Tejas Mk.1 & Mk.1A: News & Discussions: 23 February 2019

Cybaru · Post by **Cybaru** » 28 Sep 2019 09:51

Dileep wrote:Heat removal is the number one problem in AESA. It was some jubilation when Uttam could finally fit everything into the Tejas budget.

LRDE is preparing to make LSP builds now, as per chaiwale.

It won????

Raghunathgb · Post by **Raghunathgb** » 28 Sep 2019 10:21

Dileep wrote: LRDE is preparing to make LSP builds now, as per chaiwale.

LSP even before user trails? Or are they increasing number of prototypes for faster testing?

srai · Post by **srai** » 28 Sep 2019 10:28

^^^
You have to do things concurrently and iteratively to shorten the time from design, test, integrate, test, production. If you wait for one step to “finish” before starting the next step, it will end up as long drawn out affair i.e. “delays”.

JayS · Post by **JayS** » 28 Sep 2019 11:34

srai wrote:^^^
Is this 450L tank new addition?

Then there is a 710L supersonic tanks as well.

450L supersonic tank is been there for a while now. 710L is optimised version. From the DDR Article on LCA,

Similarly, computation fluid dynamics (CFD) studies on a variety of drop tanks have yielded fuel tank geometries which could carry more fuel at marginal to no extra cost in drag. For example, Figure 5 shows the modified supersonic drop tank arrived by choosing optimal lengths for the conical nose and tail sections. The final shape allowed the carriage of 58 percent more fuel (710 L against the current 450 L) at only two counts greater supersonic drag. This provided a significant increase of about 11 percent in flight mission time. This tank can also be seen at Aero India 2019.

JayS · Post by **JayS** » 28 Sep 2019 11:38

Dileep wrote:Heat removal is the number one problem in AESA. It was some jubilation when Uttam could finally fit everything into the Tejas budget.

LRDE is preparing to make LSP builds now, as per chaiwale.

ADA has special conference on Heat exchangers.

Good news on LSP. I saw there was an EOI out for ToT for production of Uttam. Most likely candidate is BEL with components from companies like Astra.

nam · Post by **nam** » 28 Sep 2019 12:13

It would be interesting to find about what IAF expects from a AESA FCR radar. The only AESA FCR we have our hands on is 2052. RBE2 is yet to come.

So it must be atleast come to 2052 in function.

LRDE must have used it's experience with MMR and it's AESA ground radar to get the confidence.

I can imagine Rafale pilots "Mere pass AESA hai", LCA pilots "mere pass bhi AESA hai...desi", with Su30 pilots "mere pass only PESA"

Aditya_V · Post by **Aditya_V** » 28 Sep 2019 12:27

We have IAF personal now in France who have had the RBE 2 in their Hands, as it have been explained no point Transporting Rafales in 1's per month which the French are able to deliver to us, the IAF is waiting to have at least 6 of them before flying them to India.

srai · Post by **srai** » 28 Sep 2019 13:46

That 450L was mentioned in that research paper on 710-ltr supersonic tank. But till now, I have not seen one photo of the “current” 450-ltr supersonic tank.

JayS wrote:
srai wrote:^^^
Is this 450L tank new addition?

Then there is a 710L supersonic tanks as well.
450L supersonic tank is been there for a while now. 710L is optimised version. From the DDR Article on LCA,

Similarly, computation fluid dynamics (CFD) studies on a variety of drop tanks have yielded fuel tank geometries which could carry more fuel at marginal to no extra cost in drag. For example, Figure 5 shows the modified supersonic drop tank arrived by choosing optimal lengths for the conical nose and tail sections. The final shape allowed the carriage of 58 percent more fuel (710 L against the current 450 L) at only two counts greater supersonic drag. This provided a significant increase of about 11 percent in flight mission time. This tank can also be seen at Aero India 2019.

