LCA Tejas: News and Discussions

[srai]

srai, Why do they have 725 liters and 800 liters tanks? Any special need?

Looks like IAF needs to order quite a few of those drop tanks for LCA for future service use.

Good question. From what I was able to gather, this is what it looks to be:

• inner-wing stations -> 2 * 1200-liters drop tanks
• inner-wing stations -> 2 * 800-liters drop tanks
• centerline station -> 1 * 725-liters drop tank (probably due to ground clearance needs)

Both 725-liters and 800-liters tanks could be made use of if they ever decide to adapt drop tanks to the mid-wing pylons.

Supersonic drop tanks are also supposed to be in the 725-liters capacity.

[ramana]

So 2*1200 + 725 L
or 2*800 + 725 L

Max external fuel load.

[Gagan]

The 725L size may also have to do with weapon weights, and MTOW with certain weapons, so perhaps a slightly smaller volume tank.

[Indranil]

The MiG21 specially the earlier models like type74, type 66, type77 could be intentionally spun, though the were not cleared for doing so by the average pilot. However, the exercise was straightforward. Loss of height in the process was substantial. Some of us demonstrated a spin to young MiG 21 pilots but did not ask them to practice it on their own.

Did not know this. Thank you.

^^^ Is there any Delta design which has been spun successfully.? (sorry for OT)

Abhibhushan, As you know the Mig-21 had horizontal stabilizers that helped.
The LCA is tailless delta.
So different animal.

It does not matter whether the plane has a delta wing or a a dedicator horizontal stabilizer. The Mig 21 was stable, i.e. the airframe resists departure from level flight. If a deviation happens, say by a gust of wind, the airframe works towards dampening the same. LCA is an unstable plane., i.e. if a deviation happens, the airframe works towards accentuating the same. More specifically, for LCA the amplitude of the deviation doubles in about 0.2 seconds, i.e. it multiplies by a factor of 32 in a second. Even then, recovery methods are identified. If you read the paper on AoA testing of the LCA, they specify the method. But the pilot is unlikely to be physically able to react that fast. That's why it is avoided.

Other unstable fighters also avoid this and keep a margin of safety. On the F-16, inspite of these margins, under some conditions, the pilot could overload the FCS, and reach a conditions from where the fighter was unrecoverable. The standard operation, is bail out. That is what, most airforces advice their pilots. If you lose sense of orientation, you should bail out. Some fighters have special measures. For example, on the Gripen the FCS leaves the canard "free-floating". In this configuration the fighter is thought to become stable, and the pilot can be expected to fly the plane like a stable aircraft. He is supposed to bring the fighter back to level flight, from where the FCS can take over again. However, this is too risky. Gripen has already suffered a few crashes due to PIO. I read about them long time back, and I don't remember if the above condition was involved in the process.

Indranil, point 1 is same as what I am saying. For point 2, a stable delta like mirage 3 will will get into a turn with nose down and Musharraf up, where by killing lift (apart from any draggy design or low engine power). The whole point of static instability of Lca or mirage 2000 was that they go in turn with nose up ( watch all the videos). But the other point stands, due to g limitation speed comes down, lift gets killed, draggy design does not help and Lower thrust engine further kills it. Mk 2 addresses these. Increases in length is to decrease that drag (there is a graph that shows sudden increase in drag vs l).
On point 3, I have not reAd or interpreted the way you have. My take was that the general push for turning angle was done (without spin coming into picture). There could be news, if you have read that explicitly states that. Point 4 is well taken, but a better understanding of claw around spin will help here.

Good that we are on the same page on Points 1,2 and 4. I don't know what you are asking me regarding point 3. Proof for completion of high AoA tests? They have publicly said it multiple times that they have tested AoA to 24 degrees. After FoC they will push towards 26. Some reporters (including Sjha) reported that 26 has already been achieved. And that they will push it to 28. At 26 or 28 degrees, LCA would have amazing ITR. Actually, nobody is worried about the ITR.

[srai]

The 725L size may also have to do with weapon weights, and MTOW with certain weapons, so perhaps a slightly smaller volume tank.

That may be but AFAIK the centerline station is only integrated with 725L which could mean it was a specific development. I'm not sure if 725L has been integrated with inner wing stations.

[Kakkaji]

Check the Manu Pabby article in the Economic Times. GOI apparently trying to rope in the private sector to design and produce LCA Mk2. I can't post from cellphone.

