AMCA - Advanced Medium Combat Aircraft (HAL)

[aerokan]

You mean the softwares will cater for manufacturing defects, maintenance defects and bird poop? No.

Let me ask a few questions out of ignorance.

While doing RCS measurements in the measuring chambers, do they take bird poop and add it on the wings and measure it?

So does measuring a plane's RCS with bird poop make a difference in design like a poop-camouflage/poop-resistant paint/self-cleaning auto poop-ejector wings or similar design?

Does bird poop adds only RCS to AMCA/LCA while not adding to F-22/F-35?

Too many questions in my mind and too little poop to experiment with. I need more birds!!

 

[Twinblade]

As a matter of fact the concept of stealth itself is a flaw. There are experiments that has proved the so called RAS/RAM does not absorb radiation in the UHF band. This UHF counter stealth measures are still in development stage. A PhD thesis on this also exists from NAVAL POSTGRADUATE SCHOOL MONTEREY, CALIFORNIA.

Just wait for FSS based multilayer metamaterial rams to get cheaper. Each layer of the composite would be printed with micro electrical resonator circuits like it is done on printed circuit boards, resulting in a composite panel with wideband radar absorbing properties, including UHF and beyond.

 

[dvdiyen]

Just wait for FSS based multilayer metamaterial rams to get cheaper. Each layer of the composite would be printed with micro electrical resonator circuits like it is done on printed circuit boards, resulting in a composite panel with wideband radar absorbing properties, including UHF and beyond.

Someone needs to develop a UWB FSS structure which is multilayered, should be very thin, and still allow radiations from VHF,UHF, S band, L-band,X-band and Ku band frequencies used in avionics.

 

[p2prada]

Let me ask a few questions out of ignorance.

While doing RCS measurements in the measuring chambers, do they take bird poop and add it on the wings and measure it?

Yup, but not literally. They have other replacements.

So does measuring a plane's RCS with bird poop make a difference in design like a poop-camouflage/poop-resistant paint/self-cleaning auto poop-ejector wings or similar design?

To see if even with bird poop in it, the aircraft can still retain its stealthy properties.

Does bird poop adds only RCS to AMCA/LCA while not adding to F-22/F-35?

Your sarcasm only comes out of your ignorance.

Too many questions in my mind and too little poop to experiment with. I need more birds!!

You should start collecting, then.

 

[rvjpheonix]

Let me ask a few questions out of ignorance.

While doing RCS measurements in the measuring chambers, do they take bird poop and add it on the wings and measure it?

So does measuring a plane's RCS with bird poop make a difference in design like a poop-camouflage/poop-resistant paint/self-cleaning auto poop-ejector wings or similar design?

Does bird poop adds only RCS to AMCA/LCA while not adding to F-22/F-35?

Too many questions in my mind and too little poop to experiment with. I need more birds!!

OT
I had a bad exam today but this made my day!

 

[rvjpheonix]

This is a project of national importance. This project will put us on par with most of the world.There have been multiple iterations of this aircraft already, which is supposed to be a stealth aircraft. So definitely they must have undertaken tests for RCS measurements of the past models, including in anechoic chambers. there is far too much at stake for just going around and saying this design should be more stealthy than the other one. I don't expect everything to be made public considering the PR management of our PSU's. Because something is not available for everyone to see on open sites does not mean it does not exist. As for manufacturing problems and bird poop did you see the number of rivets and not so stealthy elements on pak fa? Doesn't mean that they wont be ironed out. What I mean to say is that these wont be important things to be seen during the design phase. The manufacturing process can be refined later on to provide better stealth.

 

[p2prada]

This is a project of national importance. This project will put us on par with most of the world.There have been multiple iterations of this aircraft already, which is supposed to be a stealth aircraft. So definitely they must have undertaken tests for RCS measurements of the past models, including in anechoic chambers. there is far too much at stake for just going around and saying this design should be more stealthy than the other one. I don't expect everything to be made public considering the PR management of our PSU's. Because something is not available for everyone to see on open sites does not mean it does not exist. As for manufacturing problems and bird poop did you see the number of rivets and not so stealthy elements on pak fa? Doesn't mean that they wont be ironed out. What I mean to say is that these wont be important things to be seen during the design phase. The manufacturing process can be refined later on to provide better stealth.

We have no anechoic chambers. We have no RCS measurement sites. They are being built today. Before the AMCA flies, it will take 6 years of ground work. That's what is happening today, most of it is on hold too.

Have you seen the number of rivets on F-22 and F-35 too?

You can't "refine" the manufacturing process to make a bird more stealthy. You design the bird to be stealthy from the get-go. You refine the manufacturing process to only make it less complicated, more efficient and faster.

Another severe case of talking too much and knowing nothing.

