LCA News and Discussions

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Gagan
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Re: LCA News and Discussions

Post by Gagan »

The tiltrotor of the Osprey is also somewhat of an example of thrust vectoring. That plane has a very short take off length. Its tilt rotor in effect 'vectors' its thrust to take off very sharply, and then fly like a plane.

For all of massa's pronouncements about thrust vectoring, three of their aircraft - F-22, F-35, and Osprey now feature thrust vectoring. I am sure all three have the advantage of STO.
Last edited by Gagan on 12 Jun 2010 01:22, edited 1 time in total.
Austin
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Re: LCA News and Discussions

Post by Austin »

Gaur wrote:^^
200kg? Does that include strengthening of structure around engine and ballast added to counter cg disbalance? Or it just the weight of the TVC nozzle?
Well in simple terms if you want to add TVC to a plan vanila AL-31F , it will increase the weight of engine by just ~ 150-200 kg max , no other changes are required or mentioned.
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Re: LCA News and Discussions

Post by Indranil »

KrishG wrote:
Reminds of the Mig-35 display at Aero-India. It displayed all these maneuvers. I think if produced, the Mig-35 will be one of the supreme dog fighters around!
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Re: LCA News and Discussions

Post by Indranil »

Austin wrote:Thanks Dileep , Shiv for the reply
indranilroy wrote:P.S. Austin sahab it is not true that other countries didn't toy with the idea of having there planes have TVC. Forget about the Europeans, even the Chinese evaluated TVC for their designs. There are perfect reasons why they opted out of it in the J-11, J-10, and the J-17. The problem for the US and the Russians is that they are global leaders. They have had to find out a lot of new things. The rest of the world has inherited a lot of knowledge from them.
Evaluated in which sense , did they actually build a prototype , mastered the TVC/FCS system or they did some theoretical evaluation ?

I think every one including the Europeans understand that multi-axis TVC does bring in advantage but right now no one is ready to spead the extra mulllah build a prototype and flight test it.

Although weight is a factor but from what I have read even for AL-31FP engine with 2D TVC the additional weight added was ~ 200 kg .
A simple google search would list many more returns than what I can point out here. If you could point me to the contrary that similar evaluation was not done, I would be very grateful to know. I do not understand how you can underestimate the collective minds of so many scientists, engineers and specialists working in all those countries!

Not everything needs to be validated using a prototype, does it? For example, do you think ADA will choose the Eurojet EJ200 with or without the TVC by building prototypes around it? Prototypes are more often used for validating and not for designing!

I do not mean to be offensive but frankly, I do not understand the objective of your post.
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Re: LCA News and Discussions

Post by Shalav »

shiv wrote:No shalav. Not in this case. Gagan's picture is correct. The nozzle here is well behind the center of mass. The "up" nozzle tends to cause a nose pitch up leading to a high angle of attack causing high lift at low speed. In the Harrier the nozzles are at the center of mass.
I am 100% (400%??) certain the nozzle is down-angled for STOL. Its not the AoA which allows for short landings - its the forward velocity of the aircraft at touchdown which affects landing distance. Increased pitch leads to other complications such as loss of visibility of the runway, but more importantly at an increased AoA, V(stall) increases from that in level flight.

Normally during landing there is about 10% gap between stall velocity and touchdown velocity. An up-angled nozzle would not help in reducing touchdown velocity in any way, while at the same time stall velocity would dangerously inch closer to touchdown velocity, thereby erasing much of the margin for errors. That is why I am certain the nozzle will be down-angled.

With a down-angled nozzle, some of the weight from the aircraft is supported by the down thrusting nozzle. As you know when L=W the aircraft will fly, and on fixed wings L is generated solely by forward velocity.

