Tejas Mk2 Medium Weight Fighter: News & Discussion - 23 February 2019

[Rakesh]

Guys, please suggest the names to @hvtiaf on Twitter. Posting them here will have no effect. It just clutters up the thread.

Lost cause. Nobody is listening.

[Khalsa]

Let's finish cutting steel on the last FOC or the first Mk1a.
Then we can reenergize this naming intiative.

For now let's to continue to seed this thread with ideas that could enhance the capability of the Mk2.

[Prasad]

[VKumar]

Needs a virtual R2D2 to share the load

[rajsunder]

Needs a virtual R2D2 to share the load

I believe that we have that in the AI unit that interprets the speech and performs the tasks as required and also takes over in case the pilot is incapacitated.
The only thing is that it is included with the avionics and not a seperate robot that jumps in to the plane along with the pilot.

[kit]

Guys, please suggest the names to @hvtiaf on Twitter. Posting them here will have no effect. It just clutters up the thread.

Lost cause. Nobody is listening.

Have send the name suggestions ; AJAY, VAJRA, OJAS, AMOGHA,GARUN ..to @hvtiaf courtesy BRF

Any more please post away, i ll send it across . thanks

[Kartik]

There was a Twitter thread that HVT started where several names were suggested.

[Vamsee]

I personally wouldn't like any new name for MWF.
Tejas-1 (Will be upgraded to Tejas-2)
Tejas-2 (This should be the name for Mark 1A)
Tejas-3 (MWF)
Tejas-4 (AMCA)
Tejas-5 (TEDBF)

Similarly
Astra-1 (current Astra)
Astra-2 (Dual pulse)
Astra-3 (SFDR)

[kit]

Needs a virtual R2D2 to share the load

I believe that we have that in the AI unit that interprets the speech and performs the tasks as required and also takes over in case the pilot is incapacitated.
The only thing is that it is included with the avionics and not a seperate robot that jumps in to the plane along with the pilot.

virtual R2D2 = AI ., this will be very much a part of the software in some form or the other

[Rakesh]

https://twitter.com/HarshalPal5/status/ ... 49186?s=20 ---> Medium Weight Fighter (MWF) afterburning it's GE F-414 armed with following payload:

• 4 x Astra
• 2 x AIM-132
• 2 x Astra SFDR
• 2 x iDerby ER
• 1 x BrahMos

[Rakesh]

https://twitter.com/HarshalPal5/status/ ... 25765?s=20 ---> Indigenization! MWF being refueled by an RTA-90 aircraft.

[Khalsa]

baki to pata nahin
par sala Paint job .. Harish bhai ko dainee hai MWF kee

[JTull]

Fan-art! MWF will have retractable AAR probe, so won't be after-burning with it extended, not to mention the heavy load-out.

[Kartik]

https://twitter.com/HarshalPal5/status/ ... 49186?s=20 ---> Medium Weight Fighter (MWF) afterburning it's GE F-414 armed with following payload:

• 4 x Astra
• 2 x AIM-132
• 2 x Astra SFDR
• 2 x iDerby ER

There are mistakes in the rendering. The wing leading edge doesn’t join the fuselage that far up front. Seems like the fuselage plug is missed out. There shouldn’t be so much overlap between the canards and the wing leading edge. In this rendering it looks like a Tejas Mk1 with canards.

Harshal Pal is definitely trying hard but nowhere near as good as the rendering that Kuntal Biswas has done so far. His are near perfect renderings.

[Picklu]

Harshal Pal is definitely trying hard but nowhere near as good as the rendering that Kuntal Biswas has done so far. His are near perfect renderings.

Yup, Kuntal is the gold standard.

But Harshal also should be encouraged. The more the better. May their tribe prosper.

[Pratyush]

Harshal Pal is definitely trying hard but nowhere near as good as the rendering that Kuntal Biswas has done so far. His are near perfect renderings.

Yup, Kuntal is the gold standard.

But Harshal also should be encouraged. The more the better. May their tribe prosper.

Don't know how many of you remember the chini fakes of the early to mid 2000s, of the weapons programs. Those were all fiction. These have to be made real. As all are based on the authorised drawings published by DRDO.

