LCA: News & Discussions - October 2016

[brar_w]

There is unlikely to be any difference in overall cost to go down the Typhoon route or the Rafale. The entire single engine acquisition seems to point that a simialr MII effort vis-a-vis the rafale is unaffordable. At least it better be or else the case for actually floating a different set of requirements specificly eliminating the two most expensive options in the MRCA would actually not exist.

[JayS]

Vina, concurrent engineering works only when there is maturity in all domains and you get everything right in the first iteration.

But one has to realise that without concurrent engineering of some sort, one has to deploy large amount of resources to iron out all the problems before the production starts, if one wants the entire program to finish in reasonable time. Else while trying to solve a design puzzle serially which is essentially a coupled problem, it would take too much time to finish.

Also your point of view is that of a user, which is fine. But if the program is forced to run this way it will end-up ultra-conservative in design, making it difficult to keep up with the technology, because the designers will have to go back to conservative design and analysis methodology to cut down risks. For better design in every new generation, design methodology has to be upgraded. And it takes time to see the effect of certain things in real life which validates the methodology. Ideally this should happen in Science projects, its difficult to replicate real life situations in lab and to have real life science projects costs a significant money. Today even in US funding for such projects is diminishing. India doesn't even have anything in comparison. So there is no choice but to deploy some of those methodologies without enough validation. But even this happens in very conservative manner in Aerospace.

You have taken this F35 example out of context. The cracks have appeared in durability tests at 9400hrs which is already more than the designed 8000hr life. They have to show total 16000hr operations to find out precisely such problems and increase factor of safety on critical locations. By this standard, A single LCA should be flown for 6000hrs and checked for each and every crack. How many years will that take for LCA then to start production?? How many years it would have taken LM to start production of F35, if they waited for entire 16000hrs of flight program on single prototype?? Even if they had flown the prototype 5hrs everyday, it would take them good long 10-12years. Even with accelerated testing it would have been quite a long time. Even then the failure is of precisely one article which is statistically insignificant and simply could have been due to some inherent fault in this one particular part. Of coarse, this will still be considered as a nominal failure and will be accounted for. The jets which are already build will simply need to go through a thorough bulkhead check for cracks in its overhauls to make sure its fit for operations till next check. I understand you perhaps used this example to highlight your point, but then assuming that such serious problem which will jeopardize operational ability of jet will not be caught during design phase is little far-fetched IMO. Design methodology in Aerospace is ultra-conservative and there are multiple checks to catch such problems. The probability of leaving out some very serious design faults is almost nil since such critical features in the a/c are designed for extremely rare conditions which are expected to occur only once in life time for the entire fleet. And even at those conditions the part should not fail by design. Add to that some more Factor of safety on account of uncertainty in the design methodology which always shifts the design on conservative side.

Anyway It looks to me the issue with life prediction methodology. The Aero industry is moving to probabilistic lifing methods which are new design philosophies. Here designers try to design for manufacturable product and not an ideal one which is almost never produced however TFTA the manufacturing may be. There will be always deviations. Of those deviations are considered in design phases not only the design becomes far more robust, but also non-conformances in manufacturing are reduced significantly. Now these methods are cutting the slice of conservationism that was in-build in previous methods, enabling designers to achieve better and better performance and reliability. (The life extension we see in old gen aircrafts is not because they are built better than expected, they were actually over-designed. This margin of over-design will go down as we progress). Such methods need validation in real life. Lab experiments are simply not enough. To me it looks like LM predicted certain life based on certain method in 1990s which were cutting edge then and when the part was put in real life use the method turned out to be less accurate than expected (actually it still gave life better than design life, so in a way its not a failure at all, but lets say it was expected to last 16000hrs by LM). There would have been no way but to actually build many nos of aircraft and fly it for so many hours and see if cracks or not. Ideally you cannot also do it with one prototype. The results need to be statistically significant. Means number of specimen needed. But in reality this is impractical so you consider such one of results as nominal results and change designs accordingly. This keeps you on conservative side. With this experience the methods will be fine-tuned and next iteration would be much better. Whenever new methods, new materials are used there will be a phase of uncertainty involved. One simply cannot eliminate all these problems beforehand in practice.

Like it or not concurrent engineering is the future. We have to figure out how to do it properly. And lets not forget that Aerospace is the cutting edge of Human Technology. New things will be tested here. There is no escaping from that either.

[saumitra_j]

Vina,

Kakarat has already pointed out the how foreign technologies is used in most of the examples you gave (Bajaj, TVS, Tatas). When I say India designed engine, I don't care if it is all made by one company or multiple company through consultancy - point is that critical knowledge of design and manufacturing (As APJ Kalam had said, Know How and Know Why) does not yet fully exist.

Shiv Saar, the Revotron engine is akin to the Shakti engine in Dhruv - there are Indian design inputs and assembly but know why in critical areas is still not there.

Anyway don't want to go off topic discussing IC engines in Tejas thread.

cheers,

Saumitra

[Neshant]

What can Navy do if HAL AR&DC does not get the landing gear impact strength, weight & volume optimized in the first iteration?

Water down impact load requirements? Then the plane wont be able to land on a carrier

Waive off weight requirements? Then the plane wont be able to take off from a carrier with a useful load.

Its not a trial and error process. Loads and tolerances can be calculated and even simulated in CAD software.

You can certainly narrow down the design variation to the point where you have your best solution fabricated and deployed while other variants to either side of that curve are pre-designed and ready to be fabricated depending on the outcome of tests.

The tests meanwhile are supposed to provide predictive data used for the above decision making.

Of course if all you do is just build it and go through endless cycles to see if it breaks without capturing and analysing the data, then yea it could take a million years to design anything.

[shiv]

Its not a trial and error process. Loads and tolerances can be calculated and even simulated in CAD software.

You can certainly narrow down the design variation to the point where you have your best solution fabricated and deployed while other variants to either side of that curve are pre-designed and ready to be fabricated depending on the outcome of tests.

The tests meanwhile are supposed to provide predictive data used for the above decision making.


Of course if all you do is just build it and go through endless cycles to see if it breaks without capturing and analysing the data, then yea it could take a million years to design anything.

