LCA News and Discussions

Dileep · Post by **Dileep** » 16 Dec 2010 07:49

A digital camera sensor (film too IIRC) does sense the IR. By the look of the spot, it seems unlikely to be an explosion.

Shine your TV Remote on your camera and see it light up.

shiv · Post by **shiv** » 16 Dec 2010 08:15

Dileep wrote:A digital camera sensor (film too IIRC) does sense the IR. By the look of the spot, it seems unlikely to be an explosion.

Shine your TV Remote on your camera and see it light up.

Dileep - it's this picture from Tarmak that shows earth and debris being thrown up by an explosion
http://3.bp.blogspot.com/_5sP7XwykNSM/T ... ture+4.jpg

Gurneesh · Post by **Gurneesh** » 16 Dec 2010 08:23

In all probability that bomb was a dud. It was mentioned that initially dummy bombs will be used (same weight sans the explosive or very less explosive).

As I said earlier, the laser spot will not be (should not be) more than some mm in diameter. The images presented seem to have been taken for a fair distance away. So, to capture the laser spot (infra red or visible) you would need to zoom in a lot. Plus all laser spots are circular (some nearly circular) in shape (until someone wants to do something fancy). So, unless one can identify such an artifact in the pictures, it is safe to assume that the pics give no info on the use of laser rangefinder/marker.

shiv · Post by **shiv** » 16 Dec 2010 08:39

Let's cut the speculation. That flash is from an exploding bomb. Here is an 5x enlargement of 2 pics from Tarmak's blog

Anujan · Post by **Anujan** » 16 Dec 2010 09:03

ramana wrote:Oh so its the Laser range finder making the bright spot. If so great job!

nachiket wrote:Ramana garu, the laser is in the infrared spectrum, not visible AFAIK. The bright spot is actually the beginning of the explosion.

Not saying it is laser, but IR can be picked up by cameras (and not by the human eye). You can photograph a TV remote and see it glowing in the photo.

SaiK · Post by **SaiK** » 16 Dec 2010 09:16

Okay, based on dileep, anujan posts and siv ji's second picture that shows pinkish ball we could say it is an IR signature.

.

Gagan · Post by **Gagan** » 16 Dec 2010 09:19

The bomb missed the target by a couple of feet?

BTW are we sure this is a LGB? If it was a LGB, this was fired from say 10+ Kms off!

abhik · Post by **abhik** » 16 Dec 2010 09:51

That red thing is definitely a flag.

SaiK · Post by **SaiK** » 16 Dec 2010 09:59

Yes it is.
http://4.bp.blogspot.com/_5sP7XwykNSM/T ... ture+2.jpg

Then Gagan is right as well. If that is so, then it can't be a laser guided drop!

vina · Post by **vina** » 16 Dec 2010 10:01

Gagan wrote:The bomb missed the target by a couple of feet?

BTW are we sure this is a LGB? If it was a LGB, this was fired from say 10+ Kms off!

Shiv wrote:Let's cut the speculation. That flash is from an exploding bomb. Here is an 5x enlargement of 2 pics from Tarmak's blog

From the pictures, it does look like a bulls eye. The bomb didnt land on top of the flag, but it hit the base or atleast a part of the base of the cement pyramid target on which the flag was placed. You can see that from the concrete powder kind of debris that was thrown up along with the red earth in the picture. The bomb did hit the cement block somewhere.

As for the glow , I really dont think the bomb had any ordnance. It would be a training bomb after all. Yes. It is the laser illuminating the target before the hit. It wont show up on naked eyes, but will definitely show up on TV cameras / digital cameras and even on film camera (you do need special IR film though for best results, especially at night).

Actually, look carefully at the 2nd picture. The laser is actually illuminating the side /base of the pyramid on the flag/top. So from that, it looks like that the practice round landed exactly where the laser was illuminating. A perfect bingo.. Good work.

But it is amazing. The Rafale, Eurofighter and all other planes entered service as pure A2A with A2G and other precision bombing coming in later blocks. But not so with the Yindoos saar! This puppy does precision strike from the day it enters service and does BVR / A2A after induction at leisure!

Maybe the Airforce needs the need for a strike platform far more urgently than A2A BVR shooter!

ramana · Post by **ramana** » 16 Dec 2010 10:08

Thanks vina.

