LCA: News & Discussions: 15 August 2017

[NRao]

Trainer length is the same as the MK1

MK2 is longer by 0.5 mts

NLCA is longer by 0.36 mts, from the second source.

[Cybaru]

Iirc same length.

From my memory, it is approximately 0.3 m longer. But I couldn't find any sources to confirm it. Maybe Indranil could confirm with his sources.

If the trainer or naval LCA is indeed longer, then we have some experience and the risk is much reduced for mk2 plug.

[Kartik]

Indranil, I have another question for you- did HAL take up the building of the Fatigue Test Specimen for the Tejas Mk1? As per the CAG report, HAL did not take up the building of the FTS as of Feb 2014, stating they did not have a production standard fuselage as of that date. Now, almost 4 years since then, what is the status of the FTS?

Till they do the accelerated fatigue testing of the production standard FTS fuselage, they won't be able to predict the Total Technial Life for the Tejas Mk1. As a result, ADA has had to obtain a concession, giving the Tejas a 1000 hour life, till they actually conduct the fatigue testing to find out what its actual life is. the ASR specified a TTL of more than 3000 hours.

[Indranil]

I want to say that that the Mk1 trainer is the same length. But when Kartik says something, I sit up and listen.

Kartik, will find out about the STS. But I can't think of a single reason why the life of LCA will be any less than the modern birds.

[Kartik]

I want to say that that the Mk1 trainer is the same length. But when Kartik says something, I sit up and listen.

Kartik, will find out about the STS. But I can't think of a single reason why the life of LCA will be any less than the modern birds.

Thanks IR, but you're the one providing some of the most important info and gyan.

As for the Tejas' TTL, it won't be lower than those of other 4th gen fighters, but it needs to be proven with the accelerated fatigue testing. Till then, the Tejas fighters that the IAF is receiving are given an artificial and temporary 1000 hour structural life certification.

[ramana]

That's OK, as its paper problem.

The HAL Chairman Mr. Raju says Production standard is not there yet.

[Singha]

its time mashallah for a dual astra pylon (inboard) for the Tejas giving it upto 4 astra, 4 python5 and 1 belly tank for the CAP mission.
2 tejas on a CAP hence should be able to break up a typical 4 ship strike pkg with BVR shots and follow with the fairly long ranged python5 later.

or keep the wing tanks (make them supersonic pointy nose) and put 2 such pylons underbelly for 4 Astras there.

also the pylon should be designed and tested for 2 x astra-mk2(dummy for now) and 1 mk1+1mk2 loads also to future proof it

[ashishvikas]

#TejasUpdate #6 | #Tejas will participate in upcoming pan-Indian war games #ExGaganshakthi set 2 go live in March-April. All combat fighters will partake in this Ex set to test #IAF's NCW capabilities, reports @ajitkdubey. #Tejas has already participated in #ExLiveWire
@akananth

https://twitter.com/writetake/status/948388604480446464

Last redflag we went with 4xSu-30 and 4xJags, would be a great learning experience if we sent 4xTejas instead of the Jags next time.

[Indranil]

Kartik,

Trainer: Same length, slightly taller, better CnB allows 26 degree AoA.

STS: no clarity. Let's leave it at that.

[shiv]

Of course when glossy foreign fighter aircraft brochures are printed - the airframe life is always printed as a well established fact even though they may not have completed all the tests needed. Since fighters are flown in risky conditions - any accidents can always be blamed on a foreign air force. But when it's your own - one must be careful. This does not happen with civil aircraft though - I am sure. At least it has not happened yet - need to see what happens when China enters the civil export market..

[ramana]

Actually the fatigue life is predicted value right from design stage. By knowing the stress and comparing to fatigue stress from life of materials used we can get fairly good idea.
What Kartik is asking is if the confirmatory test vehicle is built.

[Kartik]

Trainer length is the same as the MK1

MK2 is longer by 0.5 mts

NLCA is longer by 0.36 mts, from the second source.

the N-LCA is derived from the trainer variant. Which would then seem to imply that the trainer is also 0.36m longer than the single seater AF variant.

[Cybaru]

Kartik,

that meshes well with what you remember as well, the 0.3 meter increase.

[Kartik]

No.45 Squadron's Tejas to participate in Ex Gaganshakti. Big opportunity to showcase its precision in the air to ground strike role. This network centric warfare requires a high speed data link to be on board all the fighters participating in the war games to be able to relay precise targeting and situational awareness info to each other and to ground stations. So is the ODL now operational on these platforms? Or are they simply talking about controlling the force from a single or multiple distributed terminals on the ground?

