Tejas Mk.1 & Mk.1A News & Discussions: 09 February 2018

Vidur · Post by **Vidur** » 22 Mar 2018 13:21

Sir,

I absolutely did not say that on the Arjun thread. You said that 'Engineer in me rebels when I am told that I need to have a 4 man crew, better suspension, better armour but no weight'. I challenged that and said that between T90 and Arjun 1 there was a significant weight increase allowed and rightly so. So your point was false and I said so.

I also have substantial experience in these matters having not followed them but done them first hand and still do so I also know what I am talking about. There is no aparthied of any kind.

Lastly its sad that you refuse to read perhaps the best journalistic work on Indian security written by one of the most respected defence journalists. He has the kind of access that gives him the clearest picture of national security. And he is no 'Bhakt' as I believe you refer to. To those that have read his book....is it vyakti pooja ?

Indranil · Post by **Indranil** » 22 Mar 2018 13:48

I modified my post before seeing your reply. It is okay. I agree with you that gare murde ukhadne ke koi faide nahi hai. There is good synergy between IAF and the Tejas team now. And we can leave it at that happy note.

I don't intend to modify anybody's world views. I will wait for you to show me a world class tank with 4 man-crew which significantly lighter. Until that time, it is difficult for me to accept that my viewpoint there is false. Here are some examples for your reference: Challenger 2 (62.5-75 tons), Leclerc (58 -70 tons), Leopard 2 (62.3 -72 tons), Merkava (65 tons), M1A2 (72 tons).

Pratyush · Post by **Pratyush** » 22 Mar 2018 14:05

Guys why Arjun is being discussed in Tejas thread.

Akshay Kapoor · Post by **Akshay Kapoor** » 22 Mar 2018 14:30

Indranil wrote:I modified my post before seeing your reply. It is okay. I agree with you that gare murde ukhadne ke koi faide nahi hai. There is good synergy between IAF and the Tejas team now. And we can leave it at that happy note.

I don't intend to modify anybody's world views. I will wait for you to show me a world class tank with 4 man-crew which significantly lighter. Until that time, it is difficult for me to accept that my viewpoint there is false. Here are some examples for your reference: Challenger 2 (62.5-75 tons), Leclerc (58 -70 tons), Leopard 2 (62.3 -72 tons), Merkava (65 tons), M1A2 (72 tons).

Indranil, Vidurji has clearly said that no one is asking for Arjun Mk 1 to be lighter. The fact that it is 60 tons is fine...in his words 'rightly so'. Why take so much tension. And for gods sake how is Nitin Gokhales book or Vidur's comment that we have a good PM ,Vyakti Pooja.

Kersi · Post by **Kersi** » 22 Mar 2018 14:55

Singha wrote:if the GSH23-2 is too powerful and vibratory, i wounder if the 30mm defa cannon on jaguar could be used?

the DEFA is single barrel
Rate of fire 1,300 rpm
Muzzle velocity 815 m/s (2,670 ft/s)

GSH23-2
Rate of fire 3,400-3,600 rounds/min (alleged)
Muzzle velocity 715 m/s (2,350 ft/s)

the DEFA is also heavier hence will not vibrate as much 85kg vs 50kg
it is already used in our Jaguar and Mirage2000, so we understand it and service it.

I thought Jaguars had Aden 30 mm cannon

shiv · Post by **shiv** » 22 Mar 2018 18:21

Kersi ADEN has slower rate of fire and each round is heavier. As it is I think GSh was restricted to maybe 120 rounds (not sure)

Singha · Post by **Singha** » 22 Mar 2018 18:43

wiki claims DEFA(france) and ADEN(uk) are of the same species ...GIAT also introduced their version of the design as the DEFA cannon. The two weapons are very similar and can use the same ammunition.

we have used it in multiple a/c including the hawker hunter which had 4 of these sweet things.

unlike the good old days when 100s of rounds per gun were carried and used , modern fighters seem to have a token number of rounds and have auto limits on how long the bursts can be vs the old P51/sturmovik/mosquito types which could fire off hellaciously long bursts of fire from multiple guns in parallel.

the beloved de havilland "mossie"

srin · Post by **srin** » 22 Mar 2018 19:20

Singha-ji, how long before you start salivating over the Gsh-630 ?

ramana · Post by **ramana** » 22 Mar 2018 19:31

shiv wrote:Kersi ADEN has slower rate of fire and each round is heavier. As it is I think GSh was restricted to maybe 120 rounds (not sure)

Another way of saying is the GSh 23 with twin barrels in one location has higher rate of fire and occupies less space on Tejas.

