Bharat Rakshak

Consortium of Indian Defence Websites
It is currently 21 Dec 2014 16:54

All times are UTC + 5:30 hours




Post new topic This topic is locked, you cannot edit posts or make further replies.  [ 4018 posts ]  Go to page Previous  1 ... 73, 74, 75, 76, 77, 78, 79 ... 101  Next
Author Message
PostPosted: 13 Feb 2012 17:50 
Offline
BRFite

Joined: 29 Nov 2011 00:42
Posts: 194
Cain Marko wrote:
^^ What I don't get is why they keep going to the US time after time, jhatka after chatka! That too for a program that so critical to self sufficiency. Its like the LCA decisionmakers have some serious victim mentality/addiction and can't get out of an abusive relationship.


Correct.

Why not French/Russian engines?

I know it is too late now as the deal with GE signed.

PS: Ultimately we need to develop our own engines - Kaveri Zindabad!


Top
 Profile  
 
PostPosted: 13 Feb 2012 23:07 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
Flight test update

LCA-Tejas has completed 1777 Test Flights successfully. (10-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-44,LSP5-64)

from

LCA-Tejas has completed 1776 Test Flights successfully. (08-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-44,LSP5-63)


Top
 Profile  
 
PostPosted: 14 Feb 2012 03:30 
Offline
BRFite -Trainee

Joined: 05 Feb 2012 00:45
Posts: 7
Few questions regarding GE 404 engines for LCA Mk1:-
1.When did GE deliver all 40 engines.
2.What is the long term storage procedure for such military power packs.
3.Considering 11 ready aircraft and LSP 7 & 8 , there will be around 27 engines still in some ware house, how does HAL fair in critical systems storage.
4.Does long shelf life reduces engine life (for eg. Turbine Blades, Power Unit and Electronics).
5.Is GE support required for start up & integration of engine with airframe

My point is can long terms storage cause any hiccups during operation service, for example in normal production air frame and powerpack will be around same age :roll:


Top
 Profile  
 
PostPosted: 14 Feb 2012 08:55 
Offline
BRF Oldie

Joined: 29 Oct 2003 12:31
Posts: 26843
Location: NowHere
the reason I bayed blood for ge, when ej-200s were introduced.. sometimes, politics and strategy does not go along with l1 and l2 business setups... very bad decision later on.. with having nothing gained. wtf agreements with unkil against using weapons on pakistan is in itself a pathetic understanding of strategic relationships. it is the fault of GoI/MoD. I hope GoI just don't keep quite, and ensure such stupidity is not uttered by nation on the planet. boot them out before they even think about talking business.

btw:
Quote:
Responding to questions, Saraswat said the naval version of the Light Combat Aircraft should take to the skies on its maiden flight in a month's time. "Already, taxiing trials are underway.

There are differences between the naval and air force versions of the LCA. So, before going to the flight, we have to ensure that those differences (systems, equipment) are working. So we are now testing all the different systems," he said.


Top
 Profile  
 
PostPosted: 15 Feb 2012 09:04 
Offline
BRFite

Joined: 04 Jul 1999 11:31
Posts: 421
With the N-LCA plane, have they redesign the air intakes as to increase the efficiency of thrust. On another forum, somebody says that the main flaw of LCA was its air intake design. He alleged that It is not getting enough thrust despite the Gripen using the same engine getting more thrust even though it is heavier than the the LCA and getting a better flight performance profile.

If the DRDO wants to overcome the flaw, it must come with a more powerful engine or redesign the airflow intakes which will push back the program another 3-5 years. If that's the case, why not do the most obvious thing? Use the N-LCA programme as a cover to redesign the air intake flow and after the N-LCA flies, use the redesigned N-LCA as LCA mk. 2. Problem solved. In the intervening years of 3-5 years, HAL can produce the 40 Tejas and improve the avionics and other parts of the plane as a parallel development course while the N-LCA gets the air intake flow design flaw fixed.


