LCA News and Discussions

Lalmohan · Post by **Lalmohan** » 09 Jul 2010 14:46

who is the wateriest of all the apsaras?

Manish_Sharma · Post by **Manish_Sharma** » 09 Jul 2010 15:00

I repeat again that Tejomayee would be perfect watching the curves and long legs Naval LCA. Fierce sister of Bad Boy Tejas. Also females of all species are more fierce protectors, so she will protect the Carriers and Shores with utmost intensity.

Still if everyone wants a boy then Tarun would do nicely.

Lalmohan · Post by **Lalmohan** » 09 Jul 2010 16:12

Didn't LTrahmos programme come with a side cooperation agreement called Jamuna-Don for active jamming technology to rival Spectra? It was being called Jamunadon but got confused with a palaentology programme or Jammedon to be more accurate to its intent. I heard that a lot of money and natasha's passed hands and somebody's uncle in HAL and/or DRDO got caught in the honey trap and the programme has gone on ice ever since. There were also rumours of a Volga-Ganga project codenamed Vulva, but I don't know too much about that one

gogna · Post by **gogna** » 09 Jul 2010 16:35

could naval lca be armed with brahmos? if not which anti ship missile would it carry?
many thanx

krishnan · Post by **krishnan** » 09 Jul 2010 16:41

gogna wrote:could naval lca be armed with brahmos? if not which anti ship missile would it carry?
many thanx

LTrahmos

Kanson · Post by **Kanson** » 09 Jul 2010 17:29

Hi All

Which site hosts all the Naval LCA opening ceremony pics ? TIA.

Kanson · Post by **Kanson** » 09 Jul 2010 17:32

gogna wrote:could naval lca be armed with brahmos? if not which anti ship missile would it carry?
many thanx

Unless Brahmos can shed more weight....needs to be seen. Of course there are other missiles from Russians, Americans & others.

Kanson · Post by **Kanson** » 09 Jul 2010 17:39

vina wrote:Me thinks this is good ol' Kangress party's dirty tricks dept at work again. See, they would hate a name given by Vajpayee and since the Naval version is distinct and different and the Navy would like a name of it's own, why not put two and two together and when the time comes, bestow it with a "Kangress" name at the time of the first flight . So, would expect MMS/ Madam to pick out a name for the Navy fighter when it makes a first flight.

Normally it is the Navy or ones assoicated with defence and LCA decides the name, if they want it to be different. ABV/Tejas seems to be an exception. So far Ol' kangress tentacles touched only civilian infrastructre only. They wont touch the war machine as associating the family name to war machine gives different perception which very much negates their peaceful & liberal outlook. You can bet on it.

Lalmohan · Post by **Lalmohan** » 09 Jul 2010 17:40

Kanson - shed more weight? thats it?

Kanson · Post by **Kanson** » 09 Jul 2010 17:47

Cybaru wrote:
Katare wrote:Damn you Cybaru now they'll have to cancel LTrahmos and start a new project with a secret name
Dammit.. Okay Okay, My bad. I plead temporary insanity. I am not sure what dark force made me reveal such sensitive information on this website. It must be the work of a SETH master.

I guess that wont get you a pardon. Be prepared to do penance for this by voluntarily opting for a DH job in the Indian embassy in Pak, right?

Kanson · Post by **Kanson** » 09 Jul 2010 17:50

Lalmohan wrote:Kanson - shed more weight? thats it?

Oopps..LCA has to put more weight, in addition... Laws of Conv. of mass only...

Cybaru · Post by **Cybaru** » 09 Jul 2010 18:32

putnanja wrote:
Dileep wrote:Now I am konphoosed onlee! I thought good old cy was joking to begin with.
He was, and others were playing along with him. Good performance by chacko though

Yeah, That was indeed good by Chacko..

Kanson, hahah, not a chance...

Lalmohan wrote: Didn't LTrahmos programme come with a side cooperation agreement called Jamuna-Don for active jamming technology to rival Spectra? It was being called Jamunadon but got confused with a palaentology programme or Jammedon to be more accurate to its intent. I heard that a lot of money and natasha's passed hands and somebody's uncle in HAL and/or DRDO got caught in the honey trap and the programme has gone on ice ever since. There were also rumours of a Volga-Ganga project codenamed Vulva, but I don't know too much about that one

LOL!!

chackojoseph · Post by **chackojoseph** » 09 Jul 2010 18:53

I was speaking generallllly onleeeeeee.

