LCA Tejas: News and Discussions

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fanne
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Re: LCA Tejas: News and Discussions

Post by fanne »

Either I am way smart or there is indeed more to the story- I had predicted in the forum that chobham will do exactly that.
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Re: LCA Tejas: News and Discussions

Post by Sid »

Can't we just replace the nose cone after FOC is complete, it's prototype can still be tested and installed separately? Its not like something which may require structural changes.

Regarding in flight refueling, i am not sure what's the rush for FOC. Doesn't LCA already have plumbing in place for it?
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Re: LCA Tejas: News and Discussions

Post by shaun »

^^^^ BVR missiles firing one of the key point for FOC and the present nose cone doesn't support 2032 to fire 77 at its full range.
some Jaguars have EL/M 2032 , wonder what nose cone does they have ..!!
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Re: LCA Tejas: News and Discussions

Post by Sid »

Shaun wrote:^^^^ BVR missiles firing one of the key point for FOC and the present nose cone doesn't support 2032 to fire 77 at its full range.
some Jaguars have EL/M 2032 , wonder what nose cone does they have ..!!
NEZ for R77 cannot be not greater then 20-25 miles. Derby I guess is even less then that (same motor as Python 5). More then sufficient for current nose cone.

We are testing launch platform not certifying the weapon system capabilities.
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Re: LCA Tejas: News and Discussions

Post by Aditya_V »

Shaun wrote:^^^^ BVR missiles firing one of the key point for FOC and the present nose cone doesn't support 2032 to fire 77 at its full range.
some Jaguars have EL/M 2032 , wonder what nose cone does they have ..!!
Jaguars dont have any BVR missile, Magic II which is being replaced by ASRAAM. and besides LCA front is Indian only some back stuff is Israeli, so cnat exactly compare with EL 2032.
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Re: LCA Tejas: News and Discussions

Post by Prasad »

What about the harriers? They can fire bvr missiles using a similar radar.
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Re: LCA Tejas: News and Discussions

Post by negi »

Harriers have been down to single digits for quite some time now and will be de-commissioned next year.
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Re: LCA Tejas: News and Discussions

Post by Gyan »

The issue is, when were the orders placed on Chobam?
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Re: LCA Tejas: News and Discussions

Post by Philip »

I've made a point about accelerating the AMCA project in that td. precisely because of the fear that we will do an HF-24 to the LCA.The time being taken to perfect Mk-1,planned timeframe for Mk-2 and rate of production is simply too little and too late for the LCAs,MK-1/2 to make a major contribution to the IAF's future order of battle. If we use them for close support/GA and point defence,they will serve the purpose of replacements for the MIG-21s. Even for this purpose the programme has to kicked in the backside. But for more challenging tasks in the battle for air space and strike post 2020 with the advent of many new stealth birds,the relevance of the AMCA only increases,as the FGFA is a larger aircraft comparable to the F-22. The AMCA could be our F-35/JSF. With the Rafale decision expected shortly,the MOD/IAF must review the LCA programme minutely,the IAF's future fleet structure from 2020 and beyond and take some hard decisions on the LCA, to shorten the timeframe and increase production asap,or to look to the future with the AMCA. .Languishing in limbo only makes a charade of the entire exercise.
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Re: LCA Tejas: News and Discussions

Post by Aditya_V »

Prasad-> with Harriers, I guess with no other choice the navy was fine with a limited BVR capability rather than IAF wanting fighter targets to be engaged at 80-90KM, probably keeping future use in mind now that PAF has block 50/52's with an Inventory of 500 AMRAAM-C's.

Looks like this was an afterthought which was not there initially but evolved after the proliferation of F-16's with AMRAAMS in 2005-15 period.
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Re: LCA Tejas: News and Discussions

Post by shaun »

Aditya_V wrote:Jaguars dont have any BVR missile, Magic II which is being replaced by ASRAAM. and besides LCA front is Indian only some back stuff is Israeli, so cnat exactly compare with EL 2032.
Well Sir , I guess that is over simplification .

LRDE contribution to MMR is X-band slotted wave guide array antenna and BARC's contribution in developing gimbal design for the EL-2032 . I have no idea about the Indian origin signal processor and software that went in MMR
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Re: LCA Tejas: News and Discussions

Post by shaun »

Aditya_V wrote:Prasad-> with Harriers, I guess with no other choice the navy was fine with a limited BVR capability rather than IAF wanting fighter targets to be engaged at 80-90KM, probably keeping future use in mind now that PAF has block 50/52's with an Inventory of 500 AMRAAM-C's.

