ADA Tejas (LCA) News and Discussions

[p2prada]

The nose, air intakes and wings are set to be redesigned.

 

[Mustang]

The intakes are mostly going to be rectangular.

But I always wonder about one thing. People claim both JAS gripen and LCA are same / same category. But why is LCA being re-designed to accomodate a better engine?.if it they are same, then why not just redesign to make it equal to JAS gripen with GE-F404?.

Both aircrafts, with same weight, almost same payload, almost same range should have same engine, isn't it?..If one ends up having a more demanding engine (GE424) interms of fuel and heavier than the engine in JAS gripen, it says clearly that something is not that correct in LCA. It could be its intakes or perhaps not having canards like gripen.

After GEF414 is installed, people cannot claim it to be similar to Gripen NG which has GE-F414.

 

[Parthy]

Any wind tunnel model of LCA2??

 

[slenke]

The intakes are mostly going to be rectangular.

But I always wonder about one thing. People claim both JAS gripen and LCA are same / same category. But why is LCA being re-designed to accomodate a better engine?.if it they are same, then why not just redesign to make it equal to JAS gripen with GE-F404?.

Both aircrafts, with same weight, almost same payload, almost same range should have same engine, isn't it?..If one ends up having a more demanding engine (GE424) interms of fuel and heavier than the engine in JAS gripen, it says clearly that something is not that correct in LCA. It could be its intakes or perhaps not having canards like gripen.

After GEF414 is installed, people cannot claim it to be similar to Gripen NG which has GE-F414.

I'm not an engineer, I do finance.

But I believe it has something to do with canards because canards reduces drag and increases lift, if they're well designed of course.

Why did they decide to make the Tejas mk2 without canards?

 

[death.by.chocolate]

I'm not an engineer, I do finance.

But I believe it has something to do with canards because canards reduces drag and increases lift, if they're well designed of course.

Why did they decide to make the Tejas mk2 without canards?

Because the LCA does not need canard, the LCA does not have a conventional delta wing.
The LCA's wing is a compound delta wing somewhat similar to the F-16 XL "Cranked Arrow".
A LCA's compound delta high set twisted wing with hidden CFD chambers allows for higher angle of attack
at lower speeds this is an advantage over traditional delta wings but not quite
the same low speed AoA performance of a euro canard delta design.

Finally, every design involves a trade off and performance penalties in certain flight regimes.
Delta canard designs prevents wing stall at high AoA and enhances STOL capability.
However,the delta canard design has limitations as well and no canards do not reduce drag.
In fact, adding canards to a traditional delta wing increases drag and reduces
the transonic performance of a conventional delta design.

 

[plugwater]

Eurojet pays dearly for engine re-bid delay

European aerospace firm Eurojet missed being declared the lowest bidder — L1 — by a whisker for the engine deal of the indigenous light combat aircraft (LCA) Tejas Mark-II being developed by Aeronautical Development Agency (ADA).

The European consortium is engaged in a fierce battle with the American GE Aviation for providing technology and consultancy for the manufacture of 99 engines for the LCA Tejas Mark-II.

An official with knowledge about the bid, on the condition of anonymity, said Eurojet had submitted its revised bid on September 28 and it reached the Defence Research and Development Organisation (DRDO) on September 29.

"Eurojet marred its chance by submitting its bid a day before the announcement (of L1 biddder) was made — September 30. And so their revised bid was not considered," he said.

He said Eurojet's revised quotation for manufacturing of its EJ200 indigenously is lower than GE's F-414 by $80-100 million.


According to sources, after reworking the bid and providing the details soughtby the price negotiation committee, the European consortium's tender price is around $900 million while that of GE is $980 million. In the initial round, Eurojet's bid was reportedly lower at $666 million compared with GE's $822 million. It is learnt Eurojet's price had shot up because it had not clearly specified certain items in its bid.

One of them was the $65 million cost of tools, which it is giving on 'free on loan' - meaning the tools would be returned on completion of the project.

GE, on the other hand, is providing the tools totally free.

"This and other costs, which were specified more clearly in response to queries from the price negotiation panel has closed the gap between Eurojet and GE but European engine maker's bid is still lower than GE," said a source.