JayS · Post by **JayS** » 28 Sep 2019 14:46

There were miniature models of four tanks in AI2019, including 450L SS tank. Some pics here and there, brochure and all. But, yes, I also don't remember any picture with them on LCA flying.

vishvak · Post by **vishvak** » 28 Sep 2019 16:45

I can imagine Rafale pilots "Mere pass AESA hai", LCA pilots "mere pass bhi AESA hai...desi", with Su30 pilots "mere pass only PESA"

Not to go too much OT but Without paki AWACS Su-30 with PESA would be deadly at least on this side of border for any intruder fighter jets. Wonder why people diss Su-MKI since that would be first/primary challenge to force Su-30 to switch on any active RADARs.

fanne · Post by **fanne** » 30 Sep 2019 00:29

Evolution of LCA from Vanilla LCA to Medium Weight Fighter...

https://twitter.com/strategic_front/sta ... 7790715905 ---> Evolution of LCA Mk2 design over the years (Air force version).

Mort Walker · Post by **Mort Walker** » 30 Sep 2019 02:34

Dileep wrote:Heat removal is the number one problem in AESA. It was some jubilation when Uttam could finally fit everything into the Tejas budget.

LRDE is preparing to make LSP builds now, as per chaiwale.

GaN should not have this problem unless they operate it at saturation.

Indranil · Post by **Indranil** » 30 Sep 2019 03:20

fanne wrote:Evolution of LCA from Vanilla LCA to Medium Weight Fighter...

https://twitter.com/strategic_front/sta ... 7790715905 ---> Evolution of LCA Mk2 design over the years (Air force version).

Excellent slide to show the development. The details there are very correct. Kudos to strategic front to bring this out. The yellow dots signify the position of the plugs.

fanne · Post by **fanne** » 30 Sep 2019 03:33

Idranil, just based on few numbers (engine being same, AUW increasing by 2500kg, some 17%), shouldn't MWF be 'less'. Is that mitigated by design changes (canards? and area ruling optimization) or just by need to have a plane in that range to meet MMCRA requirement. What drove that change. MK2-PDR 2014 would have had far better TWR, wing loading etc. copared to MWF. It looks like we went the same road that F-16 A went (towards F-16 D/E).
rgds

Indranil · Post by **Indranil** » 30 Sep 2019 04:37

MWF has significant L/D improvements throughtout the envelop. Inspite of lower TWR, it will have better transonic acceleration, top speed and STR. The details were in the report that Jay and I wrote.

Obviously, at MTOW, it becomes a bomb truck, just like Gripen E And Rafale. Their TWRs are around 0.6. I don't know where this becomes useful in the Indian context. Our fighter bases are close to the borders. The enemy sits right across the border with good radar coverage. We don't have a France bombing Libya kind of scenario. Also although it may be possible to arm MWF with two Brahmos or two Scalps and two big DTs, it is highly unlikely.

Cain Marko · Post by **Cain Marko** » 30 Sep 2019 06:27

Those seem like some very extensive changes. Airframe is totally different - 300mm wider, 1 meter longer at least, newer engines/intake designs. This has very little in common with the current Tejas. I wonder what the empty weight will be. This is a M2k or Gripen-E for sure. Lets hope they can keep it below 8 tons.

I hope the timelines don't stretch...

Haridas · Post by **Haridas** » 30 Sep 2019 12:13

Cain Marko wrote:Those seem like some very extensive changes. Airframe is totally different - 300mm wider, 1 meter longer at least, newer engines/intake designs. This has very little in common with the current Tejas. I wonder what the empty weight will be. This is a M2k or Gripen-E for sure. Lets hope they can keep it below 8 tons. ...