Beautiful piece of writing that ignores an entire encyclopaedia worth of information because even I with zero knowledge of engineering and not one millisecond worth of experience as an engineer will be able to say all that from just the general reading I have done

I will post only 2 points that come to mind
1. If, after all the clever simulation followed by fabrication of the most optimal solution, the gear fails and a prototype Tejas is destroyed, what would Plan B be?
2. Is there any information that endless cycles of real-life testing is made redundant after the assumed optimal solution is reached and that simulated optimal is always and forever the optimalest optimal?

[Neshant]

It's not tested with the plane right off the bat. It's tested with a dummy load representing the aircraft and conditions that add to the stresses on the aircrafts undercarriage. Typically a test rig drops the aircraft with increasing loads and strain guages measure the impact force, sheer stresses and numerous other parameters. It's tested at varying angles of drops on inclinations of various grades..etc etc. For naval aircraft, the enormous force of a ship as it heaves upwards in a wave against a 7 ton aircraft coming down on the landing deck have a whole different additional set of tests.

The captured data is fed into models and measured against the simulated model. Overall it gives a pretty good indication of the characteristics of the landing gear and how well the design holds up.

The variables in this case are largely known unlike designing a fly by wire system.

[JayS]

Folks do not forget that, the overweight LG for NLCA was mainly due to a higher sink rate assumed for the design.

[vina]

Vina, concurrent engineering works only when there is maturity in all domains and you get everything right in the first iteration.

If you do not get some or all things right in the first iteration, then concurrency goes for a toss.

No you don't . Every design, of every component goes through a design spiral iteration. What concurrent design does mean is that the design, review, make, test and iterate loop is much faster because you have factored in manufacturability and requirements rejig must faster.

Concurrency definitely does not work when you're doing something for the first time and the chances of getting it not right is high.

Even with seasoned developers, concurrent engineering carries risks. Take the following example of cracks in F-35 bulkhead

We are talking different things here. There is concurrent engineering and it's more extreme versions. LM took this to the extreme where they did concurrent design AND manufacturing without a full LSP series and structural test specimen maturity. You don't have to do it. You can do just the design upto the LSP stage concurrently and you would have go the overwhelming bulk of it right and factored in manufacturability and maintenance. You do the LSP and another design/fix iteration to reduce risk before going full scale production. Problems such as you mentioned as getting 3 different teams to do modification in 3 different stages would go away in a huge way. You definitely wont have to move around LRUs and cabling and hydraulics etc. AND you probably would have nailed the requirements, right , and made allowance for growth in that in your design..

There was no other way to design the landing gear but iterative. The traditional waterfall method

We are talking different things here. All design goes through iterations , irrespective of the management system behind it. I also mentioned it long ago to someone here in this thread. Just because , you do a Finite Element Analysis of even a simple beam on a computer, it doesn't mean it doesnt do a design iteration. It does! Just as you would break up a beam into two elements first and then break the two into 4 and so on until you build fidelity , when you do the FEM by hand manually like in a class room exercise, the CAD program does the exact same thing!

if they did concurrent engineering and designed a lean landing gear, and it didnt meet its primary function of absorbing the impact, and this was discovered later, then all prototypes and production units built would need redesign and rebuild. That would've further slowed down the program.

Please refer to the comment about F35. We are talking about different things.

This is an incorrect emotional rant on your part.

Far from it. What I mean by dropping the ball is not getting fully involved when it went from TD to FSED stage. That is exactly where the IAF should have stepped in. I pointed out the weapon spec mismatch here, which required wing redesign and set the program back by 1 year. Let me also point out a few things more than Arup Raha Harrumphed about recently as "improvements "

Asked for provision of growth for AESA. Asked for higher fuel load and range, asked for airborne refuelling,asked for IR tracker, asked for internal SPJ (they had already done the Bison upgrade by then, they knew that an SPJ was needed), asked for higher thrust engine. IF they had done that at the start of FSED phase, the LCA that would have come out would have the mould line of the proposed MKII right from the beginning and NOT the current Mk1 version! There would have been a fuselage stretch for extra room for equipment and fuel, aero refinements to match that ask and you could have fielded a version with a normal radar like the MK1 but with an airframe that incorporated the stuff you wanted , you have got a right sized airframe and not come and Harrumph and try to derail the program at the last minute saying oh, I want an INTERNAL SPJ! Where the hell were you guys at FSED stage , when the plane is basically getting re-engineered?

Point is wherever Tejas is today, its because of everyone's hard work. It has happened with all the speed it could. 9 women conceiving wont deliver a baby in a month.

Correction. It is what it is today, DESPITE the IAF , who basically set it up to fail. It is to the credit of ADA and others that they succeeded despite that. Same case with Arjun. It succeeded DESPITE the Army.

[Kakarat]

Vina,


Shiv Saar, the Revotron engine is akin to the Shakti engine in Dhruv - there are Indian design inputs and assembly but know why in critical areas is still not there.

Anyway don't want to go off topic discussing IC engines in Tejas thread.

cheers,

Saumitra

I apologise for continuing this off topic discussion

While I posted that most of the TATA HCV engines are of foreign origin I also said that TATA had developed its own LCV engine which include TATA Ace and one type of Indica engine. Revotron is also TATA specific, they had the piston company design the piston to there spec and involved in testing along with suppliers of various engine parts. There may have been consultants but TATA developed the engine along with parts suppliers. Even Mahindra and TAFE (simpsons) develop there own engines. It is not that India doesn't have capability to develop its own engine

[Neshant]

Let me also point out a few things more than Arup Raha Harrumphed about recently as "improvements "

Asked for provision of growth for AESA. Asked for higher fuel load and range, asked for airborne refuelling,asked for IR tracker, asked for internal SPJ (they had already done the Bison upgrade by then, they knew that an SPJ was needed), asked for higher thrust engine. IF they had done that at the start of FSED phase, the LCA that would have come out would have the mould line of the proposed MKII right from the beginning and NOT the current Mk1 version! There would have been a fuselage stretch for extra room for equipment and fuel, aero refinements to match that ask and you could have fielded a version with a normal radar like the MK1 but with an airframe that incorporated the stuff you wanted , you have got a right sized airframe and not come and Harrumph and try to derail the program at the last minute saying oh, I want an INTERNAL SPJ! Where the hell were you guys at FSED stage , when the plane is basically getting re-engineered?

