LCA TEJAS MK1 & MK1A: News and Discussion

Emperor Kalki

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The be most vital advantage of supercruise is that the troops on the ground will not hear your jet until you have crossed way past them & reaching target in matter of minutes... Thus less time to react (Ofcourse for it to be truely effective the jets needs to be stealthy).
View attachment 56321
What did you mean?
 

Bleh

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...and again for this to work, the aircraft must be a true stealth aircraft
Yes, or else the radars will have detected it already. So inputs from ground troops won't matter.
This is why in 4th gen jets supercruise is unimportant unless it is designed as a EW prodigy like Gripen-NG.
 

WolfPack86

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Deal To Buy 83 LCA Tejas Mark 1A Jets And Indigenous Attack Helicopters For IAF Close To Fruition
Prime Minister Narendra Modi while addressing the nation from the Red Fort on the occasion of India’s 73rd Independence Day said that the deals to buy LCA Tejas aircraft and indigenous attack helicopters for the Indian Air Force (IAF) are close to fruition. As per defence news website Livefist, this is the first time that either the LCA Tejas aircraft or the light combat helicopter have been mentioned in an Independence Day speech. Under the indigenous defence deals, the government is expected to procure 83 indigenous Light Combat Aircraft (LCA) Tejas Mk.1A jets from HAL in a deal worth $5.2 Billion. The final paperwork for the deal is reportedly complete and awaiting clearance from the Ministry of Finance. LCA Mark 1A will be a more capable fighter than the original Mark 1 variant. Mark 1A variant of the LCA will come with around 40 major and minor improvements over Mark 1. These improvements include the introduction of an active electronically scanned array radar for detection of enemy aircraft at greater ranges and resistance to jamming, and a faster turnaround of each aircraft after each sortie. It was earlier reported that the HAL had ramped up production for the Light Combat Helicopter (LCH) in Bengaluru after getting a signal that a contract for the same is near.
 

Emperor Kalki

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He meant,
Since the aircraft is travelling faster than sound, by the time the ground troops hear the sound of the aircraft, it will be gone since it is travelling faster than sound itself, and again for this to work, the aircraft must be a true stealth aircraft
That's not the advantage of suprecruise per se. But rather an advantage of supersonic flight itself.
What supercruise brings to the table is primarily lower fuel usage for lower supersonic speeds and then all the other stuff.
And trust me, the jets won't be "cruising" in such a situation as you said.....
 

WolfPack86

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LRDE Pushing for Uttam AESA for Last Batch of Tejas Mk-1A

The home-grown Uttam Active Electronically Scanned Array (AESA) radar developed by Electronics & Radar Development Establishment (LRDE) seems to be making the right moves to get the attention of the Indian Air Force (IAF). With the addition of AESA radar being one of the key features of Tejas MK1A, LRDE hopes that Uttam can even meet the schedules of the upgraded programme. It has already completed more than 100 hours of flying on a hired aircraft and nearly 25 hours on Tejas test platforms. It is now confirmed that Uttam’s air-to-air mode and its sub-mode functionalities have been already tested. Uttam is in competition with the Israeli Elta radar and the official word is not yet out on the question of how many Tejas MK1As (total 83) will be fitted with the desi technology. LRDE scientists are pinning their hopes on the Aatmanirbhar Bharat mandate.
 

Bleh

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I was not asking about not using afterburner advantages.

To be more clear, what is the big advantage for Tejas going at 1100kmph @ 30k ft over 900kmph @30k ft ?
Both cases do not engage afterburner. Mach 1 vs less than mach 1.
He meant,
Since the aircraft is travelling faster than sound, by the time the ground troops hear the sound of the aircraft, it will be gone since it is travelling faster than sound itself, and again for this to work, the aircraft must be a true stealth aircraft
That's not the advantage of suprecruise per se. But rather an advantage of supersonic flight itself.
What supercruise brings to the table is primarily lower fuel usage for lower supersonic speeds and then all the other stuff.
And trust me, the jets won't be "cruising" in such a situation as you said.....
Here's what I meant... The time lapse will be much higher for a jet supercruising at 30kft altitude.

