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

[sathya]

Have the testing resumed or the fleet is still grounded.

Also Are the NP1 2 are grounded too?

Yes all are grounded including naval and trainer variants

After 2 months of grounding , test flights started with LSP4 alone.

 

[Sri]

Some People have done such research which you want.

A preliminary performance review of the Indian Light Combat Aircraft

Don't go with what some people is saying. Did you done the research, kindly show your research result.


what all planes -- Mk1 or Mk1a, Mk1 trainer, Mk1 naval ??


example is Lca tejas flying in banglore showing its mettle, and giving a *** burn in pakistani member like you.
Thats twin work aka multitasking. understand now Shoo..

What I heard is that IAF is not interested in the current IAF version of Tejas MK1 and want Naval tejas (With modified landing gear for Airforce, space optimised, weight reduced ) as the base for MK1A as this airframe is less draggy. So going with current MK1 will not be useful in any case for induction.
Any thoughts? Can anyone confirm?

 

[proud_indian]

What I heard is that IAF is not interested in the current IAF version of Tejas MK1 and want Naval tejas (With modified landing gear for Airforce, space optimised, weight reduced ) as the base for MK1A as this airframe is less draggy. So going with current MK1 will not be useful in any case for induction.
Any thoughts? Can anyone confirm?

this is what mr. Prasun K. sengupta is saying

 

[knight11]

What I heard is that IAF is not interested in the current IAF version of Tejas MK1 and want Naval tejas (With modified landing gear for Airforce, space optimised, weight reduced ) as the base for MK1A as this airframe is less draggy. So going with current MK1 will not be useful in any case for induction.
Any thoughts? Can anyone confirm?

Where did you heard this ? and by whom ?
Navy want's more powerful power plant for flying with the useful load from the carrier. Modified landing gear for taking the impact of the crash landing on the carrier, more height due to short takeoff. Current MK1 was more than enough to fulfill the airforce requirement aka replacement of the Mig-21, but IAF with unknown reason wants all certification, and best of the qualities they gathered from the various brouchers they collected from various fighter planes. They could not wait for the block upgrade and want to have all the capabilities from the day one for the indigenous fighter plane, but don't show such lineancies toward the exported jets such as jaguar, mirrage 2k, and MKI. Ironically, the features they want will make tejas the most featureful fighter planes of the IAF including HMDS, maws, EW suites, netcentric, high altitude/hotweather/cold weather certified, naval, trainer versions.

 

[Sri]

Where did you heard this ? and by whom ?
Navy want's more powerful power plant for flying with the useful load from the carrier. Modified landing gear for taking the impact of the crash landing on the carrier, more height due to short takeoff. Current MK1 was more than enough to fulfill the airforce requirement aka replacement of the Mig-21, but IAF with unknown reason wants all certification, and best of the qualities they gathered from the various brouchers they collected from various fighter planes. They could not wait for the block upgrade and want to have all the capabilities from the day one for the indigenous fighter plane, but don't show such lineancies toward the exported jets such as jaguar, mirrage 2k, and MKI. Ironically, the features they want will make tejas the most featureful fighter planes of the IAF including HMDS, maws, EW suites, netcentric, high altitude/hotweather/cold weather certified, naval, trainer versions.

I have heard this from HAL Chaiwala . also this is mentioned by Prasun. The issue is that IAF version is too draggy and the airframe needs significant aerodynamic modifications to counter this. whereas the Navy version ( with gods grace) has been made less draggy, and its sub systems are also more or less tested. So IAF wants the Navy airframe (Since this is already developed and no extra time is needed to design) take out the navy landing gear, arrester hook etc and make it suited for airforce.
IAF was thrilled itseems when they saw LCA navy's performance at Goa tests and were convinced that the airforce version should be based on this.
IAF wants the above said modifications which would take 1 year and do the flight testing, So that aircraft is available by mid 2017. Also the landing gear discussion which was discussed by Raju meant this itseems when he proposed MK1A to IAF.
This is Chaiwala info, So this may or may not be true

 

[Sri]

I have heard this from HAL Chaiwala . also this is mentioned by Prasun. The issue is that IAF version is too draggy and the airframe needs significant aerodynamic modifications to counter this. whereas the Navy version ( with gods grace) has been made less draggy, and its sub systems are also more or less tested. So IAF wants the Navy airframe (Since this is already developed and no extra time is needed to design) take out the navy landing gear, arrester hook etc and make it suited for airforce.
IAF wants the above said modifications which would take 1 year and do the flight testing, So that aircraft is available by mid 2017. Also the landing gear discussion which was discussed by Raju meant this itseems when he proposed MK1A to IAF.

I had document ( unable to trace it) was created by NAL which specifies the changes needed in IAF Tejas to canopy, wings etc to reduce the drag. this will improve the aerodynamics and give 20% better performance in transonic regime and also in range.

