AMCA - Advanced Medium Combat Aircraft (HAL)

[Decklander]

If you clarify whethe you can fly a conventional plane after the loss of all hydraulic fluids I will also clarify.

RSS ac with pure delta design of any combination has more problems than solutions. It is for this reason that F-22 and F-35 both have tailplane. Typhoon and Rafale have Canards. To sustain high AOA you need control input even in RSS ac as it might just do a flip. But in a pure delta RSS ac, it requires abnormally high control inputs. The high AOA of F-16 & F-18 is due to vortices generated by LERX and in F-35 by the chin and this ability has nothing to do with RSS.
The cranked delta design only provided solution to poor slow speed handling of delta designs and nothing else. The planform of YF-23 and F-22, F-35 is called Trapezoidal design and not a delta design. The lightest, strongest and max volume wing form is a trapezoidal planform. It also has far lower drag as has been proven by the excellent kinematic performance of these wings. The effective sweep angle of a trapezoidal wing is the algebric sum of its back and fwd sweep. YF-23 was far superior to F-22 as it had a wing which was swept fwd and back at same angle of 40* giving it an effective sweep angle of zero like a straight wing while still having all the benefits of a sweepback wing.
The mach cone is a well defined for each speed and the problem of keeping wings can be overcome in many more simpler ways than using delta design like reducing the span, AR, Increasing the length of the nose, placing wings well aft etc.
In fact, A NASA study had found that lightest fighter can be made which uses trapezoidal wing in a tailless design and not delta planform. I have not been able to locate that file as many NASA files have been removed from net after the chinese cyber activities.

 

[Decklander]

If you clarify whethe you can fly a conventional plane after the loss of all hydraulic fluids I will also clarify.

An RSS delta design ac must make use of elevons thruout its flight while being negatively stable which adds much higher drag to it than a conventional stable desig or a canard design. It also has problem in its roll rates for this very reason. A cranked delta has excellent gust riding qualities but poor dogfighting ability as the vortices add to drag and larger the sweep angle of a delta, larger is the drag which you too have agreed. This requires higher power settings to sustain turns so whatever ITR advantage RSS gave you by way of higher pitch up is undone by the poor STR which results for the same reason.
Reagrding ac being able to fly without hyd power, B-737-1/2/3/4/5/6/7/8/9 have complete manual reversion and can be flown by just the muscle power of a pilot. I have over 2500 hrs on them in command. all fighters flown by IAF barring Mig-29, Su-30MKI, M2k have hydro-mechanical controls and can be flown with speed restrictions down to zero speed. They all can do dead stick landing. I have flown Hunters which also had this feature. But in case of a failure of FBW, pilots have no option but to eject as ac departs. We have already lost three fully fit Su-30s due to FBW malfunction, two Gripen prototypes were lost and many such cases keep happening all over the world with RSS FBW ac.

 

[ersakthivel]

RSS ac with pure delta design of any combination has more problems than solutions. It is for this reason that F-22 and F-35 both have tailplane. Typhoon and Rafale have Canards. To sustain high AOA you need control input even in RSS ac as it might just do a flip. But in a pure delta RSS ac, it requires abnormally high control inputs. The high AOA of F-16 & F-18 is due to vortices generated by LERX and in F-35 by the chin and this ability has nothing to do with RSS.

for your information trapezoidal and cranked delta are one and the same.Not really different to each other in the aerodynamic layout.The F-22 and F-35 both are much larger planes , so they need tail planes. In tejas by having bigger after wing control surfaces the same is achieved.

Every one knows that having tail planes just after the huge wings reduce their efficiency by a large margin as a result of wing wash on the tail planes.

canards or LREX or also does the same job of crank in the delta, that is producing lift inducing stall delaying energizing vortices. Nothing more. nothing less.

A canard was added to Tejas and tested in wing tunnel and found out to give so significant efficiency increase for the weight and power penalty it provides.

