LCA: News & Discussions - October 2016

[tushar_m]

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R-73
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100kg - ELTA EL/L-8222
105kg - R-73
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205kg

105kg - R-73
105kg - R-73
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210kg


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Python-5
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100kg - ELTA EL/L-8222
105kg - Python-5
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205kg

105kg - Python-5
105kg - Python-5
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210kg

The weight of the multi-launcher should also be considered while calculating the overall weight. Do we have any idea what the multi-rack launcher weights ?

[Singha]

the harrier is definitely a british design - ugly, quirky but innovative

[shiv]

Again off topic but can someone educate me on what sort of brain fart was required to put either wingtip tanks OR Sidewinders on the F-104 Widow Maker?

Germans demanded more fuel capacity (among other things) for the Luftwaffe to buy it. One of the reasons it became the Widow Maker.

Earlier models did not have anything on the wing tip.

Interesting - but Wiki shows wingtip tanks in an image of the first F-104 prototype
https://upload.wikimedia.org/wikipedia/ ... XF-104.jpg

But if tanks were an afterthought - it means that the wing was overengineered

[shiv]

Dunno how this works or what it proves, my nephew could easily lift the chairs.... I couldn't though. We are the same height. Seems that age plays some role?

It is a simple physics lever experiment in which the distance between fulcrum (base of spine) and mass (chair) is shown to be greater in men and therefore requiring an effort that most human back muscles cannot achieve without slipping a disc. This is a bad baaad experiment and can damage one's back if it is turned into an ego issue, but good for spine surgeons who may get to operate on your back . Your nephew - presumably much younger probably just has the required muscle strength and resilience to manage it. By resilience I mean that his spine as a whole is more compressible allowing his spine to shorten as he puts in the effort, allowing him to lift that chair. Not good even for young people though.

In the original TV show video above the actress (wotzername) flinches the first time she lifts it. That was a spine damaging "moment" pun unintended

[vina]

Dunno how this works or what it proves, my nephew could easily lift the chairs.... I couldn't though. We are the same height. Seems that age plays some role? ..

It is a simple physics lever experiment in which the distance between fulcrum (base of spine) and mass (chair) is shown to be greater in men and therefore requiring an effort that most human back muscles cannot achieve without slipping a disc

Exactly. So what it means is that where you suspend the weight will have a massive effect on the load capacity . Throwing veribage like "Outboard Pylon" and saying Harrier carries more there than LCA or ABC or whatever is thoroughly misleading . The spans of the LCA and Harrier are roughly the same, while the "outboard" pylon of the Harrier is roughly 2/3 of the way out, while the mid board pylon of the lCA is 2/3 of the way out. The "outbaoard" of the LCA is nearly ALL the way out. So, if you want to do an apple to apple comparison, sure compare the "Outboard" of the Harrier to the "Midboard" of the LCA. This experiment was meant to show that basic lever and moment stuff that we learn in high school.

Now if you insist "Outer = Outer, right? Since when did middle of wing become outer?" and then do a bait and switch and put George Bush 41 == George Bush 43, and argue, what can I say. It is like arguing Women are physically stronger than men because the experiment "proves" that women lift a certain weight while men are unable to.

[NRao]

Germans demanded more fuel capacity (among other things) for the Luftwaffe to buy it. One of the reasons it became the Widow Maker.

Earlier models did not have anything on the wing tip.

Interesting - but Wiki shows wingtip tanks in an image of the first F-104 prototype
https://upload.wikimedia.org/wikipedia/ ... XF-104.jpg

But if tanks were an afterthought - it means that the wing was overengineered

Cannot speak to wiki content (anyone can say anything - I have tried to correct and failed). But, there are early sketches and wooden models, without wing tip tanks or anything. That was Kelly's instructions - design a very high speed, light weight plane. Consequently it had very little range or armament. The only two reasons the Germans bought it (over a British designed rocket plane as this too was called) was the mods to the plane, which bloated it and made it rather unstable and bribes, which led to Prez Carter, two decades later, enacting the Foreign Bribe law or some such thing.

[tsarkar]

I stand by my PoV that IAF & IN added new missiles as older ones became obsolete, and their aircraft, whether MiG-21 or Sea Harrier, had hardpoints with adequate margins to allow them do so without major re-design as required for Tejas outer wing hard point.

I would be happy to learn incase you have any alternate / additional facts and logic to my above PoV.

Please show if you can, a reference saying Harrier's outboard pylons were *designed only for CCM* of the 1970's era, but could easily take not only new CCM but two AAM on the same pylon without redesign. That would be a fact showing your POV is correct.

Leaving all the factual knowledge aside and without having any knowledge about any aircraft whatsoever, just by knowing how the structural design methodology has evolved over last 50yrs, one can argue that the Harrier was over-designed for given load. That is with the 1960's methodology it was designed say for 100kg, but since the design methodology was less mature, the design actually was more than necessary. Later with improved methodology the OEM could certify the same pylons for higher loads cutting down on the conservatism in the initial design. Now the same pylon is certified to carry say 200kg load without any need for redesign. I have seen such correction in methodology for structural design personally in one of our own product. And I know other such examples from Aerospace industry, both in Metals and composites. You know how F15 seems to have never ending airframe life..? Because they were over designed. Would the designer over designed the aircrafts so much that they can have 3 or 4 times intended life at the height of cold war, if they knew with 99% confidence that they are over designing..?? Obviously not.

