LCA News and Discussions

AdityaEngineer · Post by **AdityaEngineer** » 28 Sep 2011 18:09

Team Tejas Performing Tests in Full-Form.Yeepee!

neerajb · Post by **neerajb** » 28 Sep 2011 19:11

Marten wrote:What's the shiny bit that looks like an air vent on the side of the craft, just below where the fin joins the body.
Sorry, I cannot upload an image at this point, but it's shining bright enough to be noticed.

Never asked about it since I never felt the need. But I think that it is the exhaust (one on either side) of the air scoop which is used to cool the avionics.

Added later : Not sure where the exhaust of jet fuel starter is but this port seems too small for such an application.

Cheers....

SaiK · Post by **SaiK** » 28 Sep 2011 19:23

Did they increased the length of NP1, to accommodate the second seat?

If not, what did they compromise?

Pratik_S · Post by **Pratik_S** » 28 Sep 2011 19:56

Naval Tejas undergoes successful engine ground run

According to my sources the first flight is expected before the end of october.

suryag · Post by **suryag** » 29 Sep 2011 02:37

IS the ski-jump on the Viraat enough for the NP1 to take off ? Do we plan to add arrestor wires on the Viraat by any chance ? The Viraat as it is today is not very useful because of the limited numbers of the Sea Harriers.

Anurag · Post by **Anurag** » 29 Sep 2011 03:01

NP-1will never get anywhere close to the Viraat. It's going to do some trials on the flight deck of the Vikramaditya.

abhishek-nayak · Post by **abhishek-nayak** » 29 Sep 2011 09:56

suryag wrote:IS the ski-jump on the Viraat enough for the NP1 to take off ? Do we plan to add arrestor wires on the Viraat by any chance ? The Viraat as it is today is not very useful because of the limited numbers of the Sea Harriers.

my friend! Viraat is nothing more than floating junk today!!it should be retired immediately after the arrival of vikramaditya and vikranth

chackojoseph · Post by **chackojoseph** » 29 Sep 2011 10:13

suryag wrote:IS the ski-jump on the Viraat enough for the NP1 to take off ? Do we plan to add arrestor wires on the Viraat by any chance ? The Viraat as it is today is not very useful because of the limited numbers of the Sea Harriers.

Viraat metal is rotting. I had a closer look. it is unsafe for even people to walk let alone aircraft's fly on it. Its occupying nearly 2 berths in the dock and Navy is keen to dispose it.

Caution! This post is a Mistake.. Please ignore it. I mistook it for Vikrant.

narayana · Post by **narayana** » 29 Sep 2011 11:14

chackojoseph wrote:
suryag wrote:IS the ski-jump on the Viraat enough for the NP1 to take off ? Do we plan to add arrestor wires on the Viraat by any chance ? The Viraat as it is today is not very useful because of the limited numbers of the Sea Harriers.
Viraat metal is rotting. I had a closer look. it is unsafe for even people to walk let alone aircraft's fly on it. Its occupying nearly 2 berths in the dock and Navy is keen to dispose it.

OMG! IN is planning to keep it in service till 2015,may be atleast in ASW role.

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

Thanks Chacko ji thats not very heartening to hear

neerajb · Post by **neerajb** » 29 Sep 2011 12:11

A friend of mine was posted in Viraat and he painted a very dismal picture of living conditions. According to him leaking pipes and flooding of living quarters are common ocurrences and he wished never to go back there. FWIW.

Cheers....

chackojoseph · Post by **chackojoseph** » 29 Sep 2011 12:35

So sorry. I meant it for Vikrant. Sorry for the confusion. I regret.

Really sorry. Its the Telangana effect. No coals being transported, so the electricity situation and brief window to post stuff, let alone think.

rajanb · Post by **rajanb** » 29 Sep 2011 12:37

CJ: Too much of fb is not gud!

chackojoseph · Post by **chackojoseph** » 29 Sep 2011 12:42

rajanb wrote:CJ: Too much of fb is not gud!

Sorry loose moment.

As for Viraat. The fish is fine.

neerajb,

He must have gone before the refits. There was a massive overhaul. She is fighting fit.

chackojoseph · Post by **chackojoseph** » 29 Sep 2011 13:01

suryag wrote:IS the ski-jump on the Viraat enough for the NP1 to take off ? Do we plan to add arrestor wires on the Viraat by any chance ? The Viraat as it is today is not very useful because of the limited numbers of the Sea Harriers.

Yes it can. I am not sure of landing.