Top
 Profile  
 
PostPosted: 15 Feb 2012 09:50 
Offline
Forum Moderator

Joined: 13 Aug 2004 19:42
Posts: 34017
Location: Col of the regiment, ORR JTF unit
dont know about the air intakes, but the gripen is apparently also a less draggy design and the Tejas is more stubby than needed. so in Mk2 they were planning to make the fuselage 1m longer to give it a more tapering less draggy shape...nose section and aft section of cockpit will be stretched to accomodate more avionic and perhaps a bigger radar area (for aesa radar). height would increase by 20cm due to bigger vertical tail but same wingspan with some increased wing area.

the airflow of original mk1 was definitely less than needed. they tried to mitigate it to extent possible without airframe redesign but using those jaguar style side air intakes that are spring loaded and deploy as needed.

and one of core deficiencies in Mk1 is the lack of a IFR probe...that will be fixed.


Top
 Profile  
 
PostPosted: 15 Feb 2012 10:03 
Offline
BRFite

Joined: 04 Jul 1999 11:31
Posts: 421
What is spring loaded and what are LEXCONs? I tried looking at the pictures of LCA and N-LCAs and cannot figure out what are LEVCONs or LEXCONS whatever they are called. I am not an aeronautical engineer, just a layman. If possible, is there a picture with a diagram that shows exactly where the LEXCONs are so I can easily identify them?


Top
 Profile  
 
PostPosted: 15 Feb 2012 10:11 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
No news on the horizon, hope they dont wait until monsoons in blore :(( and blame the monsoons for the delay


Top
 Profile  
 
PostPosted: 15 Feb 2012 10:14 
Offline
Forum Moderator

Joined: 13 Aug 2004 19:42
Posts: 34017
Location: Col of the regiment, ORR JTF unit
http://2.bp.blogspot.com/_zUe7sq7m3h0/T ... /LCA+(Navy)+rolling+out+(6).jpg

in this pic, that small canard type thing where the leading edge of wing joins fuselage is moveable. I believe at high AoA it will bend down and redirect more air into the engine intakes (?) the PAKFA has it too. those are the levcons.

http://www.bharat-rakshak.com/IAF/Image ... 03-Mar.jpg

in this pic look for the small vertical slit type intake a couple feet behind the main intake on the side. it a door that can open and close when the engine needs more air.

the Jags have two on each side
http://farm3.static.flickr.com/2278/236 ... f16c54.jpg


Top
 Profile  
 
PostPosted: 15 Feb 2012 10:42 
Offline
BRF Oldie

Joined: 29 Oct 2003 12:31
Posts: 26843
Location: NowHere
At higher AoA, the lift is increased while the trailing edge ailerons provides the drag, iirc... that is when the levcon is facing at 0 angle [zero to flow direction] compared AoA [correction needed].. so, the stabilized lift/control can be given. without which or without canards, it would be difficult to reach higher AoA without perhaps a TVC.

so it helps, especially for landing on the carrier, with an extra AoA, and higher stability of flow control as the levcon redirects and provides the additional lift, and without which a potential stall can happen. Also, at higher AoA, it is easier for the arresters to latch on, or if it fails, a few more wet thrust is all needed to continue ahead for a second landing.

sometime back, some guru explained it more clearer here.


Top
 Profile  
 
PostPosted: 15 Feb 2012 13:48 
Offline
BRFite

Joined: 21 Jan 2012 21:18
Posts: 122
Tejas models at Singapore.


http://2.bp.blogspot.com/-aNGaW3rtjZQ/T ... +Booth.jpg


Top
 Profile  
 
PostPosted: 15 Feb 2012 17:55 
Offline
BRF Oldie

Joined: 01 Jan 1970 05:30
Posts: 11356
Location: India
I am serious! Tejas at Singapore has tremednous export potential,in model form.There are zillions of aircraft enthusiasts around the globe who collect aircraft models amd collecting an authentic numbered Tejas models,"signed" by HAL,would become collector's items.The same can be mass produced in plastic/composites for the mases,"Airfix" style kits too.I'm sure that Hamley's would be interested as one sees so many Yindian shoppers in its flagship London establishment.I"m sure this can help cut down the hotel/travel bills for HAL's worthies, and the cost of the stall at the Sing air show!

As they say one must first walk before we can run.Let's export Tejas models first and then the bird when it evetually arrives!


Top
 Profile  
 
PostPosted: 16 Feb 2012 02:35 
Offline
BRFite

Joined: 06 Mar 2001 12:31
Posts: 220
Location: Niyar kampootar onlee
indranilroy wrote:
Raghu,

I had a long pending question about the LCA. I would be very grateful if you or your ex-roommate could answer it. Obviously avoid replying if the answer is classified in any manner.