When some of the W is supported by the nozzles, L requirement from the wings will be reduced, consequently forward velocity required to maintain L=W is lower, which in turn means slower V(touchdown) and shorter landing distance.
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Re: LCA News and Discussions

Post by Indranil »

Austin wrote:
Well in simple terms if you want to add TVC to a plan vanila AL-31F , it will increase the weight of engine by just ~ 150-200 kg max , no other changes are required or mentioned.
That "just" is 15-20% of the engine weight itself! To add to it the difference in airframe weight of the MKI and the vanilla MK version is not 300-400 kgs!
Also, please read this report
http://www.nasa.gov/centers/dryden/pdf/ ... H-2081.pdf
On page 4,
The vane assembly added 1600 lb, and the corresponding ballast in the forward fuselage just in front of the
cockpit amounted to 700 lb. An additional 900 lb was added with the installation of the spin chute and subsystem
modifications, which included emergency batteries, modified radome, steel reinforcement, and wiring. Thus, the total
weight increase from the basic aircraft is about 3200 lb. This increase resulted in an aft center-of-gravity shift of
4.4 in. for the empty aircraft.
Anyways, it is not a discussion based on I win or you win :).

Anyways, here I post some more interesting articles on TVC!

Though it is a vendor's article which paints only the positives, it gives a plethora of knowledge and dispels many a myth.
http://www.flightglobal.com/articles/20 ... phoon.html

and this one http://www.allbusiness.com/professional ... 119-1.html
Last edited by Indranil on 12 Jun 2010 03:24, edited 1 time in total.
Gagan
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Re: LCA News and Discussions

Post by Gagan »

Shalav, I suspect you are correct.
So this illustration of mine shows the plane, using the thrust nozzle as an additional control vector, going into a high AoA. It is going to stall, because the velocity is going to drop sharply, because the entire wing is going to act as an airbrake. Besides, the moment it goes into the stall, it is going to drop like a rock.
Image

So the thrust nozzle now has to turn down quickly to 'lift' the plane, yet give it some forward velocity. The plane's high AoA is maintained by the canard, LREXs, elevons and the thrust nozzle.

Image
The additional exhaust on either side of the rear fuselage provide the plane with a stabilized, three point posture to prevent it from toppling sideways.

Interesting.
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Re: LCA News and Discussions

Post by Indranil »

Shalav wrote:
shiv wrote:No shalav. Not in this case. Gagan's picture is correct. The nozzle here is well behind the center of mass. The "up" nozzle tends to cause a nose pitch up leading to a high angle of attack causing high lift at low speed. In the Harrier the nozzles are at the center of mass.
I am 100% (400%??) certain the nozzle is down-angled for STOL. Its not the AoA which allows for short landings - its the forward velocity of the aircraft at touchdown which affects landing distance. Increased pitch leads to other complications such as loss of visibility of the runway, but more importantly at an increased AoA, V(stall) increases from that in level flight.

Normally during landing there is about 10% gap between stall velocity and touchdown velocity. An up-angled nozzle would not help in reducing touchdown velocity in any way, while at the same time stall velocity would dangerously inch closer to touchdown velocity, thereby erasing much of the margin for errors. That is why I am certain the nozzle will be down-angled.

With a down-angled nozzle, some of the weight from the aircraft is supported by the down thrusting nozzle. As you know when L=W the aircraft will fly, and on fixed wings L is generated solely by forward velocity.

When some of the W is supported by the nozzles, L requirement from the wings will be reduced, consequently forward velocity required to maintain L=W is lower, which in turn means slower V(touchdown) and shorter landing distance.
Shalav you are partially right. But the nozzle is indeed the way Gagan has pointed out. It is used as a elevator to point the tail down. In fact the nozzle almost works in unison with the elevator (if any)! You came almost to right conclusion except your last part. If you do what you say, the plane will nose dive on the run way!

Even when taking off the Tejas doesn't have a extra plane to point the nose up (canard) or the tail down (elevator), hence a TVC would help there and the nozzle will be in the direction as Gagan painted :).

notice this video at 12 secs:
http://www.youtube.com/watch?v=-hq_RTaThNI

notice the paddles of the X-31 very carefully and you will see what I mean.
http://www.youtube.com/watch?v=7eks40ipYmc&NR=1
Last edited by Indranil on 12 Jun 2010 04:06, edited 1 time in total.
Gagan
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Re: LCA News and Discussions

Post by Gagan »

But the N-LCA has a prominent LREX. I am sure it will help in the short carrier borne take offs, by helping the nose point skywards.