No arrestor wires on Viraat in future.

shiv · Post by **shiv** » 29 Sep 2011 18:11

Folks a little titbit about the SDRE LCA off BR news section. It files Bangalore Jamnagar unrefuelled with fuel to spare. That is 1800 km. Folks that should give the LCA a radius of at least 600 to 700 km plus loiter time over target. Or CAP for two hours, Very respectable.

Incidentally that covers all of Pakistan and most of Uttar Arunachal Pradesh (Tibet)

chackojoseph · Post by **chackojoseph** » 29 Sep 2011 18:30

^^^^ With stores?

RonyKJ · Post by **RonyKJ** » 29 Sep 2011 19:15

Uttar Arunachal Pradesh !!! I love that.
Now can BR put that on a map of India and post it as a sticky somewhere.
Come to think of it, do we have proper maps of India on BR?

SaiK · Post by **SaiK** » 29 Sep 2011 19:17

with out the drops?

shiv · Post by **shiv** » 29 Sep 2011 21:34

chackojoseph wrote:^^^^ With stores?

Three tons including drop tanks acc to the news report.

shiv · Post by **shiv** » 29 Sep 2011 21:41

RonyKJ wrote:Uttar Arunachal Pradesh !!! I love that.
Now can BR put that on a map of India and post it as a sticky somewhere.
Come to think of it, do we have proper maps of India on BR?

Well you need to do your duty and post holiday images of Mount Gopalankutty in Uttar Arunachal on Google Earth

shiv · Post by **shiv** » 29 Sep 2011 21:43

http://www.deccanherald.com/content/194 ... y-dec.html

Currently, Tejas has a capacity of taking a payload of three tonnes, including additional fuel for its sorties. Described as one of the most frugal aircraft ever to be inducted into the IAF, pilots said it could travel from Bangalore to Jamnagar without a stopover and have comfortable fuel after landing.

jai · Post by **jai** » 30 Sep 2011 01:29

neerajb wrote:A friend of mine was posted in Viraat and he painted a very dismal picture of living conditions. According to him leaking pipes and flooding of living quarters are common ocurrences and he wished never to go back there. FWIW.

Cheers....

Old news there. It is back in action after the last extensive refit when it's operational life was increased by more than 10 years as per it's co. It's a tough old goat And the only one with long pointy horns in this part of the world...more than capable of sending many ba(r)bars to the bottom of the Indian sea and Indian ocean.

SaiK · Post by **SaiK** » 30 Sep 2011 01:29

payload of three tonnes, including additional fuel for its sorties

okay, that means inclusive of the external fuel tanks, and confirms the math of takeoff - empty = 3 tonnes approx.

now, how much is remaining for weapons payload? 1.5 tonnes?

we should soon find a conformal LCA taking off in the future, when the uprated engine arrives.

srai · Post by **srai** » 30 Sep 2011 02:12

SaiK wrote:
payload of three tonnes, including additional fuel for its sorties
okay, that means inclusive of the external fuel tanks, and confirms the math of takeoff - empty = 3 tonnes approx.

now, how much is remaining for weapons payload? 1.5 tonnes?

...

That would depend on the mission profile.

In most cases (as observed in Vayu Shakti with Jaguars), IAF likes a combo of 2 x 1,000lb (or 450kg) bombs for strike missions with two 800 liters drop tanks.

Typical strike mission profile configuration:
* 2 x 800 liters drop tanks (~568kg each [800l * .711kg (at 60F)]) => 1,136kg
* 2 x 1,000lb bombs => 900kg
* 2 x SR-AAM (each 105kg) => 210kg
* 1 x Litening Pod => 200kg

Total ground strike payload: 2,446kg

For air-defense, this would probably be the typical load.

Typical CAP mission profile configuration:
* 2 x 800 liters drop tanks (~568kg each [800l * .711kg (at 60F)]) => 1,136kg
* 2 x MR-AAM (each 200kg) => 400kg
* 2 x SR-AAM (each 105kg) => 210kg

Total air-defense payload: 1,746kg

So from the above, it would seem a 3,000kg payload is quite sufficient for the LCA mk.1 for typical mission profiles.

SaiK · Post by **SaiK** » 30 Sep 2011 02:31

So, a light weight mini-brahmos[150km range/~800kg-1t] is a possibility for LCA then. I think we could have missions redefined by such a missile. ?

Kartik · Post by **Kartik** » 30 Sep 2011 05:17

did anyone notice that the N-LCA's nose wheel is no longer a twin-wheel configuration ?