[nachiket]

https://twitter.com/HarshalPal5/status/ ... 49186?s=20 ---> Medium Weight Fighter (MWF) afterburning it's GE F-414 armed with following payload:

• 4 x Astra
• 2 x AIM-132
• 2 x Astra SFDR
• 2 x iDerby ER

MWF will never fly with such a payload in actual combat conditions. The 3 different types of BVRAAMs aside, even in a pure air-defence config, at the very least the centerline hardpoint will carry a drop-tank. More likely, both inner wing HP's will carry drop tanks with the centerline HP empty or carrying a BVRAAM. The 2 other fuselage HP's might also be kept empty to keep the weight low and improve kinematic performance.

Except for the Su-30 we rarely see 4th gen aircraft fly actual sorties (or even training ones) without a single drop tank.

[Gyan]

I have always been intrigued by choice of Delta Wing for LCA MKI. Now we are going for even bigger delta wing on LCA MK2. There does not seem to be any clear advantage of using Delta wing except low wing loading as per my web surfing, reading. But what's the benefit of low wing loading if STR falls? Though there are some definite disadvantages.

On the other hand France had Delta wing for Mirage III, went to conventional wing for Mirage F1 and then reverted back to a big Delta wing for Mirage 2000.

So there had to be some clear benefits of Delta! Can someone more informed comment on this issue?

[Vips]

Do not want to go OT but thought may be relevant as the Tejas I and II have Delta wing.

Delta Wing Fighters: Rise, Fall and Comeback – Rafale, Gripen, Eurofighter Typhoon, Mirage etc.

[dipak]

ITBP to set up new posts on China border.

The government has allowed Indo-Tibetan Border Police to create 47 additional border outposts and 12 ‘staging camps’ to step up vigil along the border with China, officials familiar with the development told ET.
.
.
.
The border is not fully demarcated and the process of clarifying and confirming the LAC is in progress, officials said.

Why this news item in this thread ..?

[Gyan]

Do not want to go OT but thought may be relevant as the Tejas I and II have Delta wing.

Delta Wing Fighters: Rise, Fall and Comeback – Rafale, Gripen, Eurofighter Typhoon, Mirage etc.

Thanx for the link, though I had already seen it. Basically Delta wing was used in 1950-60s, followed by Swing wings & Conventional wings in 70s. Delta made a come back with Canards in 1980s. LCA MKIA designed in 80s does not have canards and it's a pretty big wing compared to other 1980s Canard Delta Configurations. But evidently delta would have some clear advantages as France went from conventional F1 to big delta ie Mirage 2000 & then to delta canard in Rafale.

On the other hand, even though delta Mirage 2000 came slightly after more conventional F16. But F16 has always been considered more versatile design, so question pops back again, why Delta?

Why LCA MKI did not adopt not F-16 type of wing with side intakes?

[Indranil]

On the other hand, even though delta Mirage 2000 came slightly after more conventional F16. But F16 has always been considered more versatile design, so question pops back again, why Delta?

CAn you explain how F-16 is considered more versatile. For example, the JF17 and the FA-50 are exactly of the configuration that you are speaking of. How are they more versatile than a Tejas, or vice versa?

[Indranil]

On the other hand, even though delta Mirage 2000 came slightly after more conventional F16. But F16 has always been considered more versatile design, so question pops back again, why Delta?

What is the definition of more versatile? For example, how is a JF17 or FA-50 more versatile than an LCA, or vice versa?

[fanne]

If you really be bookish about it, there is not match up between Mig 21 and F-22 to declare one is better than other (and no explanation is enough if I can keep questioning...there is no end to this debate).
The Turkish F-16 and M2K of Greece keeps tangling with claims and counterclaims. IAF and PAF, where there could be another flash point, there has not been any matchup (even the Feb 27 one was between Mirage3/5/jf-17 and M2K, and F-16 and 30mki).
But more countries have imported F-16 than M2K (one can also attribute to lower cost and more cheaper weapons and US clout) than m2k. It could be argued, almost all countries that bought F-16 could have bought m2k, but instead went for F-16 (if that is a proof for its versatility).
Given, all this, I would agree - F-16 is more versatile than M2K (and perhaps more capable). Otherwise so many of them would have not been made and so many follow on versions made. Even when they have been costlier than m2k, countries have bought F-16 than M2k.
Then we can always get into theoretical argument about ITR (M2K) and STR (f-16) which is good and bad, TWR (F-16 miles ahead). None of us here are fighter pilots with research experience in Air to air tactics and data and experience to back the theory (the point to note, there is no data, the universe has not yet produced an event where m2k and f-16 went against each other even once, and you would need a decent sample to make an announcement which is more versatile or better).
Ps - I am using versatile interchangeably with capable which may not be the intent of the OP

[Indranil]

I think we are confusing way too many things.

