AMCA News and Discussions

kit · Post by **kit** » 30 Jan 2018 00:35

JTull wrote:
Kartik wrote:What exactly are we looking at SaiK?
Active (wide-band) radar absorbing skin!

http://publications.drdo.gov.in/ojs/ind ... view/12025

whoa

..lets coat that into lca s

..with already small rcs maybe it ll make it invisible

NRao · Post by **NRao** » 30 Jan 2018 01:17

kit wrote:
JTull wrote:
Active (wide-band) radar absorbing skin!

http://publications.drdo.gov.in/ojs/ind ... view/12025
whoa ..lets coat that into lca s ..with already small rcs maybe it ll make it invisible

Looks like it is a skin, not a paint.

From the pdf wrote: CONCLUSION

Four layers JA and capacitive JA are presented in this paper. The crucial spacecloths of JA are realised as hexagonal resistive grid networks on electrically thin substrates. The novelty of the design comprises design of spacecloths for realising desired surface resistivity, using a single 250 Ω/sq resistive sheet, totally eliminating lumped discretes and associated soldering related defects, assembly and undesired parasitic reactances. Using capacitive loading of the hexagonal resistive grid network of spacecloths, a capacitive JA with reduced thickness and extended absorption bandwidth is realised. A thickness reduction of 19.4 per cent as compared to a conventional JA and bandwidth increase of 19.1 per cent (142.8 per cent to 161.9 per cent) with 15 dB (minimum) absorption is realised in capacitive JA. Accurate RC layer design and implementation sans lumped discretes has enabled translation of design to airworthy hardware. Also, polarisation insensitive, UWB absorption of 15 dB combined with wide angle TE and TM performance is realised. The CJA is suited for air vehicle stealth applications especially for RCS reduction of wing leading edges.

1) This may explain - one of many - why the lack of interest in the FGFA. IF this research is productized, then the FGFA would have an inferior method for RCS. Note that this would/should be able to provide a 360 coverage, the FGFA will not have the same level. ??????? Just my speculative take
2) The AMCA should be a true 5th Gen plane - a computed solution, ground up.

3) I would prefer to design a single engine 5th Gen craft

Eric Leiderman · Post by **Eric Leiderman** » 30 Jan 2018 04:06

A single engined stealth aircraft has limitations as far as internal stores are concerned. (F35 case in point)
The ideal solution is the Medium sized aircraft AMCA Mid 2030's
The larger FGFA late 2020's
LCA MKII with semistelth capabilities incorporation radar absorbtion materials and electronic radar deflection, to get its RCS below 0.5 m2 (late 2020's)

all 3 of the above are in some stage of planning and this in itself will be a stretch as far as money and resources are concerned.

Hopefully we grow at 10 % commencing 2020's with a defence budget at 2.5 %of GDP and a reasonable goverment is in charge.
If these three aircraft are in different stages of squadron strength in the 2030's we will be in a position to hold our own in a regional conflict depending on the numbers inducted.

By that time we will have a fairly large pool of indian pilots in higher rungs who are more inclined to look at the larger picture. As by then we will have five and six legged cheethas.

Rishi_Tri · Post by **Rishi_Tri** » 30 Jan 2018 05:37

ashishvikas wrote:Update from Saurav Jha :

ADA has already received the full-scale air intake duct for the AMCA's 3B-09 design version from NAL.

https://twitter.com/SJha1618/status/957926082056929280

We have seen number of images of air intake duct. Have they also created fuselage, wings, rudder etc.? Or is it only air intake duct for the time being.

JTull · Post by **JTull** » 30 Jan 2018 11:42

Without an engine selection, what good is an air intake other than a theoretical exercise.

JTull · Post by **JTull** » 30 Jan 2018 14:40

kit wrote:
whoa ..lets coat that into lca s ..with already small rcs maybe it ll make it invisible

Even without active absorbant, we should consider testing a skin on one of the LCA PVs or strike aircraft like Su-30 MKIs/Jags or perhaps even the Hawk to hide the rivets and joints. We've many HAL made aircraft of which one can be used for testing. It'll de-risk such an attempt directly on AMCA.

Technology to install this and understanding subsequent maintenance issues are very important.

Prasad · Post by **Prasad** » 30 Jan 2018 14:49

Heck, we could take one of the decomissioned Migs and try them out

RKumar · Post by **RKumar** » 30 Jan 2018 14:50

JTull wrote:Without an engine selection, what good is an air intake other than a theoretical exercise.