A simple way to prevent the endless shifting of the goal post by clueless guys like Anup Raha is to force the IAF to invest it's annual budget into the LCA program. Any disruptive design change to the LCA should be met with a heafty bill for the change being sent directly to the IAF. As the budget for the IAF progressively gets destroyed by this management incompetence, the IAF personal will hopefully begin to put an end to this if for no other reason than their salaries have to be downwards adjusted to meet the expense of these massive bills.

But certainly Anup Raha who is the point man for the RFI to sink the LCA is a name to watch for. I'm certain the guy will go on to create many disasters during his reign as IAF head.

[tsarkar]

Like it or not concurrent engineering is the future.

Models are chosen as per circumstances and even for Tejas, it was never a mutually exclusive either/or Waterfall/Concurrent model. There was concurrency wherein radar and engine development proceeded concurrently. Even different PV's and LSP's were tasked for different tests http://www.tejas.gov.in/history/milestones.html

PV-3 was equipped with a more advanced pilot interface, refined avionics and higher control law capabilities compared with the previous versions.

PV-2 and PV-3 underwent sea-level trials at INS Rajali Naval Air Station, Arakkonam to study the effects of flying at sea-level, as all earlier trials have been conducted at Bengaluru which is 3,000 feet (910 m) above sea-level. The reliability of the LCA systems under the hot and humid conditions, as well as low level flight characteristics was tested.

Tejas Prototype Vehicle (PV-1) made a successful flight with two external drop tanks of 800 Ltrs capacity

Tejas PV-1 fired R-73 (CCM) missile for the first time. The trials were conducted off the Goa coast at INS Hansa Naval Air Station.

LITENING targeting pod was successfully tested on Tejas PV-2.

LCA Tejas prototypes PV-2 & PV-3 underwent hot weather trials at Air Force Station, Nagpur.

PV-3 and LSP-2 completed the high altitude test at Leh, world's highest operational airfield.

October - PV-3 and LSP-2 completed air-to-ground weapons delivery trials.

Tejas speed envelope expanded to 1350 km/h (CAS) while performing flight flutter test in a dive to near sea level. These tests were conducted at INS Hansa, Goa.

LCA Tejas LSP-3 made maiden flight. LSP-3 is close to the final configuration including the new air-data computers. Multi Mode Radar, new communication and navigation equipment and radar warning receiver.

First Flight of LCA Tejas LSP-4. Flight. In addition to the LSP-3 standard of preparation, the aircraft also flew with the Countermeasure Dispensing System.

But certain things have to happen iteratively and there is no avoiding that.

Its not a trial and error process....

I'm sure the people on the job are much smarter than me & you, and they would've use CAD and CFD and other mathematical and statistical simulations before plate cutting.

There is a very practical problem with simulation. Simulation is as good as the parameters you key in. If you do not know the correct parameter, or miss a parameter because you simply dont know about it, then simulation results will not reflect actual situation. To factor for the unknowns, safety margins are added, like F-35 being certified for 8000 hours but testing to prove the airframe lasts 16,000 hours. Once it's successfully meets primary criteria, then excess margins can be shaved off.

I'll give you a practical example of getting parameters right. Soviet ships use 5 mm thickness plates because they operate in Northern Atlantic & Pacific waters where salinity is low and temperatures are low. British Royal Navy uses 8 mm thickness plates because they operate globally. INS Andaman, a Soviet Petya class corvette, was designed and built with 5 mm thickness plates. In Indian tropical waters, it corroded more requiring more refits. It received a temporary refit because Naval Dockyard Vishakhapatnam capacity was full refitting its sister ships. INS Andamans sank after the plating suffered failure. This accelerated corrosion effect of tropical waters was never known or foreseen. Today, based on that experience, INS Shivalik & INS Kamorta use 10 mm thick plates.

Its easy typing AR&DC should've used blah blah to get the landing gear meet impact load requirements while weighing as less as possible in the first iteration itself. However, very few get it right in the first iteration.

Same for control law testing and refining, as well as improving the Air Data Computers, that happened with LSP-3.

You can do just the design upto the LSP stage concurrently and you would have go the overwhelming bulk of it right and factored in manufacturability and maintenance.

Please amplify the bolded part as to how we would have got overwhelming bulk of it right when as per Dr. Tamilmani, the following tests remain

http://www.newindianexpress.com/nation/ ... 52712.html

The Tejas fighter will have to cross six milestones in the next 15 months, before the aircraft is given the final operational clearance (FOC).

The Russian-made 23 mm GSH gun is the next in line to be integrated to the aircraft. Capable of firing at 3,600 to 4,000 rpm, the integration of this gun is seen as a challenge considering the vibrations involved during action.

“Lots of surrounding LRUs need to be certified again for higher level of vibration. Ground firing or butt firing needs to be done initially before getting the gun onboard Tejas. The projectile speed of the gun is around 750 meter per second,” he said.

Suppose an LRU needs redesign, rebuild and re-testing if it fails to manage the vibrations, then how can you avoid it? How would you have got overwhelming bulk of it right?

There is the example of Marut canopy ejecting because gun vibrations cracked the bakelite switch that resulted in electrical contacts coming together and ejecting the canopy.

The Tejas will also increase the angle of attack from 22 to 24 degrees enabling the pilot to go for care-free manoeuvring.

Assuming control laws need enhancement to do this and require further testing, then how can you avoid it?

The braking system of Tejas will also need to be improved. “The heat capacity needs to be increased. Else we will have to put a better cooling mechanism for the brakes, similar to the fans in the MiGs,” Tamil Mani said.

This was not foreseen and requires re-development or an alternate solution of fans that may or may not work. How is the IAF at fault here? Or 1000's of orders would've prevented the brakes from overheating?

The nose cone radome of Tejas is another part that is expected to get a relook. “Now the radome is made of composite materials and we will change it to quartz. Today we are getting a radar range of 45-50 km and we need to improve the same to 80-plus km with the new material,” the official said

Again, the radome faced issues attenuating signals that resulted in significant losses. How could this be foreseen? I remember insinuations on this forum that IAF wanted unobtanium ranges, but surely 80 km range is a reasonable specification. And this is from Dr Tamilmani and the ADA team. And 10+ PV+LSP+SP aircraft have been built with sub-standard radomes while the quartz radome is being tested.