 

[aerokan]

To see if even with bird poop in it, the aircraft can still retain its stealthy properties.

Are there any stealth aircrafts in the world currently which can currently retain their stealth even after extra irregular particle addition or dents or that irregular RAM paint job?

If yes.. that's a great design and we should all aspire to get to that stage. If not, how would measuring that RCS help if one can only 'design' a stealth aircraft but not improvise much. Or does every plane goes through the RCS chamber everytime they had repairs or a paint job or for some other reason?

Your sarcasm only comes out of your ignorance.

200% agreed. It's hard to resist the natural urge to respond to some situations. But that still doesn't get me the answer.

 

[Twinblade]

The largest anechoic facilities as they exist today in India
CABS:- 35 x 18 x 18 meters used for testing AEWC&S antenna and other EM emissions. This is the newest facility and has come up only last year or so.
LRDE:- 20 x 16 x 6 meters, used for EMI/EMC testing of radars, Tejas and Arjun subsystems. If Tejas prototypes have been tested for RCS inside anechoic chamber, then it has been tested most probably at this facility, however that is unlikely as it has testing facilities for Mi-std-461E which pertains to EM emissions and interference and chambers designed for EMI/EMC are slightly different than the ones used for RCS.
NAL:- 10.5 x 7.3 x 3.1 meters, the only facility that offers measurement of RCS for aircrafts as of today.
There is a large anechoic chamber coming up at VRDE for EMP testing of armoured vehicles.

 

[Twinblade]

Or does every plane goes through the RCS chamber everytime they had repairs or a paint job or for some other reason?

Not a full RCS testing but expensive repairs and significant amount of testing is required for stealth aircraft. The biggest advantage of F-35 that is being advertised is field repair capability of the panels without degrading the RCS.

 

[Decklander]

The largest anechoic facilities as they exist today in India
CABS:- 35 x 18 x 18 meters used for testing AEWC&S antenna and other EM emissions. This is the newest facility and has come up only last year or so.
LRDE:- 20 x 16 x 6 meters, used for EMI/EMC testing of radars, Tejas and Arjun subsystems. If Tejas prototypes have been tested for RCS inside anechoic chamber, then it has been tested most probably at this facility, however that is unlikely as it has testing facilities for Mi-std-461E which pertains to EM emissions and interference and chambers designed for EMI/EMC are slightly different than the ones used for RCS.
NAL:- 10.5 x 7.3 x 3.1 meters, the only facility that offers measurement of RCS for aircrafts as of today.
There is a large anechoic chamber coming up at VRDE for EMP testing of armoured vehicles.

I had told you that NAL does only scaled model testing for ac RCS.

 

[Twinblade]

I had told you that NAL does only scaled model testing for ac RCS.

You probably confused me with someone else, I was saying the same thing

 

[ersakthivel]

There is no point in that. Rough RCS is not true RCS. There is a heaven and sea difference between the two.

It is the "micro" areas that give away everything. Sure, your wing may have the perfect stealthy design, but that ding the maintenance crew decided to leave behind because one guy was careless with his spanner will kill the aircraft's stealthy properties. That little aberration in your paint job will increase your RCS by many times.

The macro areas will be all right, like nose, wing, tail etc, but without a full scale aircraft being tested in real world conditions where the aircraft is subjected to dust, ice and bird grime settling on your canopy, intakes etc, it is pointless to talk about RCS measurements on a model.

As a matter of fact, the macro issues of RCS will be taken care of during the design stage itself. Even the biggest experts on the planet cannot measure RCS by eyeballing the aircraft, but they know whether an aircraft is designed with stealth in mind or not. LCA, for one, was never designed with stealth in mind, neither was Su-27, F-15, F-16, Mirage-2000, EF-2000, Rafale or Gripen. They can, "maybe," reduce RCS by a certain degree, perhaps decrease detection range by half or more compared to a F-16/Mirage-2000, but that's not what's considered "stealthy."

"Rough " RCS that is got by software simulations s not true RCS ,

and

true low RCS fighters lwith RCS as low as 0.1 to 0.3 like Tejas can not be built without ," huge anechoic chambers " that existed in the west from the seventies is

your claim.

Now if this is true then

1. The Huge Anechoic chambers were built in 1970s.

2. The equations for stealth were known in 1970 itself and they were published open technical papers , no top secret stuff.

Then why did the low RCS fighters have to wait till the 1990s to make their debut.

let me give you the answer , only high computing power can build a complex simulation model which can stay true to the stealth equation and aerodynamic needs of the modern fighter.

So only after the advents of high powered computing low RCS fighters can be built.