Observation:
While there is beautiful blending of the wing with the fuselage on the upper side, the lower side of the wing is completely at right angles to the body. The MK II models displayed at AI-11 did not show any lower-wing-body blending.

The advantages of the wing body blending with respect to lower drag and RCS is well known. Also the wing body blending should provide space for the main landing gear and hence free up more internal space.

Question:
Is the lower wing body blending being avoided in order to stick to timelines or is there some aerodynamic/structural reason(s)?


indranilroy,

First, In all wings, flow over the upper surface is much more critical than the lower surface. This is the reason why you can suspend pylons, weapons, fuel tanks, engine mounts, etc. on the bottom of the wings and yet not affect the essential lift capability of the wing. The wing-body blending on the upper surface essentially creates a larger upper wing surface for lift to act. This is not critical on the lower surface.

Second, while blending in the lower surface may marginally reduce interference drag it will either (a) increase the cross-sectional area in the fuselage section where cross sectional area is very critical (i.e., wing-fuselage junction) thereby increasing wave drag and hampering trans/supersonic performance, or (b) if the fuselage is tapered to maintain the same cross sectional area, reduce the volume available in the fuselage, which is a critical commodity in a small aircraft.

My guess is that the designers concluded that the tradeoff wasn't worth it.


Top
 Profile  
 
PostPosted: 16 Feb 2012 04:28 
Offline
Forum Moderator

Joined: 02 Apr 2010 01:21
Posts: 3105
I like your answer :). My answers inline (in blue).
Raman wrote:
indranilroy wrote:
Raghu,

I had a long pending question about the LCA. I would be very grateful if you or your ex-roommate could answer it. Obviously avoid replying if the answer is classified in any manner.

Observation:
While there is beautiful blending of the wing with the fuselage on the upper side, the lower side of the wing is completely at right angles to the body. The MK II models displayed at AI-11 did not show any lower-wing-body blending.

The advantages of the wing body blending with respect to lower drag and RCS is well known. Also the wing body blending should provide space for the main landing gear and hence free up more internal space.

Question:
Is the lower wing body blending being avoided in order to stick to timelines or is there some aerodynamic/structural reason(s)?


indranilroy,

First, In all wings, flow over the upper surface is much more critical than the lower surface. This is the reason why you can suspend pylons, weapons, fuel tanks, engine mounts, etc. on the bottom of the wings and yet not affect the essential lift capability of the wing. The wing-body blending on the upper surface essentially creates a larger upper wing surface for lift to act. This is not critical on the lower surface.
This is beyond the point. On the question of lift coefficient of the wing, I can simply ask the question. Does adding a smoothening adversely affect lift coefficient? For most aircrafts it doesn't. However for LCA it is interesting as the wing root itself has a huge twist. after making this observation, one might say, why not a symmetrically twisted smoothening?


Second, while blending in the lower surface may marginally reduce interference drag it will either (a) increase the cross-sectional area in the fuselage section where cross sectional area is very critical (i.e., wing-fuselage junction) thereby increasing wave drag and hampering trans/supersonic performance, or (b) if the fuselage is tapered to maintain the same cross sectional area, reduce the volume available in the fuselage, which is a critical commodity in a small aircraft.

My guess is that the designers concluded that the tradeoff wasn't worth it.
You mean that the critical mach number for the plane would be lowered. But by how much? The wing body blend is essentially very smooth! By carefully choosing the wing body blend one could maintain a very smooth curve for the area curve, thus minimizing wave drag. There is no need of narrowing the fuselage. I had seen area curve of LCA, it is very smooth along the chord of the wing. There are steep rises before the wing and after the wing, which they are working on smoothening.