In other news Parrikar said earlier today that the LCA will replace the Mig21, but it will take about 20 years to replace them all

[shiv]

Abhibhushan, As you know the Mig-21 had horizontal stabilizers that helped.
The LCA is tailless delta.
So different animal.

I guess you are IAF fighter stream?

,
Yes. Air Commodore (retd), senior to my cousin Suresh

[Vayutuvan]

praNAm to Abhibhushan ji.

[Kakkaji]

Yes. Air Commodore (retd), senior to my cousin Suresh

TKSTales?

[Sid]

srai, Why do they have 725 liters and 800 liters tanks? Any special need?

Looks like IAF needs to order quite a few of those drop tanks for LCA for future service use.

Good question. From what I was able to gather, this is what it looks to be:

• inner-wing stations -> 2 * 1200-liters drop tanks
• inner-wing stations -> 2 * 800-liters drop tanks
• centerline station -> 1 * 725-liters drop tank (probably due to ground clearance needs)

Both 725-liters and 800-liters tanks could be made use of if they ever decide to adapt drop tanks to the mid-wing pylons.

Supersonic drop tanks are also supposed to be in the 725-liters capacity.

A quick adaptation will be to simply use ballistic cap on current sub-sonic drop tanks.

[Vipul]

Project to build new, improved version of ‘Tejas’ fighter may be given to private sector.

Frustrated by the persistent delays and design flaws that have dogged the Light Combat Aircraft, or LCA, programme, the government is seriously considering whether to hand over the project to build a new, improved version of the 'Tejas' indigenous fighter plane to the private sector for time bound and efficient execution.

Sources said discussions have taken place in the top echelons of the government on the best ways to inject urgency into the Tejas programme, possibly even with the involvement of a private sector player that would be clearly incentivised to deliver a new aircraft on time and within budget.

Should such a move fructify, it would mean a radical departure in the long­ prevalent approach that only state­run firms could undertake strategic programmes of this nature. This thinking, independent experts say, is yet to give the country a combat­ready modern fighter despite being in the works for more than three decades.

At stake for private sector participants is a potential order for more than 160 improved Tejas Mk II fighters that the
Indian Air Force desperately needs to plug vital operational gaps and which top echelons of the government increasingly feel the state­run agencies involved in the LCA ­ Hindustan Aeronautics Ltd (HAL) and the defence ministry's Aeronautical Development Agency (ADA) ­ do not simply have the capacity to meet.

"It is very clear that the LCA program cannot be allowed to go on as it is. There are not enough resources available to complete the project in the timeline required. A private company would be accountable and would invest in the project," a senior official aware of the government's thinking told ET. This person requested anonymity because of the extremely sensitive nature of the topic. A defence ministry spokesperson said he was not in a position to immediately comment. Officials at DRDO were not available for comment. HAL officials said they were unaware of the discussions.

While the contours of the plan are still being discussed, one thinking is that the Indian private entity selected could take on an international collaborator to redesign the fighter with a new power plant and reduced weight and would be responsible for the timely delivery of the aircraft. Another proposal doing the rounds suggests the setting up of a special purpose vehicle for the project in which DRDO and HAL, the entities now responsible for the LCA, could be partners along with the private sector. A foreign collaborator could also be a part of this.

EXPORT POTENTIAL
"An improved version of the fighter that meets air force requirements would also have a good export potential. The numbers could go up significantly if India promotes it in and around the region as an affordable fighter," another official said. An order of such a magnitude, with each fighter costing a few hundreds of cores of rupees, could pitchfork the Indian private sector player into the global league of military aircraft makers, boost domestic aviation technology capabilities and help with the government's 'Make in India' cause.

The Narendra Modi government has sought to rope in the private sector into defence manufacturing in a big way, clearing a record number of defence manufacturing permits and increasing the foreign investment limit in the sector to 49% and even up to 100% in select cases. The LCA was conceived in the early 1980s as an aircraft that would replace the Russia­ made MIG 21, which for long was the training and combat bulwark of the Indian Air Force. But three decades on, the air force is still to get even a single squadron of these indigenously produced fighters. In contrast, both China and Pakistan have squadrons of indigenously developed fighter aircraft. China in fact has two new projects for fifth generation fighters, with both planes already in test flying stage. Pakistan has an operational indigenously built fighter jet ­ the JF 17 that was developed through Chinese assistance.

