LCA Tejas: News and Discussions

SaiK · Post by **SaiK** » 01 Oct 2015 17:44

The IOC/FOC process must be in Agile mode at the start of integrating an LRU. Let the FOC process happen! please.

IOW, IAF team must participate as stakeholders in design, dev for better ops programming.

We can't ignore operational requirements for a product.

--

maitya, what metal is that spar?

JTull · Post by **JTull** » 01 Oct 2015 17:48

HAL knows it has lost Rafale deal and it has cooked up Mk1A to keep itself relevant. Like the Artillery for IA, fighter shortage is a huge issue and aircraft from anywhere will be welcome, but I doubt HAL's intentions and ability to deliver on this.

I'd immediately split HAL into 3 companies with independent boards - Helicopter, Fighter Aircraft, Maintenance/MRO/Upgrades/ityadi - each with their R&D, Engineering and Manufacturing divisions and a Programme Management office. Then I'd align the Fighter R&D division with ADA and NAL before talking about Mk1A.

fanne · Post by **fanne** » 01 Oct 2015 18:03

I pray that GOI goes for one more private line if we are planning a more than 300 numbers. I would say pick Tata or L&T if willing (and not the bhai's or others, as we need a company that has 'culture' of R&D and not buying everything from outside).
Reasons
1.HAL is still reluctant. If you read between the lines, they would rather make HTT-40 than LCA). a GOI fiat goes only so far
2.We have had full lines at HAL for less than that number. Shamshers/Bahadur and Hawks all had prod run of less than 150. 300 numbers mean, two lines
3.If we cannot get Private player now, for our own product, then when?
4.Innovation and further development can only benefit for current and future jahaj

maitya · Post by **maitya** » 01 Oct 2015 18:28

SaiK wrote: <snip>
maitya, what metal is that spar?

At the risk of going complete tangential to the current discussion flow, pls do note that anal-ysis of mine had assumed UD CFC Spars which are all I-beam shaped.

The right-hand "un-finished" diagram actually was depicting 5 wing-boxes made of Spars of varying length and height (pls look closely) - the load-distn would be non-linear across these multiple wing-boxes.

The lay-man pov idea behind that anal-ysis was beak up the entire wing into "finite" elements (aka wing-boxes) and look at the load bearing components of each of them vis-à-vis the strength the spars of each of these boxes bring into play. Just for the heck of it I also assumed each of these wing-boxes is basically 3-spar design.

Pls note these kind of assumptions are ok to be made in all such anal-ysis in a forum like this - not for serious structural analysis etc (for which various tools are available etc), doing which obviously would be out-of-scope for a forum like this.

Actually the accompanying write-up (~4K words) first tries to do a single wing-box wing structural analysis (similar layout that you'd find in civilian aircraft wings) and then knock it down by pointing out the absurdities of various assumptions made.
And then break up the delta-wing structure into smaller sub-wings and use the same anal-ysis/calc methodology above , and then finally integrate all of them together - phew!! Ofcourse all of with some very outrageous assumptions and in layman pov.

The first part was over long back (Jun timeframe) but never got the required bandwidth and do the second part (the breaking up of the delta wing into smaller sub-wings and the necessary calc/anal-ysis).

chaanakya · Post by **chaanakya** » 01 Oct 2015 18:56

LCA MK-1A is what BRF designated as LCA MK 1.5 in previous pages. Mostly , consensus is on setting up full production line by HAL with private industries forming part of component suppliers. ( May be they can later graduate to full production of some variants e.g special ops version, IA version or export version with royalty to ADA/HAL/GOI). Capacity of 40/year seems optimal. Producing abt two sqdrns worth plane we get to target 7 sqdrns in 3.5years( rings familiar, 3.5 Friends of Bakis). By that time HAL should amortise the cost of setting up the assembly unit and private suppliers setting up spares supply unit. Thereafter it is quite cost effective for all the players in this. I also feel/suggest that development cost should also get amortised. Thereafter Assembly line come free.

ADA could get license fee/Royalty which can be used for further development , engines, advanced materials, avionics and export version of aircraft , which I am sure countries like Vietnam and Thailand , to name few, would be interested in procuring. We can advance LT Loans for its purchase to such countries.

I mean , if we have long term vision , we can plan lot of things. We can also send few planes to Syria to test it in actual war conditions like Rafale did or do some peacekeeping in Africa.