Nowhere have I said that Sea Harrier outboard wingpoints were designed only for AAMs. Nor was it over-designed as per your note. The designers knew precisely what they were doing.

Engineers in US, France (Balzac), Russia and UK were trying to build jump jets and the constraints were always the engine.

Getting enough power from the complex engine to enable the aircraft carry ample fuel and useful load was the key design challenge. Other aircraft (Balzac, Yak-38) had to carry the deadweight of lift jets.

The beauty of the Harrier is that despite the limited power from the complex engine, small wingspan dictated by keeping weight low and carrier operations, they still ensured a useful payload of 3600 kg and the hardpoints were sufficiently stressed for heavy loads.

Coming to the larger point I'm making -

Sea Harrier initially used Matra Magic 1, then upgraded to Magic 2 and finally Derby. 8222 pod was added. There were plans for Litening, Paveway, Griffin, Harpoon integration that was dropped since the aircraft was to be retired in the next 10 years. No structural design or build changes required.

MiG-21 initially used K-13, then R-60, then Magic-1/2, then R-73 & R-77. When K-13 was the "latest" missile, no one knew in future R-77 would be an option. Yet for all these evolutions, No structural design or build changes required.

Jaguar is getting new weapons every 5 years. HSLD, CBU-105, Harpoon, etc. No structural design or build changes required.

MiG-29 9.12 too carried R-60 in its outer pylons. The outer pylons were designed to carry only AAMs. Yet when R-73E became available, No structural design or build changes required.

Mirage 2000 was designed around Matra BGL, took Griffin & Paveway & Crystal Maze. Magic in outer pylons replaced with heavier MICA. No structural design or build changes required.

Only in case of Tejas is the constraint that outer hardpoint was designed around R-60 and could take nothing else without re-design.

Nothing against ADA - they were doing it for the first time, and its an oversight that was correctly rectified.

Issue is the Lahori Logic in the forum that user is unreasonably adding "new weapons" or other designers just got lucky.

Isn't it funny that MiG, Sukhoi, Dassault, BAe are not doing any rona dhona on user being unreasonable?

Guess which way user will gravitate? The design requiring structural changes or the design with growth margins?

[srai]

R-60 was a very lightweight AAM at 43kg. To jump from that to more than two times to 105kg in R-73 is a lot. In any case, this is bridge under water so to speak. Current hardpoint is rated at least at 150kg (possibly more like 250kg with the ongoing simulation studies with dual rack for SPJ).

The other mid-wing (800kg) and inner-wing (1200kg) pylons were designed for carrying heavier loads. Plus, the centerline is also rated at 1200kg. Those are the points where BVR AAM, 250kg/450kg HSLD, 1000lb bomb, LGB, ASM and other PGMs would be integrated. Some on multi-racks as well. No structural changes required on those.

[JayS]

Interesting - but Wiki shows wingtip tanks in an image of the first F-104 prototype
https://upload.wikimedia.org/wikipedia/ ... XF-104.jpg

But if tanks were an afterthought - it means that the wing was overengineered

Cannot speak to wiki content (anyone can say anything - I have tried to correct and failed). But, there are early sketches and wooden models, without wing tip tanks or anything. That was Kelly's instructions - design a very high speed, light weight plane. Consequently it had very little range or armament. The only two reasons the Germans bought it (over a British designed rocket plane as this too was called) was the mods to the plane, which bloated it and made it rather unstable and bribes, which led to Prez Carter, two decades later, enacting the Foreign Bribe law or some such thing.

I was watching a documentary on F104 just a couple of days ago. The first flight video in that one does not show any wingtip tanks in it. But they also showed expt tests using rockets which were conducted in the design stage. Those show wingtip tanks and missiles tested. From the documentary, one gets the impression that the F104 was designed purely as an interceptor but USAF wanted a multirole aircraft. In order to satisfy USAF LM tried everything. This is even before the German SQR were defined. Its rather difficult to find what was the starting point for wingtip tanks based on casual googling.

https://www.youtube.com/watch?v=fChqJY9VzTU

[tsarkar]

tsarkar, Your posts are very informative. but get colored with needless rhetoric. Can you refrain from needless flame baits of LL and MM?

Thanks,
V/R

ramana

Dear Ramana,

There is no Forum Feedback thread, so I'm responding here. Before here, I did not know troll, flame bait, etc meant, which is something HNair also accused me of. I still do not know what LL & MM means.

Now, I research extensively before posting, ask knowledgeable people, double check on the internet, to ensure my posts are factual. I'll be happy if anyone points out any mistakes in my posts.

