ADA Tejas (LCA) News and Discussions

[ersakthivel]

for correct time lines
LCA Tejas, MIG-21s and IAF - Opportunity missed - hope it is not lost!

LCA was supposed to enter service in 1990"²s, when Ajeets were scheduled to be retired. Procedural delay's, infrastructure set up and other factors delayed the project till late 1990"²s. Once Full Scale Engineering Development (FSED) Phase-I of LCA was sanctioned in June 1993 , the Defence Research Development Organisation's and Aeronautical Development Agency ( DRDO and ADA), flew the first prototype in 2001.

In 2004, IAF formulated the final Air Staff Requirement (ASR), which mirror the requirements of a Mig -21 ++ replacement. The matter is complicated as the power requirement surged and a higher thrust engine is now required. 2004 ASR was in effect counter to the very philosophy of LCA project. It basically makes it a bigger and heavier fighter.

 

[p2prada]

Naval LCA set for carrier compatibility tests | idrw.org

N-LCA may start flying soon.

In a year or two we will need a dedicated thread for N-LCA in the Indian Navy section.

 

[rvjpheonix]

@p2prada, @Twinblade @ersakthivel . What does this news about EW imply? Isn't the mk1 supposed to carry EW Pod outside on a special pylon? Now they are moving it inside? Isn't the mk2 going to have an internal EW system and not the mk1? Or are they trying something like a dedicated jammervlike the growler?

 

[ersakthivel]

@p2prada, @Twinblade @ersakthivel . What does this news about EW imply? Isn't the mk1 supposed to carry EW Pod outside on a special pylon? Now they are moving it inside? Isn't the mk2 going to have an internal EW system and not the mk1? Or are they trying something like a dedicated jammervlike the growler?

PV-1 was being modified for dedicated EW role as per AJAI SHUKLA's blog. We need more clarity whether this recent article specifies a add on EW suit for regular MK-1 or a modified version of MK-1.Until that is known we can not come to any conclusion

 

[p2prada]

What does this news about EW imply?

Hmm, it means LCA's EW suite will be put to the test.

Isn't the mk1 supposed to carry EW Pod outside on a special pylon? Now they are moving it inside?

Pod is a definite. But it is not clear whether the RWJ is internal. There were old talks of development of RWJs. We will have to wait and see whether an internal jammer will be part of the final FOC aircraft.

In the article, adding the terms radar warning receiver and radar warning jammer doesn't make sense. So, it could be a case of bad reporting. RWJ is a RWR with jamming capability.

Isn't the mk2 going to have an internal EW system and not the mk1?

Mk2 will definitely have an internal RWJ.

Or are they trying something like a dedicated jammervlike the growler?

Growler is an entirely different level of EW. LCA's EW kit is only a self protection suite and is common in most aircraft. Spectra is also a self protection suite.

 

[Sridhar]

http://trishul-trident.blogspot.in/2013/10/clearing-mist-on-airborne-ew-suites.html

 

[rvjpheonix]

@Decklander sir @p2prada what is the actual endurance of the lca? The endurance and range is a function of fuel fraction and drag imposed isn't it? The lca has a high fuel fraction and the delta configuration is said to have low drag at high altitude and higher speeds. Still it is said to have a much smaller combat radius than the gripen. Why? Do we know how much fuel the lca burns at its cruise speeds in an hour. @p2prada how did you get the 40 min figure. Any link? @ersakthivel

 

[p2prada]

@Decklander sir @p2prada what is the actual endurance of the lca?

40 min on internal, 1 hour with external.

The lca has a high fuel fraction and the delta configuration is said to have low drag at high altitude and higher speeds.

LCA does not have a particularly high fuel fraction. It is a light fighter after all.

Still it is said to have a much smaller combat radius than the gripen. Why?

It should be the same.

A later block F-16 barely does a little over an hour with 3.1 tonnes of fuel in its belly.

Do we know how much fuel the lca burns at its cruise speeds in an hour.

It should be available somewhere. I don't know it.

@p2prada how did you get the 40 min figure. Any link? @ersakthivel

The Hindu : National : Tejas flight, with drop tanks, successful

While the internal tanks allow the Tejas to perform a 40-minute sortie, the drop tanks will increase its endurance by almost an hour.

Slightly reducing Mirage-2000 specs will give you an idea about LCA. These are Dassault's actual specs for M-2000.
Flight data

Fuel consumption for the aircraft are at max power too. That's full dry power. It should be a little better for LCA since full power is not being used on it and the engine itself is way better than the ones on Mirage-2000.

 

[Decklander]

The fuel flow is a direct function of thrust. Higher the load, more is the thrust reqd so higher is the consumption. As stated, at higher altitudes the thrust needed is low as the density of air is less and drag is a function of IAS. So for same load, you will have less consumption at high altitude. The radius of action data for a fighter is normally given for max load, internal fuel only for Lo-LO-LO sortie with 3 min max military power at sea level over target.
As you can see, this will change based on config and external fuel tanks.

 

[ersakthivel]

@Decklander sir @p2prada what is the actual endurance of the lca? The endurance and range is a function of fuel fraction and drag imposed isn't it? The lca has a high fuel fraction and the delta configuration is said to have low drag at high altitude and higher speeds. Still it is said to have a much smaller combat radius than the gripen. Why? Do we know how much fuel the lca burns at its cruise speeds in an hour. @p2prada how did you get the 40 min figure. Any link? @ersakthivel

Endurance has nothing to do with a fighter being light or heavy or how much drag is there.