Juggi G · Post by **Juggi G** » 10 Jul 2010 02:53

LCA (Navy) Will Add Punch To Blue Water Vision, Adm. Nirmal Verma Says
Aviation Week

Navy Chief Interview

Bihanga · Post by **Bihanga** » 10 Jul 2010 18:02

gogna wrote:could naval lca be armed with brahmos? if not which anti ship missile would it carry?
many thanx

Well, so far there is next to no inputs about LCA being armed with Brahmos unless we conduct System and Development phase of such airborne Brahmos. But we can certainly use existing missiles in our armoury like Sea Eagle, Exocet as well as Russian KH series as a gap filler.

Lalmohan · Post by **Lalmohan** » 10 Jul 2010 21:17

guys, please use some common sense and look at the relative dimensions of the LCA and Brahmos before posting ad nauseum about why they aren't being mated

Kanson · Post by **Kanson** » 10 Jul 2010 21:58

http://ajaishukla.blogspot.com/2010/07/ ... -ardc.html

The Tejas has currently tested an Alpha of just 22-24 degrees, and will go up gradually to 28 degrees. But flying a higher Alpha risks stalling the fighter; its engine could go off (or flame out, as pilots call it) leaving the Tejas --- without propulsion power, or electrical and hydraulic power for its fly-by-wire controls --- to fall out of the sky like a stone.

To guard against that, the ARDC is fitting a test Tejas with a fast-response power pack that US company, Honeywell, manufactures for such flight-testing. Within milliseconds of the Tejas main engine going off, the hydrogen-operated power pack starts up, providing power to the fighter’s hydraulic and electrical systems, and re-lighting the main engine.

“In flying a single-engine aircraft, there is no bigger emergency than a flame-out”, says a former Tejas test pilot. “But no fighter engine should flame out at just 28 degrees Alpha. However, the Tejas air intakes have not been well designed and, as the Alpha increases, the intakes constrict the airflow, and the engine dies for want of air.”

In contrast to the Tejas’ maximum Alpha of 28 degrees, India’s Sukhoi-30MKI can comfortably handle an Alpha of over 50 degrees. The US Navy F/A-18 Super Hornet can manage an Alpha of 58 degrees.

The Tejas flight test programme, India’s first such testing process, has been controversial, with critics charging that the slow speed of testing has delayed the Tejas’ induction into service. On the positive side, the Tejas testing has given birth to the National Flight Test Centre (NFTC), a test facility that is of global standard. The Aeronautics Development Agency (ADA), which oversees the Tejas’ development, has now engaged European aerospace giant, EADS, to advise on how to speed up testing.

“We have to proceed cautiously”, the Tejas programme director, PS Subramaniam told Business Standard while witnessing a test last year. “We have managed to come so far without a single mishap. An accident would seriously damage the credibility of the Tejas programme.”

Whenever someone writing an opinion piece who doesnt have a grasp on the subject it is always desirable to get an expert opinion from more than one person before publishing them, otherwise it is most likely to end up as trash and will cause unnecessary heartburns.

It is well known that throu' wind tunnel studies of Tejas it was established that when it goes over an alpha of 25 deg, the stability in other axis started diminishing. This is expected as you extend the slats and flaps to max position to attain the max possible AoA, as the control surface is getting positioned to max setting..a/c start loosing stability unless proper control authority is established to mitigate that loss. It is a common problem in every aircraft. For ex., C-17 too experiences the same problem when it approaches at high AoA during assault landing in a short runway. Nothing unusual about it. It has be analysed by slowly expanding the flight regime and a proper control has to be coded into control laws. That is what these tests are meant to be. That is becoz of the same reason, AoA testing was restricted so far to 24 deg. As such high AoA testing are risky, it was reported that ADA will do the AoA testing in consultation with EADS. Any improper AoA test leads to aircraft crash. So it makes perfect sense when Mr. Subramaniam says, "We have to proceed cautiously". New Air data computer (ADC) recently added to the LSP helps to test the aircraft for such AoA.