For comparison one can compare the kinetic energy of a 30mm NATO round and 23 mm GSh round. Add rate of fire and an increment for explosive energy and compare the gun stations.
Will do it this weekend.
That way we bring facts to table.

Gagan · Post by **Gagan** » 22 Mar 2018 20:47

With regards to the 3000 + flights including operational flying now, and no crash.

This has to be attributed to the servicing team, the engineers etc at ADA and HAL. These guys must have put in ungodly man hours for each hour of flying.
They proved that the bird could fly, painstakingly certified each parameter over and over again.
The toil and sweat they put in is surely unparalleled. They truly are Bharat Ratnas !!!

sudeepj · Post by **sudeepj** » 22 Mar 2018 21:35

Vidur wrote:I also do not understand the angst when the LCA project is finally taking off and strong commitment has been made by all concerned. Why this negativity ? As far as I know the relationships between the IAF and ADA as evidenced by the NTFC are excellent. I have never seen such a high level of mutual respect and joint vision in the govt. There are concerns about the production agency though. But I really do not understand why this angst at a time when we should be looking forward with hope.

Not negativity, but an analysis of what went wrong in the past and how. Going back to the comment that started this all, with all the humility that I can possibly gather, IMHO, the fact that not a single LCA crashed means that the test program was very heavily de-risked. The heavy focus on derisking the test program was because the program managers felt that a single mishap was all it would take to can the program altogether! In other words, they felt that there was insufficient political, bureaucratic and intellectual (from the user community, from internal think tanks) commitment to the idea of a domestically produced fighter. We can exchange backslaps today at the success of the Tejas, but this (insufficient commitment) is a point of view that repeatedly comes up.

The forced de-risking comes at a price of slow progress and extracts a price in strategic as well as human terms. If we were flying a hundred of these fighters today, our strategic heft would be quite different from what it is. In human terms, we would also have seen fewer crashes of the Migs etc. The recent picture of the Mig21 that Flt. Lt. Avani Chaturvedi was getting in was an embarrassment.

Finally, when the focus is on de-risking the program, it detracts from de-risking other very important aspects - derisking technology obsolescence, timelines, production/numbers, innovation etc.

Once again, just my personal opinions, no hard feelings towards anyone. Perhaps this is also a lesson we needed to learn the hard way.

shiv · Post by **shiv** » 22 Mar 2018 22:09

Sudeepj makes a very important point. One crash and the program is all but dead. This is typical because as a nation we crinkle up our noses at anything Indian - we the educated are attuned to thinking about our compatriots the way a Brit colonizer or other superior but patronizing being might look at Indians. The HS 748 flying idli crashed - and the program died. Saras - nearly dead. IJT probably dead. I have often pointed out that a comparison with ISRO is misplaced because a rocket launch failure leads to no human fatality/injury. I do believe that the Tejas team have bent over backwards to ensure that there were no accidents.

It was not always this way. The HF 24 started with a crash - a bad omen but gora aadmi was leading and it went on till gun trials and engine did it in. The Kiran had many accidents - I lost a good friend - a test pilot in a late 1970s Kiran accident. Compared with that the Gnat was a flying disaster.

Of course in the west programs simply pick up and take off again after an accident. That was not something the developers of the Tejas were willing to risk. Kudos to them

Rishi_Tri · Post by **Rishi_Tri** » 22 Mar 2018 22:24

Gagan wrote:With regards to the 3000 + flights including operational flying now, and no crash.

This has to be attributed to the servicing team, the engineers etc at ADA and HAL. These guys must have put in ungodly man hours for each hour of flying.
They proved that the bird could fly, painstakingly certified each parameter over and over again.
The toil and sweat they put in is surely unparalleled. They truly are Bharat Ratnas !!!

