LCA News and Discussions

SaiK · Post by **SaiK** » 20 Jul 2013 21:22

thank you.. yeah the tight turns were my thought. not much there.

Indranil · Post by **Indranil** » 20 Jul 2013 22:05

SaiK wrote:i was thinking the pointier the tip, better is the turn rate because it would aid the stall in tight turns. i could be wrong or perhaps it might lose speed.

I don't understand how a sharper wing tip delays stall?

SaiK · Post by **SaiK** » 21 Jul 2013 02:37

indranil, i got it reversed. pointed tip increases tip stall. never mind. i was reading an article about albatross bird and wing designs... i stand corrected.

http://books.google.com/books?id=HN9zXu ... ps&f=false

talks about albatross's pointed wing tips, enable reduced drag, higher efficiency. natural bird evolution is different anyways.. they have other things on the wings, like feather and wing slots that control may have actually contributed to reduced drag rather the wing tips.

Lalmohan · Post by **Lalmohan** » 21 Jul 2013 03:45

saik - the tips are where the main vortices leave the wing - so when you play around with tip shape you essentially play around with drag due to the way the vortex is shed. many birds have evolved the little winglets you see on airliners - these move the vortex shedding point and guide it to create less drag - and therefore increase range

turning rate is essentially about lift and aoa in the horizontal plane whilst keeping the aircraft in balance

SaiK · Post by **SaiK** » 21 Jul 2013 03:59

perhaps yes.. now i got to understand what i was thinking of turn rate and wing tips. so the question in my mind was, would not the wing-tip end flaps and slats rather lerx be more useful for efficient turns?

SaiK · Post by **SaiK** » 21 Jul 2013 08:15

slightly dated.. but needs validation of this info:

http://defense-update.com/20130206_adva ... kills.html

Originally, the EL/M-2032 was selected but the new 2052 now available with a more compact antenna is best designed to fit the nose cones of LCA and Jaguar, offering enhanced capabilities for both fighters.

why are the media keep harping on AESA for Mk-1.

btw, where the t/rs hiding?

Philip · Post by **Philip** » 21 Jul 2013 12:08

Is it -the 2052 available? I thought that there was some hesitation some time ago about giving us the details/TOT for the same. It would make sense at least for the MK-2,or the follow on 20 of the first batch of 40MK-1s on order. Apart from the Jaguars,why not even use it on the Sea Harriers too,which have operational life in them for another decade at least.

SaiK · Post by **SaiK** » 21 Jul 2013 21:37

given the budget, time and schedule, it is very much feasible to think to go for the 2052 based patch-works rather 2032 based work.. why spend billions for 32 base, and then again another billion for 52. this is essential because as a solution provider, LRDE/HAL combines have failed to deliver a capable radar. so, if we are not re-inventing the wheel for the benefits of indigenization, then we might as well aim for the best available. provided no sanctions?

Manish_Sharma · Post by **Manish_Sharma** » 22 Jul 2013 04:42

Just before Rafale was chosen, US forbade israel to sell 2052 to Hindusthanam!

http://gfilesindia.com/frmArticleDetail ... ER%20STORY

Significantly, the US had put its foot down on the sale of Israel’s Arrow anti-missile defence system to India as this might have hurt Pakistan and helped India develop an indigenous ballistic missile system. More recently, Israel stopped the sale of EL/M-2052 radar to India under intense US pressure. The inside story is that the US wanted to sell its own system to India. The lesson here is that India and Israel can be each other’s friend if Uncle Sam permits. Recently, the names of DRDO and ISRO were removed from the Entity List to allow India to import equipment from the US. This worked. India is now close to purchasing a major US combat-weapon system for the first time in decades.