You mean from fabrication perspective ?
From aerodynamic viewpoint it's expansion around the mk1 baseline that has been well charecterized, hence canards or length or 1 ft wider fuselage are delta exploration that needs validation. From control law perspective imho it's much safer, as the canard configuration can be forced to fall back to pure double delta cranked wing

Aditya_V · Post by **Aditya_V** » 30 Sep 2019 13:51

If that table is correct and AUW means MTOW then empty weight of MWF should ~ 7700KG

sankum · Post by **sankum** » 30 Sep 2019 15:16

In tejas mk1 800 kg Misc. +2500kg internal fuel+ 6500kg empty weight + 3700 kg payload.=13500kg.
The 800 kg Misc includes 300kg 2CCM with launchers + 100kg pilot weight+ 100kg canon ammo chaff flare+ 300kg pylon weight.
If same is applied to Tejas mk2 the empty weight comes to 6900kg.

chola · Post by **chola** » 30 Sep 2019 15:34

fanne wrote:Idranil, just based on few numbers (engine being same, AUW increasing by 2500kg, some 17%), shouldn't MWF be 'less'. Is that mitigated by design changes (canards? and area ruling optimization) or just by need to have a plane in that range to meet MMCRA requirement. What drove that change. MK2-PDR 2014 would have had far better TWR, wing loading etc. copared to MWF. It looks like we went the same road that F-16 A went (towards F-16 D/E).
rgds

I think the F-16 analogy is a fair assessment. The Falcon traded thrust-weight ratio for more capability with each variant. It was the same for the F-15 and F-18 too. By the time you got to the E variants the weight had increased along with capability (BVR and A2G for example) while leaving some performance behind. The F-16N for US aggressor squads was F-16C (newer engine than A) but with a F-16A's radar set (lightest kit) which made it the greatest gunfighter in US inventory. But it was used to train US pilots with frontline systems to find and lock onto an adversary before it could come into WVR at which point it become a desperate struggle with a more maneuverable plane with incredible power to accelerate in all axis.

The MWF is larger and heavier and more capable than the MK2 2014 and so better for the frontline of a modern aur force. Better TWR for the PDR 2014 might it useful in some roles like the F-16N.

ArjunPandit · Post by **ArjunPandit** » 30 Sep 2019 16:11

Aditya_V wrote:If that table is correct and AUW means MTOW then empty weight of MWF should ~ 7700KG

does AUW stand for all-up weight?

Patni · Post by **Patni** » 30 Sep 2019 16:56

ArjunPandit wrote:
Aditya_V wrote:If that table is correct and AUW means MTOW then empty weight of MWF should ~ 7700KG
does AUW stand for all-up weight?

Yes. Its Aircraft gross weight at any given point in flight. Its maximum at lift off and decreases as fuel is used up and stores are dropped.

Dileep · Post by **Dileep** » 30 Sep 2019 19:19

Mort Walker wrote:
Dileep wrote:Heat removal is the number one problem in AESA. It was some jubilation when Uttam could finally fit everything into the Tejas budget.

LRDE is preparing to make LSP builds now, as per chaiwale.
GaN should not have this problem unless they operate it at saturation.

Actually, the Power Added Efficiency of GaN is not really better than that of GaAs. The benefit of GaN is in higher power density. You still waste power as heat, and you still need to remove it.

Kartik · Post by **Kartik** » 02 Oct 2019 07:13

This report claims that Astra BVRAAM integration with the Tejas Mk1 will begin now. Don't know how accurate it is, although it is logical, given that the Astra has completed all user trials now.

link

India's indigenous multirole light combat aircraft (LCA) Tejas will soon get more teeth with the integration of advanced air-to-air missile Astra, which may encourage the Indian Air Force (IAF) to increase its squadron strength.

The Defence Research and Development Organization (DRDO), which successfully integrated Astra on IAF's frontline air-superiority fighter Sukhoi-30MKI (Su-30MKI) will soon begin testing Astra on Tejas, reports say.

..

Cybaru · Post by **Cybaru** » 02 Oct 2019 07:55

Dileep wrote:
Mort Walker wrote:
GaN should not have this problem unless they operate it at saturation.
Actually, the Power Added Efficiency of GaN is not really better than that of GaAs. The benefit of GaN is in higher power density. You still waste power as heat, and you still need to remove it.

Can you explain that a bit better? I don't understand it.