++++

JayS · Post by **JayS** » 22 Mar 2018 22:39

Gagan wrote:With regards to the 3000 + flights including operational flying now, and no crash.

This has to be attributed to the servicing team, the engineers etc at ADA and HAL. These guys must have put in ungodly man hours for each hour of flying.
They proved that the bird could fly, painstakingly certified each parameter over and over again.
The toil and sweat they put in is surely unparalleled. They truly are Bharat Ratnas !!!

Err..saar..4000+

Vidur · Post by **Vidur** » 22 Mar 2018 22:51

shiv wrote:Sudeepj makes a very important point. One crash and the program is all but dead. This is typical because as a nation we crinkle up our noses at anything Indian - we the educated are attuned to thinking about our compatriots the way a Brit colonizer or other superior but patronizing being might look at Indians. The HS 748 flying idli crashed - and the program died. Saras - nearly dead. IJT probably dead. I have often pointed out that a comparison with ISRO is misplaced because a rocket launch failure leads to no human fatality/injury. I do believe that the Tejas team have bent over backwards to ensure that there were no accidents.

It was not always this way. The HF 24 started with a crash - a bad omen but gora aadmi was leading and it went on till gun trials and engine did it in. The Kiran had many accidents - I lost a good friend - a test pilot in a late 1970s Kiran accident. Compared with that the Gnat was a flying disaster.

Of course in the west programs simply pick up and take off again after an accident. That was not something the developers of the Tejas were willing to risk. Kudos to them

And congratulations also to the test pilots and NTFC directors. I met one of them when he was an Air Marshal and he told me how he used to have 'what if meetings'...they would imagine every eventuality and find a counter for that and then test it on a test bed and then fly. He was very complimentary about his colleagues at ADA.

Indranil · Post by **Indranil** » 23 Mar 2018 00:42

I think we should learn to keep our stories straight.

1. Is the Gripen/F-16 adequate for India or not? The answers can't keep changing on a yearly basis.
2. The meddling of the govt., babus in technical decisions is good or not? The answers can't change based on the govt.
3. The Arjun is too heavy or not? If not, why no orders yet!
4. Gripen E to be certified in 2025 is considered in 2007? Mk2/AMCA drawn up and PSED completed years back has to wait for salary money in 2018. Apartheid or not?

We should not have to lean on the faith on govt., reporter or anybody for that matter to justify decisions. They should be able to stand on their own merit.

ABSOLUTELY NO MORE ON THIS FROM ME.

Nishn · Post by **Nishn** » 23 Mar 2018 04:30

--- del ----

ArjunPandit · Post by **ArjunPandit** » 23 Mar 2018 05:12

--- del ----

Rakesh · Post by **Rakesh** » 23 Mar 2018 05:19

Indranil wrote:3. The Arjun is too heavy or not? If not, why no orders yet!

My comment on this point is in the Arjun dhaaga.

viewtopic.php?f=3&t=7051&p=2260629#p2260629

Rakesh · Post by **Rakesh** » 23 Mar 2018 08:19

Guys, please no more discussions on anything else other than Tejas Mk1 and Mk1A. Thank You.

Singha · Post by **Singha** » 23 Mar 2018 08:58

guns imo are great VFM for shooting down UAV/UCAV rather than a expensive AAM/SAM esp at tactical drone level.
some of the new long loiter COIN oriented a/c might do it, or else helicopter gunships.

for ground attack, a new trend seems to be large caliber laser guided rockets fired from pods. dont know cost/round. perhaps range is 2km same as unguided rockets. laser guidance however means you cannot fire a nice salvo of rockets in a dive and then turn away at low level. perhaps only helicopters do laser guided rockets than fixed wing fast movers.

JayS · Post by **JayS** » 23 Mar 2018 12:24

Vidur wrote:I also do not understand the angst when the LCA project is finally taking off and strong commitment has been made by all concerned. Why this negativity ? As far as I know the relationships between the IAF and ADA as evidenced by the NTFC are excellent. I have never seen such a high level of mutual respect and joint vision in the govt. There are concerns about the production agency though. But I really do not understand why this angst at a time when we should be looking forward with hope.