Though, another source, who did not want to be named, said initially Eurojet's bid had shot up to over $1000 million after they clarified certain expenses in the tender.

"They rushed to correct that (their bid climbing higher than GE's) but by the time they came back with a revised bid, it was too late," he said.

Price negotiation committee chairman and chief controller - R&D - of DRDO Dr CK Prahlada could not be reached for comments.

The LCA Tejas Mark-II is an upgraded version of the current Mark-I, which uses GE's F404 engine.

Eurojet pays dearly for engine re-bid delay - Money - DNA

 

[ppgj]

a good decision regards F414 for LCA. we need to speed up and finalise LCA mark 2 and operationalise it ASAP.

EJ200 while being a later generation with good potential has not been able to enhance the thrust to what IAF requires which is 95 - 100kn. with Europe reeling under finacial mess and with partner countries cutting their own commitments for EF Typhoon in particular and defence budgets in general, the additional thrust for the engine seems distant. so the planned Stage 1 (20% increase) and Stage 2 (30% increse) remains on paper atleast for now.

OTOH F414 already has enough thrust to deliver as per IAF requirement and has plans for an EPE engine for an additional 20% thrust though they want an international customer for that. in the meanwhile they are working on an EDE version to increase durability and better SFC on F414 (for the US).

New GE Engine Has Potential For Commercial Use | AVIATION WEEK

Boeing's Super Hornet seeks export sale to launch 20% thrust upgrade

F414 is a very reliable and mature engine and 1000th engine was delivered recently.

GE Aviation: Powerful Past, Promising Future Mark 1000th F414 Engine Milestone

the higher thrust will give LCA a great T/W ratio and making it very nimble. it is important to remember an AESA is being planned for LCA in sometime which means higher "power" requirement and considering european requirement cuts, it seems a lengthy road for the extra thrust to become a reality. even if IAF had opted for EJ200 the TOT and assembly lines and tools would have have cost much higher as admitted by the consortium. also as "death by chocolate" rightly pointed out EJ200 is not certified for single engine fighters.

i guess it was a pragmatic and a realistic decision to opt for F414 without any loss of more time, an urgency by IAF in favour of LCA M2 augurs well for the LCA future.

people need also to remember LCA mark 1 indeed has an american GE engine F404IN20 and hence the ADA seems it logical to go for F414 which is a further development of F404 - which enhances the relationship they have already built up with the GE.

while members here may have reservations going for GE which is understandable but i guess GOI is taking enough precautions and may be we do not know something is cooking between India and the USA which may turn out good as for as high end defence technology import is concerned where the US is a clear leader - if one goes by lot of american buys in the recent past.

 

[slenke]

Because the LCA does not need canard, the LCA does not have a conventional delta wing.
The LCA's wing is a compound delta wing somewhat similar to the F-16 XL "Cranked Arrow".
A LCA's compound delta high set twisted wing with hidden CFD chambers allows for higher angle of attack
at lower speeds this is an advantage over traditional delta wings but not quite
the same low speed AoA performance of a euro canard delta design.

Finally, every design involves a trade off and performance penalties in certain flight regimes.
Delta canard designs prevents wing stall at high AoA and enhances STOL capability.
However,the delta canard design has limitations as well and no canards do not reduce drag.
In fact, adding canards to a traditional delta wing increases drag and reduces
the transonic performance of a conventional delta design.

But they could have gone with a close-coupled canard design. The current Tejas design clearly suffers from issues with drag, or am I wrong?

Canard allows for reduced trim drag,
especially supersonic

http://www.aoe.vt.edu/~mason/Mason_f/canardsS03.pdf

Many current aircraft designs for future air-superiority fighters incorporate close-coupled canards. This relatively new configuration has been developed, principally, through wind tunnel testing that indicates a favorable aerodynamic interaction between the canard and wing at high incidence. The favorable interaction creates a high total lift capability and reduced trimmed drag, leading to important gains in combat effectiveness. The investigation here is directed at obtaining a physical understanding of the canard/wing flowfield and then building from it an analysis of the aerodynamic interaction. Wind tunnel tests were carried out on a representative configuration in the NASA Langley Research Wind Tunnel.

Aircraft Testing

 

[death.by.chocolate]

But they could have gone with a close-coupled canard design. The current Tejas design clearly suffers from issues with drag, or am I wrong?

