LCA Tejas Mk1 & Mk1A - News and discussions

[LX1111]

Please do not make idiotic arguments. It's common sense.

View attachment 32826

HAL HF-24 Marut - Wikipedia

en.m.wikipedia.org

The HF 24 has a German design and performs more ground attack missions on the battlefield due to its weak engines. Basically no supersonic flight,
China also has a more mature Q 5

强5 - Google Search

 

[Ashwin]

A B- 787 certainly has a larger RCS than a small Cessna, But that doesn't apply to all scenarios. The B 2 is larger than most fighters, But its RCS is smaller than all of today's fighters
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The picture itself shows how the RCS goes down with size.

When talking about non stealth fighter there is place for B2.

 

[LX1111]

Overall size is a factor.

Besides that, LCA has a Y-duct inlet layout that totally shields the fan blades.

And, it has an extremely high degree of composite usage in airframe which also reduces radar reflectivity.

View attachment 32828

Its not an LO fighter, but compared to something like an MKI, it's going to have a far smaller RCS.

The Tejas certainly have a smaller RCS than the su 30 series, but it is doubtful whether they have reached the 0.5 he claims
But does India really believe that its composites are Far more than the F 35？ at 45%, Even so, the Tejas are nearly a ton heavier than expected

 

[LX1111]

The picture itself shows how the RCS goes down with size.

When talking about non stealth fighter there is place for B2.

So, for the Tejas, which basically doesn't have any stealth design,because is it too small can reach the claimed 0.5?

 

[Parthu]

The Tejas certainly have a smaller RCS than the su 30 series, but it is doubtful whether they have reached the 0.5 he claims
But does India really believe that its composites are Far more than the F 35？ at 45%, Even so, the Tejas are nearly a ton heavier than expected

I cannot attest to the exact figure but a sub-1m2 RCS isn't hard to achieve for a 4th gen plane with that amount of composite content - as long as it's operating with a clean load.

But in a combat situation that's irrelevant because any external missiles or tanks will increase it to several square meters by themselves.

 

[Ashwin]

The HF 24 has a German design and performs more ground attack missions on the battlefield due to its weak engines. Basically no supersonic flight,
China also has a more mature Q 5

强5 - Google Search

Oh, do you really want to go in that direction? Are we so naive to believe that the Chinese developed a fighter in the 1970s without any help?

J-8 was designed with the assistance of Soviet then later J-8B with Americans.

Remembering The Time Grumman Helped Craft A Modern Fighter For China

The brief thaw in America’s relations with China in the 1980s yielded this surprising hybrid fighter program led by Grumman.

www.twz.com

So, for the Tejas, which basically doesn't have any stealth design,because is it too small can reach the claimed 0.5?

I did not make that claim. However, having a smaller size than any operating multi-role 4th generation fighter does help in terms of RCS.

 

[Rajput Lion]

@LX1111, ~0.5m2 is the often quoted number for Tejas' RCS. Actual clean frontal RCS of the upcoming MK1A variant might be even better(read lower) because of use of better RAM paint/coat. According to the French, Mirage-2000's clean frontal RCS is 0.8m2-1m2. Rafale's clean frontal is 10 times lower so around 0.08m2-0.1m2. Tejas being physically smaller, using Y-shaped intakes which hide engine blades and high use of composites in the frame can easily beat M-2000's clean frontal RCS. So anything between 0.3m2-0.5m2 isn't out of realms for Tejas.

Read this analysis to increase your knowledge regarding Tejas' RCS: Analysis:- Does LCA Tejas posses stealth?

 

[Rajput Lion]

It's hilarious how Mr. Chinese is doubting Tejas's 0.5m2 clean frontal RCS figure which is completely believable while his own countrymen/media/air force pilots are claiming that J-16 has become semi-stealth because of a new RAM coat:

The new coat will provide the J-16 a level of stealth capabilities not only against the naked eye but also with electromagnetic devices, said Chinese Air Force pilot Jiang Jiaji last year on China Central Television.

Source: Chinese military aircraft to receive new stealth coatings - People's Daily Online

 

[Ashwin]

 

[LX1111]

It's hilarious how Mr. Chinese is doubting Tejas's 0.5m2 clean frontal RCS figure which is completely believable while his own countrymen/media/air force pilots are claiming that J-16 has become semi-stealth because of a new RAM coat:



Source: Chinese military aircraft to receive new stealth coatings - People's Daily Online

I don't see any reasonable Chinese claiming that the J-16 is a semi-invisible aircraft, this report is Just that it is used to absorbing paint，

 

[LX1111]

@LX1111, ~0.5m2 is the often quoted number for Tejas' RCS. Actual clean frontal RCS of the upcoming MK1A variant might be even better(read lower) because of use of better RAM paint/coat. According to the French, Mirage-2000's clean frontal RCS is 0.8m2-1m2. Rafale's clean frontal is 10 times lower so around 0.08m2-0.1m2. Tejas being physically smaller, using Y-shaped intakes which hide engine blades and high use of composites in the frame can easily beat M-2000's clean frontal RCS. So anything between 0.3m2-0.5m2 isn't out of realms for Tejas.