Sir, a part of problem is the lack of credible information from GOI side on status of projects like LCA. Even if the projects are on track by and large and things proceed as expected in the background (only a few phases of procurement are visible to public), there is no real credible info on the status. OTOH there is a lot of negative information being spread around in MSM by 'paid tattoo' and vested interests, mostly in the name of "unnamed GOI or IAF sources". Its not easy to keep faith in GOI in such situations for even the most optimistic jingo. And some seemingly credible people ranting based on prejudices rather than facts, do more damage to the cause. Today the situation is, it still takes a bit of forced optimism to think that large number of orders for LCA, or LCH or Dhanush or ATAGS are a sure thing. 7 decades of negativity will not be washed away just like that.

They say, in India, those who know never talk, and those who talk never know much about the matters. But its the later who control discourse. Even the seasoned BRFites get rattled at times. One can only imagine what aam abdul must be thinking.

Bala Vignesh · Post by **Bala Vignesh** » 23 Mar 2018 15:32

How the USAF chief ended up in the LCA.
Must say the USAF guys are taking this Bonhomie to a new level by asking the serving chief be taken on a Joy ride in our premier frontline fighter on an official visit. What's even more good is how the MoD and MoEA turned it around and got him to ride the Tejas!! Brilliant move, I say!!

suryag · Post by **suryag** » 23 Mar 2018 17:35

Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads

ashishvikas · Post by **ashishvikas** » 23 Mar 2018 23:09

suryag wrote:Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads

Sir, this is for MK1 only.

Kartik · Post by **Kartik** » 23 Mar 2018 23:22

suryag wrote:Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads

Add the Mach 1.6 max speed.

fanne · Post by **fanne** » 24 Mar 2018 02:54

24 deg AOA is sustained or instant?

Indranil · Post by **Indranil** » 24 Mar 2018 04:23

That question is not complete. You have to specify the G-load. At 1 G it can do a sustained low pass

. Can't sustain it at 8G!

But I understand what you are trying to ask. How hard can Tejas turn? AoA is related to turn rate, but is not a measure of turn rate. For example, plane A is likely to turn faster than itself at a higher AoA. However, Plane A may turn slower than plane B even if it is flying at a higher AoA than the latter.

At Bahrain, we saw Tejas completing 90 degree turns at 3.x secs, full turns in 20-some seconds and turn radius of 350 meters. Those are all very good numbers.

shiv · Post by **shiv** » 24 Mar 2018 07:57

fanne wrote:24 deg AOA is sustained or instant?

This is the first time in my life I have heard anyone asking about sustained versus instant AoA. I have always heard the term applied to roll rates which in turn translates to turn rate because planes must roll/bank and raise AoA to turn at high or low G

As I understand it when one increases AoA - be it 12 degrees of 24 or 36 one of three things can happen

1. The plane does a loop
2. The plane manages to fly level at that AoA
3. It stalls and falls.

shiv · Post by **shiv** » 24 Mar 2018 08:03

suryag wrote:Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads

In the numerous anecdotes one reads about older aircraft - one finds that they too were "certified" to x G and it was up to the pilots to make sure that they (manually/voluntarily) did not exceed that. From this fact emerge the exciting tales of pilots who exceeded the G limits either to escape a tricky situation or something else. I recently read a story (may have been HF 24???) in which on a challenge - a pilot pulled such high G that one of the pylons tore off and the G meter was stuck at max. Of course we will never hear the stories of people who did excess high G and either lost control (lost consciousness or a wing

In a plane like the Tejas "certified for 8 G" means that the FBW software will not allow the plane to exceed 8G until some future date when they may increase that

fanne · Post by **fanne** » 24 Mar 2018 08:29

My bad, wrong question, it should have been turn rate per sec (sustained vs instant), which is in degree wise almost in same range.

