ADA Tejas (LCA) News and Discussions

[Kunal Biswas]

You have DRDO chief from aeronautical dept in charge now, And new HAL chief is placed for specific duties towards Indigenous production ..

I am expecting a boom in Tejas progress both in research and production ..

pl elaborate

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Its quite conflicting taking your view about that GE-414 is of same length of GE-404-IN, In that case why it is said that the Aircraft length will be increased by few inches due to the engines ?

And your second statement is it a question/comment?

 

[Pulkit]

You have DRDO chief from aeronautical dept in charge now, And new HAL chief is placed for specific duties towards Indigenous production ..

I am expecting a boom in Tejas progress both in research and production ..



================

Its quite conflicting taking your view about that GE-414 is of same length of GE-404-IN, In that case why it is said that the Aircraft length will be increased by few inches due to the engines ?

Kunal That is what we call maximum length maximum diameter thing.

The design is done within a certain volume in mind.

Just as i gave a example earlier I will like to say , cone and cylinder having same diameter and length are not same at all.

The length is gonna increase due to

1) Increase the capacity of fuselage
2)Accomodate New Engine

I think I have clarified what I am saying.
It is about Max length/diameter .


Length of engine is not uniform nor it is diameter its not a cylinder it has various components which do not even fall with the shell .

Though I will like to add I am no expert so if you think I am quoting wrong let me know.

I will be consulting few seniors who have been to production line and ask them the same question(commercial not defense)

 

[sgarg]

@Pulkit, I should give you an example. New engines are being considered for Jaguar which are far more powerful compared to existing engines. These engine being discussed does not require fuselage changes.

Yes F414 and F404 may not be exactly identical (though they have same diameter and length) but the fuselage can accommodate F414 as it has the space.

I think length issue is being mixed up with engine. These are different things. Tejas internal fuel capacity is small and that is the primary reason for length increase. Length increase is just 0.5 meter.

I expect internal fuel capacity to go up by 500 liters. The increased fuel capacity will help with ferry range and combat radius.

The plane's center of gravity will change due to length increase and its flight characteristics will change so the plane will definitely require testing and refinement.

 

[grampiguy]

Any news about the gun integration in the Tejas MK-1 ? Has the aircraft been integrated with the gun? Any authoritative news link on its integration, vibration tests and flight testing?

 

[Pulkit]

@Pulkit, I should give you an example. New engines are being considered for Jaguar which are far more powerful compared to existing engines. These engine being discussed does not require fuselage changes.

Yes F414 and F404 may not be exactly identical (though they have same diameter and length) but the fuselage can accommodate F414 as it has the space.

I think length issue is being mixed up with engine. These are different things. Tejas internal fuel capacity is small and that is the primary reason for length increase. Length increase is just 0.5 meter.

I expect internal fuel capacity to go up by 500 liters. The increased fuel capacity will help with ferry range and combat radius.

The plane's center of gravity will change due to length increase and its flight characteristics will change so the plane will definitely require testing and refinement.

I am not aware of Jags New engines .
I am not home but in office If you can share the source I might be able to comment.

I am not mixing anything here.

If you have read my comments I just wanna tell you that they want to increase fuel capacity and fit a more powerful engine .

Just on the basis of hard and fast rule If New Engine of Jags are having a little bit difference say in weigth / dimensions / power the structure need to be hardened modified to suite it.

 

[Pulkit]

@Kunal Biswas

From commercial aircraft point of view.

A aircraft was being modified to improve its passenger carrying capacity .
Which lead to change of position of its wings,fuselage, windows,Frame,stringers.

The increase in Skin Panel Change was even more difficult as some people working with composite claim that they had to redesign it entirely.

If to go into little depth the thickness on skin varies from zone to zone based on the attachments and other secondary structures.

Just to add to it some one was working on some part of defense aircraft no windows only doors structure was made to change an entire region because company was not able to pass one titanium component.

Just because one nut and bolt was of european standards and not american standards we had to change a whole process.

This is the level of attention given on even the smallest of details .
Only if these benchmarks are not set for us (ADA DRDO HAL) change of Entire Engine has no effect.

 

[Kharavela]

You have DRDO chief from aeronautical dept in charge now, And new HAL chief is placed for specific duties towards Indigenous production ..

I am expecting a boom in Tejas progress both in research and production ..

