ADA Tejas (LCA) News and Discussions

[sathya]

]

Note the tails, EW installed..

why there is no horizontal fins in vertical tail in the last two aircrafts ?

 

[sathya]

Out of 200 "requests for action" --- which are suggestions from IAF pilots and technicians for design changes that would ease maintenance --- most have already been implemented in tejas MK-1. Just 12-15 remain for implementing in the Tejas Mark II.

hi, u know the source article for it ? can you post the link?

 

[Kunal Biswas]

Must be older once...

why there is no horizontal fins in vertical tail in the last two aircrafts ?

 

[sathya]

also it was said F404 engine won't have enough power for EW...

did something happened or its just an antenna ?

 

[ersakthivel]

hi, u know the source article for it ? can you post the link?

Broadsword: Designers insist Tejas will belie all sceptical questioning
ADA chief's interview to ajai shukla of broadsword blog.

 

[ersakthivel]

So this thing cant dog fight? How true is the statement? Still problems with AoA?

It can do close combat.The problem with AOA is the spin test to check the near stall speed behaviour of he aircraft is not conduced.
ADA is very cautious on this because it has fewer crafts ,so it is taking consultancy from eads for this purpose.Until the spin recovery test where the aircraft simulates stall condition and how it recovers from it as per it's fly by wire software, max AOA cannot be pulled.This is ada's point of view for testing the aircraft within the 85 percent of the flight envelope.Only after the flight envelope os opened fully after the spin recovery test ,can tejas pull max aoa as it is the norm in any global flight test program.

Also higher powered GE engine for series production aircraft is needed for further reaching max AOA as tejas's max speed ,max take off weight, ,and all other specs are heavier due to revised iaf requirements.



http://ajaishukla.blogspot.in/2011/04/designers-insist-tejas-will-belie-all.html
You can read ADA chief's interview in the above link.

 

[ersakthivel]

Tejas - Feature - The Light Combat Aircraft Story by Air Marshal MSD Wollen (Retd)

THE ABOVE LINK IS A MUST READ FOR ANYONE TO UNDERSTAND THE TIMELINES, MAGNITUDE OF THE TECH CHALLENGES FACED AND WHAT WAS ACHIEVED IN TEJAS PROGRAM

Most of the misconception regarding tejas can be cleared by the through read of the above article by AIR MARSHAL ASD WOOLLEN WHO WAS THE HAL CHAIRMAN DURING THE CRITICAL PERIOD OF 1984 to 89 when the lca program was conceptualized.

The LCA is tailless with a double-sweep delta wing. Its wing span is 8.2 m, length 13.2 m, height 4.4 m. TOW clean 8.500 kg, MTOW 12500kg. It will be super-sonic at all altitudes, max speed of M 1.5 at the tropopause. Specific excess power and g-over load data has not been published. Maximum sustained rate of turn will be 17 deg per sec and maximum attainable 30 deg per sec.

According to him the above is the original ASR.
G loads,excess power data was not there even in this link.

During early flight development, the TD aircraft will be powered by a single GE F404 F2J3 engine (7,250 kg reheat thrust).

then specs of lca now is

Tow clean -9 ton ,
Mtow-14.5 ton,
top speed-1.8 mach at altitudes,1.2 at sea level,
AoA-28 degree,

SO these specs cannot be achieved by the lower powered GE engine that is currently onLCA LSPs,
It needs a higher powered engine for achieving the specs.

From 1983 to 1993 nothing much happene on the TEJAS,
The 500 cr released before 1993 was used for infra set up and Project definition,(all defined specs changed later)
Only after Funding of Tds started in 1990s did any practical work commenced on the project.

Salient engine features include the 3 stage fan; 6 stage HP compressor with variable geometry IGV, I and II stators; annular combustion chamber; cooled single stage HP and LP turbines; modulated after-burner; fully variable, convergent-divergent nozzle; length 3490 mm; max diameter 910 mm; dry thrust 52 kN; reheat thrust 81 kN; thrust weight ratio 7.8. The 'Achilles heel; in the successful development of the LCA, in the opinion of this author, is the Kaveri engine.

The above is the specs of kaveri engine.

Around 75 kn thrust is now achieved with thrust weight ratio of around 7 in 20 years ,typical of any engine developmental program.So what was refered to as achilies heels of tejas has been solved.The problem is tejas specs have gone well past the specs of the engine due to developments in modern fighter design.

Tweaking the engine for 80 plus kn is not impossible.But tejas needs 90 pluskn engine in it's current avathar.That's why JV with snecma is proposed.