The LCA too has had its share of international help. European conglomerate EADS has assisted in the past on the project. government is also considering a proposal by Sweden's Saab to help the LCA's development ­ Saab's fighter Gripen is very similar to the LCA. Despite being more than three decades old, the first of the Tejas fighters was inducted into the air force only last year. While an order for 40 aircraft has been placed, the fighter is still not combat worthy and is expected to receive operational clearance only by the end of this year.

However, even after the clearance, the LCA will not meet the new requirement of the air force, necessitating a Mk II version that would be on par with modern standards. In a recent audit of the LCA program, national auditor CAG had pointed out several deficiencies in the fighter. Its report said that the LCA does not meet air force specifications, is unsafe for pilots and not combat ready. The CAG has listed increased weight, reduced fuel capability, non­compliance of pilot safety norms and reduced speed as some of the critical deficiencies in the aircraft. It also said the fighter had has reduced operational capabilities and survivability which throes questions on its employability in combat.

[shiv]

Yes. Air Commodore (retd), senior to my cousin Suresh

TKSTales?

Yup!
https://tkstales.wordpress.com/

[member_27581]

It's many pubby!

Project to build new, improved version of ‘Tejas’ fighter may be given to private sector.

Frustrated by the persistent delays and design flaws that have dogged the Light Combat Aircraft, or LCA, programme, the government is seriously considering whether to hand over the project to build a new, improved version of the 'Tejas' indigenous fighter plane to the private sector for time bound and efficient execution.

Sources said discussions have taken place in the top echelons of the government on the best ways to inject urgency into the Tejas programme, possibly even with the involvement of a private sector player that would be clearly incentivised to deliver a new aircraft on time and within budget.

Should such a move fructify, it would mean a radical departure in the long­ prevalent approach that only state­run firms could undertake strategic programmes of this nature. This thinking, independent experts say, is yet to give the country a combat­ready modern fighter despite being in the works for more than three decades.

At stake for private sector participants is a potential order for more than 160 improved Tejas Mk II fighters that the
Indian Air Force desperately needs to plug vital operational gaps and which top echelons of the government increasingly feel the state­run agencies involved in the LCA ­ Hindustan Aeronautics Ltd (HAL) and the defence ministry's Aeronautical Development Agency (ADA) ­ do not simply have the capacity to meet.

"It is very clear that the LCA program cannot be allowed to go on as it is. There are not enough resources available to complete the project in the timeline required. A private company would be accountable and would invest in the project," a senior official aware of the government's thinking told ET. This person requested anonymity because of the extremely sensitive nature of the topic. A defence ministry spokesperson said he was not in a position to immediately comment. Officials at DRDO were not available for comment. HAL officials said they were unaware of the discussions.

While the contours of the plan are still being discussed, one thinking is that the Indian private entity selected could take on an international collaborator to redesign the fighter with a new power plant and reduced weight and would be responsible for the timely delivery of the aircraft. Another proposal doing the rounds suggests the setting up of a special purpose vehicle for the project in which DRDO and HAL, the entities now responsible for the LCA, could be partners along with the private sector. A foreign collaborator could also be a part of this.

EXPORT POTENTIAL
"An improved version of the fighter that meets air force requirements would also have a good export potential. The numbers could go up significantly if India promotes it in and around the region as an affordable fighter," another official said. An order of such a magnitude, with each fighter costing a few hundreds of cores of rupees, could pitchfork the Indian private sector player into the global league of military aircraft makers, boost domestic aviation technology capabilities and help with the government's 'Make in India' cause.

The Narendra Modi government has sought to rope in the private sector into defence manufacturing in a big way, clearing a record number of defence manufacturing permits and increasing the foreign investment limit in the sector to 49% and even up to 100% in select cases. The LCA was conceived in the early 1980s as an aircraft that would replace the Russia­ made MIG 21, which for long was the training and combat bulwark of the Indian Air Force. But three decades on, the air force is still to get even a single squadron of these indigenously produced fighters. In contrast, both China and Pakistan have squadrons of indigenously developed fighter aircraft. China in fact has two new projects for fifth generation fighters, with both planes already in test flying stage. Pakistan has an operational indigenously built fighter jet ­ the JF 17 that was developed through Chinese assistance.