What I mean by dropping the ball is not getting fully involved when it went from TD to FSED stage. That is exactly where the IAF should have stepped in. I pointed out the weapon spec mismatch here, which required wing redesign and set the program back by 1 year.

Ah, I knew the weapon argument would come back. Yes, the R-73E required wing re-design but rest of aircraft development was progressing concurrently.

As well as mid air refuelling, following quote from Dr Tamilmani debunks any argument that it adds to development time.

Tejas will also have an air-to-air refuelling probe (Cobham, UK) in the FOC configuration. “We have started the integration work. Similar work was done on Jaguar and AEW&C (Airborne Early Warning and Control) platform. We have the expertise now,” Tamil Mani said

As for Litening, Derby, Griffin & Paveway, I've pointed out multiple times that development work from Elta 2032 + Derby on Sea Harrier, and Elta 2032 + Litening + Griffin + Paveway on Jaguar was reused.

You forget the Jaguar IM added Elta 2032 and US Harpoon in the same time. If adding radar and weapons was so complex, then how does HAL + IAF replace Thomson Agave radar with Elta 2032 and Sea Eagle with Harpoon on Jaguar IM and successfully test it in 2015?

http://www.hindustantimes.com/india/a-f ... hDRPN.html

The Indian Air Force launched an anti-ship Harpoon missile from a fighter plane for the first time at a pre-designated target in the Arabian Sea last week. The missile, built by US defence giant Boeing, was launched on May 22 from a Jaguar maritime strike fighter that flew 200 nautical miles off the west coast to carry out the mission, a source said.

The fighter belonged to the IAF’s maritime strike squadron based at the Lohegaon airbase outside Pune. The Jaguar was refuelled midair during the mission, the source added.

The development time of Tejas to achieve IOC is flight testing, not weapons. The development time to achieve FOC is things like AoA and brakes and gun vibration, and not Python, Derby or refuelling probe. Otherwise the Jaguar IM would've taken a much longer timeframe to integrate Harpoon and Embraer AEW&C to incorporate refuelling probe. Both are successfully flying.

As a side note, if ever they decide to integrate Harpoon with Tejas, it would be a quick fix.

And BTW, the Jaguar also added CBU-105 SFW http://www.ainonline.com/aviation-news/ ... as-jaguars

And will shortly add Elta 2052 http://ajaishukla.blogspot.in/2015/10/c ... s-air.html

Says HAL Chairman, T Suvarna Raju, “I was delighted when Elta offered the AESA radar for the Jaguar. Elta wanted neither development costs, nor more time.”

“Israeli Aircraft Industries (IAI is Elta’s parent company) and HAL have signed an agreement that says we would partner IAI in developing the improved AESA radar for the Tejas”, confirms Raju.

Defence ministry sources say the agreement specifies that 60 per cent of the new radar, by value, would be manufactured in India.

Its time to lay to rest the "IAF adding weapons leading to Tejas delays" BS when Jaguar weapons are multiplying like rabbits.

Let me also point out a few things more than Arup Raha Harrumphed about recently as "improvements "

Asked for provision of growth for AESA. Asked for higher fuel load and range, asked for airborne refuelling,asked for IR tracker, asked for internal SPJ (they had already done the Bison upgrade by then, they knew that an SPJ was needed), asked for higher thrust engine. IF they had done that at the start of FSED phase, the LCA that would have come out would have the mould line of the proposed MKII right from the beginning and NOT the current Mk1 version! There would have been a fuselage stretch for extra room for equipment and fuel, aero refinements to match that ask and you could have fielded a version with a normal radar like the MK1 but with an airframe that incorporated the stuff you wanted , you have got a right sized airframe and not come and Harrumph and try to derail the program at the last minute saying oh, I want an INTERNAL SPJ! Where the hell were you guys at FSED stage , when the plane is basically getting re-engineered?

Do you have a source for this? Because I've never read or heard higher fuel load, range, IR tracker in IOC, FOC & SOP 2018.

IRST was NEVER a requirement for Tejas nor is it NOW. Even the Su-30 uses Litening as FLIR instead of its OLS IRST because Litening has better resolution and range. Tejas will use the Litening. 164 Litening G4 were ordered.

The higher thrust is a Navy requirement, because NP-1 & 2 are too heavy to take off from an aircraft carrier with useful loads. IAF Mk1A will use the same old F-404IN20 engine.

As I quoted Dr. Tamilmani, mid air refueling was added because work was done on Mirage 2000, Jaguar, AEW&C (that was never designed for A2A refuelling by Embraer) and ADA was confident on being able to do it in a short timeframe.

Please give a source because this rant of yours is goes against published information.

...

...endless shifting of the goal post by clueless guys like Anup Raha...

Neshant - can you post a source where Raha shifted goalposts with higher fuel load and range and asked for IR tracker?

Otherwise you're just being a choir boy from the book Lord of the Flies adding vocal support to Vina's incorrect facts.

[nirav]

We seem to be on a repeat cycle. Must archive these posts into a sticky thread. Every few months, either its IAF bashing or HAL/ADA bashing with the same arguments and counter arguments.

On a LONG term basis, the LCA program has been an excellent one which has taught us many things and shown our strengths and weaknesses crystal clear.Theres no doubt in my mind that the lessons learned after decades of sweat and toil will be taken into consideration and another Marut story wont repeat.

It is disappointing that after having the LCA almost near FOC, we are found wanting in production capacity.
The LCA in its current avatar isnt just a MiG21 replacement as it was intended to be but a full blown L-MRCA.

Im guessing the F-16 line talks will have a keen focus on production rates.The americans are indeed masters of large scale engineering.The experience might end up being beneficial for future programs.

2 LCA lines @ 16 ac/year is a jingos dream, think it will remain just that cause of deficiencies in our industrial manufacturing strength.The pvt sector wont/cant step up to the ocassion and HAL can only do so much with available resources.

It saddens me no end that after toiling for so long, when we have the final product available, its entry into IAF will be restricted in numbers due to lack of manufacturing capacity.

There are somethings though that mango people like us will never know, wrt to the LCA program and the Arjun program.
Need to find a way to accept it and move on.

