Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Cain Marko » 20 Nov 2019 09:33

Indranil wrote:NLCA Mk2 is being completely redesigned. It won't be Naval AMCA, but a twin engined NLCA Mk2. Frankly, I am confused and so is everybody I have talked to. Navy is firmly behind a twin engine bird designed by ADA called the TEDBF. There will be some reorganization in lieu of Mk1 nearing completion, onset of MWF production and testing, onset of final design phase of AMCA, Ghatak and now TEDBF. THings will get more concrete after the reorganization.
.

DAMN! I had said this ages ago. That the mk2 would never work for the Navy. The amount of flak I received for this!

Then I said that the mk2 should be twin engined. Received flak for this too.

I for one am happy that this tedbf is being thought of. Only regret is that they should've done it a lot earlier without considering the single engined Tejas as a possibility to begin with.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby LakshmanPST » 20 Nov 2019 09:54

When discussing the question, why no NAMCA, I guess we're missing a point here...
Navy is not looking for any new jet... They're looking for a jet that can replace MIG 29Ks in VikAd and Vikrant...
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From what I understand, Navy want early retirement of MIG 29Ks... So, they need a jet that can be operated from Vikramaditya and Vikrant... Both these carriers are STOBAR and both of them have small lifts that can accomodate only MIG 29K sized birds...
And for reasons best known to IN, they want a twin engine jet...
And operating Rafale-M or F/A 18 from these carriers is possible only with some jugaad...

I guess ADA might have studied NAMCA option and concluded that it won't be feasible to Navalize AMCA within the constraints of VikA & Vikrant...
So, the way ahead was to develop a new twin engine jet...

Developing another 5th Gen jet for Navy, when we have not yet mastered the technology will obviously be time consuming and costly...
Also, as already pointed out above, IN may not be needing a 5th Gen jet for the missions they envisage for their fighter arm in near future...
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Considering all these things, they would have decided to develop a new 4.5 Gen jet...
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I see TEDBF being operated from Vishal as well...
Total order may easily cross 100 jets...
Let's hope for the best...

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby chola » 20 Nov 2019 10:04

Every time I see that goofy acronym I think of Ted, the foul mouthed teddy bear.

Best of luck to the naval chaps with this project. I hope the lessons learnt in the NLCA project help hasten this one.

If the MiG-29K weren't such a goddam lemon, we would be anticipating the NLCA serving as complement to the Fulcrum. But the IN can't risk a single-engine too when the two-engine is unreliable.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 10:08

I have been spending some time on possible NLCA MK2 configs. I think its possible to convert NLCA MK2 to twin engine version with relative ease. MWF would be more tricky and would need a lot of aero testing. So its a no go IMO.

If you see the top view image I posted above, accomodating 2nd engine would extend wing by only a small length for maintaining same shape. Wing will definitely need folding. Should have tip mounted CCM.

If you see image below, the fuselage from below is is already wide enough if we include the side fairings, to accomodate second engine. It will need fattening of coarse and intakes enlarged to tice their curre t opening and moved out a bit. And wings can be moved out slightly, as I have done in my previous post, because we will need some margin for wing fuselage blending.
Image

But the length will have to be increased much more to maintain the fineness ratio, something like 16.5m, IMO. Nose will need some lengthening ahead of the intakes and tail should be extended a bit behind the wing TE. We will need much larger stabilators (would be helpful in manoeuvreability too).

It could have single VT with folding or twin VT. Single VT is easier with current topside wing fuselage blending and cetre dorsal spine retained with little changes. Twin VT will need fresh belnding with flattend top and canopy blended in witht the fuselage a la AMCA (as there wont be rear fairing turning into a spine anymore). The twin VT can be mounted on the side booms carrying the stabilators. But twin VT, I think will have aerodynamic issues due to vortex bursting from the delta wings. I tend to favor single large VT with folding (it will have to be rather large to be able to take one engine out condition).

I am approaching towards a bird with 16.5-17m length, close to 10m wing span, over 5m height for single VT. Increased lengnth and width of fuselage and larger wings should facilitate higher internal fuel at ~5-5.5T and accomodation of larger MLG. The broader and longer Fuselage can have 2 large or 3-4 smaller weapons stations. In addition 4 wing stations each (counting the CCM). Empty weight ~10T, clean TOW of around ~16T qnd MTOW ~23-24T.

If ADA thought the NLCA MK2 could even remotely meet NSQR at 17T MTOW with 1 F414, a 24T aircraft with 2xF414 should also be able to do it and in a better manner in fact.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby pushkar.bhat » 20 Nov 2019 10:25

My two pence on how these programs will play out.

I think we will have only two main programs. The Single engined Fighter (Light/Medium Weight) and a Twin engined program.

LCA MK2 or MWF Single engined fighter will be the first one and that is pretty much on its way to the project realization phase.

The twin-engined fighter program will have AMCA as the mainstay, the TEDBF will have platform commonalities except for the fact that it will be designed from day 1 for Naval Deck operations. This was crucial learning from the NLCA program when we learnt that the design naval operations will be very different from the characteristics for the Air Force.

My expectation is that the AMCA and TEDBF will share the same engine, cockpit layouts, Comm, Radar and even many weapon systems that we will integrate. Expect a difference in the external appearance, control surfaces, landing gears, control laws and therefore the entire performance envelope of the two fighters.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 10:31

Someone needs to tell me what exactly is the technical issue with NAMCA that it cannot be done in 15yr timeline, but a fresh TEDBE is doable.

Let me say this categorically, if ADA did not design AMCA with a Naval vereion in mind, I am disppointed with them. What did they learn from LCA - NLCA saga if they could not design AMCA from outset for navalisation..? And before anyone says, that would have been suboptimal design for the IAF which they would have rejected, let me point out that ADA can always design AMCA in a modular approach that F35 took for Naval version with cousin parts and modular inserts for larger wing. AMCA is suposed to have more power with lower MTOW than F35. I just dont see why NAMCA could not TO from ski jump with TWR of 26/20 or even 27/20 (assuming F414 engine) when NLCA MK2 was supposed to TO with 17/10 TWR...? In the Air, Naval versions are almost always more restricted in terms of manoeuvreability compared to their AF counterparts. This is true for Rafale M as well.

Lets say, Navalised AMCA was still inadequate, if Navy is OK with a 4.5G fighter they should have no issue with a stripped down AMCA naval with relaxed stealth and suoercruise requirements. So what exactly ADA thinks it cannot do and they will need a 4.5G fighter compulsorily..?

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby VikramA » 20 Nov 2019 10:51

I think TEDBF is going to be internally redesigned AMCA without the internal weapon bay like the KAI- KF-X.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 11:08

I saw some points in last couple of pages, to lazy too quote posts individually.

Pilot is important of coarse but so are machines which are worth of the order 100M a piece. We cant just keep losing them. There is a cost and performance trade off for any safety measures, whether for the Man or the Machine. Some are worth taking, some can be waived of by increasing reliability of mission critical systems. Please keep in mind that when an engine is fitted in a TE fighter it doesn't have all the redundancy systems that it would have when the same engine is fitted in a SE fighter. So TE fighter doesnt have 200% redundancy of SE fighter, so to speak. F404 was designed for TE application. It needed some design changes in its peripheral systems and FADEC for SE application.

