM performance
2. Qualified Composite Pitot Adapter with Lightning Test on Full Scale Radome
3. Standardized Painting Scheme for Blister Free Surface
4. Established the process for achieving �15� Angular tolerance requirement on Pitot Adapter Holes

Project Milestones/Achievements

1. Delivery of Radome Assembly with due Airworthiness Certification for PV1 Aircraft
2. 4 VTR Mouldings for PV4, PV5 & 2 Flight Standby completed
3. Coupon level Mech., EM & Environmental Tests for QTAT completed which will be followed by Full Scale Radome Level Tests

And obviously the picture of Hack by Harry.

rahulm · Post by **rahulm** » 28 Aug 2016 13:06

Harry's pics provides the slightest ledge that can, perhaps, be used. Some of the points below might be silly but just go along with me.

1. What are those 2 black pipe like things?
2. What role might they play?

Maybe these 2 points are enough for now and hopefully start a discussion

JayS · Post by **JayS** » 28 Aug 2016 17:16

>> Air probe connections??
>> Lightening Protection system connection??

Sid · Post by **Sid** » 28 Aug 2016 20:11

Although following image is from MK II model, it may be an indicator to current radome design. There seems to be a support rail which goes horizontally across the radome, end to end. But looking at more TFTA radomes from Europeans, they are void of any kind of structures inside it.

This rail can be there for either structural strength or run the ground cable from pitot tube to provide earthing. It might have interfered with radar as well.
https://s13.postimg.org/ra6k11ik7/LCA_Radar_Radome.png

Karan M · Post by **Karan M** » 28 Aug 2016 22:58

Most manufacturers of the highest power radar systems have dropped nose mounted pitot tubes as it interferes with the radar performance.

Raman · Post by **Raman** » 30 Aug 2016 04:07

Those black cables are most likely diverter strips for static discharge. Radomes can build up a lot of static charge.

SaiK · Post by **SaiK** » 30 Aug 2016 09:40

The latch point contact should be enough to discharge to the main fuselage. no? why the cables?

JayS · Post by **JayS** » 30 Aug 2016 12:09

See this patent??

https://docs.google.com/viewer?url=pate ... 428270.pdf

Similar to those two strips seen in above MK2 pic. Lightening conductors. And there has to be at least one connector from pitot tube to the cockpit. I saw one schematic showing such arrangement, can't find link now. Two connection needed if they are measuring both static and total pressure. However both connection could have been combined in one of those black lines. So minimum one is needed for this purpose.

sivab · Post by **sivab** » 31 Aug 2016 21:18

https://www.facebook.com/notes/livefist ... 5075400822

India’s 5th Generation Advanced Medium Combat Aircraft (AMCA) is progressing well now in its second phase of development with several parts of the aircraft and configuration locked.
Just chanced upon this new image from the AMCA’s stealth structures workshop at the National Aerospace Laboratory, providing an updated view of the engineering going into the serpentine intakes of the concept jet.

The above image follows the series of photographs and technical illustrations accessed by Livefist over the years, depicting the engineering approach to the AMCA’s low-observability surfaces. Some of the previous ones:

And finally, chanced upon this -- a full AMCA mission scenario simulator is up and running at the Aeronautical Development Agency in Bengaluru. Here it is:

JayS · Post by **JayS** » 31 Aug 2016 22:53

^^Awesome. I know that AMCA work in ADA is going on in full swing. But didn't expect this much - simulator and all.

Bheeshma · Post by **Bheeshma** » 31 Aug 2016 23:03

The choke point is still the engine. Without an indigenous engine it is still on path like Tejas.