The LCA too has had its share of international help. European conglomerate EADS has assisted in the past on the project. government is also considering a proposal by Sweden's Saab to help the LCA's development ­ Saab's fighter Gripen is very similar to the LCA. Despite being more than three decades old, the first of the Tejas fighters was inducted into the air force only last year. While an order for 40 aircraft has been placed, the fighter is still not combat worthy and is expected to receive operational clearance only by the end of this year.

However, even after the clearance, the LCA will not meet the new requirement of the air force, necessitating a Mk II version that would be on par with modern standards. In a recent audit of the LCA program, national auditor CAG had pointed out several deficiencies in the fighter. Its report said that the LCA does not meet air force specifications, is unsafe for pilots and not combat ready. The CAG has listed increased weight, reduced fuel capability, non­compliance of pilot safety norms and reduced speed as some of the critical deficiencies in the aircraft. It also said the fighter had has reduced operational capabilities and survivability which throes questions on its employability in combat.

[srai]

^^^

It's another one of those planted articles.

Why don't the private players start with something basic first like BTT or IJT or Saras? Have them partner with HAL or NAL. Baby steps.

[shiv]

It's many pubby!

Project to build new, improved version of ‘Tejas’ fighter may be given to private sector.

This article has been written by a person who thinks that building a combat aircraft is like sperm donation. If your sperm ain't working fast enough for you, get a private contractor to donate his sperm.

[Hobbes]

....
This article has been written by a person who thinks that building a combat aircraft is like sperm donation. If your sperm ain't working fast enough for you, get a private contractor to donate his sperm.

Apologies for the OT, but I just couldn't resist it.
The Growing Market of Free Sperm Donation

For those who can’t afford the expense, there is now a growing alternative of independent contractors that make up an on-line gray market of free sperm donors.

[ramana]

Wow. I am a fan of tkstales. thanks for your presence.

No private contractor will build a factory for 160 planes and have a design from someone else.
Good thing the source was unnamed for he will die of ridicule.
One reason why US contractors have long runs with a product.

indranil, Mig-21 horizontal stabilizers helped a lot. Grand daddy of all these canard aero vehicles in the Navaho cruise missile. Mig-21 used rear horizontal stabilizers.

[Vayutuvan]

160 cars can be built by hand which they do for Italian autos like Lamborghini and Ferrari. Aircraft? Probably that also can be done. One needs very good artisans though.

[member_27581]

OT but Sometimes I wonder whether these people have any have any feeling of pride about things made in India or is it just the lifafa speaking. If auditors start reviewing F22 they will find flaws there too, because that's their job.

Had it been made in any propaganda state, it would have been touted as the best fighter on earth, pride and backbone of IAF and what not. Alas!

However, even after the clearance, the LCA will not meet the new requirement of the air force, necessitating a Mk II version that would be on par with modern standards. In a recent audit of the LCA program, national auditor CAG had pointed out several deficiencies in the fighter. Its report said that the LCA does not meet air force specifications, is unsafe for pilots and not combat ready. The CAG has listed increased weight, reduced fuel capability, non­compliance of pilot safety norms and reduced speed as some of the critical deficiencies in the aircraft. It also said the fighter had has reduced operational capabilities and survivability which throes questions on its employability in combat.

[rohitvats]

So 2*1200 + 725 L
or 2*800 + 725 L

Max external fuel load.

Aha! CAG Reports comes to rescue and helps clear weight issue.

Page 18 of the report has picture with load classification for each pylon (Inner to outer pylon):

- 1200 kg + 800 kg + 150 kg
- Center line - 1200 Kg
- 7th station for LDP - 200 Kg.

So, as Srai mentioned, unless there is ground clearance issue with 1200 Liter drop-tank, we can have 1,200 x 3 tanks for ferry range.

[ragupta]

It's many pubby!

Project to build new, improved version of ‘Tejas’ fighter may be given to private sector.

Frustrated by the persistent delays and design flaws that have dogged the Light Combat Aircraft, or LCA, programme, the ......

Nice move, about time this is tried. With due respect to DRDO/HAL/ADA, this process will help LCA and other indigenisation effort.
Private company can bring in resources, solution, faster absorbtion of technology, alternative option, etc... their decision making will be overnight compared to months with the govt bureaucratic process.

This is a positive move, private public synergy is needed in the MIC area, to make sure indigenization picks up pace. I am sure it will reduce headache for ADA/HAL/DRDO in dealing and getting every decision passed and cleared through MOD. I am expecting this to reduce decision making process and product testing expedited.

