LCH and other Helicopters Discussion Thread

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Re: LCH discussion

Postby Rahul M » 22 Apr 2010 16:15

how would you bring weight down by increasing glass? the canopy is made of bulletproof plexiglass(sp?), it weighs as much if not more than corresponding material for the fuselage.

it can be either
i) prototype only configuration that will change in in-service helos
or
ii) IAF has asked for larger canopies for better view.

I would be tilting towards (i)

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Re: LCH discussion

Postby Brahmananda » 22 Apr 2010 16:49

how about 'Hawa Ka Jhoka"? :rotfl:

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Re: LCH discussion

Postby neerajb » 22 Apr 2010 17:33

I don't understand this, on one hand we proclaim that our armed forces, babus, media, DRDO suffers from Brochuritis and on the otherhand, here, we are nitpicking why there is so much glass, see... no other attack helo has that etc etc. If the designers feel that it is needed and if the user is happy with it, then it doesn't matter whether LCH is spherical in shape or made of wood.

Cheers....

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Re: LCH discussion

Postby narayana » 22 Apr 2010 17:53

How abt "Agni Rakshas"

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Re: LCH discussion

Postby Singha » 22 Apr 2010 17:59

the interior volume of the cockpit looks very roomy compared to the tight and trim
cockpits of the other gunships. the glass panels are far away from the people inside.

perhaps they will move to a step design and push the glasses closer to the pilots
later.

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Re: LCH discussion

Postby manoba » 22 Apr 2010 18:33

Since a lot of glass (see-through material) is used, why don't we name this beauty after our very own Bollywood houris. Kareena for sleek, size zero appearance, Pibasha or Nayantara for menacing looking, etc. Some Kerala kuttigal are really menacing looking. Once they fix their gaze upon their target. It's done. No return.

Or, how about Jungil Billy? That's a very good offer. Take it before Steve Jobs names his next OS after that. By the way the Jungil Billy is one fierce, menacing looking beast that can scare the crap out of you with its single cry (especially at the time of mating :oops: ). I am still scared of cats thanks to the Jungil Billy.

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Re: LCH discussion

Postby kmkraoind » 22 Apr 2010 19:24

How about "Panchi."

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Re: LCH discussion

Postby Rupesh » 22 Apr 2010 21:02

Folks ... can we continue the naming session in Nukkad :((

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Re: LCH discussion

Postby Viv S » 22 Apr 2010 23:00

Rupesh wrote:Folks ... can we continue the naming session in Nukkad :((


I think this would become the third time the Admin has had to transfer a namkaran session to a more appropriate thread.

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Re: LCH discussion

Postby karthik » 22 Apr 2010 23:51

Wow, Whats with the top shock absorber mounting!! Looks so flimsy. :shock:

Looks like some welded hinge is holding it on?

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Re: LCH discussion

Postby Anujan » 22 Apr 2010 23:56

I also noticed that there is a lemon under each wheel, are too many screws on the body, the rod supporting the tail rotor does not have a cover and there is too much glass.

And oh, the test pilots uniforms dont match and the shoes look old.

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Re: LCH discussion

Postby Gaur » 23 Apr 2010 00:07

^^
:lol: Good one.

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Re: LCH discussion

Postby Anujan » 23 Apr 2010 00:10

^^
You do realize that there *is* a lemon under each wheel before the first flight? HAL has gone "Indic"

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Re: LCH discussion

Postby karthik » 23 Apr 2010 00:14

No need to get all smarty pants here, i have been watching this discussions for over an decade and i know how every newbie tries to manufacture an smart question just to impress the mods,seniors and get some recognition or whatever!

The reason i asked it was because I have been learning about shock absorbers because i need to change it in my vehicle so i was curious to learn about the mounting!! Its not to prove anything here or to be negative and rant.

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Re: LCH discussion

Postby Anujan » 23 Apr 2010 00:23

You do realize that there is a process called "certification" ? And that one of the certifications is that of crash worthiness. Means stressing the landing assembly (IIRC (de)accelerations of 25g due to crashes)?

Not a nut or bolt goes in before it is twisted, turned, broken, weight measured and strength quantified & tested.

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Re: LCH discussion

Postby karthik » 23 Apr 2010 00:41

Anujan wrote:You do realize that there is a process called "certification" ? And that one of the certifications is that of crash worthiness. Means stressing the landing assembly (IIRC (de)accelerations of 25g due to crashes)?

Not a nut or bolt goes in before it is twisted, turned, broken, weight measured and strength quantified & tested.