The reason I write harshly occasionally is because of outright lies, like unreasonable user changed specs, when so many legacy and current aircraft are concurrently getting AAM & other upgrades without structural design & build changes and rona dhona. Or Mirage 2000 not being a CCV or had AAMs. Or ships being like whales and crumbling.

If my questioning dishonesty causes cognitive dissonance, I will gladly excuse myself. I know enough about group dynamics & behavior. The following books also illustrate what I'm referring.

https://en.wikipedia.org/wiki/The_Country_of_the_Blind
https://en.wikipedia.org/wiki/Lord_of_the_Flies

The question I ask you & forum members what is the Forum's re-course to address dishonesty?

A person blatantly lies Mirage 2000 not being a CCV and did not have any missiles. That lie supports beliefs held sacred here. So should the lie be allowed to propagate?

What happens when forum members meet better informed people in the real world and tell them,"Mirage 2000 not a CCV and didn't have missiles" or IAF "unreasonably added R-73E"? Wont they be making utter fools of themselves? What happens to the credibility of the forum & its members?

Time challenges did not allow me respond & complete some of the earlier discussions.

I mentioned earlier that a BVR missile and its carrier aircraft need to have their respective envelopes sync up via testing to ensure better Pk.

A member responded that just ensuring safe clearance of missile and guiding by radar is good enough and IAF is needlessly insisting on extensive testing.

Its the bloody user's problem of maximizing Pk.

Such logic will do wonders for export potential of Tejas. Tell export customers that the missile drops and clears neatly and guides by radar. Export customers can figure out themselves maximizing Pk.

Potential Tejas customers, countries like Vietnam, that buys approx 40 aircraft a decade, and lacks instrumented ranges - will be overjoyed to hear this export pitch. They're a small country with limited resources facing a large aggressor. Every bit of effort is focused on countering the aggressor.

They will be overjoyed on learning they will need to spend more money than the cost of planes + missiles in building an instrumented range to mate missile & aircraft performance envelopes to maximize Pk. And do it again when the missile becomes obsolete in a decade.

And after such brilliant logic, the forum will then wonder why indigenous equipment doesn't sell anywhere, and come up with more conspiracy theories.

I rest my case, and excuse myself humbly apologizing to all.

[shiv]

As I see it, in the context of the ongoing discussion, a Sidewinder (early model) probably weighed 80 kg. But wingtip tanks with fuel would weigh something in excess of 300 kg even with 100 gallon tanks. If the F 104 wing had been designed only for Sidewinders, then it would have needed major redesign to hold tanks. Or it was grossly overdesigned. Judging from images of wingtip tanks on the F 104 early in its prototype phase, it is most likely that tanks were envisaged from the outset and that it was neither overdesign nor a German requirement

[RKumar]

tsarkar, with due respect.

What are the expectations from the smallest bird in the world? - Should it be able to carry loads equal to Su-30. There is a reason it is being called light combat aircraft. We always complain that undercarriage is over-designed which caused LCA obesity. If you expect to hung 250 kg when original aim was 45 kg, it is not going to work. May be they require bigger, healthy and grownup AMCA not light, small and skinny LCA SRDE.

Our designer might be lazy, crazy, poor SDREs with bad teeths, they try their best to solve given problems. We know their best efforts are never good enough for our own very end users. But there will be day, then our users will realise the benefits of local products. For now, half ready non-tested and non-touched foreign products are far better than half ready but extensive tested local products.

[NRao]

Sorry, posting from my cell.

You are right that the original design did cater to a wing tip that could take a lot of weight - in fact the tank out there held around 170 gallons or 500+ Kgs.

Very long story, but in a nutshell:

Kelly designed it based on what pilots told him - they wanted speed, thus the pilot-on-a-rocket, very thin and short wings, etc. But that made the plane very small, therefore low range, not much munition for anything. No "tank" was a major part of his design.

So, the USAF was dissatisfied with it. (A) In fact the USAF, very quickly, moved to the F-105 and F-106. (B) Which forced Lockheed to sell abroad (lack of USAF orders).

Now coming to the wing tip (and center-line tank), to a great extent because of (A), the USAF opted for IFR and munition on the wings. Because of (B), Lockheed was forced to cater to the foreign clients (more than the USAF), headed by Germany and thus produced a heavily modified F-104

Two diff planes. The USAF never did rely on teh wing tip tank. While NATO used it to putter around a stunted Europe. And, of course, the Pakis got their behinds kicked against the -21s during the Indo-Pak war.

Shiv,

try the F-89: http://files.abovetopsecret.com/files/i ... 688517.jpg

[Lalmohan]

have seen F104's at airshows - turning circle of a container truck!

[JayS]

Nowhere have I said that Sea Harrier outboard wingpoints were designed only for AAMs. Nor was it over-designed as per your note. The designers knew precisely what they were doing.

Only in case of Tejas is the constraint that outer hardpoint was designed around R-60 and could take nothing else without re-design.