Tejas to fly in IAF war game Ex Gaganshakti

In a major boost to Make in India in defence sector, the Indian Air Force (IAF) is for the first time planning to deploy the Light Combat Aircraft (LCA) Tejas in its mega pan-India exercise called 'Gaganshakti' in which almost all the combat aircraft of the service will take part in March-April this year.

The LCA Tejas planes have been inducted into the 45 Squadron of the IAF in the Initial Operational Clearance (IOC) configuration and are being readied for carrying out operational roles in the near future.

"A few of the tests have to be done on the LCA which are in the process of being carried out. After these are done, the plan is to deploy the planes in the forthcoming pan-India war games code-named 'Exercise Gaganshakti'," government sources told Mail Today.

This will be a big boost to the Make in India progarmme and will be a big landmark for the indigenous aircraft development project, which is now entering an important phase of getting operational, an IAF official said.

The LCA project approved in 1983 has been marred by delays due to the sanction regime of the United States in the late 1990s and early 2000s and delays on part of laboratories of the DRDO.

However, the programme received a major push from the defence ministry as recently, the defence minister-led Defence Acquisition Council cleared the Rs 48,000 crore project to procure 83 LCA Mk1A from Hindustan Aeronautics Limited and the tender in this regard was issued last week to the public sector firm.

The Gaganshakti exercise is a pan-India war game conducted by the Air Force across its operational commands where the response of the force is checked to the threats faced by it on different fronts.

During the exercise, the IAF will operate its latest acquisitions in a network-centric environment, achieving very high levels of synergy with the Army and the Navy, sources in the Air Force said.

During this exercise, several hundred combat planes including the Su-30MKI, Mirage-2000, Jaguars and MiG 29s would take part and hundreds of missions would be flown with impeccable planning and execution, they said.

The exercise will be based on a scenario that included rapid deployment across the country at all operational Air Force bases.

Meanwhile, defence experts feel that the decision to procure the LCA will reduce the dependence on imports.

The IAF has already placed orders for 20 LCA Mark 1 aircraft which would be more of technology demonstrators but the IAF was more interested in having the LCA Mark 2, which would be a more capable and upgraded version of the indigenous plane in the making for the last over two decades.

The HAL would first deliver the Mark 1 aircraft to the IAF and then would produce the Mark 1A in the interim till the time it is ready with the Mark 2 version.

The project would give a strong push to the indigenous fighter aircraft industry as this would be the first major bulk production order for the plane.

[ramana]

Eagerly await the details of the exercise when it happens. So its multi base, multi plane with threats on multiple fronts.

https://en.wikipedia.org/wiki/List_of_e ... _Air_Force

So Gaganshakti is being conducted after 12 years. Earlier one was in Sep 2006.

[Indranil]

Trainer length is the same as the MK1

MK2 is longer by 0.5 mts

NLCA is longer by 0.36 mts, from the second source.

the N-LCA is derived from the trainer variant. Which would then seem to imply that the trainer is also 0.36m longer than the single seater AF variant.

I think you all are confusing NLCA Mk2 with NLCA. NLCA Mk2 is a full 1.36 mtrs longer than LCA/NLCA/trainer Mk1.

[Cybaru]

There is no NLCA mk2 on the table is there?

[ks_sachin]

Kartik,

Trainer: Same length, slightly taller, better CnB allows 26 degree AoA.

STS: no clarity. Let's leave it at that.

Indranil question:

I was looking your post on the LCA (Tejas does not come easy to the tongue and I prefer acronyms!) from a couple of years ago when there was discussion on AoA. It has been cleared for 22 deg but further envelope expansion was to come about after one of the LSP's would be be fitted with recovery chutes etc. So what is the latest on that unless I have missed something.

Why is the CnB on the trainer better?

Secondly in the above post you have stated that Trainer has achieved 26 deg.

What is the cause of the difference in AoA between the two. I know that the canopy shape is different (and you have alluded to the fact that LCA canopy reshaping will help in drag reduction).

Also if canopy reshaping happens on MK1A can that be incorporated into the MK1 as part of an MLU? If they did know that this was an area for efficiency gain why not incorporate into MK1 itself?

Thanks

BTW - pleasure reading your posts - you have set this old dog on the quest for understanding aerodynamics!!!

Any good resources you recommend?

[srai]

What's the max speed at 24 and 26 deg AoA? (Min speed is at around 200 kmph or below)

[NRao]

There is no NLCA mk2 on the table is there?

Navy has the funds to complete the dev and is expected to be dev, but no plans to induct it.

