The Indian Tejas

[niteshkjain]

http://www.hindu.com/2008/06/08/stories/2008060855331100.htm

Move to seek Boeing help for LCA test programme

Ravi Sharma
The consultancy will need the clearance of the U.S. Department of State
It will help curtail number of sorties during flight test

It will shorten design, development phase of LCA

BANGALORE: The Aeronautical Development Agency (ADA) has moved forward to sign up with American aerospace major Boeing for consultancy on their Tejas Light Combat Aircraft’s (LCA) flight test programme. The tie-up suggests that the Bangalore based Indian defence laboratory is unable to, within the required time span, complete the testing on its own.

The tie-up which as per the United States laws concerning sale/consultancy of services and products in areas of defence will first have to be cleared by the U.S. Department of State. It is envisaged that the multi million dollar consultancy will shorten the design and development phase of the LCA.

The ADA sources told The Hindu that that the consultancy would help curtail the number of sorties that were to be flown in each phase of the LCA’s flight testing as the ADA attempts to obtain initial operational clearance (IOC) for the aircraft. The ADA’s latest revised schedule speaks of a 2010 deadline for the IOC.

The Boeing, with sufficient experience on flight test programmes like their F-18 Hornet, will provide the ADA with crucial inputs on which critical points of the flying envelope flight tests would have to be conducted.

This would avoid unnecessary flights and testing out every point of the flight envelope, saving on both costs, and even more importantly, time, enabling the ADA to compress the LCA’s flight test programme.

Under the agreement flight test data generated during flights undertaken by the Indian Air Force pilots attached to the National Flight Test Centre, would be handed over to the Boeing engineers for analysis. The Boeing would then advise the ADA what should be done, they said.

The consultancy is for a period of 42 months, with the option for the ADA to extend it if they need to.

The ADA over two years ago sent out a request for proposal to a number of global aerospace players including the Boeing, the Lockheed Martin, the Dassault and the Saab Gripen seeking this consultancy.

Official sources also said that the ADA had sought proposals from the Boeing and other aerospace players for help on the naval variant of the Tejas.

 

[niteshkjain]

LCA thrust issues

LCA thrust issues, all is open people are free to draw conclusions

All this talk about lack of thrust on Tejas got me thinking. So here is my analysis of LCA thrust.

ANALYSIS OF LCA/TEJAS THRUST WITH GE-404-IN20 ENGINE

INTRODUCTION

There has been number of articles appearing in media alluding to insufficient thrust in first lot of LCA/Tejas production aircraft with GE-404-IN20 engine. Most of these articles seem to reproduce misinformation spread by vested interests of import lobby. The objective of this analysis is to show that the first lot LCA/Tejas will be a very potent aircraft in terms of combat speed. We will use two other aircrafts for comparison to show this: Gripen C and Mirage 2000. The aircrafts were chosen because Gripen C is a contemporary light weight aircraft like LCA/Tejas, while Mirage 2000 was the gold standard used by IAF in specifying requirements for LCA/Tejas, though Mirage 2000 is a medium weight aircraft. We will use original manufacturer specification references as much as possible to prove our objective.

ANALYSIS

Per latest (2008) ADA specs [1], LCA/Tejas has an increased empty weight of 6500Kg and clean take off weight with 3000Kg of internal fuel, of 9500Kg. It can carry more than 4000Kg of external stores, but we will use 4000Kg for this analysis. The total weight is therefore equal to 13500Kg. GE-404-IN20 engine can develop maximum after burner thrust of 19000lb at sea level [2]. Though installed thrust in aircraft is not same as engine thrust, we will ignore it for this simple analysis. LCA/Tejas thrust to weight ratio at total weight is therefore 19000/(2.2*13500) ~= 0.6397.

Per Gripen specs [3], it has an empty weight of 6800Kg. Though Gripen C cannot carry 3000Kg of internal fuel, we will use 3000Kg of internal fuel for apples to apples comparison. We will also assume 4000Kg of external stores. The total weight is therefore equal to 13800Kg. Volvo Aero RM12 engine of Gripen C can develop a maximum after burner thrust of 18100lb [4]. Gripen C thrust to weight ratio at total weight is therefore 18100/(2.2*13800) ~= 0.5962.

