LCA News and Discussions

Telang · Post by **Telang** » 17 Aug 2010 01:45

Gurus, masters and countrymen, pleeeaaaase, time to come out of hibernation (or hiding) and post some thing sensible. Elevate the discussion.

Drishyaman · Post by **Drishyaman** » 17 Aug 2010 21:15

One question going through my mind, hopefully somebody can clarify.... Its regarding the IAF Tejas Trainer and IN Tejas Trainer...
What I have read is both IAF Tejas Trainer and IN Tejas Trainer has got multiple points of similarity...
My doubt is.... if IAF Tejas Trainer's nose is as much slopped down as much as the IN Tejas Trainer ?

Telang · Post by **Telang** » 18 Aug 2010 23:47

B_Ambuj wrote:One question going through my mind, hopefully somebody can clarify.... Its regarding the IAF Tejas Trainer and IN Tejas Trainer...
What I have read is both IAF Tejas Trainer and IN Tejas Trainer has got multiple points of similarity...
My doubt is.... if IAF Tejas Trainer's nose is as much slopped down as much as the IN Tejas Trainer ?

Please remember, I am just 'sombody' and not a Guru. I could be wrong.

There are very few trainer aircraft now (may be none), especially among jet fighters which have side-by-side 'abreast seating' (IIRC, Hunters and Vampires did have seats abreast), mostly the arrangement is in tandem.

This Tandem arrangement requires a drooped nose in order to provide visibility to both the trainee and the trainer (which was not seen in MiG 21 trainers). A similar requirement is needed for even the single seater carrier based regular fighters. A special circumstance for carrier based aircraft is their AOA while landing could be higher than usual (requiring again a drooped nose for better visibility) and controls have to be more responsive and agile.That is the reason the Naval LCA, Naval LCA trainer, the regular LCA trainer all look alike. The major difference between the naval versions and land based version of the trainers or regular fighteres is, the carrier based versions have strenghtened frame, little longer and structurally stronger under carriage.

Gurus can alter or add to the above.

Kartik · Post by **Kartik** » 19 Aug 2010 00:27

Telang wrote: This Tandem arrangement requires a drooped nose in order to provide visibility to both the trainee and the trainer (which was not seen in MiG 21 trainers). A similar requirement is needed for even the single seater carrier based regular fighters. A special circumstance for carrier based aircraft is their AOA while landing could be higher than usual and controls have to be more responsive and agile.That is the reason the Naval LCA, Naval LCA trainer, the regular LCA trainer all look alike. The major difference between the naval versions and land based version of the trainers or regular fighteres is, the carrier based versions have strenghtened frame, little longer and structurally stronger under carriage.

Gurus can alter or add to the above.

Telang, there is no mandatory requirement for a drooped nose for a combat trainer with tandem seating. It is considered a useful feature (again its a general thumb rule and nothing written on stone, as it depends on customer requirements) to have a 10 to 15 deg slope down from the rear seater's eye-line to the front seater's eye-line.

That requirement is to allow the rear seater to be able to see out the front. Gripen B/Ds for instance do not follow this thumb rule and have very restricted forward visibility for the rear seater and while the F-16B/D/F has no slope either, visibility is better thanks to the construction style of the canopy.

Now, the primary consideration was to keep maximum commonality between N-Tejas and the twin seat Tejas since both were on the drawing boards at that time and that way you can design one forward fuselage and with minimal changes to remove the rear seat and change the canopy, you are done with both the N-Tejas and Tejas twin seater forward fuselage design.
Now, the N-Tejas required a drooped nose so that the pilot had good visibility over the nose when approaching the carrier. That way he could till the last minute have a clear view of where he needed to drop the aircraft to catch the arresting wires. Now, since the N-Tejas had to have the drooped nose, the Tejas twin seat followed a similar path. The drooped nose meant that the design of the tandem cockpit for the Tejas trainer became that much easier since it almost followed in a smooth straight curve as that of the nose.

Now, if there was no need to have similar forward fuselage for the N-Tejas and Tejas twin seater (for instance if there was no N-Tejas), then I'd have expected that they'd keep the design changes on the Tejas twin seat to a minimum (it costs money to design and also money for the necessary tool and jig changes, etc.) and gone with a design similar to the Gripen B/D. Then, the Tejas twin-seater would've looked like the Tejas wind tunnel model shown in the pic below, with the black part representing the canopy for 2 pilots.