- Aerodynamic efficiency is only one of the aspects of versatility. And versatility is one of the aspects of sales.
- You seem to be suggesting that F-16 is aerodynamically a better A2A platform than Mirage 2000. In this too, you seem to be matching the EM diagrams when you speak of matching ITRs/STRs etc. Even in this oversimplification, may I ask you the question. What would the E/M diagram of Mirage 2000 look like if it were powered by an engine like the F-16s?

The question is if a designer with enough maturity in 1980s was given an engine and asked to design an airframe around it, what config will he/she chose if stealth and reuse were not considerations. That answer is quite obvious from all over Europe and China. Even in the US, people trying to optimize the F16 reached the XL config. BAck in India, LCA designers did not have the maturity in 1980s. They wanted to keep it simple first. Just like Dassault wanted to when it designed the Mirage 2000. LCA's EM diagram is classified, but from all accounts it is very similar to the Mirage 2000s. Today, when they have the maturity, they are going for the MWF. That last mile that they can gain with the canard config.

[Gyan]

I have always been perplexed by the big complicated wing chosen by the LCA designers. There does not seem to be any obvious reason for it especially in view of the fact that LCA MKI does not match Mirage 2000 performance. LCA MK-2 = MWF was a good opportunity to simply the wing or even make it smaller but we seem to have gone for even bigger wing. Now, AMCA wing is completely different. Therefore evidently ADA is going for more conventional layout (Quasi delta?) with AMCA.

On the other hand, to give data contrary to my own view:-

http://www.mirage-jet.com/COMPAR_1/compar_1.htm

[nachiket]

I have always been perplexed by the big complicated wing chosen by the LCA designers. There does not seem to be any obvious reason for it especially in view of the fact that LCA MKI does not match Mirage 2000 performance.

LCA Mk1 was never supposed to match M2k performance! It was supposed to be a replacement for the Mig-21, including fitting into the existing Mig-21 aircraft shelters on our bases. Hence it is smaller, lighter and has a smaller and less powerful engine than the M2k. How and why would it match M2k performance? BTW, performance here means payload and range. It might match/exceed M2k on other parameters. Its avionics are definitely better than the original M2k and match what is on the current upgraded Mirage-2000I. As for kinematic performance, we do not know how the two compare but I suspect they are close.

Aircraft are designed to requirements. LCA Mk1 requirements were NOT the same as the requirements laid out when the M2k was designed by the French or even when it was acquired by the IAF. M2k was considered a "Medium" category aircraft by the IAF as late as early 2000's when they wanted to buy 126 more of them.

[Indranil]

I have always been perplexed by the big complicated wing chosen by the LCA designers. There does not seem to be any obvious reason for it especially in view of the fact that LCA MKI does not match Mirage 2000 performance. LCA MK-2 = MWF was a good opportunity to simply the wing or even make it smaller but we seem to have gone for even bigger wing. Now, AMCA wing is completely different. Therefore evidently ADA is going for more conventional layout (Quasi delta?) with AMCA.

On the other hand, to give data contrary to my own view:-

http://www.mirage-jet.com/COMPAR_1/compar_1.htm

Do you know what aspects of the Mirage 2000 performance the LCA Mk1 doesn't match? Is the size of the wing related to that?

What is a Quasi delta wing? AMCA conventional layout is because of stealth requirements.

I think you should throw that idea from your mind that the conventional layout is more "versatile"!