See the difference in the bolded parts? That what I was trying to highlight in my earlier post where I posted those pictures with outboard pylon carrying bombs and rocket pods. Harrier outer pylon was designed for much heavier bombs and rocket pods. Had they been designed only for single AAM (and did not have outrigger wheels sitting on the wingtip) and then they could carry next generation heavier missiles then it would have been correct to say the designers kept margin for future growth in AAM weight.

You cannot take a pylon designed to take bombs and Rocket pods along with AAM and then compare it with another pylon which was only designed for AAM. Putting leter generation AAMs or 2x AAM on the pylon was still within the originally designed load of the pylon. There is no margin here we are taking about.

Had LCA's outboard pylon been designed for 500lb bombs or rocket pods instead of mere R60 AAM, it would also have taken 2x weight of R73 without sweeting.

Also you cannot compare a pylon on a wing which has bulky outrigger wheel on wingtip outboard of the pylon and a pylon on a wing which has zero load on wingtip. Simple physics - A wing which can support outrigger wheel (definitely as heavy as an AAM at least, I would say heavier than an AAM of 1970's era AAMs.) on wingtip would out of the box support significantly more load on the pylon which is inboard of the wingtip, as compared to a wing which has zero wingtip load.

This is not an apple to apple comparison. With MiG21 or M2k vs LCA we could have some discussion. But Harrier is completely wrong example to use.

Also, Harrier family has total 4-5 designs with 3 different wing designs and 2 operational designs. After the original prototype Kestral, the Gen 1 (GR1/3 or AV8A) had extensively redesigned airframe and slightly bigger wings. And the Gen 2 (GR5-9/AV8B) has completely new and bigger wing and a lot of composites used in the airframe and 2 more wing pylons and outrigger wheel moves inboard from the wingtip.

[JayS]

Please show if you can, a reference saying Harrier's outboard pylons were *designed only for CCM* of the 1970's era, but could easily take not only new CCM but two AAM on the same pylon without redesign. That would be a fact showing your POV is correct.

Leaving all the factual knowledge aside and without having any knowledge about any aircraft whatsoever, just by knowing how the structural design methodology has evolved over last 50yrs, one can argue that the Harrier was over-designed for given load. That is with the 1960's methodology it was designed say for 100kg, but since the design methodology was less mature, the design actually was more than necessary. Later with improved methodology the OEM could certify the same pylons for higher loads cutting down on the conservatism in the initial design. Now the same pylon is certified to carry say 200kg load without any need for redesign. I have seen such correction in methodology for structural design personally in one of our own product. And I know other such examples from Aerospace industry, both in Metals and composites. You know how F15 seems to have never ending airframe life..? Because they were over designed. Would the designer over designed the aircrafts so much that they can have 3 or 4 times intended life at the height of cold war, if they knew with 99% confidence that they are over designing..?? Obviously not.

Nowhere have I said that Sea Harrier outboard wingpoints were designed only for AAMs. Nor was it over-designed as per your note. The designers knew precisely what they were doing.

Just to be clear, I do not say they overdesigned it as a fact. I am saying, I can make perfectly logical engineering arguments to say they might have overdesigned the pylons, which you cannot refute as implausible unless you show me factual reference that they intentionally kept margin. Thus we should not infer from limited available information that they deliberately kept a margin for future growth as it is debatable.

As such considering that the pylons were anyway designed for much bulkier bombs or rocket pods, the question of keeping margin for future AAM is moot.

[vina]

Awwright. This thread has been wrecked by random trolling. Give it a quick 72 and start a fresh one.

[Marten]

Let us wait for the FOC news -- that will fill up pages on pages with non-informative posts such as this.

[Dileep]

The story of gun vibration is quite interesting you see..

Like any mechanical structure that is somewhat flexible, the airframe will dampen the vibrations to some extent as the waves traverse the structure. So, the vibration encountered by things close to the gun mount will be higher. Some stuff that is close to the tail may not even feel it among the general vibration spectrum. So, it is conceivable that the vibration seen by the LRUs will vary, depending upon where they are mounted. There is likely be a computer model that predicts the vibration spectrum at any given location.

All the LRUs within the hazard zone should be qualified for the projected vibration profile obviously. If an LRU can't take the vibration, it may even be moved to a quieter location as part of the design iteration.

Marten, I am still sticking to my prediction on FoC date.

[JayS]

MiG-21 initially used K-13, then R-60, then Magic-1/2, then R-73 & R-77. When K-13 was the "latest" missile, no one knew in future R-77 would be an option. Yet for all these evolutions, No structural design or build changes required.

Only in case of Tejas is the constraint that outer hardpoint was designed around R-60 and could take nothing else without re-design.

tsarkar saar,

Same story with MiG21. See the armament details for various MiG21 cersions:
https://en.wikipedia.org/wiki/List_of_M ... s#Armament

The outboard pylon, right from the onset is designed to take maximum of a 490 ltr EFT that almost 400kg. Along with 250kg Bombs, 250+kg rocket pods and so on. Obviously it could easily accommodate any and every change in the AAM missile evolution. Till date it never ever had to exceed the designed load by even 1kg. So again there is no question of having any margin for growth for AAM. MiG-21's example is also not appropriate to consider.