[Pratyush]

The pvt contractor for LCA report nicely ties up an earlier report where the GOI was looking for a pvt player to make 250 Mk2s. They had budgeted 12 billion $ for the enterprise.

But this was not followed up with at that time. This seems to be a follow up to that news.

[srin]

If it is just to produce the aircraft, then it is fine.

But if they (or a foreign collaborator) are called into "help" design the Mk-2, then it is going to be a big mess with no clear owner, lot of committees and no product at the end of it. Bye bye Mk-2

[JayS]

This has been discussed in great detail. Go here for all the technical details. What followed was a few pages of studying the papers from ADA/NAL. Nileshjr can tell you more.

@Nilesh, let's get that document going again. Can you please post the link to that online document again.

Here is the link:

https://docs.google.com/spreadsheets/d/ ... sp=sharing

No one has entered anything so far.

[JayS]

Moreover LCA has same FCS operating on 4 channels with same hardware. It has worked fine, but other planes use different FCS with different hardware and the computer always poll and take the action recommended by the most FCS. This is something that should be worked to make this thing more robust.

When you say "different FCS with different h/w", what does the FCS in that means exactly?? Control Laws?? and what different h/w components you are referring to (flight computers, wire channels, actuation system)??

[NRao]

After Bofors, defence ministry to purchase guns again: Parrikar

Parrikar, who was in Lucknow to attend the training programme of elected cantonment board members, said that defence ministry would also begin the process of replacing MIG 21 fighter jets with indigenously built Tejas. However, he said that it would be a gradual process and replacing a large fleet would cost more. The process of replacing MIGs with Tejas would be done over a period of 20 years or so, he added

Limiting factor is cost of replacing? And not production rates?

So, now we can compute the production rate for the LCA:

* 240 planes: 12 per year
* 400 planes: 20 per year.

[vina]

When you say "different FCS with different h/w", what does the FCS in that means exactly?? Control Laws?? and what different h/w components you are referring to (flight computers, wire channels, actuation system)??

Ideal case, you want two teams to be developing the software totally independently of each other , the control laws to be different, the computer architecture and even hardware to be different. For e.g., the "key" part of what was confiscated by Unkil after Pokhran was the computer & FCS. The F16 for e.g., I think uses one analog channel. That is what they were supposed to contribute to the LCA, the analog part and which we didn't. Anyways. This is a non issue now.

[shiv]

Ideal case, you want two teams to be developing the software totally independently of each other , the control laws to be different, the computer architecture and even hardware to be different...This is a non issue now.

Back in the old days, when FBW was new this is the story we were told. I mean - the impression that we were supposed to get was that these guys are so so careful and so so reliable that they get two whole different independent teams to write the software - and that the FBW system working from these two sources has to agree other wise a master program will say "Balls to you" and default to some fail safe something.

I think that story was current when everyone was suspicious of computers and software. I think it is a non issue now. I would have thought that thoroughly debugging one set of codes is netter than allowing two different sets in the hope that two teams would have made different errors if any. I mean do they ever do this for the software that controls nuclear missiles? Imagine one drunk and stoned team of software writers whose code points the missile straight back at the launcher. I just wonder if this "many teams" things was extra drama for that day and age when perhaps thoroughly debugged modules for various functions were unavailable.

I don't know. I am writing this in the context of some stupid article I read claiming that all 4 sets of LCA code are from the same team as if that is like cousin marriage leading to rat brain ammi-abba LCA. Flippin heck the LCA test history has been the most accident free combat aircraft development in history and who are these mofos who speak like oiseaules?

[JayS]

Ideal case, you want two teams to be developing the software totally independently of each other , the control laws to be different, the computer architecture and even hardware to be different. For e.g., the "key" part of what was confiscated by Unkil after Pokhran was the computer & FCS. The F16 for e.g., I think uses one analog channel. That is what they were supposed to contribute to the LCA, the analog part and which we didn't. Anyways. This is a non issue now.

Does any plane made so far in the world has two Control Laws made?? I have never seen this particular point made by Fanne wrt LCA FCS before. So I am interested in this.

4 Computers with 4 data buses is the norm i guess. DFCC would be one only as if has to compare the 4 signals and integrate them into single actuation command. Ideally you should have 4 input sensor sets for aerodynamic parameters but that would be too much unnecessary efforts I guess. LCA has 2-3 sets of each sensors like pitot tube etc IIRC, so some redundancy is there in Inputs.

