LCA news and discussion

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natarajanrams
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Re: LCA news and discussion

Postby natarajanrams » 15 Dec 2009 01:19

SaiK wrote:And while GE or EJ expands to 100+kN, while Snecma-Kaveri per 2009 agreement can only do a max 90kN.



Hmmm... Chinese J10 has Al31 which delivers 12500 Kgms thrust. F35 has an engine that delivers 181 KN thrust..

Going by the logic sought to be shown here India will never be allowed to design and manufacture engines on its own. That seems to be motto of the vendor agents here. This thread opens with close down GTRE first for that is the seed that gives the ability to grow..

If your arguments are correct that increased thrust is the minimum for an aircraft to win combat, why did we choose the Mirage 2000 which has far lower thrust than F16 and why the Mirage 2000 is considered to be equal to the F16. An aircraft only needs optimum engine power to get in to combat.. At the moment the current Kaveri engine is more than adequate for a fighter that will base its efficient killing power on BVR missiles. True in CAS and A2G roles thrust is extremely important but we are not building the Tejas in hundreds and plan to build few squadrons of basic variant.

If indeed the max thrust is what is needed the solution is simple. Take the 117S engine and use it on the LCA MK2 version, You have the engine ready now..

Alternatively make LCA Mk2 a twin engine cousin of Tejas and use Two Kaveri engines. As GTRE reports the thrust now is 81 KN and put two engines and you get more than what we need.

You can also use he current Kaveri engine even assuming the earlier figure of 65KN to re-engine the Jaguars, Some bit of modifications will be needed but remember Jaguar is a stable airframe and remains the backbone of our strike forces. Jaguar has a known problem with poor thrust and yet it remains our main strike fighter for more than 3 decades now. No complaints are made here about that and the applicability of Kaveri to a modified kind of Super Jaguar which can also extensively use the Tejas Avionics is not even dreamt. If this were to be china it would have already been flying in squadrons.

A combat capable AJT in the 20 tons category can also be built using Kaveri. It will be cheap but will have the range and fire power. We need not think about small AJTs alone to train. Fire Power, range, ability to deliver good amounts of bombs if needed in combat will all come in plenty and if we add proper radars it can also do BVR and WVR missiles and can easily supplement the regular combat aircraft apart from being a trainer.

Kaveri can also be used to build a UCAV based on the LCRA built years back. That was a good LOW Rcs design and can be modified to make a low observable UCAV.

We now have the engine and we need to improve it and it is a continuing process. What has been achieved and what is available can be used to a lot of uses if only IAF is able to think, dream and perform.

Unfortunately the only incidents in fighter design where IAF has contributed is the unsuccessful HF 24 project and the sucessful SU30MKI project but the later is only a significant modifications of the existing aircraft and not IAF contribution was basically in user requirement. With the exception of integration and possible project conception and management what is IAF role here is not clear.

Simply thinking that only western engines alone would deliver and Kaveri must be killed GTRE must be closed are the kind of things we hear in a forum supposed to promote Indian Defense.

I'm sure would receive that Tejas is too small an airframe and he 117S engine is too big etc but cannot we extend the size of the airframe.. It will only increase out capabilities.

Only in India we have people who want to write against nation building. Paki sites though not credible on tech and info certainly do not have this self destructive attitude..

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Re: LCA news and discussion

Postby Craig Alpert » 15 Dec 2009 01:43

natarajanrams wrote:If indeed the max thrust is what is needed the solution is simple. Take the 117S engine and use it on the LCA MK2 version, You have the engine ready now..

Alternatively make LCA Mk2 a twin engine cousin of Tejas and use Two Kaveri engines. As GTRE reports the thrust now is 81 KN and put two engines and you get more than what we need.

Having an engine READY does NOT EQUAL to an algebra problem where you PLUG AND CHUG numbers into an equation.. There are a lot of factors that go into taking one engine and putting it across multiple air-crafts.. While you humrously mentioned adding 2 engines in the LCA, you conviently forgot that the MkII has a schedule that the would like to meet.. If a second engine is added, then the entire air frame will need to be recertified and that means missing the deadline..
natarajanrams wrote:Simply thinking that only western engines alone would deliver and Kaveri must be killed GTRE must be closed are the kind of things we hear in a forum supposed to promote Indian Defense.

Maybe you didn't happen to browse the different threads that are on this forum.. Clearly noone here is AGAINS'T KAVERI or it's uses in any other products across the service, be it in frigates, uavs, trains, jets, etc.. Try browsing BR firs, before blabbering stuff like that, because last I checked no on on this site was AGAINS'T anything "INDIGENIOUS"
natarajanrams wrote:Only in India we have people who want to write against nation building. Paki sites though not credible on tech and info certainly do not have this self destructive attitude...

HMMM.. maybe becuase ONLY INDIA is a DEMOCRACY??? while PAKISTAN AND CHINA are sole COMMUNISTS..I agree with you wholeheartedly that when it comes to defence matters, Indian babus are always caught napping, but comparing INDIAN'S or BR and INDIAN'S BABU'S are 2 DIFFERENT THINGS...no one has a self destructive attitude against INDIAN companies, all they try to suggest is a change in their Programm Management which will only happen when corruption is done away with!!!!
Last edited by Craig Alpert on 15 Dec 2009 02:42, edited 1 time in total.

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Re: LCA news and discussion

Postby a_kumar » 15 Dec 2009 02:02

Katare wrote:Let me try one more time.......

