ADA Tejas (LCA) News and Discussions

[ersakthivel]

To get into any tejas version as future replacement for either GE 404, or 414 kaveri needs to hv corresponding or better Engine thrust to weight than either of them.


If kaveri's thrust increase is accompanied by corresponding weight increase(leading to same or worse engine thrust to weight ratio )

Because mk2 design has already started with GE 414.

No one will put more years into redesigning mk1 with a new kaveri engine ,

which has no improvement in engine TWR over GE 404, (even if kaveri gives 20 % extra thrust , with 20℅ weight increase) is my opinion.

I doubt any one will spend years to redesign tejas , which won't give better combat performance is my opinion.


Where kaveri will score is ,

If it is improved with french help to either match or better GE 404 or GE 414 in Engine TWR, (WTH NO SIGNIFICANT WEIGHT DIFFERENCE)

It will become a replacement engine for mk1, mk1a, mk2 & may become a contender for AMCA too.

Chances are high for this scenario,

But if HAL , GTRE ends up under a visionary like "Air Marshal Matheswaran", who shut down GTRE --SNECMA JV on kaveri, earlier,

with golden words ," GTRE wont learn anything from Snecma jv over kaveri".

Then we will need another Modi to save kaveri a few years down the line.

 

[ersakthivel]

Any company called ," SNECMA" if it suggests to increase kaveri Thrust by 20℅ , by adding 300 KG weight, from its current weight & thrust specs,

as replacement for GE Engine,

Then they are either a ,papad making company or leading us down the doom's alley as far as kaveri is concerned.


No wonder a particular ,"Einsteen" here getting over excited by it.

Because any tejas version fitted with such kaveri wont be competitive, with GE 414 equipped tejas mk2.

I wonder how tejas whose empty weight now 6500 kg , flying with 1000 KG 50/84 KN GE engine,

Will be competitive in 2030 with ,7500 KG empty weight (300 KG for engine+300plus KG for ballast, + miscellaneous weight additions) a 1400 KG kaveri engine giving 60/95 KN thrust.

Because mk2 will fly with with same empty fighter weight & engine thrust with 1100 KG GE414,

To understand that has become an impossible task for one person here.

 

[Kshithij]

"However, if one is suggesting that Kaveri engine should have 20% or even 10% weight penalty over F404 buthave same performanceas F404, then it becomes too much to handle."

I assume you are referring to mk2

I think instead of F404, it should be F414 in the above passage.

Correct ? or wrong?

No, I am saying that the TWR of close to 8 is minimum requirement. F404 has TWR of 7.8 and is the minimum acceptable TWR. So, if the idea is to have Kaveri with lower TWR than F404 by adding weight, it is unacceptable. But, adding another stage to F404 to make it as good as F414 is acceptable.

I am only saying that TWR of engine must be 8. F414 has TWR of 9 and is excellent as a result. But, a small compromise in about 100kg weight from F414 is also acceptable. F414 weigh 1120kg and Kaveri weighing 1220kg and giving same thrust as F414 is also good enough. Being indigenous itself has a significant weightage. and some compromise for achieving it is OK.

However, if the idea is to make 1350kg engine for 98kN thrust or 1200kg engine for 85kN thrust, it is not acceptable. This was being suggested by some people above - to make serious compromise which would make Kaveri engine worse than F404. I am putting a TWR restriction of a minimum 8

 

[ersakthivel]

No, I am saying that the TWR of close to 8 is minimum requirement. F404 has TWR of 7.8 and is the minimum acceptable TWR. So, if the idea is to have Kaveri with lower TWR than F404 by adding weight, it is unacceptable. But, adding another stage to F404 to make it as good as F414 is acceptable.

I am only saying that TWR of engine must be 8. F414 has TWR of 9 and is excellent as a result. But, a small compromise in about 100kg weight from F414 is also acceptable. F414 weigh 1120kg and Kaveri weighing 1220kg and giving same thrust as F414 is also good enough. Being indigenous itself has a significant weightage. and some compromise for achieving it is OK.

However, if the idea is to make 1350kg engine for 98kN thrust or 1200kg engine for 85kN thrust, it is not acceptable. This was being suggested by some people above - to make serious compromise which would make Kaveri engine worse than F404. I am putting a TWR restriction of a minimum 8

What you are saying makes sense,

But when design for mk2 is progressing with GE 414 or engine thrust to weight ratio 9,

Will IAF accept a lower thrust to weight ratio kaveri on mk2?

Mk1 & MK1A have GE 404 .