So was the laser for guidance or ranging the LCA computer? Its important for other purposes.

If it was guiding it, is great news. If it was ranging its superb news.

Singha · Post by **Singha** » 16 Dec 2010 10:10

other reason could be the radar for BVR targeting not fully ready in those modes yet. the WVR tests of R73 worked. so HMDS must also be working. EF finally got around to dropping LGBs in 2009, around 3-5 yrs after IOC with its users. R77 and 2032 are not from same stable.

for BVR they will likely do it off Goa and fire at lakshya towed targets at high level down to sea level. since lakshya is not supersonic, I dont know how bvr shots against supersonic targets will be tested.

imo, all the 75 Mig27 in IAF service can easily be replaced (and bettered) by Tejas in A2G role. the Mig27 has a big cannon but little else to recommend itself for the modern era - too limited pylons, aeging avionics (only some were upged) , a noisy turbojet engine, ..... lacking in a2a capability of any form.

Tejas can also replace and better the 115 Bisons without a doubt.

these two add up to 200 airframes needing replacement this decade itself. Add in the older lots of Jags from the early to mid 1980s and easily 50 more will go away....

seems to me we need a FOC'ed Tejas mk1 in 150 and tejas mk2 in 150 to fill in these huge voids.

MRCA can replace and supplement the Mig29 and M2K fleet

FPGA will occupy a playing field all its own as our next strike eagle/raptorski.

ramana · Post by **ramana** » 16 Dec 2010 10:14

DNA reports:

link

Tejas: From a flying machine to fighter aircraft
Published: Thursday, Dec 16, 2010, 8:25 IST
By Hemanth CS | Place: Bangalore | Agency: DNA

A quest which started in 2001 is about to end: Tejas, India’s indigenous light combat aircraft (LCA), completed its final lap to transform into a full-fledged combat aircraft—in Bangalore on Wednesday.

After its first flight on January 4, 2001, Tejas had successfully completed 1,452 test flights, with the last one here, where it undertook air-to-ground weapon and drop tank jettison trials. Now, it is awaiting an Initial Operational Clearance (IOC)—which is likely to be given on December 27.

It all took just 20 minutes: A Tejas PV-2 aircraft took off from the Bangalore-based Aeronautical Development Agency and the National Flight Test Centre, where the LCA programme was born and brought up, hit the bulls-eye at the aeronautical test range facility in Kudapura Kaval near Chitradurga and returned to the Bangalore base.

Gp Capt (retd) RR Tyagi piloted the final test sortie and its was a huge success, said a DRDO official. Tejas can fly only for 45 minutes.

The Chitradurga facility will also serve as a test range for the unmanned air vehicles (UAVs) and the unmanned combat air vehicles (UCAVs) when it becomes fully operational in 2011.

Pratyush · Post by **Pratyush** » 16 Dec 2010 10:40

Has In Flight refueling been tested for the Tejas? As I have never seen a photograph of a Flying Tejas with the probe in fueling position.

vina · Post by **vina** » 16 Dec 2010 10:48

ramana wrote:Thanks vina.

So was the laser for guidance or ranging the LCA computer? Its important for other purposes.

If it was guiding it, is great news. If it was ranging its superb news.

Hmm. Good question. Let us look at the pictures from Tarmak .

This one is a nice cropped picture which shows the laser illuminating the side of the cement block pyramid.

http://3.bp.blogspot.com/_5sP7XwykNSM/T ... 00/asp.jpg

And then this one shows the actual hit with the concrete debris and earth thrown up at the point exactly where the laser was illuminating.

http://3.bp.blogspot.com/_5sP7XwykNSM/T ... ture+4.jpg

Now from the pictures and videos we see of laser guided weapons, the laser needs to keep illuminating the target for the seeker in the bomb to zero in on it and fly into the spot. In the second picture, you dont see the laser glow at the moment of impact (all the GWI and GWII videos had the laser tracker on until the bomb hit and you could see target open up).

I really dont think the dumb practice round would have any guidance , it would have been the small dart like thing carried in a regular bomb pod, the photos of which were posted earlier..

Kartik · Post by **Kartik** » 16 Dec 2010 11:15

Gagan wrote:The bomb missed the target by a couple of feet?