Singha · Post by **Singha** » 24 Mar 2018 09:06

Is there a term corner velocity to indicate the speed at maximum sustained horizontal turn rate? Higher the better

This is where non delta large motor planes like f16 are said to excel though canards may help some

shiv · Post by **shiv** » 24 Mar 2018 09:47

Singha wrote:Is there a term corner velocity to indicate the speed at maximum sustained horizontal turn rate? Higher the better

This is where non delta large motor planes like f16 are said to excel though canards may help some

I have not heard the term applied to aircraft.

As far as my knowledge goes it is not the maximum speed during a turn that is critical but the bank angle. No matter what the speed of the aircrfat - a bank angle of 60 degrees =2G. 8 G is a bank angle of approximately 83 deg

At any given bank angle - if the speed is increased, the plane will gain height, or if the bank angle is increased the plane will do a higher G turn.

Some information at this link
http://www.cfinotebook.net/notebook/aer ... erformance

Indranil · Post by **Indranil** » 24 Mar 2018 10:01

fanne wrote:My bad, wrong question, it should have been turn rate per sec (sustained vs instant), which is in degree wise almost in same range.

Could not follow the bolded part. STR and ITR will not be revealed in public. All I have heard is that ITR is "phenomenal" and the STR "good enough". Mk2 will improve on STR further. But it has got nothing to do with AoA.

ashishvikas · Post by **ashishvikas** » 24 Mar 2018 10:06

Kartik wrote:
suryag wrote:Tejas FB confirmed the envelope for MK1A - 15Km ceiling, 24deg AoA and certified for 8G loads
Add the Mach 1.6 max speed.

Sir, this is current status, so is it for IOC2 configuration ?

and will FOC have something more ?

Indranil · Post by **Indranil** » 24 Mar 2018 10:16

Singha wrote:Is there a term corner velocity to indicate the speed at maximum sustained horizontal turn rate? Higher the better

This is where non delta large motor planes like f16 are said to excel though canards may help some

Yes, corner speed is the minimum speed at which maximum turn rate can be achieved. But lower is better.

By the way, F-16 has a cropped delta wing. Modern deltas have overcome a lot of the STR detriments. Canards do help by lowering wing loading of the main wing(more efficient lift generation).

If Mk2 stays true to its root of a light fighter and doesn't try to be a wanna-be medium weight like Gripen E, it will have very good STR. The main aspects of STR is L/D and TWR. If Mk2's empty weight stays below 7 tons, then it will have very good TWR. You all will see major changes done to increase L/D.Canards and reshaping of the area behind of the canopy, actuator fairings, pylons and inlet is already public. Please wait for other changes to become public. It will be a very refined plane.

Kartik · Post by **Kartik** » 24 Mar 2018 11:13

Woohoo!

SP-9 took off on its first flight today, flown by Air Cmde Muthanna (retd).

LCA Tejas SP-9 successfully completes first flight
24th March 2018

LCA Tejas SP-9 (LA-5009) successfully flew for the first time today taking off at 1033 hrs from HAL Airport in Bengaluru and landing back at 1054 hrs. SP-9 flew for 21 mins with Air. Cmde KA Muthanna (Retd) in the cockpit. This is the Ninth Series Production Aircraft and will be handed over to the No.45 Squadron of the Indian Air Force also called the 'Flying Daggers' after a few production sorties
Photo for representational purposes only.
#LCATejas #SeriesProduction #FlyingDaggers45 #IAF #HAL #ADA

Indranil · Post by **Indranil** » 24 Mar 2018 12:21

So 4 aircrafts made maiden flights since Dec 12, 2017. Should we say that production rate has reached 10-11 per year? Obviously not. But where are those guys who used the opportune window of some teething troubles (with SP5) to say HAL could only only produce 2/3 aircraft per year.

Indranil · Post by **Indranil** » 24 Mar 2018 12:22

That final stick of misinformation that Tejas can't produced quickly enough in desh has to be broken.

Pratyush · Post by **Pratyush** » 24 Mar 2018 13:05

Indranil wrote:That final stick of misinformation that Tejas can't produced quickly enough in desh has to be broken.

This is a great news. The last major issue that remains is a sanctions proof and reliable engine. Only way it can happen is by having a domestic engine.

404 / 414 are interim solutions. We need Kaveri to be on full stream.