As can be clearly seen, it would've had less forward visibility for the rear seater but it keeps costs down.

Tejas wind tunnel model

Avinandan · Post by **Avinandan** » 19 Aug 2010 01:59

my only nitpick with the LCA trainer is that there should have been a full obstruction free canopy without any frames in between

.
Quite similar to twin seat Eurogihter.

Question to gurus: How difficult is to manage that, even F-16 D doesn't have that.

Kartik · Post by **Kartik** » 19 Aug 2010 02:04

Avinandan wrote:my only nitpick with the LCA trainer is that there should have been a full obstruction free canopy without any frames in between .
Quite similar to twin seat Eurogihter.

why ? what advantage does that offer except to remove on obstruction from the rear seater's view ?

bird strike requirements are such that if you don't have a frame to stiffen the canopy, you'll need a thicker canopy glass which will likely weigh more than having a frame.

Avinandan · Post by **Avinandan** » 19 Aug 2010 02:13

Thanks for the reply Kartik, having an obstruction free canopy is a good thing but shouln't be on the cost of weight etc.
Dont want to start a lame argument here, but if that would have been the case, don't you think those guys would have been prudent enough to put the regular canopy in Eurofighter ?

putnanja · Post by **putnanja** » 19 Aug 2010 02:41

Avinandan wrote:Thanks for the reply Kartik, having an obstruction free canopy is a good thing but shouln't be on the cost of weight etc.
Dont want to start a lame argument here, but if that would have been the case, don't you think those guys would have been prudent enough to put the regular canopy in Eurofighter ?

The LCA is a bit underpowered in some flight regimes as it exists today. Adding a heavier canopy isn't going to help any. The EF isn't underpowered, and it was designed with that canopy, so it is already accounted for.

Kartik · Post by **Kartik** » 19 Aug 2010 03:14

Avinandan wrote:Thanks for the reply Kartik, having an obstruction free canopy is a good thing but shouln't be on the cost of weight etc.
Dont want to start a lame argument here, but if that would have been the case, don't you think those guys would have been prudent enough to put the regular canopy in Eurofighter ?

dont know what their exact requirements were. since the rear seater in the Typhoon sits at nearly the same eye level as the front seater, he has already got very little forward visibility. maybe for them the frame would've been another obstruction as well, which would've made visibility in the forward 2 o'clock and 10 o'clock arc more restricted..

anyway, having a large single piece canopy requires quite a bit of engineering finesse.

The processes involved in producing a defect free cockpit canopy are delicate and complex and the Eurofighter canopy design is one of the most demanding in the military aircraft industry. It is one of the largest single piece canopies in production measuring 2.6 metres for the single seat and 2.7 metres long for the twin seat variant. It also marks a watershed in transparency design in that it has to absorb significantly higher aerodynamic loads, making it play a greater structural role.

link

read the link, it gives an idea of how the canopy is manufactured. it also mentions that the cast acryllic billets are 2m long and 50 mm thick, which is nearly 1.96 inches thick. once the 2 m long billet is stretched to 3m long, the thickness will obviously reduce, but since I have no details on the properties I can only presume it will be more than 1inch thick even after stretching. That is quite a thick canopy..for reference sake, the F-16's canopy is believed to be about 1 inch thick.

basically, if you want to resist bird strike at medium to high speeds then its better to have a frame. Combined with a relatively thick canopy it'll ensure that the bird strike doesn't smash the canopy and kill the pilot or disable him enough for him to lose control of the fighter.

rgsrini · Post by **rgsrini** » 19 Aug 2010 04:09

Avinandan wrote:Dont want to start a lame argument here, but if that would have been the case, don't you think those guys would have been prudent enough to put the regular canopy in Eurofighter ?

Don't want to start a lame argument here as well... but if obstruction free canopy is so crucial for the stated purpose, don't you think that our guys would have been prudent enough to put the obstruction free canopy in LCA?

shiv · Post by **shiv** » 19 Aug 2010 07:22

rgsrini wrote:
Avinandan wrote:Dont want to start a lame argument here, but if that would have been the case, don't you think those guys would have been prudent enough to put the regular canopy in Eurofighter ?

Don't want to start a lame argument here as well... but if obstruction free canopy is so crucial for the stated purpose, don't you think that our guys would have been prudent enough to put the obstruction free canopy in LCA?