Looks like this was an afterthought which was not there initially but evolved after the proliferation of F-16's with AMRAAMS in 2005-15 period.
At sea level , the range of any AAM will decrease compared to high altitude release. And anyway those are for self protection rather than for offensive purpose, where you need long range AAMs
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Re: LCA Tejas: News and Discussions

Post by shaun »

LCA Mk1 and Mk2 both will be needed even if AMCA comes online . It is same like we have upgraded mig-29s and Mirage 2000 flying till next decade even though we have su-30 mki and LCA being inducted .

The geo political situation that we had when developing HF-24 is different to what we have now. LCA have no problem in getting the best engine from world market and it do have the best engine compared to the entire IAF inventory . AMCA will be in testing phase in only later half of next decade till then we have to make lots of LCA .
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Re: LCA Tejas: News and Discussions

Post by Thakur_B »

Good read on why LCA Navy Mk-1 has exceeded design parameters and design considerations of Navy Mk-2.

http://thumkar.blogspot.in/2015/03/lca-navy-succeeding-through-success.html
Success from Failure

Failure of an endeavor is often just a turning point on the road to success. Failure is never absolute; it can at best be defined as lack of success. Sometimes, failure can even be redefined as success.

The Indian Government sanctioned Full Scale Engineering Development (FSED) of Naval Light Combat Aircraft (LCA-Navy), capable of operating from an aircraft carrier, on March 28, 2003 with a PDC of March 27, 2010. Had the Indian Government defined LCA Navy as a technology demonstrator project, which is what it has ended up becoming, there would have been no doubt about the resounding success of the project!

As a technology demonstrator project, the LCA leaped out of doldrums when Navy Prototype 1 (NP-1) successfully executed its first ski-jump take-off at the SBTF in Goa on December 20, 2014.

NP-1 attempted the ski-jump after a 300-m roll in clean configuration presumably with full internal fuel. The safe take-off required 150 knot at a climb rate of 6.4 degrees. But, the aircraft bested the benchmark with a climb rate of around 11 degrees.

The flight also validated the hands-off take-off algorithm of LCA Navy's Flight Control Software (FCS).
Reason for Better than Expected Performance
Press reports on the better than expected climb performance of NP1 have been confusing. Here is simple and precise explanation.

The LCA's GE-F-404-IN20 engine needs be at 80% RPM for around 5-min for it to give assured peak thrust at full throttle. Since it's not practical for an operational aircraft to wait for 5 mins before take-off, ADA had factored in the lower than max thrust when calculating expected rate and angle of climb on leaving the ramp. The aircraft designers were pleasantly surprised when due to higher than expected thrust NP1 outperformed the conservative calculations.

It's now clear that LCA Navy Mk-1 could carry more weapons and fuel than initially thought.

At Aero India 2015, IDP Sentinel asked LCA Navy Project Director Commodore CD Balaji if the better than expected performance could result in the aircraft being operationally deployed on a carrier, were the LCA Navy Mk-2 project to be delayed.

"LCA Navy Mk-2 will not be delayed," said Balaji with a lot of confidence. "We are close to freezing its design, which has been simplified. The new design would be easy to implement."



LCA Navy Mk-2

Commodore Balaji's confidence was eye-opening - The biggest pay-off from the LCA Navy project may well be ADA's increasing confidence in its ability to tweak fighter aircraft design to squeeze out better performance. This is evident from the following

LCA Navy Mk-2 has been designed from the ground up as a Navy fighter, independently of Tejas LCA Mk-2.

The fuselage of the aircraft has been broadened and the wing roots moved outwards. As a result, aircraft design has been optimized for supersonic flight with perfect conformance to area rule. (Tejas LCA and LCA Navy Mk-1 do not conform perfectly to area ruling resulting in high supersonic drag.)

Mid section fuselage broadening allows undercarriage bays to be shifted outwards, allowing a simpler, straight and light undercarriage as in the Rafale.

Mid section fuselage broadening also increases fuel capacity.