JayS · Post by **JayS** » 02 Oct 2019 15:55

Kartik wrote:This report claims that Astra BVRAAM integration with the Tejas Mk1 will begin now. Don't know how accurate it is, although it is logical, given that the Astra has completed all user trials now.

link

India's indigenous multirole light combat aircraft (LCA) Tejas will soon get more teeth with the integration of advanced air-to-air missile Astra, which may encourage the Indian Air Force (IAF) to increase its squadron strength.

The Defence Research and Development Organization (DRDO), which successfully integrated Astra on IAF's frontline air-superiority fighter Sukhoi-30MKI (Su-30MKI) will soon begin testing Astra on Tejas, reports say.

..

In some sense, it has begun already. Simulations with missile undercarriage done, at least some of them, I was told in AI-2019. It won't take much time for integration with LCA. Because LCA has always been on their mind while making Astra. They would have considered it during design itself, sp there should be no major surprize.

JayS · Post by **JayS** » 02 Oct 2019 17:07

I dont know if this was posted here - Tweet by GP HVT, HAL's TP

https://twitter.com/hvtiaf/status/1176062910537187329

As it's already a widely acknowledged fact, Jag has a significant RoA. It's noteworthy that LCA is even better.

fanne · Post by **fanne** » 02 Oct 2019 17:30

That should put to rest range of lca. It can take care of all tactical targets in west or north

srin · Post by **srin** » 02 Oct 2019 19:32

Does RoA stand for "radius of action" ? or something else ?

Rakesh · Post by **Rakesh** » 02 Oct 2019 20:18

srin wrote:Does RoA stand for "radius of action" ? or something else ?

yes

fanne wrote:That should put to rest range of lca. It can take care of all tactical targets in west or north

And that is why the IAF must order more Mk1A squadrons. 83 is too little an order. They can solve squadron shortage problem with a stroke of a pen! Sorry if anyone finds that as hubris, but it is frustrating to see the measly 83 order. Additional Mk1As can replace a good number of the older Jaguar squadrons. If the RoA is better than the Jaguar, then why not?

One additional MiG-29UPG squadron, 18 more Su-30MKIs and 2 - 3 more Rafale squadrons. MMRCA is also done.

naird · Post by **naird** » 02 Oct 2019 20:43

Rakesh wrote: Additional Mk1As can replace a good number of the older Jaguar squadrons. If the RoA is better than the Jaguar, then why not?

Arent Jags known for extremely low level flying ! Not sure what it means to design such a/c and if LCA or any other a/c in IAF inventory is capable of that. However with updated technology and stand off PGM's - we may not even need that !

Prem Kumar · Post by **Prem Kumar** » 02 Oct 2019 21:04

Rakesh wrote: And that is why the IAF must order more Mk1A squadrons. 83 is too little an order. They can solve squadron shortage problem with a stroke of a pen! ......
MMRCA is also done.

Why MK1A sir? Even MK1 is better than Jags & Bisons. Order 4 more squadrons of MK1s & upgrade them all to MK1A standard after 4-5 years. Its frustrating to see us castrating ourselves. Someone with vision & ruthlessness must crack the whip and make this happen

ArjunPandit · Post by **ArjunPandit** » 02 Oct 2019 21:41

naird wrote:
Rakesh wrote: Additional Mk1As can replace a good number of the older Jaguar squadrons. If the RoA is better than the Jaguar, then why not?
Arent Jags known for extremely low level flying ! Not sure what it means to design such a/c and if LCA or any other a/c in IAF inventory is capable of that. However with updated technology and stand off PGM's - we may not even need that !

there have been lot of discussion here too....like the effectiveness in the presence of MANPADS..availability of MANPADS with enemy..everyone has a viewpoint...i am for max frames in air...

Indranil · Post by **Indranil** » 02 Oct 2019 22:23

JayS wrote:I dont know if this was posted here - Tweet by GP HVT, HAL's TP

https://twitter.com/hvtiaf/status/1176062910537187329

As it's already a widely acknowledged fact, Jag has a significant RoA. It's noteworthy that LCA is even better.