Endurance depends upon the percentage of fuel inside divided by the loaded weight for normal configuration of mission.

With heavy weapon load all fighters have low endurance time. If the weapon load is heavy all fighters have low endurance
LCA may carry 30 percent less fuel than Mirage-2000. But tejas's weight at that full external fuel config is also less than the Mirage-2000.

because the 6000 lit fuel of tejas propels a fighter which weighs a few ton lesser than Mirage-2000 which carries 9700 lit fuel. So that evens out.

With full weapon load and full fuel the Mirage-2000 weighs (MTOW) 17 tons, but for the same config Tejas weighs only 13,5 tons (MTOW)

Also lift to drag ratio and the specific fuel consumption of the engine also must be taken into consideration. the Ge F-404 IN20 is more fuel efficient than ordinary GE-404 series and Ge-414 IN S6 is more fuel efficient (has lesser SFC) than the Ge-404 IN 20 for the thrust it provides.

if you want to know more despite being a twin engined fighter the Mig-29 is considered a lesser range fighter. Why because it lugs more of fighter weight for the fuel it carries.

So it is not such a straight forward 30 percent less fuel means thirty percent less range argument.

It is much more complex calculation.Also if fighters are loaded to their full capacity they will most likely fly like cargo plane. So most of the time fighters carry only optimum design loads to get good performance.

 

[venkat]

erSakthvivelsir,ot ofcourse ...what is this assymetry in ijt which is stopping. the spin trials?can't this be corrected?can u pressnt an aerodynamic analysis if u. have time?

 

[rvjpheonix]

Endurance has nothing to do with a fighter being light or heavy or how much drag is there.

Endurance depends upon the percentage of fuel inside divided by the loaded weight for normal configuration of mission.

With heavy weapon load all fighters have low endurance time. If the weapon load is heavy all fighters have low endurance
LCA may carry 30 percent less fuel than Mirage-2000. But tejas's weight at that full external fuel config is also less than the Mirage-2000.

because the 6000 lit fuel of tejas propels a fighter which weighs a few ton lesser than Mirage-2000 which carries 9700 lit fuel. So that evens out.

With full weapon load and full fuel the Mirage-2000 weighs (MTOW) 17 tons, but for the same config Tejas weighs only 13,5 tons (MTOW)

Also lift to drag ratio and the specific fuel consumption of the engine also must be taken into consideration. the Ge F-404 IN20 is more fuel efficient than ordinary GE-404 series and Ge-414 IN S6 is more fuel efficient (has lesser SFC) than the Ge-404 IN 20 for the thrust it provides.

if you want to know more despite being a twin engined fighter the Mig-29 is considered a lesser range fighter. Why because it lugs more of fighter weight for the fuel it carries.

So it is not such a straight forward 30 percent less fuel means thirty percent less range argument.

It is much more complex calculation.Also if fighters are loaded to their full capacity they will most likely fly like cargo plane. So most of the time fighters carry only optimum design loads to get good performance.

You're just saying what I am saying. I never said that range depends on total fuel. I am saying that it depends on FF. Thus the question. I am asking for numbers here. The tejas has a good ff and SFC with the 404. So its endurance of just 40 mins is a little surprising. I am not pressing you though its alright of you don't have the numbers.

 

[mahesh]

What if the Engline of Tejas GE f 404 and GE f 414 has thrust vectoring nozzle, will it increase the maneuvering abilities ?

 

[shiphone]

that's oK...I see...we'd better back to the LCA topic...

 

[Decklander]

Delta design and Tailless Delta designs are most optimum for high subsonic cruise regimes and they provide least drag in those conditions. The problem arises at high AOA to get max CL. The drag rise compared to other designs is higher for Delta designs in those regimes.
Infact even I am surprised to read that tailless delta design has higher subsonic drag.

 

[TrueSpirit]

Infact even I am surprised to read that tailless delta design has higher subsonic drag.

Sir, higher subsonic or supersonic ?

Or you meant: At high AOA during high subsonic cruise regime ?

 

[uss]

An old video on LCA in its early days of testing from facebook. Please ignore if already posted.

Wings of the Future
https://www.facebook.com/photo.php?v=3392552893389&set=vb.103329156428208&type=2&theater

 

[uss]

DRDO to export sonars to Myanmar soon

DRDO to export sonars to Myanmar soon - The Hindu

On Tejas, he said the aircraft in Mark-1 configuration would get full initial operational clearance by this year-end, and would brace for final operational clearance in 2014. Its series production had begun and induction of the first series production aircraft into the Air Force would also take place next year.

 

[Decklander]

Sir, higher subsonic or supersonic ?

Or you meant: At high AOA during high subsonic cruise regime ?

I meant drag associated with high subsonic speed.

 

[TrueSpirit]

I meant drag associated with high subsonic speed.

I do not get it, Sir. You had said in the same post:

Delta design and Tailless Delta designs are most optimum for high subsonic cruise regimes and they provide least drag in those conditions

So, Tailless Delta designs are optimum for high subsonic cruise regimes or not optimum ?