Also if you see the canard deltas the control surfaces like elevons attached to the wing are small for (ex- Grippen ) compared to tejas.
So in the sum totl all it matters is having sufficient area on control surfaces. that's all.

canard config also has the undesirable element of canard tip wash on the wing and lead to pilot induced oscilations leading to crash in certain circumstances.Also the charecteristics of large aspect canards and the peculiarities of their charecteristics must be taken into account.

Wings are also deprived of fresh air laminar undisturbed stream in many flight profiles of the canard delta config imposing significant limitations on canard operations.And the inevitable canard wash over the wing reduces the wing's aerodynamic effficiency in certain critical flight profiles.

But on the other hand the cranked delta performs as part of the wing eliminating all the above mentioned complexities and at the same time providing the lift inducing vortices ensuring fresh airstream for high wing efficiency all the times.

diamond , trapedoizal, cranked delta may be different in geometrical sense but their aerodynamic purpose are all the same i.e generate vortices give better lift to drag ratio enhance low speed specs, ensure high alpha high AOA performance at corner speeds. thats all.

The cranked delta design only provided solution to poor slow speed handling of delta designs and nothing else. The planform of YF-23 and F-22, F-35 is called Trapezoidal design and not a delta design. The lightest, strongest and max volume wing form is a trapezoidal planform. It also has far lower drag as has been proven by the excellent kinematic performance of these wings.

As I said earlier trapezoidal,crank , or compound delta a;; serve the same purpose, they may look different in geometry but aerodynamically they do the same job of vortice generation.

They do not produce lower drag . All of them produce better lift to drag ratio countering the higher drag of plain delta wing form
.

The effective sweep angle of a trapezoidal wing is the algebric sum of its back and fwd sweep. YF-23 was far superior to F-22 as it had a wing which was swept fwd and back at same angle of 40* giving it an effective sweep angle of zero like a straight wing while still having all the benefits of a sweepback wing.

These algebras will be taken care of in design phase in any cranked delta fighter aimed at providing the best combination for the weight , wing loading and ASR req of the fighter. SO there is no need to discuss that.The shock cone of YF-23is much larger than the Tejas , so you can place that kind of wing form and still have low enough wing loading along with tail planes due to the bigger plane the YF-23 was compared to LCA TEJAS.

The mach cone is a well defined for each speed and the problem of keeping wings can be overcome in many more simpler ways than using delta design like reducing the span, AR, Increasing the length of the nose, placing wings well aft etc.

The mach cone is also well defined for the size of the fighter dictating optimum wing shape suited to it like Trapezoidal or cranked delta.

In fact, A NASA study had found that lightest fighter can be made which uses trapezoidal wing in a tailless design and not delta planform. I have not been able to locate that file as many NASA files have been removed from net after the chinese cyber activities.

So nothing really changes wrt to canards or cranks or trapezoidal wing form as all the variation of the pure deltas are aimed at vortice generation to energize the wing and nothing more..

 

[ersakthivel]

An RSS delta design ac must make use of elevons thruout its flight while being negatively stable which adds much higher drag to it than a conventional stable desig or a canard design.

It is to counter this undesirable property of pure delta form the cranked delta is used to provide better lift to drag ratio energizing the wing and reducing trim drag effort.The higher natural lift of the low wing loading added with energizing cranked delta can take care of that.

It also has problem in its roll rates for this very reason. A cranked delta has excellent gust riding qualities but poor dogfighting ability as the vortices add to drag

VORTICES ON THE CRANKED DELTA WING FORM,INCREASE LIFT TO PROVIDE BETTER LIFT TO DRAG RATIO AND CANCELLING OUT THE INHERENT DRAG OF THE PLAIN DELTA WING FORM,which forms the basis of best dog fighting skills.
Where in the world do you find vortices increasing drag!!!!!!!!!!! they reduce it in fact by providing better lift to drag ratio in cranked delta tailess fighters.

and larger the sweep angle of a delta, larger is the drag which you too have agreed.

tHE SWEEP ANGLES ARE OPTIMIZED FOR LESSER DRAG TRANSSONIC FLIGHT UNDERTAKEN BY CRANKED DELTAS MOST OF THE TIME. WHERE DID I AGREE LARGER SWEEP ANGLE MEANS LARGER DRAG?

