LCA: News & Discussions - October 2016

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Kartik
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Re: LCA: News & Discussions - October 2016

Post by Kartik »

Thanks JayS for the images. I think the reason for the different AF and Navy Mk2 versions is that the AF Mk2 version's SOP was finalized in 2013-14 itself. Back then, the Navy Mk2 variant's design was still not finalized

ADA report 2013-14
LCA Navy Mk2 project sanctioned under FSED
Navy Ph-2 is targeted to develop two single
seat Fighter prototypes - NP3& NP4. The LCA
Navy Mk2 is being designed to meet the mission
objectives set out by the Indian Navy. The main
contributors to improvement in LCA Navy Mk2
has been identified as higher thrust engine, an
increased wing span, lighter landing gear and
structure, and improved systems layout towards
better safety and maintainability.
g) Design Consultancy with M/s EADS, Germany
is avaialble for optimization and suggestions towards achieving Final Operational Clearance
(FOC) of LCA Navy. This was carried out
successfully in the first phase of concept
evaluation in 3 stages – Data Capture, Assessment
& Suggestions. A detailed suggestions report
for improving the design was submitted and
implementation in LCA Navy development
for the current version and LCA Navy Mk2 is
being studied by Design teams at ADA and
HAL. Phase-2 of Design Consultancy towards
realization of LCA Navy Mk2 has been initialized
and contract is due to be finalized. Meanwhile,
based on the Design suggestions, design teams
involving Aerodynamics, Structures and various
groups are working on the Concept design of LCA
Navy Mk2. A Limited MoU for Concept Design
activities with ARDC, HAL was signed and Design
activities initiated with HAL as principal partner.

Performance estimation with new GE414-INS6
engine was carried out for the LCA Navy Mk-2.
In the light of this, the air intake of LCA Navy
Mk2 is being redesigned and optimized.
e) Design iterations of Aircraft surface geometry has
been undertaken based on suggestions made by
M/s EADS. LCA Navy Mk-2 geometry has been
parameterized and the several configurations
generated using the parameterized model are
being evaluated with extensive high-fidelity CFD
studies carried out at ADA and NAL (CMMACS),
Bangalore.
f) Further, preliminary planning for wind tunnel
testing of LCA Navy Mk2 has been prepared and
is due to test in suitable wind tunnel.
..

Structural schematic design of LCA Navy-Mk2
has been prepared for the baseline version. Load
analysis of critical structural members initiated.
whereas for the AF Mk2 version
SOP of LCA AF Mk2 frozen.
Kartik
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Re: LCA: News & Discussions - October 2016

Post by Kartik »

JayS wrote:
Kartik wrote:
Am in seeing things, or is that a nose chine right at the base of the pitot probe on the LCA Navy Mk2 model?? That would be as per what the ADA paper on strakes suggested was an improvement for improving Cn beta at high AoA.
No nose chin.
yes, the images you posted clarified that I was indeed seeing the nose chine/strake where none existed.

Purely aesthetically speaking, the LCA Navy Mk2 is a real beauty!
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Re: LCA: News & Discussions - October 2016

Post by JayS »

Kartik wrote:Thanks JayS for the images. I think the reason for the different AF and Navy Mk2 versions is that the AF Mk2 version's SOP was finalized in 2013-14 itself. Back then, the Navy Mk2 variant's design was still not finalized

ADA report 2013-14
LCA Navy Mk2 project sanctioned under FSED
Navy Ph-2 is targeted to develop two single
seat Fighter prototypes - NP3& NP4. The LCA
Navy Mk2 is being designed to meet the mission
objectives set out by the Indian Navy. The main
contributors to improvement in LCA Navy Mk2
has been identified as higher thrust engine, an
increased wing span, lighter landing gear and
structure, and improved systems layout towards
better safety and maintainability.
g) Design Consultancy with M/s EADS, Germany
is avaialble for optimization and suggestions towards achieving Final Operational Clearance
(FOC) of LCA Navy. This was carried out
successfully in the first phase of concept
evaluation in 3 stages – Data Capture, Assessment
& Suggestions. A detailed suggestions report
for improving the design was submitted and
implementation in LCA Navy development
for the current version and LCA Navy Mk2 is
being studied by Design teams at ADA and
HAL. Phase-2 of Design Consultancy towards
realization of LCA Navy Mk2 has been initialized
and contract is due to be finalized. Meanwhile,
based on the Design suggestions, design teams
involving Aerodynamics, Structures and various
groups are working on the Concept design of LCA
Navy Mk2. A Limited MoU for Concept Design
activities with ARDC, HAL was signed and Design
activities initiated with HAL as principal partner.

