ADA Tejas (LCA) News and Discussions

[Enquirer]

Maybe, I can be wrong. It would help if someone (not ersa) would shed some light on this stuff. I am a bit confused about the speed during free fall.

Firstly you're smart is asking ersakthivel not to intervene

As I've always said, that moron doesn't understand even high school level physics!!!

Take for example the dive from 4000 m altitude! Even if there was NO AIR RESISTANCE at all, a vertical dive (a free fall) from 4000 meters will NEVER attain supersonic speed. Simple math & physics!!!
Add in air resistance, the drag would reduce the free fall velocity drastically (even in a nose dive)!


So, it's just a bag full of bullshit and lies that ersakthivel keeps peddling on this forum. He concocted a lie that the flight during the test was unpowered!

Further, irrespective of anything he's been croaking recently he hasn't shown any evidence that sound barrier was breached by Tejas at sea level in a level-flight (you were right to kick him in the nuts with that question!)

Sorry for my poor language; this false-science peddling fool has annoyed me to no end!

 

[Sancho]

so if all these are done gradually, Mk1+ may also be a very decent fighter with some 2000 km range and 4 ton weight. All depends on how you pursue improvements.

Range is not the issue, for a fighter that is designed to defend and patrol specific areas within India and close to it's bases.
That's just one more misconception about Tejas, because people want to make more out of it, than it is intended to. The problem is flight performance and endurance!

The solution for flight performance is the higher thrust engine and aerodynamic fixes and while the MK1 airframe can get some aerodynamic improvements, it's already established that only the MK2 will be able to bring LCA to the required flight performance =>

https://defenceforumindia.com/forum...-news-and-discussions.1/page-858#post-1447225

The solution to increase the endurance was, to add IFR capability and mabye if the planned new supersonic fuel tanks will offer some increase in fuel capacity as well.

MK1 FOC can be a "decent" 4th gen multi role fighter for sure, since it will give IAF modern multi role capabilities. But it falls short to what it was suppose to offer, to be a good fighter at IAFs low end. Now the hope remains on MK2, to finally get Tejas to be a good low end fighter, but that needs to be seen and the longer it takes, the more air combat changes, to reduce it's worth.

 

[Flame Thrower]

This is 3100 meter in 5 second is a speed of 1860 KM per hour. It is great. What is the highest speed Tejas done till date? In my knowledge it is 1699 KM for air force Tejas in high altitude flight without any dive.

The speed is 2232kmph not 1860.

More over we have taken the average of 5 sec descent. So speed should be way higher than the 2232kmph on the last second of descent.

1200kmph is the roughly the speed of sound.

@ersakthivel I think the descent was more than 5 sec as there is no way Tejas could have covered the 3100mts descent in such a short time. Maybe a wrong time calculation.

 

[Flame Thrower]

Firstly you're smart is asking ersakthivel not to intervene

As I've always said, that moron doesn't understand even high school level physics!!!

Take for example the dive from 4000 m altitude! Even if there was NO AIR RESISTANCE at all, a vertical dive (a free fall) from 4000 meters will NEVER attain supersonic speed. Simple math & physics!!!
Add in air resistance, the drag would reduce the free fall velocity drastically (even in a nose dive)!


So, it's just a bag full of bullshit and lies that ersakthivel keeps peddling on this forum. He concocted a lie that the flight during the test was unpowered!

Further, irrespective of anything he's been croaking recently he hasn't shown any evidence that sound barrier was breached by Tejas at sea level in a level-flight (you were right to kick him in the nuts with that question!)

Sorry for my poor language; this false-science peddling fool has annoyed me to no end!

I think you've misinterpreted, he said sound barrier was broken after the pilot pulled the stick, i.e in powered flight.

 

[Enquirer]

I think you've misinterpreted, he said sound barrier was broken after the pilot pulled the stick, i.e in powered flight.

There're at least a dozen posts by that idiot claiming that the flight was without power!
Although no where in the articles is it mentioned that the engine was cut off - only that the pilot allowed for a dive!
Also, it should be fairly obvious that a aircraft cannot free fall 3700 meters in just 5 seconds (obviously it was a powered dive).

All in all, it's quite stupid for grown men to be arguing about something that a high school kid would mock at!!!
This moron, ersakthivel has made a mockery of this thread with his dumb ass foolery!