These are indeed good news, but on expected lines from #ModiSarkar. HAL effort to double production numbers for #Tejas will also be cleared soon. Even IAF will provide its share of money for new production line, whether some retired Chair Marshals like it or not.

I'm eagerly waiting for NP2 taking off to the sky from SBTF.

 

[lcafanboy]

HAL's Tejas passes cold-weather test at Leh
The aircraft made three consecutive starts using indigenous gas turbine starter at minus 15 degrees Celsius
BS Reporter | Bengaluru
February 2, 2015Last Updated at 19:42 IST
Hindustan AeronauticsLimited (HAL) has completed extreme cold weather trials on ligh combat aircraft (LCA) -Tejasat Leh, in Ladakh in January this year.
"The aircraft made three consecutive starts using indigenous gas turbine starter at minus 15 degrees Celsius with 85 per cent charged battery a few days ago. Prior to the start, the aircraft was cold soaked for 18-20 hours (even 42 hours on one occasion) outside the hangar in Leh and no heating source was used for starting," T Suvarna Raju, Chairman, HAL, said in a release.
A team of 15 engineers and technicians fromHALworked to solve the problems faced in starting a gas turbine engine in the ratified and cold atmospheres of Leh. The gas turbine starter unit of HAL used to start the engine for theLCAhas been designed, developed and manufactured by HAL's aero engine R&D centre and Aero Engine Research and Design Centre (AERDC). The first success was the rig trials with a modified starting schedule conducted at Leh (3,260 m altitude) in July and August 2014. During this period, HAL also demonstrated the start capability of its starter even at a high altitude of 5.6 km, the statement added.

 

[sgarg]

I am not aware of Jags New engines .
I am not home but in office If you can share the source I might be able to comment.

I am not mixing anything here.

If you have read my comments I just wanna tell you that they want to increase fuel capacity and fit a more powerful engine .

Just on the basis of hard and fast rule If New Engine of Jags are having a little bit difference say in weigth / dimensions / power the structure need to be hardened modified to suite it.

Your question has been adequately answered by more than one poster. It is a question of design adopted in Tejas. The choice of engine is not something new. The engine choice is based on suitability with the airframe.

your experience is valid for the situation with that particular aircraft. Military aircraft are over-designed as combat situation can put lot of stress on the airframe.

 

[Pulkit]

Your question has been adequately answered by more than one poster. It is a question of design adopted in Tejas. The choice of engine is not something new. The engine choice is based on suitability with the airframe.

your experience is valid for the situation with that particular aircraft. Military aircraft are over-designed as combat situation can put lot of stress on the airframe.

There is something you are ignoring and that is when it comes to Military aircraft the "Factor of Safety" becomes way lot rigid.
Kindly do share the answers posted by more than one posters where I have not replied adequately.
I have never said I am a expert but I have worked on aircrafts . Not a military aircrafts but yes aircrafts.

When a military aircraft is built it is built based on huge "FOS" and that cannot be put on test.

At the speed the aircrafts fly even a small risk is not to be taken .

Okay one thing more.
Stress yes thats a huge thing to talk about.
When i talk about airframe/Structure engine needs to be stable and properly fit even that needs changes .

you are not sticking to basics but believing in what you want to believe.

I am only saying.....


"WHEN IT COMES TO ANY CHANGE IN AIRCRAFT LET IT BE MILITARY OR CIVIL , THE IMPACT IS HUGE AND COVERS EACH AND EVERY COMPONENT"
@Kunal Biswas sir do you know any person having experience of working in HAL ADA we can consult them.


Internet does not display the manufacturing and designing limitations. Somebody with first hand experience can explain it more properly than me.

 

[Kunal Biswas]

I think we have here, But its highly unlikely he would like to be called here ..

 

[Pulkit]

I think we have here, But its highly unlikely he would like to be called here ..

If not on post one can any day drop you a message.

Do share your views.

 

[sgarg]

@Pulkit, I have not seen "any news" regarding redesign/strengthening of Tejas airframe for fitting F414 engine. I do not question your experience/knowledge. All I am saying is that Tejas designers are/were aware of F414 engine for a very long time. They are likely to take care of this by now as Dr Saraswat has said.

Can you quote some other military fighter program (maybe Western) where engine was changed - in terms of changes made to airframe??

