AMCA News and Discussions

tushar_m · Post by **tushar_m** » 09 Sep 2015 20:12

i never get the point of demanding an engine of 110kn power .

there is no such engine that deliverers this power .Basically this is the middle ground between the 90kn engines & 120 kn engines (west or Russia)
maybe use a scale down version of AL31(or 117) similar to what Chinese have done for their J10's. If that engine is good enough for single engine fighter than the idea would work for twin engine fighter as well.

Someone here has any idea for the demand of 110kn engine that doesn't exit by ADA/HAL etc ????

brar_w · Post by **brar_w** » 09 Sep 2015 20:55

Down-rating an engine rarely allows for massive weight savings and by opting for a twin 31-F the AMCA will need to account for at least 2000 pounds ( 900Kg) of added design weight. Part or all of this would come from the higher thrust which also then means higher fuel consumption to account for the higher thrust. That has a cascading effect on combat radius which then impacts the design from an internal fuel requirement perspective (generally makes the aircraft larger all other things being equal). 110KN is doable for both the EJ series and the F414 and its largely a matter of need, cost and risk. Notice that the GE-F404 to GEF414 transition added very little weight compared to the increase in thrust and the F414-400 to F414 EPE changes are not going to add significant amount of engine weight since the higher thrust is a function of increasing airflow, inserting new materials (which may even be lighter) allowing for the engine to run hotter and by tweaking the FADEC. If you need a 122Kn - 130+Kn class engine then the AL-31F would seem a good option but if your requirement is in the 100-110Kn class then you are much better off to take the lighter higher thrust to weight engines and making material changes to get higher thrust from them. The GE engine would have to deliver around 12% more thrust to meet that requirement (vs. a target from the EPE of around 20%) while the Eurojet would need a larger thrust increase of around 20-22%. Both are doable if there is adequate funding in place.

The 110Kn requirement for the AMCA most likely has a built in margin that is generally associated with design requirements.

Indranil · Post by **Indranil** » 09 Sep 2015 21:12

For the size of aircraft that AMCA is envisaged, that is optimum power and size. If you put 2 AL-31P sized engines, the optimal size is the Su-30/F-15. If you look at the current medium-weight fighters they all have engines with approx ~85kN thrust and ~0.9m diameter. For a next generation plane, ADA is aiming for 15% increase in TWR, which is completely at par with normal aircraft and engine development. Plus, 110kN is not unobtainable. Both the EJ-200 and F414s had that in their roadmaps, should sufficient demand arise. For the Eurozone, given its economic situation and that Eurofighters are the only users of the EJ-200 engine, this development took somewhat of a back seat (I still expect this variant to come out, albeit with more delay). For the Americans, they are not sure how much longer the F-18s will play a pivotal role. But now, if AMCA would take a 110kN engine and LCA Mk2s can be retrofitted with the same during midlife upgrades, one is looking at upwards of 1200 engines in India alone! GE can license the same technology to Volvo and Samsung Techwin! Now, that GTRE is developing such an engine, this is a great test for the DTTI setup.

P.S. brar_w and I must have been typing at the same time. Hence the redundancies in our posts.

sankum · Post by **sankum** » 18 Sep 2015 05:18

Image of evolution of AMCA

shiv · Post by **shiv** » 18 Sep 2015 09:58

sankum wrote:Image of evolution of AMCA

Thanks for posting this very interesting image

3B-07 is the version that Prodyut Das criticzed as having a tailfin that looked like the HPT 32 tailfin

3B-04 to 07 seem to have trapezoidal tailplanes. The rest are cropped triangle

3B 07 is the only one i which the exhaust pipes appear not to stick out as much as the others - and appears "shaded" by the HPT-32 tailfin. This is because the 3B-07 is the only model in which there is a longer segment of fuselage visible between inboard trailing edge of mainwing and inboard leading edge of tailplane. The two wings are placed closer together in all the other models. The 3B-07 appears to be a one-off that has been discarded.

sankum · Post by **sankum** » 18 Sep 2015 12:06

The Advanced Medium Combat Aircraft:
A Technical Analysis

Gyan · Post by **Gyan** » 18 Sep 2015 13:48

sankum wrote:The Advanced Medium Combat Aircraft:
A Technical Analysis

I also feel that the issues raised by the article are pertinent. LCA Mark-2 will have 3ton fuel with 98kn engine. AMCA is proposed to have only 4 ton fuel with 110x2=220kn engine power. Hence the range of AMCA may be substantially lower than estimated.

Also the proposed empty weight for AMCA of 9 tons seems difficult to achieve.