Mk2 has a bit heavier, but better Engine TWR 1120 KG GE 414,

If we hv to fit 1220 kg engine in mk2,

or

a new developmental version of mk1A, with a new name mk1B

Will IAF prefer it over GE 414 Engined mk2 ?
Because engine cost alone is not a significant fraction in a fighter cost.


If we develop mk1B with 1220 Kg kaveri giving a thrust of 60/95 KN, taking a developmental time of 10 years,

Who will be the customer?

That's my doubt.

But 1250 KG KAVERI giving 60/95 KN is no slouch,

It can be an excellent fall back option for AMCA,

since we hv another decade to improve it & AMCA is still in design stages,


But as far as tejas is concerned, does it hv any impact?

 

[Pulkit]

GE 414 for mk2

Then why are you talking about 300kgs extra? You want GE to bring down wait or ADA DRDO to maintain some particular weight?
Or were you talking about GE 414 in tejas mk1?

GE 414 has better Engine Thrust to weight ratio than GE 404, So it can support the additional weight without cutting range, weapon load or ruining AOA, STR,ITR.

I am referring to thrust to weight ratio of engines.
i.e Engine Thrust / engine weight.

That's the proportion I was referring to.

It is a measure of engine's effectiveness in powering plane with better combat specs.

Instead of mk1A I typed mk2A by mistake , sorry for that.

np

There is no mk2A

There might be someday

 

[Pulkit]

Adding an extra stage will not make it as contemporary as other engine but heavier



The Mk2 weighs 8tons when empty and fully equipped with all the internal items and cannon.

I said 7200+ empty as of now there is no way to judge that So I will agree that it wont be lesser than 8 tons even if the target weight is 7200kgs

MK2 is having additional 1m length, larger wings which add to its airframe weight. Then it has AESA radar, SPJ, Laser pods, OBOGS, heavier landing gear, heavier engine etc which add 1.3ton of weight to the currently existing 6.7ton weight.

okay. but here you said 6.7 ton whereas I though the empty weight was close to 6.5.

The addition of weight between F414 an F404 is just about 45kg (4%) while the addition of thrust is about 16%.

here again I have different information that the difference is close to 300kgs but again these are the secret specs known to very few, so cannot argue with your quote. but given the dimensuions and power change I suspect it will be on the higher end and not mere 45.

So, this makes things easier to handle. However, if one is suggesting that Kaveri engine should have 20% or even 10% weight penalty over F404 but have same performance as F404, then it becomes too much to handle. Even a 10% penalty at 1200kg for 84-85kN Kaveri becomes unacceptable. TWR of 8 is minimum requirement for an engine to be reasonably good. Even engines like Al31F have 7.8 TWR.

Agreed

If the idea is to add a stage to F404 and maintain TWR of 8 while getting higher thrust, it is acceptable. An engine weighing 1225kg for 98kN engine is acceptable, even if it weighs 100kg over F414 as it still has TWR of 8. But 1200kg for 85kN will become too heavy

Agreed

 

[ersakthivel]

Then why are you talking about 300kgs extra? You want GE to bring down wait or ADA DRDO to maintain some particular weight?
Or were you talking about GE 414 in tejas mk1?
That's the proportion I was referring to. np
There might be someday

I said 300 KG extra, because I was replying to a suggestion by some one here,

Not my wish.

See my reply to
@Kshithij


To clarify this,..

I do Share your enthusiasm for mk2A or mk1B in my reply to,

@Kshithij
It has a good export prospect,


It will be even better if ADA goes for a twin engined stealth tejas , with whatever weight & thrust engine that comes out of snecma gtre jv.

A fighter slightly below AMCA,

It has even better prospect as it will be superior to rafale.

Since IAF has flown numerous MIG version, it can fly another three types of stealths,

Especially with so many MIGs, jags, mirages due to retire, it is a smashing option for IAF too,..AMCA, Rafale, FGFA, tejas, stealth tejas mk2A will form the bulk of the new additions for future needs,

But will IAF Prefer it over GE 414 MK2? especially waiting for another decade before it is completed, for its present & urgent needs?

Thats the ?

Any finished reliable jet engine with a TWR of 7.5, even if it weighs 1400 KG is a priceless asset.

But you need a new stealth twin engine fighter design, with range just below AMCA to justify inclusion in IAF.


Cant put that in tejas as of now.

 

[Kshithij]

Will IAF accept a lower thrust to weight ratio kaveri on mk2?

Mk1 & MK1A have GE 404 .