[saumitra_j]

There may have been consultants but TATA developed the engine along with parts suppliers. Even Mahindra and TAFE (simpsons) develop there own engines. It is not that India doesn't have capability to develop its own engine

Thanks Kakarat I stand corrected on state of affairs w.r.t. IC Engines, it not as bad as I had thought!

[nirav]

There may have been consultants but TATA developed the engine along with parts suppliers. Even Mahindra and TAFE (simpsons) develop there own engines. It is not that India doesn't have capability to develop its own engine

Thanks Kakarat I stand corrected on state of affairs w.r.t. IC Engines, it not as bad as I had thought!

while completely OT, IC engines and the capability of desi manufacturers is nothing short of a joke.

Bajaj and TVS being given as examples ! All they do is keep making single cylinder trash. Hero group !? had it not been for Honda the munjals would have had India move on their bicycles.
All they could do is come up with gimmicry, 2 spark plugs, 3 spark plugs in a cylinder !! And Hero group, stickers. And then some More stickers.

We are so so so far behind in the IC engine space, Honda has forgotten IC designs in the 70s which our desi manufacturers cant even come up with in 2016.

In light of the above, ISRO needs to be worshipped.Like literally.
Showing Tvs/Hero/Bajaj as IC engine manufacturers is plain ridiculous.!

[JayS]

Like it or not concurrent engineering is the future.

Models are chosen as per circumstances and even for Tejas, it was never a mutually exclusive either/or Waterfall/Concurrent model. There was concurrency wherein radar and engine development proceeded concurrently. Even different PV's and LSP's were tasked for different tests

I certainly never said Concurrent engineering != Iterations. You are making that distinction. Concurrent engineering simply means design iterations on various systems run parallel without waiting for one to finish before the other can start. Number of iterations may not be reduced but the time for entire project can be compressed. As time passes by the extent of concurrency will only go up. We have barely scratched the surface with Tejas.

My point was one cannot wait until everything is proven 100%. Calculated risks have to be taken. Because certain things take too long a time. And certain problems can only be seen when large scale deployment happens.

[vina]

while completely OT, IC engines and the capability of desi manufacturers is nothing short of a joke.

Bajaj and TVS being given as examples ! All they do is keep making single cylinder trash. Hero group !? had it not been for Honda the munjals would have had India move on their bicycles.
All they could do is come up with gimmicry, 2 spark plugs, 3 spark plugs in a cylinder !! And Hero group, stickers. And then some More stickers.

We are so so so far behind in the IC engine space, Honda has forgotten IC designs in the 70s which our desi manufacturers cant even come up with in 2016.


Showing Tvs/Hero/Bajaj as IC engine manufacturers is plain ridiculous.!

This is plainly ignorant. They make single cylinders because that is ALL you as a country can afford to buy in huge volumes. They KNOW their customers, you dont know it. And let me guess , the bike you are riding is NOT a 4 cylinder inline Honda/Suzuki/Yahama /Kawasaki superbike or an Italian one like Ducati/Aprilia, but rather a humble single cylinder commuter one, or at best a 200 odd cc one. . They are mass market bike makers and not a ultra niche superbike maker. And yes. Compare what they are offering at that price point with the equivalent of what Honda/Yahama/Suzuki offer, they are pretty good. The equivalent capacity Honda or others offer anywhere in the world arent very differnent, unless you claim that Honda in the 1970s was offering exaclty same engines worldwide that they are offering today! (and easy to debunk. Many Bajaj/TVS models have fuel injection which the Hondas in the 70s didnt have . All the models have electronic injection. which the Honda 70s models didn't have. In fact, I would bet that EVERY local bike today has a far higher specific power and specific torque than a Honda in the 70s.. and in fact will be comparable to what the big 4 Japanese bike TODAY has..

I will bin this post along with that other ignorant one from SaumitraJ who shot his mouth off about "We dont produce a SINGLE IC engine" while in fact there are literally dozens over the past 30 years.

In light of the above, ISRO needs to be worshipped.Like literally.

For what ? Making a 1960s vintage French liquid engine that was acquired via tech transfer ? Or making solid engines that are the simplest to make ? For building a cryogenic engine that the Russians gave the blueprints and hand holding for , all this with a huge Govt R&D and budget and institutional support and lack of competition and pressure on timeline and bottomlines?

[vina]

Thanks Kakarat I stand corrected on state of affairs w.r.t. IC Engines, it not as bad as I had thought!

Contrary to your pre conceived notions, the private sector many areas in their market segments are PRETTY good and in fact faced global competition successfully, stared it down, and indeed are globally competitive. Two wheelers,auto ancillaries, autos, chemicals, generic pharma, engineering design and services and a whole host of areas. Like I said, the big failure has been the Govt sector (both civil and defence) for mainly structural reasons and also other reasons. So don't project your ignorance, inadequacies and sneering condescension on things you have idea about (classic example Nirav's post after yours.. I seriously doubt he would be able to afford a Ducati and even if he could , if it would be suitable for Indian conditions, and claim a Ducati is "better", when both are not in the same segmen.. Sort of like comparing a Honda Jazz to a Ferrari California and saying that the Jazz has only 4 cylinders and Honda has made only 4 cylinder and 6 cylinder trash and never an 8 or 12 cylinder engine.. i will leave out racing here.).

[nirav]

^ lol.
Your guess is as bad as your 6ton to GTO spreadsheet rocket.

I ride a Kawasaki Ninja 300, parallel twin

Fact is, India's market is way too big as is evident by the litre class sales. heck take a look at ktm duke390/RC 390 sales.

TVS, Hero and Bajaj can only engineer trash single cylinder mills. For even a bigger single cylinder mill Bajaj ran to KTM.

It's beyond their capacity, building a engine which adorned the CBR 400 rr which btw is long out of production.

Hence 2,3 spark plugs in a single cylinder hogwash, rather than some real engineering..

[shaun]

^^^^ +1 the JV's of the 80's still running the show.

[vina]

Ok. Back to regular programming and no more auto industry "I think" nonsense please. Clearly many here shooting their mouth off have zero engineering /product or even a business background .. No more on that.