Now if they only put in a TVC, mine/our conjectures will come true.
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Re: LCA News and Discussions

Post by Viv S »

Gaur wrote:^^
But do not the heavier (and thus larger) a/cs' control surfaces have larger surface area to counter this?
I mean, the high moment of inertial will hinder any movement that changes the direction of flight (which is almost every maneuver that the heavy a/c can hope to make). So does that mean that a heavy a/c will always be less agile than a light a/c?
You're absolutely right. A large aircraft is not necessarily less maneuverable than a smaller one. I assumed the question was with regard to the need to shed weight/increase thrust in the Tejas. :|
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Re: LCA News and Discussions

Post by Indranil »

Gagan wrote:Now here if we take the example of the F-35, not only does it have a TVC nozzle at the end, it also has a lift fan in the middle-front so that it can do a very STO.
The F-35 design is a more refined concept of what we are discussing here.
I am not absolutely sure but as far I remember the lift fan is for VTOL. They wanted a 4-point thrust control for much better stability on all axises (they have 2 more small ones in the wings) than the Harriers (which till now was the only successful VTOL fighter).

But I think they had huge problems with the fan (and are running into new ones with debris being sucked in by the fan). I don't know why I feel it will be maintenance heavy. I was reading something about how they managed to engineer it in first place. I must say, its an amazing engineering feet.
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Re: LCA News and Discussions

Post by Indranil »

Gagan wrote:
So the thrust nozzle now has to turn down quickly to 'lift' the plane, yet give it some forward velocity. The plane's high AoA is maintained by the canard, LREXs, elevons and the thrust nozzle.

Image
The additional exhaust on either side of the rear fuselage provide the plane with a stabilized, three point posture to prevent it from toppling sideways.

Interesting.
Sir you are complicating it, unnecessarily. It is simple isn't it. Slow down but not to your stall speed :). If you know how elevators are used during landing, then just replace the elevators with the nozzle, you would arrive at the direction in which the nozzle points.

There are no dramatic change in nozzle direction and all :).
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Re: LCA News and Discussions

Post by Indranil »

indranilroy wrote:
Gagan wrote:Now here if we take the example of the F-35, not only does it have a TVC nozzle at the end, it also has a lift fan in the middle-front so that it can do a very STO.
The F-35 design is a more refined concept of what we are discussing here.
I am not absolutely sure but as far I remember the lift fan is for VTOL. They wanted a 4-point thrust control for much better stability on all axises (they have 2 more small ones in the wings) than the Harriers (which till now was the only successful VTOL fighter).

But I think they had huge problems with the fan (and are running into new ones with debris being sucked in by the fan). I don't know why I feel it will be maintenance heavy. I was reading something about how they managed to engineer it in first place. I must say, its an amazing engineering feet.
I was wrong F-35 uses the Fan for STO too!

http://www.youtube.com/watch?v=XIsIzjVi7j4
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Re: LCA News and Discussions

Post by Juggi G »

Eurojet Offers Dual-Use Engine for LCA
K. V. Prasad
BERLIN, June 12, 2010


“The Engine will be Competitive in Many Aspects”

Eager[/size] to join hands with the Defence Research and Development Organisation (DRDO) and its associates in the development of India's Light Combat Aircraft ‘Tejas-Mark II,'[/color] the Eurojet consortium is offering its Engine that could be Tweaked to Work on its Naval Version.

“We are Offering Two Variants of the EJ200, Bidding for the India's LCA Mark-II which can be Altered through a Software change to Suit the Requirements for the Naval Version of the LCA,”[/color] Eurojet Vice-President Sales Paul Hermann told a group of journalists here.