Per Mirage 2000 specs [5], it has an empty weight of 7600Kg. We will assume 3000Kg of internal fuel and 4000Kg of external stores for an apples to apples comparison. The total weight is therefore equal to 14600Kg. M53-P2 engine of Mirage 2000 can develop a maximum after thrust of 21400lb [6]. Mirage 2000 thrust to weight ratio at total weight is therefore 21400/(2.2*14600) ~= 0.6663.

CONCLUSION

As can be seen LCA/Tejas will have better thrust to weight ratio than Gripen C which belongs to same light weight class. LCA/Tejas will have a thrust to weight ratio that is close to Mirage 2000. If the weight of LCA/Tejas can be reduced by 550Kg or alternately if the external stores is reduced by 550Kg, LCA/Tejas will have same thrust to
weight ratio as Mirage 2000, a medium weight aircraft. This shortage of performance, if it can be called as such, isn't bad considering it is just first production lot. One can also repeat this analysis for other internal fuel weights and external stores, but the results won't be dramatically different. Hence it can be concluded that first lot LCA/Tejas will be a very potent aircraft in terms of combat speed.


REFERENCES

1. http://www.flickr.com/photos/20125521@N02/2366848903/
2. http://media.bharat-rakshak.com/4475...ngine-info.pdf
3. http://www.gripen.com/NR/rdonlyres/A..._believing.pdf
4. http://www.volvo.com/volvoaero/global/en-gb/products/Aircraft+engines/RM12/RM12.htm?TAB=2
5. http://www.airramstein.nato.int/bold...mirage2000.pdf
6. http://www.snecma.com/IMG/pdf/M53-P2_Anglais.pdf


Mods, this time no wikipedia, sorry for last time using it

 

[vetrival]

Being offerred assistance is not considered 'fixed".



Being Helped and being offered is no where even close to considered as "fixed".



Ready to compte on Equal footing ? Are you serious? Lol. LCA is a prime example how ready to compete on equal footing Indian Aerospace Sector is !!



Yes and they told you personally that eh ?



You seriously need to tell that to DODO. The number of will you use says it all.

Which brings us back to the same point. LCA is NOT fixed and as of today it is no better then a trainer. So not a good idead to compare it with other aircrafts untill LCA is "fixed".

SNECMA is definately providing a solution to the engine problem and are confident that with their technological input the engine will be ready by 2009, infact they have offered to fit the dassault rafale with the kaveri engines if India opts for the said aircraft(part of the MMRCA deal).


The only reason the LCA does not have a definitive radar is that India is unwilling to just buy a radar instead they want full ToT on the radar(which they will get even if the LCA does not get an AESA radar since all the aircrafts except for the Rafale which are involved in the MMRCA deal have AESA radars and all the vendors are providing full ToT).


The LCA isn't just an advanced trainer it has already entered limited series production, the LCA has successfully itegrated with its projected armaments(R-73,R-77,Astra) and has test fired the R-73(short range air to air missile), it's avionics and the full authority digital engine control system are fully operational.


The reason for the delay of the LCA is not the supposed inefficiency of HAL or ADA but the political situation in the sub continent and the sanctions laid down on India due to it's nuclear tests(the said sanctions have been lifted).
Ofcourse I'am going to compare the LCA to other aircrafts(JF-17,Chengdu J-10), the reason is simple, the LCA will face direct competition from the aforementioned aircrafts hence a comparison between them and the LCA is justified.

 

[wp2000]

LCA thrust issues, all is open people are free to draw conclusions

All this talk about lack of thrust on Tejas got me thinking. So here is my analysis of LCA thrust.

ANALYSIS OF LCA/TEJAS THRUST WITH GE-404-IN20 ENGINE

...
Per latest (2008) ADA specs [1], LCA/Tejas has an increased empty weight of 6500Kg and clean take off weight with 3000Kg of internal fuel, of 9500Kg. It can carry more than 4000Kg of external stores, but we will use 4000Kg for this analysis. The total weight is therefore equal to 13500Kg.
...

