ADA Tejas (LCA) News and Discussions

[saik]

I have read the changes to be extension on the fuselage to accommodate more internal fuel, and some wing extensions.

 

[Zebra]

I beg to differ .
The change in Engine leads to change in structure in short everything.

The dimensional difference leads to the space taken up by the engine.
The difference in weight leads to change in load carrying ability of the parts.
Change in power leads to more rigid frame.

As per my knowledge it will be having larger fuselage which means more empty space that leads to variable centre of gravity (consumption of fuel).

So with that it leads to in one way or the other change in almost everything.

What we learn from MK1 is the steps taken to rectify to meet requirements which can be kept in mind while building MK2 for faster clearances.

If you don't mind, tell us the dimensional difference of both the engines. Please.

If there are any, then it will be news for me.

 

[Kunal Biswas]

The words are not mine, But Ex - Drdo chief Dr Saraswat ..

I beg to differ .The change in Engine leads to change in structure in short everything.

The dimensional difference leads to the space taken up by the engine.
The difference in weight leads to change in load carrying ability of the parts.
Change in power leads to more rigid frame.

As per my knowledge it will be having larger fuselage which means more empty space that leads to variable centre of gravity (consumption of fuel).

So with that it leads to in one way or the other change in almost everything.

What we learn from MK1 is the steps taken to rectify to meet requirements which can be kept in mind while building MK2 for faster clearances.

 

[sgarg]

People keep on jumping to conclusions (like Pulkit) here as there is too much disinformation against LCA Tejas. The vested interests (who profit from imports) have put out huge amount of misleading information in the press.

F414 is a drop-in replacement for F404. There are very few differences. We have discussed this here before.

 

[tejas warrior]

But i get sense DRDO/ADA looks quite confident now for MKII based on their experience gained on MKI.

Hope they can fly it by early 2017.

 

[karn]

According to that other blog that everyone here hates. The fabrication of the 1st tejas 2 prototype has started and will fly in 2017.
Also read the statement by Dr Avinash Chander that the fuselage on the tejas 2 will have composits not just on the wings like on the tejas 1 increasing composite content from 65 to 80 %.
All of this will require substantial work surely .

 

[Pulkit]

If you don't mind, tell us the dimensional difference of both the engines. Please.

If there are any, then it will be news for me.

I will look for a trusted source to state that and share the same (Volume is same for both the engines).

Till then just let me know you agree on the fact that to accommodate new engine structural changes are being made or not?

If that's true i need not to look for source.

 

[Pulkit]

The words are not mine, But Ex - Drdo chief Dr Saraswat ..

If the changes I pointed are there then the MK2 will need to go through all these tests again in future.

 

[Pulkit]

If you don't mind, tell us the dimensional difference of both the engines. Please.

If there are any, then it will be news for me.

Sharing links from what I think is acceptable.
The F414 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F414-Family.pdf

The F404 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F404-Family.pdf


If you can see the specs you will observe some changes .
I think that will be sufficient.

 

[ladder]

People keep on jumping to conclusions (like Pulkit) here as there is too much disinformation against LCA Tejas. The vested interests (who profit from imports) have put out huge amount of misleading information in the press.

F414 is a drop-in replacement for F404. There are very few differences. We have discussed this here before.

No, I don't think F-414 is drop fit. Fuselage has to be widened by 2 inches for F414.

 

[Kunal Biswas]

MK1 was designed around Kaveri Specs, Which is heavier than GE 404 IN and Similar to GE 414, The inlets were too design for +80Kn engine ..

The main difference will be MK2 is few cms longer than MK1, Rest is improved airframe both in material and aerodynamically reducing weight, within same dimensions ..

If the changes I pointed are there then the MK2 will need to go through all these tests again in future.

Sharing links from what I think is acceptable.
The F414 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F414-Family.pdf

The F404 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F404-Family.pdf


If you can see the specs you will observe some changes .
I think that will be sufficient.

No, I don't think F-414 is drop fit. Fuselage has to be widened by 2 inches for F414.

 

[Pulkit]

People keep on jumping to conclusions (like Pulkit) here as there is too much disinformation against LCA Tejas. The vested interests (who profit from imports) have put out huge amount of misleading information in the press.

F414 is a drop-in replacement for F404. There are very few differences. We have discussed this here before.

If you name me tag me too.
Instead of this hooobaal blaa blaa blaa.
Tell me where did i say anything wrong.

IS F414 and F404 100% match?
Is there no difference in there structure?
Is there no change not even the slightiest bit to fit it in?