French saying we will upgrade Rafake till 2070 doesn't meam it will remain relevent past 2070, or indeed even remain in service till then. Even though 4G platforms like Rafale, FA18, F16 will see service so many decades into the future, doesnt mean we should induct a 4G fighter in 2030s. All those countries have next gen platforms already available or in making. We don't. If the IN changed their key requirement abruptly from SE to TE within last decade, what it the guarantee they will not change their req to 5G from 4/4.5Gin next one decade..? What will we do then..? Start afresh?

The preference that Navies have for Twin engine for additional safety is known for over 50yrs now. The argument based on this is totally untenable. IN could have stated they want a TW right from the starting. NLCA MK1 could still have been a TD program and ADA woukd have started working in a TE naval fighter right from early 2000s. Lets say, that was too early. Well, what was stopping IN to take TE req up in 2009..? I am sure even IAF would have been interested in it in 2009. Why suddenly the realisation about Single engine in 2015..? Any argument based on TE for safety is null and void in this context of discussion we are currently having. Yes, if one says, SE NLCA MK2 could not match NSQR, that I can understand as a logical argument from the IN's side.

Re, IN funding NLCA just to clarify, You see, the 40% component IN contributed was mainly for the STBF facility, if not all, which was clubbed with NLCA FSED1, ADA was program management agency for it. Without STBF, IN would have had to send MiG29K pilots abroad for training. It was a win-win for both sides. This is not to take away anything from IN on their initiative on NLCA and support in terms of Man, Money and material. Just to clarify. They have paid 25% or at least committed (not sure if they actually paid given they pulled out of MK2 around 2016-17, i am not sure on this) for LCA second mfg facility.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 11:19

For TEDBF my own proposal would be a non stealthy AMCA. Just use the space of Internal bays to accomodate larger MLG, more internal fuel (rearranment of LRUs would be needed for this). Larger wing for more lift. Rafale M is 650kg heavier than the C version. Lets give 1T for this fighter.

13T empty weight
6.5T internal fuel
6.5T external load
Clean TOW 21T
MTOW 26.5T

As I said previously, if MK2 with 17/10 can TO from skyjump, this fighter wuth 27/20 TWR should also be able to. And when we have a 110kN class engine we can go for full flegded 5G platform with internal bays.

Avionics can be fitted based on availability.

With AMCA based airframe we can basically jump to detailed design in a very short span. And then levarage a lot of work done for AMCA as copy paste, while concemtrating on Naval features alone for this one.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 11:53

Kartik wrote:
One thing I would like to ask those who talk about obsolescence- if it doesn't make sense to induct TEDBF into the IN the 2030s, how does it make sense to induct a Super Hornet or Rafale M into the IN in what will possibly be late 2020s? A few years difference will make one type (TEDBF) obsolete but not another (SH or Rafale M) that has been in service since a decade and a half already? What makes the Super Hornet and Rafale M operationally valid for the USN and French Navy and possibly IN, till 2050 and beyond? Why can't the TEDBF do that for the IN?


USN et al either already have a 5G fighter on the topline, or have easy import option available or have own programs on horizon. We dont. 4G platforms for them are bottomline. Not the same case for us. I'm not in favor of inducting Rafale or FA 18 in 2030s either. In addition, the french and Americans have incentives in keeping their MIC ticking and extracting maximum bang for the buck by keeping these fighters operational. We dont have any such peripheral benefits.

And just because the French outlined plans till 2070 doesn't mean it will remain relevent past 2070. Its a more like a marketing pitch. We upgraded MiG21 to Bisons significantly. It even shot down F16 just this year. Doesn't mean they are relevant in today's world.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Kakarat » 20 Nov 2019 12:29

More details on the TEDBF proposal
India’s DRDO To Ditch LCA Navy Mk2 For Cleansheet Twin-Engine Jet Design LIVEFIST

The top leadership of ADA told Livefist on Tuesday, “The Indian Navy is looking for a twin-engine deck based fighter in lieu of the LCA Navy Mk.2. With confidence generated from AMCA design, we have developed twin engine competence. Hence configuration is currently being worked out. This is being targeted as a replacement for the MiG-29K with a first flight by 2026.”

...
“We have all the elements required from both projects (LCA Navy and AMCA) to assemble the new design,” says the ADA leadership. “We are also equipped with knowledge of the pitfalls in the design and prototyping phase from past projects, so we have an adequate level of confidence. The bigger picture is that the next deck-based fighter of the Indian Navy should be an Indian design.”

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Prasad » 20 Nov 2019 12:32

Jays,
How feasible would it be to use the amca as a starting point but without an iwb? Also, twin canted better than single tail for rcs?

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Philip » 20 Nov 2019 12:53

The key point is the number of naval fighters anticipated for the entire costly exercise to be worthwhile.We will find it tough to operate 3 carriers and unless the new naval fighter can fit onto the existing lifts of the VikA and Vikrant to be used in the future, pointless! If it is designed so, then 3 carrier aircraft needs plus reserves would require around 100+ aircraft. That is the bare minimum for such a one-off fighter.Why the LCA MK-2 cannot be the basis for the naval bird astounds one as adding the 100 naval numbers, plus IAF needs, the numbers would cross 300. This would substantially bring down unit and support costs. Since the MIG-29K dimensions are well- known with us and their operational regimen too, designing the MK-2 LCA naval version within these dimensions should not be a difficult task since the LCA-N being used for trials fits the spatial parameters.

It beggars the Q whether these several programmes are a plot by the DRDO/ ADA to give them " developmental work" for another decade justifying budget allocations, latching onto the " make in India" mantra ?

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 12:55

Prasad wrote:Jays,
How feasible would it be to use the amca as a starting point but without an iwb? Also, twin canted better than single tail for rcs?

See my post above about AMCA based design.

Twin twil is better for a TE fighter for many reasons, especially a naval fighter. Overall height reduces for one engine out req. So no folding needed for under the deck storage. Canting would reduce height further. If designed accordingly they could shield engine exhaust to some extent for side aspect low IR signature. RCS reduction is also there. Dual radders provide redundancy and added directional control authority. And so on. But they also have structural issues from aerodynamic instabilities from the wing causing structural failures. Nothing that cannot be dealt with though. But for Delta wings they may get into the bursting LE vortices and lose authority at high AoA, and could also adversely affect delta wing aero.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Cybaru » 20 Nov 2019 13:16

JayS, your modified pic of NLCA is already in defence decode youtube videos. Can you stick some logos on those?

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby srai » 20 Nov 2019 13:29

As an interim measure to preserve MiG-29K life, how about the IN inducting a sizable fleet (~24) of NLCA MK.1 as a LIFT to take up burdens of regular flight training w/ carrier landings? Pilots still get their flight hours while reducing the number of carrier landing stress on the MiG-29K airframe in times of peace.

Kartik wrote:
Philip wrote:I agree with Nachi that the most sensible option is to buy more 29Ks , upgraded in the next lot, for the moment and develop an AMCA-N for the future, as if a large CV eventually gets approved by another act of insanity, it will arrive around the same time as AMCA, someting post 2030.

the Indian Navy is talking about retiring MiG-29Ks that are only 10 years old, in another 10-15 years and you talk about buying more MiG-29Ks as the best option? Have all their troubles been sorted out to even think of rewarding MiG Corp with another order?