Performance estimation with new GE414-INS6
engine was carried out for the LCA Navy Mk-2.
In the light of this, the air intake of LCA Navy
Mk2 is being redesigned and optimized.
e) Design iterations of Aircraft surface geometry has
been undertaken based on suggestions made by
M/s EADS. LCA Navy Mk-2 geometry has been
parameterized and the several configurations
generated using the parameterized model are
being evaluated with extensive high-fidelity CFD
studies carried out at ADA and NAL (CMMACS),
Bangalore.
f) Further, preliminary planning for wind tunnel
testing of LCA Navy Mk2 has been prepared and
is due to test in suitable wind tunnel.
..

Structural schematic design of LCA Navy-Mk2
has been prepared for the baseline version. Load
analysis of critical structural members initiated.
whereas for the AF Mk2 version
SOP of LCA AF Mk2 frozen.
That clears up some things. Thanks. I am not getting time to go through those ADA reports.
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Re: LCA: News & Discussions - October 2016

Post by Kartik »

Cross posting from Naval LCA thread

Found a rendering of the LCA Navy Mk2 in ADA's Annual report 2014-15. What a beauty!!

Image
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Re: LCA: News & Discussions - October 2016

Post by JayS »

Kartik wrote:Cross posting from Naval LCA thread

Found a rendering of the LCA Navy Mk2 in ADA's Annual report 2014-15. What a beauty!!

Image
Thats the nose chin a la Rafale you are talking about Indranil...??
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Re: LCA: News & Discussions - October 2016

Post by JayS »

Kartik wrote: The part about the 1m fuselage length increase for the LCA Navy Mk2 was new to me, and was confirmed by ADA Director Cmde. Balaji at this AI-2017.
Your post on LCA from Aero India 2015 had mention of 1m plug for NLCA. I was looking for the earliest reference to 2m plug on the Google and it game me your post from 2015. Didn't bother looking further in past than that.
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Re: LCA: News & Discussions - October 2016

Post by Indranil »

JayS wrote:
Kartik wrote:Cross posting from Naval LCA thread

Found a rendering of the LCA Navy Mk2 in ADA's Annual report 2014-15. What a beauty!!

Thats the nose chin a la Rafale you are talking about Indranil...??
Yes sir. Kartik is not seeing things. You can see it too. Notice the bulge at the base of the canopy. It starts right after the nose cone and continues past and above the LEVCON.
Image

The front, side and the top parts look very nice. May I add that AF Mk2 also looks much more easy on the eye now. But frankly, I am disappointed in the underside. They need a little bit of artistry :P. Its not very difficult to visualize a much smoother underbody. In stead of tapering to a zero to the outer edge of the trailing wing-body fairing, taper to the inner edge of the trailing wing-body fairing (near the engine). And instead of being convex shaped all the way back, transition to a concave shape after the fattest point. Such a shape is not only simpler and easier on the eye, it will provide a much smoother wing-body join on the underside. Probably, somebody (Gagan sir) can help me draw it and ... then who knows :wink:


Also, you might have missed the last post on the AI-2017 thread
Indranil wrote:The album for AI-2017 pictures is up here.

Members can post the pictures there. After login, a directory will be created within aeroindia2017 folder. Upload your pictures there.
Kartik
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Re: LCA: News & Discussions - October 2016

Post by Kartik »

Ah, thanks. I had forgotten about it myself!

Posting that post here in full. From Aero India 2015
Here are some snippets from my conversations with ADA guys at AI-'15. Once again a long post, but I wanted to put it all down before I forget these points.

-Navy LCA Mk2 is not going to be derived from the IAF LCA Mk2. This was made clear by a young gentleman. He said that ADA and the Navy decided to go with a design to meet the IN's needs, even if it means somewhat radical changes from the IAF LCA Mk2, which is further ahead in design phase. The Navy is fully supportive of this approach. They want a variant that works best for their specific needs and requirements, even if it takes more time and effort.

-Navy LCA Mk2 first flight targeted for end-2018 or early 2019 and entry into service by 2023-24.