A civilian aircraft is built for efficiency (fuel efficiency), as it flies a lot more than a fighter aircraft. It is logical that civilian aircraft needs redesign for engine change. Fuel efficiency is not topmost concern in a fighter.

 

[Pulkit]

@Pulkit, I have not seen "any news" regarding redesign/strengthening of Tejas airframe for fitting F414 engine. I do not question your experience/knowledge. All I am saying is that Tejas designers are/were aware of F414 engine for a very long time. They are likely to take care of this by now as Dr Saraswat has said.

Can you quote some other military fighter program (maybe Western) where engine was changed - in terms of changes made to airframe??

A civilian aircraft is built for efficiency (fuel efficiency), as it flies a lot more than a fighter aircraft. It is logical that civilian aircraft needs redesign for engine change. Fuel efficiency is not topmost concern in a fighter.

Sgarg i have requested kunal sir to refer a defense engg for this.
Will wait for the same.

 

[shiphone]

I'm wandering in your minds ,is the intake a part of airframe? if it is , too many examples and it would be much easier to explain the Airframe changes when the new engine comes...and if the engine changed, Normally the engine bay would be changed as well, it's a very simple fact...
----------
1. in the F16 development history, the first block with exchangable F110/F100 serial engine (the earlier blocks use F100 only) is Block30/32...since this block ,two important changes are there:

(1) a redesigned universal engine bay for both F100/F110 engine, which means Block 32 could use the F110 engine and Block 30 could use the F100 engine as well...but, such thing never happened, the interchangeability is just available with this new universal engine bay.

(2)MCID vs NSI intake.--- it is due to F110 requirement of more air than the F100 serial... (PS. LCA Mk.2 would have the air intake enlarged due to the same reason)...

2. a bad example here, the F-4K(Royal Navy) and F-4M(Royal AF)... British insisted to equipt own Rolls Royce RB.168-15R（Spey）to replace the J79. so the engine bay was enlarged to adapt the bigger Diameter Spey engine, which brought more drug, the whole aft. fuselage was redesigned as well...this change resulted in the performance loss in top speed, acceleration, ceiling, climbing rate, but the range ,low speed performance was improved...

F-4K and F-4D

 

[karn]

@shiphone What you say is true but the LCA was designed with the kaveri engine from the start .. which has the airflow requirements of the 414 engine.

 

[shiphone]

@shiphone What you say is true but the LCA was designed with the kaveri engine from the start .. which has the airflow requirements of the 414 engine.

do you mean MK1 or Mk2?

1. Mk2 would enlarge the air intake for the 16% increased airflow of F414 engine...if MK1 was designed with the requirement of so called "Kaveri airflow at the same class of F414" , such change on Mk2 is not necessary...

2. so called "kaveri engine has the same airflow requirements of the 414 engine" is a very strange claim... kaveri is just a 8+ ton thrust engine but F414 is a 10 ton class one, normally more thrust with more airflow. especially the Kaveri is also a low bypass ratio design...

-------------------------------
my yesterday's post was interrupted by the coming job...the post continued here...

3.. a Reversed Example here...F14A+/B/D's F110-400 replacing the F14A's TF-30 Engine.

the early engine on F14A--- TF-30 is very problematic one...so when USAF chose the GE's F110 serial as the second Engine project, USN also shew the interest...F110 is more advanced ,compacted and shorter than the original TF-30's engine. but to fitting on the old ,'big' engine bay on F14A, some change/adjustment happened on the Engine not the air-fame of plane...a special model F110-400 was designed ,sharing the 80% similarity with F110-100...the after burner section was increased about 1.22 meters which is an obvious adjustment..

the F14 complicated/ high-efficiency super sonic air intake design could adapt the new engine well but certainly some adjustment was also done ...in other cases like the constant air intake design (LCA's is one of them), some redesign/restructure should be unavoidable...

4.. a very straightforward example here... F-18C/D's F404--F-18E/F' F414 evolution.