There was concurrency wherein radar and engine development proceeded concurrently. Even different PV's and LSP's were tasked for different tests http://www.tejas.gov.in/history/milestones.html

PV-3 ..........
PV-2 and PV-3 ..... (PV-1)...........etc

Again let me repeat . You are mixing up to vastly different things. Concurrent Engineering is NOT paralleling certain tasks like you would using PERT/ CPM kind of project planning, where you decide which tasks are critical, which need to be in parallel, how many resources, test beds etc needed. You are confusing project planning with a product methodology . I repeat again, we are talking about different things here.

There is a very practical problem with simulation. Simulation is as good as the parameters you key in. If you do not know the correct parameter, or miss a parameter because you simply dont know about it, then simulation results will not reflect actual situation. To factor for the unknowns, safety margins are added, like F-35 being certified for 8000 hours but testing to prove the airframe lasts 16,000 hours. Once it's successfully meets primary criteria, then excess margins can be shaved off.

I'll give you a practical example of getting parameters right. Soviet ships use 5 mm thickness plates because they operate in Northern Atlantic & Pacific waters where salinity is low and temperatures are low. British Royal Navy uses 8 mm thickness plates because they operate globally. INS Andaman, a Soviet Petya class corvette, was designed and built with 5 mm thickness plates. In Indian tropical waters, it corroded more requiring more refits. It received a temporary refit because Naval Dockyard Vishakhapatnam capacity was full refitting its sister ships. INS Andamans sank after the plating suffered failure. This accelerated corrosion effect of tropical waters was never known or foreseen. Today, based on that experience, INS Shivalik & INS Kamorta use 10 mm thick plates.

Classic example that shows we are talking about different things. .. Okay. we chose plate of thickness X mm in the design. In the traditional method we would throw it over the wall for the manufacturer to make it and then he in turn will throw it over the wall for maintenance to take care of. Concurrent engineering would be things like , in the review meeting while the drawings are made, the manufacturing guy would say, that my press is only X tons, I cant curve a plate of > Y mm by more than that radius, so dont do it that way, the maintenance guy would say, let he seam come here, so that if the plate needs to be changed, I can cut with this kind of torch easily here and do this... and they ask how many seams of what specs are needed and they plan the welding consumables and the Xray NDT testing for verifcation of the welds .. . Notice, this does not depend on whether you chose a 5 mm plate or an 8 mm plate . It is just that, it will help you design intelligently and make it well and efficiently with least trouble and minimal effort. If you later find that you need to redesign with a 10 mm plate, you still do the same process and get similar efficient results.

Please amplify the bolded part as to how we would have got overwhelming bulk of it right when as per

Read he above lines.

Ah, I knew the weapon argument would come back. Yes, the R-73E required wing re-design but rest of aircraft development was progressing concurrently.

As well as mid air refuelling, following quote from Dr Tamilmani debunks any argument that it adds to development time.

Well, this 1 year delay due to aeroelastic issues because of different weapon specs was "proven" only when I postulated that as a cause here and a former structural engg of ADA who was active in this board confirmed it so. Othewise it too would have been conveniently "buried" and "debunked"

Tejas will also have an air-to-air refuelling probe (Cobham, UK) in the FOC configuration. “We have started the integration work. Similar work was done on Jaguar and AEW&C (Airborne Early Warning and Control) platform. We have the expertise now,” Tamil Mani said

Jaguar always had the plumbing in the original versions. The IAF just had to put it back in. Fact is, if it was designed in, right from the beginning, putting it in is far easier than squeezing in one for which a design allowance already hadnt been made.

The development time of Tejas to achieve IOC is flight testing, not weapons.

Sorry . The bulk of the delay (per the CAG reports) was due to the lack of Plan B for the failed radar to be developed by HAL. The decision making to finally go the Elta 2032 way was a tortured one. The reason why you can put any radar and weapons on a platform like Jaguar and LCA is because they are standards based (MIl 1553 std), which you cant do with the Mig 29 and 27 in the ordinary course and need to go to the Russians for a rip and replace upgrade. In fact I would say the nearly 2 year effort of integrating a legacy R 73 to the LCA when the Russians wouldnt cooperate and open the protocol out was a total waste.

It would have required painstaking work with a protocol analyser and you would have at best limited integration and possibly not the full seamless one with DASH helmet etc, unless it is Mil Std 1553b compliant R73 (which the Russians sell as well). Finally wisdom dawned and they went with the Israeli package of Python V and Derby ER. The delayed decision making in radar and weapons was the key reason for delays . This is available in CAG reports and

The development time to achieve FOC is things like AoA and brakes and gun vibration, and not Python, Derby or refuelling probe. Otherwise the Jaguar IM would've taken a much longer timeframe to integrate Harpoon and Embraer AEW&C to incorporate refuelling probe. Both are successfully flying

Please read what I wrote about Mil Stds bus on why Jag/Embraer/Harpoon Python/Derby and also look up the trouble they had with modernising the Mig 27 and the effort that went into it.

As a side note, if ever they decide to integrate Harpoon with Tejas, it would be a quick fix.

And now you will know why (infact I think even the SU 30 use a Mil Std 1553 bus.. you can do it on the su 30 as well easily).

Do you have a source for this? Because I've never read or heard higher fuel load, range, IR tracker in IOC, FOC & SOP 2018.

But you heard that they have asked for the Gripen E and the F16 and sent RFPs. What do they bring to the table other than these in tersm of capabilities?

IRST was NEVER a requirement for Tejas nor is it NOW. Even the Su-30 uses Litening as FLIR instead of its OLS IRST because Litening has better resolution and range. Tejas will use the Litening. 164 Litening G4 were ordered.

While the FLIR can be used in a2a , the ols and it's western analogs are the ones used in a2a and does away with the need to carry an IRST pod always, even if you are in a pure air defense role.

As I quoted Dr. Tamilmani, mid air refueling was added because work was done on Mirage 2000, Jaguar, AEW&C (that was never designed for A2A refuelling by Embraer) and ADA was confident on being able to do it in a short timeframe.

Already replied about having it designed in, vs squeezing in something later. Jag an M2k were already plumbed for mid air refueling. AEW&C is anyways a custom modification from the stock airframe. Not too difficult to add that into such a large airframe. Totally different case with the Tejas.

[nirav]

Aand some one furiously harrumphed and back peddled.