Is it not obvious to even you that something is really wrong with how the MiG-29K seems to be able to handle the stress of carrier landings when it is going to see a shorter service life than even the disappointing MiG-23MF? the K's were supposed to have a TTL of 6000 hours, but I doubt the IN will come close to utilizing all of that. The IN doesn't even seem to be looking at the possibility of service life extension for the MiG-29K, which is troubling to me and indicates the possibility of problems with the structure and the IN looking at the best way to replace it instead.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby nam » 20 Nov 2019 14:04

LCA-N MK2 should have been twin engine from day 1!

ADA has already designed a twin engine fighter in form of AMCA. Granted it is not flying yet.

They have the choice to modifying AMCA in to non-stealth version or updated LCA MK2- IN to twin engine. Probably easier to "downgrade" AMCA.

Also it is not just Mig29K that requires replacement. It will probably replace some of the older Su30 as well.

We cannot replace 260 Su30 costing 70M with 260 AMCA costing 120-150M. There will be a need for cheaper twin engine. So it is either Rafale or TE LCA.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Prasad » 20 Nov 2019 15:13

JayS wrote:
Prasad wrote:Jays,
How feasible would it be to use the amca as a starting point but without an iwb? Also, twin canted better than single tail for rcs?

See my post above about AMCA based design.

Twin twil is better for a TE fighter for many reasons, especially a naval fighter. Overall height reduces for one engine out req. So no folding needed for under the deck storage. Canting would reduce height further. If designed accordingly they could shield engine exhaust to some extent for side aspect low IR signature. RCS reduction is also there. Dual radders provide redundancy and added directional control authority. And so on. But they also have structural issues from aerodynamic instabilities from the wing causing structural failures. Nothing that cannot be dealt with though. But for Delta wings they may get into the bursting LE vortices and lose authority at high AoA, and could also adversely affect delta wing aero.

Saw. More internal fuel = convert the iwb into additional regular fuel tanks without an openable bay is what you mean? And use the wings only for armaments. Question then will be, will it have enough TWR to takeoff from a stobar carrier at mtow?

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby chetak » 20 Nov 2019 15:14

twitter

Sources confirm that #Naval #LCA trials will be conducted on the #Vikramaditya before Dec 31 this year. @DRDO_India @indiannavy

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 15:39

Prasad wrote:
JayS wrote:See my post above about AMCA based design.

Twin twil is better for a TE fighter for many reasons, especially a naval fighter. Overall height reduces for one engine out req. So no folding needed for under the deck storage. Canting would reduce height further. If designed accordingly they could shield engine exhaust to some extent for side aspect low IR signature. RCS reduction is also there. Dual radders provide redundancy and added directional control authority. And so on. But they also have structural issues from aerodynamic instabilities from the wing causing structural failures. Nothing that cannot be dealt with though. But for Delta wings they may get into the bursting LE vortices and lose authority at high AoA, and could also adversely affect delta wing aero.

Saw. More internal fuel = convert the iwb into additional regular fuel tanks without an openable bay is what you mean? And use the wings only for armaments. Question then will be, will it have enough TWR to takeoff from a stobar carrier at mtow?


yes on that internal fuel thing. Basically eliminate the bays and all associated equipment altogether. AMCA already has 6.5T internal fuel which is a good number or we can trade off external max storage capacity with higher internal fuel to keep MTOW capped. So the designers can decide on the increase based on MTOW possible from ski jump. Besides a part of internal space will go in accommodating larger MLG. But at the same time, the internal payload of ~1.5T will be eliminated from the clean TOW. External payload of 6-6.5T is more than sufficient IMO. So 12T empty weight of current AMCA + 1T for navalisation + 6.5T internal fuel + 6T external load = 25.5T.

MiG29K has MTOW TWR of 18T/24.5T = 0.73 as per wiki specs. AMCA MK1 is supposed to have 20T/25T = 0.8. Naval version of AMCA Mk1 as proposed above would have no lesser than 20/26 = 0.77. Purely from TWR aspect, it doesn't seems to be having a big issue. However, note that we are talking in very lose terms here. So take it all with pinch of salt.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Karan M » 20 Nov 2019 15:44

JayS wrote:Someone needs to tell me what exactly is the technical issue with NAMCA that it cannot be done in 15yr timeline, but a fresh TEDBE is doable.

Let me say this categorically, if ADA did not design AMCA with a Naval vereion in mind, I am disppointed with them. What did they learn from LCA - NLCA saga if they could not design AMCA from outset for navalisation..? And before anyone says, that would have been suboptimal design for the IAF which they would have rejected, let me point out that ADA can always design AMCA in a modular approach that F35 took for Naval version with cousin parts and modular inserts for larger wing. AMCA is suposed to have more power with lower MTOW than F35. I just dont see why NAMCA could not TO from ski jump with TWR of 26/20 or even 27/20 (assuming F414 engine) when NLCA MK2 was supposed to TO with 17/10 TWR...? In the Air, Naval versions are almost always more restricted in terms of manoeuvreability compared to their AF counterparts. This is true for Rafale M as well.

Lets say, Navalised AMCA was still inadequate, if Navy is OK with a 4.5G fighter they should have no issue with a stripped down AMCA naval with relaxed stealth and suoercruise requirements. So what exactly ADA thinks it cannot do and they will need a 4.5G fighter compulsorily..?


I am glad they didn't, ADA is perfectly right in this case. The JSF is a perfect example of what not to do! Let me explain. The Navy and Marine requirements imposed a cap on the JSF length and weight, imposing an aero penalty for the aero performance and internal packaging. Many of the constant issues which pop up regarding heat, system failures, over complexity can be traced to that. The AF requirements for a F-16 drop in/replacement meant the JSF ended up being a single, not a dual engine design which any Navy would have likely wanted. The Marine requirement of a VTOL added further design issues to the overall dimensions for the JSF. At every stage, you have additional items added, developing the worlds most powerful single engine, which then melts the top of your carriers and you need specialized heat coating etc.

The best way to do things is what ADA is doing. Make custom designs for each service with common subsystems and design elements - e,g, AMCA like shaping, radar, IRST, EW, engine etc, like you said but not get locked down or be forced into design compromises because one service needs X and other needs Y and you are forced to compromise on A,B,C to fit in X and Y.

So if the Navy says, hey, we need payload/range but not breathtaking aero performance/ super cruise, and we prize frontal stealth over wideband/all -aspect RCS, so ADA can focus on putting in more fuel, focus on frontal RCS reduction, focus more on reliability etc and manage accordingly.

The focus on hard deck landings will also mean more structural strength, ensuring avionics are also ruggedized. The Su-30 in its Brahmos variant gained heavy weight over the standard Su-30, so the IAF chose to modify only 40. Similarly, the 29K will not be as sprightly a performer as the AF 29's. So, why burden the baseline AMCA design with all sorts of structural mods or requirements for the same, for a Navy variant? Similarly, all alloys etc will have to be evaluated from a naval corrosion perspective.