Also AFAIK, LCA was never planned with one analog channel. ADA rejected Dassualts proposal precisely because they had one analog channel whereas the Americans (LM) offered fully digital system. I hope I my memory serves me well here. Also F-16 had analog channel initially in A/B versions, not anymore. That's what wiki says.

Also I remember to have read this remark on FCS testing (in think in P Rajkumar's book) that the probability of failure in these digital channels is so less (~10^-7 or something like that) that failure of multiple channels is even remote. So much so that BAE wouldn't even test failure mode when 3 of the 4 channels fail, only 2 failures would be tested.

Damage in dog-fight etc is a different story though. All these computers are stored in single LRU in case of LCA. I don't know if this is the case with other fighters as well. Keeping them apart might be good idea, or it might be unnecessary trouble. I wouldn't know.


This paper talks about the s/w V&V process for LCA FCS. You can see some of the pages of the paper. Gives some idea about the rigor they follow. Its an old 2003 paper and by now the process must be even more robust. Till 2003, the paper says, not a single s/w bug was encountered in-flight.

https://books.google.se/books?id=FIWzec ... em&f=false

[deejay]

Is there any Delta design which has been spun successfully.? (sorry for OT)

Yes Deejay, The MiG21 specially the earlier models like type74, type 66, type77 could be intentionally spun, though the were not cleared for doing so by the average pilot. However, the exercise was straightforward. Loss of height in the process was substantial. Some of us demonstrated a spin to young MiG 21 pilots but did not ask them to practice it on their own.

Thank You Sir. I had read an old post of yours which was a letter to your grand daughter. I had saved the post with me. I was greatly intrigued and I am delighted to learn that the source of the wisdom is a Veteran.

[Kakkaji]

Guys, read between the lines on the Manu Pabby article. It is about getting the Gripen in through the back door, by letting SAAB take over the further development snd production of LCA Mk2 with a private Indian 'collaborator' company in front.

[vina]

Does any plane made so far in the world has two Control Laws made?? I have never seen this particular point made by Fanne wrt LCA FCS before. So I am interested in this.

Yes. I think the F16 and probably the Gripen , which directly inherited the F16 FCS. The F16 I think has 2 digital channels and one analogue channel I think , not sure though. Google around for details .

[Singha]

i read about a decade ago that airbus uses different teams (walled from each other), writing in different language, using different toolchain and HW using different cpu and architecture for its main FCS. this is to reduce chance of same human error, or shared code, or HW defect taking out the entire system. this is a sound idea, for example take the unix system calls in some C library..., or utilities in libc...everyone uses them...python libs implemented in C might use them too.

it is mentioned here http://www.slideshare.net/sommerville-videos/airbus-fcs

needless to say one just not be able to pull a github repository , hack something on a friday night over a couple beers, fall asleep in the seat, wake up and make love to the delectable gf, sleep again, and code commit with no review the next morning over a coffee and bagel

they must be keeping a cast iron checkpoints, change logs and paper trail for each character of change to such code.

[Vayutuvan]

That was true for space shuttle as well. There was an article in sciam or CACM. One pair of computers plus software was from IBM and another pair from Rockwell. There was no communication between the companies/teams, completely walled off from each other.

[Singha]

probably for military planes the requirements are not as stringent ....

[JayS]

Does any plane made so far in the world has two Control Laws made?? I have never seen this particular point made by Fanne wrt LCA FCS before. So I am interested in this.

Yes. I think the F16 and probably the Gripen , which directly inherited the F16 FCS. The F16 I think has 2 digital channels and one analogue channel I think , not sure though. Google around for details .

In the previous post only i mentioned that F-16 has quad-plex digital system. They don't use analog system anymore. Same goes for Gripan.

Also, different FCS means only two different codes of same control laws (physics) I presume.

[Singha]

control laws being purely defined by physics would be the same in any language of implementation I suppose.

[fanne]

Nileshjr ji,
The CL is also different (though flying follows law of nature, and any model you built, if it conforms to that, will fly the plane and provide the same output). The crudest CL is of course the conservation of momentum (in three axis) and conservation of energy. This wont fly the plane as you have more variables and less equations (4). From public info, LCA uses grouped scenarios where input and output are defined (and I suppose some kind of equation that smooths that up over the whole flight envelope). Once when I was chasing CLs (about a decade ago), there were hints of more sophisticated Cls. The ultimate would be something like law of nature (like Newtons law), where you can stick the same Cl to all planes and it will guide it, but that is easier said then done. Again my understanding of whole of this subject is very amateurish at best.