BTW are we sure this is a LGB? If it was a LGB, this was fired from say 10+ Kms off!

It was a 25 kg practice bomb. It has no guidance of its own and was not an LGB.

This is a pic of the LCA dropping a 25 kg practice bomb

Kartik · Post by **Kartik** » 16 Dec 2010 11:18

ramana wrote:Thanks vina.

So was the laser for guidance or ranging the LCA computer? Its important for other purposes.

If it was guiding it, is great news. If it was ranging its superb news.

Has to be ranging only. 25 kg practice bombs don't carry any Laser guidance kit (which would be in all likelihood as heavy as the practice bomb itself). So its basically a bullseye with a 25 kg "dumb" practice bomb that has no guidance of its own

Kartik · Post by **Kartik** » 16 Dec 2010 11:21

Pratyush wrote:Has In Flight refueling been tested for the Tejas? As I have never seen a photograph of a Flying Tejas with the probe in fueling position.

No, the IFR probe is to be included after it reaches FOC. Cobham of UK may design the retracting IFR probe.

Cobham looks at LCA fueling program

U.K.-based Cobham is in discussions with Hindustan Aeronautics Ltd. and India’s Aeronautical Development Agency about retrofitting a retractable refueling probe on the current model of the Light Combat Aircraft as well as the Mk2 version.

While Cobham is not certain how the business model will be globally tendered, the company’s experience will be a definite advantage, according to Lee Griffiths, director of Cobham India.

The Indian air force and navy are believed to be keen to get the fueling probe because of issues with flight handling, drag and movability.

“We will develop and design a retractable refueling probe,” Griffiths says. “LCA is a tightly packed aircraft ... Unfortunately, we’re later in the design period. We will roll out the retractable [version] by 2013-14.”

Singha · Post by **Singha** » 16 Dec 2010 11:40

the EF has a kind of conformal pipe housing thing...its not fully internal. you can see the diagonal pipe bulge below the right front side of canopy
http://combataircraft.net/reports/image ... ghter5.gif

perhaps same location and strategy for Tejas - for a2a patrol role definitely needed.

suryag · Post by **suryag** » 16 Dec 2010 12:30

Gp Capt (retd) RR Tyagi piloted the final test sortie and its was a huge success, said a DRDO official. Tejas can fly only for 45 minutes.

Two questions, does "final" mean no more flights needed to reach IOC ?
What combat radius can be deduced from the 45 mins thing above

Aditya_V · Post by **Aditya_V** » 16 Dec 2010 13:18

From the above article 45 minute thingie is not the quote from DRDO, ADA or HAL but the opinion by the author Hemanth CS. Dont know what's his basis but need not be necesserily correct.

Singha · Post by **Singha** » 16 Dec 2010 13:22

without mentioning the speed of flight for this 45 mins the figure is meaningless.

with IOC signing slated Dec27, they still have a week to squeeze in more weapons dropping flights like 250lb, 500lb, 1000lb, paveway/spice and so on...tickmark the boxes in the checklist.

Dileep · Post by **Dileep** » 16 Dec 2010 13:39

Don't forget that the lasers are PULSED. If the beam is off during shutter release, it doesn't show.

Pratyush · Post by **Pratyush** » 16 Dec 2010 13:41

Perhapse a newbee question.

When we speak of aircraft lazer, why do assume that it is only in visible wavelength. Could it not be in IR band making it invisible to the naked eye.

Dileep · Post by **Dileep** » 16 Dec 2010 13:43

Pratyush, it is ALWAYS IR. I have never heard of a visible laser used for target designation, except for human operated guns.

vina · Post by **vina** » 16 Dec 2010 13:59

Dileep wrote:Don't forget that the lasers are PULSED. If the beam is off during shutter release, it doesn't show.

Ah but Dileep Cheta, laser pulse rep rates are in megahertz to gigahertz , while a camera , even for a high speed movie camera types are in order of microseconds (1/1000 to 1/25000 of a sec) .. So for the duration that the camera shutter is open, the laser would have zapped some a light spot some 100 times(even if it is a nanosec pulse rep laser) and the spot would show up as a continuous event in the film/sensor.