[shiv]

https://twitter.com/writetake/status/948551891167752194

Anantha Krishnan M
✈‏ @writetake

An observation | A close look at all anti-#Tejas stories in the last couple of months clearly points towards 'one person,' who might well be the so-called 'source.'

[ Note: No Qs to be entertained ]

[JayS]

What's the max speed at 24 and 26 deg AoA? (Min speed is at around 200 kmph or below)

Corner velocity. That is when it pulls highest Gs at lowest speed possible.

Dont expect to find an easy answer for that. But looking at flight envelop of F16, which is available on internet (loook for F16 manual), you can get ballpark figure.

[srai]

https://twitter.com/writetake/status/948551891167752194

Anantha Krishnan M
✈‏ @writetake

An observation | A close look at all anti-#Tejas stories in the last couple of months clearly points towards 'one person,' who might well be the so-called 'source.'

[ Note: No Qs to be entertained ]

That “official” source needs to be named and shamed!

[SSridhar]

That “official” source needs to be named and shamed!

At least here, we should be aware of that source.

[Indranil]

Indranil question:

I was looking your post on the LCA (Tejas does not come easy to the tongue and I prefer acronyms!) from a couple of years ago when there was discussion on AoA. It has been cleared for 22 deg but further envelope expansion was to come about after one of the LSP's would be be fitted with recovery chutes etc. So what is the latest on that unless I have missed something.

Further envelop expansion has been carried out since then. The parachute was deemed unnecessary. The LCA Tejas (AF version) was flown safely to 26 degrees AoA, and so operationally cleared for 24 degrees. All LSPs and SPs can do that. Rumour has it that Ranga and Mao sir sometimes have the limit set to 26 degrees for airshows. I can't corroborate this last statement though.

They intend to eventually fly the prototypes to 28 degrees, paving the way for operational clearance for 26 degrees. However, it is not deemed as a priority right now. Already, the high AoA performance is really good. Recently, they wanted to test auto recovery of the plane at high AoA and very low speeds. I won't reveal the number, but at those speeds, Gripen and Rafale float their canards just in case their FCS fails. This effectively makes the lift generated by the canards go to zero. The C.L. goes behind the C.G. changing those aircrafts into a stable aircraft. LCA does not have that luxury and to make things worse: it has the highest static margin (measure of instability) to start with. Yet, in the tests, they found the the aircraft recovered very easily from that position. So, they went back to tweak the FCS, and will soon test the recovery at even lower speeds .

But hey! These are SDRE scientists. They don't know and care for publicity and marketing. I keep saying this: people here underestimate how good of an FCS Tejas has. It is simple, but VERY ROBUST.

Why is the CnB on the trainer better?

Secondly in the above post you have stated that Trainer has achieved 26 deg.

What is the cause of the difference in AoA between the two. I know that the canopy shape is different (and you have alluded to the fact that LCA canopy reshaping will help in drag reduction).

The trainer was actually flown to 28 degrees AoA and hence operationally cleared for 26 degrees.As an aircraft pulls higher AoA the vertical tail becomes more and more ineffective in providing stability. Instead the designers design the forebody of the fighter to provide stability at these regimes. The trainer has a taller forebody (or deeper keel, whichever way you look at it) which gives it more stability than the AF version.

Also if canopy reshaping happens on MK1A can that be incorporated into the MK1 as part of an MLU? If they did know that this was an area for efficiency gain why not incorporate into MK1 itself?

It will be (is my guess). Here are a few observations though:
1. All these studies have been limited to CFD. They are going for wind tunnel testing now.
2. Mk1A is HAL's baby. AFAIK they are not talking to ADA yet. How much structural and aerodynamic changes will they incorporate? Only HAL knows. But I will say this. In terms of fixed aerodynamics, HAL is far far behind ADA's consortium. Similarly, in term of manufacturing and maintenance, ADA is far far behind HAL. I hope and pray that they talk. There are a whole bunch of aero-optimizations that they can pull into Mk1A.
3. The canopy reshaping was actually found to aid in drag reduction, but decrease AoA performance (IIRC, it increases pitching moment). But there are other ways to make up for that. First, they have found that the CnBeta of the SPs is better than that of the LSPs. The tighter manufacturing tolerances provides better symmetry of the keel. Second, they can add a very small chine to the nose (at the base of the pitot tube). Although it will hardly be visible, it will pin symmetric vortices to the nose. This will aid in stability.

BTW - pleasure reading your posts - you have set this old dog on the quest for understanding aerodynamics!!!

Any good resources you recommend?

Thank you for your kind words. I actually have no formal training and know very little. I just love airplanes from childhood. I am happy that I could enthuse you into my field of passion in even a small way.