Mk2 has a bit heavier, but better Engine TWR 1120 KG GE 414,

If we hv to fit 1220 kg engine in mk2,

or

a new developmental version of mk1A, with a new name mk1B

Will IAF prefer it over GE 414 Engined mk2 ?
Because engine cost alone is not a significant fraction in a fighter cost.

1220kg engine with 62/96kN thrust is good enough for Tejas MK2. The 100kg extra over F414 is manageable. Kaveri engine, despite being heavier than F414 for same thrust, will be much better due to its indigenous manufacturing and the associated perks.

Also, AMCA has MToW of 24-25 tons which is similar to MToW of Rafale and EF Typhoon. So, twin Kaveri engine of 61/96kN would be more than enough for it. Even supercruise will be possible with the twin Kaveri engine. If AMCA was a heavier plane, then things would be much different. But the design of AMCA shown in defexpo appeared more like it was designed for speed than maneuverbaility. This in turn meant that it was

PS: the current Kaveri is expected to have 61/96kN thrust already with flat rating of 15%. So, the peak thrust while take-off is likely to be higher and so is the thrust for dogfight etc. The Kaveri will not have any Snecma parts but will only be audited by Snecma. Tejas MK1A will have K9 with slightly lower thrust while the same K9 is refined to K10 with F414 level thrust for Mk2. India has not ordered anymore F404 or F414 engines for the same reason. The imports are coming to an end

here again I have different information that the difference is close to 300kgs but again these are the secret specs known to very few, so cannot argue with your quote. but given the dimensuions and power change I suspect it will be on the higher end and not mere 45.

The fan size if bigger in F414 but the overall size of F414 is same as F404. The additional thrust comes from change in material and better design for improved cooling. The weight difference of 300kg is unlikely between F414 and F404 as that would be about 28% increase in weight for 16% increase in thrust.

 

[shiphone]

https://www.geaviation.com/sites/default/files/datasheet-F404-Family.pdf
https://www.geaviation.com/sites/default/files/datasheet-F414-Family.pdf

---------------------
22000 lb thrust, Thrust to Weight class :9:1.... the weight of F414 is around 2,445 lb/1100kg ( or 2365-2590 lb)...the difference is about 100kg (Max)

 

[Pulkit]

It has even better prospect as it will be superior to rafale.

Cannot say that, but given the assumptions we can hope that the final product will be better than Rafale.

Since IAF has flown numerous MIG version, it can fly another three types of stealths,

Out of the three stealth I am quite sure there will be re usability of various parts, which will make the use easier. IAF operates not just various versions of Migs but also various platforms which have no interchangeability

Especially with so many MIGs, jags, mirages due to retire, it is a smashing option for IAF too,..AMCA, Rafale, FGFA, tejas, stealth tejas mk2A will form the bulk of the new additions for future needs,

Timeline my friend is a biggest concern as of now. Tejas Mk2 will be inducted by 2028 they are saying and Tejas Mk1A by 2025 still not sure how these timelines are gonna work.

But will IAF Prefer it over GE 414 MK2?

No they won't. They will be questioning increase in cost, weight and reliability.

especially waiting for another decade before it is completed, for its present & urgent needs?

Thats what even i am worried. Now IAF being in control of Tejas in a year or two they are gonna say its not gonna meet there needs hence scrapping and getting foran mall. or will order 50 of them and scrap later like they did with ARjun.

Any finished reliable jet engine with a TWR of 7.5, even if it weighs 1400 KG is a priceless asset.

Any fighter jet engine is an asset. Thats why i count kaveri a success. had it been 80's it would have been accepted.

But you need a new stealth twin engine fighter design, with range just below AMCA to justify inclusion in IAF.


Cant put that in tejas as of now.

hmmm.... Tejas as of today cannot be modified to support twin engine, it has a single engine design base.

 

[Pulkit]

The fan size if bigger in F414 but the overall size of F414 is same as F404. The additional thrust comes from change in material and better design for improved cooling. The weight difference of 300kg is unlikely between F414 and F404 as that would be about 28% increase in weight for 16% increase in thrust.

I said on the higher side . Even i am not sure of the difference but 45kg your quote was a little too less.

Discounting all other factors just keeping change of material of core in mind i would assume a significant change in weight. Ass to generate more power they would need a denser material which will automatically increase the weight.

Just my assumption can some one find a source for this?

 

[ersakthivel]

I said on the higher side . Even i am not sure of the difference but 45kg your quote was a little too less.