Design goal given to GTRE - 81kN (GE404 and Kaveri of 1980s)
GTRE delivered in 2009 - 65kN
LCA now needs - 90kN (Ge 414/EJ200)
New GTRE-Snecma promis - 90kN (in four years)

In 2015, Einstiens will figure out Mk2 will need 100kN (otherwise, it would obviously fall out of the sky).. and what can we do besides going with improved GE/EJ!!

Sheesh!! can't help but wonder which bright person signed off on the 90kN for next stage, when the requirement is already at that number.

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Re: LCA news and discussion

Postby Raveen » 15 Dec 2009 02:41

Craig Alpert wrote:
natarajanrams wrote:If indeed the max thrust is what is needed the solution is simple. Take the 117S engine and use it on the LCA MK2 version, You have the engine ready now..

Alternatively make LCA Mk2 a twin engine cousin of Tejas and use Two Kaveri engines. As GTRE reports the thrust now is 81 KN and put two engines and you get more than what we need.

Having an engine READY does NOT EQUAL to an algebra problem where you PLUG AND CHUK numbers into an equation.. There are a lot of factors that go into taking one engine and putting it across multiple air-crafts.. While you humrously mentioned adding 2 engines in the LCA, you conviently forgot that the MkII has a schedule that the would like to meet.. If a second engine is added, then the entire air frame will need to be recertified and that means missing the deadline..
natarajanrams wrote:Simply thinking that only western engines alone would deliver and Kaveri must be killed GTRE must be closed are the kind of things we hear in a forum supposed to promote Indian Defense.

Maybe you didn't happen to browse the different threads that are on this forum.. Clearly noone here is AGAINS'T KAVERI or it's uses in any other products across the service, be it in frigates, uavs, trains, jets, etc.. Try browsing BR firs, before blabbering stuff like that, because last I checked no on on this site was AGAINS'T anything "INDIGENIOUS"
natarajanrams wrote:Only in India we have people who want to write against nation building. Paki sites though not credible on tech and info certainly do not have this self destructive attitude...

HMMM.. maybe becuase ONLY INDIA is a DEMOCRACY??? while PAKISTAN AND CHINA are sole COMMUNISTS..I agree with you wholeheartedly that when it comes to defence matters, Indian babus are always caught napping, but comparing INDIAN'S or BR and INDIAN'S BABU'S are 2 DIFFERENT THINGS...no one has a self destructive attitude against INDIAN companies, all they try to suggest is a change in their Programm Management which will only happen when corruption is done away with!!!!


Sir, why are you shouting?
and I believe you mean 'Plug and Chug'

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Re: LCA news and discussion

Postby Craig Alpert » 15 Dec 2009 02:45

Raveen wrote:Sir, why are you shouting?
and I believe you mean 'Plug and Chug'

Opps, correct you are! I edited thanks!
Not shouting, just letting him hear a piece of my mind..(I guess the CAPS = Shouting? usage needs to be towned down on my end?)

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Re: LCA news and discussion

Postby Katare » 15 Dec 2009 02:50

a_kumar wrote:
Katare wrote:Let me try one more time.......

Design goal given to GTRE - 81kN (GE404 and Kaveri of 1980s)
GTRE delivered in 2009 - 65kN
LCA now needs - 90kN (Ge 414/EJ200)
New GTRE-Snecma promis - 90kN (in four years)

In 2015, Einstiens will figure out Mk2 will need 100kN (otherwise, it would obviously fall out of the sky).. and what can we do besides going with improved GE/EJ!!

Sheesh!! can't help but wonder which bright person signed off on the 90kN for next stage, when the requirement is already at that number.


If I put you in a LCA powered by 65kN Kaveri engine and throw you in front of Su30MKM, F16Blk52 and J10s and than ask you what do you think Einstien? Are you underpowered? What would be your answer? :P

Not in 2015 but around 2020 LCA Mk3 would need 120kN or so in power. Gripen started with 404, current NG version is powered with 414 and next block would most certainly be powered by 414EPE+ @ ~120KN.
Last edited by Katare on 15 Dec 2009 02:55, edited 1 time in total.

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Re: LCA news and discussion

Postby Raveen » 15 Dec 2009 02:51

Craig Alpert wrote:
Raveen wrote:Sir, why are you shouting?
and I believe you mean 'Plug and Chug'

Opps, correct you are! I edited thanks!
Not shouting, just letting him hear a piece of my mind..(I guess the CAPS = Shouting? usage needs to be towned down on my end?)


Yes sir, CAPS = SHOUTING on the interwebs :)

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Re: LCA news and discussion

Postby a_kumar » 15 Dec 2009 04:16

:wink: I will highlight the implied part of the statement, nothing aimed at you sirji!

Katare wrote:
.

Design goal given to GTRE - 81kN (GE404 and Kaveri of 1980s)
GTRE delivered in 2009 - 65kN
LCA now needs - 90kN (Ge 414/EJ200)
New GTRE-Snecma promis - 90kN (in four years)


..........
a_kumar>>
In 2015, Einstiens will figure out Mk2 will actually need 100kN instead of 90kN (otherwise, it would obviously fall out of the sky).. and what can we do besides going with improved GE/EJ!!

Sheesh!! can't help but wonder which bright person signed off on the 90kN for next stage, when the requirement is already at that number. They should be shooting for a future requirement (~100kN or 120kN) instead of aiming for current requirement (90kN)
........
katare>>
If I put you in a LCA powered by 65kN Kaveri engine and throw you in front of Su30MKM, F16Blk52 and J10s and than ask you what do you think Einstien? Are you underpowered? What would be your answer? :P

Not in 2015 but around 2020 LCA Mk3 would need 120kN or so in power. Gripen started with 404, current NG version is powered with 414 and next block would most certainly be powered by 414EPE+ @ ~120KN.