Best to have 2 different designs and move accordingly.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Karan M » 20 Nov 2019 15:52

Folks point to Rafale M and Rafale as a counterpoint. The issue here is of experience and optimization. The French had experience with the Etendard and decades of Mirage variant experience before the Rafale, and are experts in MDO (multi-disciplinary optimization) plus an ecosystem which makes them everything from engines to avionics in France. We lack both as we are still setting up the capabilities in India. Most of our systems are via the LCA program itself, on a shoe-string budget. For us then to squeeze out every ounce of performance from a single design, and make it a one-stop shop is very hard. The Americans are discovering it (again) the hard way too, despite literally working with a blank cheque book.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby JayS » 20 Nov 2019 16:28

Karan M wrote:
JayS wrote:Someone needs to tell me what exactly is the technical issue with NAMCA that it cannot be done in 15yr timeline, but a fresh TEDBE is doable.

Let me say this categorically, if ADA did not design AMCA with a Naval vereion in mind, I am disppointed with them. What did they learn from LCA - NLCA saga if they could not design AMCA from outset for navalisation..? And before anyone says, that would have been suboptimal design for the IAF which they would have rejected, let me point out that ADA can always design AMCA in a modular approach that F35 took for Naval version with cousin parts and modular inserts for larger wing. AMCA is suposed to have more power with lower MTOW than F35. I just dont see why NAMCA could not TO from ski jump with TWR of 26/20 or even 27/20 (assuming F414 engine) when NLCA MK2 was supposed to TO with 17/10 TWR...? In the Air, Naval versions are almost always more restricted in terms of manoeuvreability compared to their AF counterparts. This is true for Rafale M as well.

Lets say, Navalised AMCA was still inadequate, if Navy is OK with a 4.5G fighter they should have no issue with a stripped down AMCA naval with relaxed stealth and suoercruise requirements. So what exactly ADA thinks it cannot do and they will need a 4.5G fighter compulsorily..?


I am glad they didn't, ADA is perfectly right in this case. The JSF is a perfect example of what not to do! Let me explain. The Navy and Marine requirements imposed a cap on the JSF length and weight, imposing an aero penalty for the aero performance and internal packaging. Many of the constant issues which pop up regarding heat, system failures, over complexity can be traced to that. The AF requirements for a F-16 drop in/replacement meant the JSF ended up being a single, not a dual engine design which any Navy would have likely wanted. The Marine requirement of a VTOL added further design issues to the overall dimensions for the JSF. At every stage, you have additional items added, developing the worlds most powerful single engine, which then melts the top of your carriers and you need specialized heat coating etc.

The best way to do things is what ADA is doing. Make custom designs for each service with common subsystems and design elements - e,g, AMCA like shaping, radar, IRST, EW, engine etc, like you said but not get locked down or be forced into design compromises because one service needs X and other needs Y and you are forced to compromise on A,B,C to fit in X and Y.

So if the Navy says, hey, we need payload/range but not breathtaking aero performance/ super cruise, and we prize frontal stealth over wideband/all -aspect RCS, so ADA can focus on putting in more fuel, focus on frontal RCS reduction, focus more on reliability etc and manage accordingly.

The focus on hard deck landings will also mean more structural strength, ensuring avionics are also ruggedized. The Su-30 in its Brahmos variant gained heavy weight over the standard Su-30, so the IAF chose to modify only 40. Similarly, the 29K will not be as sprightly a performer as the AF 29's. So, why burden the baseline AMCA design with all sorts of structural mods or requirements for the same, for a Navy variant? Similarly, all alloys etc will have to be evaluated from a naval corrosion perspective.

Best to have 2 different designs and move accordingly.


- We don't have marine requirements, which is the most restrictive of all. So lets drop it.
- Hard to believe Naval version would have restricted length and weight when they wanted a twin-engine jet which would have been invariably longer and heavier. I have not come across any reference stating so. If you have please share.
- F35 has a decent length for a single-engine jet. The longer length would have increase empty weight, screwing the performance for a given engine for AF version too. I don't understand why would the USAF want a longer version unnecessarily. And if the requirement was so overwhelming, I am sure LM could have found a way to add fuselage plugs in the common design for AF alone, given AF requirement and export potential for it is the largest.
- If you ask me, its the Navy who has done compromises not the other way round. Diamond wing is not the best solution for Approach/landing aero. While Rafale could manage with the exact same wing-canard combo for both the application (actually Rafale's exceptional ability of MTOW being 2.5x of its empty weight is the result of its design for very slow landing/approach speed for deck landing) (and similarly, F/A18, Su33, MiG29K have LREX to help in approach/landing), F35 needed a slightly different solution. LM sorted out the issue by having a larger wing created using inserts of larger size in the common wing structure. From what I know there are no severe restrictions on F35's landing weight. So this solution works.
- the strengthening of structural components for naval application is done through simply using a concept called Cousin parts - you thicken the AF version parts or replace Aluminum with Titanium for additional strength. This has greatly reduced time and effort in design and development. This does not burdon the AF variant any more than a separate design would have. AF version stays lean. Even in case of Rafale, the commonality in aerostructure is 80% IIRC. Did Rafale M burdened Rafale C's performance..? It did not. The Rafale M weighs 650kg more and is less maneuverable. But the AF version has no restriction. In fact, it has better payload and range capabilities on account of better aerodynamic capability from the M version. This while maintaining 80% structural commonality and 95% system level commonality. Arguably, Rafale like solution was not feasible for 5G given design implications due to stealth requirement, but there is no particular reason why F35C's approach could not have worked.
- AMCA is already twin-engine and having the engines which Navy would anyway use.
- Of course there is always a cost for commonality, but then there is a cost for separate development programs as well. GIven Navy's smaller requirement, I feel cost of commonality is lower than cost of fresh new design. We are not going to import any of these jets. IAF might be interested in de-navalised version. But if they get 114 MMRCA 2.0 and later AMCA at hand, I wonder how much they might want, when it doesn't offer much unique capability and neither it is cheaper given small number. Wouldn't they simply buy more AMCA..??

I have spent considerable time on this matter. I think we could have made AMCA in such a way that it could have easily (relatively speaking) been navalised when need arises. And I dont mean exact same fighters for both applications, making AMCA design in such a way that parts needing modifications for Navalisation would be drop-in fit post-modification, without having to change rest of the structure too much or at all. For example, placing MLG attachment points such a way that they will not need change for Naval version. And this is not a big thing really to expect. AMCA being twin engine, already makes things easy.

I think you misunderstood me. I dont want exact same fighters for IAF and IN. Neither F35A and F35C are exactly the same. The commonality is less than one would expect.

I dont want to justify or oppose the decision anymore. I just want to understand it. I will make my arguments only to invite counter arguments which might help me understand the situation better.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby brar_w » 20 Nov 2019 18:49


Indranil
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Indranil » 20 Nov 2019 19:58

I think this is the case of everybody finally biting the bullet.
1. For ADA, NLCA Mk2 powered by a 414 would always be energy strapped for STOBAR operations.
2. For Navy, naval AMCA would be expensive and time consuming. We would have developed TEDBF ground up by now, if we did not start from LCA. As they say, hindsight is 2020.

Rest, whatever is obvious to us is obvious to ADA and Navy as well. They will not design the aircraft from scratch. They will reuse everything they can from AMCA and NLCA Mk2.