And FEM based aerodynamic testing and codes that validate the low RCS shape model design can never go wrong.Because it is not a sales pitch like simulation where one fighter can kill all the AWACS and fighters of another side!!!!!!.

These are simulation models which are built on high end computing power that govern the behavior of the radar waves and shape of the low RCS model won't go wrong.

So at best anechoic chambers will help to validate and tweak the shape to some extent.

Without high end computing power based software simulation one can have stealth equation and huge anechoic chambers like a monkey rolling a couple of coconuts on both it's hands. But there is no use.

First of all to build a model you need a software simulation that stays loyal to aerodynamic needs and conform to stealth equations.Even If you sit cross legged in a huge anechoic chambers for months you won't get a model to test in the first place.

it is not surprising coming from a person who once stated that the complex , software for Canadian stock exchange which was implemented for the first time in the world ,built by TCS which makes millions of transactions worth billions of dollars every second is less demanding than the simple fly by wire software built for modern day fighters.

So even if they hang a Sukhoi- 30 in a huge anechioc chamber for ten years , keep tuning it using all the technicians in the world it's RCS will never reach the level of Tejas, because while Tejas used the highend computing software based simulations to arrive at it's low RCS air frame as a design goal, the Sukhoi team did not aim for it is the answer.

So low RCS of Tejas was not a fluke or stroke of luck delivered from divine sources as you ignorantly parrot here.

So even if SAAB hangs Grippen in anechoic chambers for decades the eight corner reflections from the two boxy rectangular air intakes located at the front and the extra RCS reflections from the two canard planes besides the two wing planes can only be fine tuned to certain extent , can never be eliminated.

I don't know why you can not stop this disgusting habit of ranting on tejas at any thread forever with not an iota of technical knowledge!!!!!!!!!!!!!!!

To avoid getting trapped in a stinging reply use the tactic being perfected by another poster here who while supplying a lot of technical info to slyly disgrace tejas the same way as you do , always keeps a door open to escape when cornered.

 

[lookieloo]

Not a full RCS testing but expensive repairs and significant amount of testing is required for stealth aircraft. The biggest advantage of F-35 that is being advertised is field repair capability of the panels without degrading the RCS.

That still depends on the situation. Here's an example from another board by someone else.

We received a F/A-18F that sustained damage from ground equipment bumping into the jet, and after basic repair, the RCS increased significantly enough when that section of the aircraft was angled towards the radar. The difference in alignment was relatively small (less than 1/8") [that's around 3 mm for you guys], but enough to keep the jet restricted to flight testing / training until the depot visit and skin servicing. The proper panel set was a composite material that is hard to repair away from depot. To fully repair the jet, would have pushed the total cost of repair to $1m+ (Class A), but doing it at depot phase inspection was less expensive.

 

[p2prada]

Are there any stealth aircrafts in the world currently which can currently retain their stealth even after extra irregular particle addition or dents or that irregular RAM paint job?

If yes.. that's a great design and we should all aspire to get to that stage. If not, how would measuring that RCS help if one can only 'design' a stealth aircraft but not improvise much. Or does every plane goes through the RCS chamber everytime they had repairs or a paint job or for some other reason?

The answer is we don't know. Even 50 years down the line we won't know.

Anyway I was talking about design stage, not after it is operational.

There is a reason why even old aircraft go through cold and hot tests. Similarly there is a reason why the aircraft goes through a lot of procedures for RCS measurement too. None of these are possible without a full scale RCS measurement facility. Even cars go through this, but for acoustics.

Post 1074 has more answers.

 

[lookieloo]

...does every plane goes through the RCS chamber everytime they had repairs or a paint job or for some other reason?

It's not a chamber in the case of repairs. Pictures of the equipment used aren't forthcoming, but my understanding is that Repair Verification Radar (RVR) test sets aren't exactly small/portable.

 

[rvjpheonix]

We have no anechoic chambers. We have no RCS measurement sites. They are being built today. Before the AMCA flies, it will take 6 years of ground work. That's what is happening today, most of it is on hold too.

Have you seen the number of rivets on F-22 and F-35 too?

You can't "refine" the manufacturing process to make a bird more stealthy. You design the bird to be stealthy from the get-go. You refine the manufacturing process to only make it less complicated, more efficient and faster.

Another severe case of talking too much and knowing nothing.

Hey, I just told my view which is based on common logic not hard facts. Maybe you are right.But I expect the scientists of my country to have enough knowledge and sense for getting all the facilities ready before making multiple iterations . But explain something ,how are they coming up with new models of a stealth bird in every aero india? You mean they are not tested for rcs? I dont think they will be just use the software alone for a multi billion $ stealth project. Are you definite that there cannot be any facility not known to the outside world.?After all, details of such projects are classified during initial years at least. There were reports of it being shelved and there was not much of a response from DRDO or ADA.

