LCA News and Discussions

saptarishi · Post by **saptarishi** » 29 Nov 2011 00:36

tsarkar wrote:^^ I recall PV3 had the radar installed. Might be mistaken though

lsp-3 has the hybrid mmr

merlin · Post by **merlin** » 29 Nov 2011 10:05

tsarkar wrote:^^ I recall PV3 had the radar installed. Might be mistaken though

Its a test bed for EW gear per Col. Ajay Shukla.

suryag · Post by **suryag** » 29 Nov 2011 11:31

Flight test update

LCA-Tejas has completed 1746 Test Flights successfully. (28-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-319,LSP1-67,LSP2-195,PV5-36,LSP3-46,LSP4-42,LSP5-50)

from

LCA-Tejas has completed 1741 Test Flights successfully. (25-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-315,LSP1-67,LSP2-195,PV5-36,LSP3-46,LSP4-41,LSP5-50)

IIRC, PV1/LSP1 was supposed to be geared up for EW role according to Broadsword. LSP3 onwards all LSPs carried the the radar

P Chitkara · Post by **P Chitkara** » 29 Nov 2011 15:15

Was going through the wiki on LCA and Bandar – made me wonder, what makes the Bandar have almost 50% greater combat radius. Can anyone explain it or provide links?

aditp · Post by **aditp** » 29 Nov 2011 16:17

^^^^Djinn tech

VinayG · Post by **VinayG** » 29 Nov 2011 17:45

P Chitkara wrote:Was going through the wiki on LCA and Bandar – made me wonder, what makes the Bandar have almost 50% greater combat radius. Can anyone explain it or provide links?

all the porkies and pandas have to do is press edit button in wiki and increase the range

Austin · Post by **Austin** » 29 Nov 2011 23:11

Troubles Slow Tejas Again

suryag · Post by **suryag** » 30 Nov 2011 00:36

^^^ old news right Sirjee ?

Kartik · Post by **Kartik** » 30 Nov 2011 01:01

Interesting picture that shows different stores configurations on the Tejas, from Livefist..

Image 1 shows 2 Derby BVR missiles with 2 R-73s.

Image 2 shows 2 PGMs with 2 R-73s and 1 LDP.

Image 3 has an asymmetric loadout with a single drop tank and 2 R-73s on the outermost pylons.

Image 4 shows a single LGB on the centerline and 2 R-73s

Indranil · Post by **Indranil** » 30 Nov 2011 01:09

If you look closely on the fourth pic, you will see the LDP too

Kartik · Post by **Kartik** » 30 Nov 2011 01:26

You're right Indranil. I didn't spot that.

VinayG · Post by **VinayG** » 30 Nov 2011 02:28

Austin wrote:Troubles Slow Tejas Again

Austin sahab
i think its time to privatize the Indian aircraft industry. HAL/NAL have become must be scrapped and should be sold to domestic private giants like TATA/MAHINDRAS. at-least PVT guys would have done some decent job by now

Austin · Post by **Austin** » 30 Nov 2011 10:37

Is this the case for every stores they carry every aircraft has to go through wind tunnel test ? Is that mandatory or just good to do it.

sohamn · Post by **sohamn** » 30 Nov 2011 10:55

^^^ It may be mandatory. If some store disturbes the air flow at some speed it might lead to serious issues in flight and might reduce/hamper the effectiveness of the fighter. So when they say the store is cleared for use it might include wind tunnel tests also.

Kartik · Post by **Kartik** » 30 Nov 2011 11:18

Austin wrote:Is this the case for every stores they carry every aircraft has to go through wind tunnel test ? Is that mandatory or just good to do it.

I suppose they need to do that to either verify CFD calculations or to spot any issues that may be too complicated for CFD analysis to bring to the fore. After all, in CFD analysis, quite a lot of assumptions are made to somewhat simplify the analysis in order to reduce the time taken to arrive at a solution.

suryag · Post by **suryag** » 30 Nov 2011 12:53

Flight test update

LCA-Tejas has completed 1747 Test Flights successfully. (29-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-320,LSP1-67,LSP2-195,PV5-36,LSP3-46,LSP4-42,LSP5-50)

from

LCA-Tejas has completed 1746 Test Flights successfully. (28-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-319,LSP1-67,LSP2-195,PV5-36,LSP3-46,LSP4-42,LSP5-50)

nikhil_p · Post by **nikhil_p** » 30 Nov 2011 20:05

P Chitkara wrote:Was going through the wiki on LCA and Bandar – made me wonder, what makes the Bandar have almost 50% greater combat radius. Can anyone explain it or provide links?