I hate this whole idea of GE engines I would have loved to see Kaveri instead....

 

[Pulkit]

MK1 was designed around Kaveri Specs, Which is heavier than GE 404 IN and Similar to GE 414, The inlets were too design for +80Kn engine ..

The main difference will be MK2 is few cms longer than MK1, Rest is improved airframe both in material and aerodynamically reducing weight, within same dimensions ..

Sir I have some experience being designing very common parts for aircraft.
Here is my observation If i may ....

1mm change in dia of a hole drilled.
1mm difference in position of placement

leads to major design rework.

While manufacturing
little flaking or dent can lead to rejections.

Replacement of one part with similar part lets say a bracket leads to a fully thorough evaluation by stress strain and design team .
Even if just a small composition of material changes there is a huge cry.

and here we are talking about increasing composite % (CFRP+GF).
Fitting a different engine and that too when fuselage needs to be improved.
I said volume can be same but they cannot be identical and that makes a huge difference.

 

[Pulkit]

People keep on jumping to conclusions (like Pulkit) here as there is too much disinformation against LCA Tejas. The vested interests (who profit from imports) have put out huge amount of misleading information in the press.

F414 is a drop-in replacement for F404. There are very few differences. We have discussed this here before.

And one thing more dare not challenge my love for LCA.
I have been a hard core supporter of Tejas.
So you dare not point that finger towards me again.

Kindly don't get personal.
@admin if u may

 

[Kunal Biswas]

Regarding particulars, Must Pass various test and certifications ..

------

Their will be test flights, If i am not wrong NP-2 ( MK2 Navy ) is already going for various tests ..

But the point here is, Most of the test are already done via MK1, These things wont be repeated for MK2 ..

Above all, Dr Saraswat said this then there is a very good reason behind it ..

Sir I have some experience being designing very common parts for aircraft.
Here is my observation If i may ....

1mm change in dia of a hole drilled.
1mm difference in position of placement

leads to major design rework.

While manufacturing
little flaking or dent can lead to rejections.

Replacement of one part with similar part lets say a bracket leads to a fully thorough evaluation by stress strain and design team .
Even if just a small composition of material changes there is a huge cry.

and here we are talking about increasing composite % (CFRP+GF).
Fitting a different engine and that too when fuselage needs to be improved.
I said volume can be same but they cannot be identical and that makes a huge difference.

 

[Pulkit]

Regarding particulars, Must Pass various test and certifications ..

------

Their will be test flights, If i am not wrong NP-2 ( MK2 Navy ) is already going for various tests ..

But the point here is, Most of the test are already done via MK1, These things wont be repeated for MK2 ..

Above all, Dr Saraswat said this then there is a very good reason behind it ..

Kunal sir I totally get what you are trying to state.
but let me give a very bad example to present my point.
I make a base design and test it for alot of parameters then I go back to drawing board and make few changes .Can i straight away fly it.... No....

When we say Tejas MK2 it is a improved form of MK1 because it is based on it not because they are identical.

So MK2 is totally a new aircraft .

Aircrafts are designed around Engines and when engine varies everything varies.

Dr Saraswat point is that alot of effort that went in reaching IOC 1 and the IOC2 and now FOC will be used in form of experience and all these tests which happened
in so many phases can be completed in one go.

If the engine way a straight fit then improving only fuselage would not have been that difficult .

From my personal experience.

Due to a mis fit of head of a nut with bracket lead to change to entire frame when it came to assembly n installation.
In this case we are talking about a whole new engine.

 

[Zebra]

Sharing links from what I think is acceptable.
The F414 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F414-Family.pdf

The F404 Engine | Engines | Military | GE Aviation
http://www.geaviation.com/engines/docs/military/datasheet-F404-Family.pdf


If you can see the specs you will observe some changes .
I think that will be sufficient.

As we are talking about dimensional difference here.

Your own source tells the story, both the engine variants for India has no difference in length and diameter. Please check the red colour part.