This is first doc on changes: http://drdo.gov.in/drdo/pub/dss/2009/main/2-CEMILAC.pdf
There is also another doc which specifically speaks about canopy changes proposed.

What IAF is asking is instead of doing all these changes to canopy etc. they want Navy version (which is already developed with these changes and can be tweaked to IAF needs)

The Biggest Concerns of IAF with Tejas were Drag, Weight, Maintenance.
Drag: this is addressed with LCA Navy which is a aerodynamically refined model and can be modified for IAF needs.
Weight : this is a progressive task and can be addressed to some extent with rearranging sub systems.
Maintenance: This needs rearranging sub-systems so that they can be accessed easily.

Since HAL and ADA were not ready to do these earlier and was giving jugaad solutions IAF jumped on to MK2. Parikar seems to have understood this problem and tried to find best solution under the curcumastances where in everyone is happy.



I could trace this doc: http://www.nal.res.in/cfdsympo/cfdfullpaperfinal/Influence of Canopy shape on the supersonic drag of a generic Fighter Aircraft.pdf

 

[sathya]

What the heck ?

It looks like IAF is pretty poor in managing anything compared to navy

It better navy does that job for IAF

Someone was saying, canopy changes proposed will increase 6% performance

 

[Sri]

What the heck ?

It looks like IAF is pretty poor in managing anything compared to navy

It better navy does that job for IAF

Someone was saying, canopy changes proposed will increase 6% performance

Well IAF never had a say itseems (unlike Navy) and IAF was kept away from all decisions till 2007. Once they were on-board after 2007 things started changing rapidly. Since no one was listening to them, IAF was so frustrated that they tried to take over the whole HAL, which anyway did not materialize.
By the way IAF did have a design division in 1960s which was taken away and merged with HAL. So IAF was always an outsider who has to accept the product even when they do not have a proper say.

The second PDF which I have attached is the source for canopy changes needed and it says 20% improvement. This is already incorporated in LCA Navy

 

[knight11]

What IAF is asking is instead of doing all these changes to canopy etc. they want Navy version (which is already developed with these changes and can be tweaked to IAF needs)

It was clear that for naval tejas, F-414 was needed, to be able to takeoff and fly with the useful wt for the carrier operation.
IAF took the Idea for the 414 for mk2 for more better aerodynamic charasterstic in STR, ITR, rateof climb and AoA.

I have heard this from HAL Chaiwala . also this is mentioned by Prasun.

Prasun is not an aerodynamic expert or the official spoke person. What he is doing is expressing his concerned.
There is no perfect design for the plane in the world, but the plane is the best choice we make. Now we don't deny that LCA tejas somehow don't fulfill IAF ASQR (which she changed twice in the development timeframe) specially related to STR. While designing LCA tejas ADA could choose simply Su30 MKI design straightforward instead of Delta, tailless design but there are other requirements to fulfill other wise all the planes in the world would look like the same. The design for LCA was choosen to fulfill these requirement like size constrain, High altitude short runway capablity with full load.

What Cemilac is doing is that she proposed various improvement steps like nose cone plug extension and pylon reshaping.which can reduce the drag at sea level which is area of concern. R&D is the continuous process and there is no hard and fast rule for that and the improvement should continue as a process. Regarding LCA which was designed around Kaveri engine, now the powerplant is F404 which has less power thrust, so the reduction of drag and weight becomes more important. These design changes means that LCA needs more polishing, and big changes of airframe is not economical valid option now with more delay.

Naval LCA design improvement is for the carrier operation like cannard for lifting its nose during takeoff and landing, and no relation with the IAF design.

For you just the reduction of the weight of the LCA, to its original wt l.e 5500 KG will do the wonders and would be able to fulfill the IAF ASR requirement, pls refer milspec post how it can be achieed, just few pages behind.

Thanks and regards

 

[Sri]

It was clear that for naval tejas, F-414 was needed, to be able to takeoff and fly with the useful wt for the carrier operation.
IAF took the Idea for the 414 for mk2 for more better aerodynamic charasterstic in STR, ITR, rateof climb and AoA.


Prasun is not an aerodynamic expert or the official spoke person. What he is doing is expressing his concerned.
There is no perfect design for the plane in the world, but the plane is the best choice we make. Now we don't deny that LCA tejas somehow don't fulfill IAF ASQR (which she changed twice in the development timeframe) specially related to STR. While designing LCA tejas ADA could choose simply Su30 MKI design straightforward instead of Delta, tailless design but there are other requirements to fulfill other wise all the planes in the world would look like the same. The design for LCA was choosen to fulfill these requirement like size constrain, High altitude short runway capablity with full load.

What Cemilac is doing is that she proposed various improvement steps like nose cone plug extension and pylon reshaping.which can reduce the drag at sea level which is area of concern. R&D is the continuous process and there is no hard and fast rule for that and the improvement should continue as a process. Regarding LCA which was designed around Kaveri engine, now the powerplant is F404 which has less power thrust, so the reduction of drag and weight becomes more important. These design changes means that LCA needs more polishing, and big changes of airframe is not economical valid option now with more delay.