This requires higher power settings to sustain turns so whatever ITR advantage RSS gave you by way of higher pitch up is undone by the poor STR which results for the same reason.

WHAT IS MORE IMPORTANT IN TODAYS COMBAT IS ITR AND BETTER NOSE POINTING ABILITY TO FIRE HIGH OFFBORESIGNT HMDS -DASH WVR MISSILES, NOT STR. I HAVE POSTED IT MORE THAN HUNDRED TIMES.

Reagrding ac being able to fly without hyd power, B-737-1/2/3/4/5/6/7/8/9 have complete manual reversion and can be flown by just the muscle power of a pilot. I have over 2500 hrs on them in command. all fighters flown by IAF barring Mig-29, Su-30MKI, M2k have hydro-mechanical controls and can be flown with speed restrictions down to zero speed. They all can do dead stick landing. I have flown Hunters which also had this feature. But in case of a failure of FBW, pilots have no option but to eject as ac departs. We have already lost three fully fit Su-30s due to FBW malfunction, two Gripen prototypes were lost and many such cases keep happening all over the world with RSS FBW ac.

The age of all electrical control is dawning.And you are talking of piloting a few old IAF planes being flown by pilot's muscle power!!!!!
No one is going to make fighters like that any more.

 

[arnabmit]

As AMCA is put on the backburner (I do believe the reports as India just loves to postpone & delay anything and everything) the question is:

Is India planning on only PMF as a counter both J-20 & J-31?

 

[ersakthivel]

As AMCA is put on the backburner (I do believe the reports as India just loves to postpone & delay anything and everything) the question is:

Is India planning on only PMF as a counter both J-20 & J-31?

AMCA is not put on back burner the reports stating stuff like that are regular fakes circulating all over the media , that will be refuted by official statements , once in a whule.

Since such fake reports about LCA and AMCA are regularly doing rounds ADA or HAl or MOD are not going to dignify them with official denials.

it has been stated in ADA website that once ADA contemplated issuing a full page ad in national news reports refuting these fake sob stories , but concluded it is a waste of time and money.

FGFA, RAFALE and AMCA are all different projects aimed at addressing different needs of the country's airspace security at different time intervals.

Any talk of one supplanting another as stated in the article you quote is simply dumb writing and is not credible

 

[lookieloo]

Yes, there is a F-22 replacement program. It is still in the early stages of RFI where feasibility studies will be conducted. Boeing is already conducting one for the SH replacement. Sure, we will need to wait for official confirmation, but,

https://www.fbo.gov/index?s=opportu...0c9c983f85e7952c2adc426b189&tab=core&_cview=1

The feasibility studies are ongoing.

Google "Miss February aircraft" and that will give you an idea. You can say we are in the early 80s when you compare to the F-22's development where companies are still doing feasibility studies and project definition, meaning USAF will have to wait for at least half a decade more before a RFP can be made.

Nothing more than a paper technology study and some Lockheed concept art... and nothing remotely close to a *next generation* fighter program. As I already told you, F/A-XX or NGAD (or whatever you want to call it) is just a USN program that's generated some pretty pictures of potential SUPERHORNET replacements; and an actual program to replace the F-22 in the 2030s would have tangible hardware under construction by now with contractors selected for a flyoff. I suppose fanboys will still be fanboys, but you are all going to be disappointed.

Navy May Buy More F-35s, Not Fewer, Under F/A-XX Initiative « Breaking Defense

Now, I suppose someone here is gonna tell me how India is going to do much better. Go ahead, I'd love to hear it.

 

[lookieloo]

don't you find it odd that in AMCA forum people are dragging LCA needlessly?

To be honest, I'd hardly noticed before you hijacked the thread. It's only natural that everyone would discuss ways for a new fighter program to avoid past mistakes. Tough beans if you consider that to be "needless dragging." Again, I don't really care one way or another about LCA; it is what it is, but it isn't the focus of this thread. Let it go dude.