-The reason for the hump behind the cockpit canopy is due to area ruling. Spoke to a very senior ADA person who works primarily in aero and was associated with the Tejas program since its inception days and he confirmed this. He mentioned that this was done in close consultation with some consulting agency- most likely Airbus Defense and Space (previously EADS), but this he didn’t confirm.

- I asked if the design could be more streamlined or a bubble canopy like that on the MiG-29KUB/K couldn't be used instead of the current design. The gentleman said that the design is not finalised as yet though..further aerodynamic streamlining may occur in the future since they haven't yet tested a wind tunnel model of the Navy LCA Mk2. They will be using the HAL wind tunnel for this, since its considered to be quite good.

-The reason for the hump was that the Navy LCA Mk2 actually has become wider and significantly longer than the Navy LCA Mk1. Add to that the LEVCONS that add to the cross sectional area just fore of the wing join, and they needed a smoother blend and to avoid the sudden cross-sectional area change as seen in the IAF Tejas Mk1.

-That hump will be eventually used for something. Not certain as yet, but likely to be some avionics.

-The reason for the Navy LCA Mk2 having even greater length than the IAF LCA Mk2 was explained to be drag and internal fuel volume related. They wanted more to be carried internally and the designers of the Navy LCA Mk2 wanted to improve the fine-ness ratio.

-I asked the ADA gentleman working on the Navy Mk2 as to why the IAF LCA Mk2 didn’t get a 1m fuselage plug instead of 0.5m and he wasn’t sure..another HAL designer had earlier said that the 0.5m plug was to improve maintainability and access to certain LRUs. Not because of drag issues..clearly, not all folks at ADA and HAL are in the know and their knowledge or info is silo based. They know about their subject but very little about some other department’s issues..I asked if they compare notes amongst each other as the Navy Mk2 and IAF Mk2 groups are different. He said they do know what is happening in each other’s programs but the collaboration may not be very deep.

-The senior ADA gentleman who was associated with the LCA program since the 1980s said that the IAF requirement was for the LCA to be as small as possible and definitely no bigger than a MiG-21.

This confirms what certain other posters on BRF have stated- that the IAF required that the LCA had to able to fit into hangars sized for MiG-21’s and use existing base infrastructure, (while carrying significantly more and to a greater distance). And so the ADA guys went further and made it even smaller in length- the MiG-21Bis length w/o pitot is 14.1m, whereas the LCA Mk1 is 13.2m long without pitot. That was clearly a mistake on the part of ADA and is only now being rectified.

-The reason for the wider fuselage is what we already know- to accomodate the landing gear with its new fairing. Additional fuel tanks will also be accomodated.

-Regarding the F-16 style air-brakes- apparently it was considered but they found it to not be feasible since the structure in that region is not strong enough to withstand the heavy aero loads that will be encountered if the split airbrakes are operated. The beefing up would add weight, so as of now they're going ahead with the current air brakes. However, there is a study underway to see if the airbrake could be moved to a dedicated surface under the wing.

-Harpoon AShM is also going to be integrated to the Navy LCA Mk2 in addition to Kh-35E.

-Derby BVR missile is confirmed for the Navy Mk2 but strangely the person I spoke to wasn’t sure about Python 5. Perhaps he just wasn’t in the know. Another gentleman confirmed that the IAF Mk2 will get both Derby and Python5..he wasn’t so sure about the Astra. By the way I snapped a pic of a Tejas config with the Derby and Python 5, at the Rafael stand..have to figure out how to upload all the pics I’ve taken, which include a bunch of AMCA snaps.

-I’ve uploaded the LCA Mk1 ground based gun firing trials video onto youtube..just search for “Tejas LCA gun firing trial”. It’s a short 5 sec clip. The gun trials were conducted to validate the vibration characteristics and to check whether structures, internal avionics and electronics can withstand it. No issues were seen during the trials.

-L-273 Uttam AESA radar will be the likeliest radar for the Navy LCA Mk2. This clears my confusion from last Aero India where the Deputy PD said that the Elta 2032 would be the radar on the Navy Mk2. Clearly, 2 years is a long time and lot has progressed since.

-No IRST requirement from the IAF or IN as yet. ADA guy said that they won’t propose new equipment if the user doesn’t have a requirement for it.

-Further work to be done for shaving off another 200 odd kgs from the landing gear weight for the Mk2

-There is no change in the height of the vertical fin. The additional height of the Navy LCA Mk2 has to do with the longer stroke length of the oleos. It just sits higher than the IAF variant.