There are already some GE-414 delivered if I am not mistaken

JTull · Post by **JTull** » 30 Jan 2018 16:10

RKumar wrote:
JTull wrote:Without an engine selection, what good is an air intake other than a theoretical exercise.
There are already some GE-414 delivered if I am not mistaken

That assumes GE-414 has already been selected for AMCA!

RKumar · Post by **RKumar** » 30 Jan 2018 16:47

^This is the logical choice at this moment. Due to commonality with LCA MK2.

Kaveri is not mature.

Russian engine could be other choice but I guess is not preferred.

Getting engine from Europe is another choice but will take years.

What else is available??

NRao · Post by **NRao** » 30 Jan 2018 19:41

JTull wrote:
kit wrote:
whoa ..lets coat that into lca s ..with already small rcs maybe it ll make it invisible
Even without active absorbant, we should consider testing a skin on one of the LCA PVs or strike aircraft like Su-30 MKIs/Jags or perhaps even the Hawk to hide the rivets and joints. We've many HAL made aircraft of which one can be used for testing. It'll de-risk such an attempt directly on AMCA.

Technology to install this and understanding subsequent maintenance issues are very important.

IF I understand it correctly (F-22 and F-35), the "skin" is not an add-on. The "skin" is the body/frame of the craft. It will demand a new method of building the frames -essentially the one for the LCA will not do. That is my understanding.

By now they were supposed to have sent a full scale model for RCS testing. Have not found any mention in open source - yet - on where they stand on this matter.

I think they have made good progress on this front. Just a gut feel.

srin · Post by **srin** » 30 Jan 2018 22:26

This skin that they are talking about is 1 inch thick (24.8mm), and my understanding is that aircraft skin is very thin (less than 1 cm). So, not too sure about the feasibility part.
Also, look at the angle of incidence requirement - so the aircraft will need shaping to avoid 90 degree incidence ?

brar_w · Post by **brar_w** » 30 Jan 2018 22:34

RCS is not the only specification in the trade space for high performance fighter system. Weight, complexity (manufacturing and cost) and the ability to survive repeated supersonic flight is another. There are different applications where thicker RAM or a heavier solutions can be used such as UAV's and Bombers.

NRao · Post by **NRao** » 30 Jan 2018 22:51

Whole lot on "Stealth": viewtopic.php?f=3&t=7241&start=40#p2185279

On "skin", in particular: viewtopic.php?f=3&t=7241&start=40#p2185285

Kartik · Post by **Kartik** » 31 Jan 2018 01:04

JTull wrote:
RKumar wrote:
There are already some GE-414 delivered if I am not mistaken
That assumes GE-414 has already been selected for AMCA!

For all practical purposes, it has been selected as the engine for the first stage of the program, which is till the 4th prototype. They will need to then collaborate with the engine manufacturer on the 110 kN class engine for the production variants. If its going to be the F-414 then there are possibilities for the higher thrust variant. if its going to be a Kaveri-M88 variant then they will need to get it into one of the prototypes well before that, to get it tested and validated.

From ADA's annual report

AMCA latest Configuration and development approach are accepted by IAF. First two/three prototypes will fly with proven 90kN class engine and 110 kN
class engine will be installed in a phased manner from 4th prototype onwards. PSQR is being amended by IAF towards finalization.

and the IAF clearly has specified a 110 kN thrust engine for the AMCA production variants. the Kaveri-M88 was not mentioned, but it could be a possibility if that program actually does progress to such a level.

11.4 Powerplant:

It has been communicated by Air HQ that the AMCA should be powered by 110 kN class engine. GE, Euroject and Rolls Royce have proposed G-G route for AMCA powerplant. A final decision is awaited.

Cybaru · Post by **Cybaru** » 31 Jan 2018 01:15

Kartik wrote:
if its going to be a Kaveri-M88 variant then they will need to get it into one of the prototypes well before that, to get it tested and validated.

From ADA's annual report

AMCA latest Configuration and development approach are accepted by IAF. First two/three prototypes will fly with proven 90kN class engine and 110 kN
class engine will be installed in a phased manner from 4th prototype onwards. PSQR is being amended by IAF towards finalization.

Good find Kartik,

I think kaveri-M88 will end up for LCA mk1/mk1a and perhaps even Rafales if we purchase/manufacture more.

I think Eurojet EJ200 which had an extra 30% growth left in it is being worked at GTRE also. Not sure what the whole story there is completely, but given the growth margins, it fits the AMCA/LCA mk2 requirements well. It can also be good replacement for our MKI as it is in the same power range and have TVC as well.