Also correct me if I am wrong here. the tradeoff between interference drag and wave drag has been well settled in favour of having a blended wing? This is the basis of the all blended wing designs from the Junkers G.38 to the X-48 and Be-2500 etc. and fourth generation planes except EF



Anyways, it is nice discussion. As an aerodynamics enthusiast, I would love to know why certain choices were made. Probably that would not happen in public space. Will have to befriend some LCA guys or get employed there! Problem is why would they hire me :|


Top
 Profile  
 
PostPosted: 16 Feb 2012 23:08 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
Flight test update

LCA-Tejas has completed 1778 Test Flights successfully. (14-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-44,LSP5-65)

from

LCA-Tejas has completed 1777 Test Flights successfully. (10-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-44,LSP5-64)


Top
 Profile  
 
PostPosted: 17 Feb 2012 00:38 
Offline
BRFite

Joined: 06 Mar 2001 12:31
Posts: 220
Location: Niyar kampootar onlee
indranilroy,

Quote:
Does adding a smoothening adversely affect lift coefficient? For most aircrafts it doesn't. However for LCA it is interesting as the wing root itself has a huge twist. after making this observation, one might say, why not a symmetrically twisted smoothening?


I think you are talking about different things in the same breath.

First: Does "smoothening" the lower surface affect lift coefficient? Yes, anything that affects the airfoil profile will affect the lift coefficient. Second: Does it *adversely* affect lift coefficient? Probably. You are essentially tending towards a symmetric airfoil, which have lower lift coefficients than cambered airfoils for a given angle-of-attack.
Third: LCA wing has a huge "twist" at the root. Yes. This is for two reasons: first to ensure that the entire wing doesn't stall at once. Second, a lot of that "twist" at the root is to control the oblique shocks for the inlet to operate at supersonic speeds.

The issue I was trying to highlight in my first statement is that there are good reasons to wing-body blend the upper surface; not so for the lower surface.

Quote:
You mean that the critical mach number for the plane would be lowered. But by how much? The wing body blend is essentially very smooth! By carefully choosing the wing body blend one could maintain a very smooth curve for the area curve, thus minimizing wave drag. There is no need of narrowing the fuselage. I had seen area curve of LCA, it is very smooth along the chord of the wing. There are steep rises before the wing and after the wing, which they are working on smoothening.

Also correct me if I am wrong here. the tradeoff between interference drag and wave drag has been well settled in favour of having a blended wing? This is the basis of the all blended wing designs from the Junkers G.38 to the X-48 and Be-2500 etc. and fourth generation planes except EF


I was not referring to critical mach at all. The point is blending the lower surface will increase the cross sectional area of the airplane. Increasing/decreasing the cross sectional area smoothly is not enough. I think this is the point you are missing. The CS area distribution must match the Sears-Haack distribution closely to minimize wave drag. Just blending without paying attention to the Sears-Haack distribution will increase wave drag unless the fuselage volume is correspondingly reduced, which we cannot do for reasons of packaging/estate management.


Top
 Profile  
 
PostPosted: 17 Feb 2012 03:28 
Offline
Forum Moderator

Joined: 02 Apr 2010 01:21
Posts: 3105
Raman sir, probably you are right!

You are right ... if we have to retain the sharp edge of the leading edge of the wing and trailing edge of the supersonic wing, then the smoothening will be a bulge and that will lower the camber and hence the CL. That is a good point.

I remember the wonderful discussion of the LCA wing a couple of years back. So I do understand the basics and reasons behinds its shape. I was very interested to know ... I thought some of the posts there should have been made sticky :D.

Coming now to the tradeoff between the wave drag and the interference drag. I will try to dig up the area curve of LCA Tejas (Kartik could you help me find the pdf which discussed the planned refinements in LCA) ... may be we can do some back of the envelop calculations for increase in wave drag ... Alas we can't do anything to find the approximate decrease in interference drag.

Once again it was a good discussion for me :)


Top
 Profile  
 
PostPosted: 17 Feb 2012 04:03 
Offline
Forum Moderator

Joined: 02 Apr 2010 01:21
Posts: 3105
Okay found the paper which had the area curve: http://www.drdo.gov.in/drdo/pub/dss/200 ... EMILAC.pdf (pg. 9).

Question is whether it is acceptable to increase the area between stations 6 to 11 or so?

Most probably they would have done CFD analysis and found that it is not! Ah, but the itch to know ...


Top
 Profile  
 
PostPosted: 17 Feb 2012 10:20 
Offline
BRFite -Trainee

Joined: 16 Feb 2012 18:40
Posts: 6
Hi All,
This is my first post although I have been lurking on BR for almost 11 years.
Am SDRE IT guy from Bangalore.