I think you first need to clearly define what all these weight figures mean, otherwise your reasoning may not be accurate.
Here's a rough understanding of weight figures according to my readings of chinese materials

1. Structural Empty Weight: this is the basic plane frame weight, no engine, no weapon, no accessorries, no fuel etc, purely the structure. As an example, I remember F16A's Structural Empty Weight is 3600kg (very roughly figure)

2. Empty Weight: Structure Weight plus all the fixed components, like engine(s), avionics etc... F16A's figure is 7100kg, roughly. AND I believe LCA's empty weight is 6500kg. This should be what the Designger delivers.

3. Delivered Empty Weight: Empty weight plus all the misc sundry stuff, like lubricants and importantly 2-4 hundred kgs of fuel. Basically with all these stuff, the plane should be able to conduct all the ground activities. This is usually what the Manufacturer delivers to the Airforce.

4. Minimum Usage Weight: No3 plus Pilot weight, 40% fuel, and gun ammunitions. This is what PLAAF cares about because it's their starting point for calculation. But I believe this is where main confusion starts, because even the manufacturer may not know the exact process of the weight calculation used by PLAAF, e.g. whether at least a pair of SRAM and their pylons will be included or not etc...

5. from here on there are quite a few weight terms as well but for the sake of discussion, I don't want to go into them.

For LCA,

If we take 6500kg as empty weight, what is the definition of Clean Take Off Weight? 6500+How much fuel?+Pilot weight+Misc sundry items?+gun ammunitions?+?=9500kg

IMO, this is only the first step if you want to compare with other planes. For plane to fly at a certain speed, to a certain range, with a certain payload, thrust is only one of the important factors. You can't simply say why Gripen can do this and LCA must be able to do it, although therotically you can say, with enough thrust you can make a brick to fly as a bird. In reality you just can't.

 

[Aliph Ahmed]

LCA needs new engine to be worthy of combat

New Delhi, June 5: The home-grown Tejas Light Combat Aircraft (LCA), which is set to be inducted in 2011, will not be able to fly with a full-weapon load and will also need a new engine—instead of the Kaveri engine—to meet the minimum requirements for fighter aircraft drawn up by the Indian Air Force (IAF). To accommodate these modifications, the planes will also need to be redesigned.

In what could be a deathblow to the indigenous fighter programme, the Ministry of Defence (MoD) has conceded that the first lot of planes to enter service will not only carry a limited load of weapons but will also have a restricted ‘angle of attack’, making them unsuitable for aerial combat.

The primary reason for the problem is the lower thrust provided by the GE 404engine powering the aircraft. While plans to develop a newer engine are under discussion, there is no scope for improvement at least for the first lot of 40 aircraft, of which 20 have already been ordered by the IAF. “There is no way that the first 40 aircraft will have any other engine than the GE 404. The engine gives a power of 80-85 Kilo Newton while the IAF requires them to have a capability of 95-100 Kilo Newton,” a top MoD source said, adding that the current thrust provided by the engine limits the angle of attack — a measure of the maneouverability of the aircraft—to 17 degrees against the IAF’s minimum requirement of 21 degrees. This makes the fighter unsuitable for aerial combat, especially given that neighbouring countries already possess more agile fighter planes.

With the IAF not willing to introduce any more such ‘limited’ fighters, plans are afoot to give the LCA a new engine with greater thrust. However, this would also require a complete redesign. “To put in a new engine, like the GE 414, with this capability, the existing structure of the aircraft will have to be modified. This would need design changes that will take another 3-4 years,” the source said.

However, India is yet to decide whether to go in for a completely imported engine or jointly develop an engine with a leading international player. With the Kaveri engine making little headway, India is planning to rope in manufacturers like General Electric (US), Snecma (France), Rolls Royce (UK) and NPO Saturn (Russia) for the project

http://www.indianexpress.com/story/319117.html

REALITY = All bets are off on LCA untill a new engine is find.