From wiki

EJ2x0
Stage 1:

The EJ2x0 with 20% growth compared to the original EJ200. The EJ2x0 engine will have dry thrust increasing to some 72 kN (or 16,200 lbf) with a reheated output of around 103 kN (or 23,100 lbf).[12]

Stage 2:

The new engine plan to increase the output 30% more power compared to the original EJ200. The engine will have dry thrust of around 78 kN (or 17,500 lbf) with a reheated output of around 120 kN (or 27,000 lbf).[12]

Cybaru · Post by **Cybaru** » 31 Jan 2018 01:25

I think this is the time that IAF forgoes this light/medium/heavy category and pushes AMCA to take care of all its medium to heavy needs. There won't be an opportunity to do a heavy one later. They better ask for 8-10K kgs fuel and 3-5K internal carriage of munitions in this puppy.

Rakesh · Post by **Rakesh** » 31 Jan 2018 06:54

cybaru: excellent point. +108 to you! Some more news for the import lobby to get worried...

https://twitter.com/sjha1618/status/958321753457008640 ---> And in really good news for indigenization, note that MIDHANI is setting up an integrated carbon fiber plant which will also have a 100 ton per year aerospace grade carbon fiber prepeg line using technology from NAL.

Cybaru · Post by **Cybaru** » 31 Jan 2018 08:24

Do we know what the internal fuel for AMCA is planned?

Gagan · Post by **Gagan** » 06 Feb 2018 00:56

What I am saying is that with 2 x GE 414s, the AMCA is a FA-18 sized fighter.
But with the added demands of a bigger body for internal carriage.
And then if you want it to supercruise ...

I suspect that the 414 might leave it under powered

nachiket · Post by **nachiket** » 06 Feb 2018 01:06

Gagan wrote:What I am saying is that with 2 x GE 414s, the AMCA is a FA-18 sized fighter.
But with the added demands of a bigger body for internal carriage.
And then if you want it to supercruise ...

I suspect that the 414 might leave it under powered

The GE 414 EPE version is supposed to up the thrust to almost 110kN. If you want to go bigger than that, you'll be in AL-31/PW-F100 territory. The AMCA will have to be called the AHCA then I guess.

Cybaru · Post by **Cybaru** » 06 Feb 2018 01:13

nachiket wrote: The GE 414 EPE version is supposed to up the thrust to almost 110kN. If you want to go bigger than that, you'll be in AL-31/PW-F100 territory. The AMCA will have to be called the AHCA then I guess.

It shouldn't matter what/how the nomenclature changes. AMCA should be medium to medium-heavy category.

It would be nice if the aim of AMCA is to deliver 2-3k pounds to 1000 kms radius. (10K kgs of fuel and 1.5K kgs of payload)

If the above becomes true, our dependence on PAKFA gets reduced drastically. It may require 2 AMCA where one PAKFA would be required, but heck our birds will have much higher uptimes and better as far as MMI (man-machine interface) is concerned.

NRao · Post by **NRao** » 06 Feb 2018 03:44

Gagan wrote:What I am saying is that with 2 x GE 414s, the AMCA is a FA-18 sized fighter.
But with the added demands of a bigger body for internal carriage.
And then if you want it to supercruise ...

I suspect that the 414 might leave it under powered

The GE F414 INS6, @ 98 kN, would suffice for the AMCA. The 110 kN (an uprated GE F414 INS6) is an insurance. The first 4 prototypes are supposed to be powered by the GE F414 INS6.

nachiket · Post by **nachiket** » 06 Feb 2018 11:53

Cybaru wrote:
nachiket wrote: The GE 414 EPE version is supposed to up the thrust to almost 110kN. If you want to go bigger than that, you'll be in AL-31/PW-F100 territory. The AMCA will have to be called the AHCA then I guess.

It shouldn't matter what/how the nomenclature changes. AMCA should be medium to medium-heavy category.

It would be nice if the aim of AMCA is to deliver 2-3k pounds to 1000 kms radius. (10K kgs of fuel and 1.5K kgs of payload)

If the above becomes true, our dependence on PAKFA gets reduced drastically. It may require 2 AMCA where one PAKFA would be required, but heck our birds will have much higher uptimes and better as far as MMI (man-machine interface) is concerned.

Those engines are larger and heavier and use more fuel. You are looking at at least an F-15 sized aircraft in that case. And then people will complain that an aircraft that size needs engines as powerful as those on the F-22 or the new one on the PAKFA to be termed 5th gen.

SaiK · Post by **SaiK** » 06 Feb 2018 18:42

brar_w wrote:RCS is not the only specification in the trade space for high performance fighter system. Weight, complexity (manufacturing and cost) and the ability to survive repeated supersonic flight is another. There are different applications where thicker RAM or a heavier solutions can be used such as UAV's and Bombers.