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Re: LCA news and discussion

Postby Gagan » 15 Dec 2009 04:59

I am not an aeronautical engineer, but it seems that a certain design has its limitations.

It is great for people to talk of 100 and 120KN as projected future requirement, but people need to perhaps remember that the airframe has to also be able to sustain that increased thrust. Why do you need that thrust on this airframe? More weapons load?

A still bigger engine => more fuel consumption. The LCA airframe can only carry so much. It is a Light Combat Aircraft in every sense of the word, and that is how the designers and future operators wanted it.

If any future different aircraft project needs a bigger engine with more thrust, that will have different specs than the LCA. So an engine which will suit that new project's requirement will be developed.

I am sure designers were aware of the limitations that people on this forum are realizing in 2009. What happened with the Kaveri is three things, where the trio of GTRE, MIDHANI and the Air Force need to share the blame (GTRE more than anyone else)
1. The airforce changed thrust requirements when the project was well underway.
2. GTRE failed to deliver even the earlier thrust targets set by the air force.
3. MIDHANI, which has lagged behind in providing the innovative materials and alloys that GTRE needed, resulting in several parts being sourced from SNECMA.

Even I can be a know all and advise everyone to take their vitamins daily and exercise regularly, no need for such condescending unsolicited advise.

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Re: LCA news and discussion

Postby Singha » 15 Dec 2009 07:52

other than a fairly astonishing T:W ratio I am not sure what these future high thrust engines will bring in. even the Ge404IN20 sounds adequate to me because Tejas will never in operational use go for a max warload on real missions. 4 x 500lb bombs (1300kg) and 2 missiles(200kg) is what I see it carrying on strike missions. for A2A, 4 AAMs (600kg) + 2 small AAMs(200kg) = 800kg.

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Re: LCA news and discussion

Postby Katare » 15 Dec 2009 08:00

Gagan wrote:I am not an aeronautical engineer, but it seems that a certain design has its limitations.

It is great for people to talk of 100 and 120KN as projected future requirement, but people need to perhaps remember that the airframe has to also be able to sustain that increased thrust. Why do you need that thrust on this airframe? More weapons load?

A still bigger engine => more fuel consumption. The LCA airframe can only carry so much. It is a Light Combat Aircraft in every sense of the word, and that is how the designers and future operators wanted it.

If any future different aircraft project needs a bigger engine with more thrust, that will have different specs than the LCA. So an engine which will suit that new project's requirement will be developed.

I am sure designers were aware of the limitations that people on this forum are realizing in 2009. What happened with the Kaveri is three things, where the trio of GTRE, MIDHANI and the Air Force need to share the blame (GTRE more than anyone else)
1. The airforce changed thrust requirements when the project was well underway.
2. GTRE failed to deliver even the earlier thrust targets set by the air force.
3. MIDHANI, which has lagged behind in providing the innovative materials and alloys that GTRE needed, resulting in several parts being sourced from SNECMA.

Even I can be a know all and advise everyone to take their vitamins daily and exercise regularly, no need for such condescending unsolicited advise.


If you spend some time on google, you would find answers to all your questions. For instance you can check how F16 or Mig 29 have evolved over last 3 decades. you would see that both airframe and engine kept improving every few years. LCA is going through the same cycle although without ever actually getting inducted in an airforce.

IAF changed requirements because LCA was suppose to get in service in 90s not in 2015. The requirements are different in 2015 thant they were in 1990s and they'll be different in 2030. Another reason for increased thrust engine is because ADA/DRDO couldn't meet the design goals for empty weight of LCA. They missed it by at least a ton or two depending on who do you believe.

So GTRE didn't deliver a 81kN engine
ADA over shot LCA's empty weight by ~1000Kg
GTRE has a 65kN engine which may be airworthy if it passes HA tests in Russia
IAF gave a midlife upgrade to ASQR to make LCA a contemporary fighter which now requires ~95kN engine.

So far IAF has no blame to share with GTRE on anything, it never even came close to making its initial design goals. So if you are going to buy a foreign engine why not buy the one that best meets your requirements.

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Re: LCA news and discussion

Postby Katare » 15 Dec 2009 08:07

Singha wrote:other than a fairly astonishing T:W ratio I am not sure what these future high thrust engines will bring in. even the Ge404IN20 sounds adequate to me because Tejas will never in operational use go for a max warload on real missions. 4 x 500lb bombs (1300kg) and 2 missiles(200kg) is what I see it carrying on strike missions. for A2A, 4 AAMs (600kg) + 2 small AAMs(200kg) = 800kg.


With IN20 engine it failed or faired poorly in sea level testing last year. So obviously the current 85Kn engine doesn't fully meet the need.

I do not know how the future requirements (RMA) would evolve but historically almost always they included a more powerful engine with better fuel efficiency.

I would much rather let IAF decide the load outs for CAP/Strike and SEAD missions.

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Re: LCA news and discussion

Postby Kailash » 15 Dec 2009 08:11

Singha wrote:other than a fairly astonishing T:W ratio I am not sure what these future high thrust engines will bring in.


IAF has been stating the lack of thrust as the main reason for not accepting the LCA. This is the whole premise for a Mk-2.

What if the actual reason was the ready availability of import options? Now with the dwindling number and the increased threat from the east, even if the MRCA comes in really fast, numbers will be low for quite some years. Naturally, they are opening up to see the indigenous option.