SaiK · Post by **SaiK** » 22 Jul 2013 04:44

well.. they will not get their share of nuclear reactors and other business for desh then.

that thought should be laid to rest, since neither teens won the mmrca. they should have a different look now.

they might bring back based on iran pipeline deal too. and again, this is totally politics rather than needs.

didn't we also here we were working on the AESA radar for mk-2. that should give them some indication of losing some really good money as well.. plus the market. just announce that indian AESA radar tested successfully out, and see how they come out with offers... just to spoil our efforts, and there are of course our middlemen and firang loving clout who would gubo.

actually, there is nothing stopping us other massans to install the 52s.

suryag · Post by **suryag** » 22 Jul 2013 09:59

Flight update

From
LCA-Tejas has completed 2270 Test Flights Successfully. (15-July-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-366,LSP1-74,LSP2-275,PV5-36,LSP3-155,LSP4-90,LSP5-198,LSP7-51,NP1-4,LSP8-19)

to

LCA-Tejas has completed 2271 Test Flights Successfully. (15-July-2013).
(TD1-233,TD2-305,PV1-242,PV2-222,PV3-366,LSP1-74,LSP2-275,PV5-36,LSP3-156,LSP4-90,LSP5-198,LSP7-51,NP1-4,LSP8-19)

Lalmohan · Post by **Lalmohan** » 22 Jul 2013 12:30

saik - my memory is a bit rusty - but overall - the wingtip is for drag *refinement*, the LERX is to ensure that the wing stays with controlled flow for a higher alpha range - therefore giving it better sustained turn rate.

in all matters related to flight mechanics - everything has an effect on everything else (its a 6DOF model with control effects all the way from x, xdot, xdotdot, xdotdotdot (in each axis of x,y,z)) - its basically a question of - for a given configuration - what gives you the optimum performance which gets you to your design goal for the 'mission'

typically wingtip modifications give the most benefit for drag reduction and hence impact range, wing root and LE modifications give the best impact for lift at different alpha. having controls at the wing tip will give you a higher rolling moment, but may come at the expense of stability and drag (not to mention structural penalties). ailerons are anyway sufficient removed from the cg line to give strong rolling moments - the turn comes from quick roll and yaw into turn position/attitude and then sustaining lift whilst compensating for the drag with thrust (and lots of it) in x,y and z axes

ramana · Post by **ramana** » 22 Jul 2013 22:10

Manish_Sharma wrote:Just before Rafale was chosen, US forbade israel to sell 2052 to Hindusthanam!

http://gfilesindia.com/frmArticleDetail ... ER%20STORY
Significantly, the US had put its foot down on the sale of Israel’s Arrow anti-missile defence system to India as this might have hurt Pakistan and helped India develop an indigenous ballistic missile system. More recently, Israel stopped the sale of EL/M-2052 radar to India under intense US pressure. The inside story is that the US wanted to sell its own system to India. The lesson here is that India and Israel can be each other’s friend if Uncle Sam permits. Recently, the names of DRDO and ISRO were removed from the Entity List to allow India to import equipment from the US. This worked. India is now close to purchasing a major US combat-weapon system for the first time in decades.

They did the same withthe cryogenic engine. General Dynamics wanted to seel just the engines whiel India wanted the technology. So Russians had an engine which needed development. After India signed with the Russians, the US invoked MTCR sanctions etc on Russia to prevent the sale. And gave them some token satellite launhes as baksheesh.

And even claimed ISRO scientists were quitting and joining DRDO. So UR Rao told Al Gore what about the many Indians who quit ISRO and joined NASA! Why not put sanctions on NASA.

Nikhil T · Post by **Nikhil T** » 23 Jul 2013 09:48

Nice article from Col Shukla.
A bird in the hand: induct Tejas Mark I into the IAF in larger numbers

After two decades of development and the expenditure of some 8,000 crore, the Tejas Light Combat Aircraft (LCA) is nearing operational service in the Indian Air Force (IAF). With Final Operational Clearance (FOC) targeted for end-2014, an Indian light fighter would be flying combat missions in any conflict from 2015 onwards,. Given that this is India’s first modern combat fighter, the Aeronautical Development Agency (ADA) --- the Defence R&D Organisation (DRDO) body that oversees the Tejas project --- has developed its debut fighter quickly and cheaply.

It is time to induct the Tejas into the IAF in large numbers, not just to phase out the MiG-21, but also to let line pilots develop confidence in the fighter and allow their feedback to inform further development. But the Ministry of Defence (MoD) has unwisely decided to build just two squadrons of the already developed aircraft --- called Tejas Mark I --- and to start developing an even more capable Tejas Mark II. This is an enormous blunder for at least three reasons.