The Aeronautical Defence Agency (ADA), the nodal agency for the design and development of the LCA under the overall supervision of the DRDO, had sought a proposal from the EJ200 and the American GE414 engine. The order will be initially for 99 engines with 10 of these in ready-to-use condition. There is an option for additional 49 engines order.

Eurojet Chief Engineer Wolfgang Sterr said there were over 1,500 EJ200 engines for the 700-plus Eurofighter Typhoon aircraft under contract to six nations. He said the engine was suitable for the LCA and could be used for the naval variant that the ADA was working on.

The Eurofighter is in the race for the 126 Medium Multi-Role Combat Aircraft that the IAF is acquiring.

The naval version requirement of greater thrust for take-off from an Aircraft Carrier can be met Without Altering the Hardware of the Engine. With a Switch of Software the EJ200 can be used for the Naval Variant and Vice-Versa.[/color]

While the company preferred not to make any direct comment on the Price Tag, EJ Sales Director Adrian Johnson, said It would be Competitive in many Aspects through Low Life Cycle Costs, Transfer of Technology and Offering Partnership to India for Future Development and Enhancement of the Engine and its Systems[/size].
The officials said, “If the Eurojet makes the grade, the organisation could also share its expertise in India's quest to develop indigenous Kaveri engine. We have experienced the challenge India is facing, At Rolls-Royce, it took us 100 years to get where we are…,”Mr. Johnson said.

The Eurojet consortium includes Rolls-Royce (England), MTU (German), ITP (Spain) and Avio (Italy).[/color]
Eurojet Offers Dual-Use Engine for LCA
Last edited by Rahul M on 12 Jun 2010 10:17, edited 1 time in total.
Reason: please go easy on colours and large fonts.
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Re: LCA News and Discussions

Post by shiv »

Shalav wrote: Normally during landing there is about 10% gap between stall velocity and touchdown velocity. An up-angled nozzle would not help in reducing touchdown velocity in any way, while at the same time stall velocity would dangerously inch closer to touchdown velocity, thereby erasing much of the margin for errors. That is why I am certain the nozzle will be down-angled.

With a down-angled nozzle, some of the weight from the aircraft is supported by the down thrusting nozzle. As you know when L=W the aircraft will fly, and on fixed wings L is generated solely by forward velocity.
.
shalav - there is one fatal problem with what you are saying. What is the axis of thrust relative to the CG of the aircraft? In Gagans picture we have to assume that the axis of thrust is well behind the CG.

If the nozzle is behind the CG and it points down it will tend to rotate the plane on its pitch axis - i.e the nose will slam into the runway as the tail rises.

Landing is nose down only until the runway is close after which there is a "flare" as the nose is pitched up and aircraft land with nose up causing tailwheels to touch down first, with nose well up (high AoA)

If the nozzle points up the nose will get pitched up (tail gets pushed down, and nose goes up by rotation on pitch axis) You are saying that this is bad because of visibility and Gagan says it will stall. Both are not necessarily correct. If the nozzle up angle is appropriate and the FBW software is written correctly, the nozzle up position will cause a high AoA that can be maintained perfectly so that there is enough forward velocity to prevent stall while keeping the aircraft at the lowest possible speed. Only problem is the aircraft will still have to settle on the runway at just above stall speed with nose up, unless there is a way of making it hover and sit on its tail.(One aircraft was designed to do just that)

A nozzle down is fine only and only if the axis of thrust coincides with the CG. In the F-35 this is achieved by a lift fan in addition to the nozzle. In the Harrier the nozzle is mid-body and is situated at the CG.