Having said that, LCA's success depends on a quick ramp up of mk-1 production, testing to FOC, prove it is a very capable craft, easy to maintain etc. This will be perfect time for the DRDO/HAL to push the idea of more mk-1 with choice of incremental upgrades. This would provide the confidence and the numbers to IAF than waiting on an mk-2.

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Re: LCA news and discussion

Postby Muns » 15 Dec 2009 08:37

PV2 and PV3 participated in arakkonam sea level trials. None of them have the GE 404 IN20 engine which only came in LSP 2 in 2008. Note also the fitting of auxillary intakes to deal with increased air flow during take off has only contributed further.

http://en.wikipedia.org/wiki/HAL_Tejas#GE_F404

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Re: LCA news and discussion

Postby vera_k » 15 Dec 2009 09:22

What type of weapons load will a 65KN Kaveri allow for the LCA?

I wonder if the IAF can't take a leaf out of the nuke strategists bag of tricks and build a lot of 65KN Kaveri powered LCAs to compensate for the weaker engine.

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Re: LCA news and discussion

Postby nachiket » 15 Dec 2009 12:05

vera_k wrote:What type of weapons load will a 65KN Kaveri allow for the LCA?

I wonder if the IAF can't take a leaf out of the nuke strategists bag of tricks and build a lot of 65KN Kaveri powered LCAs to compensate for the weaker engine.


There is no point in discussing a scenario like this. The IAF is never going to fly LCAs with 65 KN engines ever. If the GTRE can improve the Kaveri to provide 95 KN of thrust and make it pass airworthiness tests then it'll be fitted into the mk2. Till then the LCA is going to fly with the GE-F404IN20. If the GTRE doesn't deliver, then the Kaveri programme is is dead as far as the LCA is concerned.

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Re: LCA news and discussion

Postby a_kumar » 15 Dec 2009 12:15

nachiket wrote: If the GTRE can improve the Kaveri to provide 95 KN of thrust and make it pass airworthiness tests then it'll be fitted into the mk2.


Is the 95kN figure extrapolation or quoted somewhere in the media?

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Re: LCA news and discussion

Postby Nihat » 15 Dec 2009 12:21

a_kumar wrote:
nachiket wrote: If the GTRE can improve the Kaveri to provide 95 KN of thrust and make it pass airworthiness tests then it'll be fitted into the mk2.


Is the 95kN figure extrapolation or quoted somewhere in the media?


thats a tad over the line . Even the Kaveri - Smenca is given a target of 91 Kn , if they are able to accomplish 95 Kn then no ones complaining

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Re: LCA news and discussion

Postby merlin » 15 Dec 2009 13:38

IAF changed requirements because LCA was suppose to get in service in 90s not in 2015.


If that is true I would question their sanity considering when the last attempt to design an Indian fighter was made and considering when the project was sanctioned.

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Re: LCA news and discussion

Postby Rahul M » 15 Dec 2009 13:59

Katare wrote:IAF changed requirements because LCA was suppose to get in service in 90s not in 2015. The requirements are different in 2015 thant they were in 1990s .........

that actually points out how how careless and callous IAF was about the LCA.
anyone connected with the program knew that a project starting in 90-91 had no chance of being inducted in the 90's itself, 2005 was the best possible date and 2008-2009 a realistic one. and that includes the IAF's own officers connected with the project.

Fact is IAF never even bothered to set up a realistic ASR for the LCA. it was as if they couldn't care less and were waiting for it to fail.(which is true if we go by how the then IAF chiefs behaved towards the project from the start) in stead of preparing an ASR that should work in 2010 IAF changed ASR in installments, almost once every 5 years.

when the project achieved a modicum of success IAF was caught on the wrong foot. one fine morning in 2002 IIRC IAF decided that it would use the heavier R-73 and not the R-60 and the wings had to be re-designed adding more time to the program. didn't the IAF know that it will not use the R-60 on the LCA ? if I'm not too wide off the mark the R-73 itself was in service with IAF by late 90's. the next change in ASR came in 2005-2006 and it was finally this one that does justice to the LCA and should stay current till 2025 if not more (thanks to a changed mindset in IAF )
The requirements are different in 2015 thant they were in 1990s

that's a ridiculous argument to be frank. no one in their right minds would have expected LCA to be inducted in the 90's. even if we assume that IAF officers were babes in the woods and believed that LCA would be inducted by the squadrons in 2000, an ASR is supposed to stay relevant for at least 15 years from induction, if not more. IOW, LCA according to the the original ASR should have sufficed till 2015 [u]at least without needing an upgrade.[/u]
why then did the IAF had to do not one but two major revisions in ASR before 2007 ?

the LCA Mk1 induction is happening in 2010-2011, where does this 2015 date come from ?
2014 induction date for Mk2 corresponds to a much revised ASR set in 2005-2006 kindly don't bring it into this discussion.
either IAF deliberately prepared an obsolete ASR or was not competent enough to prepare a proper ASR, you decide which one it is !
Another reason for increased thrust engine is because ADA/DRDO couldn't meet the design goals for empty weight of LCA. They missed it by at least a ton or two depending on who do you believe.

that happened mainly due to scope creep, in keeping with IAF's new ASRs.

ADA over shot LCA's empty weight by ~1000Kg

should in stead be written as
ADA prepared a heavier and more capable LCA, just as IAF asked.

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Re: LCA news and discussion

Postby niran » 15 Dec 2009 14:13

Please pardon my ignorance, AFAIK the Wt. of A/C reduces as production number increases.