 

[aerokan]

AMCA is not put on back burner the reports stating stuff like that are regular fakes circulating all over the media , that will be refuted by official statements , once in a whule.

Since such fake reports about LCA and AMCA are regularly doing rounds ADA or HAl or MOD are not going to dignify them with official denials.

it has been stated in ADA website that once ADA contemplated issuing a full page ad in national news reports refuting these fake sob stories , but concluded it is a waste of time and money.

FGFA, RAFALE and AMCA are all different projects aimed at addressing different needs of the country's airspace security at different time intervals.

Any talk of one supplanting another as stated in the article you quote is simply dumb writing and is not credible

Well..it's about time they start these malicious reports on AMCA.. They are running out of stories to create on LCA. AMCA will keep their imaginations run wild for another couple of decades and pay for their food.

 

[ersakthivel]

To be honest, I'd hardly noticed before you hijacked the thread. It's only natural that everyone would discuss ways for a new fighter program to avoid past mistakes. Tough beans if you consider that to be "needless dragging." Again, I don't really care one way or another about LCA; it is what it is, but it isn't the focus of this thread. Let it go dude.

So you are saying that you haven't noticed posts by decklander criticizing LCA needlessly in this thread. Anyway i have no arguments with that.

See I have shifted all the posts pertaining to my debate with Decklander related to the LCA , to LCA mk-2 thread.

So you are free to carry on posts with AMCA without worrying who is a good MOD , who is a pit bully,and who is needlessly dragging LCA here and I won't be hijacking AMCA thread anymore.

 

[ersakthivel]

Well..it's about time they start these malicious reports on AMCA.. They are running out of stories to create on LCA. AMCA will keep their imaginations run wild for another couple of decades and pay for their food.

it is a common trade practice to plant stories hurting rivals in business. Nothing more. Unless official news confirms it no use discussing these no official named, speculation based reports seriously.

 

[p2prada]

Nothing more than a paper technology study and some Lockheed concept art... and nothing remotely close to a *next generation* fighter program. As I already told you, F/A-XX or NGAD (or whatever you want to call it) is just a USN program that's generated some pretty pictures of potential SUPERHORNET replacements; and an actual program to replace the F-22 in the 2030s would have tangible hardware under construction by now with contractors selected for a flyoff. I suppose fanboys will still be fanboys, but you are all going to be disappointed.

Navy May Buy More F-35s, Not Fewer, Under F/A-XX Initiative « Breaking Defense

Now, I suppose someone here is gonna tell me how India is going to do much better. Go ahead, I'd love to hear it.

If you read closely, it talks of the program being unaffordable.

As of today USAF has only one fighter development program, we have two, possibly 3 in time. This when our economy is only 1/7th yours.

So yeah, we can do better.

Anyway, F-22 started as a concept diagram too, back in the 80s.

If you actually believe you won;t have a replacement program then you don't know anything about your own country.

 

[lookieloo]

As of today USAF has only one fighter development program, we have two, possibly 3 in time. This when our economy is only 1/7th yours.

So yeah, we can do better.

Tell me more about these three *Indian* programs (must have actual hardware flying to count).

 

[p2prada]

Tell me more about these three *Indian* programs (must have actual hardware flying to count).

Sure, FGFA, LCA and a possible AMCA. All running simultaneously. Of course, I have not included other aerospace programs which even the US already has or will have.

PAKFA and LCA prototypes are already flying.

The question is affordability (as mentioned in the article you posted), and as a development program PAKFA is Russian, but our money is involved. Hence, Indian. PAKFA alone equals F-22s scale of work, maybe more because of the higher requirements in electronics which exceeds even the F-35's requirements. So funding demands will be equally large in scale.

As for AMCA, it heavily depends on the numbers expected to be produced and the specs required. It is too early to talk about it, but we know that the project and the requirement exists.

Also, in 2030, the article says that the F-35 will be the only fighter produced in 2030 in the US, but in India's case, we may have two, maybe 3 if we expect Rafale to be inducted in similar numbers as MKI.

