LCA News and Discussions

nikhilarora · Post by **nikhilarora** » 12 Jul 2011 14:21

rajanb wrote:LCA very busy today. 12:30PM
The deep throated roar of its engine.

Actually, the trials have been going for sometime now, almost daily. I have seen or heard the Tejas fly on nearly every day of the last week except Sunday I guess. Last saturday, there was this clear sky and the tejas just roared across the horizon. It took a sharp turn and also did a roll. From the distance it looked totally like an Arrow head and as it turned, it was shining bright in ths sun, looked UBER-COOL.

chackojoseph · Post by **chackojoseph** » 12 Jul 2011 15:29

Images: LCA Tejas MK 1

Cross post. Some Images may be new.

Aditya_V · Post by **Aditya_V** » 12 Jul 2011 15:40

Manish_Sharma wrote:
karan_mc wrote:LSP-6 will not take off before LSP-7 (Due on August) and LSP-8 (Due on oct) and , SP-1 and SP-2 by Jan -March 2012 period
Why is that?

Read previous pages- LSP-6 is an experimental aircraft.

neerajb · Post by **neerajb** » 12 Jul 2011 16:26

This is the type of image I wish to see. Full squadron of Tejas, lined up on the tarmac ready to whip some Paki/Chini ass.

The middle one has no air scoop and the tail number is not visible too. It's my guess that it is PV1, looks like KH-2011 to me on the tail.

Cheers....

rohitvats · Post by **rohitvats** » 12 Jul 2011 18:23

^^^Wah!Wah!...beautiful pic!

Kartik · Post by **Kartik** » 12 Jul 2011 21:13

Shrinivasan wrote:
neerajb wrote:I remember a news post on BR which said that LCA doesn't carry a cannon as yet. I was watching LSP4 first flight video on http://www.tejas.gov.in and here is what I found, a cannon under starboard side air intake. Has it been test fired yet from Tejas?
IMHO it was fired during trials in Goa or Chitradurga after the missile test but before the Bomb drop tests, couple of weeks before IOC.

source of that info ?

chackojoseph · Post by **chackojoseph** » 12 Jul 2011 21:30

IMO canon firing has not been attempted.

neerajb · Post by **neerajb** » 12 Jul 2011 23:12

chackojoseph wrote:IMO canon firing has not been attempted.

Chacko can you dig deeper why it has not been tried yet even after IOC?

Cheers....

chackojoseph · Post by **chackojoseph** » 13 Jul 2011 09:14

neerajb wrote:
chackojoseph wrote:IMO canon firing has not been attempted.
Chacko can you dig deeper why it has not been tried yet even after IOC?

Cheers....

I had kept this query last year. Followed it up. Dead end.

Shrinivasan · Post by **Shrinivasan** » 13 Jul 2011 11:33

chackojoseph wrote:IMO canon firing has not been attempted.

CJ, can u check around the chitradurga tests time frame, they fired the cannons in goa I think. Let me check my archives too.

Gilded my 700th post.

Prasad · Post by **Prasad** » 13 Jul 2011 11:39

IIRC there was a post on here which said they left the cannon tests for post-IOC since its the easier part. Couldn't dig that up right now.

suryag · Post by **suryag** » 13 Jul 2011 11:53

^^^ Shrinivasan ji IIRC(and i am 99% sure) cannon firing hasnt been attempted. Even in the Chitradurga trials it was CMDS/dumb bombs and r-73 were tested among-st others.

Shrinivasan · Post by **Shrinivasan** » 13 Jul 2011 11:59

suryag wrote:^^^ Shrinivasan ji IIRC(and i am 99% sure) cannon firing hasnt been attempted. Even in the Chitradurga trials it was CMDS/dumb bombs and r-73 were tested among-st others.

I'll dig my archives and post details tomorrow, test was either near Nagpur or in goa, around chitradurga test timeframe, not there.