 

[shiphone]

relatively speaking, dive or level fly is not that important

I would like to revise this early statement which is not very suitable here....and we still think this '1350km/h' is a level flying speed...

we might be able to describe this flying test like is:

1. LCA takes off , climes to some altitude(eg. 4km ) and reach some speed at that level.--- the potential energy+kinetic energy status established
2. then it dives with the engine after burner on. it is a great acceleration process, engine power keeps increasing the airplane speed, and the potential energy also helps the acceleration process.
3. then the plane levels off at the low level (a big g-load will happen) with a high speed
4. although the much higher drag at low level and flutter getting Critical, the level flying plane will still accelerate coz the engine have the margin and the plane gets lighter with fast fuel consuming.
5. then the plane will get to the designed/ Theoretical Calculated MAX flying speed at this level. the plane will sustain this speed for some time and the flutter status is controllable/safe.
6. this speed then is the valid value/result of this 'designed' flying test.

why dive?

1. obviously , that flying profile is quite effective/efficient , after all getting the absolute flying speed is the goal/purpose.
2. the plane might be able to get this speed with the max engine thrust in an all time low-level flying. but the limitation is the inner fuel tank capacity. the jet might not get that speed due to the relatively slow and Looooong acceleration and the fuel would drop down to the 'bingo' status before the higher speed achieved...
3. again, this 'speed value' indicates that LCA is structure strong and aerodynamic safe enough for such dangerous low level high speed in dense air flow...

------------
BTW, J-10 did the same flying test with similar flying profile design. the test pilots explained the details well in the interview. and the test team was chasing Cold air mass within the north China in some winter for the better conditions in those times.

 

[Enquirer]

I would like to revise this early statement which is not very suitable here....and we still think this '1350km/h' is a level flying speed...

we might be able to describe this flying test like is:

1. LCA takes off , climes to some altitude(eg. 4km ) and reach some speed at that level.--- the potential energy+kinetic energy status established
2. then it dives with the engine after burner on. it is a great acceleration process, engine power keeps increasing the airplane speed, and the potential energy also helps the acceleration process.
3. then the plane levels off at the low level (a big g-load will happen) with a high speed
4. although the much higher drag at low level and flutter getting Critical, the level flying plane will still accelerate coz the engine have the margin and the plane gets lighter with fast fuel consuming.
5. then the plane will get to the designed/ Theoretical Calculated MAX flying speed at this level. the plane will sustain this speed for some time and the flutter status is controllable/safe.
6. this speed then is the valid value/result of this 'designed' flying test.

why dive?

1. obviously , that flying profile is quite effective/efficient , after all getting the absolute flying speed is the goal/purpose.
2. the plane might be able to get this speed with the max engine thrust in an all time low-level flying. but the limitation is the inner fuel tank capacity. the jet might not get that speed due to the relatively slow and Looooong acceleration and the fuel would drop down to the 'bingo' status before the higher speed achieved...
3. again, this 'speed value' indicates that LCA is structure strong and aerodynamic safe enough for such dangerous low level high speed in dense air flow...

------------
BTW, J-10 did the same flying test with similar flying profile design. the test pilots explained the details well in the interview. and the test team was chasing Cold air mass within the north China in some winter for the better conditions in those times.

The steps you enumerated are probably correct. The inference on structural strength is also accurate.

However, the scope of the recent spat was not about the structural strength of Tejas but it's aerodynamic/drag profile. Diving to attain a 1.1 mach at sea level for test is perfectly valid. But that is not considered as flying Mach+ at sea level (not level flight, as the thrust cannot sustain that velocity).

Moreover it's disingenuous of some know-nothings to claim that Mach 1.1 attained via a powered dive is same as Su-30MKI sustaining a Mach 1.1 at sea level.

It's an insult to the intelligence of the scientifically inclined folks to be asked to stomach faux-science nonsense just because the guy peddling it gets a hard on looking at Tejas or flunked high school physics!

 

[ersakthivel]

This moron ersakthivel once again has had an episode where he vomits and diarrheas at the same time. I would hate to wade through his shit.

But I do see the smelliest top crap (immediately above this post) and would like to spray some disinfectant on it!!

As i’ve mentioned earlier (i’ve lost count of the number of times), improper compliance to Area rule will not disallow supersonic flight; it’ll only require more thrust (not efficient). Reason why MK1 Max speed is also lower than desired.

If the ADA Chief himself has said that MK1 airframe has issue with Area rule compliance(that will be rectified in Mk2), why is this joker getting so worked up???

Can he now close his top and bottom openings?

"As i’ve mentioned earlier (i’ve lost count of the number of times), improper compliance to Area rule will not disallow supersonic flight; it’ll only require more thrust (not efficient). Reason why MK1 Max speed is also lower than desired.

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constant
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constant
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

Force of gravity pulls tejas in downward direction.

But the pilot ACTS AGAINST THIS FORCE , WHEN HE TRIES TO PULL THE FIGHTER TO LEVEL FLIGHT.

He is not acting with gravitational force.

