ADA Tejas (LCA) News and Discussions

[Archer]

What when?

 

[abhi_the _gr8_maratha]

@ ersakthivel, power monger, bramastra many quality posts from you but can't like. Technical problem in forum.

 

[abhi_the _gr8_maratha]

When Germans were interested in LCA-Tejas Trainer | idrw.org
.
.
Interestingly Americans too in past
had asked Indian agencies if joint
development of a Trainer aircraft
could be carried out , idrw.org cannot
confirm if they were talking about LCA
Trainer . Report does mentions that
LCA Trainer could have been a serious
contender to American T-X program,
which sought to replace ageing T-38
Talon from USAF fleet, if such proposal
was accepted .

 

[Pandora]

Mr das replied our posts @ersakthivel

 

[abhi_the _gr8_maratha]

Mr das replied our posts @ersakthivel

can you post the link mate?

 

[brahmastra11]

Any guess ?? Who is Mr das in DFI ?

 

[SajeevJino]

Any guess ?? Who is Mr das in DFI ?

PM me Please

 

[Kunal Biswas]

The extend they have constructing their force is risking national security of this nation, A Airforces which is 98% imported has no reserve pilot strength in war time, They have given offical statement also that they are not capable to face China and demand for more import ..

At least in Army we have our basics made in our nation according to our needs ..

An IAF man at IDSA even referred to the import mania as being in a candy shop and buying as if there was no tomorrow, strategy be damned.

 

[Pandora]

can you post the link mate?

Prof. Prodyut Das: The Ails of the LCA

 

[abhi_the _gr8_maratha]

Prof. Prodyut Das: The Ails of the LCA

nothing is answered. He is just saying official figures are wrong, not proving it.

 

[ersakthivel]

Mr das replied our posts @ersakthivel

That looks as good as brazilian defence in their match against germany.

Basic empty weight of gripen C is given as 6250 Kg

tejas mk-1 comes in at 6500 Kg. So the difference is just 250 Kg. And Tejas has a significantly larger wing area and more volume for internal fuel.

SO there tejas mk-1 weighs just 250 Kg more than its very successful contemporary (just around 4 percent more), but has an engine that is 5 percent more powerful than gripen C. SO on the whole no reason to call it a heavy obsolete design that wont meet the specs.

For that 250 Ke extra basic empty weight it has a higher wing area giving it an advantageous lower wing loading which will help in Instantaneous turn regime.

The Thrust to weight ratios of gripen C and its contemporary tejas mk-1 in half fuel internal fuel weight and with just two close WVR missiles config are almost the same(both in the 1.07 region, if I am right).

So tejas mk-1 performance wont fall significantly from gripen C performance on the reason of weight alone. Tejas mk-1 has a max take off weight of 13.2 tons where the engine thrust and lift drops close to 12 percent as per your old estimate.

Gripen C whose max take off is given as 14 tons is for cold climate conditions. So it wont lift as much in indian hot climate conditions based on your estimate. So tejas mk-1 doesnot compare unfavourably with its contemporary Gripen C.

Prof. Prodyut Das: The Ails of the LCA

The above is my reply. Lets see the reply.

 

[ersakthivel]

He is on my ignore list, make some effort at your end.

Make some effort to read what is posted on at least the previous 5 pages of the thread before asking some one else to do the heavy lifting. This ignore list business wont sell here.

 

[ersakthivel]

ersakthivel already answered your post.. check above..

He thinks he is a higher being. So he wont read what is posted here. And he will use abusive language on people who counter him asking him to substantiate whatever his claims are.

 

[ersakthivel]

When Germans were interested in LCA-Tejas Trainer | idrw.org

The article states that german interest was a barter to TYPHOON selection in MMRCA. Will the author also admit that the SNECMA GTRE negotiations for K-10 kaveri are also of the same nature? Was it also a barter by french to induce rafale selection?

And had they backed out of TOT commitment for K-10 once rafale was selected?