Gurneesh · Post by **Gurneesh** » 30 Sep 2011 06:05

srai wrote:
Total air-defense payload: 1,746kg

So from the above, it would seem a 3,000kg payload is quite sufficient for the LCA mk.1 for typical mission profiles.

LCA could easily use some dual rail launchers for those R73's.

Indranil · Post by **Indranil** » 30 Sep 2011 08:11

Kartik wrote:did anyone notice that the N-LCA's nose wheel is no longer a twin-wheel configuration ?

This was from the day of the unveiling itself. I think it was marked out then.

AdityaEngineer · Post by **AdityaEngineer** » 30 Sep 2011 08:37

Guys The txt bk defination for AoA is 'Acute angle between the chord line of airfoil and the direction of flow of wind' this is what i studied in Second year mech engg. And its significance is that Coeff of lift = 2 pie sin(AoA) .But i am unable to understand what is the AoA Problem of Tejas being related (what is the improvement needed?)Please tell.

karan_mc · Post by **karan_mc** » 30 Sep 2011 09:12

User trials of Light Combat Aircraft to commence by end of year

rajanb · Post by **rajanb** » 30 Sep 2011 09:28

Todays Bangalore Mirror has an iinsignificant para stating the the LCA's weapons trial in Rajasthan has been completed significantly.

CJ, and details on this please?

Thanks

Shubham · Post by **Shubham** » 30 Sep 2011 09:33

AdityaEngineer wrote:Guys The txt bk defination for AoA is 'Acute angle between the chord line of airfoil and the direction of flow of wind' this is what i studied in Second year mech engg. And its significance is that Coeff of lift = 2 pie sin(AoA) .But i am unable to understand what is the AoA Problem of Tejas being related (what is the improvement needed?)Please tell.

As per my limited knowledge of Aerodynamics, the formula you have quoted is not correct for aerofoils.

Lift = 1/2 * Coeff of lift * density * IAS^2 * Surface Area

Now Coeff of Lift itself is dependent on several factors like AoA, Reynolds no, shape and condition of surface...

Coming to your original question, the guys testing the ac are just trying to figure out that the maximum AoA the ac can fly(at what AoA it stalls) is the same in practice as predicted during designing and simulations.

shiv · Post by **shiv** » 30 Sep 2011 09:36

AdityaEngineer wrote:Guys The txt bk defination for AoA is 'Acute angle between the chord line of airfoil and the direction of flow of wind' this is what i studied in Second year mech engg. And its significance is that Coeff of lift = 2 pie sin(AoA) .But i am unable to understand what is the AoA Problem of Tejas being related (what is the improvement needed?)Please tell.

There is no angle of attack problem. The IAF requires a particular value of angle of attack. But as the AoA is increased the aircraft could stall and crash if the airspeed falls below a specific value. So the LCA is software prevented from going above a certain value. Because of the risk of stalling and spinning,The LCA needs the installation of a special spin chute before higher angles of attack are tested to see how the aircraft behaves and then the plane certified for that increased AoA with or without further modifications (such as tweaking the FC software). LSP 6 will have/has this antispin parachute

If India already had 70 years of Aerodynamics experience under our belts we too could be doing what the Russians are doing. They have installed a spin chute on prototype no 3 of T-50 and will commence high-AoA trials. We do this at an SDRE rate because of zero prior data to work with and the extreme criticism and national handwringing if we have one accident.

We had zero experience of just how robust to make the NLCA landing gear and that is why it took so long. If we find that it is now stronger than needed there will be scope for future decreases in strength/weight.

Indranil · Post by **Indranil** » 30 Sep 2011 09:37

Shubham wrote:
AdityaEngineer wrote:Guys The txt bk defination for AoA is 'Acute angle between the chord line of airfoil and the direction of flow of wind' this is what i studied in Second year mech engg. And its significance is that Coeff of lift = 2 pie sin(AoA) .But i am unable to understand what is the AoA Problem of Tejas being related (what is the improvement needed?)Please tell.
As per my limited knowledge of Aerodynamics, the formula you have quoted is not correct for aerofoils.

Lift = 1/2 * Coeff of lift * density * IAS^2 * Surface Area

Now Coeff of Lift itself is dependent on several factors like AoA, Reynolds no, shape and condition of surface...

Coming to your original question, the guys testing the ac are just trying to figure out that the maximum AoA the ac can fly(at what AoA it stalls) is the same in practice as predicted during designing and simulations.

Also they are quite confident about the wing being able to handle the AoA.

They don't seem to be equivocal about the air intake.

