[fhdowntheline]

On further research, I found this article about Tejas top speed limitation.

https://idrw.org/test-pilots-explain...-on-lca-tejas/

Would still like to know experts comments.

[shortbread]

Originally Posted by fhdowntheline

On further research, I found this article about Tejas top speed limitation.

https://idrw.org/test-pilots-explain...-on-lca-tejas/

Would still like to know experts comments.

I'm no expert but it holds in good stead especially taking into account what the adversaries have at their disposal.

The beauty of the Indian system is that information is transparent and we scrutinize failures and celebrate success with equal elan.

Say unlike our northern neighbors whose technical claims look impressive on paper but have a reputation of being underwhelming when put to the test. Eg. Nobody buys the J10 despite aggressive chinese marketing or the JF17's top speed is 1.6 Mach on paper, what it can achieve in real is the bigger question.

I don't think the Tejas was designed to win at Top Trumps, the role is far greater and after years of toil it's heading in the right direction.

[Theyota]

Back in the day when I was in college, I used to religiously follow up on the LCA program on “Bharat-Rakshak”. There were some interesting folks on that forum with very good insights. I found the below structural representation from one of those members in an email from 2004.




From what I understand from a very close source who provides electronic design and subsystem build services to various DRDO organizations, Navy is the only organization that has some level of understanding that for such a program to be successful, the end user is as much responsible as the supplier. Navy has over the years tried to build such technical capabilities within itself and therefore we have higher level of indigenization in Navy compared to Airforce.

A strong aerospace program results in the development of a very high level of intellectual capital in material science, electronics design and advanced precision manufacturing. If used properly, independent of the success of the aircraft itself, it can help other industries in creating millions of jobs.

[kvothe_rules]

This is a wonderful thread full of rich details. I remember seeing a model of the LCA on the desk of my Electronics professor in IIT Kharagpur and being totally mesmerized.

A question for the experts here- with improvements in UAV and drone technology, would the Tejas still be relevant say in the next 15 years? Its just something I was wondering about and would love for someone in the forum to shed light on

[RGK]

Highly informative thread and feel proud.

A general question from my side and it may be trivial.

Is it not risky to publish all the details (especially features & capabilities)about any military aircraft? Will it not provide sufficient information for other countries to prepare a successful counterattack plan in case of a conflict?

[DrPriyankT]

The Tejas to be honest does not need a really high maximum speed. If it were hypothetically to fly at Mach 1.6, it will be out of gas in 15-20 mins, as it will have to use it's afterburners. The Mig 21, was designed in an age when long range detection via air defence radars wasn't as accurate as it is today. So it was expected it would fly in at supersonic speeds to intercept the enemy aircraft, also it wasn't armed with long range missiles as the Tejas will be. The Tejas will be mainly positioned at frontline airbases, so it would not need to cover long distances to intercept enemy aircraft at the border, and also now we have the luxury of long range detection due to way more advanced radars, hence a high topspeed won't be necessary, especially for point defence interceptors like the Tejas


@RGK sir, all this information is from public domain, so please don't worry. :-)

[adityadeva]

A big thanks to Dr.Priyank for the excellent article and genuinely requesting him for the Kaveri engine thread - which would be a dream come true if they get it on Tejas.

I've seen that at a point Dr priyank was mentioning about criticism which he did not find valid. My take is that, defence purchase is a very corrupt business where several vested interests have a greater say.

There would be a number of articles with huge misleading headlines criticising the project. There's no doubt about the ulterior motives and paid promotions by vested interests.

Mastering a technology in defence is very very hard considering the above hurdles in addition to technological challenges. Privatisation of defence sector is going to be a big boon for many such projects

Also the fighter jet manufacturers would definitely be vary of a new entrant which will be cheaper to acquire and operate.

One thing is sure, the day Kaveri engine powers Tejas, no country would make an aircraft of its class for the price and lower maintenance costs as we can and that's the case so far and would be.

Centuries of getting ruled by external powers has just slowed us down, but that's nearing its end it seems

[JB_BLR]

Originally Posted by Theyota

From what I understand from a very close source who provides electronic design and subsystem build services to various DRDO organizations, Navy is the only organization that has some level of understanding that for such a program to be successful, the end user is as much responsible as the supplier. Navy has over the years tried to build such technical capabilities within itself and therefore we have higher level of indigenization in Navy compared to Airforce.
.