Import loving journos are having a field day in thrashing indian products using the best possible creative writing pieces. How did the journo know that germans did not hve a genuine desire on buying tejas? The moment some DRDO guy says many nations are interested in buying Tejas , someone plays down such interests from abroad!!!!

Also I dont know which EADS gave consultancy to ADA for flight controls?

 

[ersakthivel]

Tejas Mk1 and Mk2 thread - Page 18

So there is no problem for you to show us that document.

So far the 2268 kg internal is the official value.

The Gripen uses ~200 kg for start-up, taxi, and take-off in AB.
A similar value of ~ 200 kg is used to climb to 40000 feet in military.
(The 100 seconds value for 33000 feet is in a max power climb only and will ill manyfold the related fuel-consumption!)
For an engagement including one minute in afterburner ~250 kg is used.
The reserve on its return has to be ~400 kg.
All that does leave ~1200 kg for cruise at Mach 0,8 , the sink and approach pattern for landing. One hour at Mach 0,8 or a distance of ~850 km consumes ~1100 kg of fuel.
Under typical mission conditions that give a combat radius of ~400 km on internal fuel.

LCA Tejas is capable of flying non- stop to destinations over 1700 km away (Ferry Range). It's Radius of Action is upto 500 km depending upon the nature and duration of actual combat.

So this finally settles all the debates on tejas vs any other single engined fighter comparison for ranges, I think.

So the rants expounded by all dumb eggsperts,

that while other fighters can fly for thousands of Kms carrying tons and tons of weapons ,

while tejas can not do so because of DRAG(citing Cemilac report and lack of empirical evidence!!!!) (even without knowing that this CEMILAC report has nothing to do with ranges on subsonic flight, and a recommendation for increasing supersonic topspeed !!!) is finally laid to rest I hope with Acher's post here.

http://profprodyutdas.blogspot.in/2014/06/the-ails-of-lca-professor-prodyut.html

Mother in laws of tejas who claim to have done fuel burn studies,

to prove that tejas is a draggy airframe,

with blunt aerodynamics ,

and a low aspect ratio airframe,

with an overweight 1300 KG airframe ,

and has a shorter range than its "contemporary " should note this.

 

[ersakthivel]

Broadsword: The Tejas LCA: improving performance with the current F-404 engine

Top HAL decision-makers pooh-pooh the IAF's contention that the LCA's air intakes are incorrectly designed, resulting in oxygen starvation and incomplete burning and, therefore, sub-optimal engine power from the F-404s. At the same time, however, steps are being taken to improve air intake, without getting into major redesign that could set back the programme by years. Instead, auxiliary air intakes are being provided on the sides of the Tejas engine housing --- similar to those on the Jaguar (see photos).

These auxiliary air intakes comprise of spring-loaded panels that open when engine suction is very high and provide an additional route for airflow into the engine intakes. As you can see in the photos, the spring-loaded panels can be pushed in by manual pressure.

At critical stages in the flight envelope, such as during take-off, rapid climb, sustained turn"¦ and in any case, when afterburners are on"¦ the heavy suction from the engines would open the auxiliary air intakes. When the demand for air goes down, such as in level flight, the auxiliary air intakes would close.

HAL designers aver that this would improve the engine performance only in some portions of the flight envelope. They say that during the most critical moments --- which are during sustained turns, in aerial combat --- the auxiliary air intakes would provide only marginally improved performance, if any at all.

A top HAL designer told me, "There is some merit in [the IAF's idea]"¦ the designers are considering it. There has been a debate for quite some time"¦ will it really improve to that extent. Where it really matters it may not give added thrust.. in other places it will give."

Nevertheless, the fitment of auxiliary air intakes is going ahead, partly because this does not require major re-engineering, nor will it delay the Tejas induction in any way. According to HAL, this will take six months to engineer; later LSPs will incorporate the auxiliary air intakes.