Correct.. but we have solutions too if we think about our LCA nosecone how it permeates (although failed and we have to choose Cobham quartz on attenuation issues). If kevlar composites can take to mach 4 levels (derated for discussion), we are talking stealth.

Just like Sadguru says, it is "inner engineering*

all subcutaneous.

BTW, if someone does considers this option there are caveats. please note S-band and >19ghz absorptions. We still have to work on the exterior skin for <3ghz and >19ghz.

Cybaru · Post by **Cybaru** » 07 Feb 2018 03:30

nachiket wrote:
Cybaru wrote:

It shouldn't matter what/how the nomenclature changes. AMCA should be medium to medium-heavy category.

It would be nice if the aim of AMCA is to deliver 2-3k pounds to 1000 kms radius. (10K kgs of fuel and 1.5K kgs of payload)

If the above becomes true, our dependence on PAKFA gets reduced drastically. It may require 2 AMCA where one PAKFA would be required, but heck our birds will have much higher uptimes and better as far as MMI (man-machine interface) is concerned.
Those engines are larger and heavier and use more fuel. You are looking at at least an F-15 sized aircraft in that case. And then people will complain that an aircraft that size needs engines as powerful as those on the F-22 or the new one on the PAKFA to be termed 5th gen.

Actually no, that's not what I am saying.I think you know what I am trying to say, I just didn't say it properly. Generally you have something like this

Empty Weight F/A-18E: 32,100 lb (14,552 kg) Max Takeoff Weight 66,000 lb (29,937 kg)

The fuel/payload mix is roughly 15K.

Since we won't have opportunity to hang external drop tanks, I hope we design internal fuel tanks that can take about 10-12k kgs (12-16K liters of fuel). This way it will have same range as PAKFA but with a reduced internal payload maybe of only 1.5-2k kgs only. Even if we have to task far more number of AMCA for the same mission as pakfa, it will atleast be possible to perform those missions by reaching similar distances even without adding pakfa to the IAF roster. If we don't have large internal fuel tanks, then we have to add a plane like PAKFA with all its issues to our roster. Having larger fuel tanks add far more flexibility than not having them. It will push the aircraft size up a bit and make it a little less efficient aerodynamically, but it will allow us greater tasking capability and more disparate mission profiles.

The point is designing AMCA with very large internal fuel tanks will give us strategic leverage during acquisition of new assets, tasking of existing assets and may even eliminate the need for a heavy category completely. It can be our silver bullet for the future. I am happy to perhaps take a stab at providing more detailed thoughts around this.

Rakesh · Post by **Rakesh** » 18 Feb 2018 23:42

Coming Soon On Livefist

https://twitter.com/livefist/status/964880012317949952 --> Also this week on Livefist: a full status check on India’s AMCA fifth generation fighter program, at a time when China has begun inducting its own, India’s partnership with Russia falters & the US makes a renewed push of the F-35.

jaysimha · Post by **jaysimha** » 19 Feb 2018 18:00

https://www.ada.gov.in/currentdocs/EOI% ... 20NGTD.pdf

ADA/COM/IND/EOI/NGTD/2017-2018/SU Date: 16/02/2018

Aeronautical Development Agency is an autonomous Body setup under Ministry of Defence, Governmentof India for research and development of Indigenous Light Combat Aircraft (LCA), Tejas. 2. ADA is looking for vendors who can take up “Manufacture of the Next Generation Technology Demonstrator (NGTD)"

Proof positive that MRM has lighted the burners under everybody's seat...........

Gagan · Post by **Gagan** » 19 Feb 2018 18:13

Litening pod, pylons with missiles !
ADA already has plans for a non-stealth version.
Why is the litening pod not integrated into the body of the plane hain ji? Is it because the plane is too small and there is no space for it?

The IAF was having issues with lack of full spectrum stealth on the FGFA, will they be ok with this configuration hain ji?

Bharadwaj · Post by **Bharadwaj** » 19 Feb 2018 18:51

jaysimha wrote:https://www.ada.gov.in/currentdocs/EOI% ... 20NGTD.pdf

ADA/COM/IND/EOI/NGTD/2017-2018/SU Date: 16/02/2018

Aeronautical Development Agency is an autonomous Body setup under Ministry of Defence, Governmentof India for research and development of Indigenous Light Combat Aircraft (LCA), Tejas. 2. ADA is looking for vendors who can take up “Manufacture of the Next Generation Technology Demonstrator (NGTD)"

Proof positive that MRM has lighted the burners under everybody's seat...........