Read this analysis to increase your knowledge regarding Tejas' RCS: Analysis:- Does LCA Tejas posses stealth?

I cannot attest to the exact figure but a sub-1m2 RCS isn't hard to achieve for a 4th gen plane with that amount of composite content - as long as it's operating with a clean load.

But in a combat situation that's irrelevant because any external missiles or tanks will increase it to several square meters by themselves.

I summed up the Indian view that the tejasuses a so-called Y-shaped inlet that blocks the radar blades, The Tejas uses composite materials, the Tejas uses a wing-bodY fusion design, and the Tejas are small enough

 

[LX1111]

I summed up the Indian view that the tejasuses a so-called Y-shaped inlet that blocks the radar blades, The Tejas uses composite materials, the Tejas uses a wing-bodY fusion design, and the Tejas are small enough

I think we can compare it with the JAS 39, whose RCS is 1.5 ~ 2 ㎡ in X band
He also used what the Indians call a Y-shaped inlet
And its surface doesn't have as many bulges and cooling air intakes as the Tejas
In my image, the red arrow refers to the boundary layer barrier of the tejas inlet
This is a natural giant corner reflector
The blue arrow refers to the large number of cooling ports on the surface of the Tejas, and the effect on the RCS is large

 

[LX1111]

I thought the Indians didn't know about the Tejas inlet，It is strange that a fighter with an obvious emphasis on supersonic performance should use the fixed baffle inlet commonly used in subsonic fighters.
With this inlet at Mach 1.6, the total pressure recovery coefficient is only 0.78. No wonder the Tejas can only fly Mach 1.6.
For Comparison, the DSI inlet on J 10C has a total pressure reCovery CoeffiCient of 0.91 at MaCh 1.8 ,though MaCh 2.0 is 0.87.

The total pressure recovery coefficient is a measure of the degree of flow loss in the inlet. Total pressure recovery coefficient decreased by 1% , thrust decreased by 1.5% -2% , fuel consumption increased by 0.3% -0.5%
That is, at MaCh 1.6, assuming the same engine, the TeJas would have 20 %-25% less thrust than the J 10C

 

[Saaho]

I think we can compare it with the JAS 39, whose RCS is 1.5 ~ 2 ㎡ in X band

it is comparable to Grippen E/F having a RCS of 0.5 or so. Tejas uses a lot of composites. One of the highest composite based airframe around there.

 

[LX1111]

it is comparable to Grippen E/F having a RCS of 0.5 or so. Tejas uses a lot of composites. One of the highest composite based airframe around there.

In the early days, the Tejas did have a 45% design goal of using composite materials, but whether this goal was achieved, given the fact that Tejas is now substantially overweight, I doubt it,
, the reflection of electromagnetic waves on non-metallic surfaces is weaker than that on metallic surfaces, but this does not mean that it does not reflect electromagnetic waves. JAS39E/F has covered the scattering source on the surface during design, which reduces its RCS. As for the 0.5 you mentioned, it may occasionally be achieved at a certain angle, but the actual situation will never be so ideal

 

[randomradio]

The magic word is "supposed". As for now nothing near a serial production.

RBE2 AESA has now more than 12 years (first delivery in 2012). I don't know if some hardware changes have been made on it since. If not it's not unatural that some more recent are more potent. I hope there was improvements on memory size, CPU,... but I really don't know.

But if Hardware is one thing, software is another. The soft of a radar is not so easy to developp and fine tune. It takes years.
On this field something intersting about RBE2 AESA is that it was studied so as to use all the soft developp for PESA one (ie 15 years of refinement). When the other AESA come with nearly no soft except basic air to air modes, the french one came immediatly with F3 standard, so with air to air, air to ground, air to sea modes. And since every 2 year there are new releases.

It's a problem if the Rafale's only advantages become hardware and software maturity while leaving next gen to the Indian industry.

 

[screambowl]

The Tejas certainly have a smaller RCS than the su 30 series,

What is the RCS of Mig21 and M2K compared to Mk1 LCA? They all should be in a similar size and spectrum.

 

[randomradio]

I don't see any reason why a Tejas has such a small RCS, or you just think it's small enough that its RCS can be very low

We do not have actual figures, but as per ADA, the RCS is three times smaller than the Mirage 2000.

 

[LX1111]

What is the RCS of Mig21 and M2K compared to Mk1 LCA? They all should be in a similar size and spectrum.

They're not the same size. The MIG 21 is a light fighter, and its RCS is around 3㎡, This is also the target used by Soviet radar to describe its range. Mirage 2000 is a medium-sized fighter. His RCS is generally thought to be around 4-5㎡

 

[screambowl]

So, for the Tejas, which basically doesn't have any stealth design,because is it too small can reach the claimed 0.5?

Then what is the expected range it could achieve, if not 0.5m²?
Even the Chinese have done well in material technology and building composites but I think no Chinese light weight or medium weight fighter like J17 or j10c can achieve 0.5 m² so far from their designs from every angle.