LCA News and Discussions

KrishG · Post by **KrishG** » 23 Jun 2011 22:09

Mk-2 model's undercarriage.

Mk-1 model's undercarriage

Indranil · Post by **Indranil** » 23 Jun 2011 23:18

yes, we had a discussion on the changes in the under carriage during AI 11.

This should have been one of the choices available. Another choice could have been to keep the sleek underbody of MK 1, adding a wing body blend at the bottom, moving the under carriage outward and accommodating the wheel in a flat position inside the blend in the stow away position.This change would have been akin to the Gripen NG changes. But then Gripen NG made a bulb out of it because they wanted to increase internal volume. We are already increasing the length and hence increased the internal volume. We could thereby have had a much smoother and sleeker blend (like in the Rafale). What's more since we are increasing volume in the middle, we could have moved the air brakes near the CG ( I know there is talk about using the MLG primary door as the airbrake).

My question is if an aam abdul like me can see this, the engineers at HAL would have DEFINITELY know this. Then why did they choose the option they chose. Austin sahab gave one possibility of reducing work. Could there be any aerodynamic/structural/economic explanation also?

Kartik · Post by **Kartik** » 23 Jun 2011 23:51

indranilroy wrote: Why do you have to merge the wing with the air inlet when they are not matched. Smoothen the join from the diffuser along the wing join.

It looks fairly simple. And no it would not involve a lot of testing.
There are questions about wave drag (which is am issue in MK I). There are questions about fabrication but not about a huge redesign.

Indranil, your point is very interesting. A better wing-body blending at the bottom is definitely possible, and possibly (we can only guess since we have no access to wind-tunnel data) desirable as well. And like you said, it isn't a big change at all, with some manageable OML changes.

Kartik · Post by **Kartik** » 24 Jun 2011 00:02

raajneesh wrote: They planned this blending well ahead during planning stage(paper design stage). That's why today, one can see them in reality. Also, their first prototypes didn't have much of blending because new design features are added in increments in prototypes, but they are designed and thought in advance.

You can't just design a plane(LCA) and 15 years later after IOC, say, "lets blend the wings now and add some fuel in internal vaccum". It doesn't work that way. Such features have to be accomodated during initial design stages. LCA didn't have such plans.

Also, in 1980's noone thought of adding vaccum and fuel in the body. That was never accomodated/incporated into LCA's design. So, it can't just happen now without a full redesign.

So you're saying that if the wing-body blending wasn't done at the initial design stage itself then it cannot be done? Not true at all. This is a minor OML change and if wind tunnel and CFD analysis prove that improved blending at the bottom helps in reducing transonic drag, then it is definitely possible to make this change for Tejas Mk2, which is currently in detailed design phase.

And the fact is that the Tejas Mk2 was conceived specifically to address design and thrust shortfalls seen on the Tejas Mk1- there have been several changes made to the Tejas Mk1 OML as well as a fuselage plug added to increase its length. All these are being addressed currently, so IF such a wing-body blending is desirable then it CAN be done.

BTW, what the hell is "Also, in 1980's noone thought of adding vaccum and fuel in the body" ? Makes no sense whatsoever.

suryag · Post by **suryag** » 24 Jun 2011 00:05

Guys nothing wrong in mailing your inputs to ADA engineers

http://www.ada.gov.in/mk2.htm

Shri H Siddesha Project Director PS & LCA Mk II [email protected]
http://www.ada.gov.in/contact.htm

Bala Vignesh · Post by **Bala Vignesh** » 24 Jun 2011 00:12

Karthik Sir,
Could you kindly give the expansion of OML???

Kartik · Post by **Kartik** » 24 Jun 2011 09:04

sorry, OML stands for Outer Mould Line- that is the outer surface geometry.

SaiK · Post by **SaiK** » 24 Jun 2011 09:12

http://history.nasa.gov/SP-468/p243c.jpg
http://history.nasa.gov/SP-468/ch10-3.htm

Ref the pic inlet design c.. that was actually I meant by blending inlet and wings, and helping in supercruise.

and per draken http://forums.bharat-rakshak.com/postin ... &p=1115471
-----

http://www.aviationweek.com/aw/generic/ ... 221350.xml India hopes to develop stealth technologies indigenously. “We are looking at stealth features even for the LCA,” the official says. “We believe it can be developed here.”