Firstly, as testified by the IAF test pilots who have flown the Tejas through more than a thousand hours of flight-testing, the current version of the fighter, i.e. the Tejas Mark I, is already a world-class fighter that has achieved most performance landmarks that the IAF had demanded. It flies at Mach 1.6 (about 2,000 kmph), a speed that the IAF is satisfied with. Its state-of-the-art quadruplex digital flight control system makes it a maneuverable and easy-to-fly fighter, unlike the unforgiving MiG-21 that it is slated to replace. The Tejas has not had a single accident so far, testifying to the stability of its design.

Another key measure of a fighter’s capability is the Angle of Attack (AoA) it can achieve. The higher the AoA, the more lift that is generated, allowing a fighter to get airborne at slower speeds from short airstrips, e.g. aircraft carriers. The IAF had demanded an AoA of 26 degrees for the Tejas. The Tejas has already been tested to 24 degrees, and is on course to achieve that target.

Says Air Commodore (Retd) Parvez Khokhar, who was for years the chief test pilot of the Tejas programme: “The Tejas Mark I is far superior to the MiG-21 fleet that the IAF would have to operate to the end of this decade. In key respects, it is a better fighter than even the Mirage 2000. The Tejas Mark I should enter the IAF’s combat fleet in larger numbers and the Tejas Mark II scaled down. This would allow the air force to retire the MiG-21 fleet sooner.”

For this, the MoD must review its current plan to build just forty Tejas Mark I fighters, and embark upon another risky adventure to develop a more powerful, capable fighter. Since this would take at least four years of development work, the IAF would not start receiving the Tejas Mark II until 2018.

Furthermore, developing an ambitiously-framed Tejas Mark II would be dogged by uncertainty. To give the Mark II additional power, ADA plans to replace the Mark I’s General Electric F-404 engine, which develops barely 80 KiloNewtons of thrust, with a more recent General Electric F-414 engine that will provide 90-96 KiloNewtons. But an internal ADA study has found that there may eventually be no benefit from this upgrade, since the Tejas’ fuselage would have to be significantly redesigned to accommodate the bulkier, heavier F-414. All this added weight, the study concludes, would neutralize the new engine’s added power. Furthermore, there is a longstanding design flaw in the Tejas air intake, which allows barely enough air to be sucked in for the current F-404 engine. Fitting the more powerful F-414 would require the air intakes to be enlarged as well. And the rearrangement of so many major aerostructures would shift the Mark II’s centre of gravity, necessitating the shifting around of other components to get the balance right.

Instead of this major redesign, loaded with the likelihood of further delays, it would be far more prudent to order more Tejas Mark I, while restricting the scope of the Mark II upgrade. This is where the third major benefit would come in --- through the early activation of a mass production line on which Hindustan Aeronautics Ltd (HAL) could build fighters quickly. Currently, the tiny volume of orders (20 Mark I ordered, 20 more in the pipeline) prevents HAL from ramping up its supply chains and investing in an assembly line that can churn out at least ten fighters a year. So slow is the current process that HAL will deliver the first Tejas Mark I in mid-2014; the second in late-2014; and just three Tejas in 2015.

Given the need to replace the MiG-21 quickly, as also the need to indigenize our arsenal, this is appallingly slow. Defence Minister AK Antony, at the annual Tejas Review Meeting on Jun 24, promised HAL Rs 1,500 crore for setting up the Tejas assembly line. But that is missing the wood for the trees; what use is an assembly line in the absence of orders?