I won't recommend a book.What you want to read really depends on your interest. Just go looking for different planes, designers, pilot accounts etc. One thing will lead to another. If you get interested enough to where equations don't bother you, then take up a book or an online course.

Build an aeromodel. Nowadays, with brushless motors, some glue and foam, and a knife you can build your first aeromodel in less than 2 hours. There are many plans available online. No need to build an aerofoil. Just make the upper surface of roughly that shape. Tie it and one end and fly. Or just give it yaw and pitch control. It is a lot of fun. Just build a few before you go though. You will crash a few on the first day Don't worry the battery and the engines mostly survive the crash and can be used for another model.

[shiv]

That “official” source needs to be named and shamed!

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

[Cybaru]

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

Thanks for sharing.... I wonder whose Temple he prays in..

[Karan M]

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

Very subtle.

But he is not an "official source". I suspect Writetake is referring to some other guy.

[JayS]

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

If I read it right, the guy is shameless and naming and shaming won't make any difference to him. But I agree with Karan M here. Looks like AKN is pointing to some "official" source.

[JayS]

Any good resources you recommend?

Let me take liberty to recommend a book or two, even if the question was not directed to me, in case you want to stay in the comfort of your desk.

Anderson's "Intro to Flight" is very a good book to start with. If you want to get past that for more rigor you can go to same author's "Fundamentals of Aerodynamics" and "Aircraft Performance and Design". His books are somewhere between popular mechanics and engineering textbook.

FAA has "Handbooks for pilot" or something like that. That's also good one.

If you are interested in Aircraft design (top level view at aircraft as a system) you can take a look at Daniel Raymers book on Aircraft Design. Another more detailed one is by Jan Roskam but you might find it little boring. Reading Aircraft design book is fun actually.

[Thakur_B]

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

I think writetake is referring to his source. Rajatptoi's been rumoured to be the distributor of sorts to other DDM, but he has a wholesale supplier.

[suryag]

X posting from the IAF thread on HAL capacities



We also have an interview from Sri TS Raju, HAL CMD which was posted earlier here

http://indianexpress.com/article/busine ... g-4944113/

There is not much controversy about the LCA. HAL stands very strongly behind the LCA. We have established the production line capacity of eight aircrafts, the first five of them are already flying and have done more than 600 sorties. They are doing up. and we have kept things in place to produce eight and we are investing Rs 1,331 crore to increase the capacity to 16 deliverable a year. We have also used another concept of contracting the main components of the aircraft such as the front fuselage, centre fuselage, rear fuselage to L&T, WhAM, DTL.

We have placed the orders. If these guys start giving me the required top-quality product, that adds to my deliverables. Now question comes, how much order I have. I have 20 IOC, of which I will provide 11 to IAF by the end of this financial year, and that would leave me with 4 fighters and 4 trainers, and trainers’ SOP we hope can be concluded so that the production run can be there.

As far as the FOC order is concerned, mid-2018 is when FOC is expected to come but we are asking the customer (IAF) to allow us to cut the material. Because if we start now, the aircraft will come after three years. By then, this AON of 83 LCA will be converted into a contract between the IAF and HAL. However, today the facilities are on and the rate at which jigs are created are available, and the purchase orders can be verified and checked.

Few things that are unclear
1. The chhotu assembly line(prod capacity - 3) from Hawk/Kiran line is not counted for in the reply to parliament nor by Shri.TSR. why ? But i should say whoever conceived and implemented this idea in HAL has to be rewarded as they probably saved 400-500 crores
2. He says he will deliver 11 by end of Mar 2018, SP5,9,10 from Chhotu line and 8,11 from big assembly line ? Ignoring the line from where it comes from next year's production should be way greater than 11 ?
3. According to the reply to the parliament 20-FOC are already on order, if IAF is in a hurry to shore up its squadron numbers why not let HAL go ahead with the metal cutting process(or whatever Shri.TSR refers to above), are their doubts on structural integrity(or some mumbo jumbo aviation word) w.r.t Gun firing, A2A refuelling or flight envelope expansion(other items like BVR should probably have no bearing on airframe given carriage tests have already passed ?)

[SSridhar]

At least here, we should be aware of that source.

Arabs would call him Bandit; he's first a Raj but not a king; next a jat but that's not his jati

Shiv, I also believe like a few others that the source being referred to is more an 'internal store'. May be retired. Who has been frequently sniping at Tejas?