-Regarding the weights, I’ll post separately.

-N-LCA Mk1 bring back max weight is in the ~10,500 kgs range..with an empty weight of almost 7900 kgs thanks to the beefed up structure, arrestor hook and new landing gear, the corresponding payload that can be safely brought back (coupled with enough fuel for a couple of missed traps on the carrier) will be in the range of ~2000 kgs. Fuel dump system hence is a mandatory feature for the Navy LCA in case of an emergency soon after take-off. But I’m a little hazy on this part of the conversation so don’t quote me on this as the final figures are not in the public domain as yet.

-We will likely see 8G capability for the Navy LCA Mk2 and not 9G. Thanks to the added structural weight over the IAF LCA Mk2. But the gentleman remarked that even the MiG-29K is not 9G capable and the Super Hornet is 7.5G capable thanks in part to the added weight and in part to the wing folding mechanism that they feature. So the IN may have no issues with 8G capability. AFAIK, only the Rafale M is a 9G naval fighter.

-No wing folding mechanism required for the Navy LCA Mk2 even with the additional wing span (viz. thanks to the fatter fuselage) since it is still quite a small aircraft by comparison to other navy fighters

-Navy LCA Mk2 air intakes will be bigger for sure to cater to the higher mass flow rate of the F-414 engine. The air intake duct will also been lengthened.

-LEVCONs for the Navy LCA Mk1 are currently only used in 1 position..but the FCS will eventually allow for 4 positions- +30 deg, 0 deg, -10 deg and -20 deg.

-the LCA Mk1 has ~180 kgs of ballast just aft of the nose, below the pilot. Done to be able to keep the CG within a defined range for different configs of weapons and drop tank loadouts. This may be targeted for reduction on the Mk2, possibly by using the space for some equipment. Got this from a young HAL guy.

-Navy LCA Mk2 will get a fixed probe, not a retractable one as per one gentleman. Last Aero India I was told it would be a retractable one. Unfortunately, Cmdr Sukesh Nagaraj wasn’t there on the day I visited, otherwise we’d have got even more info.

-Currently the LCA Mk1 uses flares similar to what the MiG-21, MiG-27 and MiG-29 (I may have gotten this list wrong, not completely sure) use. It is an indigenously developed flare that works in one part of the spectrum..but a new multi-spectral flare is being developed that covers a wider band for enhanced protection. This will likely be ready for the Mk2.

-Saw a new pylon adapter that has been developed for the Jaguar- to carry, in the words of the gentleman displaying it, “a boxy type weapon” (he didn’t know what it was though, perhaps the CBU-105 Sensor Fuzed Weapon?). The new rack uses pneumatics instead of pyro bolts and consequently is easier to maintain since the pryo leaves behind residue that needs to be cleaned. Plus this one is less than 1/3rd the cost of the imported pylon adapters. I asked him if a multiple ejector rack was being developed and he said no. But if a requirement arose, they could do so.

-Saw the LCA Mk2 cockpit simulator and the cockpit displays. Excellent clarity and they were significantly bigger than on the Mk1. The cockpit itself is a tight fit (I waited for my turn to get to sit inside but some HAL employee’s relatives were given a much longer than usual demo and I was running out of time). The simulator graphics were excellent. Not a full motion sim, but perfect for newbie pilots to get accustomed to the cockpit and the general flying characteristics of the Mk1/2.

-Navy LCA Mk2 will have a wider angle HUD, as it’s a Navy requirement. The IAF has no such requirement, but a new HUD is being developed with better characteristics..not sure what those characteristics are since the person didn’t tell. If jingos want a frameless HUD, ala Gripen or Rafale, they’re going to be disappointed. That ain’t happening.

-HUD symobology is good..been developed in close collaboration with NFTC Test pilots..it took me ~ 10-15 seconds to figure out what was being displayed on the HUD (since it was being displayed on the screen in front of us we all could see it) but that was primarily flight parameters. Since I didn’t get a chance to sit in the cockpit, I couldn’t ask them to run me through different radar modes, or to ask about data fusion or how such data will be displayed. Perhaps it’s too early to ask about data fusion for the Mk2 program. It will most likely be an IAF and IN requirement though.