So how is that when the aircraft was not tested for more than 24 deg AoA, Mr. Ajai Shukla quoted an ex- test pilot mentioning engine flame out at 28 deg AoA ? That's where comes the poor job of Ajai Shukla who was unable to comprehend the remarks of the ex- test pilot.

As i mentioned before, it was calculated throu' studies that, at greater than 25 deg AoA, if the aircraft was tested without taking proper precautionary measures, the aircraft *might* slip out of control. When it slips out of control and started spinning, engine flame out will occur. When such engine flame out occurs, a 'fast response system' has to be installed to restart the engine from any such flame out. That is why Shukla reported, "To guard against that, the ARDC is fitting a test Tejas with a fast-response power pack that US company, Honeywell, manufactures for such flight-testing."

An inquisitive journalist should have asked, "if ARDC is ordering the fast-response power pack only now, how was the testing so far proceeded". That would have highlighted the fault in his thinking that a flame out had indeed occurred when Tejas was put to 28 deg AoA. 28 deg AoA was the ASR requirement, as per Shukla. So it was expected that the aircraft will be tested for upto 28 deg AoA for getting IOC. The selected consulting agency will help in getting the AoA clearance with less risk. That's the whole story behind it. Unfortunately, Mr. Shukla twisted it.

Now comes the another interesting question which Mr. Shukla raised in his article. Can Tejas do a 50 deg AoA ? Yes, only after proper testing and analysis carried out in assessing the a/c characteristics at that AoA.

In simple, so far, aircraft testing validated the theoretical projection of aircraft characteristics upto an alpha of 24 deg only. Further testing is needed to evaluate the remaining theoretical projection. It the IAF says, we dont want more than 28 deg AoA, testing will be stopped at that.

karthik · Post by **karthik** » 11 Jul 2010 00:13

DELETED.

Surya · Post by **Surya** » 11 Jul 2010 00:19

sunilUpa · Post by **sunilUpa** » 11 Jul 2010 00:20

Double Sigh..

Telang · Post by **Telang** » 11 Jul 2010 00:36

We may have not understood or known LCA after millions of posts here; there may still be something unknown to us about the bird, but as for Colonel Shook-la, every one knows everything about him. He is a great fiction writer. and just the opposite of "Cheer leader". We may even call him "spoil-sport".

putnanja · Post by **putnanja** » 11 Jul 2010 00:38

-deleted --

Rahul M · Post by **Rahul M** » 11 Jul 2010 00:58

karthik, in my judgement your post was ignorant of facts and didn't add anything to this thread, for the last time don't pretend as if criticism is frowned upon on BR, it is not. but ignorance certainly is, if you can't make the minimum level(again judged by my fellow mods and myself as per BR rules) I would keep deleting your posts and/or warn you when things get out of hand.
moreover, if you use profanity against other members even in reports you will be warned for that too.

any further queries on this issue should be made in feedback thread and not here.

Philip · Post by **Philip** » 13 Jul 2010 13:19

There is a recent pic in AWST of the T-50/PAK-FA taking off at an AoA of what appears to be 35deg+,drawing praise from the report's author.It was a special performance for premier Putin.Putin and Medvedev seem to be taking special interest in the modernisation of their armed forces,Medvedev was in the Far East watching a naval exercise too.I only wish our top leadership took at least 10% interest of that of the Russian duo.It would make a huge difference.One gets very depressed when one reads of another few years of Kaveri development and more money being thrown at it.Britain has just unveiled its new UCAV,Taranis,which is going to play a major role in its air strategy in the future.When will our own UCAV based upon LCA tech developed mature?

Rahul M · Post by **Rahul M** » 13 Jul 2010 13:46

in a take-off the AoA cannot be 35deg+. it's a steep angle take-off (which shows high TWR) but AoA means the angle between the axis of the aircraft and the direction of forward motion, in take-off those two are coincident to a high degree.

Philip · Post by **Philip** » 13 Jul 2010 13:48

Stand corrected.By the way,what is the AoA of the Su-30 with TVC?

Rahul M · Post by **Rahul M** » 13 Jul 2010 13:51

around 35+ within FBW limits IIRC, higher without. could be wrong though.

Dileep · Post by **Dileep** » 13 Jul 2010 14:51

AoA on all the talk about AoA.