For force level planning , we need to keep in Mind the possibility to fight 2.5 front war. Pakistan China and Indian Ocean. While 7 sqdrns is good to begin with, we need to aim for more in basic or mainstay fighter planes.Like all sqdrns of MIG 21/Bis replaced with LCA.

Karan M · Post by **Karan M** » 01 Oct 2015 19:05

The original idea was to accept the A/C as is, and take the advantage of the AESA/EW as the + for performance. Somewhere (Shukla ji pranaam), HAL made the claim 800 kgs from the structure could be dropped ... and we have been wondering where, how, when.
Lets see if more reports emerge on this brilliance. What this would mean is the current undercarriage is very heavily overengineered. I can imagine a couple of 100 kilos - but 800?? Structural redesign entirely redone? Whats the difference between Mk2 and Mk1A then in effort?

ramana · Post by **ramana** » 01 Oct 2015 19:11

Austin wrote:Saurav Jha ‏@SJha1618 Sep 30

Uttam AESA is expected to be ready for airborne testing soon. Ground based testing has delivered encouraging results.

There'll be no IOC/ FOC campaign per se for the Mk-1A. The improvements will be made concurrently with the production process.

To attain that 400 figure a parallel line in the private sector is a must. This is being resisted by you know who.

IAF requirement for LCAs of different configurations is 400. This is the number people are talking about now.

All stakeholders are onboard with the Mk-1A configuration. Broad improvements: Uttam AESA, maintainability improvements, MAWS, DFCC Mk-2 etc

maitya and nileshjr, Looks like Skunk works approach in place for this phase.

See Kelly Johnson notes in Nicolai's book!

chaanakya · Post by **chaanakya** » 01 Oct 2015 19:13

The only difference I see is that FOC seems to be kicked out of the way, if true. MK2 will be next iteration of LCA Mk1 and MK1.5. Incremental approach, as BRF suggested. HAL could be thinking from engineering perspective rather than research and development perspective.

SaiK · Post by **SaiK** » 01 Oct 2015 19:54

maitya, asking the question from aam angle only. a ballpark number or value is enough to validate if the media reports are anywhere near proximity of 1000kg reduction. all we may know, it could be as simple as punching 2" holes in that spar and still maintaining sheer strength and MTOW capacity. so, FWIW is fine.

ManjaM · Post by **ManjaM** » 01 Oct 2015 20:24

1000kg is such a high number that if achieved it will drive significant stiffness variation from model. This in turn will cause internal load models to be in error and thus requiring FEM re-runs. I am certain the entire structure will need to be re-analyzed at that point and not just the areas that were touched.
Secondly, if you are taking strength and stiffened out from the production airplane that was there in the static and fatigue models, an assessment will have to be made if the tested articles envelope the production models. If not, you have a whole new set of issues to deal with.
Thirdly, to achieve the stated weight savings, the number of assemblies that will be touched will be high enough to entail a significant certification effort for new loads and new parts. Needless to say that takes time and manpower.
So the change of 1000kg is years of work depending on manpower. Even established big wigs will balk at a target like this. However, if HAL gets there, hats off to them.

Indranil · Post by **Indranil** » 01 Oct 2015 20:31

And I don't understand this no IOC/FOC for Mk1A either. If one has a plane which 1000 kgs lighter, with new structures, landing gear and potentially an altered CG, how can it commissioned without flight testing? It will be much shorter list of flight tests, but it has to be done.

ramana · Post by **ramana** » 01 Oct 2015 21:12

Flight tests will be done but no milestone tamasha.

deejay · Post by **deejay** » 01 Oct 2015 21:26

indranilroy wrote:And I don't understand this no IOC/FOC for Mk1A either. If one has a plane which 1000 kgs lighter, with new structures, landing gear and potentially an altered CG, how can it commissioned without flight testing? It will be much shorter list of flight tests, but it has to be done.

Indranil, certification with each change will have to be done. These may be achieved as production models get changed. No separate Mk1A programme but a step by step evolution, if I understood correctly.

Gyan · Post by **Gyan** » 01 Oct 2015 21:42

I can understand if DDM misinterpreted the whole thing. Perhaps HAL wants to say that LCA is 1000kg overweight and over a period of time producing 140 aircraft it can drop some weight.

But if HAL wants to drop all ballast 300kg, stick in AESA, new EW equipment, reduce the weight of landing gear as also achieve 1000kg weight reduction (overall), then it is simply impossible for HAL even if it hires foreign consultants and outsource everything including consultancy & component supply.

ramana · Post by **ramana** » 01 Oct 2015 21:48

We will let SJha ask the HAL folks and let us all know.

