LCA: News & Discussions: 15 August 2017

ks_sachin · Post by **ks_sachin** » 09 Jan 2018 15:16

JayS wrote:
ks_sachin wrote:
Thanks Indranil,

Are we talking about the same thing? I am talking about the area where the upper part of the wing meets the fuselage and then continues to the spine. I am especially interested in the area behind the canopy and forward of the intake in front of the tail. To my rather ageing eyes could the bleeding be smoother?

Indulge me. I am reading up on all that you are point me at..
IR is referring to exactly that area. Its the fuselage-wing blending. Well, I also do not like the blending on LCA all that much. It could be much better. But this one is LSP. SPs have much better build quality and are somewhat easier on eyes. I expect MK2 to have much better blending in general, similar to Rafale or Gripen.

The transonic drag part you mentioned, which will be taken care of by the plug, is near the canopy. The proposed plug is going to be placed between the back of the canopy and the start of the wing. Read following paper to see where the discontinuity lies in the area curve (original link on NAL server seems dead).

http://studyres.com/doc/22195794/influe ... g-of-a-gen...

Thanks Jay may be I got the transonic bit wrong. I suppose question was whether that blending was optimal from a drag perspective.

JayS · Post by **JayS** » 09 Jan 2018 16:05

^^ If you ask me, IMO its not optimal, could be better. Not only on the top but on the bottom side as well. But we have to consider the fact that its designed in lates 80s/early 90s. The design technology at that time available for ADA was limited. They have literally built the capability from scratch. So we can give them some leeway. But I would expect MK2 to do better.

PS: But take my opinion FWIW. Its nigh impossible to say with certainty without looking at WT data or simulation results or flight testing results.

ks_sachin · Post by **ks_sachin** » 09 Jan 2018 16:27

JayS wrote:^^ If you ask me, IMO its not optimal, could be better. Not only on the top but on the bottom side as well. But we have to consider the fact that its designed in lates 80s/early 90s. The design technology at that time available for ADA was limited. They have literally built the capability from scratch. So we can give them some leeway. But I would expect MK2 to do better.

Thanks mate.

Rakesh · Post by **Rakesh** » 09 Jan 2018 18:03

ks_sachin wrote:
Akshay Kapoor wrote:
I have been saying for a while that LCA flight is just taking off and there are big positives ahead
Now the icing on the cake will be someone officially burying that stupid SEF thingy!!

Best post of 2018 to date! Thanks IR. And Sachin Saar, I could not agree more. End this SEF competition. Utter waste of money.

JayS · Post by **JayS** » 09 Jan 2018 18:38

Indranil wrote:There was some great zaika in the chai today. AMCA and Mk2 has been sanctioned. Hopefully funds will also start to flow in soon.

ye news sun ke toh Dil Lalbagh Lalbagh ho gaya..

AMCA approval was eminent and was hinted by a few sources. But MK2 is real bonus with the kind of things were happening. Now its clear, why so much tamasha was going on against Tejas.

SaiK · Post by **SaiK** » 09 Jan 2018 18:47

Akshay Kapoor wrote:
Indranil wrote:There was some great zaika in the chai today. AMCA and Mk2 has been sanctioned. Hopefully funds will also start to flow in soon.
I have been saying for a while that LCA flight is just taking off and there are big positives ahead

OK.. I need to make my claims then. I keep constantly bugging Sitaraman ji.

nam · Post by **nam** » 09 Jan 2018 19:59

I hope HAL is involved in MK2 design. They need to take it over the full development and production of MK2 & Mk3 etc.

ADA needs to go full steam on AMCa & UCAV.

Zynda · Post by **Zynda** » 09 Jan 2018 20:11

Great news on Mk.2 front. So who will assume ownership of Mk.2? ADA or HAL? Will it be HAL but still majority of the design is handled (if not done) by ADA? I hope this renewal will bring in some new opportunities for young engineers.