Yesterday around 2 pm show LCA with IFR probe. Are there any of them LSP or PV flying with IFR attached? Or was it LSP 6/7


Top
 Profile  
 
PostPosted: 17 Feb 2012 10:28 
Offline
BRF Oldie

Joined: 05 Apr 2006 16:25
Posts: 7100
Flight Test News


LCA-Tejas has completed 1779 Test Flights successfully. (16-Feb-2012).

(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-45,LSP5-65)


LCA-Tejas has completed 1778 Test Flights successfully. (14-Feb-2012).

(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-44,LSP5-65)

Based on ADA website no LSP6/7 in the Air, only 1 flight in the last 2 days.


Last edited by Aditya_V on 17 Feb 2012 11:26, edited 1 time in total.

Top
 Profile  
 
PostPosted: 17 Feb 2012 11:24 
Offline
BRF Oldie

Joined: 05 Apr 2006 16:25
Posts: 7100
Ok, Sorry copy posted from ADA website. Corrected my post, continuing from Suryag's post


Top
 Profile  
 
PostPosted: 18 Feb 2012 02:05 
Offline
BRFite

Joined: 26 Jun 2005 10:26
Posts: 1420
Location: Atop Orthanc, cursing, "Damn it where are those backfires??"
ketan.sojitra wrote:
Hi All,
This is my first post although I have been lurking on BR for almost 11 years.
Am SDRE IT guy from Bangalore.

Yesterday around 2 pm show LCA with IFR probe. Are there any of them LSP or PV flying with IFR attached? Or was it LSP 6/7


Very, very interesting Ketan, welcome to the board - you come bearing good/interesting news. Can any jingos with inside clearances to sensitive areas such as golf courses or roof tops confirm this development?

CM


Top
 Profile  
 
PostPosted: 18 Feb 2012 02:41 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
[wetdreams] was it PV2?, it seems to have flown after a long time (after two months)[/wetdreams]


Top
 Profile  
 
PostPosted: 18 Feb 2012 02:48 
Offline
BRF Oldie

Joined: 02 Dec 2008 10:49
Posts: 5046
ketan.sojitra wrote:
Yesterday around 2 pm show LCA with IFR probe. Are there any of them LSP or PV flying with IFR attached? Or was it LSP 6/7

Are you sure it was an LCA? Some fighter jets are difficult to distinguish from afar. A M2000 for e.g. can easily be confused with an LCA if you catch only a quick glimpse or if it's too far away. A M2000 would be a rare sight in BLR though.


Top
 Profile  
 
PostPosted: 18 Feb 2012 08:31 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
SBTF update from tarmak

Quote:
While the SBTF work is probably ahead of the schedule, sources say that the eagerly-awaited first flight of NLCA (Naval Prototype NP-1) is on course. The platform is said to have undergone a trial for nose-wheel checks (70 km) on Valentine’s Day, while a LSTT (low-speed taxi trial) at a possible max speed of 140 km/hour is scheduled for February 18. This would be followed by a HSTT (high-speed taxi trial) at a maximum speed of 200-200 km/hour and then the subsequent first flight.


Top
 Profile  
 
PostPosted: 18 Feb 2012 09:06 
Offline
Forum Moderator

Joined: 13 Aug 2004 19:42
Posts: 34017
Location: Col of the regiment, ORR JTF unit
in 7 yrs the only time I have never seen M2K in HAL. did see MKI few times flying into HAL for events like AI09.


Top
 Profile  
 
PostPosted: 18 Feb 2012 10:31 
Offline
BRF Oldie

Joined: 01 Jan 1970 05:30
Posts: 2155
Location: NullPointerException
So lets see what is the sequence of events for an LCA new bird to fly

1. Fabrication
2. Roll out
3. SCT, vibration and other tests
4. Engine Ground Run (EGR)
5. Nose wheel checks (at 70 kmph per above report)
6. Low speed taxi trials (at 140 kmph per above report)
7. High speed taxi trials (at 200-220 kmph per above report)
8. Rotation tests?
9. First flight


Top
 Profile  
 
PostPosted: 18 Feb 2012 10:44 
Offline
BRFite

Joined: 01 Jan 1970 05:30
Posts: 312
Singha wrote:
in 7 yrs the only time I have never seen M2K in HAL............