Shrinivasan · Post by **Shrinivasan** » 14 Jul 2011 11:08

Shrinivasan wrote:
suryag wrote:^^^ Shrinivasan ji IIRC(and i am 99% sure) cannon firing hasnt been attempted. Even in the Chitradurga trials it was CMDS/dumb bombs and r-73 were tested among-st others.
I'll dig my archives and post details tomorrow, test was either near Nagpur or in goa, around chitradurga test timeframe, not there.

Gentlemen, I stand corrected, LCA Tejas's Gun has not been tested in flight. It has only been tested on ground (both separately and after mating with the aircraft). As Gurus rightly said, this has been planned for the post IOC phase.

Indranil · Post by **Indranil** » 14 Jul 2011 11:15

you must have got confused with the dhruv-WSI cannon trials in Nasik

suryag · Post by **suryag** » 14 Jul 2011 11:17

It has only been tested on ground (both separately and after mating with the aircraft). As Gurus rightly said, this has been planned for the post IOC phase.

Sources shrinivasan ji for the above?

Shrinivasan · Post by **Shrinivasan** » 14 Jul 2011 12:13

indranilroy wrote:you must have got confused with the dhruv-WSI cannon trials in Nasik

probably, more than the Druv-WSI, the what misled me was the next steps laid out like firing R-73 and firing gun, dropping dumb bombs and guided bombs, dropping filled / empty drop tanks.
Every other item except firing guns has been tested for the LCA.

Shrinivasan · Post by **Shrinivasan** » 14 Jul 2011 12:25

suryag wrote:
It has only been tested on ground (both separately and after mating with the aircraft). As Gurus rightly said, this has been planned for the post IOC phase.
Sources shrinivasan ji for the above?

Chaiwaala source for the tests.... Gashas for yell cee yaah was customized in OFT (Ordnance Factory Trichy) and they were first tested by mounting on a pedestal, slaved to the yoke control in LCA with control cables running for a good distance. Once the GSH-23 Gasha guns were mounted on the LCA, they were tested from the ground (in BLR I presume).

tsarkar · Post by **tsarkar** » 14 Jul 2011 15:40

Shrinivasan wrote:Once the GSH-23 Gasha guns were mounted on the LCA, they were tested from the ground (in BLR I presume).

Unlikely. The weapons control computer disables all weapons & chaff-flares whenever undercarriage is down. This is a safety feature to avoid accidental weapons discharge when aircraft is on the ground.

That is why when our MiG-21 intercepted Pakistani Atlantique, they ordered it to lower its undercarriage. That would immediately disable any weapons/flares deployment.

Gasha is the old MiG-21 gun manufactured since late 60's. An indigenous twin pack for fuselage mounting was hastily developed in 1971 when the R-13 missiles (both Russian and BDL manufactured) were found unreliable. The fuselage gun pack shot down Mervyn Middlecoat's Starfighter.

Rahul M · Post by **Rahul M** » 14 Jul 2011 15:45

it won't be hard to disable the undercarriage safety mechanism for a test.

SaiK · Post by **SaiK** » 14 Jul 2011 15:52

Any way possible to have the cannon in active mode with landing gear engaged? Wouldn't this be useful during a war?

tsarkar · Post by **tsarkar** » 14 Jul 2011 16:03

^^ In that case, the gun exhaust gases would boil the front wheel hydraulic oil and melt the rubber. While flying, the airflow around the fuselage rapidly disperses the exhaust gases.

On the ground, the recoil would shear the undercarriage and move the plane backwards. While flying, the aircraft engine thrust compensates for the gun recoil.

These are high power high rpm guns, not WW2 pea-shooters.

On ships, major component of CIWS mounting (using similar guns) is shock mounting to absorb recoil.

That is why AK-630 weighs ~ 9 tonnes even though the GSh-6-30 gun weighs ~ 150 kg.

The same GSh-6-30 gun is mounted on MiG-27 minus structural components of AK-630. In the air, the massive engine thrust compensates for the recoil. Even then, when using these guns, the pilot still gets a kick.