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Re: LCA news and discussion

Postby ArmenT » 15 Dec 2009 14:25

ajay pratap wrote:Please pardon my ignorance, AFAIK the Wt. of A/C reduces as production number increases.

Not if history is any indicator for the future. For most aircraft models, the newer production models are usually heavier than older ones. Reason is because airforces want to pack more capabilities into their aircraft (better radar, better avionics, more fuel loads for more range etc.) This upgrade usually offsets any weight savings that are gained by better manufacturing techniques, lighter materials etc. If you look at the past, most aircraft produced since WW-II has become heavier as production number increased.

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Re: LCA news and discussion

Postby niran » 15 Dec 2009 14:33

nah, was talking about the same model or as the geeks say batch,
as production number rises manufacturers learn to cut down on excess
fat and the resultant Wt. goes down.
have read someplace that F16 Wt. went down as Numbers increased
to the tune of 350kgs.

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Re: LCA news and discussion

Postby Gaur » 15 Dec 2009 14:46

vina wrote:Bottomline - Dont worry, Have Curry! The IOC standard envelope , both in weapons delivery and flight envelope is done

How could LCA complete its weapons delivery envelope without a radar?

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Re: LCA news and discussion

Postby nrshah » 15 Dec 2009 14:53

Gaur wrote:
vina wrote:Bottomline - Dont worry, Have Curry! The IOC standard envelope , both in weapons delivery and flight envelope is done

How could LCA complete its weapons delivery envelope without a radar?



How sure are we of radar not being intergrated except that there is not news to the effect. It was supposed to be done by march. we also had lot of weapon delivery testing which as u rightly mentioned would require radar. Doesn't it in itself testimony of radar being integrated..

just my 2 paise

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Re: LCA news and discussion

Postby tsarkar » 15 Dec 2009 15:36

Rahul, my understanding of typical ASR’s is that they usually describe requirements and not specifications. So a typical requirement might be “single engine fighter” “radius 500 km loiter time 30 mins carrying 4000 kg” “landing with 1000 kg unexpended ordnance” etc.

I havent seen the LCA ASR, however ASR usually never specifies things like empty weight since empty weight by itself doesn’t mean a damn as long as requirements are fulfilled. However when higher empty weight cuts the payload requirement, then we need the extra thrust to ensure the payload requirement 4000 kg is fulfilled. The thrust specifications are not defined, but derived, fom requirements like payload, speed, rate of climb, range, etc.

The original ~80 kN requirement was for an airframe weighing 5500 kg. The airframe after best trimming efforts weighs 6500 kg. The thrust increase was a natural consequence to the weight increase to allow the aircraft carry original design spec payload of 4000 kg.

To the best of my knowledge (and others may correct me here), I don’t think IAF added ANY requirements over & above the original ones that lead to the weight increase.

I agree with you on the R-60 that was obsolete in the early 90’s and not having the foresight to stress the outer wing hardpoints for heavier missiles. Another inefficiency, in my view, was having a 23 mm belly cannon similar to MiG 21 occupying space for a hardpoint instead of choosing a SU-30/MiG-29 type upper fuselage/wing root 30 mm cannon. I would like to understand why IAF didn’t bother to add beyond MiG-21 specs and why ADA didn’t bother to point out available improvements.

We keep hearing IAF changed requirements, but to the best of my knowledge, other than engine thrust and the hardpoint stressing, there isn’t any anything else that’s changed. However stressing hardpoints won’t increase weight by a ton.

Having said that, it is a potent fighter even today. Even with Litening and IN20 engine and NO radar, it offers strike capabilities similar to Jaguar/MiG27 that too don’t have radars and a quantum shift from ~ 125 Bison ~ 55 Bis ~ 60 M models that urgently need replacement.

The Kukhri/Kora class corvettes don’t have any major Anti Aircraft or Anti Submarine capabilities, still the large number of eight ships were built to mature the shipyards and the Anti Surface capabilities are good enough for the threats faced throughout the ship’s lives.

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Re: LCA news and discussion

Postby Rahul M » 15 Dec 2009 15:58

Rahul, my understanding of typical ASR’s is that they usually describe requirements and not specifications.

ts sir, it's the change in requirements that I'm talking about as scope creep.
these are the new ones :
>> OBOGS
>> full internal EW suite
>> change in avionics architecture to a more capable and robust one
>> ODL (I'm not sure if this has been already incorporated or not)
+ the wing modification, all added to the weight of the LCA. it might not have mattered for a larger and heavier fighter but for a small aircraft this is a significant weight increase. after all, the avionics and other packages weigh the same whether it is the LCA or the MKI !

so of course IAF never specified empty weights and such, it is not their job and I didn't mean that anyway. they revised the requirements as in ASR which led to a consequent increase in weight.

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Re: LCA news and discussion

Postby vina » 15 Dec 2009 16:26

>> OBOGS
>> full internal EW suite
>> change in avionics architecture to a more capable and robust one
>> ODL (I'm not sure if this has been already incorporated or not)


In addition, In flight refueling and AESA. AND I am willing to take a huge bet on this, though this will probably NOT be acknowledged for a long long time.. a bump up in internal fuel from 2300kg to close to 3000kg . Why do I think that ?. I think it is because I think the old LCA was designed with a 30% fuel fraction (2300 int fuel + 1250 50% ext fuel ) / (5500 empty wt +4000 payload +2300 fuel)

If you want the LCA to have sufficient legs (range and loiter), you need the 30% fuel fraction. So work backwards and you will come to close to 3000kg internal fuel number. That tiny airframe is really "packed" to the brim as it is.