Beautifully painted 28 planes that would be participating in National Parade Days but incapable of fighting.

I stand corrected that as of today and in immediate foreseeable future, LCA is no better then a trainer aircraft.

 

[Salty Dog]

LCA needs new engine to be worthy of combat

New Delhi, June 5: The home-grown Tejas Light Combat Aircraft (LCA), which is set to be inducted in 2011, will not be able to fly with a full-weapon load and will also need a new engine—instead of the Kaveri engine—to meet the minimum requirements for fighter aircraft drawn up by the Indian Air Force (IAF). To accommodate these modifications, the planes will also need to be redesigned.

In what could be a deathblow to the indigenous fighter programme, the Ministry of Defence (MoD) has conceded that the first lot of planes to enter service will not only carry a limited load of weapons but will also have a restricted ‘angle of attack’, making them unsuitable for aerial combat.

A restricted angle of attack may also disfavorably restrict the Tejas for carrier operations.

 

[Aliph Ahmed]

I have been following LCA for so long that it is not even funny anymore. Its desried angle of attack (AoA) was 26 degrees.

Last year:

From HAL's in-house magazine obtained at the Aero India 2007, LCA's test status in clean configuration was:

At 15 km altitude having an angle of attack of 20 degree pulling 5.4g at Mach 1.4 !!!

So instead of AoA increasing to desired 26 degrees, it has actually decreased to 17 degrees after loading up. (Even that is in god knows what form of configuration)

I dont wish to mock DODO. The experience they learned is valuable, however, A failed design can only go so far.

LCA is no better then a trainer. Like WP2000 said, with more thrust, even a brick can fly like a bird. DODO seems to be trying to do just that.

 

[kay_man]

to aliph and also to every one else,

as mentioned by someone erlier the ge-404 weighs only about 1000 kgs.
the 2000 kg weight increase is not due to the engine but mostly due to other technology additions like EW pods , laser targeting pods, better radar etc ,etc, etc...the list is endless.....A SIGN OF A TRUE MULTIROLE FIGHTER .
the airforce updates its requirements in order to keep up with the latest cutting edge technology....
THATS WHY THE WEIGHT INCREASE...so that even if the lca comes out in 2012 it will still incorporate all the latest tech available then .

engine thrust..(dry thrust)
GE-404.....81 kN
GE-404 IN20..........83 kN
KAVERI...............89 kN
although the ge engines are said to be underpowered..which im not certain of (coz all assumptions are based on one anonamus report) . it wont matter anyway . with french snecma helping out with kaveri it will be ready soon with complies with the thrust ratio . if miraculously it gets ready earlier then it will surely be incorporated in the 1st 20 planes as well...remaining ge engines can be used as spare parts

i dont see whts there to panic about .

 

[SABRE]

I have been following LCA for so long that it is not even funny anymore. Its desried angle of attack (AoA) was 26 degrees.

Last year:

From HAL's in-house magazine obtained at the Aero India 2007, LCA's test status in clean configuration was:

At 15 km altitude having an angle of attack of 20 degree pulling 5.4g at Mach 1.4 !!!

So instead of AoA increasing to desired 26 degrees, it has actually decreased to 17 degrees after loading up. (Even that is in god knows what form of configuration)

I dont wish to mock DODO. The experience they learned is valuable, however, A failed design can only go so far.

LCA is no better then a trainer. Like WP2000 said, with more thrust, even a brick can fly like a bird. DODO seems to be trying to do just that.

Whats DODO? Do you mean DRDO (Defence Research and Development Organization --- of India) ?

 

[aaaditya]

Whats DODO? Do you mean DRDO (Defence Research and Development Organization --- of India) ?

in case you havent noticed ,he's been making these comments for quite some time,it is no longer funny and is now becoming very offensive and irritating,he should show some respect to a professional organisation,and if he cannot then atleast he should not make such comments.

iam realy surprised that it took you moderators so long to notice it ,i hope atleast now you guys act on it and give aliph ahmed some advice.