I think we should use the technology and manufacturing base of Su-30MKI ie for instance AL-31 engine etc; and then design the AMCA around known engineering parameters, then make evolutionary improvements batch wise. Something like what Chinese are doing with J-20.

I think we should look for AMCA with AL-31 engines (123x2=246kn), empty weight of 12-13tons and fuel capacity of 8-10tons. We will fall short of super cruise capability which can be achieved once more powerful engines (and more fuel efficient engines) of 140-160kn become available (post 2030).

i think that rather than concentrating on costly imports, fake JVs and half hearted indigenisation, we should have two programmes for stealth aircraft being;-

Su-stealthini to leverage the Su-30MKI's R&D and Manufacturing base
AMCA to leverage LCA's R&D and Manufacturing base

NRao · Post by **NRao** » 18 Sep 2015 18:19

1) All the fins in that specific diagram are canted. Besides they were used for testing various aspects. So, one should not compare the various design components from model to model. It is entirely possible, as an example, for them not to care for a fin (say), while testing a bay

2) That article is confusing too. Seems like they have picked up what they could get and come to a conlcusion based on their own biases.

This seems to indicate an incomplete understanding of what it is that a 5th-generation fighter actually does

So, what does a 5th gen plane do? Something I have been asking for some time now. (Again, not a knock on these authors).

Also, as an aside, my observation is that these two authors have been swept away by the tide.

3)

I think we should use the technology and manufacturing base of Su-30MKI ie for instance AL-31 engine etc; and then design the AMCA around known engineering parameters,

That, I thought, was the PAK-FA. No?

Take the MKI, rotate the engine inlets, flatten the plane (by rotating the inlets it happens to some extent), merge the canards with the leading edge of the wing, cant the fins and make them movable. That is how I had characterized it when I first saw the very beautiful PAK-FA.

The AMCA may not be as advertised, but India - IF India wants to be a player - needs it. Of course, if India wants to import, import, import, then pack it up. Yes, miniaturization, stealth techs, etc are crucial to such developments. But, no use talking about them. Indians should wade in, get their hands dirty, instead of writing more papers. Need to stop crabbing.

The AMCA will do well. How well? OK, agreed, that is TBD.

ShauryaT · Post by **ShauryaT** » 18 Sep 2015 19:10

sankum wrote:The Advanced Medium Combat Aircraft:
A Technical Analysis

A few things of note in the article, if someone has more information on EOTS, please enlighten. Thanks.

The AMCA also does not appear to have a conformal Electro-Optical Targeting System (EOTS). This
means it will have limited ground strike capabilities – restricted to GPS-guided weapons only. This
means both laser-guided weapons and optically guided weapons required for pin-point precision as
well as the engagement of moving targets would not be available to the AMCA. In effect this would
mean that it duplicates the role of the F-22, which is overwhelmingly an air superiority fighter with at
best a secondary ground strike capability. Unlike the single vendor situation of the conformal IRST -
the Russian MiG-35 seems to have a system similar to F-35's EOTS – the OLS-K (though once again
its spherical shape means it is radar reflective). The OLS-K, like the F-35's EOTS, is constructed of
artificial leuco-sapphire. Various attempts at tracking down local producers of leuco-sapphires for
this paper yielded no results and possibly points to a local production deficit that will have to be
overcome. Given the highly limited nature of the market, though, it might be impossible to create
economically viable manufacturing facilities for leuco-sapphires in India.

sankum · Post by **sankum** » 19 Sep 2015 00:04

AMCA dimensions estimates of main internal weapon bay 4.3-4.4m by 2m and a uniform depth of 55-60cm shows to be able to carry 5 R77 BVR AAM in parallel config.

Its more like both main bays of Pakfa in parallel with lesser length and depth and be able to carry 4 650kg Kh-58UShKE of folded dimensions of 4.2m by 0.4m by 0.4m.

Should also be able to carry 4 Astra mk1.

Saurav Jha has said that the internal payload of Amca was being raised to 3T.

Internal payload of earlier reports was of 1.5-2T and internal fuel of 4T and empty weight of 9T was for a earlier planned MTOW of 20 T while present MTOW has increased to 25T and empty weight can be expected to be in region of 11-12T.

Length of AMCA is estimated at 17.5m and width estimate from diagrams is at 11.5m and folded wing tips width of 7.8m for naval version just like mig 29k can be expected.

sankum · Post by **sankum** » 19 Sep 2015 03:33

2 SRAAM for stealthy mission can be carried in stealthy conformal pods which can be fitted to innermost wing pylons just like Pak fa (where it is fixed) and for non stealthy mission carried on outermost wing pylons externally.

Compact BVR AAM with folded fins should allow 6 nos to be carried in main internal bay.