In flight history there have always been obvious design flaws by over ambitious designers and miss haps have happened. After all HAL is not infallible and the twisting,turning,strength test etc., is actually not over and its on the way now! Static tests are far different from inflight tests, everyone knows that.

Moreover the Sara's and IJT do stand as glaring examples, i dont want to be dragged into an flame war for mentioning that and i hope this is over with this post, if you dont want to answer you can keep quite.

Personally i have already mentioned how much i love the design, its not my problem that you did not read through.

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Re: LCH discussion

Postby putnanja » 23 Apr 2010 00:52

karthik wrote:Wow, Whats with the top shock absorber mounting!! Looks so flimsy. :shock:


karthik wrote:The reason i asked it was because I have been learning about shock absorbers because i need to change it in my vehicle so i was curious to learn about the mounting!! Its not to prove anything here or to be negative and rant.
No need to get all smarty pants here, i have been watching this discussions for over an decade and i know how every newbie tries to manufacture an smart question just to impress the mods,seniors and get some recognition or whatever!

The reason i asked it was because I have been learning about shock absorbers because i need to change it in my vehicle so i was curious to learn about the mounting!! Its not to prove anything here or to be negative and rant.


karthik wrote:In flight history there have always been obvious design flaws by over ambitious designers and miss haps have happened. After all HAL is not infallible and the twisting,turning,strength test etc., is actually not over and its on the way now! Static tests are far different from inflight tests, everyone knows that.
...
Personally i have already mentioned how much i love the design, its not my problem that you did not read through.


In your first quote , you said the shock absorber looks flimsy, and that was because you looked at your two wheeler's absorber. Based on you just reading a book and looking at a picture, you can pass judgements against something that has probably gone thru multiple reviews and simulation? And you complain when members call you out on it???Look at your own posts first !!

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Re: LCH discussion

Postby karthik » 23 Apr 2010 00:56

putnanja wrote:
In your first quote , you said the shock absorber looks flimsy, and that was because you looked at your two wheeler's absorber. Based on you just reading a book and looking at a picture, you can pass judgements against something that has probably gone thru multiple reviews and simulation? And you complain when members call you out on it???Look at your own posts first !!



I said mounting and not shock absorber, if you dont know the difference keep quite, i did my engineering in Bangalore. I dont have a two wheeler i have an off-roader(4x4) whose suspension i must increase.

This discussion is done, i dont want to make it more than it should be.

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Re: LCH discussion

Postby Kartik » 23 Apr 2010 01:37

karthik wrote:Wow, Whats with the top shock absorber mounting!! Looks so flimsy. :shock:

Looks like some welded hinge is holding it on?


landing gears are tested on the ground to the limit loads. They do drop tests and they do a static strength test as well to ultimate loads. They measure both stresses and strains and so those hinges and mountings are not going to be used on the prototype unless they know it works. Add to that the fatigue tests where they'd have verified the life of hte landing gear in terms of number of landings by repeatedly applying the loads.

Don't worry, there is nothing wrong with that landing gear design.

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Re: LCH discussion

Postby karthik » 23 Apr 2010 01:51

Kartik wrote:
landing gears are tested on the ground to the limit loads. They do drop tests and they do a static strength test as well to ultimate loads. They measure both stresses and strains and so those hinges and mountings are not going to be used on the prototype unless they know it works. Add to that the fatigue tests where they'd have verified the life of hte landing gear in terms of number of landings by repeatedly applying the loads.

Don't worry, there is nothing wrong with that landing gear design.


I hope so but i think i get the theory behind the mounting now, its deliberately kept independent from the cockpit frame because any serious landing would not stress the structure and instead the mounting will either bend or crumble hence absorbing the shock without harming the frame and can be replaced later separately! I think thats the rational behind it.

Thanks Kartik.

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Re: LCH discussion

Postby Indranil » 23 Apr 2010 03:05

Anujan wrote:^^
You do realize that there *is* a lemon under each wheel before the first flight? HAL has gone "Indic"


It's a ritual in Karnataka to ride/drive over a lemon. Its part of their puja that they do to their vehicles when they first get it! And HAL is in Bangalore!

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Re: LCH discussion

Postby svinayak » 23 Apr 2010 03:17

indranilroy wrote: Its part of their puja that they do to their vehicles when they first get it! And HAL is in Bangalore!