I know LCA's RoA. I do not know the Jag's RoA. But I expected it to be better with so much internal fuel. I guess I fell for brochure numbers here. Much to learn.

nachiket · Post by **nachiket** » 02 Oct 2019 22:57

Indranil wrote:
JayS wrote:I dont know if this was posted here - Tweet by GP HVT, HAL's TP

https://twitter.com/hvtiaf/status/1176062910537187329

As it's already a widely acknowledged fact, Jag has a significant RoA. It's noteworthy that LCA is even better.
I know LCA's RoA. I do not know the Jag's RoA. But I expected it to be better with so much internal fuel. I guess I fell for brochure numbers here. Much to learn.

The question is why weren't the brochure numbers better? When LCA was being derided with ridiculous accusations of having 300km range ADA made no effort to counter the misinformation nor to correct the information on their website, graphics at AI etc. They did all the hard work of designing an aircraft with a decent range but then failed to publicize the correct figures.

I believe the same might be true of the max payload as well. I remember when we saw the pics of the high altitude trials a few people here made back of the envelope calculations to determine that if the aircraft could take off with the visible load in hot and high conditions, its capacity at sea level would be more than what is stated.

Vivek K · Post by **Vivek K** » 02 Oct 2019 23:08

Rakesh wrote:
srin wrote:Does RoA stand for "radius of action" ? or something else ?
yes

fanne wrote:That should put to rest range of lca. It can take care of all tactical targets in west or north
And that is why the IAF must order more Mk1A squadrons. 83 is too little an order. They can solve squadron shortage problem with a stroke of a pen! Sorry if anyone finds that as hubris, but it is frustrating to see the measly 83 order. Additional Mk1As can replace a good number of the older Jaguar squadrons. If the RoA is better than the Jaguar, then why not?

One additional MiG-29UPG squadron, 18 more Su-30MKIs and 2 - 3 more Rafale squadrons. MMRCA is also done.

Admiral sahab - Ghar ki murgi daal barabar! After ordering 72 Rafales @ $215 million a pop, 18 more MKI and One new Mig-29 UPG squadron where will the money for additional LCAs beyond the 40 FOC come from? They haven't even ordered the 83 yet. So effectively swap Rafales and their "tremendous capability" for more LCAs.

fanne · Post by **fanne** » 02 Oct 2019 23:11

Btw the nap of the earth flying for a longer range bomber (like Jags, that it can fly low and a circuitous route to target) is still a very valid scenario to beat enemy defense. Pop out few miles ahead of target from an unsuspecting direction, use smart munition and disappear back in the clutter.
Jags with high wing loading can do it (LCA cannot, very low wing loading, it will crash if flies near the ground with so much turbulence, or the pilot would have separate barf bag attached to his suite).
We do read report that awacs can pick aircraft that are rolling off the airport, if it is true, then low flying has lesser usefulness. You can still fly behind a mountain, hill etc and surprise the enemy.

Vivek K · Post by **Vivek K** » 02 Oct 2019 23:32

Are you sure - LCA with its FBW cannot fly low?

Cybaru · Post by **Cybaru** » 03 Oct 2019 00:07

fanne wrote:Btw the nap of the earth flying for a longer range bomber (like Jags, that it can fly low and a circuitous route to target) is still a very valid scenario to beat enemy defense. Pop out few miles ahead of target from an unsuspecting direction, use smart munition and disappear back in the clutter

The hard deck for bombing runs has gone way higher! Threat matrix is too dense for low level stuff.

Karan M · Post by **Karan M** » 03 Oct 2019 00:08

fanne wrote:Jags with high wing loading can do it (LCA cannot, very low wing loading, it will crash if flies near the ground with so much turbulence, or the pilot would have separate barf bag attached to his suite).

Wrong!! The Mirage 2000s routinely fly low and even bounce the Jaguars. The FBW exists for a reason.