[Karan M]

LCA Report in Hindi

https://pbs.twimg.com/media/DSssJIJU0AAgx1d.jpg:large

[JayS]

Few things that are unclear
1. The chhotu assembly line(prod capacity - 3) from Hawk/Kiran line is not counted for in the reply to parliament nor by Shri.TSR. why ? But i should say whoever conceived and implemented this idea in HAL has to be rewarded as they probably saved 400-500 crores
2. He says he will deliver 11 by end of Mar 2018, SP5,9,10 from Chhotu line and 8,11 from big assembly line ? Ignoring the line from where it comes from next year's production should be way greater than 11 ?
3. According to the reply to the parliament 20-FOC are already on order, if IAF is in a hurry to shore up its squadron numbers why not let HAL go ahead with the metal cutting process(or whatever Shri.TSR refers to above), are their doubts on structural integrity(or some mumbo jumbo aviation word) w.r.t Gun firing, A2A refuelling or flight envelope expansion(other items like BVR should probably have no bearing on airframe given carriage tests have already passed ?)

1. Its in Kiran hanger. 2nd line is coming up in Hawk hanger. Not mentioned separately perhaps because its internal HAL effort to get first line to reach 8/yr sooner. Guess they ran out of space in LCA hanger for anything additional. Most probably (my guesstimate) they only have final assembly and equipping there and its not a standalone line (That is, it may not have its own full set sub-assembly jig/fixtures, as equipping stage was the one bottlenecking production rate. So makes sense only to create additional copies of final assembly jig).
2. I suppose next year we should see 8-9 LCA (Given they sort the matter with 4 trainers included in the IOC order). Even with 11 delivered by March end (which is unlikely given how many times dates are pushed ahead) its 7 in year 2017-18. Plan was for 6. So even if only till SP10 delivered, still they are on track.
3. IOC order in 2006, FOC order in 2010. But according to 2015 CAG report the FOC order was to be modified. Its not clear why metal cutting would be held up. Any and every change in airframe for FOC should have been frozen long back. Another example of unrealistic program management perhaps.

[Karan M]

the Image I posted says (for non Hindi speakers):

Basically, SP-7 had an event free flight. 20 LCAs will be handed over in IOC Config. HAL is doing all it can to speed up production via outsourcing etc and IOC to FOC changes entail some 270 modifications and these take time, rework of jigs etc hence the effort. SP-5 will fly soon and airframes till SP-10 are ready and in various stages of production. Soon SP-11 and SP-12 will be on the assembling platform. IAF is setting up a state of the art facility at Sulur for 20 aircraft and the Flying Daggers will shift there once they have enough planes. By mid-2018, HAL will hit its stride and start making around 16 airframes a year. HAL aims to make 20 LCAs a year thereafter. And that will set up a 4.5 Generation aircraft manufacturing ecosystem in India. This is how the 83 aircraft RFP will be made by HAL.

[srai]

^^^
Good to hear about the production facilities building up to 20 in the next two years.

But will the Mk1A be ready for production by then? Will the lines sit idle until Mk1A is ready post 20 Mk.1 FOC?

[JayS]

the Image I posted says (for non Hindi speakers):

Basically, SP-7 had an event free flight. 20 LCAs will be handed over in IOC Config. HAL is doing all it can to speed up production via outsourcing etc and IOC to FOC changes entail some 270 modifications and these take time, rework of jigs etc hence the effort. SP-5 will fly soon and airframes till SP-10 are ready and in various stages of production. Soon SP-11 and SP-12 will be on the assembling platform. IAF is setting up a state of the art facility at Sulur for 20 aircraft and the Flying Daggers will shift there once they have enough planes. By mid-2018, HAL will hit its stride and start making around 16 airframes a year. HAL aims to make 20 LCAs a year thereafter. And that will set up a 4.5 Generation aircraft manufacturing ecosystem in India. This is how the 83 aircraft RFP will be made by HAL.

I am not sure if that date is correct. As per Parrikar, the second line would take 2-2.5yrs to start delivery after its setting up starts. Mid 2019-early 2020 seems to be likely timeframe.

As I expected, due to additional subline, total capacity with two lines should be greater than 16. I think with incoming subassemblies from Tier-1 companies, HAL will hit 25/yr with these two lines.

[Karan M]

That's what the report says in that little box - but as you say, likely overestimate.

[NRao]

^^^
Good to hear about the production facilities building up to 20 in the next two years.

But will the Mk1A be ready for production by then? Will the lines sit idle until Mk1A is ready post 20 Mk.1 FOC?

The *plan* was to upgrade the Mk1 FOC platforms to Mk1A. IF Mk1A is "not ready", then they can continue manufacturing Mk1s and then circle back and upgrade them to Mk1A. Pain, perhaps, but no need to keep the line idle. IMHO.