Recall that the maneuver described in the video above is "post stall loop" (Kulbit maneuver) is because the nozzle is behind the CG and causes the aircraft to rotate on its pitch axis. Apart from the Kulbit the most spectacular example of rotation of an object about its pitch axis is the Brahmos vertical launch video. But since it is OT here I will describe it in the newbie thread.
Last edited by shiv on 12 Jun 2010 08:49, edited 1 time in total.
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Re: LCA News and Discussions

Post by shiv »

indranilroy wrote:
But I think they had huge problems with the fan (and are running into new ones with debris being sucked in by the fan). I don't know why I feel it will be maintenance heavy. I was reading something about how they managed to engineer it in first place. I must say, its an amazing engineering feet.
Saar you are absolutely right. That, and the extra weight of all this, is why they have 3 versions of F 35 and only one has this engine. The engine is a great engineering feat but let me make a prediction that the technology is too fiddly and complex and expensive to have widespread use. It will be "niche market" like the Harrier. The advent of the Harrier did not create a whole lot of Harrier clones and refinements to be built. A new tech that is world beating and easy and reliable gets copied and propagated. Clearly the Harrier was great, but not in terms of evolution and survival. All OT
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Re: LCA News and Discussions

Post by David Siegel »

Tejas LSP-2 and LSP-3 complete second phase of hot weather trials in Nagpur
http://idrw.org/?p=1990

Light combat aircraft (LCA) ‘Tejas’ which is scheduled to attain Initial Operational Clearance (IOC) by this year-end has undergone the second phase of hot weather trials in the past one week at the AirForce station in Nagpur.
The first phase of hot weather trails were conducted at the same venue in May-Jun 2008. On both occasions, the trials were very well supported by Air Force Station Nagpur.
The objective of the current phase of hot weather trials is to prove that the aircraft is in IOC configuration with the weapon system and sensors integrated.
During the trials, the two Tejas aircraft have undertaken trial sorties especially to check out the aircraft systems such as Digital Flight Control Computer, Avionics Systems, Multi Mode Radar, RWR and the Electrical and Environment Control Systems under extremely high ambient temperature conditions up to 45 degree Celsius.
The trial team consisted of IAF flight test crew from the National Flight Test Centre (NFTC) and Scientists/Engineers from Aeronautical Development Agency (ADA), Hindustan Aeronautics Limited (HAL), Bangalore, ADE, NAL, CEMILAC and DGAQA, defence release said.
During the test flights, data, video and audio from the test aircraft were transmitted in real time through the fibre optic connectivity provided by the Air Force AFNET to NFTC Bangalore, for closer monitoring and detailed analysis.
This facility has proven to be very effective in optimising overall flight test effort, while enhancing flight test safety, it said.
The trial team was able to achieve all the objectives during the week long hectic trials.
The LCA is progressing steadily towards achieving IOC by end of December 2010 and subsequent entry into service under the able guidance of P S Subramanyam Director, ADA and the optimal flight test planning under the leadership of Air Commodore Rohit Varma VM, Project Director (Flight Test) of NFTC, the release from defence PRO in Nagpur added.
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Re: LCA News and Discussions

Post by neerajb »

shiv wrote:In the Harrier the nozzle is mid-body and is situated at the CG.
Shiv ji harrier employs four nozzles for VTOL. The forward two are fed with bypass air from the fan, rear two uses the exhaust. The four nozzles are synchronized by a chain drive so that they act in unison.
It was effectively built around the Pegasus engine, with large intakes on each side of the aircraft and the four rotating exhausts, which were turned by a chain-drive system, arranged around the aircraft's center of gravity.


http://www.wingweb.co.uk/aircraft/Harri ... part1.html

Image

Cheers....
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Re: LCA News and Discussions

Post by shiv »

neerajb wrote:
shiv wrote:In the Harrier the nozzle is mid-body and is situated at the CG.
Shiv ji harrier employs four nozzles for VTOL..
Neeraj - this is OT
My reply here
http://forums.bharat-rakshak.com/viewto ... 36#p887136
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Re: LCA News and Discussions

Post by shukla »

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Re: LCA News and Discussions

Post by shiv »

It is interesting to speculate on how any air Force inducts and dovetails a new fighter into its service. In the ideal scenario the air force would have given a set of requirements that have been met in toto by the supplier and the fighter just slots itself in.