Philip · Post by **Philip** » 01 Sep 2016 13:59

With the engines so closely spaced,what room is there for internal weapons? Ultimately it is the type and capability of the weapons carried that matters.Weapons carried underwing defeat stealth. I am sceptical of a medium sized aircraft which will have less internal weapons space than a larger "heavy" aircraft. Will the AMCA be able to carry the planned BMos-M internally and still have room for AAMs? There was a post in one of the tds reg. the JSF combat arrival and a candid assessment by an Ru expert along with Chinese and Ru similar development. Part related to the development of the SU-27 and MIG-29.The hope was that the MIG-29 could deliver most of the capabilities of the heavier aircraft at lower cost and increase numbers.When the two aircraft were first revealed in the West at the Farnborough Air Show in the UK,Flight Intl. experts were shocked to see two different quality of manufacture,cruder MIG-29 when compared with the Flanker which was upto western stds.Though a MIG-29 today costs half that of a Flanker,the Russians after long experience found that the heavier fighter ultimately gave more bang for the buck with greater range,endurance,payload,etc.The smaller ,though very capable MIG-29 is more useful for building up numbers,where greater numbers in the inventory is required.The SU-34 tactical bomber derivative,is touted at staying aloft for 24 hrs.

Now the US is tasking the ultra-expensive fragile JSF for the close support role performed by the A-10.In the current Syrian conflict,the most useful aircraft in the sky has been found to be the virtually indestructible SU-25 dating back to the Soviet era.With the pilots and key components protected in by titanium panels,and its v.heavy payload ,it is having a decisive edge on the battlefield.We can't expect the AMCA to perform that role too.So where does it fit in the IAF's order of battle and how many does it expect to manufacture? It is here that the LCA suitably upgraded with some stealth " additives",better crew protection,etc., can really make a difference built in the hundreds.It could obviate the need of a more expensive med sized fighter.We need to get the LCA into sqd. service asap in large numbers ,assess the aircraft's further potential and then take a final call on whether we need to possess med. sized replacements for the M2Ks and MIG-29US.

We lack a strategic bombing capability,and why the IAF has for decades stuck it head in the sand no one knows.The TU-22 was offered to us during the tenure of ACM PC Lal.He rejected it. If we are to seal the deal for the FGFA,then the AMCA with lesser capability becomes questionable.Instead,a larger stealth bomber which can carry an array of stand-off ASMs is a more relevant programme. At least a parallel programme should be initiated leveraging use of AMCA dev. thus far.

Kakarat · Post by **Kakarat** » 01 Sep 2016 14:13

Philip you missed this picture from the link showing the weapons bay, it looks similar to the F-22's bay rather than that of PAKFA

Though this picture is not new there are more older ones showing similar configuration

We should stop discussing this any further here and move to AMCA News and Discussions

Indranil · Post by **Indranil** » 01 Sep 2016 23:02

Philip wrote:With the engines so closely spaced,what room is there for internal weapons?

Only the PAKFA and YF-23 have that arrangement.

Philip wrote: Will the AMCA be able to carry the planned BMos-M internally and still have room for AAMs?

No fighter aircraft will be able to carry the BMos-M internally.

Now the US is tasking the ultra-expensive fragile JSF for the close support role performed by the A-10.In the current Syrian conflict,the most useful aircraft in the sky has been found to be the virtually indestructible SU-25 dating back to the Soviet era.With the pilots and key components protected in by titanium panels,and its v.heavy payload ,it is having a decisive edge on the battlefield.We can't expect the AMCA to perform that role too.So where does it fit in the IAF's order of battle and how many does it expect to manufacture?

JSF taking on the role of the A-10 is plain stupid. Yes sir, I called it so. Theire were high performance jets even before the A-10/Su-25s existed. There is a reason the A-10s and Su-25s were designed the way they are inspite of "higher" performance jets being available. Basically, the Americans are stuck with the JSF for now. Using it for the A-10s is a bit of a stretch and they know it.

Until now the IAF has only foreseen strike roles in the immediate neighborhood which is heavily guarded. Hence they haven't gone for strategic bombers which are vulnerable. Instead they want the long ranges heavy fighters for the job. The FGFA does not obviate the AMCA which does not in turn obviate the LCA. If there was infinite wealth, we could have had just one kind of heavy stealth fighter one kind of heavy stealth strike platform. But we can't afford it. We, like every other AF have to balance numbers with capabilities. For a 1000 fighter fleet, only 100-odd should heavy fighters, 300 medium and 600 light. and I agree with you. Now that ADA has breathing space with the Mk1 and Mk1A orders, I would have loved Mk2 to be a little more stealthy: retain the wing and there is no need for any internal weapons carriage facility. Just replace the tail with two all moving canted tails, and shape the fuselage and intakes for a more stealthier profile.