Vayutuvan · Post by **Vayutuvan** » 01 Oct 2015 21:53

Is there the exploded CAD design with parts weights for LCA available in open literature? If not a very detailed CAD to the level of nuts and bolts, at least at major sub assembly level? Or subsub assembly level?

SaiK · Post by **SaiK** » 01 Oct 2015 22:13

ManjaM wrote:..
So the change of 1000kg is years of work depending on manpower. Even established big wigs will balk at a target like this. However, if HAL gets there, hats off to them.

No! HAL must focus on production engineering and not design. HAL should stop talking like a designer, but purely integrator. Now, they can definitely participate design architecture concerning integration of components, etc. nothing more than that.

ADA, NAL and their labs must retain that work.

SaiK · Post by **SaiK** » 01 Oct 2015 22:19

ramana wrote:Is there a cutaway sketch of LCA like Flight Intl provides on some aircraft? I like to see where the gun is empalced.

answering my own ?

http://img7.imageshack.us/img7/4035/escaneo001.jpg

Under engine intake.

(#38) LRUs are above the gun.

Hence requal.

anyone know what happened to this pic?

SaiK · Post by **SaiK** » 01 Oct 2015 22:43

vayu dev, that would be raw ajint task to get. your PRANA and my AUTOLAY will be out.
but check some aspects in this video https://www.youtube.com/watch?v=vRf4Xr_G6Lk

PratikDas · Post by **PratikDas** » 02 Oct 2015 01:48

SaiK wrote:
ramana wrote:Is there a cutaway sketch of LCA like Flight Intl provides on some aircraft? I like to see where the gun is empalced.

answering my own ?

http://img7.imageshack.us/img7/4035/escaneo001.jpg

Under engine intake.

(#38) LRUs are above the gun.

Hence requal.
anyone know what happened to this pic?

Probably the same as this:

sankum · Post by **sankum** » 02 Oct 2015 01:53

The landing gear weight in a modern fighter is 4% while in earlier gen fighter used to be 7% of MTOW.

If we take 3% as possible weight reduction it comes at 400Kg at MTOW of 13.3T.

The rest 300-400 Kg weight reduction has to come from Airframe if the target of 700-800Kg is feasible.

It is only possible if the Airframe is also overweight.

Aditya G · Post by **Aditya G** » 02 Oct 2015 02:01

They can shave off some weight by redistributing internal components and eliminating lead dead weights.

Vayutuvan · Post by **Vayutuvan** » 02 Oct 2015 02:47

Optimization of the wing subsubassemblies (replicated components) using better performing composites is one way to do it. It is not rerunning of FEM/CFD models but they have to be run several times over using design of experiments. This is possible only if they redo all the CAD models with a few properties parametrized. One cannot have too many parameters even of they are continuous. Even a few discrete parameters can be a killer in terms of simulation turn around times and finding the optimal/near optimal structure.

One has to start somewhere, start getting operational data and then feed it to the CAD model parametrization and optimization loop on top of the lower level FEM/CFD.

SaiK · Post by **SaiK** » 02 Oct 2015 03:38

The engine alone weighs around 1T. not much you can shave unless GE specs point it is not already nickel based super alloys.

may be we need to look at graphene, silcon carbide where ever we can. dunno if spider silk can be synthesized yet for applications.

shiv · Post by **shiv** » 02 Oct 2015 05:23

SaiK wrote:vayu dev, that would be raw ajint task to get. your PRANA and my AUTOLAY will be out.
but check some aspects in this video https://www.youtube.com/watch?v=vRf4Xr_G6Lk

This video shows the simulation and software used in YellSeeYay
https://www.youtube.com/watch?v=755G4aqQ9mk

hanumadu · Post by **hanumadu** » 02 Oct 2015 06:48

The landing gear is aft of the centre of gravity of the plane. If landing gear weight reduces, doesn't it mean the ballast in the nose has to be reduced too?

sankum · Post by **sankum** » 02 Oct 2015 17:32

Parrikar cuts Gordian knot to boost Tejas line

By Ajai Shukla

The IAF had earlier agreed to buy another 20 Tejas Mark I, once the fighter obtains “final operational certification”, a much-delayed landmark expected in early 2016. It is unclear whether that order will stand, or be integrated into the proposed order for 80 Tejas Mark 1As.