That is interesting... so we can expect the stealth version of LCA in Mk3.

NRao · Post by **NRao** » 25 Jun 2011 06:08

Sure, MK3 can be a dynamite plane.

I would rather put more effort or resources into the AMCA.

Putting more resources into the LCA does not make the ROI any better.

Manish_Sharma · Post by **Manish_Sharma** » 25 Jun 2011 06:52

N Rao, what does ROI means?

SaiK · Post by **SaiK** » 25 Jun 2011 07:10

Aana-Jaana ke nivesh

Manish_Sharma · Post by **Manish_Sharma** » 25 Jun 2011 07:39

^^Dhanyawad SaiK!

Suppiah · Post by **Suppiah** » 26 Jun 2011 07:27

Not sure if posted earlier...Air Chief Naik on various matters incl. Tejas...

Tejas took us 20-21 years to reach this stage but over the last two years I have seen that we have reached a very good stage and there is light at the end of the tunnel. And I'm very very positive Tejas will be inducted into the Air Force. We have already given the initial operational clearance, now the squadrons will slowly come and start operating these aircrafts. It will take a couple of years for these aircraft to get full operational clearance. During this time, the phase two build-up is also going on with the actual engine which is a GE-414 engine which has been decided. Thereafter, the Tejas will have the engine and we will have 6-7, if not more, squadrons of the Tejas class of aircraft. Now all the people who have flown this aircraft swear by it, it's a wonderful aircraft. Of course, it is not in the fifth-generation class but I would call it a MiG-21++, with some latest technologies, with the latest collaborations an excellent aircraft to fill in the gap in our numbers which is there.

Read more at: http://www.ndtv.com/article/india/iaf-u ... -114743?cp

krishnan · Post by **krishnan** » 26 Jun 2011 07:31

It was posted in mil aviation thread

NRao · Post by **NRao** » 26 Jun 2011 08:02

Manish_Sharma wrote:N Rao, what does ROI means?

Return On Investments.

suryag · Post by **suryag** » 26 Jun 2011 10:08

Now all the people who have flown this aircraft swear by it, it's a wonderful aircraft

Very similar to what Dilip Cheta(IIRC?) said "those who have flown it dont criticise it, those who criticise it have not flown it."

UBanerjee · Post by **UBanerjee** » 26 Jun 2011 10:32

Manish_Sharma wrote:N Rao, what does ROI means?

Return on Investment

Parakram · Post by **Parakram** » 26 Jun 2011 15:12

Any news about LSP 6 ? the one which was experimental for high Angle of Attack(AOA)

raajneesh · Post by **raajneesh** » 27 Jun 2011 08:19

^^ LSP-6 is undergoing classified trials in Japan, in joint project. they are testing a new auto-pilot Take-off and Landing(ATOL) system on it.

sum · Post by **sum** » 27 Jun 2011 08:38

^^ Japan??

bmallick · Post by **bmallick** » 27 Jun 2011 09:08

raajneesh wrote:^^ LSP-6 is undergoing classified trials in Japan, in joint project. they are testing a new auto-pilot Take-off and Landing(ATOL) system on it.

sum wrote:^^ Japan??

Well sum, you fell for raajneesh's zero-sum-game.

sum · Post by **sum** » 27 Jun 2011 09:25

^^ He he...given the unbelievably large time of quiet from HAL ( even chaiwallahs have no comment on why soooo much delay), cant be surprised with anything!

Singh · Post by **Singh** » 27 Jun 2011 09:54

raajneesh wrote:^^ LSP-6 is undergoing classified trials in Japan, in joint project. they are testing a new auto-pilot Take-off and Landing(ATOL) system on it.

he he he Major aadha-bullah khan frm ISI read this post as part of his morning duties and alerted his superiors. All ISI sleeper agents in Japan were alerted to verify this claim.

SaiK · Post by **SaiK** » 27 Jun 2011 10:51

time to have some Sapporo.