ArjunPandit · Post by **ArjunPandit** » 09 Jan 2018 20:57

kancha wrote:
ArjunPandit wrote:
On a serious note I was thinking of learning basic physics of a fighter jet ...any recommendations for basic physics from Jay, want to start with some basic and preferably with numericals
'Flight Without Formulae' by AC Kermode is a masterpiece. Written before WW2, it remains one of the best books to understand basic aerodynamics. I read it before I took up aeromodelling exactly one decade ago.
But as the name suggests, it is without numericals .. so I'm not quite sure whether it will meet your needs.
A quick google search shows pdf versions available for download. May have a look

Thanks Kancha, while looking for this book, I got another book (Mechanics of flight), which was exactly what I was looking for

ArjunPandit · Post by **ArjunPandit** » 09 Jan 2018 20:58

SaiK wrote:
Akshay Kapoor wrote:
I have been saying for a while that LCA flight is just taking off and there are big positives ahead
OK.. I need to make my claims then. I keep constantly bugging Sitaraman ji.

Great job sir, kudos to you, I think we all should follow this for Arjun. Who knows we might get lucky there too

ArjunPandit · Post by **ArjunPandit** » 09 Jan 2018 21:00

Zynda wrote:Great news on Mk.2 front. So who will assume ownership of Mk.2? ADA or HAL? Will it be HAL but still majority of the design is handled (if not done) by ADA? I hope this renewal will bring in some new opportunities for young engineers.

This is very very good news. What will be more important is if
1. IAF is involved right from the start to the fullest extent possible
2. Feedback from Flying daggers is incorporated in design. There is nothing like user feedback to design

Karan M · Post by **Karan M** » 09 Jan 2018 21:52

This is excellent news! Since its from Indranil, accuracy factor is assumed to be 100%. Which brings us to the next question, where is dilbu to do the anti-jinx formula.

Indranil · Post by **Indranil** » 09 Jan 2018 21:57

Mk2 is ADA’s bird. MK1A is HAL’s. I just hope they talk.

ramana · Post by **ramana** » 09 Jan 2018 21:59

Zynda wrote:Great news on Mk.2 front. So who will assume ownership of Mk.2? ADA or HAL? Will it be HAL but still majority of the design is handled (if not done) by ADA? I hope this renewal will bring in some new opportunities for young engineers.

ADA for the design and HAL for the production.

Its like a relay race.
Once design is over HAL takes up the production. Off course concurrent engineering will be there.

JayS · Post by **JayS** » 09 Jan 2018 22:10

ramana wrote:
Zynda wrote:Great news on Mk.2 front. So who will assume ownership of Mk.2? ADA or HAL? Will it be HAL but still majority of the design is handled (if not done) by ADA? I hope this renewal will bring in some new opportunities for young engineers.

ADA for the design and HAL for the production.

Its like a relay race.
Once design is over HAL takes up the production. Off course concurrent engineering will be there.

HAL has designed some 17 or 19 of the 21 modules of LCA...!!! (In one of the videos TSR mentioned this - in think, in the Coupta's Walk the talk show) They could take over Mk1 and offer Mk1A just like that, because of their deep involvement in LCA design. I doubt HAL could do this for Su-30MKI.

Haridas · Post by **Haridas** » 09 Jan 2018 22:26

ArjunPandit wrote:What will be more important is if
1. IAF is involved right from the start to the fullest extent possible

One can take the horse to water but can't force it to drink if it does not want to drink.

IAF has officer position that don't stay on the job more than one posting. Unless it now opens a new outfit that has stake keepers that stays on saddle for a very long time (say 10 years). Wishful thinking imho.

ramana · Post by **ramana** » 09 Jan 2018 22:46

Jays,

If you read AM Wollen"s article, the entire ADA design team was from HAL.

Vivek K · Post by **Vivek K** » 09 Jan 2018 22:47

So finally we are getting our feet back on the ground. Also India/IAF have decades of experience with imports and I suspect that Roosi and French hardball have made them look afresh at ghar ki murgi or murga. There is simply no other option without bankruptcy and leading to decreased security.

The new RM seems to be good and I hope she continues with her sensible actions.

ramana · Post by **ramana** » 09 Jan 2018 22:53

I said on Twitter, Sitharaman is the best peacetime RM India uas had. And hoped they don't test her to see how she does in war.

kancha · Post by **kancha** » 09 Jan 2018 23:55

ArjunPandit wrote: Thanks Kancha, while looking for this book, I got another book (Mechanics of flight), which was exactly what I was looking for

Happy to help .. even if inadvertently

dkhare · Post by **dkhare** » 10 Jan 2018 00:21

Indranil wrote:There was some great zaika in the chai today. AMCA and Mk2 has been sanctioned. Hopefully funds will also start to flow in soon.