For YellCeeYay - Combat radius is the distance that the A/c can travel with stores and RETURN to base.

Bandar - One way ticket wonlee

SaiK · Post by **SaiK** » 30 Nov 2011 21:22

any such wind tunnel models for naval lca?

suryag · Post by **suryag** » 01 Dec 2011 13:07

Flight test numbers update

LCA-Tejas has completed 1750 Test Flights successfully. (30-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-322,LSP1-67,LSP2-196,PV5-36,LSP3-46,LSP4-42,LSP5-50)

From

LCA-Tejas has completed 1747 Test Flights successfully. (29-Nov-2011).
(TD1-233,TD2-305,PV1-242,PV2-211,PV3-320,LSP1-67,LSP2-195,PV5-36,LSP3-46,LSP4-42,LSP5-50)

arunsrinivasan · Post by **arunsrinivasan** » 01 Dec 2011 13:17

^^ looks like the pace of testing is picking up. That probably means the fuel leakage problem has been solved.

suryag · Post by **suryag** » 01 Dec 2011 13:23

The fuel leakage problem has been solved for a while, before the A2G tests were attempted IMO. I guess the latest tests are the ones that are happening in Goa for the AA missile firing. But may not be the case unless PV3 was installed with radar because only lsp3/4/5 were known to carry radar. If radar was not installed then they could be the regular flight envelope tests/hot-high altitude tests. How i wish they gave a test report every month stating what all they tested

keshavchandra · Post by **keshavchandra** » 01 Dec 2011 18:51

I got a LCA snap of Aero India 2011, under which it has a inlet on its back. I don't know what exactly it is?
Any guru may elaborate its purpose..

https://picasaweb.google.com/1173480868 ... 8037194786

krishnan · Post by **krishnan** » 01 Dec 2011 18:55

keshavchandra wrote:I got a LCA snap of Aero India 2011, under which it has a inlet on its back. I don't know what exactly it is?
Any guru may elaborate its purpose..
https://picasaweb.google.com/1173480868 ... 8037194786

Sorry, that page was not found.

keshavchandra · Post by **keshavchandra** » 01 Dec 2011 19:56

krishnan wrote:
keshavchandra wrote:I got a LCA snap of Aero India 2011, under which it has a inlet on its back. I don't know what exactly it is?
Any guru may elaborate its purpose..
https://picasaweb.google.com/1173480868 ... 8037194786

Sorry, that page was not found.

I used picasa from url posting. But I think it is password protected. may any one please help me out by giving a web link from where I may upload the image. Thanks.

tsarkar · Post by **tsarkar** » 01 Dec 2011 20:15

^^ The vents on either side allow airflow separated by engine inlet diverter to exit.

SaiK · Post by **SaiK** » 01 Dec 2011 20:30

not just lca, but world over fuel leaks are a big issue. wonder what is the design issue here?

rajanb · Post by **rajanb** » 01 Dec 2011 21:53

Saw a Tejas flying yesterday. I recognised it from the unique roar of its engine. Sounds like those cars you see on the road with the exhaust modified to give that exhilarating roar, and saw it gracefully turning and heading east. I do believe that there are things about its abilities which work well which we do not know about. All we hear about is its inabilities.

SaiK · Post by **SaiK** » 01 Dec 2011 22:59

good point rajanb, it is important to specify all its abilities and bring those to public visibility. it is important to keep that information public,. We all owe that to the nation to support this important piece of engineering work that would put us in a different league in the future.

Ravi Karumanchiri · Post by **Ravi Karumanchiri** » 01 Dec 2011 23:42

SaiK wrote:good point rajanb, it is important to specify all its abilities and bring those to public visibility. it is important to keep that information public,. We all owe that to the nation to support this important piece of engineering work that would put us in a different league in the future.

What military necessity is served by "specify all its abilities and bring those to public visibility."
Why is it important to keep that information public?

Quite the contrary: A stong case can be made that a platform's full capabilities must not be revealed until the outbreak of hostilities. Knowing the full operating performance of something like a rifle, is not nearly the same thing as knowing what an adversary's ships and planes and land combat systems can do.

When it counts, in time of war, what the military owes the nation, does not consist of back-slapping kudos for engineers.

Better to keep a few surprises in "war reserve".

Just my two paise.

SaiK · Post by **SaiK** » 01 Dec 2011 23:45

Ravi, you can show what stuff you are made of.. and need not show how you are made of. the same way.