1) The F414 Engine | Engines | Military | GE Aviation

Comparison

F414-INS6

Thrust Class (lb)..........22,000

Length (Inches) ..........154

Airflow (lb./sec) ..........170

Pressure Ratio .............9:1

--------------------------------------------------------------------


2) The F404 Engine | Engines | Military | GE Aviation

Comparison

F404-IN20

Sea Level/Standard Day

Thrust Class (lb)..........19,000

Length (Inches) ..........154

Airflow (lb./sec)...........153

Pressure Ratio .............28:1

----------------------------------------------------------------------------------------------


3) http://www.geaviation.com/engines/do...404-Family.pdf

F404 - IN20

Thrust class ..........19,000 lb ( 84 kN )

Length ..........154 in (391 cm)

Airflow ...........153 lb/sec (70 kg/sec)

Maximum diameter ..........35 in (89 cm)

Weight ..........2,365 lb (1,072 kg)

Inlet diameter ..........28 in (71 cm)

Pressure ratio.......... 28:1 (28:1)

-----------------------------------------------------------------------------------------


4) http://www.geaviation.com/engines/do...414-Family.pdf

F414-GE-400; F414G, F414-INS6 ---- English ( SI )

Thrust class ..........22,000 lb (98 kN)

Length ..........154 in (391 cm)

Airflow ..........170 lb/sec (77.1 kg/sec)

Maximum diameter ..........35 in (89 cm )

Inlet diameter ..........31 in (79 cm )

Pressure ratio ..........30:1 (30:1)

Thrust-to-weight class ..........9:1 (9:1)

 

[Pulkit]

Casper When the talk about maximum and minimum dimension is does not mean they are same.
I only shared these specs and i know them well.

But you very smartly ignored the Inlet diameter .
Weight difference.

I hope you agree on the point that they produce different power even if in your knowledge they are identical.
If yes
FYI
more power will lead to more stress /pressure on structures holding the engines.

which again leads to major structural change.

take a cone and a cylinder of same diameter and length .

Are they same?

I again repeat they have structural/dimensional changes.

As we are talking about dimensional difference here.

Your own source tells the story, both the engine variants for India has no difference in length and diameter. Please check the red colour part.


1) The F414 Engine | Engines | Military | GE Aviation

Comparison

F414-INS6

Thrust Class (lb)..........22,000

Length (Inches) ..........154

Airflow (lb./sec) ..........170

Pressure Ratio .............9:1

--------------------------------------------------------------------


2) The F404 Engine | Engines | Military | GE Aviation

Comparison

F404-IN20

Sea Level/Standard Day

Thrust Class (lb)..........19,000

Length (Inches) ..........154

Airflow (lb./sec)...........153

Pressure Ratio .............28:1

----------------------------------------------------------------------------------------------


3) http://www.geaviation.com/engines/do...404-Family.pdf

F404 - IN20

Thrust class ..........19,000 lb ( 84 kN )

Length ..........154 in (391 cm)

Airflow ...........153 lb/sec (70 kg/sec)

Maximum diameter ..........35 in (89 cm)

Weight ..........2,365 lb (1,072 kg)

Inlet diameter ..........28 in (71 cm)

Pressure ratio.......... 28:1 (28:1)

-----------------------------------------------------------------------------------------


4) http://www.geaviation.com/engines/do...414-Family.pdf

F414-GE-400; F414G, F414-INS6 ---- English ( SI )

Thrust class ..........22,000 lb (98 kN)

Length ..........154 in (391 cm)

Airflow ..........170 lb/sec (77.1 kg/sec)

Maximum diameter ..........35 in (89 cm )

Inlet diameter ..........31 in (79 cm )

Pressure ratio ..........30:1 (30:1)

Thrust-to-weight class ..........9:1 (9:1)

 

[Zebra]

Casper When the talk about maximum and minimum dimension is does not mean they are same.
I only shared these specs and i know them well.

But you very smartly ignored the Inlet diameter .
Weight difference.

I hope you agree on the point that they produce different power even if in your knowledge they are identical.
If yes
FYI
more power will lead to more stress /pressure on structures holding the engines.

which again leads to major structural change.

take a cone and a cylinder of same diameter and length .

Are they same?

I again repeat they have structural/dimensional changes.

Sir, first of all we don't know and even HAL also don't know which GE F-414 engine they gonna fit on mk2 aircrafts.

There are total four types of GE F-414 engines.

1) F414-GE-INS6

2) F - 414 Enhanced Durability Engine (EDE)

3) F - 414 Enhanced Performance Engine (EPE)

4) All new light weight GE- F-414 engine for Super Hornet Block 3 as part of "International Roadmap".


Second, GE F-404 and GE F- 414, they both are different variants of the same product line.

There will be some changes in them as there output are different. But still their overall size, dimension remain same and dry weight of F - 414 will be more (say....... xyz < 100 kg).

As GE 414 has better thrust, mk2's airframe has to be strong enough. But for that matter HAL have to re design entire new aircraft as mk2......?

I don't think so. But then you can correct me too.

 

[Zebra]

^^

Read it as ----> There are total four types of GE F-414 engines that HAL can try.