Unlike this, LCA had to accommodate 2.4x increase in weight. Now you may call it a poor foresight from LCA designers. But using Harrier or MiG21 as examples to drive that point home is a terrible idea. I will go through Jags, M2K, MiG29 as well, that you have quoted. I am learning interesting new things. Didn't know earlier MiG-21 versions has only 3 hard points.

[JayS]

The story of gun vibration is quite interesting you see..

Marten, I am still sticking to my prediction on FoC date.

Despite hints dropped by Tejas FB page, Livefist and SJha about good new coming soon..??

[shiv]

try the F-89: http://files.abovetopsecret.com/files/i ... 688517.jpg

Back in those days wingtip tanks were not uncommon. I have 2-3 in my minds eye but memory is fading. The only name I can recall is the BAC Strikemaster which was a dedicated COIN aircraft to take out turdworld tribals.

Oh of course - also our goofy looking Toofani/Ouragan

[rohitvats]

The outboard pylon, right from the onset is designed to take maximum of a 490 ltr EFT that almost 400kg. Along with 250kg Bombs, 250+kg rocket pods and so on. Obviously it could easily accommodate any and every change in the AAM missile evolution. Till date it never ever had to exceed the designed load by even 1kg. So again there is no question of having any margin for growth for AAM. MiG-21's example is also not appropriate to consider.

Unlike this, LCA had to accommodate 2.4x increase in weight. Now you may call it a poor foresight from LCA designers. But using Harrier or MiG21 as examples to drive that point home is a terrible idea. I will go through Jags, M2K, MiG-29 as well, that you have quoted. I am learning interesting new things. Didn't know earlier MiG-21 versions has only 3 hard points.

JayS - If others designed their outer pylons to carry some in-service load (beyond only the short-range AAM), why did we not do that in case of LCA? Forget margins for anything, that pylon did not have capacity to host anything than R-60. Was such a limitation a trade-off between some aspect of wing/air-frame designing+manufacturing? You'd know the answer.

Mirage-2000 outer pylon can take 300 kg load while Mig-29M has 500 kg capacity. I'm willing to be corrected but both carry only AAMs. This load capacity is much more than in-service CCMs that these types could carry when they entered service. So, someone made provision for carrying higher-payloads from word go.

If it is poor foresight, that is one very serious fore-sight.

[Cain Marko]

The outboard pylon, right from the onset is designed to take maximum of a 490 ltr EFT that almost 400kg. Along with 250kg Bombs, 250+kg rocket pods and so on. Obviously it could easily accommodate any and every change in the AAM missile evolution. Till date it never ever had to exceed the designed load by even 1kg. So again there is no question of having any margin for growth for AAM. MiG-21's example is also not appropriate to consider.

Unlike this, LCA had to accommodate 2.4x increase in weight. Now you may call it a poor foresight from LCA designers. But using Harrier or MiG21 as examples to drive that point home is a terrible idea. I will go through Jags, M2K, MiG-29 as well, that you have quoted. I am learning interesting new things. Didn't know earlier MiG-21 versions has only 3 hard points.

JayS - If others designed their outer pylons to carry some in-service load (beyond only the short-range AAM), why did we not do that in case of LCA? Forget margins for anything, that pylon did not have capacity to host anything than R-60. Was such a limitation a trade-off between some aspect of wing/air-frame designing+manufacturing? You'd know the answer.

Mirage-2000 outer pylon can take 300 kg load while Mig-29M has 500 kg capacity. I'm willing to be corrected but both carry only AAMs. This load capacity is much more than in-service CCMs that these types could carry when they entered service. So, someone made provision for carrying higher-payloads from word go.

If it is poor foresight, that is one very serious fore-sight.

THIS is the point....

[Cain Marko]

THIS is the point....unable to delete double post....

[shiv]

Pardonnez mois as they say in Botswana. I am no engineer - only a man in need of dental attention, but all this pylon weight limit is linked to the number of Gs the plane is allowed to fly carrying that weight.

This Google books page describes the limitations of the MiG 21 airframe. So it seems to me that a bland statement saying that a plane can carry X kg on a pylon needs to be qualified with the number of Gs it is allowed to pull. If a plane can carry 60 kg and do 8 G then the same pylon can carry 100 kg and do lesser Gs - maybe 4.8 G depending on other factors as listed in the link above including speed and fuel state.

Any fullset 32 teeth comments?

[JayS]

Pardonnez mois as they say in Botswana. I am no engineer - only a man in need of dental attention, but all this pylon weight limit is linked to the number of Gs the plane is allowed to fly carrying that weight.

This Google books page describes the limitations of the MiG 21 airframe. So it seems to me that a bland statement saying that a plane can carry X kg on a pylon needs to be qualified with the number of Gs it is allowed to pull. If a plane can carry 60 kg and do 8 G then the same pylon can carry 100 kg and do lesser Gs - maybe 4.8 G depending on other factors as listed in the link above including speed and fuel state.

