LCH and other Helicopters Discussion Thread

Cybaru · Post by **Cybaru** » 30 Mar 2010 22:50

Nice!!

Kartik · Post by **Kartik** » 30 Mar 2010 22:54

nukavarapu wrote: I was under impression for sometime that the rear wheel is just gonna stick out straight, but looking at the pics, the rear wheel has a pneumatic lever to pull it up, but I don't see any significant space on the tail to pull the rear wheel in. Is it just going to stick to the tail on bottom side and be outside horizantally during flight compared to vertical position while landing or hovering??? Any gyan wud be greatly appreciated !!!

No bhai, that is not a pneumatic lever for pulling it up. Its called a shock strut, and comprises the oleo.

The exposed metal that you see is the length of the oleo stroke..that is how much it can move up (its called a fluid spring), displace hydraulic fluid or both hydraulic fluid and air for a oleo pneumatic system and absorb shock. The length of that oleo stroke (also called vertical axle travel) means that its designed to take real punishment while landing. i.e.absorb plenty of kinetic energy. That is due to the higher crashworthiness requirements for an attack helicopter.

The vertical axle travel required is estimated based on what is the permissible landing load factor (also known as reaction factor). And it should be able to take the limit loads without any permissible deformation..that limit load will be decided based on what is the worst case in which the pilot lands operationally. Multiply it by a factor of 1.5 and you have your ultimate load and that is the load at which the landing gear should still not fail, but if it suffers a permanent set, its considered alright.

What one cannot tell is the oleo's internal construction and whether its a single stage/two stage/mixing type or separator type oleo design. Could well be a single stage to keep it simple and cheap. OTOH, two stage oleos provide varying spring characteristic and are useful for operation if the LCH needs to taxi on rough airfields. If not, and if it only needs to land, the single stage is sufficient.

All in all, a simple robust landing gear design but the length of the stroke made it clear that it was designed to take a really heavy landing.

And its going to be in that position during flight. No retraction is required. Its more complicated to have a retraction mechanism with the actuators, back up system in case it fails to come back out and space is required if its to be pulled into the fuselage, plus you need doors for that which means added hinges and actuators. For weight constrained designs, every kg of weight removed is a performance gain, so its not needed. All that additional effort and you'll get a miniscule reduction in RCS or drag.

These are all mandatory requirements for certification so the performance of the landing gear would've been tested extensively on ground rigs, with drop tests and other tests that certify its usage.

Ashish J · Post by **Ashish J** » 30 Mar 2010 22:58

@ Rahul, Martin and Mr Gaur..

Got your point..pardon me for the post..

Bala Vignesh · Post by **Bala Vignesh** » 30 Mar 2010 23:01

Looks good... There is a tad resemblance to the Dhruv but seems to be a fresh design from ground up... I pray that the test program faces no hiccups and that these birds get inducted in good quantity...

Added Later..
I know this may sound crazy but, can LCH be operated from naval ships??

jimit · Post by **jimit** » 30 Mar 2010 23:01

Thanks Rahul.

Kartik · Post by **Kartik** » 30 Mar 2010 23:04

neeraj wrote:LCH looks good. However the cockpit is a bit too much exposed. Would have preferred a higher back seat and less glass on the cockpit like this one has. Maybe they needed to put this much glass due to the weight. Hopefully the final version will address these issues.

Great effort by HAL.

exactly my gripe as well..the canopy is too large and the cockpit is far too exposed. They need to reduce it if possible to make it safer for the pilots..the perspex glass will be bullet-proof on the sides, but still too much surface area. This is the only gripe I have with this design as of now. with all the modern electro-optic systems that gunships have, having excellent visibility is not the most important thing, but from all the designs I've seen coming out of HAL and ADA, the emphasis on visibility for the pilots is very clear (Dhruv, IJT, Tejas twin-seater)..maybe the IAF and IA are very adamant on that..

chetak · Post by **chetak** » 30 Mar 2010 23:16

Kartik wrote:
exactly my gripe as well..the canopy is too large and the cockpit is far too exposed. They need to reduce it if possible to make it safer for the pilots..the perspex glass will be bullet-proof on the sides, but still too much surface area. This is the only gripe I have with this design as of now. with all the modern electro-optic systems that gunships have, having excellent visibility is not the most important thing, but from all the designs I've seen coming out of HAL and ADA, the emphasis on visibility for the pilots is very clear (Dhruv, IJT, Tejas twin-seater)..maybe the IAF and IA are very adamant on that..

Guys,

It's still very much a work in progress and it has an extremely long way to go before it arrives somewhere near its final form and shape.

Hope that they keep it simple and sturdy and not mess it up by attempting to do too much while trying to please too many people.

chetak · Post by **chetak** » 30 Mar 2010 23:23

Bala Vignesh wrote: Added Later..
I know this may sound crazy but, can LCH be operated from naval ships??

?? To what end, saar ??

Want them to go after basking submarines?

With no blade fold, no Naval CO will be comfortable with the LCH tied down on the deck. Anything more than sea state three or so will probably cause damage.