F-18C's 'D shape' air intake

F-18E's CARET intake with 18% more airflow...of course , the increased airflow is just part of benefits, others like the better supersonic performance, stealth etc . are also very impressive...F-18E basicly is an 25% Enlarged F18C, so every sub-section was larger/bigger ...

although the GE claimed the the F414's total length and "aft. section" or max Dimension is unchanged .but it doesn't mean F414's size is exactly the same as F404 at the each sections...at least the FAN section's size is increased due to increased airflow ...

but it should not be a big deal coz normally the engine bay is a cylindrical, withdrawable design with the same max Dimension.

so Changing the engine is not an simple thing, some necessary redesign/restructure/Change would happen not only on the airframe but also the engine possibly... it would be much better to discuss the different situation in different cases...
---------------

anyway ,LCA mk2 would have the airframe changed not only for fitting the new F414 engine, 05.m Extension of the fuselage ,but also the restructure job for weight reduction which has been listed on top of the improvement list of ADA post. Indian designers and engineers should have learn quite some knowledge and experience in the past decades ...with these new understanding , they might cut quite some wight off but keep the structural strength, help to simplify the manufacture , and improve the performance in the end...

 

[ersakthivel]

do you mean MK1 or Mk2?

1. Mk2 would enlarge the air intake for the 16% increased airflow of F414 engine...if MK1 was designed with the requirement of so called "Kaveri airflow at the same class of F414" , such change on Mk2 is not necessary...

2. so called "kaveri engine has the same airflow requirements of the 414 engine" is a very strange claim... kaveri is just a 8+ ton thrust engine but F414 is a 10 ton class one, normally more thrust with more airflow. especially the Kaveri is also a low bypass ratio design...

-------------------------------
my yesterday's post was interrupted by the coming job...the post continued here...

3.. a Reversed Example here...F14A+/B/D's F110-400 replacing the F14A's TF-30 Engine.

the early engine on F14A--- TF-30 is very problematic one...so when USAF chose the GE's F110 serial as the second Engine project, USN also shew the interest...F110 is more advanced ,compacted and shorter than the original TF-30's engine. but to fitting on the old engine bay on F14, the change happened on the Engine not the airfame of
plane...F110-400 was designed sharing the 80% similarity with F110-100...the after burner section was increased about 1.22 meters which is an obvious adjustment..

the F14 complicated/ high-efficiency super sonic air intake design could adapt the new engine well but certainly some adjustment was also done ...in other cases like the constant air intake design (LCA's is one of them), some redesign/restructure should be unavoidable...

4.. a very straightforward example here... F-18C/D's F404--F-18E/F' F414 evolution.

F-18C's 'D shape' air intake

F-18E's CARET intake with 18% more airflow...of course , the increased airflow is just part of benefits, others like the better supersonic performance, stealth etc . are also very impressive...

although the GE claimed the the F414's total length and "aft. section" or max Dimension is unchanged .but it doesn't mean F414's size is exactly the same as F404 at the each sections...at least the FAN section's size is increased due to increased airflow ...

but it should be not big deal. normally the engine bay is a cylindrical, withdrawable design with the same max Dimension.

so Changing the engine is not an simple thing, some necessary redesign/restructure/Change would happen not only on the airframe but also the engine possibly... it would be much better to discuss the different situation in different cases...
---------------

anyway ,LCA mk2 would have the airframe changed not only for fitting the new F414 engine, 05.m Extension of the fuselage ,but also the restructure job for weight reduction which has been listed on top of the improvement list of ADA post. Indian designers and engineers should have learn quite knowledge and experience in the past decades ,with these new understanding , they might cut quite some wight off but keeping the structure intension, simplify the manufacture , and improve the performance in the end...

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To address the IAF's 1995 ASR fully, work is now underway on the Tejas Mk-II which will sport a new and more powerful engine in the form of General Electric's (GE's) 98 kilo newton generating F414-GE-INS6 , 99 units of which have already been ordered. The F414-GE-INS6 replaces the current MK-I engine which is the F404-GE-IN20. Contrary to earlier speculation, Dr Tamilmani says that the Tejas Mk-II does not require an intake re-design since the MK-I intake was in any case intended to be used with the Kaveri engine which has a greater mass flow than the current F404-GE-IN20 . Studies have shown that the existing intake can easily handle the additional mass flow from the F414-GE-INS6.

As official as it gets about air intake of tejas.

 

[karn]

Saurav Jha's Blog : The Radiance of Tejas: A bright prospect for 'Make in India'
From the horses mouth .

Contrary to earlier speculation, Dr Tamilmani says that the Tejas Mk-II does not require an intake re-design since the MK-I intake was in any case intended to be used with the Kaveri engine which has a greater mass flow than the current F404-GE-IN20 . Studies have shown that the existing intake can easily handle the additional mass flow from the F414-GE-INS6.