Will post more as and when I remember it..got a few snippets on the AMCA also.
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Re: LCA: News & Discussions - October 2016

Post by Kartik »

Indranil wrote:
JayS wrote:
Yes sir. Kartik is not seeing things. You can see it too. Notice the bulge at the base of the canopy. It starts right after the nose cone and continues past and above the LEVCON.
Actually, I was referring to the nose pitot base chine. Similar to that on the Gripen and MiG-29. That was proposed for the LCA based on studies that demonstrated how it made the airflow more symmetrical and improved CnBeta

Image

CFD studies with nose chine and strake
Indranil wrote: The front, side and the top parts look very nice. May I add that AF Mk2 also looks much more easy on the eye now. But frankly, I am disappointed in the underside. They need a little bit of artistry :P. Its not very difficult to visualize a much smoother underbody. In stead of tapering to a zero to the outer edge of the trailing wing-body fairing, taper to the inner edge of the trailing wing-body fairing (near the engine). And instead of being convex shaped all the way back, transition to a concave shape after the fattest point. Such a shape is not only simpler and easier on the eye, it will provide a much smoother wing-body join on the underside. Probably, somebody (Gagan sir) can help me draw it and ... then who knows :wink:
My guess is that now that they've paid a lot more attention to the area ruling, the under-side reflects what they need to do to keep drag to a minimum.
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Re: LCA: News & Discussions - October 2016

Post by srai »

Great discussion guys!

Can we create a Project BRF - LCA sticky and curate it with ADA and NAL reports/studies/photos along with AI reports?
Last edited by srai on 01 Apr 2017 10:52, edited 1 time in total.
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Re: LCA: News & Discussions - October 2016

Post by SaiK »

ramana
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Re: LCA: News & Discussions - October 2016

Post by ramana »

Dileep, From Handbook of Aeronautics, Chapter on Shock and Vibration, typical environment for sat laugh vehicles is 0.04 g^2/Hz upto 2000 Hz. So 1 g^2/Hz is very high environment.

Random Vibration has sine and shock components due to the bell mouth nozzle.
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Re: LCA: News & Discussions - October 2016

Post by Dileep »

Ramana, I am a bit concerned about the numbers being asked. I will email you the actual spec.

We have an important review on 4th, so any better clarity would come to use.
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Re: LCA: News & Discussions - October 2016

Post by Dileep »

Folks, please don't read too much into the display models. They are made by 'artisans' with no clue on aeronautics. The 3D models/renderings have better reliability, but I wouldn't trust them either.
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Re: LCA: News & Discussions - October 2016

Post by JayS »

Indranil wrote: Yes sir. Kartik is not seeing things. You can see it too. Notice the bulge at the base of the canopy. It starts right after the nose cone and continues past and above the LEVCON.
I got what Kartik was referring to, and replied accordingly. And I got what you were referring to as Nose chin as well. But I couldn't imagine how exactly until I saw the LCA Navy MK2 CAD image. I didn't think they wold tinker with forebody ahead of the inlet. Is it for improved air intake or for improved Area ruling..??
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Re: LCA: News & Discussions - October 2016

Post by SaiK »

wouldn't be worth to build a 1/6th or 1/4th size actual model that could be used as an UCAV as well? I guess engines are the biggest headache
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Re: LCA: News & Discussions - October 2016

Post by JayS »

SaiK wrote:wouldn't be worth to build a 1/6th or 1/4th size actual model that could be used as an UCAV as well? I guess engines are the biggest headache
Aerodynamics would not work out of the box for such type of scaling. LCA is not same as 1:4 LCA.
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Re: LCA: News & Discussions - October 2016

Post by SaiK »

JayS, can you say more on that? what factors that plays in that can't be scaled? thx
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Re: LCA: News & Discussions - October 2016

Post by Indranil »

JayS wrote: I got what Kartik was referring to, and replied accordingly. And I got what you were referring to as Nose chin as well. But I couldn't imagine how exactly until I saw the LCA Navy MK2 CAD image. I didn't think they wold tinker with forebody ahead of the inlet. Is it for improved air intake or for improved Area ruling..??
I am sure it helps with the area ruling. In the Mk1, there was a sudden jump at the intake-lip region, so a bulge before it must be helping. They obviously had to have a bulge to push the wing joins out. However, I was thinking why did they not go with a platypus nose (ala Su-34) or chiseled one (ala F-22) which would have helped with RCS and provide the necessary stability which they are trying to achieve with the nose chine and the fuselage. The answer in my mind is that they don't want to tinker too much with the air intakes other than provide for higher airflow and better pressure recovery at low speeds. Consequently, you have that pinched bottom look. Will it help in ram effect into the air intakes at high AoA. May be, but not be as much as in the Rafale.
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Re: LCA: News & Discussions - October 2016