"They" don't fly, they are for some sort of "research purposes" onlee.


Top
 Profile  
 
PostPosted: 18 Feb 2012 12:59 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
Flight test update

LCA-Tejas has completed 1780 Test Flights successfully. (17-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-68,LSP2-198,PV5-36,LSP3-46,LSP4-45,LSP5-65)

from

LCA-Tejas has completed 1779 Test Flights successfully. (16-Feb-2012).
(TD1-233,TD2-305,PV1-242,PV2-212,PV3-330,LSP1-67,LSP2-198,PV5-36,LSP3-46,LSP4-45,LSP5-65)

Someday i would like to know what group of aircraft was used for what kind of flight testing


Top
 Profile  
 
PostPosted: 18 Feb 2012 14:44 
Offline
BRFite -Trainee

Joined: 12 May 2010 02:23
Posts: 74
So Boeing is planning to make about 10 Dreamliners a month by Q4 2013, scaling up from its current 2.5 a month . Meanwhile, HAL is going to make about 10 a year ramping up from Zero all of last year.... just saying.

http://online.wsj.com/article/BT-CO-201 ... 01263.html


Top
 Profile  
 
PostPosted: 18 Feb 2012 14:54 
Offline
BRFite

Joined: 12 Jun 2010 23:06
Posts: 249
Location: look behind you
Quote:
So Boeing is planning to make about 10 Dreamliners a month by Q4 2013, scaling up from its current 2.5 a month . Meanwhile, HAL is going to make about 10 a year ramping up from Zero all of last year.... just saying.

http://online.wsj.com/article/BT-CO-201 ... 01263.html


you shouldn't have :)


Top
 Profile  
 
PostPosted: 18 Feb 2012 15:19 
Offline
BRFite -Trainee

Joined: 16 Feb 2012 18:40
Posts: 6
Cain Marko wrote:

Very, very interesting Ketan, welcome to the board - you come bearing good/interesting news. Can any jingos with inside clearances to sensitive areas such as golf courses or roof tops confirm this development?

CM


Thanks CM

nachiket wrote:
Are you sure it was an LCA? Some fighter jets are difficult to distinguish from afar. A M2000 for e.g. can easily be confused with an LCA if you catch only a quick glimpse or if it's too far away. A M2000 would be a rare sight in BLR though.


I don't think it was M2000, thought i could only get a gimps of it while riding. I ride home for the lunch as it is just about a KM from working place.

As for the LCA? or what i show was coming in to landing from Marthahalli end. May be they have upgraded one of the LSP which are flying.


Top
 Profile  
 
PostPosted: 18 Feb 2012 16:40 
Offline
BRFite

Joined: 20 Feb 2011 18:41
Posts: 606
Cain Marko wrote:
ketan.sojitra wrote:
Hi All,
This is my first post although I have been lurking on BR for almost 11 years.
Am SDRE IT guy from Bangalore.

Yesterday around 2 pm show LCA with IFR probe. Are there any of them LSP or PV flying with IFR attached? Or was it LSP 6/7


Very, very interesting Ketan, welcome to the board - you come bearing good/interesting news. Can any jingos with inside clearances to sensitive areas such as golf courses or roof tops confirm this development?

CM


CM

Kakarat's photo of a scan of tejas booklet from AEROINDIA 2011 did show the IFR probe. i won't doubt if it has been carried to it's logical conclusion. so what ketan is saying may actually be true!! :mrgreen:

FWIW take a look at this -

http://www.bharat-rakshak.com/media/Aer ... 1.jpg.html


Top
 Profile  
 
PostPosted: 18 Feb 2012 16:59 
Offline
BRFite

Joined: 23 Jan 2012 20:46
Posts: 135
Location: Aerospace capital of India
It was an M2K and not an IFR equipped LCA, the M2Ks are overhauled in HAL overhaul division, so finding one shouldn't be problem at all.


Top
 Profile  
 
PostPosted: 18 Feb 2012 18:52 
Offline
BRF Oldie

Joined: 01 Jan 1970 05:30
Posts: 2155
Location: NullPointerException
raghuk wrote:
It was an M2K and not an IFR equipped LCA, the M2Ks are overhauled in HAL overhaul division, so finding one shouldn't be problem at all.