What is needed then is an immediate IAF order for at least three squadrons [Maybe he meant 3 in addition to 2 already ordered? Otherwise its just one extra squad from existing plans.] of Tejas Mark I, which would galvanize HAL and the supply chains into activity. While releasing Rs 1,500 crore to HAL, instructions must be issued that the production line must deliver six Tejas Mark I fighters in 2014, and hit its production target of ten fighters per year in 2015. Meanwhile the Tejas Mark II must be fully developed by 2016. This would require it to be less ambitious, restricting itself to modernizing avionics; fitting an Active Electronically Scanned Array (AESA) radar; mounting more advanced air-to-air missiles; developing an onboard oxygen-generating system; and equipping the fighter with a mid-air refuelling system to increase its range.

vishvak · Post by **vishvak** » 23 Jul 2013 10:40

ramana wrote:
quote="Manish_Sharma"]Just before Rafale was chosen, US forbade israel to sell 2052 to Hindusthanam!

http://gfilesindia.com/frmArticleDetail ... ER%20STORY
...
::quote]

They did the same withthe cryogenic engine. General Dynamics wanted to seel just the engines whiel India wanted the technology. So Russians had an engine which needed development. After India signed with the Russians, the US invoked MTCR sanctions etc on Russia to prevent the sale. And gave them some token satellite launhes as baksheesh.

And even claimed ISRO scientists were quitting and joining DRDO. So UR Rao told Al Gore what about the many Indians who quit ISRO and joined NASA! Why not put sanctions on NASA.

Massan sanctions regime in its full radiation. While Massa doesn't mind throwing monies and hardware to its partner baki terrorists, a direct sale or even joint development with Russia is held hostage to Massan sanctions regime. Silence on black market of nukes is another indicator of sanctions duplicity.

This is a clear example of disadvantag. Double speaking massan with sanction regime of offers only retards growth even indirectly on one hand and offers are deliberately lesser than the best. On the other hand periodic exceptions to own sanctions on partner baki terrorists by Massa is not hidden.

member_22019 · Post by **member_22019** » 23 Jul 2013 11:00

...But an internal ADA study has found that there may eventually be no benefit from this upgrade, since the Tejas’ fuselage would have to be significantly redesigned to accommodate the bulkier, heavier F-414. All this added weight, the study concludes, would neutralize the new engine’s added power...

This is a surprise for me. I don't remember if this had been discussed in the forum. If F-414 does not add any extra power then why would it be considered by agencies for MK-II at all.

Sanku · Post by **Sanku** » 23 Jul 2013 11:46

Is F-414 a done deal for Mk II ? A Kaveri Upgd is not in the pipeline at all?

member_20317 · Post by **member_20317** » 23 Jul 2013 13:14

If used in LCA what effect will AAMs placed that way have on WVR dogfights e.g. on frontal RCS and aerodynamics?

Would it be debilitating?

What if we use this arrangement for the BVR missiles but not for the WVR missiles. Separating the racks just before the LCA enters a dogfight?

nachiket · Post by **nachiket** » 23 Jul 2013 13:28

Sanku wrote:Is F-414 a done deal for Mk II ? A Kaveri Upgd is not in the pipeline at all?

The deal has already been signed for 99 F414s IIRC. I doubt the LCA will ever fly in service with any version of the Kaveri. But the Kaveri is important for the AMCA. The GTRE has more time on their hands to develop the Kaveri now. Hope they use it wisely. They should beg, borrow, steal whatever unavailable technologies that are currently causing bottlenecks in development. Kaveri needs to be developed on a war footing. But not for the LCA.

vishvak · Post by **vishvak** » 23 Jul 2013 13:37

SiddharthS wrote:
...But an internal ADA study has found that there may eventually be no benefit from this upgrade, since the Tejas’ fuselage would have to be significantly redesigned to accommodate the bulkier, heavier F-414. All this added weight, the study concludes, would neutralize the new engine’s added power...
This is a surprise for me. I don't remember if this had been discussed in the forum. If F-414 does not add any extra power then why would it be considered by agencies for MK-II at all.

If all this has to be done again why not with our own engine. Make it 1x Kaveri x2 for need of more power and change profile of Tejas 1 to purely point defense - for change in minimum take off weight. Profile change doesn't necessarily mean change in capability but while Kaveri arrives this can be one optional arrangement. Bankrolling US engines when it makes no difference on delivery improvement or even delay makes sense?

karadi · Post by **karadi** » 23 Jul 2013 15:54

Hey. Sorry bit off topic.