Naval LCA design improvement is for the carrier operation like cannard for lifting its nose during takeoff and landing, and no relation with the IAF design.

For you just the reduction of the weight of the LCA, to its original wt l.e 5500 KG will do the wonders and would be able to fulfill the IAF ASR requirement, pls refer milspec post how it can be achieed, just few pages behind.

Thanks and regards

The changes needed for drag reduction are mentioned in the 2nd PDF which I have attached. Now does HAL/ADA is going to make these changes to LCA MK1 was the question and they were not planning for MK1, therefore IAF was not interested in taking many examples of MK1 and were insisting on MK2. What I understood from the talk is that drag is the differentiation here - if the drag is reduced then thrust can be felt adequate.

The other design which is already available with respect to airframe shaping is LCA Navy MK1 which has refined aerodynamics( I am not speaking about Cannards, and speaking about nose design and canopy). so IAF wants this shaping for IAF version.
With respect to Weight this is going to be a progressive affair, so not much emphasis is given to this for MK1A. Hope I am clear.

 

[satishkumarcsc]

Sense prevailing at last.

Always wanted the Navy version to be taken up for MK2 as it will save a lot more time and money instead of building a new MK2. The world is moving on to 5th generation and designing a brand new 4th generation aircraft now is stupidity.

 

[GURU DUTT]

I have heard this from HAL Chaiwala . also this is mentioned by Prasun. The issue is that IAF version is too draggy and the airframe needs significant aerodynamic modifications to counter this. whereas the Navy version ( with gods grace) has been made less draggy, and its sub systems are also more or less tested. So IAF wants the Navy airframe (Since this is already developed and no extra time is needed to design) take out the navy landing gear, arrester hook etc and make it suited for airforce.
IAF was thrilled itseems when they saw LCA navy's performance at Goa tests and were convinced that the airforce version should be based on this.
IAF wants the above said modifications which would take 1 year and do the flight testing, So that aircraft is available by mid 2017. Also the landing gear discussion which was discussed by Raju meant this itseems when he proposed MK1A to IAF.
This is Chaiwala info, So this may or may not be true

what my "chirriya" told me is that DM & PM & IAF top brass responsible for LCA programme have agrred to modify the current tejas by

1.redisigning a few parts in its body

2. slight modifictaions in its wings & air intake (i personally want to see DSI enabelled F/A-18 E F type)

3.repakaging the avionicks after taking owt all testing & tellmatory insturments and there housings and harnesses

4.putting a new AESA based radar & EW suite and a new chaffs and flairs dispensing system

5.newlight and modified landing gear & rearanging and taking owt all unecesary counterwieghts

6.new version of compact IFR probe and oxygen genrating system

and yes DM wants to give more effort and money into R&D of AMCA & AURA than MK2 .. i may be wrong

 

[Sri]

what my "chirriya" told me is that DM & PM & IAF top brass responsible for LCA programme have agrred to modify the current tejas by

1.redisigning a few parts in its body

2. slight modifictaions in its wings & air intake (i personally want to see DSI enabelled F/A-18 E F type)

3.repakaging the avionicks after taking owt all testing & tellmatory insturments and there housings and harnesses

4.putting a new AESA based radar & EW suite and a new chaffs and flairs dispensing system

5.newlight and modified landing gear & rearanging and taking owt all unecesary counterwieghts

6.new version of compact IFR probe and oxygen genrating system

and yes DM wants to give more effort and money into R&D of AMCA & AURA than MK2 .. i may be wrong

Hi, Are you sure about obogs? as I haven't heard about this. When I asked about this they said the fighter is for very short distance and obogs may not add much value. ofcourse this will improve the turnaround time

 

[knight11]

Hi, Are you sure about obogs? as I haven't heard about this. When I asked about this they said the fighter is for very short distance and obogs may not add much value. ofcourse this will improve the turnaround time

How much short distance. LCA tejas can fly without drop tank upto 1700KM. With 3 drop tanks up to 3200KM, and with aerial refuel tank ---??km. By the way obogl does help in reducing the wt during the takeoff.

I will answer to your links provided later, right now I am little bit busy.

 

[Sri]

How much short distance. LCA tejas can fly without drop tank upto 1700KM. With 3 drop tanks up to 3200KM, and with aerial refuel tank ---??km. By the way obogl does help in reducing the wt during the takeoff.

I will answer to your links provided later, right now I am little bit busy.

The max normal duration of the flight is around 1.5 to 2 hours since it will be primarily used for air patrolling and point defense. So this is what I believe they meant. of-course if something like this can be added by 2018 to MK1A then it would always be a pleasant surprise . I agree with your point that every design is a compromise and so is Tejas. but what I was speaking about is refinement not design.

PS. The sources I spoke to could be wrong or I might have understood it wrong, anyway its good for discussion.