Any fullset 32 teeth comments?

G-load specs do matter. Currently here the discussion is for outboard pylons meant for CCM typically, (but not necessarily so always) which are generally rated for full G-load that the Aircraft is certified for. All 4th Gen aircrafts are atleast 7.5G capable and the difference between 7.5G and 9G can be neglected to keep the discussion simple, IMO. There are many more other parameters to which we are not considering anyway.

And example of change in station capacity based on G-load:

[rohitvats]

Great chart.

OT but thanks everyone for great series of posts. Even a BA pass and land-lubber like me learns a few things!

[vina]

Didn't know earlier MiG-21 versions has only 3 hard points.

I had mentioned earlier that Mig -21 Bissun is NOT Mig 21 Kissun . Bissun Not = Kissun.

But the more TELLING story, I had already written about this multiple times is not that we inducted close to 1200 Mig 21s in India , but rather the critical problems of the Mig 21 , short range and endurance due to fuel tank layout, resulting in the forward fuel tank being unusable totally because it would make the plane statically unstable, fuel flow problems in hard manoeuvring causing flame outs, leading to a horrendous crash rate and loss of lives.. none of that got FIXED .

If ANY in service plane could have benefitted from just plain pitch axis stability augmentation , even very rudimentary one and made a world of difference in range and persistence, and indeed SAVED LIVES, it was in the Mig 21.

Now show me ONE study by the IAF as one of the largest operator on this to put in artificial stability and make the fuel fully useable in the Mig 21. All the IAF did was sing Hosannas to it or whine and effectively we had an UNTOUCHED Mig 21 variants as imported from Russia. I had also written the exact same thing on this when Abhibushan /TkSen was active on this board.

An upgrade in the mid 70s of the Mig 21 with stability augmentation and a composite wing, coming into service in mid 1980s would have meant an extremely competent plane that could have lasted until 2020 in numbers. But no, we had to go hunt for Mirage 2000, Mig 29, Mig 23 (which frankly was a horror in IAF service)..and whatever.

The Chinese atleast played extensively with their Mig 21, including ones with totally different wings and fuel layouts. Full marks to them on that.

[tsarkar]

What are the expectations from the smallest bird in the world? - Should it be able to carry loads equal to Su-30.

The now retired Sea Harrier was a 6374 kg bird carrying 3630 kg payload as is the Tejas a 6560 kg bird carrying 3500 kg payload as per ADA here

http://www.tejas.gov.in/ADA-Tejas%20Brochure-2015.pdf

So rest assured, expectations were very realistic.

It is another myth floating here that Tejas specifications were unrealistic.

Whatever ASR's have come out in CAG Report, like 3000 hours TTL is equal to MiG-21 and lower than F-16 8000 hours TTL.

For now, half ready non-tested and non-touched foreign products are far better than half ready but extensive tested local products.

I have written extensively on the difference between development testing and user acceptance testing, so I'm not repeating that. Its up to members to believe what they want.

Coming to hardpoint design, the outcome required is optimally carrying 3500 kg.

Whether you design two strong hardpoints and thereafter add multiple ejector racks like Sea Harrier or this Saudi F-15 or ones like Tejas are just ways of achieving the required outcome.



I understand JayS PoV of hardpoint at the outer end requiring extra structural stressing, but frankly, where the hardpoint is situated is immaterial to the user. Its the load carrying ability that matters.

Keeping a hardpoint restricted to 43.5 kg is actually not factoring obsolescence and constricting the user, and not user perfidy. Replacing obsolete missiles is not fickle behavior.

[Marten]

Tsarkar Sir, please do not get offended with my questions. Trying to learn.

Does the Sea Harrier have similar STR , ITR requirements as the Tejas? What about comparisons with similar platforms such as the Gripen - - why do you think users of that platform will be OK with its current load capacity? And finally, do you think the ASQR for the LCA mandated a certain number of hard points or the minimum load out?

ADA failed imvho in soliciting requirements from the user in terms of understanding what AAMs were being or would be incorporated over the life of the aircraft.
PS: If the wingtip didn't matter, they wasted three to five years overall instead of simply working on multiejector racks. Why? Would be happy to learn.

[vina]

PS: If the wingtip didn't matter, they wasted three to five years overall instead of simply working on multiejector racks. Why? Would be happy to learn.

The bulk of the delay in the LCA is due to radar (the failed indigenous MMR). The "problem" with the LCA is that it got into the 100% "indigenous" fetish, from Radar, to Engines to everything. But that is the nature of the beast. We as a country has a "100% indigenous fetish". We will point out that the LCA/Arjun is 60% /50% whatever "only" indigenous, and hence we should "import", but a 100% imported and screwdriver giried SU-30 and T-90 is miraculously "fully indigenous" .