About 2 weeks back I saw the LCA fly over my home in Bangalore.
It came in a flash and then just zoomed away into the clouds.

It was a beautiful site.

kaRadi

Philip · Post by **Philip** » 23 Jul 2013 18:38

It's what many of us have been saying for years,induct MK-1 as soon as possible in a purely air defence role so that the bird can be evaluated and refined.However,I don't see why the LCA's development has to end with just MK-1.Here I disagree with the esteemed officer.There is no harm in developing a MK-2 with a more powerful engine,in fact the EJ-TVC engine would've been a good alternative,as in any case the NLCA will require more power for carrier ops,as its range is poor in comparison with the MIG-29K.In any aircraft project,further avatars with upgrades are systematically conducted so that the aircraft remains relevant as the years go by.How else could we have had the MIG-21 serve us for 50 years+? The ACM at a function to mark the event spoke in glowing terms of the aircraft and how an entire generation of pilots cut their teeth on it.The LCA should be the light,low cost affordable desi fighter which in the Paki context can keep the numbers of the IAF healthy.If the IAF is satisfied with the MK-1,I'm sure that in a short time of operations,they will order more.In any case current production figures are a mere 8 per year (can be scaled up to 12).How can we induct hundreds of LCAs at such a slow rate? Where will the IAF get its aircraft for the next 5-7 crucial years when the Chinese see a window of opportunity to launch a surprise attack and chew off a critical piece of Indian territory? Even the establishment of the 40,000+ str0ng mountain corps/divisions is not going to happen overnight.

SaiK · Post by **SaiK** » 23 Jul 2013 19:11

SiddharthS wrote:
...But an internal ADA study has found that there may eventually be no benefit from this upgrade, since the Tejas’ fuselage would have to be significantly redesigned to accommodate the bulkier, heavier F-414. All this added weight, the study concludes, would neutralize the new engine’s added power...
This is a surprise for me. I don't remember if this had been discussed in the forum. If F-414 does not add any extra power then why would it be considered by agencies for MK-II at all.

boss, tell me if 1,036 kg 404 upgrade to 1,110 kg 414 is a big weight addition for a core need, and that provides the additional thrusts. why not just look at it from t:w? something is not right in those design thoughts.

NRao · Post by **NRao** » 23 Jul 2013 20:04

1,036 kg 404 upgrade to 1,110 kg 414

Assume you are referring to the weight of the two engines. The article is referring to the weight associated with the modifications that were necessary to accommodate the new 414.

SS, I agree, this is the first time I am hearing about the ADA study.

However, I was under the impression that the additional thrust was requested by the Indian Navy for their naval LCA and that the IAF went along for the ride. IIRC Kartik's post was clear about that (and the only reference that I know of too). So, by simple logic, the IAF should have been happy with the Mk-I - the IAF did not NEED a 414.

On the topic of Mk-I for the IAF, the issue is related to acceptance. Like Sarkar stated, the IAF needs to induct the LCA - as is - and fly it with limitations just like they do with the MiG-21.

SaiK · Post by **SaiK** » 23 Jul 2013 23:28

The problem there is the developer and user must have an agreement of minimum purchase quantity per block. At the very least, they should develop a model for the future from LCA-2 onwards. Get it on paper that the user will have to buy x number of jets per block change request.

Sancho · Post by **Sancho** » 24 Jul 2013 07:25

Philip wrote:Is it -the 2052 available? I thought that there was some hesitation some time ago about giving us the details/TOT for the same. It would make sense at least for the MK-2,or the follow on 20 of the first batch of 40MK-1s on order. Apart from the Jaguars,why not even use it on the Sea Harriers too,which have operational life in them for another decade at least.

It's not as already shown. It was rejected by the US during MMRCA for the Gripen was rejected for LCA as well. It is even questionable if the Israelis can upgrade their F16s with it, since the Americans will insist on US AESA's again.

From what is reported, the indigenous puls doppple MMR doesn't seems to be ready yet, which is why MK1 will get the EM 2032's. The simple fact that the indigenous MMR can't even be used for the limited capable Jags and again the Israeli MMR needs to be procured tells us something about our status in the fighter radar field.