SaiK · Post by **SaiK** » 14 Jul 2011 16:21

wonderful response tsarkar, assuming that the structure is designed can take the recoil and shear, how much of a safe distance (inches?) redesign is required to keep the wheel rubbers away from the exhaust gas?

Lalmohan · Post by **Lalmohan** » 14 Jul 2011 16:36

i thought aircraft guns were tested on ground for calibration purposes?

Rahul M · Post by **Rahul M** » 14 Jul 2011 16:40

good point about the recoil, missed it somehow.

Indranil · Post by **Indranil** » 14 Jul 2011 16:46

tsarkar ji is right!

It is part of the reason why lowering your undercarriage in aerial dogfights is the universal sign of the pilot giving up.

SaiK · Post by **SaiK** » 14 Jul 2011 17:24

^sure, but it can't be on operational protocol.. how do you know if the enemy is not deceiving you to get a lock?

shiv · Post by **shiv** » 14 Jul 2011 17:43

Rahul M wrote:it won't be hard to disable the undercarriage safety mechanism for a test.

The thing to do is to mount the aircraft on a rig, raise the undercarriage and blaze away.

Indranil · Post by **Indranil** » 14 Jul 2011 17:57

SaiK wrote:^sure, but it can't be on operational protocol.. how do you know if the enemy is not deceiving you to get a lock?

because he is in front of you and most probably in your cross hairs (and recognizes it).

tsarkar · Post by **tsarkar** » 14 Jul 2011 18:15

shiv wrote:The thing to do is to mount the aircraft on a rig, raise the undercarriage and blaze away.

With the rig and airframe grinding against each other and any rubber or neoprene to prevent the grind melted in the heat.

Without 300 kmph airflow (assuming that's the minimum airspeed) to cool the airframe and disperse the gases, the hydraulics are still going to boil.

Much simpler to test only the weapon control computer, associated electricals, databus and gun firing. Who needs rest of the airframe for ground testing?

Just like missiles/bombs are tested on rocket sledges in the ground and then in the air with the aircraft, same goes for guns.

shiv · Post by **shiv** » 14 Jul 2011 18:20

tsarkar wrote: Without 300 kmph airflow (assuming that's the minimum airspeed) to cool the airframe and disperse the gases, the hydraulics are still going to boil.

2-4 round bursts are hardly going to do all that damage - or those guns cannot be tested at all. A bit of suitable cladding on exposed airframe and nothing will happen. After all aircraft are commonly tested static on the ground with the engine going full blast - even afterburner so airframe stress from firing a few short rounds need not be an issue.

tsarkar · Post by **tsarkar** » 14 Jul 2011 18:28

3600 rpm with 220 rounds carried. One second expends 60 rounds and all over in 4 seconds. They are tested in ground rigs - minus rest of the airframe

Added later - I dont know and I've never heard of single round firing by aircraft or CIWS guns, however these guns are not accurate (because of the ratio of the length of barrel to round caliber is relatively low), their role is to concentrate fire in the minimum range of a WVRAAM's envelope (typically 2 km). They are not as accurate as 30 mm cannon of an ICV or 35 mm AA gun, so firing 1-2 rounds will not yield results given the (relatively) high dispersion (vis-a-vis 35 mm AA cannon or 30 mm ICV cannon)

Rahul M · Post by **Rahul M** » 14 Jul 2011 18:31

shiv wrote:
Rahul M wrote:it won't be hard to disable the undercarriage safety mechanism for a test.
The thing to do is to mount the aircraft on a rig, raise the undercarriage and blaze away.

they can use the decomm-ed airframes as ground test articles. that way stress on airframe is not a big problem.

shiv · Post by **shiv** » 14 Jul 2011 18:35

Unless you do a static test you won't know if your gun mounting and the protection at the business end is safe for a subsequent flying test. Check the mounting at 15 sec. Also the made in Bangalore, Kerala jute rope.

http://www.youtube.com/watch?v=NBXrogB8L08

tsarkar · Post by **tsarkar** » 14 Jul 2011 18:58

^^ I stand corrected. I have always known pilots testing their guns at Jamnagar and Kalaikunda against hunters towing targets or air to ground ranges for reasons cited.