No. Indians are stupid. Westerners are clever. I can judge the visibility from the LCA canopy just by surfing the net.

sawant · Post by **sawant** » 19 Aug 2010 07:27

Yaaro LCA is a mig-21 replacement why put so many expectations on the kid's airframe. Baccha hai abhi se dont bend the pylons down. Instead let's do some hand-holding and ensure all equipment and electronics and weapons integration is fine. Then we can keep tinkering till it changes from baby-faced Shahid to Salman... or when it comes to the canopy ...from jaya pradha to Katrina... before the aesthetics there's so much to be done...

prastor · Post by **prastor** » 19 Aug 2010 10:56

I agree Sawant. LCA is supposed to be a cost effective replacement of MiG21 with high roll out (per annum) as compared to other fighters in our inventory. Expecting every new feature out in the market from a cheap workhorse is not really logical.

By the way, what is the per unit cost of a MiG 21 Bison?

Rahul M · Post by **Rahul M** » 19 Aug 2010 13:11

@ sawant, please understand that everyone who reads this thread might not understand hindi.
please stick to normal english.

Telang · Post by **Telang** » 19 Aug 2010 13:29

Kartik Guru Jee, I mentioned somewhere earlier that, to understand, my posts need to be translated into English. Thank you for doing just that, even I can understand my post now.

Telang · Post by **Telang** » 19 Aug 2010 13:59

Let me give scope for some nitpicking and keep the thread busy and active with jump-start reactions.

For those who are expecting LCA to be JSF or F22, please understand that the entire Air Force need not be made up of just Su30MKI, there are specific roles for fighters with lesser efficiency. Though LCA is multi role, the basic role is interception and probably ground support. In some theatres where air superiority is achieved, LCA will have excellent performance. For the fighter of this size, combat radious, limitations of weapon load are constraints, but with better Radar, powerful engine, midair refuelling, BVR apability, data-link, stealth, ECM, and ECCM, etc. if incorporated, a lot can be done by these small but potent birds. So, just have patience, this bird is going to be as famous as the Gnat was in 1965 war, or even more. I predict war clouds gathering by 2014, and by then the Tejas will be ready IN ALL RESPECTS to draw first blood. Please shoot.

RKumar · Post by **RKumar** » 19 Aug 2010 16:53

Telang wrote:I predict war clouds gathering by 2014

What you know, which others dont know ... mind sharing with us

Kartik · Post by **Kartik** » 19 Aug 2010 21:14

Well people, if you read the oldest literature regarding the LCA, you'll find that its primary role was described as being offensive air support. The air defence role was secondary. Of course, by design the LCA seems like it'll do a good job at both.

AnuragK · Post by **AnuragK** » 19 Aug 2010 21:59

DELETED.

S_Pawar · Post by **S_Pawar** » 19 Aug 2010 23:46

Kartik wrote:Well people, if you read the oldest literature regarding the LCA, you'll find that its primary role was described as being offensive air support. The air defence role was secondary. Of course, by design the LCA seems like it'll do a good job at both.

But then Karthik sir isnt that the whole reason why the needs for the IAF kept changing over time which in turn caused the delay of tejas induction (as per DRDO). The times when the first literature was formulated our regional ambitions were limited but now as we grow so does the scope for our Air force.
My humble point here is the air defense role is a must for an aircraft that is going to be the backbone of our airforce in the years to come.

Telang · Post by **Telang** » 19 Aug 2010 23:50

This is OT...

S_Pawar · Post by **S_Pawar** » 20 Aug 2010 00:00

This is also OT.

Kartik · Post by **Kartik** » 20 Aug 2010 00:09

S_Pawar wrote:
But then Karthik sir isnt that the whole reason why the needs for the IAF kept changing over time which in turn caused the delay of tejas induction (as per DRDO). The times when the first literature was formulated our regional ambitions were limited but now as we grow so does the scope for our Air force.
My humble point here is the air defense role is a must for an aircraft that is going to be the backbone of our airforce in the years to come.

I'm no sir and not Karthik either..there's another poster by that name.

I was simply stating that the original ASRs from which the Tejas LCA sprung stated that it was meant to be a replacement for the MiG-21 in the close air support role, with its own air defence capability.

Kartik · Post by **Kartik** » 20 Aug 2010 00:49

Just to check whether this was known or not, can anyone guess what 2 aircraft the Soviet Union was offering to India if the LCA program was scrapped ? The answer is quite interesting.

Gaur · Post by **Gaur** » 20 Aug 2010 01:05

^^
Mig LFI and Su-37?