Tejas Light Combat Aircraft (LCA)

Wing Span 8.20 m
Length 13.20 m
Empty Weight 5500 kg
Max. takeoff weight 13,300 kg (29,100 lb)
Engine Prototype - GE F404-F2J3 turbofan rated at 18,097 lbst
Production - Kaveri GTX-35VS turbofan rated at 20,200 lbst
Fuel Capacity Internal fuel capacity - 3000 liters
Centerline and the two-inner hardpoints under each wing can carry five 800 liters fuel tanks
also has an in-flight refuelling probe
Maximum Range ?
Maximum Speed Mach 1.7
Service Ceiling 50,000 feet.
G Limits +9/-3.5
Armament internally mounted GSh-23mm twin barrel gun with 220 rounds of ammunition Seven external hardpoints, can carry air-to-air missiles, air-to-surface missiles, anti-ship missiles, rocket launchers and ECM pods
Maximum External Stores Load 4000kg (8818 lbs.)
Self Defence RWR system, jammer and chaff& flare dispensers.

Tejas as a total of 8 hardpoints: 1× beneath the port-side intake trunk, 6× under-wing, and 1× under-fuselage with a capacity of 4000 kg external fuel and ordnance. Any modern fighter is only as good as the weapons she can deliver on target. The Tejas is designed to carry a veritable plethora of air to air, air to surface, precision guided and standoff weaponry. In the air to air arena, the Tejas carries long range beyond visual range weapons, with highly agile high off-boresight missiles to tackle any close combat threat. A wide variety of air to ground munitions and an extremely accurate navigation and attack system allow it to prosecute surface targets over land or at sea with unparalleled accuracy, giving the Tejas true multi/swing role capability.

Broadsword: The Tejas LCA: improving performance with the current F-404 engine

The LCA's designers say that the removal of telemetry instrumentation, which is essential during flight testing, will bring the Tejas' weight down by as much as 300-400 kilos. Re-engineering some of the displays and sub-systems within the cockpit will lop off another 300 kilos; the weight reduction of 600-700 kilos is expected to allow the carriage of more weapons.

There is a lack of understanding about what the Tejas' weight is, since all kinds of figures are bandied about. Let me clarify: The 10.5 tons that I wrote about in my last post is the total weight of the Tejas, with full fuel on board; all 7 pylons fitted but not carrying weapons; and two outboard missiles being carried. The maximum payload of the Tejas is 3.5 tons"¦ carried on its pylons. This could be armament or external fuel tanks; if external fuel tanks are fitted, the weight of fuel will correspondingly bring down the weapons load carried.

But there's a catch! The maximum take-off weight of the Tejas is 13 tons. So if you load the maximum payload of 3.5 tons onto the 10.5 ton fighter, your weight of 14 tons is beyond the maximum take-off weight. So you'll have to shed one ton"¦ or either internal fuel or external fuel/armaments. That's what happens when a fighter's weight goes beyond what was originally planned.

So the reduction of 600-700 kilos may not actually go into making the Tejas more manoeuvrable. This shaved off weight may be made up by allowing the Tejas to carry (close to) its full capacity of external fuel-cum-armament.

(Empty weight + 2 R73 Missiles) 6500 kg + 3,000 kg internal fuel + 1,000 kg for 7 pylons = 10,500 kg (10.5 tons)

13,500 kg - 10,500 kg = 3,000kg for Weapons/External stores.

SO a removal of 700 Kg (400 Kg for telemetry equipment and 300 Kg for displays )will result in weapon load going upto 3.7 tons.

So the 6.5 tons whould be operational empty weight. In a similar way gripen too has 6.5 ton empty weight listed.

But when I pointed this out to mr das he says "SAAB Gripen weight is the operational empty weight. The LCa's is the basic empty weight.But that is missing or obfuscating the point on which I hinge my doubt.
The LCA, by ADA's own admission is 1300 kilos overweight.".

SO what is the correct position. Is the 6.5 tons is operational empty weight or basic empty weight of tejas mk-1?

SOme one should look into it and clarify this.

The above poster says speed mach 1.6, ceiling altitude reached. But mr. das says this speed was achieved in dive only. How can a plane dive from an altitude higher than its ceiling altitude to reach ceiling altitude with mach 1.6 speed? Then what is the meaning of the word ceiling altitude?