 

[lookieloo]

^^^completely ignored the criteria of my request^^^

 

[Decklander]

The age of all electrical control is dawning.And you are talking of piloting a few old IAF planes being flown by pilot's muscle power!!!!!
No one is going to make fighters like that any more.

F-15 till date is non FBW conventional design with Hydromechanical controls. And F-15 has the highest number of A2A kills in modern times.
Hunter maybe an old ac but I have also flown Sea Harrier and FYI, B737-8/9 and A-320 are still top of the line commercial ac and I have tons of exp on them also.
regarding, electrical controls, The Power-by-wire and use of EHSA started only with F-22 & F-35. The so called future will return to Hydro mechanical system as it has been found that the kind of weight savings promised by these electrical systems has actually not delivered and they are prone to failures and over heating.
Regarding your famous, outstanding, only real fighter, best of the best F-16XL, you have failed to answer as to why no ac has ever been built with the similar wingform. The development of EFT & Rafale started when F-16XL had already flown but even they did not use the so called revolutionary CRANKED DELTA design.

 

[ersakthivel]

F-15 till date is non FBW conventional design with Hydromechanical controls. And F-15 has the highest number of A2A kills in modern times.
Hunter maybe an old ac but I have also flown Sea Harrier and FYI, B737-8/9 and A-320 are still top of the line commercial ac and I have tons of exp on them also.
regarding, electrical controls, The Power-by-wire and use of EHSA started only with F-22 & F-35. The so called future will return to Hydro mechanical system as it has been found that the kind of weight savings promised by these electrical systems has actually not delivered and they are prone to failures and over heating.
Regarding your famous, outstanding, only real fighter, best of the best F-16XL, you have failed to answer as to why no ac has ever been built with the similar wingform. The development of EFT & Rafale started when F-16XL had already flown but even they did not use the so called revolutionary CRANKED DELTA design.

F-15 is old history, It's STR and ITR are abysmally low compared to even Tejas , Grippen,TYPHOON, RAFALE.

All the glorified kills of F-15 were achieved against very small rudimentary airforce's of third worl dictator with next to nothing EW capability decades back against older MIG-29 s of soviet block with long range BVR kills , when the Mig-29s were not even aware of them being fired on.

So these fancy kill ratios have no relevance in RSS tail less delta discussions.

Well for your information CANARDS are not the new world beating discovery of the european delta canard makers, It was present from the days of WRIGHT BROTHERS first flight as a pitch control device , unaffected by the wing wash like tail planes.

If you look at the size of the control surfaces attached to grippen's wing and the size of the same in tejas , it is quite clear than bigger more powerful control surfaces of Tejas compensates for the canard pitch control action.

That was proved by ADA in a wind tunnel test for the tejas aerodynamic layout which proved for the weight and drag , power penalty imposed by canards it gave no significant advantage in performance for the specific aerodynamic layout of Tejas.Simply put the larger wing of TEJAS with cranked delta produces the same vortex effect of CANARDS leading to beneficial lift to drag ratio as proved in F-16 XL and the larger wing attached control surfaces gave enough maneuverability for the tejas design in particular.


You may ask then why this could not be found out by SAAb?

The answer is SAAB went with canrds based on their design skills in Viggen. And sorted out the problems with canards.


And ADA went with what was proved by F-16 XL with bigger cranked delta wing- no canard layout , and bigger control surfaces attached to wings.

In the recently concluded airshow even within the 6G restrictions tejas mk-1 LSP-7 completed a vertical loop in 20 seconds.Which translates to 18 deg STR same as that of more powerfull twin engined f-15 and comparable to delta -canard grippen's 20 DEg with fully relaxed flight envelope with much higher AOA of around 28 Degand 9G limits.

So the difference between the Tejas mk-1 and Grippen C/D is not very much .Considering tejas mk-1 achieved 18 deg STR with far lower AOA limitations of 22 deg and restricted 6Gs.Meanwhile the much powerful F-15 has an STR of just 15 to 18 deg, which is at about 70 percent of the Tejas mk-1 and grippen capability.