IMG_20200816_204042.png

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And no there's no drag advantage until you are at Mach 5, which is why all the fuss about hypersonic flight.
qXnqu.gif
 
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piKacHHu

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Here's what I meant... The time lapse will be much higher for a jet supercruising at 30kft altitude.

View attachment 56394
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And no there's no drag advantage until you are at Mach 5, which is why all the fuss about hypersonic flight.
qXnqu.gif
IMO, this is not deemed as advantage of Supercruise w.r.t response at ground level.;

1. Considering ground troops equipped with MANPADs, aircraft cruising at 30K is out of range for any contemporary MANPADs (For e.g. Stinger up to 20k feet).

2. Considering sunny & clear sky, as the height increases so is the arc of travel for given FOV angle. (theta = arc/radius); so even if the aircraft is super cruising accompanied by shock wave, it's still remain visible for quite a longer time. Unlike, the low level supersonic dash being made by fighters to evade missiles or radar, the aircraft disappears in seconds (again due to lower radius, arc for the given FOV will be smaller)

As per my understanding, Supercruise essentially gives you a better range for BVR combat . You can steadily reach the engagement zone at 30k-40k feet without using afterburner ; Do the FOX 3 and turn cold with ample fuel left for any defensive maneuver. (Pitfall is that you may be detected earlier at 30k height with the help of AWACS.)

Hypersonic regime is another ball game; even though the drag goes down, the heating due to adiabatic compression makes conventional aerofoil design untenable. So a mix of design is chosen that can optimize both supersonic-hypersonic transition and the heat generation over its surface.
 

Bleh

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As per my understanding, Supercruise essentially gives you a better range for BVR combat . You can steadily reach the engagement zone at 30k-40k feet without using afterburner ; Do the FOX 3 and turn cold with ample fuel left for any defensive maneuver. (Pitfall is that you may be detected earlier at 30k height with the help of AWACS.)
Only this quoted part is correct.

Manpads aren't an issue. Detection & relay of the info is.

It's damningly difficult to notice a tiny jet 10km above if you can't hear it. It is visible, but by the time you hear it at a forward post it is already 100km inside your territory & will teach target by the time you relay the info & the enemy reacts... Again only works for stealthy airframes.
 

piKacHHu

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Only this quoted part is correct.

Manpads aren't an issue. Detection & relay of the info is.

It's damningly difficult to notice a tiny jet 10km above if you can't hear it. It is visible, but by the time you hear it at a forward post it is already 100km inside your territory & will teach target by the time you relay the info & the enemy reacts... Again only works for stealthy airframes.
Have you done the math for quoting"100 kms" figure?

Assuming the plane got supersonic just vertical over the goatfcker...

Speed of sound (in air at standard conditions): 1235 km/hr
Observer distance: 10 kms (>30000 ft)
Time taken by sonic boom to reach the ground observer: 0.5 minutes (30 seconds)

Distance traveled by the aircraft after sonic boom reached the goatfcker (lets say travelling at Mach 1.5 which is approx. 1852 km/hr): 16 kms ONLY

So, you are off by more than 5 times at your claimed figure of 100 kms. Now, calculate the FOV angle, you will find that its still within the human limitation.

For aircraft nearing MACH 1 or above; Con-Trail gives better visual ID than the aircraft itself. My point is that super-cruise doesn't give you advantage like the way you are presenting it particularly in the modern era dominated by EW Radars and surveillance.
 

johnq

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Are there any plans for the centerline hardpoint to be used for a towed ECM decoy?
 

Bleh

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Time taken by sonic boom to reach the ground observer: 0.5 minutes (30 seconds)

Distance traveled by the aircraft after sonic boom reached the goatfcker (lets say travelling at Mach 1.5 which is approx. 1852 km/hr): 16 kms ONLY
No no sorry, I meant by the time gap for response.
Subsonic jet will be heard before it reaches & he'll easily make visual contact then... But a sudden sonicboom echoing all over the place is more jarring as well as don't give away a direction.