Note the AL-31 FP has the same thrust to weight ratio of 7.8 (it is on the sukhoi,I think but I am not sure)that was aimed for GTRE KAVERI
And more or less it has been achieved.
The chinese WS engines also has the same thrust to weight ratio of 7.8 .

So india is not not lagging behind even in engine techlevel,once all the small niggling problems with K-9 are solved.

the blind thrust figure doesnot say anything regarding tech level of engines.It is the TWR figure that determines the engine tech level.In which now we have advanced to a significant extent.That's why the PRATT &WHITNEY team which examined the engine said it was a world class engine and further improvements in thrust level is possible.

Also the SNECMA team too studied the engines and said it can be uprated to 90 plu KN.

In the late eighties India's aircraft Industry was not as advanced as Sweden's; and yet India follows a more arduous design/development route for its LCA, compared to Sweden for its JAS-39 Gripen. The Gripen embodied a far higher percentage of foreign, off-the-shelf technology, including its RM-12 engine (improved GE F404). France (Dassault Aviation) built and exhaustively flew a demonstrator aircraft (Rafale-A) before embarking on construction of Rafale prototypes.


Over 2,000 flights were completed by September 1994 when first Flight of a production Rafale was still 20 months away. At that point of time, Dassault Aviation had built or flown 93 prototypes, of which at least fifteen went into production after sixteen years elapsed from 'first-metal-cut' of the Rafale demonstrator to entry into service. Current plans for the LCA is ten years. And what of India's past record?

It is unlikely that the LCA will attain initial operational clearance (IOC) before 2010.When it is achieved, it will be an industrial success of magnificent proportion, and is sure to receive the acclaim it deserves.

this is the prophetic conclusion of the author who was the chairman of HAl at that time and it was proved conclusively right.
Note his words--When it is achieved, it will be an industrial success of magnificent proportion, and is sure to receive the acclaim it deserves

So it will clear most of the misconception regarding tejas programs time lines, capabilities.
This is as authentic as it gets.

 

[ersakthivel]

Re: ADA Tejas (LCA) - III

Tejas - Feature - The Light Combat Aircraft Story by Air Marshal MSD Wollen (Retd)

THE ABOVE LINK IS A MUST READ FOR ANYONE TO UNDERSTAND THE TIMELINES, MAGNITUDE OF THE TECH CHALLENGES FACED AND WHAT WAS ACHIEVED IN TEJAS PROGRAM

Most of the misconception regarding tejas can be cleared by the through read of the above article by AIR MARSHAL ASD WOOLLEN WHO WAS THE HAL CHAIRMAN DURING THE CRITICAL PERIOD OF 1984 to 89 when the lca program was conceptualized.

The LCA is tailless with a double-sweep delta wing. Its wing span is 8.2 m, length 13.2 m, height 4.4 m. TOW clean 8.500 kg, MTOW 12500kg. It will be super-sonic at all altitudes, max speed of M 1.5 at the tropopause. Specific excess power and g-over load data has not been published. Maximum sustained rate of turn will be 17 deg per sec and maximum attainable 30 deg per sec.

According to him the above is the original ASR.
G loads,excess power data was not there even in this link.

During early flight development, the TD aircraft will be powered by a single GE F404 F2J3 engine (7,250 kg reheat thrust).

then specs of lca now is

Tow clean -9 ton ,
Mtow-14.5 ton,
top speed-1.8 mach at altitudes,1.2 at sea level,
AoA-28 degree,

SO these specs cannot be achieved by the lower powered GE engine that is currently onLCA LSPs,
It needs a higher powered engine for achieving the specs.

From 1983 to 1993 nothing much happene on the TEJAS,
The 500 cr released before 1993 was used for infra set up and Project definition,(all defined specs changed later)
Only after Funding of Tds started in 1990s did any practical work commenced on the project.

Salient engine features include the 3 stage fan; 6 stage HP compressor with variable geometry IGV, I and II stators; annular combustion chamber; cooled single stage HP and LP turbines; modulated after-burner; fully variable, convergent-divergent nozzle; length 3490 mm; max diameter 910 mm; dry thrust 52 kN; reheat thrust 81 kN; thrust weight ratio 7.8. The 'Achilles heel; in the successful development of the LCA, in the opinion of this author, is the Kaveri engine.

The above is the specs of kaveri engine.

Around 75 kn thrust is now achieved with thrust weight ratio of around 7 in 20 years ,typical of any engine developmental program.So what was refered to as achilies heels of tejas has been solved.The problem is tejas specs have gone well past the specs of the engine due to developments in modern fighter design.