Well, the test pilot quoted by Ajai Shukla said

“In flying a single-engine aircraft, there is no bigger emergency than a flame-out”, says a former Tejas test pilot. “But no fighter engine should flame out at just 28 degrees Alpha. However, the Tejas air intakes have not been well designed and, as the Alpha increases, the intakes constrict the airflow, and the engine dies for want of air.”

It doesn't mean that a flameout has happened. I guess the pilot tried to explain the "fear of flameout" to Ajai, and he might have understood it differently.

What confuses me is which happens first? Airframe stall, or engine flameout? IMLMO, a well designed plane should have the airframe stall before engine flames out. I know for a fact that all these things are paranoiacally simulated to death at the initial stages of design, and till now, that effort paid ample dividend. Maybe the simulations did not guarantee non-flameout at, say 33.6 degrees boundary limit. Hence the scare.

Telang · Post by **Telang** » 13 Jul 2010 15:54

Paranoia attached to LCA may not be OT I hope. I remember to have seen on TV channels (such as discovery etc.) a lot of failures / crashes etc caught on camera while developing an aircraft. The way our colonel writes on such failures or possible failures which is so horrendous that were he to be on the scene of such crashes and were he to write on them, all the American big names in aerospace would have packed up their business by now. What a cheer leader for Pukistan here amidst us Indians!

There seems to be a general belief that all the technology is stored in the Reserve Bank of India and that the Indian scientist is guilty of laziness in failing to draw and work on it!! Colonel sahib, if the test pilot told you, he may have also told the people who are to take care of it on the aircraft. And those who have been told, may be working on it. I for one have a lot of confidence on the Indian scientist. If it is misplaced in somebody's view, so be it.

tsarkar · Post by **tsarkar** » 13 Jul 2010 16:17

Ummm, all Ajai says is "could", just like Vina says "might", with both of them hinting at some degree of uncertainity that exists in the last phases of testing before IOC.

Ajai is quoting verbatim the test pilot's "fear of flameout", I dont find him misunderstanding/speculating anywhere in the article. Go easy on the chap

More important, who can shed light on what goes into inlet design? The impression one gets - reading the quote & referring to Ajai's earlier article wherein additional spring loaded inlets were proposed to be added - is that the cross section is small and constricting airflow.

My extremely limited understanding based on ships is that gas turbines need copious amounts of air http://www.rolls-royce.com/Images/MT30% ... 2-8654.pdf (Refer page 5 & 9 dimensions)

However at the same time, there exists the very successful Saab Draken with inlet cross section much smaller than Tejas http://www.aviastar.org/pictures/sweden/saab_draken.gif

So why does the test pilot say "Tejas air intakes have not been well designed"?

Is it a quick fix job, like the Chinese JF-17 and J-10B inlet redesign jobs? Or do we need to hack lockheed databases? Or more likely pay someone exorbitantly for consultancy/ToT?

Lalmohan · Post by **Lalmohan** » 13 Jul 2010 18:08

^^^ air intake flow design is very complicated, particularly in fighters where the engine is located quite a way back from the inlet. Every change in angle is a pressure drop which lowers the available air flow to the first stage compressors. at high alpha there may be a non-linear drop off in pressure and/or flow separation problems, leading to a more rapid onset of flameout than is desirable

lots of older aircraft had small inlets assuming they would have plenty of straight flow, and i doubt if they were designed to fly at high alpha. so the problem could be on the margins of the envelope rather than a base case air flow one for Tejas

in terms of 'copius' amounts of air, jets have been known to suck up spanners and screwdrivers from the tarmac, which is why there is so much attention paid to Foreign Object Damage (FOD) at airfields, all personnel are required to ensure that no items fall or are left on the ground in case of inadvertent ingestion

Rahul M · Post by **Rahul M** » 13 Jul 2010 18:13

I think the good Col. has misunderstood the TP a little. AFAIK the Mk1 intake itself is enough for the current airflow requirements. a higher thrust engine for Mk2 would likely have higher airflow requirements and might necessitate a larger intake, at least that's the opinion of one informed friend after some calculations.

the side inlets are for quite another reason altogether and the Col has completely goofed up on it. it's a little known fact that the LCA intake is the classic S-shape in addition to being split in Y hiding the compressor fan completely. the side inlets are for energising airflow at high AoA.

nachiket · Post by **nachiket** » 13 Jul 2010 18:28

Rahul M wrote: it's a little known fact that the LCA intake is the classic S-shape in addition to being split in Y hiding the compressor fan completely.

