HAL Tejas | Updates, News & Discussions-[Thread 2]

[Abingdonboy]

 

[sancho]

Why is that Mk1 is limited to 8g ??

Those are the development goals for the FOC.

 

[kurup]

Those are the development goals for the FOC.

Which means 8g has not been achieved yet .

Lets say they will achieve it for FOC .

But my question still stands , most modern fighters can reach 9g while Tejas is limited to 8g .... why ??

 

[sancho]

Which means 8g has not been achieved yet .

Lets say they will achieve it for FOC .

But my question still stands , most modern fighters can reach 9g while Tejas is limited to 8g .... why ??

Nope, the reports around IOC 2 stated 6 to 7G and 22 to 24° AoA, which they need to improve. Earlier specboards showed 9G as the limit too, so this might be one of the performance limitations of the MK1, that needs to be fixed in the MK2.

P.S. ADA specboards from Aero India 2011 and from their website:

 

[sancho]

sancho View attachment 192901

Just went through the new brochures and might get an idea about the fuel tank now, because it seems like the fuel tank is added below the telemetry equipments:

Marked:

- refuelling probe
- new fuel tank within the cockpit section
- new fuel tank in the extended airframe
- wing fuel tanks
- centerline fuel tank (most likely 725l)

And as I assumed, the idea is to add enough internal fuel, to just use a single additional centerline fuel tank, compared to 2 x wingfuel tanks on the LCA MK1 versions. That free's wingstations to carry a full set of 4 x AAMs + 2 x bombs or anti ship missiles.

 

[Bratva]

Why is that Mk1 is limited to 8g ??

To maintain the structural integrity.

 

[Sri]

Looks like both the versions LCA MK2 and NLCA MK2 are completely different A/Cs. Both have quite diff dimensions.
Official LCA Tejas Brochure 2015
Official LCA Navy Brochure 2015

Courtesy Karan BRF.

 

[kurup]

Nope, the reports around IOC 2 stated 6 to 7G and 22 to 24° AoA, which they need to improve. Earlier specboards showed 9G as the limit too, so this might be one of the performance limitations of the MK1, that needs to be fixed in the MK2.

P.S. ADA specboards from Aero India 2011 and from their website:
View attachment 193185 View attachment 193186

What will be drawback of limiting to 8g than 9g ??

To maintain the structural integrity.

So if it goes to 9g , the structure will disintegrate ??

 

[sancho]

What will be drawback of limiting to 8g than 9g ??

It will not be able to do the full range of maneuvers, since the FCS limits the pilot. It's usual to slowly expand the flight profile of new fighters and if the 8G and 26° AoA will be reached with the MK1, it's still a good achievement. The latest figures in the brochure confirm 24° achieved so far for the MK1 and 9G as the aim of MK2.

 

[sancho]

@Manticore @sancho One question.

The internal fuel of LCA Mk.1 is around 2458 kg in compare to 2230kg and 2270kg of JF-17 and Gripen C/D.

To not spoil the other thread with LCA discussions...

...offically it was given on the IOC press release with:

It's Radius of Action is upto 500 km depending upon the nature and duration of actual combat.

But as @Manticore, range specs are dependent on the conditions that they are based on. Combat range or combat radius (500Km radius = 1000Km range), what flight profile, what payloads...and without knowing them, you can't compare the figures or how reliable they are.
Drag is certainly an issue for LCA, but surely not to such a difference like the speculated figures show, otherwise the speed figures would also have a similar difference.

 

[sancho]

N-LCA NP2 & N-LCA MK2

Gripen C/D & Gripen NG:

So they redesign not only the fuselage, but also the fairings under the wings of the N-LCA MK2, which then leads to the changes of the wingspan, which is comparable to what Saab has done with the Gripen NG. The interesting part however is, that they doesn't seems to to gain wrt to centerline weaponstations, but also that the IAF MK2 doesn't seems to have the same changes of the gearbay, since it's span remains the same as of LCA MK1s.

That however hardly makes sense, when you go for such a large re-design of the fuselage, why not use it to add more weapon stations and why not give the IAF version the same gear bay with a much lightened version of the new gear. That would give you more commonality and just a single set of gears, with some modifications, rather than 2 completely different gears.

 

[sudhir007]

 

[Major Shaitan Singh]

https://twitter.com/x/status/567203589194412032

https://twitter.com/x/status/567203194237771777

In preparation for Aero India expo: Tejas TD2- techies attaching the wing

 

[sudhir007]

 

[vsdave2302]

That's why the IAF wanted "some" more thrust and initially stated the need for around 90kN, but then the navy came in with their requirements and added many things and now we have to wait for a proper MK2 prototype to see what can be achieved and what not.



The first MK2's will be based on the IAF version, but the MK2 upgrade as such, will mainly include IN's requirements. That's why the airframe needs to be lengthened to include more fuel and most likely why the fuselage will be re-designed to include enough space to include the N-LCA gears, without the hump that we can see on the NP1 and 2, so a more aerodynamic design. These modifications however might be a burden for IAF, since they increase the base weight of the fighter, which counters the higher trust to some extend again. The crucial point will be, how much more fuel can be carried internally, because that decides how many external fuel tanks needs to be carried in each mission. If it's enough to just carry 1 centerline 725l fuel tank, instead of 2 x 1200l tanks at the wings, you will reduce drag to a good extend.

The performance of the N-LCA will be even more tricky to evaluate, since from what we see now, it will be based on the twin seat version which alone adds more weight and drag by design. Add the weight of the navalisations and the higher operational limits of using it from short take off distances and possibly reduced payload can't really make it very capable.

Thanks Sancho but there is a proposal to use 108KN derivative of GE 414 on N LCA so far as I know. That should take care of additional weight etc. Moreover, N LCA performed better than expected with a almost double climb ratio. They have planned to decrease landing gear weight at par with Air force tejas. i.e. 600 KG. So all in all N Tejas MK2 with a weight of ,7.0 tons with 108 KN engine is laieky to give some handsome T/W ratio. MK2 shall have aerodynamic improvement as well. So over all we may expect a very good multirole single engine carier copetable platform.