But that ideal is absent for most countries of the world. A fighter with some capabilities joins the force and that figther has to replace a pre-existing obsolete fighter. Assuming that "background basics" like serviceability and spares and reliability have all been taken care of and the new fighter is "fit to fly" the next question might be how much better is the new fighter than the old one in given roles. If it is not better, what measures can be taken to ensure that the role is fulfilled despite and inferior fighter.

If you look at LCA as MiG 21 replacement and a step into the future you need to ask how two primary roles fulfilled by the MiG 21 may be taken care of by the LCA.

I will speculate on strike first and air defence later. In the strike role I suspect the LCA will end up being better than the Mig 21 primarily because of better hauling capacity and better avionics. So the real toss up is air defence.

Again, a better radar and BVR missiles as well as some useful stealth may give the LCA BVR capability superior to the MiG 21. But how about close in engagements? Can the LCA in its current "mark 1" configuration score over the MiG 21 in all aspects of an air combat role? I think a a pilot flying an LCA will find it far easier to fly and beyond this what will be done at Sulur will be to fly off the LCA against various other fighters to assess its capability and create new tactics to take advantage of its capabilities and cover any weaknesses.

Cope India showed how weaknesses can be neutralised by tactics and surely that is what will be done with the LCA as well. Provided the LCA is kept continuously serviceable with no delays and shortages of spares, I am certain he LCA will come into its own as a great fighter.
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Re: LCA News and Discussions

Post by Austin »

^^^ JMT.... It pleasantly surprises me that a modern 4th Gen Fighter with all bells and whistles would be compared with a supersonic fighter that was designed and induced in early/late 50's speaks good about the design and its operator , Gurevich and Mikayon would be smiling from their grave reading Shiv'ji post.
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Re: LCA News and Discussions

Post by shiv »

Austin wrote:^^^ JMT.... It pleasantly surprises me that a modern 4th Gen Fighter with all bells and whistles would be compared with a supersonic fighter that was designed and induced in early/late 50's speaks good about the design and its operator , Gurevich and Mikayon would be smiling from their grave reading Shiv'ji post.
I am certain that they are already smiling in the knowledge that a "4th gen" fighter would be a replacement for the 1960 (or so) MiG 21 after 2015!

Equally amusing would be an F-16 as an MRCA winner. The F16 was designed as an answer to the way the MiG 21 was an aircraft that could "turn on a dime". More seriously the LCA must exceed the MiG 21 for it to be a credible replacement. My post was only to point out that the LCA is likely to exceed the MiG 21 in all respects - but very little is know in public about the LCA's handling in a dogfight. Surely that is what will get tested when it enters service and tactics will be developed around that.
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Re: LCA News and Discussions

Post by Austin »

True , How LCA would perform in the IAF will be known when IAF get accustomed to the bird during IOC/FOC phase , tactics ,maintenance procedure , ground handling and other documentation will be developed in that phase. LCA dog fighting capability should be as good as any 4th Gen fighter out there , its trump card will be its nose with a decent aperture size radar and its small size over other 4th gen fighter assuming other key flying qualities are on par.

I am sure IAF will be conducting exhaustive BFM with the other types they operate.
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Re: LCA News and Discussions

Post by Bala Vignesh »

^^ Might even send it to the Garuda or Indradhanush to validate its BFM capability once the basic tactics are developed...
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Re: LCA News and Discussions

Post by Gaur »

I have made 3d model of Tejas. Here are two renders. Hope you like it. :)

http://fc01.deviantart.net/fs71/f/2010/ ... atgaur.jpg
http://fc07.deviantart.net/fs71/f/2010/ ... atgaur.jpg
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Re: LCA News and Discussions

Post by nits »

Gaur wrote:I have made 3d model of Tejas. Here are two renders. Hope you like it. :)

http://fc01.deviantart.net/fs71/f/2010/ ... atgaur.jpg
http://fc07.deviantart.net/fs71/f/2010/ ... atgaur.jpg
Hey Gaur.... its really nice... perfect beauty on my desktop now :)