Rahul M · Post by **Rahul M** » 20 Aug 2010 01:08

mig-33, the single engined mig-29 that led to the JF17. I didn't know there was another.

AnuragK · Post by **AnuragK** » 20 Aug 2010 01:32

Last edited by Rahul M on 19 Aug 2010 22:34, edited 3 times in total.
read the first post of this thread. I suggest that you restrict posting to the newbie thread for the moment and cut that arrogance by a fair margin, if you want to stay here that is. this is my last informal warning to you. you already have one.

I have definitely read the first post of this thread. There was no comparison to any other aircraft - charecteristics, specs, or otherwise. Also, there were no suggestions for any additions, alterations, etc. in the a/c. Further, there was nothing pugnacious in the post about the aircraft or toward any poster.

While deleteing is your prerogative, courtesy demands that you explain the reasons thereof in the light of the above. Please do have a second hard look at the post of which you should be having a copy even if deleted here.

What arrogance are you talking about????

Kartik · Post by **Kartik** » 20 Aug 2010 01:44

Gaur wrote:^^
Mig LFI and Su-37?

which LFI are you referring to ? and which Su-37 ?

Kartik · Post by **Kartik** » 20 Aug 2010 01:46

Rahul M wrote:mig-33, the single engined mig-29 that led to the JF17. I didn't know there was another.

they apparently did offer the single engined MiG-33 variant that was the precursor to the JF-17, but they also offered the MiG-30 ! Apparently it was a ground-attack capable MiG-29 variant.

A Sukhoi variant was also offered..am really intrigued by the description of this one..

Gaur · Post by **Gaur** » 20 Aug 2010 02:12

Kartik wrote:
Gaur wrote:^^
Mig LFI and Su-37?
which LFI are you referring to ? and which Su-37 ?

LFI is the Mig-33 RahulM is reffering to.I read about it being offered to India in this thread itself. Su-37 is the TVC Su-27 from which MKI was derived. But now thinking about it, it was pretty stupid of me to suggest Su-37 considering that it is a heavy twin engined fighter. But I do seem to remember reading it being offered to India in some forum. But I must admit that it now seems unlikely. But then again, Su has not proposed a single engined prototype for a long time. So, aside from Su-37, I cannot guess any other fighter being offered to India by Sukhoi.

krisna · Post by **krisna** » 20 Aug 2010 02:15

Kartik wrote:Just to check whether this was known or not, can anyone guess what 2 aircraft the Soviet Union was offering to India if the LCA program was scrapped ? The answer is quite interesting.

is it the MIG -35
source--MiG-35

According to unidentified Indian sources the aircraft was evaluated by Indian pilots in the Soviet Union and was probably suggested as an alternative for the Indian LCA being developed at that time.[6]

(6)=Jane's Defence Weekly, 13 August 1988, p. 235

Kartik wrote:
Rahul M wrote:mig-33, the single engined mig-29 that led to the JF17. I didn't know there was another.
they apparently did offer the single engined MiG-33 variant that was the precursor to the JF-17, but they also offered the MiG-30 ! Apparently it was a ground-attack capable MiG-29 variant.

A Sukhoi variant was also offered..am really intrigued by the description of this one..

Mig-33 engine was rejected by the russians but it was taken ?stolen by chinese for their a/c

Rahul M · Post by **Rahul M** » 20 Aug 2010 02:23

they had an even numbered mig ! my interest is piqued ! now that you mention it, I do vaguely remember something about a GA mig-29 being thrown about. never knew it was called mig-30.

sukhoi variant of what, do you mean a flanker variant ?

________________

no gaur, LFI is a much later day project. it stood for light frontal interceptor and along with MFI formed the russian response to the F-22/JSF.
both LFI and MFI were 5gen projects. s-37 and mig 1.42/1.44 were the MFI proposals, I-2000 was the mig LFI proposal (never moved beyond drawing board) and sukhoi had a prototype based on a trainer, s55 or something. both MFI and LFI were eventually canceled and PAKFA was launched.

suryag · Post by **suryag** » 20 Aug 2010 02:26

ada org chart

Look at the org chart of individual departments on the left side, doesnt it look a little top heavy, lots of scientist f's
on the brighter side there is a clear cut division of work and there is a wealth of information on each of the departments responsibilities and progress. Needs a proper web designer though. Btw, the project management team PMG is understaffed and the navy pmg team is bigger than the overall pmg team which goes to show how much importance the navy is according to the lca navy program.Didnt find any deployment and customer interfacing team to deal with deployment at Sulur. I also like the fact that they have a systems team to look at various systemic aspects.