I have a feeling. We are going to see an enlarged MWF with two engines as TEDBF. Aka Rafale++. And soon IAF will show interest and an AF version will be derived out of it as well.

Current plan is first flight of MWF in 2021/22, AMCA in 2025/26, and the TEDBF in 2026/27. Exciting times ahead! Eagerly looking forward to AI 2021 now.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby ramana » 20 Nov 2019 20:58

Karan M wrote:Folks point to Rafale M and Rafale as a counterpoint. The issue here is of experience and optimization. The French had experience with the Etendard and decades of Mirage variant experience before the Rafale, and are experts in MDO (multi-disciplinary optimization) plus an ecosystem which makes them everything from engines to avionics in France. We lack both as we are still setting up the capabilities in India. Most of our systems are via the LCA program itself, on a shoe-string budget. For us then to squeeze out every ounce of performance from a single design, and make it a one-stop shop is very hard. The Americans are discovering it (again) the hard way too, despite literally working with a blank cheque book.


Very insightful. The Etendard->M2K lineage is well understood in the higher planners.
In fact this very example was mentioned.

Naval LCA Mk1 is India's Etendard and will lead to other planes.
Spiral development is the optimum way.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby disha » 20 Nov 2019 22:28

Indranil wrote:... They will reuse everything they can from AMCA and NLCA Mk2.

I have a feeling. We are going to see an enlarged MWF with two engines as TEDBF. Aka Rafale++. And soon IAF will show interest and an AF version will be derived out of it as well.


If TBDEF is the core twin-engine structure for 4.5 gen aircraft and a stepping stone for AMCA, then it makes some sense.

(legend: {} => future; <> => proposed; () => cancelled)

So from Navy's perspective: NLCA-Mk1 -> (NLCA Mk2) -> <TBDEF> -> {NAMCA}
And from AF's perspective : LCA-Mk1 -> Mk1A -> Mk2/MWF -> <TBDEF-AF> -> AMCA

Here, in my thought process - TBDEF-AF is a stripped-down prototype AMCA.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Indranil » 20 Nov 2019 23:46

1. AMCA design is much more mature than to be stripped down version of anything now.
2. They must have determined that adapting that design to a naval application with 2X98 kN engine will be troublesome.
3. So they will develop a new airframe, that will fulfill the STOBAR requirements. They want aerodynamic performance and hence the step away from naval AMCA. All the innards and sensors will be from AMCA.

Actually there is a lot of cross pollination of ideas between MWF and AMCA right now. Expect MWF to be top of class in the 4th generation light/medium
category.

I can see IAF's force structure beyond 2040. Light-MWF, TELBF (optimized from TEDBF) with same engine, weapons, avionics, radar etc. etc. Imagine the simplification of the logistic chain!!!

AMCA-Mk2 will be the tip of the sphere.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby ramana » 20 Nov 2019 23:47

Folks try to at-least browse
Fundamentals of Aircraft and Airship Design Volume I by Leland Nicolai.

Its a very practical book and published by AIAA.

It describes aircraft design from DC-3 to F-35B.
From Art of design to Science of Design.

Should be available on download sites.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Karan M » 21 Nov 2019 00:26

JayS wrote:- We don't have marine requirements, which is the most restrictive of all. So lets drop it.


Corrosion requirements and hard landing issues would remain, for jump jets.

- Hard to believe Naval version would have restricted length and weight when they wanted a twin-engine jet which would have been invariably longer and heavier. I have not come across any reference stating so. If you have please share.


A lot of these links are no longer available, I'll need to look under my own posts. But the basic issue were a whole lot of changes around wing size, requirements, around dimensions for a Naval jet (it had to be sized to fit Naval hangars and elevators, and decks) which were far more restrictive than those for a CTOL AF fighter. The CV wing had changes to its design for low-speed approaches etc. Again, this has had issues elsewhere or contributed to it.
https://breakingdefense.com/2013/08/don ... sue-fixed/

What happened? Basically, new algorithmns were written, tested in the trans-sonic envelope where most of the problems occurred and the services found a solution that didn’t completely eliminate all drop at all times but left the plane performing to the highest standards achievable. In short, they found a problem and fixed it to a standard all three services could live with.


Brilliant PR speak and how we really need to learn from the US MIC in how they "message" their problems away. In short, it remains, and a concession has been given. Note how we belly-ached about the LCA in comparison.

https://www.vanityfair.com/news/2013/09 ... eed-martin

To turn its X-35 prototype into a fleet of F-35 fighters, Lockheed has relied on two seemingly separate but equally controversial acquisition practices. In military jargon, these are known as “commonality” and “concurrency.”

Commonality simply meant that the three F-35 variants would share portions of high-cost components like the airframe, the avionics, and the engines. This was supposed to help ensure that the plane was “affordable”—a term that the company and Defense Department managers invoked with the frequency of a Vajrayana chant. But commonality did not really come to pass. The original plan was that about 70 percent of all the parts on the airplanes would be common; the actual figure today is about 25 percent. Commonality, even at this reduced level, has unintended consequences. When a crack in a low-pressure turbine blade was discovered in an air-force F-35A engine earlier this year, Pentagon officials took the only responsible course, given that the part is used in all models: they grounded the entire fleet of F-35s, not just the ones flown by the air force. In his June testimony, the Pentagon’s Dr. Gilmore revealed another, less public grounding of the entire F-35 test fleet, which occurred in March 2013 after the discovery of “excessive wear on the rudder hinge attachments.”

From the outset, Lockheed assured Pentagon officials that technological innovation, including heavy reliance on computer simulation, which could take the place of real-world testing, would keep costs down. The Pentagon bought those assurances and allowed the company to design, test, and produce the F-35 all at the same time, instead of insisting that Lockheed identify and fix defects before firing up its production line. Building an airplane while it is still being designed and tested is referred to as concurrency. In effect, concurrency creates an expensive and frustrating non-decision loop: build a plane, fly a plane, find a flaw, design a fix, retrofit the plane, rinse, repeat.

Vice Admiral David Venlet, who managed the J.S.F. program until late last year, acknowledged the absurdity in an interview with AOL Defense: “You’d like to take the keys to your shiny new jet and give it to the fleet with all the capability and all the service life they want. What we’re doing is, we’re taking the keys to the shiny new jet, giving it to the fleet, and saying, ‘Give me that jet back in the first year. I’ve got to go take it up to this depot for a couple of months and tear into it and put in some structural mods, because if I don’t, we’re not going to be able to fly it more than a couple, three, four, five years.’ That’s what concurrency is doing to us.”


Re: Naval use LM had to change its entire RAS approach and that too needed time consuming testing. Again, trying a "common approach" for all problems.

Having built the F-117A Nighthawk and F-22 Raptor, Lockheed Martin has plenty of experience with the highly toxic coatings and svelte surfaces that help stealth aircraft go undetected. The company also knows that the technology is finicky and has the capacity to turn a cutting-edge fighter into a hangar queen. A significant portion of an F-22 Raptor’s downtime is spent in hangars with maintainers mending its stealthy coating, which has a tendency to wear off during certain meteorological conditions.