The other big problem is PISS poor program management and decision making. Now decision making by Govt / Mantris and assorted Baboons is NEVER a good way to do anything, more so in a complex stuff like the LCA, and in addition, we had a basically clueless IAF , with absolutely no experience in any of this , but with massive outsize ego and a huge supercilious air (with nose in the sky) and prone to throwing weight and strutting around and more importantly ZERO stake in this and therefore benign neglect. For the weaponisation fiasco, the time to revise specs was BEFORE FSED phase was happening after the TD phase was going on.

It is not that the IAF was unjustified in asking for the R-73, it was absolutely necessary. The trouble is that the IAF guys attached to the LCA's PMO (program management office), couldnt care less, and tell them.. err. boys, the production version weapon fit is not what we gave earlier, and we are therefore giving out the specs for that far ahead so that this can have been incorporated in the first iteration itself . Instead they rather sat around twiddling with their thumbs in their backsides and then raised a engineering change request late , after the design was already done,necessiting a second iteration with additional stiffening with layers of carbon fibre. The change itself would have taken very little time to do, but qualifying and certifying it would have taken the bulk of the time.

That apart, the wild goose chase of qualifying the R73 itself on the LCA was a wasted effort in my opinion. We are going with an Elta Radar and Python + Derby package. The R-73 makers basically showed us the birdie and told us to take walk when we said, give us the interface so that we can mate the legacy R-73 (I assume this would be the earlier non Mil Std one) , and so we would have had to painstaking analyse the missile communication protocol on an analyser ,hack it and then mate it with the Mission Computer (and i would say PROBABLY with reduced functionality as well than with say a Mig 21 Bison or Mig 29 or Su-30) . This again is a minimum one year effort.

Ultimately it was the quality of decision making by the IAF + Baboon & Mantri combo on critical calls on radar and weapons that you need to hang the bulk of the delay on. If you see the program, the "technical development " in airframe delays have been very small. Now the IAF + Baboon & Mantri are sacrosanct and cannot be called out and bashed . They will kick you hard back in the gonads. The ADA are the poor chumps who can't kick you back, so you dump on them with random stuff.

And why was qualifying an R-73 even needed? It would indeed be worth an attempt of the IAF to tell the French that they don't want the Magic /Mica on the Rafale and M2K but rather want the R-73 and R-77 instead (the non Mil Std versions) . I am not sure the French would be very amused with that suggestion.

[Cain Marko]

Wrt recessed carriage on mk2, perhaps the Mirage 2000 would serve as a better way forward with 4 Aams carried around the fuselage, this way even a smallish airframe can fairly bristle with Aams and still leave heavy stations free....




Prefer this to the multiple rack solution tbh

[shiv]

I need to ask a question. If a pylon is designed for 70 kg because it is an outboard pylon that will tend to bend and break off the wing at high G-forces if 100 kgs are loaded - what "future weapons" has it been designed for.

This is a "Have you stopped beating your wife" question. If a pylon can take only 70 kg, it can take only 70 kg. Future weapons will have to be designed to fit loads that do not exceed 70kg. For example the American copy of the Chinese J-20 (called the F-35) needed to have new weapons designed for its internal bay - namely the SDB.

So what is stopping India from developing a 70 kg close combat missile?

[brar_w]

I need to ask a question. If a pylon is designed for 70 kg because it is an outboard pylon that will tend to bend and break off the wing at high G-forces if 100 kgs are loaded - what "future weapons" has it been designed for.

This is a "Have you stopped beating your wife" question. If a pylon can take only 70 kg, it can take only 70 kg. Future weapons will have to be designed to fit loads that do not exceed 70kg. For example the American copy of the Chinese J-20 (called the F-35) needed to have new weapons designed for its internal bay - namely the SDB.

So what is stopping India from developing a 70 kg close combat missile?

The F-35's internal stations 4 and 8 are designed for 2500 lb / 1100 kg and the air to air stations 5 and 7 for 350 lb/158 kg carriage. The ability to carry the the 2000 lb bomb internally was a programmatic requirement and a Key Performance Parameter from the very start of the developmental program for two of the three F-35 variants. The USAF needed the 2000 lb bomb so that it could retire the F-117 and the navy demanded it as a pre condition to for it to stay in the program. .

The SDB pre-program risk reduction, prototyping and testing pre-dates the F-35 EMD award and its basic mandate was to design an accurate, high loadout weapon for external and internal carriage on all aircraft including manned, unmanned, strike or multi-role, long range bombers or short range fighters. It was not specific to the F-35 program. The SDB II is a mere continuation of the SDB program which expands the mission to all weather moving targets and CAS. Even for it the objective integration platform is the F-15E Strike Eagle.

In case of the SSB (SDB S&T effort) the technologies in miniaturization and high accuracy enabled greater magazine depth whether that is for internal carriage or external. Israel and even India is making use of this leap in the ability to develop compact weapons that do not loose effectiveness compared to larger weapons of a decade or more ago. Same will happen with A2A missiles because of the two issues and technologies I mentioned before..One is the proliferation of future decoys drone swarms etc forcing a very high # target discrimination challenge and second is the advancements in missile components, seeker technology, hit to kill accuracy allowing the warheads to shrink.