Going by specs, the LCA MK II will be right there in terms of specs with the Gripen NG. Only that it will be around 500 to 700 kg lighter (due to composites?)

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Re: LCA news and discussion

Postby Kakarat » 15 Dec 2009 17:55

LCA-Tejas has completed 1266 Test Flights successfully. (12-Dec-09).


LCA has completed 1266 Test Flights successfully
(TD1-233,TD2-305,PV1-236,PV2-129,PV3-189,LSP1-54,LSP2-119,PV5-1).
236th flight of Tejas PV1 occurred on 11th Dec 09.
119th flight of Tejas LSP2 occurred on 11th Dec 09.

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Re: LCA news and discussion

Postby Philip » 15 Dec 2009 18:25

There's famous saying,"cut your coat according to your cloth".The LCA programme and all the stakeholders should keep that firmly as its motto.The aircraft was always meant to be a "light" multi-role fighter,available in large affordable numbers.Let us perfect it as such and leave more arduous and strenuous roles for the heavyweights.If it is used for point defence of air bases and key defence/economic installations in the interceptor role,much as the MIG-21 is being used,but with extra punch in terms of missile power and endurance,it will have served its purpose.It could also assist in close-support in a secondary role.It should be the primary replacement in numbers for the MIG-21s and better than the MIG-21 Bison and the Paki J-10 which Pak is going to acquire with about 150.Keeping that objective in mind,and staing focussed,it is eminently possible to perfect Mk-2 which will give the aircraft the extra thust required and keep it relevant for another decade+ upto 2025.

Beyond that time,the developments in aerospace,which are the most rapid,especially that of UCAVs,will bear upon the planning of all the major air forces.I've said before that given the tech knowledge obtained from the LCA programme,the next immediate project for the DRDO/ADE/IAF should be a stealthy UCAV of LCA size.An unmanned version of the venerable Chetak/Allouette is being developed for the IN,why not an unmanned (flying wing) version of the LCA? In the US,the naval UCAV ,which is also around the same size as the LCA,will be aboard a carrier by 2015 and similarly a stealthy naval UCAV based upon the LCA will be a great asset to have when our new carriers enter service around 2015+.

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Re: LCA news and discussion

Postby Kanson » 15 Dec 2009 18:39

vina wrote: AND I am willing to take a huge bet on this, though this will probably NOT be acknowledged for a long long time.. a bump up in internal fuel from 2300kg to close to 3000kg . Why do I think that ?. I think it is because I think the old LCA was designed with a 30% fuel fraction (2300 int fuel + 1250 50% ext fuel ) / (5500 empty wt +4000 payload +2300 fuel)

If you want the LCA to have sufficient legs (range and loiter), you need the 30% fuel fraction. So work backwards and you will come to close to 3000kg internal fuel number. That tiny airframe is really "packed" to the brim as it is.

I too thinking along this line. LCA need to have sufficient legs

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Re: LCA news and discussion

Postby tsarkar » 15 Dec 2009 19:01

Ummm…

>> OBOGS

Onboard Oxygen Generator replaces the stored oxygen, won’t add major weight. Analogy would be our home Aquaguard replacing the Bisleri jars. Here’s how OBOGS works -
http://www51.honeywell.com/aero/technol ... .html?c=13
http://www.cobham.com/about-cobham/miss ... xygen.aspx

It reduces weight & volume vis-à-vis stored bottles - refer second link - “This system reduces the dependence for heavy, bulky oxygen bottles that add more stress and weight to the aircraft”. Also check out the various fighter specific OBOGS.

We don’t know whether it was a new or old requirement, it was developed around the same time as the CSIO HUD and other systems were developed.

>> full internal EW suite

Full EW suite typically comprises RWR (some sensors & a processor, all internal), MAWS (some sensors & a processor, all internal), Laser Warning Sensors to detect laser proximity fuses and IRST laser rangefinders (some sensors & a processor, all internal), Counter Measure Dispensers (usually chaff & flare cartridges, all internal and probably in Tejas aft fuselage) and jammers that are usually external.

All items, except jammers, are internal, should have been weight budgeted for and cumulatively don’t weigh more than double digit kilos.

Jammers can be internal or external. The Elta 8222 pod weighs 100 kg while the DRDO Tusker pod weighs 230 kg. This is what a typical high end internal jammer is supposed to weigh http://www.es.northropgrumman.com/solut ... LQ135M.pdf

DRDO is supposed to have a JV with Elisra for Project Mayawi integrated EW suite. However this project is ongoing and since Tejas Mk1 doesn’t seem to have any visible MAWS/LWS/internal jammers, this doesn’t account for the 1000 kg differential from design weight.

>> change in avionics architecture to a more capable and robust one

Again, changing the mission computer architecture won’t result in weight gain, only changes in a few LRU boxes. The digital databus was always MIL-STD-1553B.

>> ODL (I'm not sure if this has been already incorporated or not)

Operational Data Link is present in MKI, Sea Harriers, Jaguar, Tejas, Phalcon and probably be fitted to Mirage and MiG-29 during upgrades. It is basically a data card weighing less than a kg using the existing VHF/UHF communication setup for data transfer. I have written a rudimentary description based on my limited understanding here, someone from aviation can elaborate, provided the information is in the public domain.

>> Wing modification

Stressing a hardpoint for higher loads will add few spars and members that require exhaustive time consuming redesign and testing, however won’t add significant weight. The R-60 weighs 65 kg while the R-73 weighs 105 kg.