Parrikar calculates that, with an order for 100 Tejas in hand, HAL will have the business case for quickly boosting production to at least 16 fighters per year.

The defence ministry calculates that a 100-Tejas order is essential to keep it working to capacity till 2022-23.

The Tejas Mark I was to have an “on-board EW system”, but lacks the space for one. It has, therefore, been decided to develop an EW pod for the Mark 1A, which will be carried externally under the fighter’s wing.

suryag · Post by **suryag** » 02 Oct 2015 17:49

The above article carefully skirts around the weight reduction ideas, focusses more on spj which makes me doubt the 1000kg/lb reduction. Knowing mp, his background and his sharp mind don't think he would have bought the 1k reduction idea if there were no substance. Btw, the sp2 is now acquiring mythical status

Karan M · Post by **Karan M** » 02 Oct 2015 18:11

sankum wrote:Parrikar cuts Gordian knot to boost Tejas line

By Ajai Shukla
The IAF had earlier agreed to buy another 20 Tejas Mark I, once the fighter obtains “final operational certification”, a much-delayed landmark expected in early 2016. It is unclear whether that order will stand, or be integrated into the proposed order for 80 Tejas Mark 1As.

Parrikar calculates that, with an order for 100 Tejas in hand, HAL will have the business case for quickly boosting production to at least 16 fighters per year.

The defence ministry calculates that a 100-Tejas order is essential to keep it working to capacity till 2022-23.

The Tejas Mark I was to have an “on-board EW system”, but lacks the space for one. It has, therefore, been decided to develop an EW pod for the Mark 1A, which will be carried externally under the fighter’s wing.

Finally, a sensible Raksha Mantri and a legitimate article. Note how quickly the IAF has got behind the 80 a/c case after a firm RM.

No quote about fancy 2000 lb reduction etc either. Fair enough.

A dedicated external EW pod is a great idea and one has to wonder at the stupidity in MOD circles till date that such a straightforward measure was not proposed.

JayS · Post by **JayS** » 02 Oct 2015 18:12

NO mention of AESA/1000kg weight reduction?? Apart from external RW pod, aren't other things such as IFR, Python/Derby integration part of FOC already?? Just adding external RW pod and rearranging some stuff around is not very significant change as compared to what we have been considering from previous news items.

I am not complaining, even this is a good step towards having incremental development program though. Whatever keeps the ball rolling. As long as IAF has large number of MK1s and MK2 arrives on time, all iz well..!!

JayS · Post by **JayS** » 02 Oct 2015 18:16

Karan M wrote:
Finally, a sensible Raksha Mantri and a legitimate article. Note how quickly the IAF has got behind the 80 a/c case after a firm RM.

No quote about fancy 2000 lb reduction etc either. Fair enough.

A dedicated external EW pod is a great idea and one has to wonder at the stupidity in MOD circles till date that such a straightforward measure was not proposed.

Karan, my factual knowledge of avionics is next zero. So please tell me, don't we have external RW pod already available from other systems such as Su-30MKI, which could be used on LCA?? Developing dedicated pod for LCA is good but that can be done side-by-side and would not hold entire program at bay.

Karan M · Post by **Karan M** » 02 Oct 2015 18:17

>>NO mention of AESA/1000kg weight reduction??
Weight reduction will be there - ballast in nose removed (perhaps elsewhere too; overall ballast per reports is 300 kg), but will be offset by greater weight of AESA. EW pod external is a good idea since it doesn't add more weight to the base fighter config. The Litening pod pylon (8th pylon) can be used for EW pod.
What is clearly not a "given" is the 800 kgs from structure etc.

chaanakya · Post by **chaanakya** » 02 Oct 2015 18:20

sankum wrote:Parrikar cuts Gordian knot to boost Tejas line

By Ajai Shukla
The IAF had earlier agreed to buy another 20 Tejas Mark I, once the fighter obtains “final operational certification”, a much-delayed landmark expected in early 2016. It is unclear whether that order will stand, or be integrated into the proposed order for 80 Tejas Mark 1As.

Parrikar calculates that, with an order for 100 Tejas in hand, HAL will have the business case for quickly boosting production to at least 16 fighters per year.

The defence ministry calculates that a 100-Tejas order is essential to keep it working to capacity till 2022-23.

The Tejas Mark I was to have an “on-board EW system”, but lacks the space for one. It has, therefore, been decided to develop an EW pod for the Mark 1A, which will be carried externally under the fighter’s wing.