It is not 'their' puja. It is normal during navratri.
http://www.hindu-blog.com/2009/09/shast ... pooja.html
Shastra Puja is held on the ninth day of the Navratri Festival – this is the Mahanavami day during Durga Puja. The weapons (Sastra or Astra) used by Goddess Durga are worshipped on this day. people worship the tools and objects that they use to earn a livelihood.
Shastra Puja is also known as Ayudha Puja in South India. A similar ritual held during Durga Puja is the Astra Puja.

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Re: LCH discussion

Postby Indranil » 23 Apr 2010 03:32

karthik wrote:I hope so but i think i get the theory behind the mounting now, its deliberately kept independent from the cockpit frame because any serious landing would not stress the structure and instead the mounting will either bend or crumble hence absorbing the shock without harming the frame and can be replaced later separately! I think thats the rational behind it.

Thanks Kartik.


Hazarding another guess. Notice that the mounting is actually almost in the same direction as the compression. If you draw a line through the length of the absorber, it will almost pass through the welding with the body of the mount. This is unlike most cases where the shock absorbers is almost perpendicular to the chassis. So the shock will actually travel through the length of the absorber, through the absorber mount and the body mount into the body. It would not be shear stress (trying to tear away from the weld) but to compressive stress (press against it). I believe that the part behind the joint (weld) must be fortified to take that shock.

Also the mount is in the shape of a downward "V". So in the case of a hard landing, the sides of this V will be subjected to compressive stress. And compressive strength of a metal is generally much higher than tensile/shear strength. So it should hold good.

Will wait for somebody else to answer if he/she knows the exact answer! Also as always, we all are waiting for the final version to show us the real LCH :)

By the way: was reading that an illustrated photographer called it a crocodile. What a compliment to the aesthetics of a mean machine! If I were the designer, I would have blushed up all red :oops:
Last edited by Indranil on 23 Apr 2010 03:59, edited 1 time in total.

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Re: LCH discussion

Postby Indranil » 23 Apr 2010 03:38

Acharya wrote:
indranilroy wrote: Its part of their puja that they do to their vehicles when they first get it! And HAL is in Bangalore!

It is not 'their' puja. It is normal during navratri.
http://www.hindu-blog.com/2009/09/shast ... pooja.html
Shastra Puja is held on the ninth day of the Navratri Festival – this is the Mahanavami day during Durga Puja. The weapons (Sastra or Astra) used by Goddess Durga are worshipped on this day. people worship the tools and objects that they use to earn a livelihood.
Shastra Puja is also known as Ayudha Puja in South India. A similar ritual held during Durga Puja is the Astra Puja.


You are right about Ayudh puja, but it also done when getting a vehicle in Mysore/Bangalore belt atleast ... many people here from Bangalore might testify ... atleast my Kannadiga friends had made me do it twice while I was in Mysore and Bangalore :).

Anyways lets move on :) ... no point increasing post count in this way

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Re: LCH discussion

Postby shiv » 23 Apr 2010 05:55

karthik wrote:In flight history there have always been obvious design flaws by over ambitious designers and miss haps have happened. After all HAL is not infallible and the twisting,turning,strength test etc., is actually not over and its on the way now! Static tests are far different from inflight tests, everyone knows that.


With respect sir - your stated reason for judging these things is as follows

karthik wrote:The reason i asked it was because I have been learning about shock absorbers because i need to change it in my vehicle so i was curious to learn about the mounting!!


I don't think it is a good idea to base changes in your vehicle on photographs of the first prototype of an Indian helicopter, given that you have yourself understood the fallibility of design in aviation history. A design that looks like it may fails on a helicopter may not be appropriate for your vehicle.

I know a few good mechanics who can fix shocks - but that is for the nukkad thread.

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Re: LCH discussion

Postby chetak » 23 Apr 2010 17:29

The LCH has now done 220 kmph in forward flight. They are gradually
expanding the flight envelope.

The performance at this height remains gearbox limited. The max power put out by the Shakti engine is more than that which can be handled by the current gearbox at these heights.

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Re: LCH discussion

Postby putnanja » 23 Apr 2010 23:11

chetak wrote:The LCH has now done 220 kmph in forward flight. They are gradually
expanding the flight envelope.

The performance at this height remains gearbox limited. The max power put out by the Shakti engine is more than that which can be handled by the current gearbox at these heights.


Are they looking at upgrading the gearbox at a later date?

what is the max altitude achieved so far by LCH? Any info on the tests so far? how is the handling?

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Re: LCH discussion

Postby chetak » 23 Apr 2010 23:46

putnanja wrote:
chetak wrote:The LCH has now done 220 kmph in forward flight. They are gradually
expanding the flight envelope.