[shiv]

Why doesn't this happen in India?
http://www.popularmechanics.com/technol ... that-work/

My guess is that the number of inspired and technically adept people in India is miniscule, apart from being theory masters in general

[vina]

^ lol.

I ride a Kawasaki Ninja 300, parallel twin

Pah.. That is what is called a "Crotch Rocket" .A sorry excuse and a me too of a bike. Get yourself a real bike if you want to talk about one.

For even a bigger single cylinder mill Bajaj ran to KTM.

Why not ? They OWN KTM and in fact the KTM 200 and the Pulsar 200 NS use many common parts and the engine cylinder is same (okay the Duke has fuel injection and DOHC, while the Puslar has a SOHC head and carbs. you need that for product differentiation and to justify the price difference)

It's beyond their capacity, building a engine which adorned the CBR 400 rr which btw is long out of production.

And pray who will buy one even if they make one! Clearly Bajaj is not foolish and they run a business ? They dont have the brand and they have KTM to offer those !

[nirav]

The whole point was desi engineering and capacity to develop an IC engine.not which bike is better or companies' profitability..

I'd be more than willing to discuss this in the auto thread ..

[NachiketM]

http://idrw.org/why-india-might-be-plan ... mb-trucks/
This does make sense ...

[SaiK]

^but fails to call spade a spade in clear terms. shiv ji, that is exactly the question we were asking 20 years ago. we haven't change our questions even in Modi era.

*********billions of blue blistering barnacles*************

[Indranil]

MODERATOR NOTE: No more discussion of IC engines, motorbikes on this thread.

[Gyan]

As per my googling:-

F-16 Empty weight 9700kg, CFT 300kg, internal fuel 2600kg and CFT fuel 1300kg. Engine 145kn.

LCA Empty weight 6500kg, internal fuel 2500kg. Engine 85kn.

So LCA range should be same as F-16 with CFT?

[ramana]

Indranil, I second a ban for a few posters in this thread. Plain warning is not working.

[RKumar]

Tsarkar ji ... you are respected and senior member of BRF. But I dont agree with your arguments ... if there is will in IAF, there are many ways. Not a single way.

There are many examples where IAF inducted planes which were not even inducted in their own country. So IAF did dirty their hands to fix issues. Even today, no inducted plane is trouble free.

Regarding,
Breaking - they could have deployed it in plains there runway is not an issue. Lets say, it take double the normal stop distance.
Radar - we could have deployed them with mother fighter aka Su-30 or early warning assets. While we have final solution in work. It has demostrated excellent hitting capability in air-2-ground in live IAF excercise.
Gun - land based validation is done. Again, could use it for ground targets. I doubt, today anyone will get a chance to do much dog fighting when having 80-300km detection range.
AoA - It is already touched the magical number 25.

Now adding some of the features, which all other fighter dont have (some might have)
- can take off from leh with good load
- hot as well as pressure fueling
- good sortie rate
- locally produced product
- can add new features on demand with iterations

IAF pilots are loving it since last 5 years at least. Which air force devalue their national product? Even Pakistani air force with J-17 - which has half the LCA capabilties, has all praise for it. Or China with J-11, have lots of crashes but will still project it as good. I dont want IAF to be a copy of these air forces but at least better then declaring LCA as three leg cheeta on IOC event. It displays, how much support we have got for LCA in IAF decision making circles.

Selecting and fighting for Hawk and Rafael, till tooth and nail are examples. Now with this great poly of imported single engine fighter - Make in India is a cruel joke on dead body of home grown n killed LCA.

[Indranil]

^^^ Correction, LCA has been flown till 26, cleared till 24. It is in the process of being cleared till 26.

[rohiths]

As per my googling:-

F-16 Empty weight 9700kg, CFT 300kg, internal fuel 2600kg and CFT fuel 1300kg. Engine 145kn.

LCA Empty weight 6500kg, internal fuel 2500kg. Engine 85kn.

So LCA range should be same as F-16 with CFT?

Just to summarize the key advantages of LCA over F-16
1. Radar Cross Section: LCA has a RCS of ~0.5sq m vs F-16 of ~2sq m. This reduces the detection range by 50%. It will invariably be the first aircraft to fire a BVRAAM and will have significant advantage in Air to Air combat
2. Range: LCAs range should be greater than F-16 for the same mission profile given that it has similar internal fuel and lower weight & fuel consumption
3. Cost: The per unit cost of F-16 will atleast be $100 million vs LCA cost of $25 million. We will get 4LCAs for every F16. The operating cost per hour will be lower given that it is a lighter plane
4. Turnaround time: The turnaround time of LCA is faster and should result in more sorties per day than F-16

So for a given amount of spending we would get 4X more LCAs than F-16. Each LCA can do ~1.5X more sorties than F-16 which means the effective sortie rate would be 6X more than F-16. Against a country like Pakistan, generating a high sortie rate in the beginning of the war would give overwhelming advantage.

[Pratyush]

^^^ Correction, LCA has been flown till 26, cleared till 24. It is in the process of being cleared till 26.

I seem to be missing the point to the discussion what is the significance of 26 & 24.

[Rakesh]

Pratyush: When Indranil Saar talks about 26 and 24, he is referring to the degrees of angles of attack....

https://en.wikipedia.org/wiki/Angle_of_attack

[shiv]

^^^ Correction, LCA has been flown till 26, cleared till 24. It is in the process of being cleared till 26.

I seem to be missing the point to the discussion what is the significance of 26 & 24.

This is what I think it means.

The LCA can fly at 26 deg AoA. The test pilots have done it. But to "clear" it that 26 deg will have to be tested under all sorts of flying conditions and the control laws written into the software so that no matter what the pilot does at 26 deg AoA he will not enter into an unsafe regime. I suspect this has already been done up to 24 deg.

[vina]

This is what I think it means.

The LCA can fly at 26 deg AoA. The test pilots have done it. But to "clear" it that 26 deg will have to be tested under all sorts of flying conditions and the control laws written into the software so that no matter what the pilot does at 26 deg AoA he will not enter into an unsafe regime. I suspect this has already been done up to 24 deg.

The pilot in the LCA cannot push the plane beyond what the FCS limits him. If the FCS limit is set at 24 deg, that is all he can do. To get to 26 deg, the control law team has to clear it and then reset the limit to 26 deg and the pilot will be able to pull it. If the pilot pulled 26 deg, he did so only after the limits were enhanced by the control team.