ADA officials even stated, that the early LCA MK2s might use the indigenous puls doppler MMR and later versions + upgraded MK1s should get the indigenous AESA, but when we can't develop a decent puls doppler radar for the Jags and LCA MK1, how realistic is an AESA anytime soon?
The whole "hoping" on DRDO in the radar and engine fields were the main mistakes of the LCA project and if we continue only with hope, even more delays and problems are likely.

Btw, why would you want to waste money for an AESA on Jags (without credible A2A capability), or a dozen of Harriers, that hardly will play a role anymore as soon as the Mig 29Ks will have a carrier to operate from?
We produced the Jags till 2008 and the last one will have a life to be operated till 2038 or longer, but that doesn't mean they will have any operational meaning even till the end of this decade, don't you think?

Kartik · Post by **Kartik** » 24 Jul 2013 09:50

NRao wrote:
1,036 kg 404 upgrade to 1,110 kg 414
Assume you are referring to the weight of the two engines. The article is referring to the weight associated with the modifications that were necessary to accommodate the new 414.

SS, I agree, this is the first time I am hearing about the ADA study.

However, I was under the impression that the additional thrust was requested by the Indian Navy for their naval LCA and that the IAF went along for the ride. IIRC Kartik's post was clear about that (and the only reference that I know of too). So, by simple logic, the IAF should have been happy with the Mk-I - the IAF did not NEED a 414.

On the topic of Mk-I for the IAF, the issue is related to acceptance. Like Sarkar stated, the IAF needs to induct the LCA - as is - and fly it with limitations just like they do with the MiG-21.

Yes, that was indeed what I was told by Cmde Sukesh Nagaraj. I've never heard of such an ADA study either, and I'd be a little cautious when reading such reports by Ajai Shukla..while he's better than some others, he's not always right either..for instance, when I asked Cmde Maolankar about the engine air-starvation at higher alpha issue (which Ajai Shukla had earlier claimed was preventing the LCA from going to higher than 22 deg alpha), Cmde Mao just dismissed that as being not true. Ajai reiterates that same thing in this new article as well, so I'm not sure what his sources are..

There was some report that the LCA has now met the STR requirements in the ASR, a key requirement before IOC-II. So it does appear that the Tejas Mk1 is now able to meet most of the performance requirements in the ASR..except for being 9G capable. That will come with the Tejas Mk2.

Philip · Post by **Philip** » 24 Jul 2013 11:13

Some good news.

Media reports (Ind.Exp.) that the GOI /MOD is "happy" with progress on the aircraft being developed,LCA and IJT,notwithstanding the 3 decade time taken.The MoS DM speaking to reporters said that good progress had been made in the last 6 months after the IAF had hauled up HAL and the ADA for the delays.Issues regarding "wheels and overheating of brakes" had been rectified.IOC now expected Nov-2013 and FOC-Dec. 2014. The Minister said that the IOC for the IJT may be delayed by a "month or two".On FGFA cost escalation,he said that it was because of the rupee's fall,"which will have a repercussion on imports".Jitendra Singh also said that the "much delayed "HTT-40 could be used for other purposes for "Coast Guard operations and also by Police forces" (!).

The IAF is known not to want the HTT at any cost (which is costlier than the Pilatus),so are we really going to see the CG or Police accept it?

nash · Post by **nash** » 24 Jul 2013 11:40

we should think relatively on GE-414 in LCA, it gives around 20% more thrust than 404, so in that way if weight of LCA-MkII increases up to 7000-7500Kg from current 6500, it would still give some extra to LCA. Only speculation here is how much weight of LCA will increase with 414.

SaiK · Post by **SaiK** » 25 Jul 2013 01:28

would the engine air-starvation at high alpha or turns be due to the dynamicity of the airflow vanes? something that is blocking due to the angle of attack!? meaning they are not operating/be controlled at the right ms/ns timeframe? /assuming there is a control to keep either bypass/flow ratio different at different altitude because of different O2 levels/pressure points.

question onlee

astal · Post by **astal** » 25 Jul 2013 02:21

Kartik, Phillip,

If STR issue has been solved, the only know open issues are materials for radar nose cone and radar performance right?

member_22539 · Post by **member_22539** » 25 Jul 2013 08:48

Philip wrote:Some good news.

