AMCA News and Discussions

brar_w · Post by **brar_w** » 16 Apr 2018 14:55

With 2 x GE-F414 the margins would be rather tight when it comes to weight, drag and thrust required to obtain useful supercruise. It is certainly possible but they will have to hit very strict targets when it comes to those. Keep in mind that on 5th generation aircraft, the bay, RCS considerations and internal sensors provide a drag penalty compared to clean 4th generation aircraft like the Typhoon. This is obviously reversed when you load up the 4th gen aircraft with fuel and bombs but it remains so in clean configuration.

JayS · Post by **JayS** » 16 Apr 2018 15:29

^^ Right. F135 gives about 125kN dry thrust while 2xF414 would give ~115kN. AMCA is lighter by about ~1.5T empty weight. Given F35 cannot supercruise in a practical sense, AMCA is also unlikely to do so. But with 115-120kN class engine, things will become interesting for AMCA.

I have not found any source indicating what is the increase in Dry thrust for the F414 EE version, assuming that will be fitted eventually on AMCA. In the current form F414 is rather inadequate in both dry and wet thrusts for AMCA. Maybe OK to start with, but not for entire life and/or if weight creep happens like LCA in initial stages itself. ADA want 2x110kN engines for AMCA precisely to avoid these situations.

brar_w · Post by **brar_w** » 16 Apr 2018 15:33

That was what I was getting at as well. There was a good reason that the F-22, F-35 and the SU-57 went on to develop dedicated next-generation engines. While the enhancements to the F414 will increase its overall thrust, the jury is still out that if and when they are actually funded, how much enhancement is seen in the dry thrust department.

JayS · Post by **JayS** » 16 Apr 2018 15:37

brar_w wrote:That was what I was getting at as well. There was a good reason that the F-22, F-35 and the SU-57 went on to develop dedicated next-generation engines. While the enhancements to the F414 will increase its overall thrust, the jury is still out that if and when they are actually funded, how much enhancement is seen in the dry thrust department.

Only spec I have seen so far is claimed hike in TET of 64K. This can be used to either bump up the life or the thrust.

arshyam · Post by **arshyam** » 16 Apr 2018 20:12

Kartik wrote:Does anyone have an image of AMCA at DefExpo 2018 from the side and top profile as well?

Do these help?

AMCA-1 by arshyam, on Flickr

AMCA-2 by arshyam, on Flickr

AMCA-3 by arshyam, on Flickr

vina · Post by **vina** » 16 Apr 2018 20:58

brar_w wrote:That was what I was getting at as well. There was a good reason that the F-22, F-35 and the SU-57 went on to develop dedicated next-generation engines. While the enhancements to the F414 will increase its overall thrust, the jury is still out that if and when they are actually funded, how much enhancement is seen in the dry thrust department.

One thing I got out of analysis the Kaveri engine and it's thermodynamics and design cycle in detail is about how soon the thrust lapses with altitude and high ambient conditions (think high speed dash at low levels) for jet engines, especially for high compression ratio engines. The YF-120 engine from GE in the F-22 contest was a variable cycle engine (in many ways similar to the Kaveri ,difference being that the YF-120 actually varied the bypass ratio) and switched between a high bypass for take off and climb and subsonic conditions and switched to low bypass for super cruise conditions. That it lost out to the F-119 which is a conventional cycle engine is a different matter.

GE has repurposed the YF-120 as the "ADVENT" engine, which again is variable bypass engine, but the optimisation being more towards fuel economy in the subsonic cruise conditions (possibly for range performance), rather than outright super cruise performance.

For the AMCA, if super cruise is a requirement , then they will actually need custom low bypass engines to be developed. If it uses the existing F414 or similar , all those are actually great for subsonic cruise and dashes to supersonic on reheat, but really don't cut the mustard otherwise. The AMCA will need around around 120 KN dry thrust. But with the thrust lapse with altitude and at high ambient conditions inherent in the GE F414 (the larger fan and higher bypass dont really help here), and the EJ200 and M-88 derivatives, how much thrust will be available in altitude and will that be sufficient is an open question.