[Philip]

Looking at the latest depressing news,I am getting more convinced that Tejas will never replace the MIG-21s being retired.We will have to go for imports as developing a new MK-2 with firang help + pvt. sector with NO experience of aircraft manufacture will be an unmitigated disaster!

I can't understand why the GIOI/MOD is not reading out the riot act to the ADA/HAL whoever is responsible for this fiasco? and sack the bl**dy top man/men whose responsibility it is.Putin does it,other nations too,and they get results. Why can't HAL deliver the goods when it is manufacturing MKIs,Hawks,Jaguars,etc.? First reform HAL and the desi aircraft industry and results will swiftly follow. Getting a pvt. player is passing the buck and absolving HAL and the ADA of incompetence.

As for MIG-21 replacements,just order a efw MIG-29 sqds. as an interim measure,while a kick-ass/firing squad policy is conducted in the higher echelons of the LCA programme.

PS:What then happens to the tiny order of the IN,the NLCA?

[tsarkar]

So? Boss, all throughout I have been making the EXACT point that the AF led decision to keep the TDs as science lab programs was FLAWED thanks to their desire to keep the program in a very "lets see and then decide manner" which is where the entire development process was doubled since basic technology had to be reworked or added in much much later.

Karan, your gripe is that IAF was “lets see & decide” mode for TDs instead of working in parallel to expedite matters.

In reality, things that needed to progress linearly had to be done linearly. There was no other way of doing it. And whatever could’ve been done concurrently, was done concurrently.

For example, when the TD’s were being built, adding systems to it would’ve been meaningless, because TD’s were built to prove & test the basic flight characteristics of the airframe.

Only once the flight characteristics were proven, could adding systems progress.

From ADA http://www.tejas.gov.in/history/genesis.html[quote] Phase 1 - TECHNOLOGY DEMONSTRATION STAGE (TD-1 & 2) The focus in this phase was on ‘proof of concept’. It entailed the development and testing of two technology demonstrator aircraft. These aircraft were called TD-1 and TD-2. The decision to move forward was to be taken after the successful completion of this phase. This would be followed by the production of additional prototype vehicles. [/quote]
Now this was not something IAF could’ve helped with, this is just basic project management. Its only after a house’s foundation is laid and basic structures like pillars & floors are in place that one can start working on laying electricity cables, water, gas & sewage lines, doors & windows.

In proof of concept phase, in any project, anywhere in the world, everyone, and not just IAF, has to work in "lets see and then decide manner". And as underlined as per ADA, everyone was "lets see and then decide manner".

If the IAF team had been part of the TD process itself & the TD process was not merely a "demo" but worked on in parallel with a clear roadmap (as versus waiting for FSED approval) we would have saved a heckuva lot of time.

As I’ve said earlier, Proof of Concept cannot be worked in parallel, like adding systems when the airframe characteristics are yet to be proven.

However, everything that could be done concurrently was done concurrently. Like MMR Radar development, Kaveri engine development, RWR development, etc.

Again, from ADA http://www.tejas.gov.in/history/genesis.html[quote] Phase 2 - ADDITIONAL TESTING PHASE (PV-1, PV-2, PV-3 and PV-5)
This phase consisted of additional testing and development of systems using Prototype Vehicles which would lead to the development of the final variant that would join the IAF and the Indian Navy. The first Prototype Vehicle, PV-1 flew on 25 November 2003.

By 2005, the Tejas had proven itself in the testing phase and the first order for 20 Series Production aircrafts was placed. A follow on order for an additional 20 SP aircraft was placed in 2010. [/quote]

IAF requirements except weapons did not change. CAG is clear on that. Other than that, nothing from IAF delayed the project.

The “heckuva lot of time” was what it actually took to develop the Tejas by ADA.

Even the MMR (Multi-Mode Radar) underwent changes after the indigenous effort to make one did not succeed. So we had to go for Israeli Elta Radar.

The Hybrid MMR is NOTHING but an ELTA 2032 with an Indian scanner.