It's actually quite a well-known fact. Not surprisingly though the media is either blissfully unaware of the substantial RCS reduction benefits derived from this (and its importance) or chooses never to highlight it for reasons best known to them.

Singha · Post by **Singha** » 13 Jul 2010 18:31

most fighters have an intake whose bottom edge is far behind the top edge. is this to keep sucking up air at higher AoA as opposed to a
flat on intake like Tejas ? the rafale also has a tejas type intake but notice the two addl smaller inlets at the BOTTOM!
http://img.dailymail.co.uk/i/pix/2007/0 ... 68x280.jpg
http://www.militarypictures.info/d/42-3/FR_Rafale-9.jpg

maybe the soln is to insert two such rafaelish scoop intakes ?

karthik · Post by **karthik** » 13 Jul 2010 18:39

deleted..

karthik · Post by **karthik** » 13 Jul 2010 18:40

Rahul M wrote:I think the good Col. has misunderstood the TP a little. AFAIK the Mk1 intake itself is enough for the current airflow requirements. a higher thrust engine for Mk2 would likely have higher airflow requirements and might necessitate a larger intake, at least that's the opinion of one informed friend after some calculations.

the side inlets are for quite another reason altogether and the Col has completely goofed up on it. it's a little known fact that the LCA intake is the classic S-shape in addition to being split in Y hiding the compressor fan completely. the side inlets are for energising airflow at high AoA.

Rahul, Don't the size of the two intakes correspond to the radius of the engine? I think the engine can take only as much as the Radius of its blades permit, so adding a larger intake may not solve the problem. Do we know if the LCA has variable ramp engine air inlets or bleed air intakes? I cant see any variable ramps on the exterior of the intake of LCA may be there is some thing inside? May be the pilot was referring to one of these systems?

Lalmohan · Post by **Lalmohan** » 13 Jul 2010 18:52

Singha - I might be wrong, but I think its more to do with managing shock waves in the transonic region of flight

karthik · Post by **karthik** » 13 Jul 2010 19:15

Lalmohan wrote:Singha - I might be wrong, but I think its more to do with managing shock waves in the transonic region of flight

I guess thats what the pilot meant.An powerful engine may draw air at super sonic speeds even during subsonic flights and hence choke itself out if the duct is not designed with proper intake ramps? Causing a flame out.

While the aircraft itself is in sub sonic speeds the air intake may be supersonic in high AoA areas because of the extra power needed to push the aircraft from staling itself at these challenging angles. Since the airflow is slow on the aircraft frame but super sonic in the duct region the flow is transonic. It could gasp for more air create an vacuum in the duct region and eventually flaming out, may be someone more learned in this filed could enlighten me.

Does any one know of our LCA has bleed air technique?

Jayram · Post by **Jayram** » 13 Jul 2010 20:31

Intresting - I also think this is a factor being much discussed now becuase of Naval LCA right? In the NLCA - AOA required will be steeper for landing on a carrier and the attendent risk greater with a catastropic engine flameout. I dont really think AOA of > 28 are exprencied in Combat except if TVC is involved right?

shiv · Post by **shiv** » 13 Jul 2010 21:13

Singha wrote:most fighters have an intake whose bottom edge is far behind the top edge. is this to keep sucking up air at higher AoA as opposed to a
flat on intake like Tejas ?

In fact this is not true for most aircraft. "Box intakes" with an upper lip in front became fashionable at one stage and a series of designs appeared one after the other with box intakes. These include the MiG 25, F-14, F-15, Tornado. MiG 29 and Su 27. They are all late 1970s to 1980s designs

In many (if not all) the upper lip that is forward of the lower lip helps prevent the supersonic cone from entering the intake. But box those old intakes were unstealthy

The F-111, F-16, F 18, Rafale. Gripen, do not have box intakes of that sort.

The Eurofighter and J 10 have an upper lip that probably does the same thing for the supersonic cone.

I don't think the angulation has anything to do with intake air at high AoA. In any case the Tejas has a huge portion of wing leading edge extending far forward of the intake and that should be quite enough to scoop air into the intake at high AoA if that were a problem. But I suspect that is not the problem at all.