Indian Navy has always been the most ignore child amongst the three services hence they have the lowest allocation as well. To counter this they invested in their own research and development through Naval Design Bureau. Over the years they got good at it and you can see the results we have developed SSNs and an aircraft carrier.

Also as mentioned above there is lot of lobbying by foreign aircraft manufacturers to scuttle indigenous projects since it will take away their lucrative market. A very good example was when Sukhoi Checkmate was released and you could hear a lot of chatter how better it was and some people even mentioned to consider this over Tejas Mk2.
Another case in point being the JV with SAFRAN and Snecma where they were to integrate the M88 engine's core to Kaveri with some convoluted licensing terms that it seems DRDO will back out.
In these cases it is imperative that top brass of both military and political class support indigenous programs. Credit should go to our current IAF chief who has backed the Tejas program from the beginning.

[V.Narayan]

Originally Posted by fhdowntheline

Only one point that I would like to ask- how relevant would be the need for a Tejas to be able to reach speeds above Mach 1.6 (I understand that's the current limit) ?
Fighters in the similar size/role have slightly higher speeds, for example F16 can do M2.0, the Gripen can reach M2.0, I guess the Mig-21 itself is even slightly faster than that, even a F104 was faster.
Does this put any kind of disadvantage whatsoever on the Tejas on a comparative basis ?

Originally Posted by fhdowntheline

On further research, I found this article about Tejas top speed limitation.
https://idrw.org/test-pilots-explain...-on-lca-tejas/
Would still like to know experts comments.

Thank you for asking. I'm sure that is a question on the mind of aviation enthusiasts. Where speed in a fighter goes what really matters is your maximum speed and acceleration at sea level and at below 10,000 feet. Being able to fly at Mach 1.1 or better 1.2 at sea level is 10X more valuable than Mach 2.0 at 36,000 feet. Designers, the sensible ones, aim for speed and acceleration at low and very low altitudes. As a consequence of that power to weight, wing design etc you end up with some maximum speed at altitudes of 33,000 feet and above. That maximum high altitude speed is a result of what the designers are trying to achieve at low altitudes. In combat the maximum speed flying at high altitude would be a rare event when escaping or attacking from above while providing (for example) a high air cover/diversion in support of the real mission going on much lower. Frankly a speed north of Mach 1.6 or 1.7 is a waste. It requires specially designed inlets which add to the weight. In the 1950s to 70s it was assumed that fighters will engage with each other at Mach 2.0 at 40,000 feet. But Vietnam, Indo Pak wars and Israeli-Arab wars in the '60s and '70s showed that to be a non-starter. At 40,000 feet doing Mach 2.0 you are several times more vulnerable to Surface-to-Air Missiles than while doing Mach 0.9 at 500 feet. Hope this helps.

Originally Posted by RedTerrano

Envisaged in the 80's it took decades to enter service. How does this fare with other countries?

The short answer is very poorly. The real work did not start till the 1990s really so that is the real starting point.

Secondly, how does the existing Tejas tech fare with contemporary aircraft? Is that decades behind as well?

It stacks up very competently now. Certainly when compared to our two rogue neighbours. Our Air Force assets need to be comparable or better in quality to that of our adversaries. Journalists use the F-22 etc as a benchmark for comparisons which is simply not relevant or sensible.

Where do we go from here?

If the planners have any brains they should go one step at a time and build the Tejas Mk III first and put 15 squadrons in service. We need our numbers up desperately. Large numbers have a quality all of their own.

What stage will we stop becoming a weapons importer and transit to an exporter?

Never. Outside USA and Russia no other country designs and manufactures everything itself. We can get there only if like China we decide to spend 5% of our GDP on Defence and pour a significant part of our national resources into Defence indigenization for the next 40 years. Then we will get to maybe 80% self sufficiency. I am not sure that is a desirable aim given that where Govt budgets go we are rarely above water regardless of which party is in power.

Originally Posted by kvothe_rules

A question for the experts here- with improvements in UAV and drone technology, would the Tejas still be relevant say in the next 15 years? Its just something I was wondering about and would love for someone in the forum to shed light on

Excellent question and one that pops up often these days. Drones, manned aircrafts and missiles all have a role to play in the million combat situations that arise in a battlefield. These are complimentary to each other not replacements of each other. Drones have been in the news due to the American usage in Afghanistan and the recent war in Armenia. That does not make them a magic wand. In Afghanistan those drones were being operated against an enemy (Taliban) with zero, I repeat zero anti-aircraft(and drone) defences. In the face of even a moderately equipped enemy the effectiveness of drones could fall dramatically. Drones could work well in a situation where the two opponents are at vastly different levels of equipment and order of battle. Most drones are pilotless small low-observable helicopters. What is of concern is very small drones being used by the enemy to peep into the first 1 or 2 kms behind the border or front line of troops and using the reconnaissance data/photos to its advantage/terrorist activities. Hope this helps.