 

[suryaaa]

With french snecma helping out with kaveri it will be ready soon with complies with the thrust ratio . if miraculously it gets ready earlier then it will surely be incorporated in the 1st 20 planes as well...remaining ge engines can be used as spare parts

i dont see whts there to panic about .

kay i dont think that there will be any change in the proposed initial batch of LCA.Which i came across in "BR" .Well it will certainly be a boost for LCA program if kaveri makes it before the first batch ( one can only hope).Also i heard that due to the lack of thrust from GE 404 engines Lca will carry only limited number of arsenal.A serious issue there.

 

[Aliph Ahmed]

Whats DODO? Do you mean DRDO (Defence Research and Development Organization --- of India) ?

Thank you for the correction Sabre. I will use DRDO for future references.



While plans to develop a newer engine are under discussion, there is no scope for improvement at least for the first lot of 40 aircraft, of which 20 have already been ordered by the IAF. “There is no way that the first 40 aircraft will have any other engine than the GE 404. The engine gives a power of 80-85 Kilo Newton while the IAF requires them to have a capability of 95-100 Kilo Newton,” a top MoD source said, adding that the current thrust provided by the engine limits the angle of attack — a measure of the maneouverability of the aircraft—to 17 degrees against the IAF’s minimum requirement of 21 degrees. This makes the fighter unsuitable for aerial combat,

http://www.indianexpress.com/story/319117.html

As of today, First lot of 40 LCA in its current form is no better then a trainer.

 

[SABRE]

in case you havent noticed ,he's been making these comments for quite some time,it is no longer funny and is now becoming very offensive and irritating,he should show some respect to a professional organisation,and if he cannot then atleast he should not make such comments.

iam realy surprised that it took you moderators so long to notice it ,i hope atleast now you guys act on it and give aliph ahmed some advice.

You should have pointed it out. It takes long cause sometimes we [or at leasr me] end up skipping threads in a hurry. Bring it to PM.

 

[Aliph Ahmed]

Pure delta wing tailless aircrafts are out of date. Simple as that, they are simple to design, but require high thrust/weight ratio, hence the great amount of fuel is used up relatively quicker. The Mirage 3/5/2000 or LCA are without canards, tail less, pure delta winged fighter jets and this configuration is not ideal with regards to manoeuvrability at low-altitude/speed flights, which induces high drag on the low-aspect ratio, high area wings, this causes delta-winged aircraft to 'bleed off' energy very rapidly, a disadvantage in combat and dog fighting, to counteract this drag to some extent, delta winged air crafts require a very power full engine with very high thrust-to-weight ratio,

LCA is originally intended to serve as an air superiority aircraft, but a simulation of Kaveri engine failed its high-altitude tests in Russia in 2004,even thou the thrust-to-weight ratio is quite high compared to JF-17s Russian counterpart. The LCA engine failed to maintain a high thrust to counter the drag created by the wing loading in high g’s banked manoeuvres.

Pure delta winged tail less aircraft has historically been hard to predict with their undesirable characteristics at high AOA since the days of the XF-92 the very first delta wing aircraft. The Indian LCA also has another feature, the wings are twisted, usually to stop TIPSTALLING, which is known as WASHOUT, results of such features are reduced AOA, most of the modern delta winged fighter jets use a combination of front canards and delta wings such as the Eurofighter, Saab grippen and J-10, to provide extra lift at high AOA.

Pure delta wing aircrafts have a number of limitations. Delta-winged aircraft have a long take-off run, since flaps are not practical as they would simply force the nose down; high landing speed; limited manoeuvrability; and suffer from buffeting at low altitude, due to the large wing area and resulting low wing loading. However, the delta is a simple and pleasing design, easily built and robust, capable of high speed in a straight line, and with plenty of space in the wing for fuel storage. Recon aircraft..(FAS.ORG)

Pure Delta wing aircrafts are more suited to high altitude supersonic cruise and reconnaissance. In LCA General electric F404 engine is a choice at the moment. Until LCA is cleared for FOC any assumptions on its air superiority would be pure fanciful speculation, it could see the design radically modified to reduce drag and engine load at high AOA. It is also true that pure delta wing aircrafts has poor rear visibility. The notion that future dogfights will only be beyond visual range is not true, given the speed aircrafts travel there is absolutely no proof that aircrafts will never be within visual range at some point hence the sophisticated T/V sidewinders developed e.g. AIM-9X, and cannons deployed.