Looks like they are accelerating the timelines. Only three years for the td to roll out

sankum · Post by **sankum** » 19 Feb 2018 19:18

Three and half years for TD1 rollout and first flight and five and half year for completion of flight testing.

length-17.2m
span-11.13m
Wing area-50 sq.m

putnanja · Post by **putnanja** » 19 Feb 2018 20:38

jaysimha wrote:https://www.ada.gov.in/currentdocs/EOI% ... 20NGTD.pdf

ADA/COM/IND/EOI/NGTD/2017-2018/SU Date: 16/02/2018

Aeronautical Development Agency is an autonomous Body setup under Ministry of Defence, Governmentof India for research and development of Indigenous Light Combat Aircraft (LCA), Tejas. 2. ADA is looking for vendors who can take up “Manufacture of the Next Generation Technology Demonstrator (NGTD)"

Proof positive that MRM has lighted the burners under everybody's seat...........

Does this mean the design is frozen or at an advanced stage? Hope they release the final config soon.

JayS · Post by **JayS** » 19 Feb 2018 21:24

jaysimha wrote:https://www.ada.gov.in/currentdocs/EOI% ... 20NGTD.pdf

ADA/COM/IND/EOI/NGTD/2017-2018/SU Date: 16/02/2018

Aeronautical Development Agency is an autonomous Body setup under Ministry of Defence, Governmentof India for research and development of Indigenous Light Combat Aircraft (LCA), Tejas. 2. ADA is looking for vendors who can take up “Manufacture of the Next Generation Technology Demonstrator (NGTD)"

Proof positive that MRM has lighted the burners under everybody's seat...........

Quite an ambitious plan. One of my pet wish is fulfilling - a quick TD phase. Doable if files move fast enough. Otherwise T0 itself will take 5yrs to arrive. I see only HAL will be able to get it done. Hopefully HAL would give out sub-assemblies right from the TD phase to Tier-1 companies for them to gear up for FSED with significant sub-assembly level design responsibilities (even limited responsibility is good).

JTull · Post by **JTull** » 19 Feb 2018 22:50

Let AMCA TD-1 start taking shape and watch the paid press ridiculing crores being wasted on it while FGFA or F-35 are available for those cheap $billions.

Prasad · Post by **Prasad** » 19 Feb 2018 22:53

Gagan wrote:Litening pod, pylons with missiles !
ADA already has plans for a non-stealth version.
Why is the litening pod not integrated into the body of the plane hain ji? Is it because the plane is too small and there is no space for it?

The IAF was having issues with lack of full spectrum stealth on the FGFA, will they be ok with this configuration hain ji?

I'm sure brar saheb will bring in more information but one of the criticisms, drawbacks of the eots in the F-35 was questions about upgradability of the onboard system. An external pod is easier to upgrade than an internal system with its corresponding effect on stealth of course.

brar_w · Post by **brar_w** » 19 Feb 2018 23:03

Prasad wrote: I'm sure brar saheb will bring in more information but one of the criticisms, drawbacks of the eots in the F-35 was questions about upgradability of the onboard system. An external pod is easier to upgrade than an internal system with its corresponding effect on stealth of course.

The EOTS is an LRU and as long as you are within the same volume you can upgrade the sensor. In fact, Advanced EOTS is currently being developed and could be in flight testing in the next few months to a year. The upgrades convert the pod into a multi-spectral sensor by adding a second SWIR channel and adds other features as well so it is clear that there was margin for growth built in. Of course upgrading external pods will be easier but even there you are still limited by space, weight, and power unless you alter the physical dimensions of the pod. At the end of the day it is a trade off and if RCS is to be preserved for certain missions which require targeting pods then the most optimal solution from an RCS perspective would be to have them integrated.

Prasad · Post by **Prasad** » 19 Feb 2018 23:09

Yeah, so it just poses another set of design constraints just like an external one. Will be interesting if any chaiwallahs or panwalahs get to hear about development of an internal EOTS for amca by the yehudis.

Indranil · Post by **Indranil** » 20 Feb 2018 00:06

Hoot!!!! This made my say. And on top of that they chose my favorite looking model

I think they are going to sacrifice RCS on strike missions anyhow, so an external Litening pod does not bother me.

Indranil · Post by **Indranil** » 20 Feb 2018 00:15

sankum wrote: length-17.2m
span-11.3m
Wing area-50 sq.m

Nice ratios. Again going for low wingloading. I can see why they want 220-230 kN. It's amazing what Tejas has enabled.

Rakesh · Post by **Rakesh** » 20 Feb 2018 00:16

Indranil wrote:It's amazing what Tejas has enabled.

Thank You Sir for highlighting that. People need to understand this.