Indranil - wonderful news. Will look for official confirmation...

Hopefully, funds will be allocated and released as soon as possible. Hon. Raksha Mantri must get all parties (ADA+HAL+IAF) involved to come together, cooperate, and go into mission mode to achieve aggressive time lines.

Kakkaji · Post by **Kakkaji** » 10 Jan 2018 00:34

SaiK wrote:
Akshay Kapoor wrote:
I have been saying for a while that LCA flight is just taking off and there are big positives ahead
OK.. I need to make my claims then. I keep constantly bugging Sitaraman ji.

Three cheers for SaiK Ustaad

dkhare · Post by **dkhare** » 10 Jan 2018 00:42

JayS wrote:^^ If you ask me, IMO its not optimal, could be better. Not only on the top but on the bottom side as well. But we have to consider the fact that its designed in lates 80s/early 90s. The design technology at that time available for ADA was limited. They have literally built the capability from scratch. So we can give them some leeway. But I would expect MK2 to do better.

PS: But take my opinion FWIW. Its nigh impossible to say with certainty without looking at WT data or simulation results or flight testing results.

Just a humble opinion/observation:
I too think there is scope for optimizing the bottom part of the wing - fuselage joint. I think there was talk on BRF of moving the main landing gear out of the fuselage and into the wing root join and make that bottom wing - fuselage blending more smooth like the Rafale. It will add space for fuel as well. However, these changes need to be considered, if and only if, it does not change the CG too much and the FCS changes are minimal and within parameter limits. Any major changes involving the FCS will require significant re-testing and inevitably lead to delays.

Zynda · Post by **Zynda** » 10 Jan 2018 02:00

Indranil wrote:Mk2 is ADA’s bird. MK1A is HAL’s. I just hope they talk.

IR are you aware if NAL will continue to be primary design consultant for Mk.2? This may be a more challenging to get answers...but does ADA see greater participation from Indian Private sectors in Engineering apart from production for Mk.2?

I am probably stretching too much here but I am hoping that ADA/NAL will act as mentors and subsystems manufacturers (say for Ex Dynamatic) they could do engineering as well as fabrication before sending it to HAL for integration. Essentially creating various subsystem org who could take up the challenge & gain experience (ultimately expertise) in designing various individual subsystems...like how various org. contributed to B787 (Mitsubishi etc.)

Having mentioned the above, I also doubt such a significant role would be involved in Mk.2 as it would delay the program...

Trikaal · Post by **Trikaal** » 10 Jan 2018 02:21

If funds are quickly alloted, it might be possible for first flight of Mk2 by 2021

Cain Marko · Post by **Cain Marko** » 10 Jan 2018 02:27

Aditya_V wrote:
Indranil wrote:There was some great zaika in the chai today. AMCA and Mk2 has been sanctioned. Hopefully funds will also start to flow in soon.
Any link or Official news

How soon can we expect this news to be out. Well, better MIIF than SEF.

I'm liking Madam Sitharaman more and more with every passing day, even more than MP

Kartik · Post by **Kartik** » 10 Jan 2018 02:54

Indranil wrote:There was some great zaika in the chai today. AMCA and Mk2 has been sanctioned. Hopefully funds will also start to flow in soon.

This news made my day! Now for some official report on this to confirm that the funds are flowing through as well.

Kartik · Post by **Kartik** » 10 Jan 2018 03:00

suryag wrote:I still dont see as many Tejas taking off as i would expect given the flogging that the first batch of SU-30Ks got or may be they are out practicing at other locations. Meanwhile, had one question in general about trainers and their place in the squadrons. We have/had MOFTUs where MiG pilots would fly trainers and then goto operational squadrons, havent heard of JOFTUs, essentially, what am looking for is do trainers become part of operational squadrons like M2K squadrons or they become some OFTUs and what would this be in the case of Tejas. I hope the first squadron is flogging their birds so that entire logistics and maintenance requirement and corresponding impact on the supply chain is worked out while they are in BLR

They're being flogged alright. The video of NO.45 Squadron has one of the pilots mentioning that over 4000 flights have occurred and that video was a while ago..it implied that over 400 squadron flights had occurred, that too with a fleet size that incrementally has grown to just about 5.