Also this poster says take off clean as 9.8 tons.

Generally take off clean means full fuel loaded, all pylons fitted with two outer most pylons carrying two R-73 missiles.

http://profprodyutdas.blogspot.in/2014/06/the-ails-of-lca-professor-prodyut.html

Only Mr das can explain it all with cap in hand ofcourse,

http://webcache.googleusercontent.c...org/exclusives/LCA/ACIG_Exclusives_Tejas.html

Antenna diameter 650 mm
Antenna gain 33 dB
TWT Power Output 6.5 kW (increaseable to 10 kW, 10% duty cycle)
Range 120 km against 2 sq.m RCS aerial target, >150 km for surface targets against sea clutter
All Up Weight (AUW) 130 kg
To keep the radar up to evolving standards, a new Advanced Signal and Data Processing Unit based upon Power-PC chips, has been developed to replace the older unit.

 

[ersakthivel]

Bharat Rakshak • View topic - LCA News and Discussions, 22-Oct-2013

Never seen this load-out before.

If that center line tank is a 1200 ltr tank, the payload is:
Fuel weight(3600 ltrs) = 2916 kgs + weight of 3 fuel tanks
Bombs (2*1000 lbs) = 908 kg
R-73 =210 kg
Total = 4034 kgs + weight of 3 fuel tanks.

Even if it is a 800 ltr tank the payload is:
Fuel weight(3200 ltrs) = 2592 kgs + weight of 3 fuel tanks
Bombs (2*1000 lbs) = 908 kg
R-73 =210 kg
Total = 3710 kgs + weight of 3 fuel tanks.

In both cases, it is above 3.5 Tons.

 

[ersakthivel]

http://carnegieendowment.org/files/dogfight.pdf
http://www.airfleet.ru/files/airfleet/Airfleet-2009-1.pdf

The article clearly says the reason for ADA not choosing canards is "it will lead to extra 0.76 meter fuselage length leading to more weight and extra RCS".

Strangle y Mr. DAS cites this lack of 0.76 meter fuselage to say that tejas mk-1 is aerodynamically blunt and inferior to its contemporary gripen!!!!

And it says that in initial phases the weight estimation was 6 tons and later optimistically changed to 5.5 tons based on composite assumptions!!!

But the article goes on to make some very colourful comments like,

cranked delta design was chosen with the view of increasing pilot visibility!!!!

the weapon load being just 1.5 tons(same as mig-21!!!) ,

TWR less than gripen(0.75 to 0.78) and all parameters including range not exceeding Mig-21!!!,

and eventhough ADA says it has reached mach 1.6, according to media reports(?!!?) it has never exceeded mach 1.4 and so on,,,,,,

It seems articles like this are the source of misinformation on tejas.

 

[ersakthivel]

The Tejas Debate Continues | TKS' Tales

here a poster named Vina clearly says that the 6.5 ton is operational empty weight of tejas. But Mr das keeps rather quiet!!!!

But many years later now mr. das raises the same operational vs basic empty weight point once again in the comment section The Ails of tejas article of his.

Vina counters Mr. Das with,

That explanation is doesn't seem plausible. There is a more plausible and simple one. William Green quoted the empty weight of A/B versions, and the C/D has seen the weight growth into 6.8 tons. That is exactly similar to the weight growth we saw with the earlier brochures of the LCA from 5600 kg to 6500kg . That said, let us go with the empty weights published by both the manufacturers. Gripen 6800 and LCA 6500 and assume that both say the same thing. That is something you keep beating the ADA about , but seem to forget the fact that what we are getting is a Gripen C/D equivalent version after the ASR revisions in 2004 or so. If you want to cut that slack for Gripen quoting William Green and ignoring the SAAB published figures, sure, but then you need to be consistent and cut the same slack here as well.

After this post by Vina Mr. das remains silent on basic vs operational empty weight calculations.

If he is so sure why he did not counter Vina with facts then in tkstales?

 

[ersakthivel]

Broadsword

Historic rise in DRDO budget, no additional funds for Rafale