That is three birds with one stone!
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Re: LCA Tejas: News and Discussions

Post by JTull »

Wouldn't this 'broadened' LCA Navy Mk-2 fuselage and corresponding bulging out of the air intake reduce the front-on radar view of the engine blades?
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Re: LCA Tejas: News and Discussions

Post by narmad »

Thakur_B wrote:Good read on why LCA Navy Mk-1 has exceeded design parameters and design considerations of Navy Mk-2.

http://thumkar.blogspot.in/2015/03/lca-navy-succeeding-through-success.html
Success from Failure

LCA Navy Mk-2

Commodore Balaji's confidence was eye-opening - The biggest pay-off from the LCA Navy project may well be ADA's increasing confidence in its ability to tweak fighter aircraft design to squeeze out better performance. This is evident from the following

LCA Navy Mk-2 has been designed from the ground up as a Navy fighter, independently of Tejas LCA Mk-2.

The fuselage of the aircraft has been broadened and the wing roots moved outwards. As a result, aircraft design has been optimized for supersonic flight with perfect conformance to area rule. (Tejas LCA and LCA Navy Mk-1 do not conform perfectly to area ruling resulting in high supersonic drag.)

Mid section fuselage broadening allows undercarriage bays to be shifted outwards, allowing a simpler, straight and light undercarriage as in the Rafale.

Mid section fuselage broadening also increases fuel capacity.

That is three birds with one stone!
Why can't this Naval Mk2 design be standardized as Airforce Mk2 [ or Mk3 if Mk2 is already too far ahead in the game ] with a lighter undercarriage ?
What would be the disadvantages of using the Naval design for Airforce ?
And would those disadvantages outweigh the commonality of design and spares from maintenance point of view ?
Can any of the Gurus spend some grey matter on this thought ?
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Re: LCA Tejas: News and Discussions

Post by ramana »

KaranM, I have been following LCA saga since the late 80s. Interavia had articles by Hormuz Mama that clearly showed the lineage. Yes its from the Ajeet. Concept design for replacement Ajeet class plane was in 1984. Then all sorts of add-ons went on.

narmad, Already IAF is doing ehsaan on India by accepting the LCA.
Don't make them accept naval version of LCA!!!
They will rather ground themselves than do that.
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Re: LCA Tejas: News and Discussions

Post by Surya »

So are saying that IN has more people who have a clue about aircraft design than the IAF :D
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Re: LCA Tejas: News and Discussions

Post by kuldipchager »

Surya

Post subject: Re: LCA Tejas: News and Discussions

PostPosted: 05 Mar 2015 20:36



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So are saying that IN has more people who have a clue about aircraft design than the IAF :D



We have a problem the Pro-western lobby. If LCA is chines fighter they would have produce 1000, 1000 planes already and exported so many.
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Re: LCA Tejas: News and Discussions

Post by member_26622 »

IN knows more about their business than IAF. If IN went the IAF route we would have had only a 10 ship navy.... :roll:

Sarcasm-IAF is more akin to a safe to raided for $$$ by politicos and arms peddlers
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Re: LCA Tejas: News and Discussions

Post by JTull »

Surya wrote:So are saying that IN has more people who have a clue about aircraft design than the IAF :D
IN is designing LCA Navy Mk-2 to their own needs.
ADA is designing LCA Mk-2. IAF has contributed to the program by moving the goal posts.

Waiting for the day when we see a flight of IAF Mk-2 come up against a flight of Navy Mk-2 in TACDE. I know my money would be on which one.
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Re: LCA Tejas: News and Discussions

Post by putnanja »

Surya wrote:So are saying that IN has more people who have a clue about aircraft design than the IAF :D
Could be :lol:

The main thing is that IN has taken joint ownership of the project and they are driving it to where they want it to be.

IAF till recently appeared to be a reluctant customer. I think the PM's make-in-india made them somewhat more receptive to LCA due to compulsion.

IN will take the iterative improvements and make it their own. Irony that IN will help the mil-aviation growth in India compared to IAF.
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Re: LCA Tejas: News and Discussions

Post by member_23360 »

Surya wrote:So are saying that IN has more people who have a clue about aircraft design than the IAF :D
IN has required mindset to harness indigenous resources, because till recently their share in defence budget was less ..

anyways, with PM's push IAF will fall in line :wink: :D
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Re: LCA Tejas: News and Discussions

Post by Indranil »

Some very nice points brought out by the article, and by Kartik's visit to the ADA booth. What a world of good can be found out when knowledgeable people ask the right questions. There is confirmation of the area ruling (huge hump) and the extra fairing so that the NLCA can have straight MLGs. I would have loved to see a shot of the model from the bottom.