When the time came to cover the F-35 with a radar-absorbing material, Lockheed changed its technology, covering the plane with a rigid coating applied in sections. Unfortunately, prolonged use of the plane’s afterburners causes the F-35’s stealthy outer layer—as well as the skin underneath—to peel and bubble near the tail. As a result, the F-35 is prohibited from supersonic flight while Lockheed Martin comes up with a fix—one that will require retrofitting the 78 planes that have already come off the production line. The fact that this could have occurred at all, much less on the Pentagon’s biggest and most important weapons program, baffles Pierre Sprey. “Everyone knows that the faster a plane goes, the warmer the skin gets,” he says. “All they had to do was test a one-square-foot portion in an oven. Yet again, we’re finding this stuff out on planes that are already built.”

When asked how two signature elements of the same program—stealth and supersonic speed—could have come into such direct collision, a senior Pentagon official with access to F-35 test data explained, “This is not rocket science. When you let a contractor do whatever he wants to do, and you don’t watch him very carefully, he’s going to trust his engineering analysis as opposed to doing what you just said—building a piece and putting it in an oven. Because he looks at a piece of paper and he’s got his engineers and he says, ‘Oh, this is good; we’ve got margin there. We’ve got an extra 10 degrees and an extra five minutes on the coatings. We’re good. We don’t have to test that.’ Government oversight would say, ‘Show me.’”


This is the guy who ran the program itself

A more disturbing assessment came from perhaps the most improbable source: Christopher Bogdan, the general who heads the Joint Strike Fighter program. A few weeks after I saw him in Norway, we sat down at his office in Crystal City. The plate-glass windows offered views of the Jefferson Memorial and the Washington Monument, and if Bogdan had been wearing a dress uniform with his ribbons and his three stars, the scene would have looked like a cartoon or a cliché. But Bogdan, 52, wore a green flight suit. He too is a pilot, one who has logged 3,200 hours in 35 different military aircraft. When answering questions, he frequently thumped his fist on a conference table.

With dry understatement he took issue with the bedrock concept of the Joint Strike Fighter—that a single airplane could fulfill the different missions of three different services—calling it “a little optimistic.”


This is from Defense News in June 2019 about continuing problems:
https://www.defensenews.com/air/2019/06 ... -problems/

Context - she is the author who did this NYT piece in August (basically not their usual crappy journos, so quotable)
https://www.nytimes.com/2019/08/21/maga ... ogram.html

There soon turned out to be an essential flaw in the grand plan for a single plane that could do everything. Design specifications demanded by one branch of the military would adversely impact the F-35’s performance in another area. “It turns out when you combine the requirements of the three services, what you end up with is the F-35, which is an aircraft that is in many ways suboptimal for what each of the services really want,” said Todd Harrison, an aerospace expert with the Center for Strategic and International Studies. “It is much more expensive than originally envisioned, and the three versions of the plane actually don’t have that much in common.”

But early in the program, Lockheed Martin began construction with glowing optimism. The company decided to build the Air Force’s F-35A first because it was considered the simplest model, then move on to the difficulties of the F-35B short-takeoff and vertical-landing version and then the F-35C, which can land on an aircraft carrier — a decision that turned out to be a mistake. Once Lockheed’s engineers proceeded with the more demanding design of the F-35B, they found that their initial weight estimates were no longer accurate and the B model was on track to be 3,000 pounds too heavy to meet specifications. The company was forced to begin an extensive redesign project that added an 18-month delay to the program.



- F35 has a decent length for a single-engine jet. The longer length would have increase empty weight, screwing the performance for a given engine for AF version too. I don't understand why would the USAF want a longer version unnecessarily. And if the requirement was so overwhelming, I am sure LM could have found a way to add fuselage plugs in the common design for AF alone, given AF requirement and export potential for it is the largest.


They weren't looking at just longer lengths but overall dimensions. LM was also having to manage cost impact for the fighter. They were under severe pressure to manage the overall cost/airframe and cost/program so obviously, it was in their best interest to reduce significant redesign/platform. However, as testing progressed those very limitations have come back to bite them as system complexity has increased.

In an article that Bloomberg News publishes on August 31, 2007, it is announced that Lockheed Martin is exceeding the budget on the first phase of the Joint Strike Fighter program. The manufacturer warns that the reserves will be spent by the end of 2008, unless cuts are made. Lockheed Martin is seeking US Defense Department approval to lessen the number of test aircraft and personal plus hundreds of test flights to save money, and replenish a reserve fund.


Or this:
https://breakingdefense.com/2011/12/jsf ... st-slow-v/

- If you ask me, its the Navy who has done compromises not the other way round. Diamond wing is not the best solution for Approach/landing aero. While Rafale could manage with the exact same wing-canard combo for both the application (actually Rafale's exceptional ability of MTOW being 2.5x of its empty weight is the result of its design for very slow landing/approach speed for deck landing) (and similarly, F/A18, Su33, MiG29K have LREX to help in approach/landing), F35 needed a slightly different solution. LM sorted out the issue by having a larger wing created using inserts of larger size in the common wing structure. From what I know there are no severe restrictions on F35's landing weight. So this solution works.


That's the whole point, all 3 services are having to make compromises and these compromises are sub-optimal. As it is, fighter design is all about trade-offs, so why would you wish to add service specific trade-offs on top of it? This has the same issue we saw with the LCA, i.e. limiting it to MiG-21/LWF dimensions then adding more and more MR requirements derived from larger aircraft. What I mean is one compromise at one point ends up causing a lot of issues elsewhere.

LM keeps bragging about how great their packaging is, their critics pointed out they were making a virtue out of a (necessary) vice given there literally was no space to manage conventional answers given the contradictory requirements of stealth/heat management & volume taken up by an internal weapons bay.

Why go this path at all? Whether this issue or the concurrency, both were flawed decisions from the get-go.

- the strengthening of structural components for naval application is done through simply using a concept called Cousin parts - you thicken the AF version parts or replace Aluminum with Titanium for additional strength. This has greatly reduced time and effort in design and development. This does not burdon the AF variant any more than a separate design would have. AF version stays lean. Even in case of Rafale, the commonality in aerostructure is 80% IIRC. Did Rafale M burdened Rafale C's performance..? It did not. The Rafale M weighs 650kg more and is less maneuverable. But the AF version has no restriction. In fact, it has better payload and range capabilities on account of better aerodynamic capability from the M version. This while maintaining 80% structural commonality and 95% system level commonality. Arguably, Rafale like solution was not feasible for 5G given design implications due to stealth requirement, but there is no particular reason why F35C's approach could not have worked.


I am not sure the cousin parts approach is the only issue here. Its not merely the structural parts, its also the avionics, the actuators, the hyrdaulics, all the associated subsystems which all need to be tested and re-qual'ed for the Naval environment. The alloys will need to be tailored, the coatings, paint, everything ends up with an additional test margin, cost impact, timeline impact. In the JSF for instance:

Fatigue testing has barely begun, Venlet said. The CTOL variant’s fatigue testing is about 20 percent complete; the CV variant has not started yet. For the STOVL variant, fatigue testing was halted at 6 percent last year and has not resumed after a crack in a large bulkhead in the wing was found, requiring a major redesign of that part.


- AMCA is already twin-engine and having the engines which Navy would anyway use.


Yes, use the AMCA as a baseline but then ditch or change what the Navy doesn't need or want.