May be I am wrong, but my understanding was that 40 LCA MK1 was already ordered by IAF in IOC-2 config.
This 7 sqdrs totaling 140 is for MK-1A . That makes it to total of 180 LCA.

Since there is no official release on these numbers we have to just go by tweets etc. Speculation , it could be.

I feel 16/PA is too low a figure. Namo likes to do it on "Grand Scale" in the Grand Scheme of things. I hope it is 40/year and that HAL is up to it. Else involve private players and ask them to pitch in as primary producer. That would give HAL a run for their money and time.

Karan M · Post by **Karan M** » 02 Oct 2015 18:22

nileshjr wrote:
Karan M wrote:
Finally, a sensible Raksha Mantri and a legitimate article. Note how quickly the IAF has got behind the 80 a/c case after a firm RM.

No quote about fancy 2000 lb reduction etc either. Fair enough.

A dedicated external EW pod is a great idea and one has to wonder at the stupidity in MOD circles till date that such a straightforward measure was not proposed.
Karan, my factual knowledge of avionics is next zero. So please tell me, don't we have external RW pod already available from other systems such as Su-30MKI, which could be used on LCA?? Developing dedicated pod for LCA is good but that can be done side-by-side and would not hold entire program at bay.

There is the EL/L-8222 SPJ. We could have used this, especially since more pods could be available from the Su-30 fleet and can always be ordered. If it can be used for the MiG-27, it can be used for the LCA. It just shows how such relatively minor issues were being used to delay and obfuscate the LCA program with MOD a willing participant in the fracas.

I have a term for these sort of conditions. Artificial scarcity. In which, a situation is created when a local program or simple alternatives are deliberately held up, so as to create an artificial crisis situation to justify expensive imports. A similar case was created with the FSAPDS program. First Army did not progress with DRDO local designs of FSAPDS, leading to those programs being stuck in limbo. That was only progressed once crisis became known. Too late. Next, Rheinmetall a possible collaborator for future programs was banned. Then IMI was banned - negating current source for FSAPDS. No progress in proper local manufacture of IMI TOT as well. Meanwhile, MOD rushed an emergency procurement for near obsolete Russian FSAPDS at 3x current price citing urgency. Typical case of how the "system" works to create a crisis and then "solve" it via imports.

Karan M · Post by **Karan M** » 02 Oct 2015 18:33

chaanakya wrote:May be I am wrong, but my understanding was that 40 LCA MK1 was already ordered by IAF in IOC-2 config.
This 7 sqdrs totaling 140 is for MK-1A . That makes it to total of 180 LCA.

Since there is no official release on these numbers we have to just go by tweets etc. Speculation , it could be.

I feel 16/PA is too low a figure. Namo likes to do it on "Grand Scale" in the Grand Scheme of things. I hope it is 40/year and that HAL is up to it. Else involve private players and ask them to pitch in as primary producer. That would give HAL a run for their money and time.

Reports were that first 20 IOC config, 2nd 20 FOC. Then before retiring the prior ADA head said 38 would be FOC config. But we don't know if the earlier orders were changed to this. Current report states that 60 new LCAs in FOC config - jingo khush hua.
IAF was busy stating they would only order 80 new Mk2s. Now Mk2 program is in addition.

suryag · Post by **suryag** » 02 Oct 2015 18:40

Karanm ji don't get me wrong but the weight of the pod needs to be accomodated by the pylon, we don't know if this is possible, we also don't know if the interfacing/electrical requirements can be met by lca systems.

The bigger question however is if the in20 engine is still in production as we might need 200 of these and wherever is the sp-2/3

JayS · Post by **JayS** » 02 Oct 2015 18:42

Karan M wrote: There is the EL/L-8222 SPJ. We could have used this, especially since more pods could be available from the Su-30 fleet and can always be ordered. If it can be used for the MiG-27, it can be used for the LCA. It just shows how such relatively minor issues were being used to delay and obfuscate the LCA program with MOD a willing participant in the fracas.

I have a term for these sort of conditions. Artificial scarcity. In which, a situation is created when a local program or simple alternatives are deliberately held up, so as to create an artificial crisis situation to justify expensive imports. A similar case was created with the FSAPDS program. First Army did not progress with DRDO local designs of FSAPDS, leading to those programs being stuck in limbo. That was only progressed once crisis became known. Too late. Next, Rheinmetall a possible collaborator for future programs was banned. Then IMI was banned - negating current source for FSAPDS. No progress in proper local manufacture of IMI TOT as well. Meanwhile, MOD rushed an emergency procurement for near obsolete Russian FSAPDS at 3x current price citing urgency. Typical case of how the "system" works to create a crisis and then "solve" it via imports.