Drag? I don't recall reading about drag problems? Canards can be dangerous due to pitch instability and sensitivity to CG(center of gravity). I don't think there is a production canard delta, close coupled or otherwise that isn't AoA (angle of attack) limited. Experienced pilots are able to fully exploit the benefits of this design and avoid unsafe flight regimes. Of course, this is not a problem during peace time when you can take your time training pilots. But will present problems when you wish to ramp up by rapid induction of new pilots or quickly replace pilots that have been lost in combat.

Finally, the subject you wish to discuss is complex - but I doubt the Tejas will sprout a close-coupled canard in the foreseeable future.
They may however incorporate leading edge vortex controllers from the Tejas Naval design into block II variants.​

 

[nitesh]

Price Talks Imminent On GE F414 Engine For India LCA | AVIATION WEEK

The F414-GE-INS6 is the highest-thrust F414 model. It boasts Full Authority Digital Electronic Control (FADEC) and additional single-engine safety features. "GE keeps infusing the latest technology," a company official says. "If, for instance, we have a version 12 of the blade, the customer gets just that."

Helping seal the deal was GE's offer to provide increased technical manpower and base workers in India to help develop the engine, officials said.

The contract requires 8-10 engines to be provided in fly-away condition, with the rest to be delivered in semi-knocked-down condition and assembled in India. The agreement also contains a 30% offset clause and will tap some of the 24 Indian companies that GE has certified. "The deliveries will depend on when the development phase of the LCA is over," and official says.

A remaining point of contention is the technology transfer clause.

"The requirement and conditions were not clear," an engine manufacturer says. "You cannot offer a product unless you know how it will be used. Besides, you need to consider which of the two technologies are more advanced." GE requires U.S. government clearance for transfer of technology. "We can almost be sure there will be no transfer of crystal blades of the F414," an analyst says.

While the LCA Mk2 has been slated for production by 2014, that is seen as a distant dream, an analyst says. The new aircraft's fuselage and components need to be modified and put through armament tests, and the behavioral patterns of the aircraft will change accordingly. The LCA Mk 2 also will need to undergo at least four technology demonstrators that will delay military commissioning beyond 2014, the analyst said.

 

[SATISH]

Delta canards have a problem also with sending the aircraft into autorotation.. This was highly evident in the Lavi design and is also faced by a few Gripen pilots lately. and the air flow obstruction of the canted canards in the EF is because of it. The worst is visibility problems.

 

[pmaitra]

Delta canards have a problem also with sending the aircraft into autorotation.. This was highly evident in the Lavi design and is also faced by a few Gripen pilots lately. and the air flow obstruction of the canted canards in the EF is because of it. The worst is visibility problems.

Correct me if I am wrong, as I am no aerospace engineer, but isn't the LCA deliberately designed to be unstable in nature, the auto-rotation being one of the many phenomena expected from such a design?

From what I know, an electronic control system keeps the LCA (and such aeroplanes) in control which is switched off at the time of combat, therefore making the plane highly maneuverable.

Hence, the auto-rotation thing is not a bane, but a boon and that 'problem' is already taken care of by the control system.

 

[SATISH]

Correct me if I am wrong, as I am no aerospace engineer, but isn't the LCA deliberately designed to be unstable in nature, the auto-rotation being one of the many phenomena expected from such a design?

From what I know, an electronic control system keeps the LCA (and such aeroplanes) in control which is switched off at the time of combat, therefore making the plane highly maneuverable.

Ok...lets start with the Flaws of the delta wing design. The delta wing design is built for speed. You must accept that the delta bleeds more energy than the conventional swept wing. This is oneof the properties of the delta. Once the delta bleeds energy it directly translates to loss of altitude during ACM. If the pilot tends to enter into an autorotation at a low altitude the time taken to recover his aircraft is drastically reduced compared to the conventional swept wing. Autorotaion tends to make the aircraft to lose its lift. This was clearly seen in the Lavi and is still being seen in the J 10.This was first noticed in the MiG 21.

Canrds also translates into more moving parts which also makes the aircraft a bit harder to maintain. LCA is supposed to be the "cannon-fodder". not an aircraft to challenge the F 15 or an SU 27 on paper.