[whitewing]

Thanks to DrPriyankT for the wonderful compilation !

Originally Posted by V.Narayan

OT.
Sir, A query on the weight distribution and flight dynamics.
I got this doubt looking at the above schematic of weapon loading pods you had posted.
The non-static loads that the aircraft would carry are the fuel and armaments.

I'd read that (in commercial aircraft) fuel load imbalances are managed either manually or electronically. Since, this is a gradual reduction, I can (in a lay man's view) understand that a relative balance can be achieved via a set of sensors and pumps (ignoring the effects of fuel sloshing which would perhaps also causes imbalances?).

With regards to the weapons, say, a during a mission, a jet is armed with say, 2 bombs. On dropping a bomb, wouldn't the the weight distribution become lop sided?

How do these aircraft sustain speed and maneuverability with different load distribution scenarios?

[dragracer567]

Originally Posted by JB_BLR

Indian Navy has always been the most ignore child amongst the three services hence they have the lowest allocation as well. To counter this they invested in their own research and development through Naval Design Bureau. Over the years they got good at it and you can see the results we have developed SSNs and an aircraft carrier.

It is really interesting how there does seem to be a direct co-relation between how well-funded the arm of the military is to the levels of indigenization that arm has managed to achieve:

1) While the Army is the most well-funded of the three arms, it is still dependent on purchasing hundreds of Russian locally-made T-90s (now the Indian Army actually operate more T-90s than even the Russians) while the Arjun MK-1A which stands almost toe-to-toe with western tanks just got some courtesy orders for the DRDO's troubles. When it comes to guns, we've actually gone backwards by transitioning from the indigenous INSAS to foreign developed AK-103s & Sig 716s.

2) The Air Force has been a bit of a middle child, while it has also been addicted to expensive imports, it has still managed to achieve some levels of indigenization especially when it comes to helicopters while with the Tejas, there has been increasing confidence on their ability to design and build fighter jets as well. I hope after the C-95s are built in India, we will develop our own transport planes as well.

3) The Navy has been receiving the least resources despite the massive coastline and importance of India in the IOR named after itself (a virtue of having a land-locked Capital far from the coast, its easy to forget about the oceans while the two disputed borders with strong armies don't help). However, despite this (or rather because of this), the Navy has gone ahead and produced it's own Destroyers, Aircraft Carriers and SSBNs which are mind bogglingly complex machines (certainly more than guns which we still can't develop).

To conclude, despite what arm-chair military experts on YouTube say, throwing money at the armed forced won't fix it's woes. We already spend a fair proportion of our budget on the military at about 15% (+- 5%) which is more than most welfare schemes put together* (defense spending as % of budget is a much better indicator than % of GDP since the GDP is not the actual money that the government has in their hands to spend).

The answer to fixing the woes of our military is increasing the efficiency which is easier said than done as even the Americans are grappling with the same problem.

*Source: SG's cut the clutter, can't remember the episode

[RedTerrano]

Thank you Narayan Sir!
Happy and proud after reading your explanation.

Originally Posted by V.Narayan

Never. Outside USA and Russia no other country designs and manufactures everything itself. We can get there only if like China we decide to spend 5% of our GDP on Defence and pour a significant part of our national resources into Defence indigenization for the next 40 years. Then we will get to maybe 80% self sufficiency. I am not sure that is a desirable aim given that where Govt budgets go we are rarely above water regardless of which party is in power.

I don't understand why we need to design and manufacture ourselves to export. Perhaps license to manufacture and export can be worked out?

I can think of France and Sweden who export weapons. Am not sure if they do the designing and manufacturing themselves.

[reppy]

Aircraft speeds are now passé. What truly matters is lowest possible Radar Cross Section (RCS) and highest possible Beyond Visual Range (BVR) missile range.

The simple logic is to not be detected by the enemy and launch a long range missile in the process.

The combination of Tejas MK1A with a Meteor missile for air to air would be lethal!