So in essence , this is not a powered drive towards the earth is my opinion.
TThats why ADA mentions ,
Flight envelope is expanded to supersonic speeds at sea level.

That's my understanding of the ec


T

 

[ersakthivel]

This moron ersakthivel once again has had an episode where he vomits and diarrheas at the same time. I would hate to wade through his shit.

But I do see the smelliest top crap (immediately above this post) and would like to spray some disinfectant on it!!

As i’ve mentioned earlier (i’ve lost count of the number of times), improper compliance to Area rule will not disallow supersonic flight; it’ll only require more thrust (not efficient). Reason why MK1 Max speed is also lower than desired.

If the ADA Chief himself has said that MK1 airframe has issue with Area rule compliance(that will be rectified in Mk2), why is this joker getting so worked up???

Can he now close his top and bottom openings?

"As i’ve mentioned earlier (i’ve lost count of the number of times), improper compliance to Area rule will not disallow supersonic flight; it’ll only require more thrust (not efficient). Reason why MK1 Max speed is also lower than desired.

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constant
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constant
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

Force of gravity pulls tejas in downward direction.

But the pilot ACTS AGAINST THIS FORCE , WHEN HE TRIES TO PULL THE FIGHTER TO LEVEL FLIGHT.

He is not acting with gravitational force.

So in essence , this is not a powered drive towards the earth is my opinion.
TThats why ADA mentions ,
Flight envelope is expanded to supersonic speeds at sea level.

That's my understanding of the ec


T

 

[Narasimh]

I have the same doubt.. But can it be called truly supersonic if it reaches supersonic only in dive and not in level flight. I thought the fighters ought to be tested for supersonic speeds in level flight only.
If the diving case is true then tejas would not be just able to put on reheat and get out of any engagement quickly. And is IAF OK with that?

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constant
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

 

[Enquirer]

I have the same doubt.. But can it be called truly supersonic if it reaches supersonic only in dive and not in level flight. I thought the fighters ought to be tested for supersonic speeds in level flight only.
If the diving case is true then tejas would not be just able to put on reheat and get out of any engagement quickly. And is IAF OK with that?

The speed capability varies with altitude, as drag decreases with rarefied air.
I do believe Tejas CAN fly supersonic in level flight AT HIGHER ALTITUDES.
There's however no evidence that Tejas can go supersonic in level-flight at sea level.
To attain higher speeds at lower altitudes 2 things need to be done: Decrease drag profile (conform more to Whitcomb Area rule) & increase thrust - both of which are the endeavor in Mk2.

 

[Narasimh]

The speed capability varies with altitude, as drag decreases with rarefied air.
I do believe Tejas CAN fly supersonic in level flight AT HIGHER ALTITUDES.
There's however no evidence that Tejas can go supersonic in level-flight at sea level.
To attain higher speeds at lower altitudes 2 things need to be done: Decrease drag profile (conform more to Whitcomb Area rule) & increase thrust - both of which are the endeavor in Mk2.

So does it make more sense to deploy Tejas(mk1) in mountain air bases like Leh or Hasimara rather than southern air bases? Not sure how it impacts the combat load at those places and also I am thinking more from the VWR combat scenarios rather than BVR.

 

[Jackd]

In my opinion (some of you might also think the same) Tejas mk1 should be treated as a stepping stone and sort of a plane which you use to test plethora of tech that is being developed. The endeavour of the parties involved should be to learn from this experience and make Tejas Mk2 a truly world class fighter, which satisfies the IAF, IN as well as has potential for exports.
Criticism that is being hurled at Tejas mk1 is a bit unfair and maybe to some of us justified but Tejas mk2 should (will) be a plane which will destroy all critics of the Tejas program.

 

[Enquirer]

So does it make more sense to deploy Tejas(mk1) in mountain air bases like Leh or Hasimara rather than southern air bases? Not sure how it impacts the combat load at those places and also I am thinking more from the VWR combat scenarios rather than BVR.

Not necessarily. Even though the take off altitude is different in Leh & the South, the operational altitude could be similar.

Even in the north, close air support ops in the Punjab plains will require low altitude flights (even though not at sea level); while ant-ship roles in the south may not require sea level flights.

 

[ersakthivel]

Maybe, I can be wrong. It would help if someone (not ersa) would shed some light on this stuff. I am a bit confused about the speed during free fall.

That needs clarification from official agencies like HAL, ADA, DRDO.

when the plane reached 900 meters above sea level,

To break out of dive at supersonic speeds, or subsonic speed

Is the issue.
If it was supersonic throughout the dive

Or it went to subsonic speeds , when it tried to break out & then went supersonic

Needs clarification

 

[ersakthivel]

"The aircraft went past its ultimate speed of 1350 kmph on December 7 over the skies in Goa after take off from the naval air station INS Hansa," Commander Rohit Varma, project director (flight test), National flight test centre, told reporters here.