Also, not to mention that kill probablity of a BVR missile fired at long range is very ineffective. LCA will have to come close and this is where all bets are on manouverability. Something LCA lacks in its current form and in the immediate forseeable future.

Disclaimer: Some comments are taken from the discussion I have had with an active PAF pilot.

 

[Salty Dog]

Pure delta wing tailless aircrafts are out of date.

Until LCA is cleared for FOC any assumptions on its air superiority would be pure fanciful speculation, it could see the design radically modified to reduce drag and engine load at high AOA. It is also true that pure delta wing aircrafts has poor rear visibility. The notion that future dogfights will only be beyond visual range is not true, given the speed aircrafts travel there is absolutely no proof that aircrafts will never be within visual range at some point hence the sophisticated T/V sidewinders developed e.g. AIM-9X, and cannons deployed.

Also, not to mention that kill probablity of a BVR missile fired at long range is very ineffective. LCA will have to come close and this is where all bets are on manouverability. Something LCA lacks in its current form and in the immediate forseeable future.

Disclaimer: Some comments are taken from the discussion I have had with an active PAF pilot.

Hey mate, you seem to be going out of your way to discredit the LCA. Your observations on delta wing aircraft are baised towards the same end. The question is why?

 

[Aliph Ahmed]

Hey mate, you seem to be going out of your way to discredit the LCA. Your observations on delta wing aircraft are baised towards the same end. The question is why?

The current events clearly support my arguement. I also used FAS website as a reference to back up my statements. There is nothing that I made up. LCA as of right now is nothing more then a trainer and this is the reality.

I'd be glad if you correct me.

You know the fancy term FBW, DRDO boasts so much on LCA ? Let me tell you that LCA is not a Fully FBW as claimed. It still uses hydraulics and not a full electrical FBW. Only the pilot link between the control surfaces and flight stick is FBW rest is Hydraulicaly controlled (control surfaces are not electrically controlled).

Newer fighters, F-22, JSF, Eurofighter, FBW systems they are full electrical systems !

 

[niteshkjain]

http://www.khabrein.info/index.php?option=com_content

India to launch Light Combat Aircraft Tejas by 2010

NEW DELHI, June 8 (KUNA) -- In an effort to add firepower to its Air Force, Indias is developing -- Tejas-- a Light Combat Aircraft (LCA), which is expected to be launched by 2010. LCA was in the final stages of testing and by 2010 it was expected to be launched, a source in the Indian Defene Ministry told KUNA here Sunday. After LCAs are launched, the MiG-21 fighter jets of the Indian Air Force (IAF) would be gradually phased out, the source added. Tejas is being developed by Indias Defence Research Development Organisation. Tejas underwent hot weather flight trials at Air Force Station in the Western Indian city of Nagpur recently, the source said, adding, the trials were planned at Nagpur because of the high ambient temperature conditions prevailing there during this period. The aim of the trials was to check operation of the aircraft systems under high ambient temperature conditions of over 40 deg C, representative of the stringent conditions the aircraft would be expected to operate in, after induction into the IAF.

"All aircraft systems, specifically the avionics system, flight control system and air conditioning system of Tejas were tested extensively during the trials and functioned satisfactorily on ground as well in flight," the source said, adding, a total of seven flights of four hours duration were flown at Nagpur on two prototype aircraft PV2 and PV3. The tests included flights at 200 meters above the ground with a speed up to 1000 km per hour.