Thakur_B wrote:
LCA Navy Mk-2

The fuselage of the aircraft has been broadened and the wing roots moved outwards. As a result, aircraft design has been optimized for supersonic flight with perfect conformance to area rule. (Tejas LCA and LCA Navy Mk-1 do not conform perfectly to area ruling resulting in high supersonic drag.)
I don't know if Thakur sahab (the blogger) meant it that way. But broadening the aircraft at the middle is contrary to area ruling. What they have done is increased the fineness ratio, i.e. they have increased the length by a proportionally larger amount. Also the area curve of the Mk1 is not perfectly smooth at certain points, especially near the inlets. This they have made smooth. I wrote about this earlier.
indranilroy wrote: I take it back. I see what you are saying. It is definitely for area ruling. The have done a 747 :wink: . The hump behind the cockpit starts to recede only where the new fairing for the MLG starts to grow (just behind the inlet) and dissapears where the fairing is fattest!

Image

Image
JTull wrote:Wouldn't this 'broadened' LCA Navy Mk-2 fuselage and corresponding bulging out of the air intake reduce the front-on radar view of the engine blades?
No. The compressor blades were never visible on the LCA. In NLCA2, the bulging is only the to accommodate the landing gear. The inlet stays more or less unaltered. The RCS of NLCA-Mk2 will have higher RCS than the LCA-Mk2, as it provides larger frontal area.
narmad wrote: Why can't this Naval Mk2 design be standardized as Airforce Mk2 [ or Mk3 if Mk2 is already too far ahead in the game ] with a lighter undercarriage ?
What would be the disadvantages of using the Naval design for Airforce ?
And would those disadvantages outweigh the commonality of design and spares from maintenance point of view ?
Can any of the Gurus spend some grey matter on this thought ?
[/quote]

Not a guru. Just thoughts.

Airforce Mk2 is optimized for its requirements. You don't need the large MLGs, so you don't need those extra fairings. If you don't needs those fairings, you don't need that much extra length. If you have a smaller plane, you save on weight, which means better TWR. With better TWR, you have better acceleration and agility. NLCA Mk2 will have higher range, but LCA Mk2 will be more nimble. And though both will have similar top speeds, LCA mk2 will get their faster. LCA mk2 will also have a smaller RCS.
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Re: LCA Tejas: News and Discussions

Post by disha »

For nanha mujahids - to understand what Gurulog here is talking about, please go through this video (very very informative., explained by the guru himself)



After this., there should be *NO* question from nanha mujahids on why LCA is "bottle shaped" OR even why LCA is "not bottle shaped" after watching the above video.

Personally, I like the NLCA - will love the NLCA Mk2.

Indranil'ji - request to check out the underbelly of A380 to get an idea of the underbelly of the NLCA-Mk2.
Last edited by disha on 07 Mar 2015 05:02, edited 1 time in total.
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Re: LCA Tejas: News and Discussions

Post by member_28788 »

Shaun wrote:Cobham seems to be delaying the project ( delaying tejas to get FOC )by not supplying nose cones and refueling probes on time ..is it deliberate ??
There has to be more to story. Supplier relations are every intricate. ADA would be wise to know that and just like us they could have anticipated these issues too. If they went ahead inspite of this then they must have been very acutely limited in their choices. But I think they knew better. There has to be something more to this.
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Re: LCA Tejas: News and Discussions

Post by Indranil »

disha wrote: Indranil'ji - request to check out the underbelly of A380 to get an idea of the underbelly of the NLCA-Mk2.
No 'ji' for me please.

I don't get the similarity of the underbellies. In the 380, the MLGs retract into the fairing attached to the fuselage. The MLG attached to the the wing retracts sideways into the fuselage fairing. In the NLCA Mk2, the fairings seem to be attached to the wings. The MLG retracts straight up into this fairing.