- Of course there is always a cost for commonality, but then there is a cost for separate development programs as well. GIven Navy's smaller requirement, I feel cost of commonality is lower than cost of fresh new design. We are not going to import any of these jets. IAF might be interested in de-navalised version. But if they get 114 MMRCA 2.0 and later AMCA at hand, I wonder how much they might want, when it doesn't offer much unique capability and neither it is cheaper given small number. Wouldn't they simply buy more AMCA..??


TBH, when I look at cost, its a no-brainer that it works out for us, despite any additional costs (I did some rough calculations on how much we provide to Indian industry). The main "costs" I perceive in our context "user acceptance" and "timeline". These are two of the main challenges I see we grapple with in our local context. If for whatever reason our answer is 80% as versus 90%, it attracts horrible criticism from the services, massive leaks calling it junk, and if it is delayed, the oush for an import begins. These are invariably due to too many complex requirements expected out of contradictory specifications and inexperienced team/limited local support, add budgetary woes. This is the main reason I'd prefer a design optimized and run by each service which *they* own and can manage to their needs as versus grimacing that the IAF is getting x specification which will affect Navy's Y requirement or the IAF grimacing that to keep design "straightforward" some compromises were made to their awesome air superiority jet which can no longer accelerate as fast as the latest PAK-FA offered by the Russians etc.

I have spent considerable time on this matter. I think we could have made AMCA in such a way that it could have easily (relatively speaking) been navalised when need arises. And I dont mean exact same fighters for both applications, making AMCA design in such a way that parts needing modifications for Navalisation would be drop-in fit post-modification, without having to change rest of the structure too much or at all. For example, placing MLG attachment points such a way that they will not need change for Naval version. And this is not a big thing really to expect. AMCA being twin engine, already makes things easy.

I think you misunderstood me. I dont want exact same fighters for IAF and IN. Neither F35A and F35C are exactly the same. The commonality is less than one would expect.

I dont want to justify or oppose the decision anymore. I just want to understand it. I will make my arguments only to invite counter arguments which might help me understand the situation better.


Fair enough, I have a very simple approach to this whole thing. Just look at our limitations and context. I do know that w/o Parrikar sir's intervention the NLCA was a no-go. The Navy literally pulled the plug on the program. Given that, I won't be surprised if IAF was the "only game in town" for AMCA and they went with the one customer they had, as versus trying to delay things waiting for Naval approval and adding to possible delay by trying to incorporate Naval needs. The initial AMCA work was done out of DRDO's own seed money, as the GOI didn't release formal funds till later.

I also don't think the AMCA naval modification would be straightforward, because several of the sources i did read on the JSF made it clear that the LM guys were pushing back on the platform specific changes because of budget issues. I'd rather we had separate programs budgeted separately! Look at the number of unique parts and cousin parts here - why even bother with this approach, as versus clean-sheet optimization.

Image

In our case, the Navy may say, the TEDBF has to be within the following dimensions based on our ship envisaged capabilities, fit the following elevator with folding wings, have this level of stealth (because with corrosion can't manage more than that), we are stressing on range/payload, reliability, we need low speed handling able to manage the carrier deck, quick stop etc.

IAF may say - relax these and focus on kinematics for BVR, focus on broadband stealth - we are up against IADS, we need avionics completely integrated with AWACS and IACCS..

I mean why compromise one set of requirements to manage the other. Our programs are dirt cheap compared to worldwide ones. We don't face their budgetary issues with program costs, but we start from a lower baseline of experience, subsystem availability and managing optimization. In which case we are better off de-risking our programs by making them simpler and tailored for each service in particular, rather than adding complexity by making them capable of anything.

Take RAS for instance, suppose we have a system capable of IAF use but not Naval use, and which needs a certain manufacturing process which AF is willing to invest in. By keeping programs separate and costed separately, you can go ahead with the IAF one & stop worrying about making a single answer suitable for both AF and Navy.

See this for instance, from 1997 about the B-2 - just pointing this out for instance, about the kind of issues faced when dealing
WASHINGTON -- Two years ago ('95), the problem with the Air Force's B-2 Stealth bombers, which cost $2 billion apiece, was that their radar could not tell a rain cloud from a mountainside.Now the problem is that the B-2 cannot go out in the rain.
The investigative arm of Congress reported this week that the B-2, the world's most expensive aircraft, deteriorates in rain, heat and humidity. It "must be sheltered or exposed only to the most benign environments -- low humidity, no precipitation, moderate temperatures," said the report by the General Accounting Office.


Now, a decade later, from 2009
http://www.washingtonpost.com/wp-dyn/co ... 03020.html
The aircraft's radar-absorbing metallic skin is the principal cause of its maintenance troubles, with unexpected shortcomings -- such as vulnerability to rain and other abrasion -- challenging Air Force and contractor technicians since the mid-1990s, according to Pentagon officials, internal documents and a former engineer.


Point being, you may need to change things entirely for an AF approach to a problem versus a Naval one. Your AMCA are going to be most of the time in hangars or on AFB, shielded from the elements, whereas the Naval TEDBF may be exposed on the deck.

So AMCA may be able to get by with stealth & RAS, and limited EW but Naval fighter may take an entirely different approach and focus more on payload including EW to fight its opponent.

Similarly, IN is very pragmatic about using imported subsystems. If program costs shoot up, and they need specialized gear, for a low production run in TEDBF you can always import. Indigenize over AMCA..

Just pointing out there are dozens of small decision points which can add up over time.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Picklu » 21 Nov 2019 00:52

In recent history, there has been 3 path for common AF and N version

a. Restrict everything in the middle F111 : neither here nor there design full of compromise and the success of the design is visible
b. Take AF and convert to N : Mig29K anyone?
c. Take N and convert to AF: Shornet but despite the hype USAF do not operate it, nither does any of it's serious clients like Israel, Japan, SoKo etc. Only a few basket case Canada etc who don't really have a threat to justify an AF but are bound by treaty obligations and hence happy with 2nd hand dirt cheap extra safe (due to twin engine)

JSF doesn't really count, the two versions of the plane are as good as two completely different plane and costed twice as much to develop. As good as IA multi caliber assault rifle.

French did go for Rafale but from all gossip, Typhoon does much better on pure A2A basis. IAF MMRCA win was because "omnirole" and L1

A Naval fighter, due to extra strengthening, marinisation and position of landing gear plus hook, are seriously compromised in terms of fuel fraction, agility, max take home payload, max payload size etc. No AF worth its name would induct a version of a naval fighter. It would be as good as taking a AF fighter and convert it for naval operation.

So, anyone hoping for a AF version of TEDBF is being overtly optimistic, I do not see that happening unless AMCA program gets significantly delayed and this becomes a fall back.

Cain Marko
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Cain Marko » 21 Nov 2019 00:59

IMVHO.... This is a golden opportunity. TBDF and Lca mk2 should be combined into one requirement called the MRCA + NMRCA. This should be a stepping stone to the AMCA and at rafale levels.

Basically a twin engined LCA at around
10 tons empty
m88+kaveri engines pumping out 85kn thrust or as a safe bet he f404in56s.
9-11 hps,
7+ ton payload,
irst
Internal ew, maws etc
Aesa radar

This should be a mirage 2000 to 4000/rafale jump. No more.