But OTOH, the Su-30K was essentially a non-upgraded Su-30. It wasn't a new type that was still in development, or entering service for the first time. Su-27 variants had been in service for over a decade and most issues would've been resolved during that time..unlike the Tejas which is now for the first time entering service anywhere, so its natural to see some issues that may keep the fleet on the ground for a while.

But I'd expect the fleet to see an average utilization of ~100 hours per year at the very least, which is respectable.

srai · Post by **srai** » 10 Jan 2018 03:22

^^^
LCA Simulator based training would also reduce the number of hours required for actual flying when compared with the older planes like Su-30K.

Kartik · Post by **Kartik** » 10 Jan 2018 03:22

deejay wrote:
ks_sachin wrote:deejay sir,
I presume MOFTU is still operational. Once the Mig are out will that be mothballed or do you see that morphing into some thing else. Also Wiki chacha says MOFTU imparted Stage 3 trng on the Mig 21's. What about the other Migs or other fighter aircraft?
Not updated on the MOFTU status Sir.

Training is part of every Sqn duties.

At MOFTU, syllabus flying in CAP etc role are completed. I do not have more details to write with authority on this.

Deejay sir, MOFTU closed in 2007, with the last MiG-21FL flight from Tezpur.

link

GUWAHATI: The magnificent MiG 21 aircraft will fly no longer from the Indian Air Force Station at Tezpur. The Air Force station on Thursday conducted a farewell ceremony to mark the occasion.

According to official statement, it was on February 27, 1986 that the first MiG 21(FL) , also known as MiG-21(T-77), landed at Tezpur Air base, thus marking the beginning of the supersonic era.

Since then, the Air Force station at Tezpur has been a home to this aircraft, and over a period of time, has become synonymous with MiG-21(T-77).

..

On December 15, 1986, the MiG Operational Flying Training Unit (MOFTU) was thus born at Air Force Station, Tezpur.In 2003, MOFTU, because of its huge size, was bifurcated into two independent units, ‘Alpha’ and ‘Bravo’, or aggressors and bravehearts, for administrative efficiency.

Over the last four years, both these squadrons did a splendid job of imparting quality training to budding pilots. However, last year, Operational Conversion Unit (OCU) and MOFTU ‘Bravo’ were relocated from Tezpur to other bases in the Eastern Air Command.

Now in September, MOFTU ‘alpha’ will also get relocated to another base within the command. With this, Tezpur Air base will fade into history as the cradle of young fighter pilots and bastion of type 77 operations.

The programme will include various ceremonial activities to be conducted by the Air Warriors, KV school children, cultural groups from Tezpur and the Army unit of 4 Corps. This will be followed by a goodbye flypast by the MiG 21(T-77) aircraft.
..

And MiG-21FL fighters were retired in 2013. So that, the MiG-21FLs that served at MOFTU and then were relocated to another base, would have also been retired.

srai · Post by **srai** » 10 Jan 2018 03:24

^^^
Perfect time to restart OFTU with Tejas Mk.1. Get 40 more!

Kartik · Post by **Kartik** » 10 Jan 2018 03:45

Yes indeed, a LIFT variant of the Tejas trainer is a low hanging fruit, if the IAF feels that LIFT serves some purpose. the Hawk serves well as an AJT, and is economical on a per hour basis, but cannot fly supersonic and cannot as yet replicate the cockpits of all IAF aircraft. HAL/BAe's Hawk-i upgrade proposed synthetic training aids and improvements in performance, so it will be competing with any proposed new build Tejas LIFTs.

But there is no doubt that the Tejas is a high performance fighter and in that respect, far better suited to giving rookie pilots a taste of fighter flying, than the Hawk or even Hawk-i will be.