To me the idea seems like this. Look at the bottommost right picture. You can see how the the decrease in the crosssectional area of hump coincides with the increase in the area of the MLG fairing. The fairings themselves taper of (somewhat like Kuchemann's carrots) under the wing.
Image
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Re: LCA Tejas: News and Discussions

Post by Indranil »

disha wrote:
What a legend!
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Re: LCA Tejas: News and Discussions

Post by Cosmo_R »

"With the advent of more powerful jet engines, “drag rise become less of a factor because you have enough power to bulldoze through it,” says Martin. That’s why designers of the Typhoon or the Lockheed Martin F-35 Lightning II don’t give a moment’s thought to drag rise; engines on those aircraft have plenty of brute force to overcome it."

"The area rule, says Martin, is simply “a tool or a technique,” one that has little relevance to today’s military jets.

http://www.airspacemag.com/need-to-know ... 57/?no-ist
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Re: LCA Tejas: News and Discussions

Post by Indranil »

Cosmo_R wrote:"The area rule, says Martin, is simply “a tool or a technique,” one that has little relevance to today’s military jets
^^^ People write and believe all kind of crap. Area rule is not about pinching the waist. That is only one application of the theory!

Area rule says that abrupt increase or decrease in the cross sectional area increases wavedrag substantially. So, the pinching of the waist offsets the increase of the area due to the wing. In this way, you can completely eradicate the wave drag due to the wing. There are other ways. For example on the EF itself, the mitigation of the area behind the cockpit coincides with the increase in the area of the wing. Later on the fuselage fattens out to coincide with the decrease in the area of the wing!
Image

Also many modern fighters do use "brute-force" to fly through the sonic barrier. But that is only a small part of the envelop. Most of the time fighters fly subsonic. Aerodynamically, they are optimized for about 0.7-0.9 M. And if f you have a plane which follows the area rule more closely than the other, then such a plane will have better range and endurance. This is not a matter of opinion or design choice, it is matter of physics. And there is no running away from the latter. This is why the Gripen is aerodynamically sleeker than Mk1. And this is why the Mk2 is being lengthened and all kinks in the area curve removed.
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Re: LCA Tejas: News and Discussions

Post by Philip »

True.The various statements put out by those associated with the project at the air show,reveals that there will be significant "tweaking" of the MK-2's aerodynamics,fuselage extn.weight reduction to be aimed at 500kg,greater modularity of components for easier maintenance/replacement,etc. I've mentioned some in an MMRCA post. The IN plans for 56 NLCAs,a v,large amt. considering that we've already bought 45+ MIG-29Ks with 3 sqds. of them to be formed,latest report,2 on the two carriers and one on land for training. The IN perhaps has planned for some of its air assets to be land based in defence of naval bases/establishments and also based at our naval air stations in the island territories. If done it would release some of the IAF's assets top be relocated where they matter most,facing China and Pak.
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Re: LCA Tejas: News and Discussions

Post by shiv »

Cosmo_R wrote:
"The area rule, says Martin, is simply “a tool or a technique,” one that has little relevance to today’s military jets.

http://www.airspacemag.com/need-to-know ... 57/?no-ist
That is rubbish.
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Re: LCA Tejas: News and Discussions

Post by sankum »

LCA MK2 Weight Estimate based on latest data.

Empty weight= 6060Kg

Internal fuel= 3140Kg approx.

Clean Take off weight=10000Kg

External payload=5000Kg

MTOW= 15000Kg

6060 kg empty weight+ 3140 kg internal fuel+ 500 kg pilot wt/cannon ammo/ chaff/flare/weapons pylon wt+ 300 kg(2*close combat missile)+ 5000 Kg external payload=15000 Kg
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Re: LCA Tejas: News and Discussions

Post by Indranil »

I get the basis of your empty weight, but how are you arriving at the internal fuel and external payload numbers?
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Re: LCA Tejas: News and Discussions

Post by sankum »

Philip wrote on march 5, 2015 in rafale and mmrca news discussions-9 August, 2014

Some quotes,
Proj. Dir LCA: "MK-2 is conceived to improve performance and maintainability over Mk-1.Issues which could not be addressed in Mk-1 have been clearly understood and ..addressed in MK-2".
"..additional systems to enhance capabilities and address obsolescence"
Apart from several significant improvements like a Unified EW system (EUWS),desi OBOGS and IFRS,AESA radar (project Uttam),preferred to the Israeli ELTA 2050,new DFCC,new avionics with 6"X8" MFDs,aerodynamic improvements,more powerful engine,etc., the MK-2's AUW will be 15t and can carry an additional 1500kg.
"The original sanction was only to change the engine,but when the design conceptualization started many new system enhancements and capabilities as mentioned above got introduced".
"PDR completed,clearance given for the Detail Design phase."