Upto 10-12nos Small diameter bombs can be carried internally and 4 nos 250-750Kg PGMs internally.

Overall I am impressed by internal weapon bay design and capability though it is at a cost of lesser internal fuel.

shiv · Post by **shiv** » 19 Sep 2015 13:25

sankum wrote:
Upto 10-12nos Small diameter bombs can be carried internally

These are American weapons designed to be accurate using American infrastructure and support. For AMCA?

Karan M · Post by **Karan M** » 19 Sep 2015 13:40

if we can buy harpoons and SFWs we can get SBDs too or local versions

shiv · Post by **shiv** » 19 Sep 2015 13:53

Karan M wrote:if we can buy harpoons and SFWs we can get SBDs too or local versions

True. So the AMCA of the future is being designed to fit current American weapons - should keep American assembly lines going longer than expected. Unless the ruthless Yanks close the line down like they did for C-17.

More seriously - I think the SDB is a limited utility weapon searching for a bigger role and the AMCA will never use it. But people will have to wait many years to find out. The SDB was an American solution to an American problem. We should not create the same problem in the AMCA and then take the American solution; that would be fitting the problem to the solution. As for "local weapons" I have not heard of any Indian plans to build something similar. I think India is more likely to take the Russian route - with the Russians having a far more interesting set of guided weapons being readied for their PAK-FA.

I do think we need a thread for Russian weapons and tech

NRao · Post by **NRao** » 19 Sep 2015 14:17

July, 2015 :: US offers Small Diameter Bomb to Su 30 and Tejas

The US offers it's modern Small diameter glide bomb to equip it in the light combat jet Tejas and the Long Range Su 30 MKI, as Precession Bombing and pin point strike is a game Changer in future warfare and asymmetric warfare, India also planning to develop it's own small anti armor missiles, as Defense correspondent Saurav Jha reveals about the Indian Plans of developing own anti armor missile same like US made Hell fire and European Brimstone. But all of these systems are not having good range, also it needs the launching platform comes close to the Target before engining, or need a visual identification before engaging.

But the SDB is entirely different it can glide through the air and travels more than 100 kilometers and hits the Moving vehicle at pin point accuracy with highly lethal fragmentation warhead. the SDB is low in cost, weights low. but the performance is superior with the Tri seekers the Target acquisition and pin point strike become more easier. as the main aspects of lock on after launch, means it acquire targets his self.

The SDB comes with three Guidance system, first is the GPS/INS based guidance to get a approximate target location of moving or stationary Target, the on board mmW seeker tracks the inbound threat, whether it's highly moving or stationary, and the Imaging infrared seekers identifies the priority targets, thus three makes the SDB hit the Target very accurately, the accuracy calculated less than one meter when the SDB Launched far from 60 kilometer or less.

So far India has many types of PGM/LGB's which way too heavy more than 250 kg to 750kgs. Bombs like Russian made OFAB dumb bombs, KAB 500,1000, 1500 laser guided Bombs, Israeli made Improved fragmentation Bombs,variety of other PGM's like Gabriel and other, American made CBU 105 Cluster Bombs, and the desi made Sudharshan LGB, along with two or three models of Glide Bombs and anti armor missiles are at developing stage, But those Indian Glide bombs and anti armor missiles is still in development stages would require another three to five years before adopted into the Airborne Platforms.

Karan M · Post by **Karan M** » 19 Sep 2015 15:03

shiv wrote:
Karan M wrote:if we can buy harpoons and SFWs we can get SBDs too or local versions
True. So the AMCA of the future is being designed to fit current American weapons - should keep American assembly lines going longer than expected. Unless the ruthless Yanks close the line down like they did for C-17.

More seriously - I think the SDB is a limited utility weapon searching for a bigger role and the AMCA will never use it. But people will have to wait many years to find out. The SDB was an American solution to an American problem. We should not create the same problem in the AMCA and then take the American solution; that would be fitting the problem to the solution. As for "local weapons" I have not heard of any Indian plans to build something similar. I think India is more likely to take the Russian route - with the Russians having a far more interesting set of guided weapons being readied for their PAK-FA.

I do think we need a thread for Russian weapons and tech

Buying SDBs in the interim but relying on thier local equivalent is ok.. especially if we make our own version. Your impression is that the SDB is an American solution to an American problem.. I disagree.. I think its a good tool to maximize loadouts and is a universal weapon well in line with multiple developments worldwide on the same line...as sensors get more precise, compact the ability to make compact munitions increases and weapons emerge.