The whats will give the necessary warnings to the enemies - can't you read that way?

AdityaM · Post by **AdityaM** » 01 Dec 2011 23:51

How do such small models substitute for a full size plane in a wind tunnel?

Also since the material used in model is all metal and small in size, how does it simulate the impact of the change in wing shape under the high speed?

saptarishi · Post by **saptarishi** » 01 Dec 2011 23:55

SaiK wrote:Ravi, you can show what stuff you are made of.. and need not show how you are made of. the same way.

The whats will give the necessary warnings to the enemies - can't you read that way?

right, show what you have even though that may not be as powerful as it is projected. hitler's nazi general erwin rommel paraded empty tanks without ammunition in world war 2 and made the allied forces to retreat believing that german army was huge and unconquerable. so he won east africa like this . sun tzu's art of war echoes similar stuff.

SaiK · Post by **SaiK** » 02 Dec 2011 01:08

saptarishi, that is an interpretation, however the focus area is throw open the abilities.

Ravi Karumanchiri · Post by **Ravi Karumanchiri** » 02 Dec 2011 01:12

^^^
QUESTION: What do you do when deterence fails?
ANSWER: Fight for your life, your way of life and everything else worth living for.
STAKES: ULTIMATE (No place for 'Tomfoolery'.)

Excess boasting of one's capabilities doesn't always work. It may have worked for Rommel, then and there; but if such tactics worked everywhere all the time, there would be no need for ammunition!

When it comes time to fight, it's always helpful to have a few tricks up one's sleeve, a few rabbits in pre-positioned hats and ideally, the element of surprise, or failing that, at least a degree of stealth. To have these critical things at the ready, when they're needed the most -- when the stakes are the highest -- this requires secrets, and lies, and subterfuge, misdirection, evasion and the like.

So yes, I agree with you to a degree: India need not play the weakling, but also, India should not reveal all her cards too soon.

PS: If the WWII Allies had something like a JSW (Joint Standoff Weapon), they would have tried a probing attack on Rommel's columns and his bluff would have been called. It worked for Rommel because there was no way for the Allies to know better, without risking too much of themselves. Modern warfare -- today's warfare -- has a very different calculus. Believe me, it's better to be better-armed than your adversaries expect of you (even if they expect you to have hidden strengths).

SaiK · Post by **SaiK** » 02 Dec 2011 01:17

It need not be open trump, unless asked for [need to show basis]. But, to play the game, one must declare it.. meaning you are telling the enemy, I have good set of cards.

I will win is different from I plan to win.

Vashishtha · Post by **Vashishtha** » 02 Dec 2011 02:27

How do such small models substitute for a full size plane in a wind tunnel?

Also since the material used in model is all metal and small in size, how does it simulate the impact of the change in wing shape under the high speed?

Every type of airflow can be identified by two parameters: Reynolds number(to do with viscosity of the flow) and mach number(speed of air wrt speed of sound under similar cond)... Engineers know what mach numbers and reynolds numbers to expect within the flight envelope and design wind tunnels which mimic airflows on the ground with the same numbers... Models of airplanes are scaled down to unit sizes and the data obtained from testing is then adjusted for the real size of the aircraft.

In the shortest and simplest way to put it...

NRao · Post by **NRao** » 02 Dec 2011 03:46

Some models also have embedded sensors.

When they ingest "smoke" they get a decent picture of what really can happen WRT flow too.

Indranil · Post by **Indranil** » 02 Dec 2011 04:08

Well explained in short ... but there are instances where the scaling down doesn't exactly match the real thing ... there was a good post sometime back about how the Su-27 was not supposed to be able to handle larger than 22 (24?) degrees AoA according to the wind-tunnel model and even a bigger 1/3rd scale model.

The legendary Viktor Pugachev however found that the plane could be pushed far beyond that to the amazement of everybody. Later it was found that the characteristic of the airflow was related to the length of the surface that it passed over.

I would try to find the piece ... it was a very interesting read.

None-the-less wind tunnel testing is the closest that you could get to the real thing.

SaiK · Post by **SaiK** » 02 Dec 2011 04:29

does the proportionality of scaling down matters? 1/3rd is better than 1/4th etc..?

Indranil · Post by **Indranil** » 02 Dec 2011 05:21

For that we will have to prove Reynolds wrong.

But there are some factors which cannot be modeled accurately in the wind tunnel. If one is interested one could read Dynamic similitude.