Austin · Post by **Austin** » 16 Apr 2018 21:36

IIRC we had a discussion here eons back where some one entioned of large wetted surface area ( boxy fuselage ) of AMCA design would add to drag and that too would impact supercruise

prasannasimha · Post by **prasannasimha** » 16 Apr 2018 21:38

I don't think these are the latest models. I have seen these in Adamya Chethana last year. . I think you will not see the exact final model for obvious reasons

Philip · Post by **Philip** » 16 Apr 2018 21:52

This is what I find curious.The IAF insist on super-cruise for the FGFA and only a " new engine" will do, but are quite happy - if the data given is right, to accept a non-super C engine for the AMCA which is not exactly the latest from the West. When this bird will enter service by around 2030, and that's a tight timeframe too, an entire decade of new aircraft design, development and delivery would've taken place.Unless this bird possesses a level of tech superior to the 5th-gen birds of today, we would've merely attempted to reinvent the wheel a decade late as is being displayed with the LCA, touted as a mini M2K, an aircraft no longer in production!

This is why industry experts keep on harping about the engine selection for the AMCA, the most important decision.We've already had two experiences of inadequate engines with the HF-24 and the LCA, though some might say that with the latter it is the obesity of the bird that is the problem not the engine.

Kartik · Post by **Kartik** » 16 Apr 2018 22:41

Cybaru wrote: So are you saying we are already pushing for roughly 8000 kgs of fuel? minus the weight of pilot and some stuff (200 kgs)

Cybaru,

JayS already mentioned that the F-22's specs are the ones shown below

Loaded weight = 29400 kg
Empty weight = 19700kg
MTOW = 38000kg
Internal fuel = 8200 kg
Length = 18.92 m
Wingspan = 13.56 m
height = 5.08 m

With an empty weight of 19700 kg, it can manage 8200 kg of internal fuel. that is a fuel fraction of 0.42.

Now with a target empty weight of 12,000 kg for the AMCA, how will it be possible to get anywhere near 8000 kgs of fuel?

Expect ~5400 kgs of fuel internally for the AMCA, even if they improve on that fuel fraction and get it to 0.45

Kartik · Post by **Kartik** » 16 Apr 2018 22:43

Could someone please post a pic of the AMCA specs sheet at DefExpo 2018?

Kartik · Post by **Kartik** » 16 Apr 2018 22:51

arshyam wrote:
Kartik wrote:Does anyone have an image of AMCA at DefExpo 2018 from the side and top profile as well?
Do these help?

yes they do thanks Arshyam. Do you have better pics of the second model, with the external stores? It has the planform that is more representative of the diagram included in ADA's EOI document.

Kartik · Post by **Kartik** » 16 Apr 2018 22:59

JayS wrote:^^ Right. F135 gives about 125kN dry thrust while 2xF414 would give ~115kN. AMCA is lighter by about ~1.5T empty weight. Given F35 cannot supercruise in a practical sense, AMCA is also unlikely to do so. But with 115-120kN class engine, things will become interesting for AMCA.

I have not found any source indicating what is the increase in Dry thrust for the F414 EE version, assuming that will be fitted eventually on AMCA. In the current form F414 is rather inadequate in both dry and wet thrusts for AMCA. Maybe OK to start with, but not for entire life and/or if weight creep happens like LCA in initial stages itself. ADA want 2x110kN engines for AMCA precisely to avoid these situations.

From AW&St

The upgrade supports an increasingly aggressive Boeing campaign that aims to continue F/A-18 production for the Navy in response to delays in Lockheed Martin’s F-35C program.

GE has been carrying out design and test work for some years on improved F414s, but has been offering two options: a more efficient and more durable engine (the enhanced durability engine, or EDE) and an Enhanced Performance Engine (EPE) with up to 20% more power in both intermediate and maximum thrust. Now GE and Boeing have decided to offer a single configuration that will deliver either EDE or EPE characteristics with a software switch, with EPE to be used in wartime.

The new engine will shorten the F/A-18’s transonic acceleration time from 72 to 50 sec. (carrying up to four Amraam missiles in the Advanced Hornet’s centerline weapon pod) while reducing fuel burn and maintenance costs at the standard thrust setting. It would be available from 2018, which is also the planned service-entry date for the F414-powered Saab JAS 39E.

brar_w · Post by **brar_w** » 16 Apr 2018 23:08

All those GE enhancements have been well discussed here, but the point stands that none of that work is currently funded to completion. The USN in its Block III Shornet road-map chose not to pick up engine enhancements, choosing instead to buy more aircraft. South Korea has picked the F414 but have not yet disclosed that they intend on funding any enhancements that add thrust. The Franco-German project, if it goes anywhere, is looking at a 2040 timeframe and none of the US future designs will require this thrust class, which means that outside of a customer funding it they have to rely on 4.5 generation aircraft programs for funding enhanced engines and they too are unlikely to need such dramatic thrust increases.