Point I am making here is that our baby is 6500 kg instead of 5500 kg despite some of our nation’s best minds putting their best efforts on it. That in no way makes the Tejas inferior or ADA’s overall development efforts any less worthy of praise. It is indeed a success story on every count, unlike the assistance received by the Swedes from BAe, GE and Chinese buying/stealing from everywhere.

I fully agree the IAF should have been more involved from day 1 and using the MiG-21 specs initially and rectifying them later was careless.

However it is factually incorrect to state that IAF requirements creep caused weight gain. It was a complex development effort and the 1000 kg weight gain was an unintended consequence. The new engines are towards mitigating the weight gain. Since more power is available, and a hybrid MMR-2032 is being used, AESA was added to the roadmap.

The only casualty was the Kaveri, and its heartening to see long term efforts are taken towards it as well, while delinking its development effort from delaying LCA Mk2.

Vina – we’re discussing the reasons for weight gain from 5500 kg to 6500 kg for the presently flying aircraft, so probably IFR and AESA didnt contribute to it.

This is based on my understanding of the situation, and available information. I would be glad to be corrected.

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Re: LCA news and discussion

Postby Rahul M » 15 Dec 2009 19:26

The LCA programme and all the stakeholders should keep that firmly as its motto.The aircraft was always meant to be a "light" multi-role fighter,available in large affordable numbers.Let us perfect it as such and leave more arduous and strenuous roles for the heavyweights.If it is used for point defence of air bases and key defence/economic installations in the interceptor role,much as the MIG-21 is being used,but with extra punch in terms of missile power and endurance,it will have served its purpose.

with all due respect, the days of missile armed interceptors are long gone. how many missile armed interceptors/point defence fighters are being designed or produced around the world at this moment ? :P
IAF itself uses the mig-21bisons because it already has those. do you think if a 'similar' category aircraft was offered now they will accept it ? :wink:
let's not start preparing for (day before) yesterday's war !

LCA may have been intended as a mig-21 replacement but it offers a capability of quite another order, similar to the m2k, even superior in many aspects.

it would be an effing waste and disgrace not to fully utilize the potential it offers. IAF is doing the very right thing by customizing it so that it really meets head-on the demands of modern aerial warfare, not some half-a*sed ricksaw of a fighter that is cheap in every aspect, cost as well as performance ! :P

==============
2300kg to close to 3000kg

could be. but IMO a more probable explanation IMHO will be 3000 litres of fuel (which is what tejas is supposed to carry) ~ 2300 kg for 'normal' weather in India.
==============

ts sahab, please let me get back to your post.

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Re: LCA news and discussion

Postby Katare » 15 Dec 2009 21:14

Vina's right I think.

Extra 1000kg empty weight meant a larger engine to haul that dead weight. Which would mean more internal fuel to maintain the same range. Higher internal fuel load would mean even bigger engine........

End result- LCA Mk2 was agreed upon by IAF/ADA

Media quotes 90-95-100kN for Mk2

RahulM

It's not IAF or ADA but all of them (including MoD, MoF, CCS, DRDO etc) put togather needs to share the blame. It takes years to get approvals and sanctions for projects, by the time sanctions come in projects are already way behind the schedule. It is not possible to put all of the blame on anyone's door.

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Re: LCA news and discussion

Postby a_kumar » 15 Dec 2009 21:16

Nihat wrote:
thats a tad over the line . Even the Kaveri - Smenca is given a target of 91 Kn , if they are able to accomplish 95 Kn then no ones complaining


I think it is more than that. Feature creep is most common aspect of any project, and many a project become irrelevant if they can't keep up. One cannot be caught unawares and then complain the the product got tanked. Yes, just like we critisize IAF for not being futuristic, we should also blame HAL for the same. HAL/GTRE should know that projects slip and that they should *still* be relevant.

I would think we should have learnt the lesson the hardway. LCA req went up from 81kN to 85kN(??) and now to 90kN. If Kaveri-driven LCA wants to be relevant for next 20 years, isn't it logical that they aim higher than "just meeting current requirement"?

*sarc on*Maybe IAF has written the 90kN on stone!!!*sarc off*
Or maybe HAL says 90kN is the ceiling for LCA's airframe
Or maybe IAF smartly padded the numbers already and they only need 86kN!!!!

Lets discuss in 4 years :)

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Re: LCA news and discussion

Postby tsarkar » 15 Dec 2009 21:20

Take your time, Rahul, and no sahab/sir. My datapoints are based on Ajai’s articles.
http://ajaishukla.blogspot.com/2008/07/ ... ombat.html
http://ajaishukla.blogspot.com/2008/07/ ... es-on.html
There are lots of references on IAF specifications, but not one word on what those specifications are.

Secondly, the intake issue needed resolution. In the article, ADA alternately rubbishes and then grudgingly accepts IAF PoV. What are our engine buff's take on this?

Katare - blaming isnt the solution. When we do something new, issues are bound to crop up. What matters is how we get together to resolve them. And its very easy for me to say this and quite difficult to achieve in practice.

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Re: LCA news and discussion

Postby KrishG » 15 Dec 2009 21:47

What effect will increased wing-loading have on Mk-1 and Mk-2 ? I thought that LCA would depend on it's superior rate-of-climb in combat given it's comparitively inferior instantaneous turn rate due to low wing loading.

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Re: LCA news and discussion

Postby negi » 15 Dec 2009 22:13

On the engine intake redesign it is obvious that IAF's inputs in this regards might have come after debriefing from the test pilots who actually flew the AC , now how optimal the trap doors are when it comes to addressing the issue is for test team to qualify .