The key is to have small sensors which RCI is working on. As regards not hearing of Indian plans to build anything similar look into the DRDL presentation made by VKS a couple of years back.. a range of options are being worked on for small, compact sized weapons. India's approach is not going to be Russian or American.. these are somewhat meaningless . its going to be driven by the kind of sensors we have access to and what we can make..

See page 25: http://www.aeromag.in/sites/default/fil ... tion_1.pdf

Miniaturized system weighing just about
150gram is a reality today which was
weighing about 50kg, years ago. During
this journey, all the sensors and systems
available with the advanced nations,
whether it is DTG, FOG, RLG, high accuracy
Accelerometers, Hybrid Navigation
Systems and modern Algorithms, all
have been made indigenously for various
applications. RCI houses an advanced
Navigation and Embedded Computers
laboratory which is at par with any world
class facility.
In the field of control actuation systems,
we are self sufficient. As a matter of fact
several types of actuation systems like
hydraulic, electro mechanical & pneumatic
actuation systems and the guidance
algorithms and simulation technologies
also have been developed. The state of
the art guidance schemes developed by
RCI are flying many of our missile systems
today.

In short if DRDO/partners can provide the IAF a small bomb with precise sensors that can fly through a window and do the job of a much larger bomb (which entirely depends on how precise it is) and hence allow its fighters to maximize their firepower, it will be a net plus. A single Su-30 with a hundred SDBs which can fly out and attack multiple targets will be a huge force multiplier. Modern aircraft are very vulnerable to fragmentation - a bunch of bombs smacking around a flightline will effectively destroy the flightline. However, if a target is not really precisely known location wise, you'll need large munitions with hundreds of kgs warheads. So it goes..

However, our gating factors are basically that we are at stage 1 in our A2G weapons programs and hence will take 2-3 cycles to achieve the sort of compact packaging western designers are now deploying. Per se not because they are American or Russian but because they have invested in the products to that degree.
We will need a mix of systems, and from what we know DRDO/DRDL/RCI are working on all these.. most are classified and hence it will take time for the results to emerge publicly. Its interesting that they haven't even released details of their guided bomb which flew 100 odd kms last year.

brar_w · Post by **brar_w** » 19 Sep 2015 15:05

I think India is more likely to take the Russian route - with the Russians having a far more interesting set of guided weapons being readied for their PAK-FA

Most guided weapons being developed have a western equivalent as well and most of those are planned for stealth fighters, UCAV's etc. There is no reason that you cannot do both i.e. develop large magazine depth weapons while also developing larger guided weapons for a lower number of targets per sortie (but larger effects on target). There will be times when you wished your strike fighters could hang in longer because the target sets are large while other targets would present much more protection or size requiring much larger weapons. No one developing small diameter class weapons (Europe, USA or Israel) is giving up on heavier weapon development because of this. For the IAF it shouldn't be an Either Or choice but as Karan pointed out (the programs currently ongoing) a wide range of munitions to develop and invest in for future use covering a wide possible target sets and strike scenarios.

kit · Post by **kit** » 19 Sep 2015 15:13

SDB 2 is on the way .. i kinda remember an article mentioning SDB being not so effective as supposed ?

brar_w · Post by **brar_w** » 19 Sep 2015 15:24

kit wrote:SDB 2 is on the way .. i kinda remember an article mentioning SDB being not so effective as supposed ?

viewtopic.php?f=3&t=7088&p=1902976#p1902976

shiv · Post by **shiv** » 19 Sep 2015 17:24

Karan M wrote: In short if DRDO/partners can provide the IAF a small bomb with precise sensors that can fly through a window and do the job of a much larger bomb (which entirely depends on how precise it is) and hence allow its fighters to maximize their firepower, it will be a net plus. A single Su-30 with a hundred SDBs which can fly out and attack multiple targets will be a huge force multiplier.

This is the exact problem I have with the SDB - its pinpoint accuracy and low risk of collateral damage makes it suitable only for a niche role played by the Israeli Air Force against Palestinians and US air power versus Baghdad and Libya and its role against vehicles and single buildings in Afghanistan.

We have been talking and reading so much about what the IAF has had to do and we are looking at putting airfields out of action, large areas where fuel, ammunition or vehicle concentrations are built up, factories with multiple buildings, refineries, electrical substations, railway marshalling yards, 3 km long tailbacks of vehicles taking supplies to the war front, 3/4 km long trains, a broad and deep front of attacking tanks across many sq km of territory, a 200 hut enemy camp hidden in the mountains like Muntho Dalo. In two wars, 1965 and 1971, the only "through the window" type of attack was on the Governor's bungalow in Dhaka shortly before the surrender. This sort of multiplicity of targets require plenty of explosive power and demand healthy collateral damage effects, which makes the SDB only a "little toe" in the limbs that constitute what the Air Force needs for attack. My problem is the way the name SDB keeps coming up as if it is going to make a huge difference. It is not.