The performance at this height remains gearbox limited. The max power put out by the Shakti engine is more than that which can be handled by the current gearbox at these heights.


Are they looking at upgrading the gearbox at a later date?

what is the max altitude achieved so far by LCH? Any info on the tests so far? how is the handling?


As remarked earlier, this seems to be a one off gearbox so far. No urgent thoughts in HAL on upgrading the gearbox yet.

They are doing resonance tests, both ground and air and they are tooling around at circuit height onlee.

Handling seems ok. This is a qualified statement. Bear in mind that their customers are looking to operate loads of lethal stuff hanging from pylons. Problems if any may surface at that stage. :)

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Re: LCH discussion

Postby Kersi D » 29 Apr 2010 12:46

narayana wrote:How abt "Agni Rakshas"


Why not Bharat Rakshak ?

K

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Re: LCH discussion

Postby nsarma » 29 Apr 2010 13:52

I fancy "Vajrabahoo" or simply "Vajra" for this bird, aptly meaning firing thunderbolts.
Mods please move this post to a more appropriate thread if does not fit here.

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Re: LCH discussion

Postby Dmurphy » 29 Apr 2010 15:30

nsarma wrote:I fancy "Vajrabahoo" or simply "Vajra" for this bird
IIRC, Mirage 2000 is already a Vajra.

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Re: LCH discussion

Postby Jeff Glueck » 29 Apr 2010 18:54

Saw the beauty going through paces around 5:40 pm atop CABS building
Sleek and slender , quite a presence i should say

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Re: LCH discussion

Postby Sagrawal » 30 Apr 2010 18:42

Dear Admins

I have video of first flight of LCH sourced from a Chaiwallah. Do you think its okay to share here as I haven not see any videos of LCH in public domain yet. I am not sure if its something secret which needs to be prevented from lurkers from other countires?

let me know.

Thanks

Sumit

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Re: LCH discussion

Postby nachiket » 30 Apr 2010 20:28

Sagrawal wrote:Dear Admins

I have video of first flight of LCH sourced from a Chaiwallah. Do you think its okay to share here as I haven not see any videos of LCH in public domain yet. I am not sure if its something secret which needs to be prevented from lurkers from other countires?

let me know.

Thanks

Sumit


If they haven't released official videos of the LCH yet, there's probably a reason for it. Additionally it could put your chaiwallah in trouble if they can trace the leak. We need him to keep on providing info on the LCH as the program progresses.

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Re: LCH discussion

Postby shiv » 30 Apr 2010 20:32

Sagrawal wrote:Dear Admins

I have video of first flight of LCH sourced from a Chaiwallah. Do you think its okay to share here as I haven not see any videos of LCH in public domain yet. I am not sure if its something secret which needs to be prevented from lurkers from other countires?

let me know.

Thanks

Sumit


Bhaiya - if chaiwala has no objection, put it on YouTube. Nothing to do with BR or admins.

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Re: LCH discussion

Postby Sagrawal » 30 Apr 2010 20:43

Thank you Nachiket, I was not sure because of same reason. I should keep it with me, i will try to make it to Banglaore BR meet, i can show it to guys there.

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Re: LCH discussion

Postby Gaur » 30 Apr 2010 21:00

^^
Please confirm with your panwalla for us mango peapal's sake. If your panwalla gives a go, we will also be able to ogle at lch video.

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Re: LCH discussion

Postby Sagrawal » 30 Apr 2010 21:24

Gaur wrote:^^
Please confirm with your panwalla for us mango peapal's sake. If your panwalla gives a go, we will also be able to ogle at lch video.

I will ask....

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Re: LCH discussion

Postby mandrake » 01 May 2010 00:43

Link

IR-suppressor adorns the ALH
Wednesday, 16 January 2008

The performance of indigenously developed IR-suppressor for engine exhaust duct of Advanced Light Helicopter masterminded by the Department of Aerospace Engineering, IIT Bombay is proved successful by ground tests conducted in RWR&DC HAL - Bangalore, in Dec'07. The non-specific stealth design concepts behind this critical component will soon be published in AIAA's Journal of Propulsion & Power, authored by Prof. Mahulikar & his M.Tech. students, Mr. H.S.S. Prasad & Mr. S.K. Potnuru.

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Re: LCH discussion

Postby Bala Vignesh » 05 May 2010 13:11

Sagrawal wrote:
Gaur wrote:^^
Please confirm with your panwalla for us mango peapal's sake. If your panwalla gives a go, we will also be able to ogle at lch video.

I will ask....


So what did your panwalla say about the video????


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