Tweaking the engine for 80 plus kn is not impossible.But tejas needs 90 pluskn engine in it's current avathar.That's why JV with snecma is proposed.

Note the AL-31 FP has the same thrust to weight ratio of 7.8 (it is on the sukhoi,I think but I am not sure)that was aimed for GTRE KAVERI
And more or less it has been achieved.
The chinese WS engines also has the same thrust to weight ratio of 7.8 .

So india is not not lagging behind even in engine techlevel,once all the small niggling problems with K-9 are solved.

the blind thrust figure doesnot say anything regarding tech level of engines.It is the TWR figure that determines the engine tech level.In which now we have advanced to a significant extent.That's why the PRATT &WHITNEY team which examined the engine said it was a world class engine and further improvements in thrust level is possible.

Also the SNECMA team too studied the engines and said it can be uprated to 90 plu KN.

In the late eighties India's aircraft Industry was not as advanced as Sweden's; and yet India follows a more arduous design/development route for its LCA, compared to Sweden for its JAS-39 Gripen. The Gripen embodied a far higher percentage of foreign, off-the-shelf technology, including its RM-12 engine (improved GE F404). France (Dassault Aviation) built and exhaustively flew a demonstrator aircraft (Rafale-A) before embarking on construction of Rafale prototypes.


Over 2,000 flights were completed by September 1994 when first Flight of a production Rafale was still 20 months away. At that point of time, Dassault Aviation had built or flown 93 prototypes, of which at least fifteen went into production after sixteen years elapsed from 'first-metal-cut' of the Rafale demonstrator to entry into service. Current plans for the LCA is ten years. And what of India's past record?

It is unlikely that the LCA will attain initial operational clearance (IOC) before 2010.When it is achieved, it will be an industrial success of magnificent proportion, and is sure to receive the acclaim it deserves.

this is the prophetic conclusion of the author who was the chairman of HAl at that time and it was proved conclusively right.
Note his words--When it is achieved, it will be an industrial success of magnificent proportion, and is sure to receive the acclaim it deserves

So it will clear most of the misconception regarding tejas programs time lines, capabilities.
This is as authentic as it gets.

 

[ersakthivel]

http://defenceforumindia.com/forum/...d-working-third-stealth-fighter-report-2.html

Post no-16 by weg

The concept seems to be, build an ultra stealthy, low cost UAV which can work autonomously or in squadron (possible with a Eurofighter or Rafael in command). Low cost comes from the Rolls-Royce Adour engine as used in the BAe Hawk and Jaguar.

The aircraft will probably cost 1/5 the price (~$20m) of a EF or Rafael and less than half the hourly cost to operate. Being unmanned you could have two aircraft on point, with their radar shining on approaching stealth aircraft to receive reflections from the side aspect, while others could use their all aspect, ultra stealth (better than any manned aircraft). The manned fighter could loiter behind with its radar switched off (stealth aircraft cannot use their Radar..) ready to pick off whatever makes it past the drones.

For anbody interested in how stealth UCAVs like AURA or EW aircrafts working in combination with 4th gen fighters against 5th gen stealth this will give some clarifiction

 

[ersakthivel]

Re: ADA Tejas (LCA) - III

http://defenceforumindia.com/forum/...d-working-third-stealth-fighter-report-2.html

Post no-16 by weg

The concept seems to be, build an ultra stealthy, low cost UAV which can work autonomously or in squadron (possible with a Eurofighter or Rafael in command). Low cost comes from the Rolls-Royce Adour engine as used in the BAe Hawk and Jaguar.

The aircraft will probably cost 1/5 the price (~$20m) of a EF or Rafael and less than half the hourly cost to operate. Being unmanned you could have two aircraft on point, with their radar shining on approaching stealth aircraft to receive reflections from the side aspect, while others could use their all aspect, ultra stealth (better than any manned aircraft). The manned fighter could loiter behind with its radar switched off (stealth aircraft cannot use their Radar..) ready to pick off whatever makes it past the drones.

For anbody interested in how stealth UCAVs like AURA or EW aircrafts working in combination with 4th gen fighters against 5th gen stealth this will give some clarifiction

 

[ersakthivel]

Is there any difference in dimensions between other tejas PVs and LSP-7 in dimensions?
There is a big bump near the verticlal tail fin.

The below is the picture of another tejas.

 

[ersakthivel]

 

[ersakthivel]

 

[ersakthivel]

 

[ersakthivel]

 

[ersakthivel]

Re: ADA Tejas (LCA) - III

 

[ersakthivel]

 

[ersakthivel]

 

[ersakthivel]

 

[ersakthivel]