The reason I posted this was whenever IAF uses a foreign system, many forum members like characters from the “Lord of the Flies” viciously accuse them of being under the influence of Natashas without any reason or logic. However, when ADA Chief says his system is ELTA instead of Hybrid MMR, the same forum members are conspicuously silent. In SP aircraft, fully integrated radars will be imported from Israel, without any Indian antenna. ECIL did build antennas that were used in testing, but in production, decision was taken for a single manufacturer to avoid integration issues.

The point all along which you don't seem to get is that the TD ->PV development choice was FLAWED to begin with

Your statement is grossly incorrect. It was ADA & everyone’s decision, and normal Engineering Development to do a PoC and build the TD’s and thereafter PVs.

since the IAF did NOT specify proper specifications for the TDs themselves to do the heavy lifting

Your statement is again incorrect, since IAF specifications existed since 1985.

And it was everyone’s decision to build TD’s as PoC and thereafter build PV’s with combat systems.No one builds mission systems into unproven PoC systems

As such everything had to be redone.

Further incorrectness.

Can you enlighten us specifically what “everything had to be redone”?

LOL, here I was pointing out that this was the exact flaw in the program that the TDs didn;t have adequate mission capable systems and you are repeating my words.

Hope you’ve understood by now that Proof of Concept Technology Demonstrators by deliberate design don’t have mission capable systems. They are just for proving concepts like basic airframe characteristics. And its got nothing to do with IAF.

Next you just posted a list of handful of items and even there you are wrong. TD's didn't have MFD? What were they flying with, steam gauges? The TDs had a complete mission computing, display suite which experience was used for upgrade programs.

http://www.tejas.gov.in/history/milestones.html[quote] 2006
1st December - PV-3 flew for the first time for 27 minutes at an altitude of 2.5 km and at a speed of Mach 0.8. PV-3 was equipped with a more advanced pilot interface, refined avionics and higher control law capabilities compared with the previous versions. [/quote]

The IAF choosing the flawed TD to PV model ensured the actual FSED started much much later.

No, its your understanding of Program Management & Engineering Development that is horribly incorrect and flawed, as explained above.

I could even post a list of changes from my own notes but this is ending up as a waste of time.

No, please post. Would love to be enlightened if you have any further information.

In the case of the LCA, the IAF happily let things slide till 2005 before which they werent bothered with the program and hence it took FSED to actually make the LCA into a combat aircraft. As versus having done a fair amount of the heavy lifting by TD stage itself and not using this sequential process to begin with!! IAF came up with high level specs & then disassociated themselves from the program till 2005-6. "AF goalposts didn't change" except the fact that only they knew what their specific interpretation of many of these goalposts would be, which is typical for a program of this nature. The IAF appointee to the program recently noted that the IAF joined in 2006 and reworked all the design logic and raised hundreds of engineering change requests for the program to make it a viable program. All good, but thats five years after 2001!

The prevalent culture in the 80’s & 90’s was anything but collaborative. Air Commodore Sen has written extensively how talented people like Air Marshal PM Ramachandran recommended by A P J Abdul Kalam were interested in joining the program.

https://tkstales.wordpress.com/2012/04/ ... s-arrives/

By 28 Feb 1993 Ramu had reached his age of retirement. He was then a full Air Marshal holding the post of Vice Chief of the Air Staff. Dr Abdul Kalam was then the SA to RM. He wanted Ramu to take over the LCA project in the existing vacancy of Director General ADA as he had done good work earlier on the very successful “Jaguar Darin” project. Ramu was willing to take on the challenge provided his name was proposed jointly by DRDO & Air Force so that he was not identified as an “Air Force” man or a “DRDO” man and he could function freely in the interests of the project. Accordingly, the SA to RM routed the file through the CAS who concurred with the proposal and forwarded it to the RM Sri Sharad Pawar in Feb 93. It is learnt that the same got approval from three out of the four members of the Appointments Committee of the Cabinet (ACC) within a couple of months but was held up by the PMO for more than two years on various pretexts. It was examined by a few more search Committees all of whom had concurred with the original selection of Ramu. Dr Kalam intervened again and Ramu’s appointment was finally cleared by the PM in Jun 95. The file was then passed to the Establishment Directorate for issue of an official letter of appointment. Even after another one full year, this letter had not been issued. It looked as if no one other than Dr Kalam was interested in strengthening the LCA project Management, and even he was powerless to enforce his will in the face of departmental apathy/antipathy.