So the time difference in which he can relay the info, say 2-3 minutes.
Even if the enemy responds within another 5 minutes (near impossible), you have released your ordnamce & turn to return home.

Most fighter jets don't leave trail in dry thrust.... Again, stealth & supercruise must go together.

Are there any plans for the centerline hardpoint to be used for a towed ECM decoy?
Unknown. Also towed-decoy is messy. Not everyone wants them.

To spoof the enemy by feeding wrong positioning data can be done without it.
 
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Lancer

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Big. For the first time, India's Tejas & Light Combat Helicopter mentioned in an #IndependenceDay speech. PM
@NarendraModi
invokes both. Confirms that both deals are near:
I know we've all said it before, but I really hope they either increase the order sizes (for both) at the same PPU, or at least quickly place follow-on orders later on.

Waiting this long, with such a gaping void of fighters/attack helos - only to end up with such small numbers seems self-defeating.
 

Chinmoy

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With new engines and refinements they can make it to supercruise as MK1 is already at 74% speed of mach 1, though increased payload will also be there to limit its speed.
In simple layman term, the change in engine alone is not going to help Tejas in supercruise. The thrust available would be same.

But yes, if we change it from a single to twin engine, the numbers could add up.
 

A chauhan

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In simple layman term, the change in engine alone is not going to help Tejas in supercruise. The thrust available would be same.

But yes, if we change it from a single to twin engine, the numbers could add up.
Actually Gripen can supercruise @1.1 Mach with the same engine as in MWF with some aerodynamic refinements. It is said about Tejas that some refinements can be done to reduce drag, and if it is true then there is a possibility to get it supercruise capability.
 

Steven Rogers

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Actually Gripen can supercruise @1.1 Mach with the same engine as in MWF with some aerodynamic refinements. It is said about Tejas that some refinements can be done to reduce drag, and if it is true then there is a possibility to get it supercruise capability.
Gripen supercruise due to its design and area ruling,Tejas isn't designed with the area ruling in mind so the transonic and supersonic drag in LCA is higher than Gripen.Engine change will not help much....
 

piKacHHu

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Most fighter jets don't leave trail in dry thrust.... Again, stealth & supercruise must go together.
I don't know who is feeding you wrong information about con-trail !!

Contrail is not associated with supersonic flight alone & the use of after burner in particular. You may see it even for M==0.85-0.9 at cruising altitude for civilian aircraft; Check this picture; Airbus 340 at cruising altitude(30-35k feet); I hope civilian turbofans engines doesn't use wet thrust !!

1280px-Vapour_trails.jpg


F-16 with contrails
6274804510_ee55c4ca21_b.jpg


For BVR engagement at cruising altitudes (for which most of the fighter jet have claimed supercruise capabilities), the visual confirmation via contrails plays an important part in highly cluttered environment. That's what the "FSO" of Rafale is supposed to do that; to visual ID the bogey at longer distance. Check out the extent of contrail left behind by fighter jets doing combat maneuvering (F15s intercepting a pair of Migs).

271px-Mig-29s_intercepeted_by_F-15s_-_DF-ST-90-05759.jpg


Picture courtesy : Wikipedia/Google
Subsonic jet will be heard before it reaches & he'll easily make visual contact then... But a sudden sonicboom echoing all over the place is more jarring as well as don't give away a direction.

So the time difference in which he can relay the info, say 2-3 minutes.
Even if the enemy responds within another 5 minutes (near impossible), you have released your ordnamce & turn to return home.
True; but then this scenario comes only when you are fighting war with sub-saharan countries with technologies dating back to WWI.
So far, the only aircraft with internal weapon bay that can supercruise and drop the ordinances is F-22 (in active service; not sure about J-20); even for that I would say going sonic over enemy territory is counter productive for strike missions unless you are just trying to intimidate them. Sonic boom can affect larger area around its passage rather than the sub-sonic flight meaning you are alerting larger number of people about its presence. From my perspective, significant utility of going sonic is in high speed interdiction; BVR combats, and defensive maneuvering.

There is a reason to the decline of usage of high altitude & high speed Mig 25 due to arrival of advanced EW radars and longer range SAMs.
 

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