NRao · Post by **NRao** » 19 Sep 2015 18:05

Like it or not, wars are going PC. That is perhaps the only time one talks of collateral damage and the like.

Two things. First anyone that wants to take an air strip or the like will use something more appropriate than a SDB. Even the US.

Secondly, the question is if India has a need within a PC war. However small I think there is a need. Neither Pakistan nor China will hesitate to hide behind civilians. So there a need for weapons such as the SDB.

WRT Russia, hard to say at this point in time. As an example what are their infrastructure in Syria to conduct a network centric war? I do not know. But such things will dictate - to a great extent - what direction they will go.

In and around India, network is it. SDB will fit if there is a need.

shiv · Post by **shiv** » 19 Sep 2015 18:57

NRao wrote:Neither Pakistan nor China will hesitate to hide behind civilians. So there a need for weapons such as the SDB.

WRT Russia, hard to say at this point in time. As an example what are their infrastructure in Syria to conduct a network centric war? I do not know. But such things will dictate - to a great extent - what direction they will go.

In and around India, network is it. SDB will fit if there is a need.

We are going OT, Neither the US nor Israel have given a damn about civilians if it comes to winning war - and the civilian casualty thing is more of a domestic political requirement for the US. Not some moral dimension. Clearly a lot of people have been fooled into thinking that there is some kindness being applied by using SDB like weapons - which is nonsense.

War is war. Those who hide behind civilians will get hit along with those civilians - especially in a nation like Shitistan where the militia are dressed in civilian clothes and live among civilians. So I do not for one minute get fooled by this PC rhetoric when it comes to war. No more posts from me on this subject on this thread.

NRao · Post by **NRao** » 19 Sep 2015 19:27

Clearly a lot of people have been fooled into thinking that there is some kindness being applied by using SDB like weapons - which is nonsense.

Biases should not get in the way of discussions.

Today as we post India is leading in an effort, with the US in tow, on this very topic: how to train future soldiers to be statesmen too.

PC for you. No one is getting fooled. But some are being left behind either due to a lack of research or a built in bias.

IMHO.

vishvak · Post by **vishvak** » 19 Sep 2015 21:15

USA involvement in AMCA? News to me, regardless of US in tow and putting it on soldiers already as statesmen etc etc.

NRao · Post by **NRao** » 19 Sep 2015 21:46

The latest AWST has an article on stealth (by Sweetman!!!!!!!). He pretty much mentions all efforts, but no mention of the AMCA.

Karan M · Post by **Karan M** » 20 Sep 2015 10:56

shiv wrote:This is the exact problem I have with the SDB - its pinpoint accuracy and low risk of collateral damage makes it suitable only for a niche role played by the Israeli Air Force against Palestinians and US air power versus Baghdad and Libya and its role against vehicles and single buildings in Afghanistan.

Shiv, heres how it may be useful in the Indian context. One of our high flying sats basically gets a radar map of x AFB. We decide on attacking it. The specific coordinates of multiple targets are mapped out, GPS/Lat/Long. A formation of Sukhois is decided for the task. On cataloging the targets and effort required, we realize one shot is what we get and there are several hundred targets that need to be hit. A Su-30 can carry only X large/medium LGB. Not all targets require 250 kg warheads and in any case, by using larger number of SDB type bombs with 100kg warheads, we can target multiple ones per target. Su-30s with a dozen pylons carry some 4 A2A missiles, 8 pylons with around 16 SDBs (http://www.copybook.com/military/news/b ... for-israel; Israelis 20/F-15). EW pods are on wingtips.
Similar variations:
So a "valhalla" sets out with Su-30s configured with ARMs and Kh-59s for SEAD/DEAD, with Su-30s with SDBs for mass attack and Su-30s with LGBs for higher/protected targets once AF defences are out. Another bunch of Su-30s provide air cover and EW. An overflying Heron does designation and BDA. Phalcon coordinates from afar including a battle with Pak AD to keep their fighters out of the strike area.
This the sort of maximisation we can benefit from, with effective bombs able to hit from 40-60 miles out (>SPADA effective range w/PAF). Smaller munitions? Even better, some An-32s get modified to carry another large bunch of SDB type munitions and disperse them in larger numbers.