They also have project teams for Aura and AMCA, it is nice to see the same. In fact ADA is one of the DRDO orgs that has delivered despite all odds, hope we expand this great team and have an other ADA mirrored on this in some other city to work on transport aircrafts.

The org chart itself speaks about the program's maturity and it doesnt look much like that of an R&D org and looks more like that of a private company. We should not fritter away the gains from this project at any cost. Now waiting for that LSP5 to fly it is 20th already

Gaur · Post by **Gaur** » 20 Aug 2010 02:41

Rahul M wrote: no gaur, LFI is a much later day project. it stood for light frontal interceptor and along with MFI formed the russian response to the F-22/JSF.
both LFI and MFI were 5gen projects. s-37 and mig 1.42/1.44 were the MFI proposals, I-2000 was the mig LFI proposal (never moved beyond drawing board) and sukhoi had a prototype based on a trainer, s55 or something. both MFI and LFI were eventually canceled and PAKFA was launched.

I see. I thought that MIG LFI and Mig-33 were one and the same. Thanks for the correction.

Indranil · Post by **Indranil** » 20 Aug 2010 03:03

Kartik wrote:
A Sukhoi variant was also offered..am really intrigued by the description of this one..

Was it the S-55?

P.S. Rahul M had already spoken about it.

Kartik · Post by **Kartik** » 20 Aug 2010 04:36

Rahul M wrote:they had an even numbered mig ! my interest is piqued ! now that you mention it, I do vaguely remember something about a GA mig-29 being thrown about. never knew it was called mig-30.
sukhoi variant of what, do you mean a flanker variant ?

Even I couldn't believe it when I read it on Flight Global's archived news articles.

Apparently they offered the MiG-30 and the "Su-37" which was a single seat Gripen-like canard delta fighter with a single Al-31 engine, not a Flanker variant at all..that really interested me since I couldn't recall having read about it earlier..it was stated that this was a paper design, but if India expressed interest it could be prototyped within a couple of years.

BTW, the original MiG-35 was the single seat, single engined F-16 equivalent that later on formed the basis of the JF-17. The term MiG-33 is also sometimes used for the same design.

If you look for the year 1988 in Flight's archives, you'll find an article where India refuted Janes Defence Weekly reports that it would transfer technologies to Russia to help it build the MiG-35 (yes, the accusation was that India was transferring technologies to Russia !) and that it had test flown a MiG-35, saying that no such fighter existed.

Kartik · Post by **Kartik** » 20 Aug 2010 04:50

Kartik wrote: Now, if there was no need to have similar forward fuselage for the N-Tejas and Tejas twin seater (for instance if there was no N-Tejas), then I'd have expected that they'd keep the design changes on the Tejas twin seat to a minimum (it costs money to design and also money for the necessary tool and jig changes, etc.) and gone with a design similar to the Gripen B/D. Then, the Tejas twin-seater would've looked like the Tejas wind tunnel model shown in the pic below, with the black part representing the canopy for 2 pilots.

As can be clearly seen, it would've had less forward visibility for the rear seater but it keeps costs down.

Tejas wind tunnel model

amazingly enough, I just found a very rare picture of the LCA twin-seater dating back to 1990 from Flight International !

It shows the twin seater design as it was anticipated to look like back then and guess what ?! I was right about how the twin seater would have looked if there was no N-LCA design influencing the drooped nose ! there is no pronounced slope to the cockpit and the rear seater has much less forward visibility, similar to the Typhoon, F-16 or Gripen twin seaters.

Flight Global article from 1990 on LCA

D Roy · Post by **D Roy** » 20 Aug 2010 06:33

OT but,

For these things Paralay's site is always the best bet ...

http://paralay.com/lfi_su.html

http://paralay.com/lfi_mig.html

http://paralay.com/s56.html

Kartik · Post by **Kartik** » 20 Aug 2010 07:06

the S-37 is described on the secretprojects page

link

S-37 picture

Rahul M · Post by **Rahul M** » 20 Aug 2010 09:22

interesting kartik, I wonder if this led to the s-55 later. http://www.militaryphotos.net/forums/sh ... ghter-S-56

I just remembered that IAF rejected the ground attack mig-29 proposal because it was considered too short-legged.