An easy way to distinguish an M2K from an LCA is the massive size of the LCA wing compared to its fuselage. M2K's wing does not look as oversized.


Top
 Profile  
 
PostPosted: 18 Feb 2012 23:21 
Offline
BRF Oldie

Joined: 04 Feb 2004 12:31
Posts: 2628
Vikram W wrote:
So Boeing is planning to make about 10 Dreamliners a month by Q4 2013, scaling up from its current 2.5 a month . Meanwhile, HAL is going to make about 10 a year ramping up from Zero all of last year.... just saying.

http://online.wsj.com/article/BT-CO-201 ... 01263.html


Just saying what? Any idea how many firm orders Boeing has for the 787 as compared to the LCA? If Boeing didn't make that many a month, they'd lose a whole bunch of new customers to Airbus' A350, since those customers will not be willing to wait till they get their 787s after 10+ years or so. Boeing replaced the anaemic 767 line with the 787 line since there were almost no orders for the 767 anymore..and then set up another one at its Everett plant just because it has so many orders for the 787..and then it went on to set up another entire 787 factory in South Carolina because even that wasn't enough.

Why would HAL set up a larger assembly line unless they can get firm orders from their one and only customer? If IAF only intends to place orders for 40 Tejas Mk1, HAL will only set up an assembly line for 10.


Top
 Profile  
 
PostPosted: 19 Feb 2012 02:58 
Offline
BRFite

Joined: 08 May 2006 13:44
Posts: 1194
Location: mumbai
Kartik wrote:
Why would HAL set up a larger assembly line unless they can get firm orders from their one and only customer? If IAF only intends to place orders for 40 Tejas Mk1, HAL will only set up an assembly line for 10.
Orders cannot be given until the design meets basic performance parameters.

In DRDO's own words http://www.drdo.gov.in/drdo/pub/dss/200 ... EMILAC.pdf
Quote:
It is seen that most of the performance parameters are deviating from the requirements.


Quote:
The Air brakes in Tejas provided at the rear spinal part of the fuselage to decelerate aircraft at higher speeds. Due to this rear location in addition to the deceleration it gives an uncommanded pitch up and directional stability reduction. Various improvement methods like perforated airbrake, updation of aero data set and fine tuning of control law gains were tried. Still the problem is not rectified completely.


Tejas airbrakes http://www.bharat-rakshak.com/media/Aer ... e.jpg.html Sukhoi airbrakes http://www.flickr.com/photos/vishwak/5436297107/ mounted close to CoG, so no such moment arm acting on the aircraft. Mirage 2000 airbrakes are mounted on wing http://rafaleair.free.fr/photo2/mirage%202000-5%20F.jpg close to CoG.

Common sense dictates such parts be close to CoG to minimize uncommanded movements. However, for reasons best known to designers, they didn’t. Simulation/Testing should have revealed this during design, but again, this went ahead.

F-16 has rear brakes, but they split open equalizing the force unlike the upward-only Tejas http://pafwallpapers.com/blog/wp-conten ... arrows.jpg

Solution
Quote:
A study taken up to utilize the main landing gear follow up door as an airbrake.
So we’ll see a plane that’ll keep opening its MLG doors in flight.

Quote:
One of the major out come of sea level trial of Tejas is that the drag of the aircraft is high such that the aircraft could not reach the supersonic Mach number at sea level.
Solution
Quote:
Nose cone extension using a Plug.
In Mk2

Quote:
Trailing Edge Extension (TEC)
Now this is interesting. Many BR members on seeing the abrupt training edge had commented that it would be draggy. http://imageshack.us/photo/my-images/88 ... 01is2.jpg/
Common Sense that airflow split at wing root leading edge should be enabled to rejoin at the wing root trailing edge.

Quote:
From the Fig. 12 it is seen that there is a sudden variation in cross sectional area at the rear end of the fuselage also. This can be minimized by the modification in the trailing edge using TEC. Fig. 15 and Fig. 16 shows the rear fuselage before and after modification.
Again, why didn’t this come up during initial design/testing.

Quote:
The fighter variant of Tejas is not meeting the STR requirement of ASR.
Atleast until 2009, there was no solution in place.
Quote:
A detailed study to implement Levcon in fighter and identification of other design constraints is under progress.