We have been talking and reading so much about what the IAF has had to do and we are looking at putting airfields out of action, large areas where fuel, ammunition or vehicle concentrations are built up, factories with multiple buildings, refineries, electrical substations, railway marshalling yards, 3 km long tailbacks of vehicles taking supplies to the war front, 3/4 km long trains, a broad and deep front of attacking tanks across many sq km of territory, a 200 hut enemy camp hidden in the mountains like Muntho Dalo. In two wars, 1965 and 1971, the only "through the window" type of attack was on the Governor's bungalow in Dhaka shortly before the surrender. This sort of multiplicity of targets require plenty of explosive power and demand healthy collateral damage effects, which makes the SDB only a "little toe" in the limbs that constitute what the Air Force needs for attack. My problem is the way the name SDB keeps coming up as if it is going to make a huge difference. It is not.

You are right that SDB is only a useful tool in a box which requires many tools. Its key advantage (IMO) is volume and precision targeting for targets that are fragile (eg airframes) in known locations (eg AFB, factories etc). Our earlier approach of 100 dumb bombs on a target wont work anymore in an era of AD being more and more sophisticated. You get one chance and with limited airframes, we need to maximize number of shots/carrier platform. Earlier attacks we did are not that germane because we didn't have the tools then to do something similar, so we managed with what we had.

Once we get our own IIR/RF seeker production ramped up, we can do nifty things to address the range of scenarios. Americans can come out with a tool for any scenario since they have the basic building blocks ready, ditto for the Russians or Euros. We need to attain that matuirty.

My basic issue with taking the US SDB is that US just ahs to shut off the GPS or degrade it and all our investment goes Pfftttt...
So we have to develop our own.

shiv · Post by **shiv** » 20 Sep 2015 11:58

Karan M wrote: My basic issue with taking the US SDB is that US just ahs to shut off the GPS or degrade it and all our investment goes Pfftttt...
So we have to develop our own.

+1

I looked as deep as I could into the SDB issue during a recent discussion and was unable to get past the persistent reports that the American SDB in its current size and form (forget newer developments) was specifically developed to fit snugly into the F-22 and F-35s internal bays in a snug-fitting even number of rounds - ie the SDB dimensions and design were done keeping the F-22 and F-35 in mind. The fact that it can be carried in larger numbers on other aircraft is not a big deal, it is the "S" (as in small) of SD(s)B that was critical.

Unless the AMCA designers also have those same American internal bomb bay dimensions specs in mind, we need not be restricted by the particular design parameters of the US SD(s)B. It is, IMO the electronics that are more critical, not the explosive or ability to glide. If we can develop the electronics we can certainly develop a munition that is more versatile and less restricted than the SD(s)B

Karan M · Post by **Karan M** » 20 Sep 2015 12:36

Well AMCA bay dimensions will likely be as small/smaller than that of the F-22. Our overall aircraft is in the M category and internal volume is limited. SDB was probably initiated by small bay size issues of F-22 but once it prove/s useful, they'd extend it elsewhere, same as AESA on F-22 and then coming onto other platforms etc.

I hope the AMCA designers keep a wide range of munitions in mind not just SDB though. That sort of US centric thinking will be bad for us. We need flexibility to max. We need at least ARMs, LGBs all planned for.

NRao · Post by **NRao** » 20 Sep 2015 13:22

SDBs can be used for moving targets too.

All munitions are designed for particular purposes, this is no exception.

No idea what plans India has, but certainly India plans on developing sensors and there are efforts to miniaturization. Standoff is a given. So, the basic components are there. Even oven GPS. Is there a need? Dunno.

For what it is worth, came across 75kg FT-5 Chinese Small Diameter Bombs featuring 35kg warheads.".

Karan M · Post by **Karan M** » 20 Sep 2015 13:33

Any miss on a moving target is good as a mile.

shiv · Post by **shiv** » 20 Sep 2015 13:37

I think it should not be forgotten that the American SD(S)B is a glide weapon that has standoff ranges that are advertised as about 100 km. That would mean a waiting period of 10 minutes between designation of target, launch and hitting the target. This may be fine for a truck on an Afghan or Pakhtunkhwa road but totally useless for moving vehicles in an evolving battle scenario. Plus 9 kg explosive may be good for vehicles and hangars but it won't even take out a decent sized bridge despite the kinetic energy. Forget about runways.

shiv · Post by **shiv** » 20 Sep 2015 13:45

Karan M wrote:Any miss on a moving target is good as a mile.

Last I read the CEP remains 5 meters. That means 50% fall outside of 5 meters. Despite the claimed CEP of 1 meter.

NRao · Post by **NRao** » 20 Sep 2015 13:53

That is the challenge. How to improve all aspects. Cannot do it by cribbing about it. Need to take risks, IF one thinks such a product is needed.

How efficient are missiles like Nag? Can such tech not be used as a base?