There are many refinements beyond just a new engine @shiphone
Perhaps in the future a new intake will be designed but the tejas 2 is required urgently .
Heh .. Esakthi ninjaed me

 

[shiphone]

Bharat Rakshak • View topic - Aero India 2013

Aero 2013...Kartik from BR forum..

Attended my first Aero India this Saturday. I won't describe the difficulties in getting into the show, but once I did, it was quite alright. The highlight for me was the conversations I had with Cmde Jaydeep Maolankar, Test Pilot of the Tejas program and Cmdr Sukesh Nagaraj (Deputy Project Director, NLCA).

Attended my first Aero India this Saturday. I won't describe the difficulties in getting into the show, but once I did, it was quite alright. The highlight for me was the conversations I had with Cmde Jaydeep Maolankar, Test Pilot of the Tejas program and Cmdr Sukesh Nagaraj (Deputy Project Director, NLCA). I was lucky to spot Mao sir alone and walked up to him, introduced myself and spoke of my association with BRF and then we had a conversation on the Tejas program for half an hour..he was incredibly frank, friendly, didn't hold back any facts and only left when he got a call from someone..here are the salient points of our conversation, some of which we already know but am listing it anyway.

- Tejas LSP6 is the platform on which the spin chute will be integrated but it's not here as yet. Will get done before FOC.
- Tejas Mk1 has achieved the IOC AoA limit of 22 deg and they will go a couple of degrees further in tests, when the spin chutes are integrated on LSP6. This is to ensure that they know that the airplane is safe even at higher alpha although the FBW will restrict it to the AoA limit for FOC for service pilots (which is higher than 22 deg, but he didn't say how much)
- Mao Sir scoffed at the suggestion that the engine was choking at higher alpha. He said there is no such thing, but rather because it was designed initially for the Kaveri's airflow and had to redesign it for the F-404. They have already tried various intakes on the LCA, with/without spring mounted doors on the intakes.
- Tejas MK2 will get an approx 10mm increase in diameter for the increased air flow requirement of the F-414 (Cmdr Sukesh Nagaraj confirmed this as well). Too small a difference to be visible to the naked eye for us jingos. The spring mounted doors may also be bigger if needed
- When asked about the STR and ITR rates of the Tejas, he simply smiled and said "it's enough, let me put it that way". When I queried him further, asking about the ASR that the IAF had set based on the Mirage-2000 and MiG-29's STR and ITR, his smile vanished and he got serious. He said that when people look at 10 different brochures and come up with requirements, without looking at whether meeting all those requirements is even possible for ANY one fighter, they set themselves and the program up for failure. He was very frank about this, stating that even those brochure specs were just that- brochure specs that even those famed fighters sometimes don't meet. But they were taken as benchmarks anyway and then, without even bothering to look at the technological base in India, the ASR was prepared.
- He was full of praise for the handling of the Tejas. It's a true delight to fly and both he and Grp Cpt Suneet Krishna have tremendous confidence in the aircraft itself. He said that they both push the aircraft to its current limits without any worry since the FCS is very good. He did mention that they didn't push the Tejas Mk1 to its limits at the airshow but just wanted to display that it is maneuverable enough.
- When I asked him whether the Navy fully backs the NLCA program, he laughed and said "I'm here, aren't I?". So all in all, it appears that the IN is backing the program fully
- NP1 hasn't flown more than 4 flights because they're re-designing some of the structures on board. This is the additional strengthening required for handling the thumping that is a carrier landing. The landing gear is being re-designed since its overweight and NP2 is going to fly soon.
- I brought up the point he made at AI-2011 about how the Tejas should've started as a carrier variant and then gone on to the IAF variant. He seemed genuinely happy that someone had remembered that point of his and described the main issue with the NLCA NP1. The issue as he described it was that the LCA didn't have a central keel to pass the structural loads to, something he said that the AMCA won't face since it's a twin engine fighter. This meant that they had to put new attachment points which aren't the ideal solution and result in the bulky appearance of the current landing gear.
- I was going to ask him about the AMCA naval variant and he said that currently there is no plan for it.

At this point he had to leave and I was disappointed since I hadn't gotten to discussing anything about the Elta 2032/MMR, Litening LDP and the weapons on the Mk1 such as the Derby/Python V/R-77/Astra and Sudarshan..