BTW where are they headed over the snow mountains ;) towards China :evil:
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Re: LCA News and Discussions

Post by Bala Vignesh »

Nice one Gaur ji.... You make them appear very TFTA...
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Re: LCA News and Discussions

Post by Gaur »

nits wrote: BTW where are they headed over the snow mountains ;) towards China :evil:
Why so angry? I do not know the mountain location as I got the image through google. But even if its China, shouldn't the right emicon for that be :twisted: ? I guess Tejas flying over China would be most jingo's ultimate dream? :wink:
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Re: LCA News and Discussions

Post by mody »

Shiv,
Actually the LCA's capabilities should be compared against Mirage 2K rather then MIG-21.
The Mirage may have better range and a slightly higher payload capacity but in terms of avionics, radar, BVR capability, Pricision strike capability and overall flight characteristics, with its digital FBW systems, the LCA would be much closer to the Mirage rather then the the MIG-21. Also with in-flight refuelling, the range limitation of the LCA as compared to the Mirage gets mitigated to an extent.

For that matter has the IAF ever pitted the Mig-21 Bisons against the Mirage 2K and how do the capabilities of these two fighers stack up? The Mirage will be better in precision guided ground attack roles as I think, but can it always come out on top in BVR and close in dog fight engagements as well?
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Re: LCA News and Discussions

Post by K_Rohit »

http://www.livefist.blogspot.com/

Is that LSP-2 or 3?

Also, we hear 2 pieces of news.

1) The hot weather trials are being repeated since they have to be done with IOC-level capability aircraft

2) LSP-2 and 3 are in Nagpur for the hot weather trials

Does this mean that LSP-2 and 3 have now been upgraded to full IOC level capability, including the radar?
NRao
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Re: LCA News and Discussions

Post by NRao »

Actually the LCA's capabilities should be compared against Mirage 2K rather then MIG-21.
The LCA's target was the F-16C.
Gagan
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Re: LCA News and Discussions

Post by Gagan »

Gaur,
Great rendering! Simply beautiful.

So this is 3ds Max. I'll see if I can get it.
Rahul M
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Re: LCA News and Discussions

Post by Rahul M »

parijat, really nicely done.
a few observations,
>> may be you can fill out the nose-cone a bit, it's quite curvy in real life, not a thin perfect cone. if you have modeled the cone separately it's just a matter of pulling a set of vertices in a circle to achieve the proper shape.
>> the ram air intake on the base of the tail is absent
>> the small appendages on the vertical tail for measuring air-speed (?) can be added
>> the lines for the air-brakes at the base of the tail is missing.
>> add a little bright orange to the drogue chute cap ? :)
maitya
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Re: LCA News and Discussions

Post by maitya »

shiv wrote:
Austin wrote:^^^ JMT.... It pleasantly surprises me that a modern 4th Gen Fighter with all bells and whistles would be compared with a supersonic fighter that was designed and induced in early/late 50's speaks good about the design and its operator , Gurevich and Mikayon would be smiling from their grave reading Shiv'ji post.
I am certain that they are already smiling in the knowledge that a "4th gen" fighter would be a replacement for the 1960 (or so) MiG 21 after 2015!
Shivji, smiling or non-smiling by the original designers apart, the upscaling of the various generations though all these years are mainly (not only, but *mainly*) based on avionics and materials (to a lesser extent). And, ironically, MiG-21s are the best examples of that ...

The Bisons, per IAF, were eight times more effective than a 21M/F/FL ... the quote (from IAF) went like "a bison does what eight F/FLs would have done" (not an exact quote). There was no change in the airframe or flight characteristics but "operationa effectiveness" were enhanced by such an large extent by an avionics upgrade.