IAF has valid reasons to describe Tejas as a deformed Cheetah. Despite that 40 planes have been ordered, that is 5.5% of its authorized fighter force. FWIW, I doubt IAF will ever deploy Mk 1 in air to air combat, risking the lives of the pilot without performance requirements being met. Also, with further design changes, manufacturing will be impacted.


Top
 Profile  
 
PostPosted: 19 Feb 2012 03:10 
Offline
BRF Oldie

Joined: 11 Jan 2009 00:14
Posts: 2535
Tsarkarji we have done this so many times. Supporters of the forces insist everything should be fine before they are inducted, supporters of the tejas say, the forces inducted far inferior equipment in the past. I am not even an aviation noob, but high landing speed of MIG21 was/is considered hazardous, so why didnt the famed MIG bureau consider this while designing ? This aspect of MIG21 is taken as a characteristic of the aircraft and tactics built around it. Similarly there was something with the JAG

In similar vein cant the IAF accept it and make it better rather than coming up with newtonian statements like "it is a deformed cheetah" ? Why wasnt the IAF involved in providing design inputs during the 1990-93 timeframe ? I am sure they have a wealth of experience in operating aircraft a simple thing(the CoG thing) that could strike you(no offence intended) would have struck any iaf pilot Why didnt they communicate it then? Both sides are to be blamed hope AMCA charts a different course


Top
 Profile  
 
PostPosted: 19 Feb 2012 04:52 
Offline
BRFite

Joined: 23 Jul 2011 16:05
Posts: 246
Location: On the sofa.
Tsarkarji, thank you for the informative post.

The linked DRDO article was very interesting. By any chance, if you have more links to any other similar articles on LCA/HJT-36/Dhurv could you please share them? I would like to go through them.

Thanks.


Top
 Profile  
 
PostPosted: 19 Feb 2012 06:27 
Offline
BRF Oldie

Joined: 04 Feb 2004 12:31
Posts: 2628
tsarkar wrote:
Orders cannot be given until the design meets basic performance parameters.

In DRDO's own words http://www.drdo.gov.in/drdo/pub/dss/200 ... EMILAC.pdf
Quote:
It is seen that most of the performance parameters are deviating from the requirements.


Quote:
The Air brakes in Tejas provided at the rear spinal part of the fuselage to decelerate aircraft at higher speeds. Due to this rear location in addition to the deceleration it gives an uncommanded pitch up and directional stability reduction. Various improvement methods like perforated airbrake, updation of aero data set and fine tuning of control law gains were tried. Still the problem is not rectified completely.


I was talking about if from HAL's point of view. They won't be able to set up a larger assembly line without a larger order. As for whether or not the IAF can or cannot place a larger order for the Tejas, I don't subscribe to the theory that a few teething troubles should mean that they show dampened enthusiasm for the aircraft itself.

The pitch up issue is not a make or break type issue. The Typhoon had a major transonic pitch-up issue as late as 2002 that was solved with a major FCS update. Typhoon transonic pitch-up issue. And yet, did that mean that the Eurofighter nations said, hey lets just order a token 40 odd Eurofighter's each?


Quote:
IAF has valid reasons to describe Tejas as a deformed Cheetah. Despite that 40 planes have been ordered, that is 5.5% of its authorized fighter force. FWIW, I doubt IAF will ever deploy Mk 1 in air to air combat, risking the lives of the pilot without performance requirements being met. Also, with further design changes, manufacturing will be impacted.


Yes, why deploy a Tejas Mk1, when you have MiG-21s with even worse aerodynamic flaws that an inattentive pilot would push over the limit in the blink of an eye.


Last edited by Kartik on 19 Feb 2012 13:41, edited 1 time in total.

Top
 Profile  
 
Display posts from previous:  Sort by  
Post new topic This topic is locked, you cannot edit posts or make further replies.  [ 4018 posts ]  Go to page Previous  1 ... 73, 74, 75, 76, 77, 78, 79 ... 101  Next

All times are UTC + 5:30 hours


Who is online

Users browsing this forum: Harshad, kapio, pushkar.bhat and 16 guests


You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum

Search for:
Jump to:  
Powered by phpBB® Forum Software © phpBB Group