It is obvious that once 300 KG telemetry equipment in Tejas mk-1-LSP-7 is removed and it's Gs are relaxed to 8G , it can easily come close to the grippen's loop time of around 18 seconds i.e ( an STR of 20 Deg per second)even without canards.It can
be achieved once spin test are over and AOA is relaxed to 24-- 26 deg and Gs relaxed to 8 from the present 6 in FOC.

If you want a comparison of tejas with grippen NG then you have to wait for tejas MK-2 .

F-15 had more powerful radars and longer range bigger air to air missiles and more power to avionics due to twin engines which were the preconditions for the ASR issued for it.SO the selection of F-15 has nothing to do with the efficiency of F-16 XL's cranked delta wing form as it had a single engine, lesser range , and less power for avionics,

If you want to discuss the matter further please post in LCA tejas-IV thread as that thread is dedicated to disccussion on RSS- cranked delta tailless airframe.

AMCA does not belong to that airframe design as it is a much bigger fighter with different ASR requirements. So other posters here are objecting to discussing LCA here.

 

[bhramos]

Indian 'Home-Grown' AMCA, An Alternative To FGFA | Aviation International News

 

[WMD]

Official information on the AMCA at Aero India 2013 was limited to a one-page leaflet with three views and key marketing terms, such as net-centric warfare, vehicle management (including weapons), data fusion, decision aids, integrated modular avionics, internal carriage of weapons, signature control with sharpening for low observability, AESA radar, IR search-and-track, supersonic persistence, high-speed weapon release and thrust vectoring. It was stated that the aircraft would be able to "swing roles" variously between long/short-range and air-to-air/ground strike.

According to press reports, scientist Dr. A.K. Ghosh heads the AMCA development effort. Some observers have suggested that, unlike the FGFA, the AMCA's primary role will be ground attack, and so it will be a direct replacement to the MiG-27M and the Jaguar. Also, there are reports about a "revolutionary" pilot station employing a panoramic active-matrix display (or displays) with touch-screen interface and voice commands, and a helmet-mounted sight replacing, rather than supplementing, a head-up display.

The AMCA is likely to be an "electronically" actuated airplane rather than hydraulically operated. Instead of the digital flight-control computer, as used on the Tejas, the AMCA is to have a distributed processing system employing fast processors and smart subsystems that can pass over and combine the processing power available in them. This requires the employment of the IEEE-1394B-STD rather than MIL-STD-1553B databus standard. The new airplane is also planned to have a "central computational system connected internally and externally on an optic-fiber channel by means of a multiport connectivity switching modules." Also mentioned are fly-by-light, electro-optic architecture with fiberoptic links for signal and data communications.

Indian 'Home-Grown' AMCA, An Alternative To FGFA | Aviation International News

 

[A chauhan]

AMCA to be developed in 12-15 years

Published July 10, 2013 | By admin
SOURCE: SP's Special Correspondent

While the DRDO puts its full weight behind priority delivery of the LCA Tejas to the Indian Air Force (IAF), its new Chief Dr Avinash Chander has made an ambitious claim: that the stealth fifth generation advanced medium combat aircraft (AMCA) will be delivered in 12-15 years. The AMCA, while not a formally sanctioned project yet, is still on the drawing board in the conceptual phase, and will receive formal funding only once deliveries begin of the FOC LCA Tejas Mk.1.

The DRDO is currently working on several enabling technologies, including stealth, vectored thrust nozzles, serpentine air intakes, internal weapons bays, advanced avionics, etc to form the foundations of the advanced aircraft. The aircraft will be larger and more powerful than the Indo-Russian PMF/FGFA, and will be a priority stealth strike platform for operations behind enemy air defences. Current research and development on the project is being funded through internal resources, and work will pick up in earnest from late 2014 when the burden of the LCA Tejas is off the DRDO's shoulders. A degree of foreign consultancy will be inevitable on the AMCA, sources indicate.

AMCA to be developed in 12-15 years | idrw.org