So it's the avionics that has to be the key differentiator between LCA and the Bisons and 27s it seeks to replace. And, now that the basic flight characteristics have been proven and baselined, our discussion should also center around whatever pittance is known in the public domain about avionics.
For example,
i) the Bison program always intended but failed to incorporate an internal SPJ - while they could shoe-horn one (a single-band most probably) in a 27 upgrade.
LCA from day one is designed to carry one internal - but will that cover atleast like low (E/F) to mid (G/H) to high (I/J) bands (i.e. 2 to 20Ghz range) is not known - what is known however, per reports from K Prasad/rakall from AE2007, an indigenous capability exists on internal SPJ covering 1 to 20GHz.

ii) the Kopyo radar's detection/tracking range (3 sqm target size) is advertised to be around 75/50Km respectively - plus it's limitation of tracking +/-45deg only - how does these stack against the current MMR (the slotted array one - AESA will come when it comes)

iii) no IRST on both - what is the impact/limitation it imposes vis-a-vis an emergency AA capability (specially on low-low mission profile where the radar would most probably be eitehr switched-off or mostly be operating on a terrain following/mapping mode)

iv) will LCA have a full-fledged MIDS/Link-16 datalink or put-up with INCOMs and it's piddly 8kbps capability

so on and so forth ...
shiv
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Re: LCA News and Discussions

Post by shiv »

maitya wrote: the upscaling of the various generations though all these years are mainly (not only, but *mainly*) based on avionics and materials (to a lesser extent). And, ironically, MiG-21s are the best examples of that ...
It is the deep irony here that made me sneakily start off with a post comparing the LCA with the the MiG 21 it is supposed to replace, rather than the Mirage of F-16 it might have been expected to emulate. Pardon my sentimentality.

We had a flying dart in 1962 that could fly as far as a Prithvi and carried two half baked K-13 Sidewinder copies. The IAF in that era had no choice. I am sure the would have wanted an F-4, but eventually the IAF did marvellously with the MiG 21 and were probably the principal force behind its continued development.

Whatever the design rationale behind the MiG 21 I am certain that Messrs Mikoyan and Gurevich both learned some lessons from the IAF about what an Air Force that was in hot wars wanted. Our own desi designers deserve to have a chance to interact with the IAF the way the IAF has interacted with firangi designers out of sheer necessity.

Hopefully the LCA will come out a real winner in more ways than one.

As an aside I have two videos of Vayu Shakti from different years of MiG 21s dropping KAB 500s. Both times it has been smack-bang on target. Mikoyan and Gurevich designed a daytime interceptor originally.
chackojoseph
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Re: LCA News and Discussions

Post by chackojoseph »

shiv wrote: Our own desi designers deserve to have a chance to interact with the IAF the way the IAF has interacted with firangi designers out of sheer necessity.

Hopefully the LCA will come out a real winner in more ways than one.
For example, the New DRDO LGB kit.
NRao
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Re: LCA News and Discussions

Post by NRao »

PG,

Nicely done.

BUT, be careful of scope creep:
...............
a few observations
......................
The nemesis of the LCA in real life too. : )
chackojoseph
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Re: LCA News and Discussions

Post by chackojoseph »

Gaur wrote:I have made 3d model of Tejas. Here are two renders. Hope you like it. :)

http://fc01.deviantart.net/fs71/f/2010/ ... atgaur.jpg
http://fc07.deviantart.net/fs71/f/2010/ ... atgaur.jpg
Nice. Please show it above Latitude: 39° 55' 44 N, Longitude: 116° 23' 18 E
Gaur
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Re: LCA News and Discussions

Post by Gaur »

Bala Vignesh, Gagan, NRao: Thanks. I am glad you guys liked it. :)

RahulM: Thanks. And yeah, I am aware of those problems. And though it will not be difficult to model the deficiencies away, any changes I make now will need me do the unwrap again (which is basically unfolding the surface of model into a flat surface on which we can paint). This is a really tedious and boring task and I am very bad at it.
Anyhow , I now plan to spend my leisure time to model twin seater FGFA and not to mention that I am too lazy to do any changes in lca now. :mrgreen:

chackojoseph: If I get my hands on some good aerial shots, then sure. :twisted:
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