Media reports (Ind.Exp.) that the GOI /MOD is "happy" with progress on the aircraft being developed,LCA and IJT,notwithstanding the 3 decade time taken.The MoS DM speaking to reporters said that good progress had been made in the last 6 months after the IAF had hauled up HAL and the ADA for the delays.Issues regarding "wheels and overheating of brakes" had been rectified.IOC now expected Nov-2013 and FOC-Dec. 2014. The Minister said that the IOC for the IJT may be delayed by a "month or two".On FGFA cost escalation,he said that it was because of the rupee's fall,"which will have a repercussion on imports".Jitendra Singh also said that the "much delayed "HTT-40 could be used for other purposes for "Coast Guard operations and also by Police forces" (!).

The IAF is known not to want the HTT at any cost (which is costlier than the Pilatus),so are we really going to see the CG or Police accept it?

LCA did not take 3 decades to make and HTT-40 will not be costlier than pilatus. I know your are not ignorant of these facts and that it has been argued ad nauseam, which leads me to guess that either you have selective amnesia or you are misinforming. Which is it?

Kartik · Post by **Kartik** » 25 Jul 2013 09:12

astal wrote:Kartik, Phillip,

If STR issue has been solved, the only know open issues are materials for radar nose cone and radar performance right?

Perhaps wake penetration tests as well..

astal · Post by **astal** » 25 Jul 2013 11:28

Kartik wrote:
Perhaps wake penetration tests as well..

Thanks. Hope they go well too.

Lalmohan · Post by **Lalmohan** » 25 Jul 2013 12:14

saik - air intake variable geometry is usually done to manage the onset of the shock wave during transonic flight regimes; think of the air intake like a tube you are blowing into, as alpha changes, the air flow into it will also change, eventually stalling. changing the air intake geometry to adjust for alpha is feasible (IIRC the F14 had something like this for low speed flight regimes - but this might be musharraf-talk) but normally the advantages are lost due to the additional weight and control system complexity. i also suspect that before you stall the airflow into the air intake, the wing will be well and truly stalled, making the whole thing moot

merlin · Post by **merlin** » 25 Jul 2013 12:25

Kartik wrote:
astal wrote:Kartik, Phillip,

If STR issue has been solved, the only know open issues are materials for radar nose cone and radar performance right?
Perhaps wake penetration tests as well..

And lightning protection tests, though I seem to recall reading its been moved to FOC.

geeth · Post by **geeth** » 25 Jul 2013 13:23

To cater for AoA, air intakes are raked - eg., f15, mig 23,27,29 etc. LCA does not have raked intake, so more susceptible to AoA problems. Variable Geo/adjustible air intakes are more for managing the shock waves at different Mach

geeth · Post by **geeth** » 25 Jul 2013 13:24

To cater for AoA, air intakes are raked - eg., f15, mig 23,27,29 etc. LCA does not have raked intake, so more susceptible to AoA problems. Variable Geo/adjustible air intakes are more for managing the shock waves at different Mach

vina · Post by **vina** » 25 Jul 2013 13:59

geeth wrote:To cater for AoA, air intakes are raked - eg., f15, mig 23,27,29 etc. LCA does not have raked intake, so more susceptible to AoA problems. Variable Geo/adjustible air intakes are more for managing the shock waves at different Mach

Ayyo!! . You should pay careful attention to LalMullah, especially when he posts here and and not in the L&M thread about Lycreshwaris.

The YellCeeYea has a wing shielded inlet , the others have the inlet in the free stream. That is a big difference, and helps do away with variable geometry inlet and a simple fixed inlet will suffice. And any AoA and other stuff like surge ,buzz and separation are done away with as well , and any limits to that like AOA is more relevant to the wing (as it will happen first there) before the inlet

vic · Post by **vic** » 25 Jul 2013 19:03

A Question to Gurus:-

Does the wing twist on LCA adds to drag?