Post by srai »

Kartik wrote:...
-Derby BVR missile is confirmed for the Navy Mk2 but strangely the person I spoke to wasn’t sure about Python 5. Perhaps he just wasn’t in the know. Another gentleman confirmed that the IAF Mk2 will get both Derby and Python5..he wasn’t so sure about the Astra. By the way I snapped a pic of a Tejas config with the Derby and Python 5, at the Rafael stand..have to figure out how to upload all the pics I’ve taken, which include a bunch of AMCA snaps.
...
Until Astra gets an indigenous seeker, there would limitation on which platform it can be integrated with. Current Agat seeker (R-77) being used would make it compatible with Russian platforms, Su-30MKI and MiG-29. Maybe they can interchange Derby seeker in Astra and that would make it compatible with LCA EL/M-2032/52 radar. Then a third option would be to have Mica seeker on Astra and that would make it compatible with Mirage-2000 and Rafale.
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Re: LCA: News & Discussions - October 2016

Post by Cain Marko »

Are we looking at Derby ER or the original one? If the former comes through, they might not push too hard and fast for the Astra.
Last edited by Cain Marko on 02 Apr 2017 20:15, edited 1 time in total.
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Re: LCA: News & Discussions - October 2016

Post by JayS »

Cain Marko wrote:Are we looking at Derby ER or the original one? If the latter comes through, they might not push too hard and fast for the Astra.
Durby ER will be integrated with LCA (source Tejas FB page)
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Re: LCA: News & Discussions - October 2016

Post by ramana »

JayS, How many Derby and Python in full load out is LCA to carry?
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Re: LCA: News & Discussions - October 2016

Post by JayS »

ramana wrote:JayS, How many Derby and Python in full load out is LCA to carry?
LCA can carry maximum of 2CCM (outboard pylons) + 4 BVR (midboard + inboard) missiles as of now, AFAIK.

ADA might be able to integrate dual (parallel) CCM pylons or CCM+BVR pylons on mid board or inboard pylons in future. Another possibility is of having tandem pylon for CCM at centre fuselage point. But the more stuff you put on the pylons, the more restricted the performance becomes. While it looks good in brochures, it perhaps would have little practical value to put too many missiles on LCA.

For CAP I suppose LCA typically would be flying with 2CCM + 2BVR + 2 EFTs.
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Re: LCA: News & Discussions - October 2016

Post by Neshant »

I always thought the way air-to-air missiles are recessed in the fuselage of the Tornado offers the best compromise between stealth, simplicity, and performance (without the need for a cavernous internal weapons bay). The latter totally screws up the aerodynamics and ruins the agility of the plane.

A missile which is recessed in the fuselage of the MK2 and has fins that flip out after launch would be perfect. A lot better than building a plane with an internal weapons bay that ends up being too bulky.

4 missiles recessed in the fuselage :
Image
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Re: LCA: News & Discussions - October 2016

Post by brar_w »

That is not a stealthy configuration. The radars can be anywhere, in front, above or below an aircraft and in most of those cases the missiles will increase radar return when compared to a clean aircraft (the aircraft has a dynamic RCS since it is maneuvering and not merely flying straight and level towards an emitter), not to mention that a clean non RCS optimized aircraft will still have a significant return compared to something that is optimized for low radar signature.
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Re: LCA: News & Discussions - October 2016

Post by Cain Marko »

Neshant wrote:I always thought the way air-to-air missiles are recessed in the fuselage of the Tornado offers the best compromise between stealth, simplicity, and performance (without the need for a cavernous internal weapons bay). The latter totally screws up the aerodynamics and ruins the agility of the plane.

A missile which is recessed in the fuselage of the MK2 and has fins that flip out after launch would be perfect. A lot better than building a plane with an internal weapons bay that ends up being too bulky.