Your problem would come only if the laser's pulse rep rate is in the same order as of the camera's shutter (say 1 sec ..very low to 1/6000 very fast, to 1/25000 ultra fast ), but for a laser , these speeds are pedestrian /nay comatose to say the least.

Dileep · Post by **Dileep** » 16 Dec 2010 14:19

No, vina. PRR of the lasers used in target designation is very very slow, only a few pulses per second.

Remember, you got to pump these things using a Xenon flash tube (or diode in later systems), which gets its energy from a charged capacitor. It takes time to build up the energy you see.

PratikDas · Post by **PratikDas** » 16 Dec 2010 14:22

^^^^
One example: http://www.l-3com.com/alst/pdfs/ALST_SellSheet_LDRF_web.pdf

Pulse rate: 8 to 20 Hz.

Pratyush · Post by **Pratyush** » 16 Dec 2010 14:40

Dileep wrote:Pratyush, it is ALWAYS IR. I have never heard of a visible laser used for target designation, except for human operated guns.

Oh.......

Thanks

Philip · Post by **Philip** » 16 Dec 2010 14:45

Surely,when the need for in-flight refuelling for the IAF's aircraft was mooted,quite some time ago,why did this essential requirement for a light fighter like the LCA never excited the minds of our boffins? Where was everbody,IAF included,sleeping on the job? There is however another problem,the small number of air-tankers in service and planned.They cannot be everywhere and probably will receive prioroity refuelling our Flankers and MMRCAs first.

This underscores the remark made by an AM familar with the project that the LCA in current form can mainly serve for point defence.To now install a refuelling system in such a tightly packed airframe for both MK1 and MK2,will be a real headache and require further redesigning and testing.If its endurance is only 45 mts.,what reasonable payload can it carry for G.Attack/close support ops and at what range/combat radius without refuelling? I daresay that the MIG-27 has at least an equal or even better range and is definitely better armoured.Armour is essential for the GA role as both A-10s and SU-25s are heavily aroured to withstand smallarms/anti-aircraft fire and even missile damage. A twin-engined upgraded Jaguar might prove to be a better bet than the LCA for such a role.

Though the ground attack capability of the LCA is very welcome,I personally feel that it is in air-combat where it will excel best,destroying Paki JF-17s,etc.,given its small size and small radar return due to extensive use of composites and ability to carry both advanced BVR and WVR missiles used by larger aircraft like the SU-30MKIs.

vina · Post by **vina** » 16 Dec 2010 14:53

Dileep wrote:No, vina. PRR of the lasers used in target designation is very very slow, only a few pulses per second.

Oh I see. It's a pity that the DRDO did not put out a video of that, but just still images. In a video such low pulse rate would have shown up as clear flicker in intensity (at 8 to 20 hz) (at 50 HZ you have full persistence of vision, just like in television and will show up at constant intensity) and it would have decided in one way or another whether it was laser guided.. But given the absence of any large sized projectile visible in the photo (a LGB inert bomb is still sizeably big to show up on the photo), I would still put the money on a 25lb or a 3KG training round as in the BR Gallery of IAF A2G weapons.

ashokpachori · Post by **ashokpachori** » 16 Dec 2010 15:24

Although the observers have to be able to see the target to designate it, the infrared laser pulses are invisible to the naked eye. The pulses are only visible if observed through a platinum-silicide (PtSi) CCD camera (similar to a home video camera) or night-vision devices operating in the near-IR spectrum (0.7 to 3.0).

uddu · Post by **uddu** » 16 Dec 2010 15:32

lol. so much for the bright light. It may be divine light or a wonderful bulb of 200W being lighted so that the pilot with poor eyesight can see the target properly or it can be someone pointing a torch onto the target to check it is intact or not.
Guys the bomb was a training round.
"Shri PS Subramanyam, Programme Director (CA) & Director, ADA said that on December 15, 2010, Tejas PV-2 aircraft piloted by Gp Capt (Retd) RR Tyagi dropped practice bombs on the target."
Now do we have laser guided practice bombs? or do we have Photoshop++.

Kanson · Post by **Kanson** » 16 Dec 2010 15:34

I agree with Shiv's contention.