"This is the fastest speed ever achieved by an Indian- made fighter aircraft," he said.

The aircraft also passed flight flutter test diving from an altitude of four kilometers to almost sea level at 900 feet. Quoted from Indian express article.

Nowhere does it say that Tejas achieved this speed while in level flight (altitude is maintained) and until you can provide some conclusive evidence, I am inclined to believe that Tejas achieved this speed during its dive phase.

Also, this was mentioned on the FAA website: https://www.faa.gov/pilots/safety/pilotsafetybrochures/media/Acceleration.pdf
"The force of gravity on earth causes a constantl
acceleration of 32 feet-per-second squared. An object
in freefall will accelerate at an ever-increasing speed
toward earth."

Is it akin to a formula one race car entering a corner at 200 + kmph ,

Breaking

Transferring it's momentum in a different direction,
Then getting the same 200+ hour speed back

or?

Without breaking it maintained the same 200+ km speed through out the curve.

Remember it's a steep dive to 900 mts above sea level altitude,

With close to km per sec speed (4 kms in 5 seconds)

Then for the flight to get level,

The speed should be reduced by the effort to pull up is my opinion,

But whether it was reduced enough for plane to go subsonic & then supersonic again is the issue

 

[ersakthivel]

Firstly you're smart is asking ersakthivel not to intervene

As I've always said, that moron doesn't understand even high school level physics!!!

Take for example the dive from 4000 m altitude! Even if there was NO AIR RESISTANCE at all, a vertical dive (a free fall) from 4000 meters will NEVER attain supersonic speed. Simple math & physics!!!
Add in air resistance, the drag would reduce the free fall velocity drastically (even in a nose dive)!


So, it's just a bag full of bullshit and lies that ersakthivel keeps peddling on this forum. He concocted a lie that the flight during the test was unpowered!

Further, irrespective of anything he's been croaking recently he hasn't shown any evidence that sound barrier was breached by Tejas at sea level in a level-flight (you were right to kick him in the nuts with that question!)

Sorry for my poor language; this false-science peddling fool has annoyed me to no end!

Yo eggspurt,

What happens when pilot takes off his hands from controls?

Stuff like this is too much for you,
Plus it is your egg head which assumes the plane dived like a stone with nose down & tail up mode, with full after burner.

 

[Enquirer]

Yo eggspurt,

What happens when pilot takes off his hands from controls?

You're pathetic!!
You constantly keep deflecting the topic to escape shame!

I stopped reacting to your vomit/diarrhea! One of your 'chelas' seemed to echo your words, and I had to respond.

How many public floggings do you get from me everyday?? And you shamelessly keep pretending that your ass is not whipped and keep coming back for more!!!

 

[ersakthivel]

[QUOT hiE="Enquirer, post: 1448198, member: 26158"]You're pathetic!!
You constantly keep deflecting the topic to escape shame!

I stopped reacting to your vomit/diarrhea! One of your 'chelas' seemed to echo your words, and I had to respond.

How many public floggings do you get from me everyday?? And you shamelessly keep pretending that your ass is not whipped and keep coming back for more!!![/QUOTE]


"In such a short duration, it had plummeted from four kilometres above sea level to just 900 metresbefore the pilot hit to the throttle again to take to the skies."..


What does it mean???
PILOT HIT THE THROTTLE AGAIN.

just rinse you fingers & mouth in toilet cleaning liquid,

Before using them here again.

Because,
Is it akin to a formula one race car entering a corner at 200 + kmph ,

Breaking

Transferring it's momentum in a different direction,
Then getting the same 200+ hour speed back

or?

Without breaking it maintained the same 200+ km speed through out the curve.

Remember it's a steep dive to 900 mts above sea level altitude,

With close to km per sec speed (4 kms in 5 seconds)

Then for the flight to get level,

The speed should be reduced by the effort to pull up is my opinion,

But whether it was reduced enough for plane to go subsonic & then supersonic again is the issue

 

[HariPrasad-1]

Take for example the dive from 4000 m altitude! Even if there was NO AIR RESISTANCE at all, a vertical dive (a free fall) from 4000 meters will NEVER attain supersonic speed. Simple math & physics!!!
Add in air resistance, the drag would reduce the free fall velocity drastically (even in a nose dive)!


So, it's just a bag full of bullshit and lies that ersakthivel keeps peddling on this forum. He concocted a lie that the flight during the test was unpowered!

This sound much logical. You can not travel 3100m in simple free fall in 5 second as g value is 9.8m/s. Plane struck a 1860 KM speed on an average during that 5 second. This speed is not possible in free fall.