 

[p2prada]

Hey, I just told my view which is based on common logic not hard facts. Maybe you are right.But I expect the scientists of my country to have enough knowledge and sense for getting all the facilities ready before making multiple iterations . But explain something ,how are they coming up with new models of a stealth bird in every aero india? You mean they are not tested for rcs? I dont think they will be just use the software alone for a multi billion $ stealth project. Are you definite that there cannot be any facility not known to the outside world.?After all, details of such projects are classified during initial years at least. There were reports of it being shelved and there was not much of a response from DRDO or ADA.

Iran came out with shiny stealthy models too. What makes you think they have RCS measurement chambers? The designs we came up with are only models, not flying aircraft. Wait for a flying aircraft first. We have some level of facilities for models.

No, our scientists do not wait for technology before commencement of the project. They build infrastructure and develop technology after the project starts. That's why LCA has taken 30+ years. Half that time was taken for researching and building new technology.

DRDO/HAL/NAL will let us know when they have such a facility. We do have such facilities, but they don't do the complete level of testing that is required for military purposes. New facilities are still being built. Even if we do have such a facility we are still inexperienced in using such a facility.

We are not yet US, Britain or Russia who have had such facilities since the 80s. AMCA is our springboard to that.

 

[nik22]

"Rough " RCS that is got by software simulations s not true RCS ,

and

true low RCS fighters lwith RCS as low as 0.1 to 0.3 like Tejas can not be built without ," huge anechoic chambers " that existed in the west from the seventies is

your claim.

.

LOL, that was something. Just joined DFI to say thanks to you!

 

[ersakthivel]

Proposed 5th gen fighter aircraft JV yet to get defence ministry seal | Millennium Post

Proposed 5th gen fighter aircraft JV yet to get defence ministry seal

10 December 2013, New Delhi, Pinaki Bhattacharya

The Indo-Russian proposed joint venture (JV) on the fifth generation fighter aircraft (FGFA) seem not yet out of the woods, as defence minister AK Antony presented a list of four ongoing JVs in Parliament sans T-50.



The list did not include the T-50 or as Indian Air Force calls it FGFA JV that was to struck between Hindustan Aeronautics Ltd (HAL) and the Sukhoi Bureau, on the basis of a 50:50 investment sharing.

There have been reports lately that the Russian-built T-50, which was to be modified by HAL to bring in more stealth and supercruise etc, have run over time and budget. There were also reports that IAF could be reducing the size of the order, as one former top honcho said, 'The price of the contract will be phenomenally high, almost double of what we will have to pay for the Rafale.'

The senior IAF source confirmed that the FGFA JV can only take off after the Russian prototype is provided to HAL. The current date that is being talked about is 2019-2020.

In response to the question, Antony detailed the 'Present status of JV proposals between Indian Defence Public Sector Undertakings (DPSUs), Ordnance Factory Board (OFB) and Defence Research & Development Organisation (DRDO) and Russia are: Multi-role Transport Aircraft Ltd (MTAL), Indo Russian Aviation Limited (IRAL), Joint Venture for SMERCH Ammunition, Joint Venture for SMERCH Ammunition and BrahMos Aerospace.

The MTAL JV was formed between the HAL- really a new Indian entity United Aircraft Corporation Transport Aircraft - and Rosoboronexport, Russia, with both handling 50 per cent share each. 'General contract and preliminary design phase contract have been signed in May 2012 and October 2012, respectively.'

Indo-Russian Aviation Ltd, a JV company was incorporated in September 1994 with participation of 'HAL (48%), ICICI Bank (5%) and Russian partners (RAC MIG, RYAZAN, AVIAZAPCHAST) (47%).'
The JV company is for maintenance of engines, accessories, aggregates and avionics, modernisation and re-equipping all the Russian origin aircrafts. The company provides its services globally.

'Memorandum of Understanding (MoU) on joint venture to include Transfer of Technology (ToT) for co-production of SMERCH (Multi Barrel Rocket Launcher) ammunition has been signed between Ordnance Factory Board (OFB), JSC Rosoboronexport and SPLAV SPA Russia on 27 August 2012.

The BrahMos JV, one of the biggest success stories of the Indo-Russian strategic partnership was formed between DRDO India and NPO Mashinostroyenia (NPOM) Russia under an inter- governmental agreement in February 1998 for joint design, development, production and marketing of supersonic cruise missiles for armed forces of both the countries, and export to mutually agreed third friendly countries. Two variants of the BrahMos missile has been jointly developed and is under serial production in India and Russia.

So it might be better for IAF to fully participate in AMCA and tejas mk-3 stealth projects as a hedge against having a total dependence on FGFA as the cost is estimated to be huge.