"It was the first time that the Tejas flew a non-stop distance of about 1, 000 km from Southern Indian city of Bangalore to Nagpur. This was possible due to the presence of external fuel tanks on the aircraft which were integrated recently. This was also the first time that the Tejas aircraft had been flown at such high ambient temperature conditions. A first look at the test data indicated that all the trial objectives were met satisfactorily," the source informed. The successful completion of the trial marked a significant step towards attainment of all important initials operational clearance and subsequent induction into the squadron service with the IAF. Tejas is now planned for delivering precision guided bombs in the deserts of Western Indian state of Rajasthan, later this year.

 

[niteshkjain]

I think you first need to clearly define what all these weight figures mean, otherwise your reasoning may not be accurate.
Here's a rough understanding of weight figures according to my readings of chinese materials

1. Structural Empty Weight: this is the basic plane frame weight, no engine, no weapon, no accessorries, no fuel etc, purely the structure. As an example, I remember F16A's Structural Empty Weight is 3600kg (very roughly figure)

2. Empty Weight: Structure Weight plus all the fixed components, like engine(s), avionics etc... F16A's figure is 7100kg, roughly. AND I believe LCA's empty weight is 6500kg. This should be what the Designger delivers.

3. Delivered Empty Weight: Empty weight plus all the misc sundry stuff, like lubricants and importantly 2-4 hundred kgs of fuel. Basically with all these stuff, the plane should be able to conduct all the ground activities. This is usually what the Manufacturer delivers to the Airforce.

4. Minimum Usage Weight: No3 plus Pilot weight, 40% fuel, and gun ammunitions. This is what PLAAF cares about because it's their starting point for calculation. But I believe this is where main confusion starts, because even the manufacturer may not know the exact process of the weight calculation used by PLAAF, e.g. whether at least a pair of SRAM and their pylons will be included or not etc...

5. from here on there are quite a few weight terms as well but for the sake of discussion, I don't want to go into them.

For LCA,

If we take 6500kg as empty weight, what is the definition of Clean Take Off Weight? 6500+How much fuel?+Pilot weight+Misc sundry items?+gun ammunitions?+?=9500kg

IMO, this is only the first step if you want to compare with other planes. For plane to fly at a certain speed, to a certain range, with a certain payload, thrust is only one of the important factors. You can't simply say why Gripen can do this and LCA must be able to do it, although therotically you can say, with enough thrust you can make a brick to fly as a bird. In reality you just can't.

Hey I had given references for the points and if you see according ADA specs it is 6500kg empty weight + 3000kg fuel

 

[kay_man]

re

kay i dont think that there will be any change in the proposed initial batch of LCA.Which i came across in "BR" .Well it will certainly be a boost for LCA program if kaveri makes it before the first batch ( one can only hope).Also i heard that due to the lack of thrust from GE 404 engines Lca will carry only limited number of arsenal.A serious issue there.

dear suryaa,
dont take every bit of news that you find on the net seriously ,coz many of them are posted by anonymous sources and sometimes just to create controvercy .

The jas gripen weighs 6600 kgs is powered by ge-404 engines delivering a thrust of 81 kN
then how can the LCA be underpowered when it weighs a bit less than the gripen and is powered by ge-404 IN20 which delivers a thrust of 83 kN ??

the news about DRDO looking for a MORE powerful engine is the only confirmed news about the LCA (which came in all newspapers ) but they did not mention why they are looking for a more powerful engine ....and it has just sparked more controvercies and speculations .

if there was such a big problem, there wud have been an outcry from the IAF...dont you think ?

 

[Aliph Ahmed]

to aliph and also to every one else,

although the ge engines are said to be underpowered..which im not certain of (coz all assumptions are based on one anonamus report) . it wont matter anyway . with french snecma helping out with kaveri it will be ready soon with complies with the thrust ratio . if miraculously it gets ready earlier then it will surely be incorporated in the 1st 20 planes as well...remaining ge engines can be used as spare parts

i dont see whts there to panic about .

Please see post number 225 on this very thread's page 15 and enlighten yourself that no engine other then GE 404 will be introduced before the lot of 40 LCAs. Which will be incapable of participating in any combat.

What is there to panic about? There is everything to panic about. You will have 40 odd underpowered aircrafts unable to participate in combat.