If the target is laser illuminated, it will be right on center of the Pyramid like structure and not on the surface near the pyramid. The flame of ball is somewhere near & close to the pyramid but not right on the pyramid. The flame of ball size increases, in one frame it is small and in another frame it is bigger and is asymmetric, that only explains the explosion.

It looks more like these shorts are taken from high speed camera, where the bomb fell near the pyramid structure resulted in explosion near the pyramid but not on the pyramid and debris thrown after the explosion near the pyramid leaving the pyramid almost intact.

During the Kargil operation, it was reported, Mirage-2000 team developed accurate technique of hitting the target as good as PGMs using plain bombs .

uddu · Post by **uddu** » 16 Dec 2010 15:39

It's not laser for sure. It is either the blast or Photoshopped picture for the Indian media.

Pratyush · Post by **Pratyush** » 16 Dec 2010 15:42

Guys,

Even with dumb bombs a high degree of accuracy can be attained. IIRC, during Kargil it was reported that using a stop watch and GPS the Mig 21s achieved a high degree of accuracy when engaging ground targets.

So it is possible that the Tejas could engage targets in a similar fashon.

Lalmohan · Post by **Lalmohan** » 16 Dec 2010 16:41

the LCA should have a nav/attack computer that can enable it to drop bombs right on target under 'good' conditions, needs a good pilot and steady hands - normally the release is computer controlled

merlin · Post by **merlin** » 16 Dec 2010 19:05

Philip wrote:Surely,when the need for in-flight refuelling for the IAF's aircraft was mooted,quite some time ago,why did this essential requirement for a light fighter like the LCA never excited the minds of our boffins? Where was everbody,IAF included,sleeping on the job? There is however another problem,the small number of air-tankers in service and planned.They cannot be everywhere and probably will receive prioroity refuelling our Flankers and MMRCAs first.

This underscores the remark made by an AM familar with the project that the LCA in current form can mainly serve for point defence.To now install a refuelling system in such a tightly packed airframe for both MK1 and MK2,will be a real headache and require further redesigning and testing.If its endurance is only 45 mts.,what reasonable payload can it carry for G.Attack/close support ops and at what range/combat radius without refuelling? I daresay that the MIG-27 has at least an equal or even better range and is definitely better armoured.Armour is essential for the GA role as both A-10s and SU-25s are heavily aroured to withstand smallarms/anti-aircraft fire and even missile damage. A twin-engined upgraded Jaguar might prove to be a better bet than the LCA for such a role.

Though the ground attack capability of the LCA is very welcome,I personally feel that it is in air-combat where it will excel best,destroying Paki JF-17s,etc.,given its small size and small radar return due to extensive use of composites and ability to carry both advanced BVR and WVR missiles used by larger aircraft like the SU-30MKIs.

That 45 minutes, if true, must be for full internal fuel only. With drop tanks it should be more.

shiv · Post by **shiv** » 16 Dec 2010 20:12

merlin wrote:
That 45 minutes, if true, must be for full internal fuel only. With drop tanks it should be more.

May not even be full internal fuel. The aircraft is being used for testing and will be packed with telemetry equipment. Recall that oddball view of R-73 being launched from a camera placed godknowswhere on the LCA. And note that PV-2 is being used - not one of the LSPs

From Tarmak's blog
http://tarmak007.blogspot.com/2010/12/b ... tores.html

Shri PS Subramanyam, Programme Director (CA) & Director, ADA said that on December 15, 2010, Tejas PV-2 aircraft piloted by Gp Capt (Retd) RR Tyagi dropped practice bombs on the target. Thus NFTC, ADA became the first to use the facility for weapon testing on Tejas. For this purpose, air-to-ground target and Range Safety Officer (RSO) bunkers were constructed at the range site. NFTC mobile telemetry with Test Director and critical system monitoring personnel were also positioned at the test range. The mobile telemetry was linked to the base station Bangalore, through BSNL fiber optic link to monitor the test aircraft data and video in real-time.

Gaur · Post by **Gaur** » 16 Dec 2010 20:43

Could it be just a flare? The pilot surely would not be able to spot a small pyramid. The real life targets are "much" larger. Perhaps the flare was just to aid the pilot in easier spotting of the target?

IMO, there is certainly no chance that a 25 kg bomb would have a guidance system.