Aditya_V · Post by **Aditya_V** » 30 Sep 2011 10:01

shiv wrote:http://www.deccanherald.com/content/194 ... y-dec.html
Currently, Tejas has a capacity of taking a payload of three tonnes, including additional fuel for its sorties. Described as one of the most frugal aircraft ever to be inducted into the IAF, pilots said it could travel from Bangalore to Jamnagar without a stopover and have comfortable fuel after landing.

Shiv but would not ferry ranges with drop tanks and flying at fuel efficient speed differ widely with Combat radius where maximum dry thrust, use of after burners plus sometimes lo-lo profile will be used. Even the F-15C has a ferry range of 4500KM but its combat range would be nearly half that.

But yes if compare with Mig-21, Mig 29, Mig 27 in IAF service, the range of LCA should be much much better giving a lot of flexibility to the IAF.

I think the PAF understands this that unlike 1971 when Hunters, SU-7B Mig 21 streched thier payloads to reach shorkot road, Sargodha and Peshawar that they were most reduced to straffing runs and rocket attacks, in any future conflicts IAF after Prithvi Brahmos strikes Jaguars, M-2000, SU-30 and LCA in service will turn up with heavy bomb shelter busting bombs which could take out the bulk of the PAF in a few hours.

I hope the US strictly enforces that F-16's facilities are given only to 1 or 2 airbases like Sargodha and Jacobobad.

Anther Tidbit from SHiv's link above from the Deccan herald.

The designated aircraft are the limited series production aircraft LSP-7 and LSP-8 and the ASTE will also train more pilots to test them.

Krishna said most of the weapons systems being integrated onto Tejas were approved, but there would also be some special weapons, details of which are classified information.

Shubham · Post by **Shubham** » 30 Sep 2011 11:44

Dear shivji and indranilroyji your posts have raised a few questions for me

1. They don't seem to be equivocal about the air intake
So you mean to say that while stalling the ac ( say in the level flight) the air intake might not allow the airflow to remain streamlined and resulting in possible compressor stall or engine surge ??
From what I have read the remedy (recovery actions) of both stall as well as engine surge is to anyhow increase ac speed which is by putting the ac in a dive , so even if that means that the air intakes needs to be fine-tunes for higher alpha, in the meantime the ac can safely be taken to the desired alpha and recovered.

2. Because of the risk of stalling and spinning
will a simple practice stall of a delta wing ac cause it to enter spin regimes ??
From the video of Vijeta posted in another thread, I deduced that entry into practice spin is similar to that of practice stall, just that there at 105 kts the controls are mishandled(whereas the stalling speed is ~98 kts in dirty).

Of course I am assuming that currently the pilots are not able to reach desired alpha in LCA even in level flight(due to above two reasons).

suryag · Post by **suryag** » 30 Sep 2011 12:01

Here is the article that rajanb refers to above
Saras will soar again

CLEARANCE FOR TEJAS BY YEAR-END
The Light Combat Aircraft (LCA) Tejas, which successfully cleared weapons trials in Rajasthan a couple of days ago, will obtain its Final Operational Clearance (FOC) from IAF by the end of 2011.

Dont read much into it because o the last claim(2011 FOC)

Meanwhile flight test update

LCA-Tejas has completed 1686 Test Flights successfully. (22-Sep-2011).
(TD1-233,TD2-305,PV1-242,PV2-208,PV3-295,LSP1-67,LSP2-178,PV5-36,LSP3-43,LSP4-41,LSP5-38)

LCA-Tejas has completed 1685 Test Flights successfully. (17-Sep-2011)
(TD1-233,TD2-305,PV1-242,PV2-208,PV3-295,LSP1-67,LSP2-178,PV5-36,LSP3-43,LSP4-40,LSP5-38)

Lalmohan · Post by **Lalmohan** » 30 Sep 2011 12:16

stall does not automatically mean spin
post stall spin is induced by the application of rudder to force the nose around and down and continue (to spin)
without any rudder (or other lateral force) the stall should recover in the same axis (nose down)

rajanb · Post by **rajanb** » 30 Sep 2011 12:19

Thanks Suryag.

a) I read somewhere else that LSP-6 & 7 will be handed over to the IAF by end 2011. The IAF will conduct user trials and the FOC will be end 2012, with one squadron based in Bangalore which will be moved to Sulur post FOC.
b) There seems to be only one flight the w/e 22 Sept. It seems not to reflect the shifting of A/C to Rajasthan for the weapons testing. Or, that has happened post 22nd Sept?