Karan M · Post by **Karan M** » 20 Sep 2015 16:05

shiv wrote:I think it should not be forgotten that the American SD(S)B is a glide weapon that has standoff ranges that are advertised as about 100 km. That would mean a waiting period of 10 minutes between designation of target, launch and hitting the target. This may be fine for a truck on an Afghan or Pakhtunkhwa road but totally useless for moving vehicles in an evolving battle scenario. Plus 9 kg explosive may be good for vehicles and hangars but it won't even take out a decent sized bridge despite the kinetic energy. Forget about runways.

SDB has around 22 kg warhead with 17kg explosive, but we should at least try for warheads with 501-100 kg of explosive in our scenario.
http://www.defenseindustrydaily.com/ray ... ion-06510/
By limiting the warhead size, as you note, the dependence on a highly precise CEP increase manifold plus the need for all sorts of additional sensors.

http://www.ausairpower.net/APA-SDB.html

The glide wings provide a quoted delivery range of around 60 nautical miles for a high altitude release. The weapon performs a 180 degree roll post launch as the stowed configuration has the folded wings beneath the weapon.

The cited blast radius is 26 ft (cf 82 ft with 2,000-lb JDAM). Boeing claim the ability to penetrate more than 5 ft of steel reinforced concrete making the SDB I competitive against the BLU-109/B for many targets.

The SDB I will be most effective in the urban and broader close air support, battlefield interdiction, Destruction of Enemy Air Defences (DEAD) lethal suppression and counter-air strike airfield attack roles. Against soft skinned vehicles and structures, armour, point emplacements, runways, aircraft shelters and SAM/SPAAG systems this weapon will be highly lethal.

Where the SDB I will be less than effective is against deep / hardened bunkers, large infrastructure targets, large buildings, industrial plant, bridges, large trench systems, vehicle parks, infantry on the move and other area or large point targets. These remain the domain of larger specialised bunker busting weapons, or large explosive bombs such as the Mk.83/BLU-110 (1,000 lb), Mk.84/BLU-117/BLU-119 (2,000 lb), BLU-109/116/118 (2,000 lb), BLU-113/122 (5,000 lb).

The Raytheon GBU-53/B Small Diameter Bomb II is now in development, it will be equipped with a multimode terminal seeker and two way datalink, and is intended to enter full rate production in 2017. Intended production numbers in 2010 were 17,000 rounds, of which 12,000 are intended for the USAF, and 5,000 for the US Navy/Marines.

The design objectives for the GBU-53/B are quite different from those for the GBU-39/B. The GBU-39/B is a weapon optimised for fixed targets, especially hardened infrastructure and basing, whereas the GBU-53/B is intended for attacks on moving battlefield targets, especially vehicles and heavy armour. In the simplest of terms the GBU-53/B is a glidebomb equivalent to the AGM-65 Maverick missile, but with a more flexible and countermeasures resistant seeker.

The GBU-53/B guidance system combines seeker with a GPS/inertial autopilot, and a Rockwell Collins TacNet bidirectional dual band datalink, which provides JTIDS connectivity with aircraft and a UHF link with a ground designator. This is a refinement of the JTIDS based arrangement trialled for moving target engagements using the JDAM tailkit.

The tri-mode seeker employs semi-active laser homing, MMWI radar, and uncooled thermal imaging components to maximise flexibility in employment and counter-measures resistance. The semi-active laser mode permits the use of the SDB II with legacy airborne and ground based designators, against fixed and moving targets. The MMWI and thermal imaging modes permit autonomous fire-and-forget engagements, under a wide range of weather conditions, accepting that some fog and haze conditions will impair both thermal imaging and MMWI acquisition. The seeker optical dome is protected by a clamshell shroud which is jettisoned before the seeker is activated.

The warhead design is optimised for battlefield targets, parked aircraft, and unhardened structures, combining a shaped charge with blast/fragmentation effects. It will also be highly effective against unhardened and hardened air defence targets, such as SAM batteries, and maritime targets such as warships. A redesign of the warhead was performed during the development cycle to provide the capability to disable or kill main battle tanks.