In another report,"MK-2 has 25% commonality with Mk-1"
This was confirmation of what a blogger has quoted in his blog of MTOW of 15T and payload of 5T.

Internal fuel is by way of calculating backwards is there fore approx.
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Re: LCA Tejas: News and Discussions

Post by NRao »

"The area rule, says Martin, is simply “a tool or a technique,” one that has little relevance to today’s military jets.
I have been told that today's modeling methods take a lot more into consideration than what was considered leading edge in those days. Material, stealth, this reflection and that reflection, etc. Not surprised that the old ways have been sidelined. The F-16 changed a lot of "rules".
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Re: LCA Tejas: News and Discussions

Post by brar_w »

They haven't been sidelined. They are very much relevant today as they were yesterday, as they would be tomorrow. You always have to balance design goals, be it payload, range, weapon bays, stealth and what not. Sometimes you have sacrifice one area for the other (stealth vs aero for example that drove Overholser crazy during early days of that technology) and one way you make up is by putting those requirements into propulsion to help you manage the risk and overcome the compromises to some extent. Usually its up to the customer/requirement-framer to come up with a modeling approach to analysis of the various capabilities and assign value to each one. You need to be clear about whether you are willing to sacrifice X db of RCS vs a particular transonic performance or are able to let go of X amount of internal/payload range for the sake of signature or other performance metrics (acceleration, turn, altitude etc etc). Once you establish those priorities, hoping that you are well aware of the trade-offs you ask your builders to build a product as per spec.
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Re: LCA Tejas: News and Discussions

Post by Indranil »

brar_w wrote:They haven't been sidelined. They are very much relevant today as they were yesterday, as they would be tomorrow. You always have to balance design goals, be it payload, range, weapon bays, stealth and what not. Sometimes you have sacrifice one area for the other (stealth vs aero for example that drove Overholser crazy during early days of that technology) and one way you make up is by putting those requirements into propulsion to help you manage the risk and overcome the compromises to some extent. Usually its up to the customer/requirement-framer to come up with a modeling approach to analysis of the various capabilities and assign value to each one. You need to be clear about whether you are willing to sacrifice X db of RCS vs a particular transonic performance or are able to let go of X amount of internal/payload range for the sake of signature or other performance metrics (acceleration, turn, altitude etc etc). Once you establish those priorities, hoping that you are well aware of the trade-offs you ask your builders to build a product as per spec.
True.
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Re: LCA Tejas: News and Discussions

Post by Kartik »

sankum wrote:LCA MK2 Weight Estimate based on latest data.

Empty weight= 6060Kg

Internal fuel= 3140Kg approx.

Clean Take off weight=10000Kg

External payload=5000Kg

MTOW= 15000Kg

6060 kg empty weight+ 3140 kg internal fuel+ 500 kg pilot wt/cannon ammo/ chaff/flare/weapons pylon wt+ 300 kg(2*close combat missile)+ 5000 Kg external payload=15000 Kg
I really doubt that empty weight figure. The Mk1 itself weighs 6600 kgs empty, and with additional fuel and payload, internal EW suite, OBOGS and a higher thrust engine, which requires some corresponding fuselage strengthening, I have serious doubts that such a low empty weight will be realized. if they even manage to keep it at the 6600 kg mark, it will be an achievement.

They're setting themselves up for another round of criticism by quoting low target empty weight figures. People like Prodyut Das will still call the Mk1 overweight because it doesn't weigh 5600 kgs, as originally targeted, despite the fact that every other light jet with any combat capability weighs about 6500 kgs empty. But one must remember, the Gripen NG weighs almost 1000 kgs more than the Gripen C. Prior to that, their sales brochures were quoting unrealistically low figures as well.
member_28700
BRFite -Trainee
Posts: 31
Joined: 11 Aug 2016 06:14

Re: LCA Tejas: News and Discussions

Post by member_28700 »

Saw this on idrw.org. Not sure what sense to make of it. The data in this shows that our LCA is no match even for the bandar :cry:
What does the Gurus' analysis say?

http://idrw.org/archives/59478
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