Anyways there is another thing I am scared to put up here, because if some IAF brouchure reading types come across it, it will mean another change in the current MK1 !

That has to do with how the actuators work. Back in the old days, there pilot's manipulated the flying surfaces that were connected by cables that connected to the controls. So obviously the amount of force avaialble to move it is limited by the muscle power of the pilot. Soon those limits were exceeded and hence Hydraulically boosted control surfaces came about. The pilot pulled the same controls and the same cables, instead of connecting directly to the flying surface, opened valve that in turn activated a hydraulic actuator that moved the surface. Now when FBW came about, instead of a cable, an electrical signal from the flight computer opened and closed valves in the hydraulic actuator.

All this works fine. However the downside is, it is an energy drain (since the hydraulic system has to kept pressurised all the time) and since it is a flight critical part, you will need redundancy, hence two hydraulic circuits (pipes, reservoir, pumps etc.etc..) . The current state of art is "all electric systems" . What it means is that there is an electric stepper motor and the hydraulic actuator etc packed as as single unit. There will be two wires leading in to the package for redundancy and both power and signal come through the wire. This system is self contained and gets charged just when required. Also what it means is that you don't need the hydraulics anymore (leak prone, heavy ) and the overall reliability increases along with significant weight savings.

What ADA can do is approach Until /Oierope and get commercially available Electro Hydraulic Actuator instead of the legacy Moog ones they use now and do an easy upgrade and get rid of all the hydraulics etc. Will make life much simpler, liberate space, make internal arrangement less complex and will also reduce weight (by around 300 Kg or so in a LCA sized aircraft) . This can be done for Mk1A , when the are doing internal rearragment and stuff and also putting in the AESA. That way, any maintainability whines about the hydraulics and access concerns will be gone as well. This is an easy low risk way of getting some weight savings, and increasing reliability and also simplifying layout and maintenance.

[vina]

A380 More Electric Aircraft

For years engineers have dreamed of an all-electric aircraft. They have envisioned a concept called "power-by-wire," in which electrical power moves aircraft flight surfaces. Gone would be the complex, heavy, maintenance-intensive, and (in combat) vulnerable hydraulic systems with their flammable liquids operating at high temperature and pressure. Gone, too, would be the miles of tubing, the pumps and valves. Weight could be shifted from plumbing to passengers, fuel or mission payloads.
The transition to an all-electric aircraft is still many years in the future. But aircraft engineers have tested electrohydrostatic actuators (EHAs), which combine electrical and hydraulic power: hence the evolutionary "more electric aircraft" idea. EHAs are electrically powered but use small hydraulic pumps and reservoirs that transform electrical power into hydraulic power. Airbus has worked with EHA flight control technologies for more than a decade. A320 and A340 flight test beds have operated since 1993-94 and 2000, respectively. The U.S. military’s Joint Strike Fighter and C-141 Electric Starlifter programs have tested EHA systems, as well.

[Rammpal]

What ADA can do is approach Until /Oierope and get commercially available Electro Hydraulic Actuator instead of the legacy Moog ones they use now and do an easy upgrade and get rid of all the hydraulics etc. Will make life much simpler, liberate space, make internal arrangement less complex and will also reduce weight (by around 300 Kg or so in a LCA sized aircraft) . This can be done for Mk1A , when the are doing internal rearragment and stuff and also putting in the AESA. That way, any maintainability whines about the hydraulics and access concerns will be gone as well. This is an easy low risk way of getting some weight savings, and increasing reliability and also simplifying layout and maintenance.

What's stopping them from using full electric actuators, i.e.: linear motor

[JayS]

As per my googling:-

F-16 Empty weight 9700kg, CFT 300kg, internal fuel 2600kg and CFT fuel 1300kg. Engine 145kn.

LCA Empty weight 6500kg, internal fuel 2500kg. Engine 85kn.

So LCA range should be same as F-16 with CFT?

Just to summarize the key advantages of LCA over F-16
1. Radar Cross Section: LCA has a RCS of ~0.5sq m vs F-16 of ~2sq m. This reduces the detection range by 50%. It will invariably be the first aircraft to fire a BVRAAM and will have significant advantage in Air to Air combat
2. Range: LCAs range should be greater than F-16 for the same mission profile given that it has similar internal fuel and lower weight & fuel consumption
3. Cost: The per unit cost of F-16 will atleast be $100 million vs LCA cost of $25 million. We will get 4LCAs for every F16. The operating cost per hour will be lower given that it is a lighter plane
4. Turnaround time: The turnaround time of LCA is faster and should result in more sorties per day than F-16

So for a given amount of spending we would get 4X more LCAs than F-16. Each LCA can do ~1.5X more sorties than F-16 which means the effective sortie rate would be 6X more than F-16. Against a country like Pakistan, generating a high sortie rate in the beginning of the war would give overwhelming advantage.

This kind of exaggeration does not help the cause. You should re-check the numbers.

[JayS]

Anyways there is another thing I am scared to put up here, because if some IAF brouchure reading types come across it, it will mean another change in the current MK1 !

What ADA can do is approach Until /Oierope and get commercially available Electro Hydraulic Actuator instead of the legacy Moog ones they use now and do an easy upgrade and get rid of all the hydraulics etc. Will make life much simpler, liberate space, make internal arrangement less complex and will also reduce weight (by around 300 Kg or so in a LCA sized aircraft) . This can be done for Mk1A , when the are doing internal rearragment and stuff and also putting in the AESA. That way, any maintainability whines about the hydraulics and access concerns will be gone as well. This is an easy low risk way of getting some weight savings, and increasing reliability and also simplifying layout and maintenance.

These actuators are around since 1990s. I am sure IAF brochure reading types have picked it up by now through F35 brochure. So you don't have to feel guilty about giving ideas to IAF brochuritis patients. As such I mentioned them aleady in some post of mine somewhere on BRF.

nitpicking -Its Electro-Hydrostatic Actuators that you are referring to. Electro Hydraulic Actuators are the conventional types with external hydraulic power, only controlled via electronic control.

This is really "More Electric" i would say. In "All Electric" I would expect total elimination of hydraulic part altogether and stepper motors directly driving the control surfaces.