In short, a very very complex design.

shiv · Post by **shiv** » 20 Sep 2015 16:46

Also :
Raytheon's Triumphant: Winning SDB II Innovation in action

First, we needed to shorten the weapon’s length in order to meet the government requirements to carry eight weapons in the Marine Corp’s Short Takeoff and Vertical Landing F-35B Joint Strike Fighter. Without reducing the weapon's length, the F-35B would be limited to six internal weapons, instead of the desired eight weapons.

see the comments..

brar_w · Post by **brar_w** » 20 Sep 2015 16:53

SDB has around 22 kg warhead with 17kg explosive, but we should at least try for warheads with 501-100 kg of explosive in our scenario.
http://www.defenseindustrydaily.com/ray ... ion-06510/
By limiting the warhead size, as you note, the dependence on a highly precise CEP increase manifold plus the need for all sorts of additional sensors.

http://www.ausairpower.net/APA-SDB.html

viewtopic.php?f=3&t=7088&p=1903280#p1903280

Also :
Raytheon's Triumphant: Winning SDB II Innovation in action

SDBII is primarily a CAS (among other missions) weapon for the F-35 and other strike fighters and that has largely driven its performance requirements.
The SDBII requirements were set in place at a time when the design had not completely sealed for the F-35B weight reduction. As the size of the F-35B weapons bay evolved from the A and the C both changes to it and some changes to the SDBII were sought to get the desired payload. The SDBII specific changes to the F-35B bays will happen later this decade and involve changing some plumbing inside the bay. The weapon's performance requirements have not changed since the concept was first floated to Boeing, and Raytheon.

The current SDB is also at times used for CAS especially when the fighter types need to support troops (through a JTAC) since that means they can provide more support with a higher payload. The USAF averages (the last decade) over 20,000 CAS sorties a year and as such when the SDBII comes online later this year or early next year it would provide a lot of capability for the F-15E particularly (because it has the loiter fuel-load) to hang around longer and provide bombs on target based on laser targeting by the troops or through a pod. Need define weapons requirements and the entire miniaturization trend with the SDB is not to replace a class of weapons but to create a new class of weapons that can handle certain mission sets that do not need higher payloads and where bigger bombs can be traded away for a greater bomb-load. CAS is one such area, DEAD is another. A radar set does not require a 1000 lb bomb and 4 smaller bombs may actually help overcome the defenses and even help in situations where there are decoys involved. The same technology on the SDB will ultimately be expanded to larger weapons in the future particularly as solutions are sought to the J-series replacement weapons, but that is a long term effort.

http://s11.postimg.org/rhkmrudbn/Screen ... _18_AM.png

Austin · Post by **Austin** » 20 Sep 2015 16:54

I think IAF/DRDO will have to work to gather to figure out what is the average warhead needed to take out most targets in our environment i.e Pakistan/China , taking into account factor like Hardened/Semi-Hardened base , most common military targets like airfield , C&C infra , Ammo Depo , Transport Infra etc , they need to take into account factors like CEP available for such weapon both in external aided guidance like GPS/GLONASS/GAGAN denied environment and factoring in average warhead size needed to take these out.

Now these might just be good for 60 % of the targets which might says 150 Kg warhead for guranteed destruction of target based on says INS Plus Some cheap Terminal homing system like EO/IR/TV/Semi-Active laser with CEP of 5-10 m then they can work on those types of weapons which meets our needs and within our ability to develop.

The remaining 15-20 % Target might just need 20-30 Kg type SDB warhead while the rest 20-25 might really need hard hitting 500/1000 Kg Weapon assuming similar CEP and indiginious guidance option available with India , ofcourse there would be the usual dumb bomb of 250/500/1000 Kg warhead relying on Aircraft INS/Radar guidance for delivery say with CEP of 15-20 m

These needs to be worked out between DRDO and IAF on what works best in Indian subcontinent based on type of targets we will encounter and based on available guidance method available during war to deliver these to the type of targets they need to be delivered too

srai · Post by **srai** » 20 Sep 2015 17:30

^^^
If Vayu Shakti are anything to go by, the IAF typically uses 1000lb in dive mode or CCIP for individual targets, like aircraft shelters. 250kg and 100kg are carried in multi-carriage and used for attacking an area, such as railway yards. PGMs (typically 1000lb LGB while other AGMs hardly seen) are few and so are used judiciously for high value targets.

Karan M · Post by **Karan M** » 20 Sep 2015 18:31

The basic thing is that without a huge funded effort for all sorts of guidance options, all these ambitions will go nowhere. We have multiple efforts underway, hope the new GOI funds them well, instead of merely relying on foreign vendors to do a Make In India.

NRao · Post by **NRao** » 20 Sep 2015 19:19

Between Austin and KM's post I gather India has not identified any need for a SDB. So far?

The first intro I could see on the US side was 1998. So, the US has been at it for about 15 years and are just about arriving at what they think they need.

I am making huge assumptions here, but seems to me India to even field a SDB is long way of. Even a US offer does not mean much at this point in time.

Making one in India, IMHO, the basic components are/seem to be there. Matter of writing the code, testing (testing and testing) - say one is 4-5 years out at best.

On the US side it is not there yet - it will get better, that is the purpose of a MIC.