Discounting all other factors just keeping change of material of core in mind i would assume a significant change in weight. Ass to generate more power they would need a denser material which will automatically increase the weight.

Just my assumption can some one find a source for this?

Weight difference is around 100 Kg about 9℅,
But thrust increase is 20%.

Thrust to weight ratio of GE 404 is 8.

For 414 it is 9.


Not necessarily denser material,

Better metallurgical SCB Blades with higher temp resistance & better cooling.

 

[ersakthivel]

Cannot say that, but given the assumptions we can hope that the final product will be better than Rafale. Out of the three stealth I am quite sure there will be re usability of various parts, which will make the use easier. IAF operates not just various versions of Migs but also various platforms which have no interchangeability Timeline my friend is a biggest concern as of now. Tejas Mk2 will be inducted by 2028 they are saying and Tejas Mk1A by 2025 still not sure how these timelines are gonna work. No they won't. They will be questioning increase in cost, weight and reliability. Thats what even i am worried. Now IAF being in control of Tejas in a year or two they are gonna say its not gonna meet there needs hence scrapping and getting foran mall. or will order 50 of them and scrap later like they did with ARjun. Any fighter jet engine is an asset. Thats why i count kaveri a success. had it been 80's it would have been accepted. hmmm.... Tejas as of today cannot be modified to support twin engine, it has a single engine design base.

French made mirage 4000 ,rapidly from mirage 2000,


I just hope V K.Saraswat"S stealth tejas concept takes wings with two stable kaveri engines,


It is a very low risk project for IAF as UTTAM ASEA, kaveri engine, Astra missile, variou PGMs, HMDS high off bore pyhton, OBORG, RS fly by wire software, & composites ,are already available.

 

[Kshithij]

French made mirage 4000 ,rapidly from mirage 2000,


I just hope V K.Saraswat"S stealth tejas concept takes wings with two stable kaveri engines,


It is a very low risk project for IAF as UTTAM ASEA, kaveri engine, Astra missile, variou PGMs, HMDS high off bore pyhton, OBORG, RS fly by wire software, & composites ,are already available.

AMCA is the stealth plane. There is no need for stealth Tejas. AMCA will be using Kaveri engines. Its MToW being just 25 tons, it doesn't take a new engine. Whatever engine goes into Tejas Mk2, same engine in twin engine format can be used in AMCA. 61|96kN Kaveri is good enough for AMCA for supercruise. Bigger engine will cause fuel outage and low range.

 

[ersakthivel]

Cannot say that, but given the assumptions we can hope that the final product will be better than Rafale. Out of the three stealth I am quite sure there will be re usability of various parts, which will make the use easier. IAF operates not just various versions of Migs but also various platforms which have no interchangeability Timeline my friend is a biggest concern as of now. Tejas Mk2 will be inducted by 2028 they are saying and Tejas Mk1A by 2025 still not sure how these timelines are gonna work. No they won't. They will be questioning increase in cost, weight and reliability. Thats what even i am worried. Now IAF being in control of Tejas in a year or two they are gonna say its not gonna meet there needs hence scrapping and getting foran mall. or will order 50 of them and scrap later like they did with ARjun. Any fighter jet engine is an asset. Thats why i count kaveri a success. had it been 80's it would have been accepted. hmmm.... Tejas as of today cannot be modified to support twin engine, it has a single engine design base.

This the worst blunder ever committed by the govt.
Does USAF own 's LM, BOEING?
Who has designed f22,F35,F16,F18?
Not the USAF.
This Air Marshal ,"MATHESHWARAN " wanted closed do em the SNECMA GTRE Jv on kaveri 5 years back, saying GTRE wouldn't learn anything from it..
Now the French are saying kaveri is a stable engine, & needs to be flight tested.
Another air force chief called tejas three leggef cheetah on its IOC day,
Much worse another IAF chief was hell bent upon stalling HTT 40 & argued PLIATUS will be cheap.
Another IAF Chief thundered he can design, produce fighters in IAF Base depots!!!
NAG, LCH, TEJAS,AGNI, BRAHMOS, N WEAPONS etc were all designed & fielded by DRDO HAL,
Navy has a full fledged design bureau & competent PHD holders to drive design. Renowned scientists like Arockiasamy Paul Raj were encouraged to pursue doctorate & put at the helm of Sonar design.
Army & IA has no institutional frame work for this.
Give HAL GTRE to IAF, They will shut down tejas, HTT 40 & ASK govt to assemble MNC fighters with golden screw driver tech in HAL & GTRE.