Parakram · Post by **Parakram** » 27 Jun 2011 12:08

Any news about AESA for Tejas ?

chackojoseph · Post by **chackojoseph** » 28 Jun 2011 12:33

LCA Archives

Military engine Archive Mostly kaveri

chiragAS · Post by **chiragAS** » 05 Jul 2011 12:33

being used to just seeing the test flight info on ada webpage i had missied this
http://www.tejas.gov.in/
When did this went online...

Its really good ...

I remember since 2006 i used to see ada website and get pissed off for its slow loading.. now this one rocks..
someone should give even the ada website some makeover like the above one!

jai ho!!!

rajkumar · Post by **rajkumar** » 05 Jul 2011 12:53

chiragAS wrote:jai ho!!!

Simply brilliant. Dil Mange More

Rahul M · Post by **Rahul M** » 05 Jul 2011 13:00

excellent, this goes into the first post of this dhaga.

chiragAS · Post by **chiragAS** » 05 Jul 2011 13:05

I was of the impression that i was the only one who didnt know about this. seems like I broke the news so if adminullah permits can i start the lungi dance. (After all They have finally done what br folks were cribbing about since ages !)

Austin · Post by **Austin** » 05 Jul 2011 13:09

FUTURE DEVELOPMENT
Tejas Mark 2 - Featuring more powerful General Electric F414-GE-INS6 engine with 98Kn thrust and refined aerodynamics. The Mark 2 is being developed to meet the Indian Air Staff requirements.

Neela · Post by **Neela** » 05 Jul 2011 13:17

Wow!
Pics section has some that I have never seen!
Fantastic videos on AI 2011

Sent a congratulatory note to ADA for the website

Parakram · Post by **Parakram** » 05 Jul 2011 13:28

Austin wrote:FUTURE DEVELOPMENT
Tejas Mark 2 - Featuring more powerful General Electric F414-GE-INS6 engine with 98Kn thrust and refined aerodynamics. The Mark 2 is being developed to meet the Indian Air Staff requirements.

What are specification of the engine ? 98KN is max thrust ? I read from wikipedia that it has 120 KN max thrust.
Not able to find any specifications on GEs website either.
Can someone throw some "Roushni" ?

Austin · Post by **Austin** » 05 Jul 2011 13:31

Its 98 Kn as they mention it on their website , 120 kn is impossible unless they do some magic with the core.
The confusion was caused when it was mentioned the engine selected has the highest thrust of 414 , so some one thought it was 120 kn.

Sriman · Post by **Sriman** » 05 Jul 2011 14:16

chiragAS wrote:being used to just seeing the test flight info on ada webpage i had missied this
http://www.tejas.gov.in/
When did this went online...

http://www.tejas.gov.in/specifications/weapons.html

R-77 is still listed.

Rahul M · Post by **Rahul M** » 05 Jul 2011 14:27

it's 98 kN F414, I don't know where the 120 kN rumour is coming from. the EPE was never mentioned wrt tejas AFAIK.

p.s. never trust wiki without confirmation.

suryag · Post by **suryag** » 05 Jul 2011 14:30

suryag wrote:Come Mid-June we can look forward to a website for Tejas from its makers then, until that we might have to wait for inaccurate/inadequate press releases.

Information that the website was coming onstream posted in this thread

Parakram · Post by **Parakram** » 05 Jul 2011 14:39

Rahul M wrote:it's 98 kN F414, I don't know where the 120 kN rumour is coming from. the EPE was never mentioned wrt tejas AFAIK.

p.s. never trust wiki without confirmation.

Check this link

http://www.geae.com/aboutgeae/presscent ... 01001.html

It says

"The F414-GE-INS6 is the highest-thrust F414 model".

What they want to convey here ?

Singha · Post by **Singha** » 05 Jul 2011 15:23

the EPE does not exist. maybe it will be IOCed around 2018 when F-18 gets its next huge MLU.

right now INS6 seems to be the highest thrust model in physical existence and ready for the fight.

SaiK · Post by **SaiK** » 05 Jul 2011 16:50

Finally a great website for Tejas begins. nice.

Hope to see the weapons and bombs firing videos soon.

--

Austin, that 120kN I think it was a bright wishful thinking. But it would be something to attempt for kabini, and come out with a decent wet 100kN wala.