Thanks for the info. I have always held an opinion that LCA should have been inducted at IOC itself - a firm order of 4-5 squadron. It would take 5-6 years for IAF to assimilate LCA and include it in their doctrine with operational readiness levels. In that time all this other things between IOC-to-FOC could have been done (of coarse a plane would have needed to upgrade already produced jets to latest standard, but that's life in Aerospace field). All the changes, to big to fit in above steps could have been pushed to MK2 with target of 2020.

I, personally, hold MoD (and GOI in general) for failure of the programs. It was their responsiblity to ensure all stake holders - IAF, ADA, HAL - work with synergy. Fat masters tend to have fat dogs is what my observation. No point in blaming the dogs when the masters never take them out for require exercise.

Yagnasri · Post by **Yagnasri** » 02 Oct 2015 18:50

Alert - Mango post:

May be they will look into wight reduction which can be done without many issues and make it as Mk1A. They will come out fast now. Even if the wight is reduced say 400-500 Kg then it will improve the the performance. Right?

It is quire possible that they are just saying 1000 Kgs to get the deal and later say sorry we can do only 500 kg. We all know how PSU defense fellows make large promises and later say sorry. But once some improved performance is assured in Mk1 in the form of Mk1A I am sure IAF will be on board.

May be HAL is not the one that is pushing for this. May be MP is pushing it as part of MII.

chaanakya · Post by **chaanakya** » 02 Oct 2015 18:52

Karan M wrote:
chaanakya wrote:May be I am wrong, but my understanding was that 40 LCA MK1 was already ordered by IAF in IOC-2 config.
This 7 sqdrs totaling 140 is for MK-1A . That makes it to total of 180 LCA.

Since there is no official release on these numbers we have to just go by tweets etc. Speculation , it could be.

I feel 16/PA is too low a figure. Namo likes to do it on "Grand Scale" in the Grand Scheme of things. I hope it is 40/year and that HAL is up to it. Else involve private players and ask them to pitch in as primary producer. That would give HAL a run for their money and time.
Reports were that first 20 IOC config, 2nd 20 FOC. Then before retiring the prior ADA head said 38 would be FOC config. But we don't know if the earlier orders were changed to this. Current report states that 60 new LCAs in FOC config - jingo khush hua.
IAF was busy stating they would only order 80 new Mk2s. Now Mk2 program is in addition.

Either way , at least 100. I think that is a respectable number. But is there any FOC or just test while in Service?

Thanks for clarification.

Karan M · Post by **Karan M** » 02 Oct 2015 18:58

suryag wrote:Karanm ji don't get me wrong but the weight of the pod needs to be accomodated by the pylon, we don't know if this is possible, we also don't know if the interfacing/electrical requirements can be met by lca systems.

The bigger question however is if the in20 engine is still in production as we might need 200 of these and wherever is the sp-2/3

Are sir..please drop the ji.. You think all this wasn't done by Indian industry before...?

The MiG-27 carries an EL/L-8222. The MiG-21 Bison carries the same. The MiG-27 was even modified to carry an internal EW suite. As usual cancelled before full completion.

You can always modify the 8th pylon to carry an EW pod.
Litening is 208 kg. EL/L-8222 is 100 kg. You can even put in an aux generator in the indigenous pod if the all up draw is higher.

EL/L-8222 class pod can even be used by F-15s and Su-30 MKIs. Reason it was dropped from MKI was because of EMI/EMC issues with Russian avionics.

So, the bigger challenge will be EMI/EMC tests. About making sure the EW pod & the radar & RWR work in synch. About optimal coverage. But its doable.

The bigger question is why was a straightforward alternative not even explored till date? The answer is obvious. IAF didn't ask because it would obviate a - from the LCA which was a useful point to crib about Mk1 being insufficient and Mk2 as necessary. ADA/HAL didn't bother since Mk2 was in pipeline and they were comfortable with IAF deciding rather than being proactive. MOD of course, in prior iteration was all about imports or taking no decisions.

About IN-20 engines, place the order now and you will get them. Wait another buncha years and they will go out of production.