 

[Kshithij]

This the worst blunder ever committed by the govt.
Does USAF own 's LM, BOEING?
Who has designed f22,F35,F16,F18?
Not the USAF.
This Air Marshal ,"MATHESHWARAN " wanted closed do em the SNECMA GTRE Jv on kaveri 5 years back, saying GTRE wouldn't learn anything from it..
Now the French are saying kaveri is a stable engine, & needs to be flight tested.
Another air force chief called tejas three leggef cheetah on its IOC day,
Much worse another IAF chief was hell bent upon stalling HTT 40 & argued PLIATUS will be cheap.
Another IAF Chief thundered he can design, produce fighters in IAF Base depots!!!
NAG, LCH, TEJAS,AGNI, BRAHMOS, N WEAPONS etc were all designed & fielded by DRDO HAL,
Navy has a full fledged design bureau & competent PHD holders to drive design. Renowned scientists like Arockiasamy Paul Raj were encouraged to pursue doctorate & put at the helm of Sonar design.
Army & IA has no institutional frame work for this.
Give HAL GTRE to IAF, They will shut down tejas, HTT 40 & ASK govt to assemble MNC fighters with golden screw driver tech in HAL & GTRE.

That depends on what typeof officers are deputed to HAL. If worthless people with loud mouths are deputed, they will ruin it .But if intelligent people with proper understanding is deputed, they will sit with scientists and explain the problems and solutions asper their experience in flying planes which will help get things done quickly

 

[Kshithij]

ROFL!!!

This whackjob fought me for 2 weeks stating that a hypothetical 20% increase in engine weight for 20% increase in thrust will kill the aircraft.
Now the same clown is advocating twin engines on Tejas - 100% increase in engine weight for 100% increase in thrust!

@Willy3 Still enjoying being b!#(# to this loser?

Kaveri weighed 1200kg for 74kN thrust in 2011. Adding 20% weight to it would make it 1440kg for 90kN. This is the point of opposition. The point here is that TWR is important and must be 8. Thrust without TWR is not meaningful

 

[Pulkit]

French made mirage 4000 ,rapidly from mirage 2000,

The Industrial Setup and experience French had at the time which goes back to world War I era was much more mature and organized in comparison to what we have.
Still I wish what you said come to reality.

I just hope V K.Saraswat"S stealth tejas concept takes wings with two stable kaveri engines,

Will that still be a version of Tejas? That will be entirely new aircraft with some similarity in regard to part commonality with Tejas.

It is a very low risk project for IAF as UTTAM ASEA, kaveri engine, Astra missile, variou PGMs, HMDS high off bore pyhton, OBORG, RS fly by wire software, & composites ,are already available.

Yes we have these tech easily available but fitting them in a new platform will still be challenging.

 

[Pulkit]

This the worst blunder ever committed by the govt.

True, Like I said they are gonna bury it deep down.

Does USAF own 's LM, BOEING?
Who has designed f22,F35,F16,F18?
Not the USAF.
This Air Marshal ,"MATHESHWARAN " wanted closed do em the SNECMA GTRE Jv on kaveri 5 years back, saying GTRE wouldn't learn anything from it..
Now the French are saying kaveri is a stable engine, & needs to be flight tested.
Another air force chief called tejas three leggef cheetah on its IOC day,
Much worse another IAF chief was hell bent upon stalling HTT 40 & argued PLIATUS will be cheap.
Another IAF Chief thundered he can design, produce fighters in IAF Base depots!!!
NAG, LCH, TEJAS,AGNI, BRAHMOS, N WEAPONS etc were all designed & fielded by DRDO HAL,
Navy has a full fledged design bureau & competent PHD holders to drive design. Renowned scientists like Arockiasamy Paul Raj were encouraged to pursue doctorate & put at the helm of Sonar design.
Army & IA has no institutional frame work for this.
Give HAL GTRE to IAF, They will shut down tejas, HTT 40 & ASK govt to assemble MNC fighters with golden screw driver tech in HAL & GTRE.

IAF is not gonna support a home built aircraft ever...... Just wonder why ?

 

[Advaidhya Tiwari]

The Industrial Setup and experience French had at the time which goes back to world War I era was much more mature and organized in comparison to what we have.
Still I wish what you said come to reality.

France had been completely invaded by Germany in WW@. Also, the old technology of the past is nothing with the arrival of supercomputers. So, it is incorrect to glorify France. Indian technology levels as of now is not below French levels of 1980s when they made M88 engines.