4 missiles recessed in the fuselage :
Image
The typhoon takes this semi recessed approach, and the raffle to some extent. Great idea for a non vlo platform like lca mk2 and reduces drag too. Btw, I'm not sure that internal bays hurt agility, they probably increase it compared to external stores. Just look at the pakfa or raptor. Extremely maneuverable in all regimes.
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Re: LCA: News & Discussions - October 2016

Post by Cain Marko »

JayS wrote:
Cain Marko wrote:Are we looking at Derby ER or the original one? If the latter comes through, they might not push too hard and fast for the Astra.
Durby ER will be integrated with LCA (source Tejas FB page)
Thanks JayS, great news.
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Re: LCA: News & Discussions - October 2016

Post by brar_w »

Cain Marko wrote:
The typhoon takes this semi recessed approach, and the raffle to some extent. Great idea for a non vlo platform like lca mk2 and reduces drag too. Btw, I'm not sure that internal bays hurt agility, they probably increase it compared to external stores. Just look at the pakfa or raptor. Extremely maneuverable in all regimes.
Recessed carriage was present in a lot of 4th generation designs. The F-14, and F-15 also carried missiles like that. It obviously has aerodynamic advantages but remember RCS is measured from all aspects and a radar can be anywhere including on the ground looking up.
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Re: LCA: News & Discussions - October 2016

Post by Cain Marko »

Yes, I'm thinking only of 4 gen birds like LCA mk2 although it might make some difference rcs wise in a head on angle.
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Re: LCA: News & Discussions - October 2016

Post by JayS »

arshyam wrote:Any idea what this soap-like thing is? I asked the ADA guy at the display, but he was from the avionics side and didn't know.

Image

If is talks like a soap, walks like a soap, looks like a soap.... ;)
These are GPS antennas. Info courtesy Tejas FB admin.
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Re: LCA: News & Discussions - October 2016

Post by Neshant »

brar_w wrote: Recessed carriage was present in a lot of 4th generation designs. The F-14, and F-15 also carried missiles like that. It obviously has aerodynamic advantages but remember RCS is measured from all aspects and a radar can be anywhere including on the ground looking up.
I'd go as far as an internal weapons bay for a few air to air missiles in the MK2 but no further.

Having fuel tanks, bombs and pods stored internally to fulfill a multi role criteria begins to ruin the advantages of a small, agile fighter.

MK2 should have a dedicated air superiority configuration and those planes should not be carrying bombs or external fuel tanks into the combat zone.
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Re: LCA: News & Discussions - October 2016

Post by brar_w »

The MK2 is not having an internal bay. There are pictures of the design they have created in here and the NLCA thread. Its configuration is pretty much sealed. You obviously need extra fuel since you are using a larger engine.
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Re: LCA: News & Discussions - October 2016

Post by Neshant »

I know the MK2 won't have an internal weapons bay.

I'm speaking theoretically.

If it were to be designed, an internal weapons bay only for air to air misses rather than everything would be ideal.
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Re: LCA: News & Discussions - October 2016

Post by Gagan »

JayS wrote:
arshyam wrote:Any idea what this soap-like thing is? I asked the ADA guy at the display, but he was from the avionics side and didn't know.

If is talks like a soap, walks like a soap, looks like a soap.... ;)
These are GPS antennas. Info courtesy Tejas FB admin.
That is NOT a GPS antenna.
It is a piece of soap/clay to clean the windshield. Or just a piece of soap period

This is an antennae:
Image

Image
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Re: LCA: News & Discussions - October 2016

Post by Karan M »

those are IFF antennae.

typical GPS antennae.
http://www.verdanttelemetry.com/product ... _id=search

or

http://www.cobham.com/communications-an ... -antennas/

looks very similar to that soap bar no?

having said that, the erosion is non uniform and no screws are visible, so perhaps soap
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Re: LCA: News & Discussions - October 2016

Post by Dileep »

Who is going to mount something right straddling the joint of two panels? Looks like something just kept there.
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Re: LCA: News & Discussions - October 2016

Post by shiv »

Maybe we can approach this question from another direction. What brand of soap could it be? Once we identify that we can ask who uses that among the LCA team. I think it is Dove.
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Re: LCA: News & Discussions - October 2016

Post by Rakesh »

:lol:
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Re: LCA: News & Discussions - October 2016

Post by PratikDas »

Dileep wrote:Who is going to mount something right straddling the joint of two panels? Looks like something just kept there.
Those bars of soap have been seen in flight! [and this was brought to the attention of the forum by someone else, just can't remember who]

Click for hi-res

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