Kartik · Post by **Kartik** » 16 Apr 2018 23:28

As more data becomes available, it appears that the AMCA and the KF-X will look like close cousins. Similar engines, twin that too, twin tails, with a cockpit canopy that seems more like the F-35 design than the F-22. The AMCA is slightly longer and narrower with a smaller wingspan and flatter, with a smaller height. Approximate target empty weights are within 1 metric ton of each other.

the AMCA will hence need the additional thrust, both dry and wet, more than the KF-X, being targeted as a 12 metric ton empty weight fighter.

KF-X

Indranil · Post by **Indranil** » 16 Apr 2018 23:37

These AMCA models mean nothing more than cost saving in making new display models for the show.

Kartik wrote:
KF-X

Wow! That is a good looking plane!

Cybaru · Post by **Cybaru** » 16 Apr 2018 23:39

Kartik wrote:
Cybaru wrote: So are you saying we are already pushing for roughly 8000 kgs of fuel? minus the weight of pilot and some stuff (200 kgs)
Cybaru,

JayS already mentioned that the F-22's specs are the ones shown below

Loaded weight = 29400 kg
Empty weight = 19700kg
MTOW = 38000kg
Internal fuel = 8200 kg
Length = 18.92 m
Wingspan = 13.56 m
height = 5.08 m

With an empty weight of 19700 kg, it can manage 8200 kg of internal fuel. that is a fuel fraction of 0.42.

Now with a target empty weight of 12,000 kg for the AMCA, how will it be possible to get anywhere near 8000 kgs of fuel?

Expect ~5400 kgs of fuel internally for the AMCA, even if they improve on that fuel fraction and get it to 0.45

The specs for f35A are as follows:
Internal fuel capacity: 18,498 lb (8,382 kg)
Empty weight: 28,999 lb[477] (13,154 kg)
FF = 0.64

Su-57
Fuel capacity: 10,300 kg (22,700 lb)
Empty weight: 18,000 kg (39,680 lb)
FF = 0.57

J-20 (Just for FF calculations)
Fuel capacity: 11,340 kg (25,000 lb) internally
Empty weight: 19,391 kg (42,750 lb)
FF=0.58

Rafale (Non stealthy calculations are different but just for sake of comparison)
Empty Weight: 10,300 kilograms (22,700 lb) (B)[69][263]
Fuel capacity: 4,700 kg (10,400 lb) internal
FF=0.45

I do think that the FF will be closer to .6 rather than .4, which roughly puts it closer to 7200 kgs (8136-9576 depending on temp)

Kartik · Post by **Kartik** » 17 Apr 2018 00:17

Posting some relevant images from an article that dates to October 2017 on the KF-X.

Now for someone to do some such research on the AMCA. Hopefully not most of the usual suspects posing as defence journos in India.

Source: AW&ST

IR, if you want the entire article, please share your email ID.

Will · Post by **Will** » 17 Apr 2018 00:55

JayS wrote:^^ Right. F135 gives about 125kN dry thrust while 2xF414 would give ~115kN. AMCA is lighter by about ~1.5T empty weight. Given F35 cannot supercruise in a practical sense, AMCA is also unlikely to do so. But with 115-120kN class engine, things will become interesting for AMCA.

I have not found any source indicating what is the increase in Dry thrust for the F414 EE version, assuming that will be fitted eventually on AMCA. In the current form F414 is rather inadequate in both dry and wet thrusts for AMCA. Maybe OK to start with, but not for entire life and/or if weight creep happens like LCA in initial stages itself. ADA want 2x110kN engines for AMCA precisely to avoid these situations.

I think this is where the rumoured engine development with Rolls Royce might come into play. I hope it’s true. Without supercruise,speciallly in the 2040 time frame,which is when the AMCA is expected to be out in numbers, it is not going to be a true 5th gen aircraft.

Kartik · Post by **Kartik** » 17 Apr 2018 02:03

Kartik wrote:Could someone please post a pic of the AMCA specs sheet at DefExpo 2018?

nevermind. Found it on Saurav Jha's twitter page

G limits:+8G/-3.5G- same as the Tejas Mk1 whereas Mk2 was to be a 9G/-3.5G fighter.

Philip · Post by **Philip** » 17 Apr 2018 04:33

I wonder about the two large tailfins.They look a trifle too large and not canted enough to reduce rcs as seen in other stealth birds.Have they been finalised after WT testing or as said in an above post, old models to avoid extra costs.

Cybaru · Post by **Cybaru** » 17 Apr 2018 05:35

how does height of a plane make a difference? if it were 4.6 vs 4.2 what would be different perhaps other than clearance?

