LCA TEJAS MK1 & MK1A: News and Discussion

SUPERPOWER

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I repeat again, why the eff did they not integrate astra from day one and get on with it ? Now changing from python to derby to asraam...typical IAF
Our forces love testing that too they love to test it for years and years and when Pakistan and China attacks they will go for weapon buying spree that too at double cost ...sab chalta tha, hai aur rahega who cares..
 

omaebakabaka

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I repeat again, why the eff did they not integrate astra from day one and get on with it ? Now changing from python to derby to asraam...typical IAF
I would not pay attention to these secondary efforts, if production slows down or deployments do not happen with signed orders, that mean bidet admin caused road blocks in the imports either with their own IP or forced Israel to cool down....what do you guys think? Even basic project manager and idiotic customer does not behave this way in executing a project
 

cannonfodder

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Was browsing BR and looked at some posts on OBOGS. Any news which version will have it?
MK1, MK1A or MK2.
 

Bleh

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2:19 Tejas cockpit right????????
Why will it be Tejas cockpit in a Su-35 video?.. Those cockpit-cams all look similar.

Edit: Ok, they may have used Tejas' footage at that moment.

Was browsing BR and looked at some posts on OBOGS. Any news which version will have it?
MK1, MK1A or MK2.
Is being tested on LSP Tejas.. Only 15kg in weight. If cleared it can be mounted on LCA by replacing the cylinder. Nothing too complicated.
 
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MonaLazy

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As confirmed by HVT, it's for the Tejas Mk1A.
MWF over Mk1A
For the record..


Mk1A


It will probably have the L-band CIT-dipoles, embedded.


Upgraded AAAU with 912-1000 TRMs.

Also recall Dr Madhusudhana Rao's DDR interview in which he said Mk2 will have smaller radome (consequently smaller AESAR) than Mk1/1A to accommodate IRST and other new sensors 270mm of the radome has been cut. However, Antennae Aperture Unit of Uttam has been redesigned for Mk2 and we are accommodating more elements than Mk1A- 780 elements in Mk1A, 992 for Mk2 which gives enhanced performance than Mk1 + other improvements in AAAU. @sriramthg sums it up as "A smaller nose cone (in Mk2 vs Mk1/1A) has a redesigned radar with higher TRMs giving higher performance"


Based on this info couple of questions/observations:

1. Any benefits of embedded dipoles in the upgraded radar other than compactness & perhaps lower power requirement? (anything embedded inherently saves space & power)

2. From 780 TRMs in Mk1A we have gone up to 912-1000 TRMs in upgraded Uttam- which is about the same or marginally lesser than in Tejas Mk2 at 992 despite Mk1A having a larger radome than Mk2. Both Dr Rao and Indranil Ray confirm this is because of power/cooling requirements placed on the power plant.


Available engine power limits the number of TRMs. LCA's nose is oversized for a light aircraft.

If we had a more powerful engine in the same factor we could make full use of the Tejas Mk1A's nose by jam packing it with TRMs of AESAR. One of the smallest fighter aircraft in the world with the capability to see far, very very far. :drool:

or put in an IRST with the existing setup to make use of the vacant nose space..
https://twitter.com/Indrani1_Roy/status/1392978014804213760?s=20

But this gives another low ganging fruit. With the newer tech, can we build a smaller aperture radar for Mk1/Mk1A, and use the extra space in the nose for an IRST and/or retractable IFR.
 

MonaLazy

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270mm of the radome has been cut
Just had an itch to figure out what is the max TRMs we could possibly fit in Mk1A, based on the information we have. I did arrive at a number and this is how I went about it:

1612081622-3521.jpg


270mm cut in radome is info gleaned from the DDR video and since it makes way for IRST & other sensors the above seems to be the most logical direction of radome shrinkage when going from Mk1/A to Mk2. The arrow length above is probably what Dr Rao gave out.


Also was looking for approximate dimensions of the Mk1 radome and chanced upon this link:
LCA-Tejas-Radar-Nose-Diagram.jpg


Length of Mk1/A radome= 1972mm
Dia of fuselage interface = 883.5mm

BIG assumption- the above figure is authentic information

So for Mk2,
Length of Mk2 radome= 1972-270 mm = 1702mm
Dia of fuselage interface = ? (say x)

Solving for similar triangles assuming again that the basic geometry of the two radomes is similar, Mk2 is just a scaled down version of Mk1A
x/883.5=1702/1972
gives x=759.81mm

Now, with no power problems on Mk2 it supports 992 TRMs
So for Mk1A 992*(883.5*883.5)/(759.81*759.81)=1341.26
.. assuming circular arrangement of TRMs in AESAR (ratio of area of two circles pi*r*r is the ratio of their radius to the power of 2)

Lots of assumptions in these very back of the envelope calculations with very basic maths hopefully correctly applied. But if correct we could have done about 1300 TRMs in Tejas Mk1A AESAR. For perspective (info from Google chacha) AN/APG-81 of F-35 has 1,676 GaAs T/R modules, & AN/APG-77 radar on F-22 has a total of 1956 T/R modules (both jets have ample power onboard), and Tejas is supposed to be a 'Light" fighter. I think it punches well above its weight even in Mk1A config!
 
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Lonewolf

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Just had an itch to figure out what is the max TRMs we could possibly fit in Mk1A, based on the information we have. I did arrive at a number and this is how I went about it:

View attachment 89981

270mm cut in radome is info gleaned from the DDR video and since it makes way for IRST & other sensors the above seems to be the most logical direction of radome shrinkage when going from Mk1/A to Mk2. The arrow length above is probably what Dr Rao gave out.


Also was looking for approximate dimensions of the Mk1 radome and chanced upon this link:
View attachment 89982

Length of Mk1/A radome= 1972mm
Dia of fuselage interface = 883.5mm

BIG assumption- the above figure is authentic information

So for Mk2,
Length of Mk1/A radome= 1972-270 mm = 1702mm
Dia of fuselage interface = ? (say x)

Solving for similar triangles assuming again that the basic geometry of the two radomes is similar, Mk2 is just a scaled down version of Mk1A
x/883.5=1702/1972
gives x=759.81mm

Now, with no power problems on Mk2 it supports 992 TRMs
So for Mk1A 992*(883.5*883.5)/(759.81*759.81)=1341.26
.. assuming circular arrangement of TRMs in AESAR (ratio of area of two circles pi*r*r is the ratio of their radius to the power of 2)

Lots of assumptions in these very back of the envelope calculations with very basic maths hopefully correctly applied. But if correct we could have done about 1300 TRMs in Tejas Mk1A AESAR. For perspective (info from Google chacha) AN/APG-81 of F-35 has 1,676 GaAs T/R modules, & AN/APG-77 radar on F-22 has a total of 1956 T/R modules (both jets have ample power onboard), and Tejas is supposed to be a 'Light" fighter. I think it punches well above its weight even in Mk1A config!
Powerr ?????


Powerrrrrrrrrr ???????




.powewwwrrrrrrrr
 

MonaLazy

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Powerr ?????
..not enough. Those fanboy calculations were only to arrive at a theoretical max TRM count based on info available. Lot of simplifications in there.. like assuming circular arrangement, when the diagrams show it is square with rounded edges. But still it shows the original designers were far-sighted to give it a giant nose so it could see first, shoot first and a small size to be undetectable itself. Such clever planning, but it ran foul of onboard power.
 
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