[fulcrum29]

Originally Posted by V.Narayan

Thank you for asking. I'm sure that is a question on the mind of aviation enthusiasts. Where speed in a fighter goes what really matters is your maximum speed and acceleration at sea level and at below 10,000 feet. Being able to fly at Mach 1.1 or better 1.2 at sea level is 10X more valuable than Mach 2.0 at 36,000 feet. Designers, the sensible ones, aim for speed and acceleration at low and very low altitudes. As a consequence of that power to weight, wing design etc you end up with some maximum speed at altitudes of 33,000 feet and above. That maximum high altitude speed is a result of what the designers are trying to achieve at low altitudes. In combat the maximum speed flying at high altitude would be a rare event when escaping or attacking from above while providing (for example) a high air cover/diversion in support of the real mission going on much lower. Frankly a speed north of Mach 1.6 or 1.7 is a waste. It requires specially designed inlets which add to the weight. In the 1950s to 70s it was assumed that fighters will engage with each other at Mach 2.0 at 40,000 feet. But Vietnam, Indo Pak wars and Israeli-Arab wars in the '60s and '70s showed that to be a non-starter. At 40,000 feet doing Mach 2.0 you are several times more vulnerable to Surface-to-Air Missiles than while doing Mach 0.9 at 500 feet. Hope this helps.

I'm sorry sir but I disagree with your opinion here. Going mach 1.1-1.2 at low levels is not more valuable than going M>1.8 at higher levels. What your are saying was true till the advent of BVR combat. The aerial battle philosophy has moved away from low level/ high speed ingress and egress to medium to high level large number force projection. The modern aerial battlefield consists mainly of BVR scenarios.Won't disclose much, but a look at missile kinematics of modern BVRAAM's will tell you why high and supersonic missile launches give any fighter the edge over a slower and lower aircraft not at as high a mach number. What designers aim for at low levels is good low speed , high AOA performace because any a4m combat will naturally progress to lower levels as pilots try to keep their energy states high. Race to base is what it is called.There will hardly be any scenario where you will be going supersonic at low levels.
To answer whitewing, there are angle of attack and G limits which each aircraft has for each load configuration. Usually, asymmetric loads result in a reduced flight envelope. Modern fly by wire systems will automatically limit the aircraft to these limits. They will also trim off the excess stick pressures that the pilot may feel.

[warrioraks]

Originally Posted by DrPriyankT

This is my humble effort in describing the genesis of the LCA Tejas program in the IAF, it's capabilities and it's role in the future of the IAF. Be Warned, its a long read! I also request members to give their valuable opinions and more information which I may have missed to add.

Thank you for the amazing write-up. For me, LCA Tejas is the story of our designers, scientists, engineers. They have shown great perseverance in the face of extreme hardship - incessant ridicule, negative PR, lack of support from the end customer, embargoes, sanctions, budget constraints to count a few. Despite that, these sons and daughters of the soil have managed to deliver.
We should also not forget that India had designed and built another aircraft locally (HF Marut) in 1960s which was not considered very successful. Hence the knowledge to build an aircraft locally was either non-existent or obsolete by the time LCA project started. So practically this had to be to initiated groundsup and the entire eco-system had to be built from scratch. Everyone who has contributed to the program is a true unsung hero, utmost respects and reverences to them.

Originally Posted by RedTerrano

Envisaged in the 80's it took decades to enter service. How does this fare with other countries?

Narayan sir has answered your questions. Let me add a quick trivia on comparison with other fighter programs of the world. LCA Tejas has had zero crashes till date. This is no mean feat as we are talking about a timeframe spread across 3 decades as well as thousands of hours of test flight. This is usually unheard of when a country is developing a fighter plane. One more thing to be proud of!

Originally Posted by dragracer567

It is really interesting how there does seem to be a direct co-relation between how well-funded the arm of the military is to the levels of indigenization that arm has managed to achieve
.........
To conclude, despite what arm-chair military experts on YouTube say, throwing money at the armed forced won't fix it's woes. We already spend a fair proportion of our budget on the military at about 15% (+- 5%) which is more than most welfare schemes put together

Great points. Goes to show that - Necessity is the mother of all indeginization

Our defense allocation numbers although look high are just bare-minimum to sustain. Here is a quick breakup:
1. Salaries and pensions consume ~60% of total defense budget
2. Modernization and purchase of defense infrastructure - ONLY ~20% of the entire defense budget
3. The rest 20% is miscellaneous and other expenses

The financial situation we are in now, there is no alternate to indeginization and being efficient.

For anyone interested to know how the defense budget is spent, would recommend going through the link below. It was an eye opener for me - https://prsindia.org/budgets/parliam...alysis-defence