[titash]

I have always been perplexed by the big complicated wing chosen by the LCA designers. There does not seem to be any obvious reason for it especially in view of the fact that LCA MKI does not match Mirage 2000 performance. LCA MK-2 = MWF was a good opportunity to simply the wing or even make it smaller but we seem to have gone for even bigger wing. Now, AMCA wing is completely different. Therefore evidently ADA is going for more conventional layout (Quasi delta?) with AMCA.

On the other hand, to give data contrary to my own view:-

http://www.mirage-jet.com/COMPAR_1/compar_1.htm

Do you know what aspects of the Mirage 2000 performance the LCA Mk1 doesn't match? Is the size of the wing related to that?

What is a Quasi delta wing? AMCA conventional layout is because of stealth requirements.

I think you should throw that idea from your mind that the conventional layout is more "versatile"!

The versatility of a weapons platform depends on:
1) the mission profiles it can carry out
2) the endurance it has to carry out those missions
3) the sensor/weapons package that guarantee mission effectiveness

For #1, the Tejas has shown it is an effective MiG-21 replacement; a small footprint low cost locally supported fighter that can carry out routine interceptions, QRA alerts, and local air defence. It goes above and beyond the MiG-21 in being able to assume the self-escorting iron-bomb/PGM delivery role...something only the Su-30 and Mirage 2000 could do earlier. The engine F404 is not the highest performance engine out there but among the 3 engine parameters of cost, reliability, performance it scores very well in cost & reliability...this ensures pilot confidence and safe low-cost competency building

For #2, the Tejas being *designed* as a small fighter cannot assume the DPSA/Interdictor roles of the Su-24/34, F-15E, Tornado. Likewise it cannot maintain long duration CAPs unlike the Su-30 and F-15C. Air-to-air refueling can solve some of these issues but not to a very large degree of effectiveness. The F-16 and Mirage 2000 being volumetrically larger are better at this role

For #3, the Tejas is king. The sensor/weapons architecture is ours and can be changed at will. Likewise as India moves towards maturity in airborne radars like UTTAM, airborne weapons like ASTRA/NGARM/SAAW/BRAHMOS-NG and EW suites like DR-118 Dhruti/D-29, our capability in this regard will go up exponentially. This is only matched by the Su-30 because we own the source codes and avionics to some degree

[Gyan]

Indranil, I am just trying to understand the logic behind LCA design and why is it being carried over into MK2. Evidently same wing design even though considered for MCA in 1990s is not being carried over into AMCA. While China has used Canard Delta for its Stealth fighter.

F-16XL was supposed to have poor low altitude performance, and in any case its wing is somewhat different from LCA.

Inspite of being way better in this area, you just raised 3 questions in your last post without giving any input.

Why does LCA MKI (supposedly) have shorter range than Mirage 2000, inspite of having better fuel fraction?

[Indranil]

Gyan,

AMCA is not aerodynamically more efficient or more versatile than MWF. Actually, AMCA pays the price of aerodynamic efficiency to gain stealth. The loss in efficiency is being overcome using brute power. By the way, it is not all about the the layout. For example, AMCA designers can design more effective control surfaces, but that would compromise on RCS. And every 5th generation design team has chosen a balance of RCS vs aerodynamic optimization. The J-20 designers wanted a long range fighter bomber. Therefore, their aircraft is pretty big. Yet, there is a limit to the engine capacity. So they had to chose a design point which is more aerodynamically efficient. Hence the canard-delta layout. That's compromise on RCS.

Who told you that LCA MK1 has better fuel fraction over Mirage 2000? LCA Mk1 has a fuel fraction of 0.25. Mirage 2000 has a fuel fraction of about 0.30. Actually, LCA's range with DTs is not significantly less than Mirage 2000. But the biggest problem for LCA Tejas is that its external fuel tanks are not optimized. I have written extensively on this. You will see those tanks come in with MWF.

The Mirage 2000 is the 5th or 6th generation of the aircraft in the Mirage family. That has tremendous effect on its optimizations. I mean look at the Mirage2000, there is not one abrupt edge on that plane. You have to see the plane from close to realize how beautiful it is. Every curve on that plane (except for the strake on the inlets) is a piece of art. For people who don't understand how refined the Mirage 2000 should speak to a designer. A tailless pure delta that can fly at 100 knots! That's is mind boggling. By the way, LCA is not too far behind. It has been test flown at 105 knots. Squadron pilots cannot fly at that speed. The FC won't let it to build in buffer.