IAF should order another 125 LCA mk1A at least to recover the investments made in the bird, which should then be aggressively exported to other countries.

MRCA should be totally cancelled. Perhaps a g2g purchase of rafales and fulcrums at most on urgent basis to buy time. No imports should ever be purchased again.
Last edited by Cain Marko on 21 Nov 2019 01:03, edited 1 time in total.

Picklu
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Picklu » 21 Nov 2019 01:01

I think the name TEDBF is as good a name as Lampyridae from MBB and serves a similar purpose of cough, cough ... messaging (to Ruskies in this case, be reasonable on price of next 2 sq of mig29k or else)

Mig29k is a pig no doubt but the prettiest pig with lipstick compared to the other options i.e. harrier and nlca. The rest needs catapult and hence do not count.

If the plan succeeds, 2 sq of 29K would be around 1.5 B, the cheapest outgo that we as a nation can afford.

For folks lamenting on capabilities part, let's be honest. Our naval carrier fleet has never been anything more than a token force. It was nowhere close to implement a sea control strategy. Better to keep it in the same level optimizing resources and implement a better sea denial posture with more SSN and SSK is far more desirable. Saving development resources here is going to help in all these more strategic areas as in SSN, SSK, Turbofan etc.

Heck, I would say in case we have more aircraft design and development resource available, better to use the same to develop a gultstream or EMB class aircraft that can act as a base for mpa, AEW, tanker, Cargo, Utility as well as passenger in desi market

Picklu
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Picklu » 21 Nov 2019 01:10

If we have earmarked another 1 billion for TEDBF development, I would suggest please spend the same amount to fix and certify the current low powered Kaveri and then create a sq of LCA sport trainer version with that Kaveri.

That single operational squadron would generate so much knowledge that it would be much more valuable than 57 TEDBF put together.

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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Indranil » 21 Nov 2019 01:17

Picklu sir,

I am sorry your information is very flawed.

1. Superhornets are the main stay of every naval and airforce that operates it.
2. TEDBF will not be a super hornet. The former has to take off with full MTOW from a STOBAR which the latter can't. So, the former will be more like a Mig29k powered by superhornet's engines.
3. There is only one situation where the Rafale is not as good as the EF in A2A. High altitude (>45,000) feet and high speed. No Rafale pilot will enter a fight in the horizontal plane at that altitude with an EF. Similarly, an EF pilot won't climb down unless he has to. In short, there are no generic ground rules for A2A. It depends on the aircrafts involved. A Rafale WILL lose to an AJT, if it enters a slow turning fight at low altitudes. The EF will do worse. If a F18 and F16 were fighting in a vertical plane, the F18 has an advantage at one point of the loop, and the F16 in the other. These are 101 to all pilots. They will smile at you if you just make blanket statements like Rafale is better than EF or vice versa!!!

Picklu
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Picklu » 21 Nov 2019 01:27

Indranil wrote:Pickle sir,

I am sorry your information is very flawed.

1. Superhornets are the main stay of every naval and airforce that operates it.
2. TEDBF will not be a super hornet. The former has to take off with full MTOW from a STOBAR which the latter can't. So, the former will be more like a Mig29k powered by superhornet's engines.
3. There is only one situation where the Rafale is not as good as the EF in A2A. High altitude (>45,000) feet and high speed. No Rafale pilot will enter a fight in the horizontal plane at that altitude with an EF. Similarly, an EF pilot won't climb down unless he has to. In short, there are no generic ground rules for A2A. It depends on the aircrafts involved. A Rafale WILL lose to an AJT, if it enters a slow turning fight at low altitudes. The EF will do worse. If a F18 and F16 were fighting in a vertical plane, the F18 has an advantage at one point of the loop, and the F16 in the other. These are 101 to all pilots. They will smile at you if you just make blanket statements like Rafale is better than EF or vice versa!!!


No Sir for me please, Indranil.

Shornet are excellent Naval aircraft no doubt but please look into the airforces that operate it. Aus, Fin, Ca, Swiss, Spain, Malasia...... Their threat level and their other aircrafts. The answer would be obvious.
Last edited by Picklu on 21 Nov 2019 01:37, edited 1 time in total.

Karan M
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Karan M » 21 Nov 2019 01:37

Who gets the blame for a 20-year misadventure? In 2013, the GAO's Michael Sullivan asserted that Lockheed had failed to get an early start on systems engineering and had not understood the technologies involved at the program's launch. But a RAND study the same year found the three F-35 variants had drifted so far apart during development that having a single base design may prove to be more expensive than if services had just built separate aircraft tailored to their own requirements from the get-go. And to this the fact that enormous defense projects almost always go over-budget and you've got a recipe for the start-and-stop, muddled first two decades of the F-35.

https://www.popularmechanics.com/milita ... 57/wtf-35/

https://www.star-telegram.com/news/busi ... 39955.html

Lockheed Martin’s F-35 jet fighter, designed by the Pentagon to serve the Air Force, Navy and Marine Corps, is likely to end up costing more than building separate planes for each service would have, a Rand Corp. study has found.

“Under none of the plausible conditions we analyzed did” the F-35 “have a lower life-cycle cost estimate,” Rand, a nonprofit research institution, said in the report released this week.

The report questions a fundamental tenet of the Pentagon’s costliest weapons program — that building different versions on a common base will reduce costs. Rand analyzed an estimated $1.5 trillion “life-cycle cost” that includes acquisition plus long-term support.
....

While the initial goal for the F-35 was to have 80 percent of the airframe components in common for the three versions, Rand found that by 2008, that had dropped to 27 to 43 percent because of development difficulties and increasing weight.

“As of this writing, it is not clear how common the mission systems, avionics, software and engine will be among the three service variants,” said Rand, based in Santa Monica, Calif.

“The tension between maintaining maximum commonality and meeting different service requirements has been difficult to resolve,” Rand said. That has resulted “in less common variants, greater technical complexity and risk,” as well as difficulty in “achieving the promised savings.”

Picklu
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby Picklu » 21 Nov 2019 01:44

On one hand, we are cutting down our sniper rifle order to 1/3rd due to budget constraints.

On the other, we "want" to import 110 SEF, 57 N aircraft, another 2 squadron of Rafale, going to develop a TEDBF from scratch and oh, catapult for our next carrier. I forgot, the limeys want to sell a copycat of QE to us as well.

It would be funny if it was not so tragic!!!

ramana
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby ramana » 21 Nov 2019 02:15

So to sum up different planes for different services is the best approach or else you end-up with a compromise no one is happy with.

ramana
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Re: Naval Tejas Mk1/Mk2: News & Discussion - 23 February 2019

Postby ramana » 21 Nov 2019 02:17

Picklu wrote:On one hand, we are cutting down our sniper rifle order to 1/3rd due to budget constraints.

On the other, we "want" to import 110 SEF, 57 N aircraft, another 2 squadron of Rafale, going to develop a TEDBF from scratch and oh, catapult for our next carrier. I forgot, the limeys want to sell a copycat of QE to us as well.

It would be funny if it was not so tragic!!!


Not happening.
2 Squadron for Rafale, 57 N Aircraft will be Naval LCA, 110 SEF will be Tejas MkII balancing cost, capability and schedule.


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