 

[pmaitra]

Ok...lets start with the Flaws of the delta wing design. The delta wing design is built for speed. You must accept that the delta bleeds more energy than the conventional swept wing. This is oneof the properties of the delta. Once the delta bleeds energy it directly translates to loss of altitude during ACM. If the pilot tends to enter into an autorotation at a low altitude the time taken to recover his aircraft is drastically reduced compared to the conventional swept wing. Autorotaion tends to make the aircraft to lose its lift. This was clearly seen in the Lavi and is still being seen in the J 10.This was first noticed in the MiG 21.

Canrds also translates into more moving parts which also makes the aircraft a bit harder to maintain. LCA is supposed to be the "cannon-fodder". not an aircraft to challenge the F 15 or an SU 27 on paper.

LCA, to my mind is a replacement for MiG-21. Calling it cannon-fodder would be an overstatement.

Delta wing has some advantages vis-a-vis swept wings:

• Better structural Integrity
• Better speed
• Higher stall angle
• Inferior lift (although this does not hold true for highly swept wing configurations)

However, my question still remains, and let me clarify:

• Is the auto-rotation a phenomenon of delta wings? Could someone provide some references or link?
• The LCA is an unstable aircraft, however, does this instability cause the plane to auto-rotate?

 

[SATISH]

LCA, to my mind is a replacement for MiG-21. Calling it cannon-fodder would be an overstatement.

Delta wing has some advantages vis-a-vis swept wings:

• Better structural Integrity
• Better speed
• Higher stall angle
• Inferior lift (although this does not hold true for highly swept wing configurations)

However, my question still remains, and let me clarify:

• Is the auto-rotation a phenomenon of delta wings? Could someone provide some references or link?
• The LCA is an unstable aircraft, however, does this instability cause the plane to auto-rotate?

I was talking about delta canards inherent properties. Not about LCA. LCA is a ranked delta. Scroll up and read DBC's post and you will understand.

And the Lo-End aircraft of any airforce is called as cannon fodder. For example the F 16 in USAF is called by the USAF as the Lawn Dart. Does that make it inferior?

 

[pmaitra]

I was talking about delta canards inherent properties. Not about LCA. LCA is a ranked delta. Scroll up and read DBC's post and you will understand.

And the Lo-End aircraft of any airforce is called as cannon fodder. For example the F 16 in USAF is called by the USAF as the Lawn Dart. Does that make it inferior?

By DBC, did you mean 'death.by.chocolate'? Yeah, I had already seen his post. Thanks.

Sorry, I misunderstood and confused canards with the word delta. It's easy to confuse because the term 'delta-canard layout' does not indicate only the canards but the entire configuration which consists of the canards as well as the wings.

 

[gogbot]

The Tejas is the Low end of the IAF what ever way you look at it i suppose.

That's only because we are getting so many other High end aircraft.

Name one other airforce in the world that will be inducting its first indigenous 4th genFighter , Then an upgraded indeginous 4.5 gen Fighter and then a JV 5th gen fighter all in one decade.

But i still think the Tejas is good enough to trump Mirage-2000 and our configurations of Mig-29's

 

[Agantrope]

The Tejas is the Low end of the IAF what ever way you look at it i suppose.

That's only because we are getting so many other High end aircraft.

Name one other airforce in the world that will be inducting its first indigenous 4th genFighter , Then an upgraded indeginous 4.5 gen Fighter and then a JV 5th gen fighter all in one decade.

But i still think the Tejas is good enough to trump Mirage-2000 and our configurations of Mig-29's

Designers had in mind that they are not going to take up with the raptor, so tejas was designed as now what it is. Also we are not going to take over the pilots like in RAF. SO again it is what it is.

Tejas mk-1 is overkill when compared to Bison as per IAF chief's statement, which inturn gives our neighbours a bloody nose.

 

[Shaitan]

Omg when is the Induction!

 

[p2prada]

Name one other airforce in the world that will be inducting its first indigenous 4th genFighter , Then an upgraded indeginous 4.5 gen Fighter and then a JV 5th gen fighter all in one decade.

Not a big deal. Most airforces have already inducted their own 4th gen fighter a decade ago and are inducting their upgraded 4.5th gen fighter along with a 5th gen JSF in the same decade. We are behind actually.