MWF is the second generation of the LCA family will be more efficient the Mirage 2000. It has got nothing to do with us having better designers. They stand on the shoulders of the generation of designers that designed the Mirage 2000.

[nam]

Is it worth while to consider a design, where a minimal(or no) internal fuel tank, but only CFT(large as required).

This will allow you to create a very aero refined design and add a large CFT as well.

[Indranil]

I did not answer the question of why the LCA wing is being carried over to MWF. LCA's wing is really good and very well understood by its designers. They also know its shortcomings. So although you see MWF taking the wing in general, you can see the tweaks to overcome its weaknesses. The canard is a huge change. Won't go into that in this message. But, do you see the wing join. It is different. You can find why in Nilesh's and my write up for DDR. Do you see the wingtips. They did not do that to just add a weapon station. They found it to provide better L/D. They actually added the 4th weapon station under the wing because they have now found that the wing is structurally sound enough to carry that load. Again an optimization. Did you notice the leading edge extensions. There are two instead of three. Once again that's an optimization to reduce weight and complexity.

The initial AMCA design was actually for a non stealth medium weight fighter. LCA's wing would not have worked for that MCA as well. People gave out artists impressions. But think about it. LCA's wings are either optimized for LCA or MCA, but cannot be for both at the same time!

[Indranil]

Is it worth while to consider a design, where a minimal(or no) internal fuel tank, but only CFT(large as required).

This will allow you to create a very aero refined design and add a large CFT as well.

I cannot make sense of that. Why would you design an aircraft with CFTs (and small internal tank) from the get go? I can understand it for something like TEDBF where the goal is to keep design effort to the minimum from an existing solution, i.e. MWF. But frankly, I expect ADA to use a body plug rather than a CFT.

[nam]

Is it worth while to consider a design, where a minimal(or no) internal fuel tank, but only CFT(large as required).

This will allow you to create a very aero refined design and add a large CFT as well.

I cannot make sense of that. Why would you design an aircraft with CFTs (and small internal tank) from the get go? I can understand it for something like TEDBF where the goal is to keep design effort to the minimum from an existing solution, i.e. MWF. But frankly, I expect ADA to use a body plug rather than a CFT.

My question was about a general design, like as you mentioned TEDBF/ORCA. I was curious to know, if such a design would make sense.

[nachiket]

Why would you waste the space inside the fuselage and wings?

[nam]

Why would you waste the space inside the fuselage and wings?

Well you don't. Inside of having fuel tanks, you place lrus. Specially in the fuselage.

There might be space in wings, where you cannot place kit. Those can be filled with fuel. However even in case of wings, it would be more useful to have less fuel, to able to carry more stores.

[Gyan]

Indranil, thx for reply. I will read and try to understand what you said. You should also have a look at the link which I posted above. The data in the link help support some of your arguments

[Indranil]

Thanks Gyan.

That link is basically a readout of the EPS diagrams of the three aircrafts. Tejas EPS is confidential. But based on the Bahrain show you can infer some things. ITR of Tejas is better than Mirage. Minimum radius is also shorter. STR of Tejas is in between that of Mirage and F16. But, there is room for improvement on Tejas Mk1's STR. Wingtip pylons for example would have helped. I don't know the corner speed of Tejas. Mirage 2000's transonic acceleration is better than Tejas. Here, the refinements play a part. The solutions are known and it is a pity that Mk1As won't have them. The intake and splitter plate can be redesigned. Similarly, the area behind the cockpit and the engine bay door can be reshaped for better area ruling.

Loiter time of Tejas with two 1200 ltr tanks is over 2 hours. Mirage's loiter time is better.

[Indranil]

Why would you waste the space inside the fuselage and wings?

Well you don't. Inside of having fuel tanks, you place lrus. Specially in the fuselage.

There might be space in wings, where you cannot place kit. Those can be filled with fuel. However even in case of wings, it would be more useful to have less fuel, to able to carry more stores.

CFTs are not ideal. from drag or RCS perspective. So, you will never see a clean sheet design with CFTs. They are a good compromise when you are upgrading an existing platform.