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Re: LCA news and discussion

Postby Rahul M » 15 Dec 2009 22:45

It's not IAF or ADA but all of them (including MoD, MoF, CCS, DRDO etc) put togather needs to share the blame. It takes years to get approvals and sanctions for projects, by the time sanctions come in projects are already way behind the schedule. It is not possible to put all of the blame on anyone's door.

agree wholeheartedly. just that, the situation is looking up and now is the time for looking forward.
===============

IMO people are going overboard with this 120-130 kN business. the mig-29 will receive a 7% (i.e about 5.7 kN for each engine) increase in thrust after more than 25 years of service life.
something like 95-100 kN should do nicely even for the Mk2 unless it gains substantial weight, which seems unlikely at the moment.

inferior instantaneous turn rate due to low wing loading.

are you sure of that ? IIRC low wing loading gives superior performance both in ITR and STR. :-?

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Re: LCA news and discussion

Postby Rahul M » 16 Dec 2009 01:12

I was adding the weight increases on LCA component by component and this is what I get.

original ADA data says (still there on the site)

empty wt : 5500 kg
loaded wt : 8500 kg

going by ajai shukla's definition of 'loaded', those 3000 kg corresponds to
7 weapon pylons + 1 sensor pod/EW pod pylon --> 3 X 50 kg for the inner 3 + 5 X 25 kg for the others (approx) = 150 + 125 = 275 kg
Gsh-23-2 + ammo etc - 50 + 25 = 75 kg
2 X R-73 = 210 kg
total = 560 kg + fuel. so at least originally ADA envisaged a fuel load of around 2440 kg

=====
jump to 2008 and ADA displays a board at singapore airshow saying empty wt is 6500 kg, IOW, an increase of 1000 kg over original specs
http://www.flickr.com/photos/20125521@N ... 3/sizes/l/
if so, then by the same calculation above, loaded wt should be 9500 kg.

but, ajai shukla says loaded wt is 10500 kg, 1000 kg more than even the revised estimates !
http://ajaishukla.blogspot.com/2008/07/ ... es-on.html

can we account for this extra weight ? granted, some of it is telemetry and other testing equipment :
The LCA’s designers say that the removal of telemetry instrumentation, which is essential during flight testing, will bring the Tejas’ weight down by as much as 300-400 kilos.

okay, make that 10,100 kg.
they will shave off another 300 odd kg
re-engineering some of the displays and sub-systems within the cockpit will lop off another 300 kilos;


make that 9,800 kg. carrying over the 3000 kg figure, empty weight comes to 6800 kg.
he also says
The IAF accuses the ADA of failing to develop a suitable engine; the ADA retorts that the IAF’s demands for extra combat punch added two tons to the LCA’s original weight of 8 tons.

I guess it's loaded weight he is talking about, which is at ~9.8 t in stead of 8.5 and that there is some element of truth to the idea that IAF's revised ASR's led to at some of that weight increase.

let's try to figure out what those could be :
tsarkar wrote:Ummm…

>> OBOGS

............. I'll go by your explanation that there is no wt increase due to this.

>> full internal EW suite

Full EW suite typically comprises RWR (some sensors & a processor, all internal), MAWS (some sensors & a processor, all internal), Laser Warning Sensors to detect laser proximity fuses and IRST laser rangefinders (some sensors & a processor, all internal), Counter Measure Dispensers (usually chaff & flare cartridges, all internal and probably in Tejas aft fuselage) and jammers that are usually external.

All items, except jammers, are internal, should have been weight budgeted for and cumulatively don’t weigh more than double digit kilos. {AFAIK these were not budgeted for, initial ASR called for external pods only. the equipments have also increased in complexity and weight. pardon me if I don't have the details at the moment. my principal source on this was Jcage/nitin's comments and emails many moons back. I'll try to dig those up/get in touch with him.
combined with the associated wiring, display etc these would weigh around 200-250 kg in total at least. if nothing else, all historical evidence points to this direction, in spite of advancement in electronics, newer gizmo --> more weight than before}


Jammers can be internal or external. The Elta 8222 pod weighs 100 kg while the DRDO Tusker pod weighs 230 kg. This is what a typical high end internal jammer is supposed to weigh http://www.es.northropgrumman.com/solut ... LQ135M.pdf
{I wasn't considering external pods, which aren't counted in empty wt anyway.}


>> Wing modification

Stressing a hardpoint for higher loads will add few spars and members that require exhaustive time consuming redesign and testing, however won’t add significant weight. The R-60 weighs 65 kg while the R-73 weighs 105 kg. {the outboard pylons are designed for 150 kg, given their location, by my understanding these would have needed significant stiffening in order to cater for shearing stress. of course I don't have enough knowledge of aircraft manufacture to put a number to this but I doubt it would be insignificant ! :) }

{another point I forgot to mention earlier was the addition of the dedicated sensor pylon, that alone would have increased weight by a 100 odd kg given the power and other cables etc required in addition to the pylon itself and airframe strengthening. }

However it is factually incorrect to state that IAF requirements creep caused weight gain. It was a complex development effort and the 1000 kg weight gain was an unintended consequence. The new engines are towards mitigating the weight gain. Since more power is available, and a hybrid MMR-2032 is being used..........
{ah, thanks for reminding me. :D that too came out heavier than intended :wink:
and consequently weight had to be readjusted for CG considerations as well.}



all in all, I would hazard a wild guess that there was anything between 300 - 500 kg increase in empty weight due to ASR revision.


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