I was told this http://www.flickr.com/photos/torqueavia ... 5696912454
could be done only in air. Not sure whether its because the A-10 is more ruggedly built or all aircraft, including Tejas and MiGs can do it on the ground.

Secondly, I dont see any spent shells ejecting unlike GSh series guns. If fired on the ground, the shells will ricochet against tarmac and the airframe

Added later - http://en.wikipedia.org/wiki/GAU-8_Avenger

The GAU-8/A utilizes recoil adapters. They are the interface between the gun housing and the gun mount. By absorbing (in compression) the recoil forces, they spread the time of the recoil impulse and counter recoil energy transmitted to the supporting structure when the gun is fired.

Not sure whether this is standard fit to all fighters.

The feed system is double-ended, allowing the spent casings to be recycled back into the ammunition drum,[11] instead of ejected from the aircraft, which would require considerable force to eliminate potential airframe damage.

Looks like a nyet for a GSh-23 that ejects shells.

The GAU-8 itself weighs 620 pounds (280 kg), but the complete weapon, with feed system and drum, weighs 4,029 pounds (1,828 kg) with a maximum ammunition load...The magazine can hold 1,174 rounds, although 1,150 is the typical load-out.

OT - Either Bangalore, Karnataka or Trivandrum, Kerala. What is Bangalore, Kerala? Isnt it an oxymoron? Unless you missed a qualifier "or" "and" between Bangalore and Kerala.

Mihir · Post by **Mihir** » 14 Jul 2011 19:47

shiv wrote:The thing to do is to mount the aircraft on a rig, raise the undercarriage and blaze away.

Precisely. The video below shows an Su-34's air-to-surface missiles and gun being tested in a similar way. Note that the undercarriage has been lowered.

http://youtu.be/OSgPGZcmgT4?t=2m40s

SaiK · Post by **SaiK** » 14 Jul 2011 19:47

indranilroy wrote:
SaiK wrote:^sure, but it can't be on operational protocol.. how do you know if the enemy is not deceiving you to get a lock?
because he is in front of you and most probably in your cross hairs (and recognizes it).

Now we are adding conditionality to the argument. Why do you think he must be in front of me? okay, assume he is in front, and in my cross hair, still, by the acceptance of him lowering the carriage, my actions are always secondary considering his first move.

Are you saying, I am not in his cross hair, and that can be monitored on my LCA? that would be awesome dude!.. then we have it.

Lalmohan · Post by **Lalmohan** » 14 Jul 2011 19:53

in the korean war, a usaf shooting star got behind a n.korean/chinese biplane artillery spotter to shoot it down. it had to drop flaps, slats and undercarriage to get slow enough to get a lead on to the target. after blasting the biplane out of the sky, the shooting star stalled thanks to the recoil of the 6 x 0.50 cal brownings in the nose, and i believe it too crashed

shiv · Post by **shiv** » 14 Jul 2011 20:07

I believe this "lowering of undercarriage" as a signal that a plane should not be shot down is only in the context of an unarmed aircraft overflying a prohibited area being intercepted. The pilot lowers the the undercarriage indicating that he is willing to land as demanded. He will still get shot up if he tries to get away after that.

In the context of an attack fighter over enemy territory being intercepted it makes no sense whatsoever unless he is defecting like Viktor Belenko. No defending interceptor is going to let an attacker "get away" simply because he gives up and lowers his undercarriage. He will get away and attack another day. Besides - where would he land? On the target he was attacking 2 minutes before he got into someone's crosshairs?

shiv · Post by **shiv** » 14 Jul 2011 20:09

tsarkar wrote:
OT - Either Bangalore, Karnataka or Trivandrum, Kerala. What is Bangalore, Kerala? Isnt it an oxymoron? Unless you missed a qualifier "or" "and" between Bangalore and Kerala.

Bangalore, Kerala