Indranil · Post by **Indranil** » 17 Apr 2018 07:10

Kartik,

indranilr@ gmard kaum.

That AMCA poster is bogus. That is my problem with ADA/DRDO. They don’t even proof read their posters/materials. They don’t care. They don’t think that this matters. The RFI has the right numbers.

JayS · Post by **JayS** » 17 Apr 2018 09:02

The numbers could be for one of the displayed configs. However they are quite close to actual numbers from EOI. Thus the weight numbers must be also in the correct ballpark.

I wonder why the EOI has given some of the figures like fuselage volume and other such seemingly unnecessary data. But from the numbers it looks like the Wing volume is 5.6m3 or in the ballpark. That itself puts internal fuel in the wings close to 5000ltr give or take some. I think 7000-8000kg internal fuel is feasible.

Katare · Post by **Katare** » 17 Apr 2018 13:50

The DRDO Chief clearly stated that F414 is a starting engine for the AMCA development. He said like LCA and Gripen started with F404 and moved up to F414, when time comes AMCA will graduate to a bigger and newer design engine but right now I need something proven and adequate to start my development work.

In 10-15 years when we are making AMCA mk2 we’ll have a suppacrooze engine for it.

JayS · Post by **JayS** » 17 Apr 2018 15:48

Rafale used F404 for its TDs.

Kartik · Post by **Kartik** » 17 Apr 2018 23:13

Indranil wrote:Kartik,

indranilr@ gmard kaum.

That AMCA poster is bogus. That is my problem with ADA/DRDO. They don’t even proof read their posters/materials. They don’t care. They don’t think that this matters. The RFI has the right numbers.

IR, is that CAD model of the AMCA the actual final configuration? Because there are significant differences in the vertical fin design between what is shown in that model and what is there in the EOI document.

nrshah · Post by **nrshah** » 17 Apr 2018 23:22

Philip wrote:This is what I find curious.The IAF insist on super-cruise for the FGFA and only a " new engine" will do, but are quite happy - if the data given is right, to accept a non-super C engine for the AMCA which is not exactly the latest from the West. When this bird will enter service by around 2030, and that's a tight timeframe too, an entire decade of new aircraft design, development and delivery would've taken place.Unless this bird possesses a level of tech superior to the 5th-gen birds of today, we would've merely attempted to reinvent the wheel a decade late as is being displayed with the LCA, touted as a mini M2K, an aircraft no longer in production!

This is why industry experts keep on harping about the engine selection for the AMCA, the most important decision.We've already had two experiences of inadequate engines with the HF-24 and the LCA, though some might say that with the latter it is the obesity of the bird that is the problem not the engine.

Sir, this is what I am happy. IAF supporting domestic product more than imported. And why be curious, IA is doing reverse for T90 in comparison to Arjun. Why not raise it there??

Indranil · Post by **Indranil** » 17 Apr 2018 23:51

Kartik,

The picture in the EOI looks like that of 3B-09, which is the config which they finalized after PDR AFAIK.

Kartik · Post by **Kartik** » 18 Apr 2018 00:25

None of the images of the configurations from 3B-01 to 3B-09 they had supposedly studied had these kind of vertical fins. Which is why the doubt as to what is the final configuration they've settled on.

And this image was in ADA's Annual report. See the vertical fins here.

This FEM model was from some other report

And this from some presentation

Kartik · Post by **Kartik** » 18 Apr 2018 00:33

And this was the latest AMCA FEM model from the NAL Directors Report 2016-17. it is just like the model shown in the EOI. the vertical fins are like those of 3B-09, not like the CAD image in the poster at DefExpo 2018. So it really seems that ADA/DRDO whoever came up with that poster didn't even bother to check if the model was accurate or not.

CSIR-NAL has made significant contributions to the ADA’s national progarmme on Advanced Medium Combat Aircraft (AMCA). NAL provided extensive support to structural design and development. The studies in the third phase of AMCA were focused on the design and analysis of airframe using AMCA 3B-09 version model. The design team carried out optimization studies on wing and its control surfaces for strength and buckling constraints.
Preliminary dynamic, flutter analysis and design of forward retraction main landing gear were carried out in the reporting period. (Fig. . This
year the full-scale air intake duct of AMCA was handed over to ADA.

sankum · Post by **sankum** » 18 Apr 2018 01:13

Option 1. If the clean take off weight of AMCA @20000Kg from the poster includes internal payload.

Then empty weight=12000Kg

Internal fuel=5500Kg est

Internal payload=2000Kg est.