Since a Tejas LIFT doesn't need to have the sort of weapons or some of the avionics of even a Tejas Mk1 trainer, if the IAF does want to go ahead with it, the SOP could be frozen pretty fast. HAL would need to work on the synthetic training/simulation and the simulators on the ground aspect that would come as a package with the Tejas LIFT. But it will provide very valuable experience in a field where the Tejas could have secured a lot of business, since the level of sophistication of on-board avionics and weaponry was minimal. Much of it has been now sealed by T-50 variants and the M-346 Master. But I guess money making wasn't one of the goals of the Tejas program, at least not until now, where private sector contractors and sub-contractors will be more interested as more orders come in.

ks_sachin · Post by **ks_sachin** » 10 Jan 2018 04:07

Indranil / Jay

Both of you have made comments about the imp in build quality from LSP to SP. Can any reduction in friction drag be quantified?

Indranil · Post by **Indranil** » 10 Jan 2018 04:08

I don't think anybody likes the wing-body blending on LCA

. Something makes it not sit pretty with my eyes either. If F-16s/F-15s/F-18s are the benchmark, then LCA's blending is pretty okay. But if the benchmark is Rafale/Mirage 2000/F-22 then there is lot left to be desired.

We had discussed this at length earlier. At that time I had a few problems.

1. When I want to smooth out the join between two orthogonal surfaces, I want to go with a concave join. On the LCA it is near convex.
2. Why is the wing body blending so extravagent on the top and near non existent at the bottom. Why don't they redistribute it more evenly?
3. If the MLG is rooted at the wing join and retreated straight up into the bulgier wing-body join (aka Su-30), wouldn't that give structural simplicity to the MLG, aka less weight?
4. Wouldn't the above config allow an MLG door that opens sideways, decreasing drag?

But these are elementary fixes. What is stopping ADA/NAL scientists from enacting these? I think the answer lies in three parts:
1. Underneath the upper wing-body join lies Tejas's main fuel tank. So convex = more volume. Functionality wise, it does the job.
2. Tejas's wing is mid-set and there is considerable interplay between the airflow around the payload on the inboard pylon and the keel of the fuselage. If they increase the bulge there, the airflow becomes more constricted, i.e. more drag.

I love the LCA Navy Mk2 design. The bottom part still needs some work, but it is halfway there. I don't know why they don't design LCA IAF Mk2 as LCA NAvy Mk2--. Would greatly ease workload!

Indranil · Post by **Indranil** » 10 Jan 2018 04:11

ks_sachin wrote:Indranil / Jay

Both of you have made comments about the imp in build quality from LSP to SP. Can any reduction in friction drag be quantified?

It cannot be eyeballed. At least I can't. More than friction drag, I think the effect on transonic acceleration is more profund.

ks_sachin · Post by **ks_sachin** » 10 Jan 2018 04:25

Indranil,
reading about drag with a single malt was a great experience....

Indranil · Post by **Indranil** » 10 Jan 2018 04:44

Generally, pot and drag are associated more together.

srai · Post by **srai** » 10 Jan 2018 05:01

Indranil wrote:...
I love the LCA Navy Mk2 design. The bottom part still needs some work, but it is halfway there. I don't know why they don't design LCA IAF Mk2 as LCA NAvy Mk2--. Would greatly ease workload!

Yes, that has also crossed my mind. Why two completely separate designs? Take LCA Navy Mk.2 as a baseline and then modify for AF i.e. remove carrier landing features.

Cybaru · Post by **Cybaru** » 10 Jan 2018 05:24

^^ Taking the NLCA mk2 and using that for IAF mk2 was always the initial plan circa 2011/2013 (AeroIndia-reports by some of you). Not sure how it morphed into a different size plug for IAF and IN. They don't have bandwidth for two different designs. They need to work on one and only one Mk2 and satisfy both forces with it.

ArjunPandit · Post by **ArjunPandit** » 10 Jan 2018 05:56

Kartik wrote: They're being flogged alright. The video of NO.45 Squadron has one of the pilots mentioning that over 4000 flights have occurred and that video was a while ago..it implied that over 400 squadron flights had occurred, that too with a fleet size that incrementally has grown to just about 5.

Nobody here notices it anymore, compare that with the fact that 1000-2000 flights were completed from 2009-2013 (i understand that the number of planes doesnt make it comparable) and every flight count was tracked here by which plane flew culling info from ADA website...those were days.
Thin