This will let you trade larger diameter, longer weapons for more smaller ones (not totally but as a complementary capability much like CCMs are today) in situations where you can't use the range advantage of larger weapons (you can't kill something from 80 km if you can't fix it at 80 km for example). These will be complementary weapons to large diameter AAMs i.e. very fast, lightweight compact A2A missiles that get MRAAM class range on account of smaller (or no) warheads. USAF has a SACM program and Raytheon is funded to deliver test missiles in a few years. Lockheed has completed its design for CUDA and is currently shopping for a seeker. Israel plans something around the totally H2K (no warhead) Stunner.

[geeth]

Guys,

Some really new gyan I am learning from this thread...

Because, all this while I was thinking that it is the structural strength of the wing that determines the weight that can be slung at the tip according to flight conditions and not the otherway round! At the most the designers would check whether the to-be-used missile conforms to the design limits. Otherwise, why would the LCA fly with a dummy missile during test flights? (So that the wing deflection is not too much affecting the aerodynamics of wing in that particular weight distribution?)

IMO even if a situation arises wherein a heavier wingtip missile has to be used, they still can do it by slinging lighter loads in the inner pylons. Actually the permutations and combinations are many if you consider the fuel weight at various times of flight. I am sure the designer considers all these.

[shiv]

IMO even if a situation arises wherein a heavier wingtip missile has to be used, they still can do it by slinging lighter loads in the inner pylons. Actually the permutations and combinations are many if you consider the fuel weight at various times of flight. I am sure the designer considers all these.

Hmmmmmm - interesting point.

[ramana]

tsarkar, Thanks for your response. I know you don't like to suffer fools but please for sake of harmony do so.
Madrasa Math (MM)

vina, please stop using Lahori Logic (LL) and words like that as it takes away from the content of your posts. Your comments on Mig 21 fuel tank layout and static stability should have been written as Aeronautics Journal paper.

Geeth, its very clear the specs of the LCA had some serious gaps to say the least. Those are overcome now. Lets await FOC.

What all this shows is ADA did not do a comprehensive trade study about the R-73 and just went and fixed the wing. Which turned out good as now its a more capable aircraft. Also need to recall there was a TD and then came the fighter plane requirements. TD had R-60 and 23 mm Gsh and a whole bunch of ordnance.


Dileep, You are right packages near the source of shock and vibration see higher environments than those far away. So relocation is an option but wiring harness could be a bear. Most likely these are made on 3-D form boards and quite complex with right amount of twist and connectors.

Shiv, keep asking questions as all are learning.


I see you are looking at your Observer books!!!

[JayS]

Sea Harrier initially used Matra Magic 1, then upgraded to Magic 2 and finally Derby. 8222 pod was added. There were plans for Litening, Paveway, Griffin, Harpoon integration that was dropped since the aircraft was to be retired in the next 10 years. No structural design or build changes required.

MiG-21 initially used K-13, then R-60, then Magic-1/2, then R-73 & R-77. When K-13 was the "latest" missile, no one knew in future R-77 would be an option. Yet for all these evolutions, No structural design or build changes required.

Jaguar is getting new weapons every 5 years. HSLD, CBU-105, Harpoon, etc. No structural design or build changes required.

MiG-29 9.12 too carried R-60 in its outer pylons. The outer pylons were designed to carry only AAMs. Yet when R-73E became available, No structural design or build changes required.

Mirage 2000 was designed around Matra BGL, took Griffin & Paveway & Crystal Maze. Magic in outer pylons replaced with heavier MICA. No structural design or build changes required.

[/quote]

Just like Harrier and MiG-21, the jaguar is also designed right from the outset to carry 1000lbs bombs on its outermost pylons. So no wonder there if it could take up any AAM without any redesign necessary.



Interesting info on MiG-29 from a book called Famous Russian Aircrafts - MiG29. R60 and R73 were simultaneously present on the very first version 9.12. And in the A2G mode the 9.12 could take at least 250kg bombs on the outermost pylons if not more.



Mirage 2000 can carry 230kg or 300kg weight on the outermost pylon, depending on which source you wanna believe, lets say 230kg to be on the conservative side (Below picture shows M2K can carry F4 rocket launchers on the outboard pylons, but I cannot find any picture showing such arrangement so I am not too sure about that one):


In summary, apart from Mirage 2000 (which I am not sure about), All other aircrafts quoted above were designed for larger payloads right from the outset. So there is no question of designers having foresight and keeping deliberate margins for AAM weight growth in future.

[Cybaru]

F35C and AIM9X missile snafu.

The U.S. Navy variant experienced an undisclosed amount of oscillation or turbulence during flight trials with the AIM-9X in December 2015..
..
Engineers have already produced an enhanced outer wing design, which is now undergoing flight testing. The issue has impacted the timeline for fielding AIM-9X, which is being rolled out for the Navy in Block 3F

Because of a seven-year schedule delay, the fifth-generation F-35 fighter will carry air superiority missiles that are one generation behind missiles on F-18s, which are already carrying the newest AIM-9X Block II and AIM-120D.

LINK