Rest=500 kg(pilot, cannon ammo, 4nos internal weapons launcher)

With external payload of 5000 Kg,

MTOW = 25000Kg.

Option 2. If the clean take off weight of AMCA @20000Kg from the poster doesnot include internal payload.

Then internal fuel is 7500kg est.

And MTOW=27000 Kg est for 2000 kg internal payload and 5000 kg external payload.

I think the first option is most likely.

BTW S Jha has once commented about internal payload being raised to 3000 Kg.

Indranil · Post by **Indranil** » 19 Apr 2018 07:34

Kartik,

You have hit the nail on the head. They don't care to get the posters right. They did hire a company for a year or two and may be at the verge of losing their services.

That poster is inaccurate, just like LCA posters of yore. The NAL drawing, EOI etc. are accurate.

SaiK · Post by **SaiK** » 05 May 2018 10:39

Here’s The F-22 Production Restart Study The USAF Has Kept Secret For Over A Year.

http://www.thedrive.com/the-war-zone/20 ... ver-a-year

I'm x-posting for contextual reference

SaiK · Post by **SaiK** » 17 May 2018 09:41

Yet another interesting article that might be having referential.value here

The YF-23's Air Inlet Design Was Its Most Exotic Feature You Never Heard Of

http://www.thedrive.com/the-war-zone/20 ... r-heard-of

JayS · Post by **JayS** » 17 May 2018 13:01

^^Nice. Thanks for posting. Only thing I think the author has wrongly equated holes on splitter plates on fighters like EF2000 with those on YF23. The holes in many fighters on the front portion of the inlet are more for inlet shock position manipulation rather than large scale BL control.

Need to check bit more technical paper or report on why the YF23 uses those holes for. tiny holes don't look like they enough to suck significant amount of BL air unless there is a strong active control system with pumps doing the work. But the article says its passive system and I am bit skeptical about it.

PS: I checked some hi-res images. Its a mesh, perhaps covering a cavity which has opening on the top side of the wing. Not a porous media as I thought initially.

jaysimha · Post by **jaysimha** » 18 May 2018 12:17

There is a requirement for a consultatnt in the dept. of AMCA, ADA with following QRs in qualification and experience
https://www.ada.gov.in/currentdocs/consultantAMCA.pdf

Vips · Post by **Vips** » 18 May 2018 18:45

Tamil Nadu to build India’s next generation defence aircraft.

The Aeronautical Development Agency, which had conceived and designed the Light Combat Aircraft (LCA) Tejas, has set the ball rolling for building the next generation defence aircraft, the Advanced Medium Combat Aircraft (AMCA), by extending an invitation to private players in Coimbatore to build a technology demonstrator.

The proposal is not only the first time an indigenous military aircraft programme is seeing the involvement of private players, but it is also the first time a defence plane development project is proposed to be executed outside Bengaluru.

The project — to be implemented in Sulur in Coimbatore district which may house the permanent base of the Tejas squadron — marks Tamil Nadu’s first major defence aircraft project.

Talking about the fifth generation aircraft that may eventually replace Tejas, ADA programme director Girish Deodhar said: “We’ve only invited an Expression of Interest and received application from a few industries. It’d be too early to reveal names or numbers as the project is in a preliminary phase and final clearance is awaited.”

The agency, created for the design and development of Tejas, has become relevant with the AMCA project and defence sources said the involvement of private players is in line with the Centre’s ‘Make In India’ programme and it could help with the project’s timelines.

“There’s a proposal to implement the project in Sulur and the decision is based on the fact that Bengaluru has no space for technology development. The HAL airport already has too much testing. We looked at Chitradurga but it was not feasible because there was a problem with the approach part of the field. Since Sulur has an airfield, it looks good,” Deodhar said.

According to ADA, private players will be required to manufacture, assemble and equip two fighter aircraft and for the first time the industry will be involved from the stage of developing a process plan, design and fabricate parts, manufacture both metallic and composite parts, prepare sub-assembly jigs, create subassemblies and transport them to the identified Flight Test Facility.

Rakesh · Post by **Rakesh** » 25 May 2018 05:33

https://twitter.com/indiandefence11/sta ... 0096417792 ---> Here is DRDO developed Ultra Wide Band (ULB) Radar Absorbing Skin Prototypes which will be used for Indian Stealth Aircrafts like AMCA and AURA.

Austin · Post by **Austin** » 29 May 2018 10:47

Integration Analysis of Conceptual Design and Stealth-Aerodynamic Characteristics of Combat Aircraft

www.scielo.br/pdf/jatm/v8n1/1984-9648-jatm-8-1-0040.pdf