Bala Vignesh · Post by **Bala Vignesh** » 30 Mar 2010 23:30

chetak wrote:
Bala Vignesh wrote: Added Later..
I know this may sound crazy but, can LCH be operated from naval ships??
?? To what end, saar ??

Want them to go after basking submarines?

With no blade fold, no Naval CO will be comfortable with the LCH tied down on the deck. Anything more than sea state three or so will probably cause damage.

No sir, Not after Basking Submarines, sir... I had hoped to deploy them on our naval units that go on anti piracy duties the world over.. The sight of a dedicated attack helicopter should scare the s**t out of the pirates... Also the spin off includes operations off the CG OPV's that can to protect out coastlines from 26/11 style insertion being repeated...

As for the protection from sea, its possible to Marine-ise it... Like we did with Dhruv...

As i have said earlier, i know this sounds completely nuts but just couldn't stop from asking...

Rahul M · Post by **Rahul M** » 30 Mar 2010 23:37

chetak wrote:
Bala Vignesh wrote: Added Later..
I know this may sound crazy but, can LCH be operated from naval ships??
?? To what end, saar ??

Want them to go after basking submarines?

With no blade fold, no Naval CO will be comfortable with the LCH tied down on the deck. Anything more than sea state three or so will probably cause damage.

not on the destroyers or frigates but on the LPD type ships ? I think that's a distinct possibility.

JimmyD · Post by **JimmyD** » 30 Mar 2010 23:40

Rahul M wrote:
I wonder if they are considering IR suppressor attachments in the design at all later on, given how the exhaust is pointing up.
apparently IR suppressors eat in the power figures so that's an interesting question. we did retrofit them on the hinds though.

I seem to remember reading something on BR about some university in India being tasked to determine ways to reduce the IR signature for the LCH. (Will try to google and post references).

However, when looking at the photo of the LCH hovering, there doesn't seem to be any distortion in the picture due to the exhaust gases, i.e. there's no visible trail of hot gases. So perhaps something has been incoporated internally?

Kartik · Post by **Kartik** » 30 Mar 2010 23:42

Ashish J wrote:Matlab,, its seems only rear seat and a couple of changes are done from Dhruv WSI in LCH.
The finishing also looks a bit off....
Sori 2 insert a -ve comment, though i also feel elated dat it has finally taken off

thanks for your comments. yes only rear seat inserted baaki all same to same. shown your knowledge ? EDIT.

Kartik · Post by **Kartik** » 30 Mar 2010 23:43

Raja Bose wrote:Looks very nice!

The stub wings seem to have positions for 2 hard points each. I wonder if they are considering IR suppressor attachments in the design at all later on, given how the exhaust is pointing up.

What is the % of parts common with the Dhruv - might help ease the logistics at high altitude areas and simplify maintainance.

IR suppressors affect the performance of the helicopter very significantly. If you want a helo to operate at high altitudes its better not to feature major IR suppressors.

chetak · Post by **chetak** » 30 Mar 2010 23:46

Bala Vignesh wrote: As for the protection from sea, its possible to Marine-ise it... Like we did with Dhruv...

As i have said earlier, i know this sounds completely nuts but just couldn't stop from asking...

Bala Vignesh ji,

Well, at least that was thinking out of the box!!

Never heard of a marinised attack helicopter!!

You could just as easily arm a naval chetak with a multi barrel LMG in the rear cabin, operated by the Aircrew Diver. Complete with a trap to collect the spent shells and also mechanically limited arcs of fire so that the excited ACD does not shoot off his own tail rotor!!

Seriously, it would be too heavy and consequently have very short legs. Also, Naval regulations forbid the embarkation of a non folder.

Bob V · Post by **Bob V** » 30 Mar 2010 23:48

aaah !...finally the day has come....those #@$% kept this mujahid waiting since march '08 and just when the time for glory neared, they booted me out of that place..

congratulations to sharma,sheriff & team.

chetak · Post by **chetak** » 30 Mar 2010 23:51

Raja Bose wrote:
What is the % of parts common with the Dhruv - might help ease the logistics at high altitude areas and simplify maintainance.

Raja Bose ji,

The entire ( engines + transmission ) is common.

Rahul M · Post by **Rahul M** » 30 Mar 2010 23:54

chetak wrote: Never heard of a marinised attack helicopter!!

what about US marines' cobra ?

I do think we might see such a thing in IN eventually, deployed off amphibs.

You could just as easily arm a naval chetak with a multi barrel LMG in the rear cabin, operated by the Aircrew Diver.

well, if naval chetak says naval chetak with LMG is improbable who am I to argue with that ?

Raja Bose · Post by **Raja Bose** » 30 Mar 2010 23:55

Kartik wrote: IR suppressors affect the performance of the helicopter very significantly. If you want a helo to operate at high altitudes its better not to feature major IR suppressors.

Quite correct. My question was more in the context if LCH gets tasked for the plains or deserts - IR suppressors afaik are not permanently attached to the fuselage (atleast the Hind ones). Or perhaps LCH role is for HA areas only.

@chetak - the chin looks the same too. I really hope they maximize the commonality of parts as much as feasible in the chankian SDRE way.

chetak · Post by **chetak** » 30 Mar 2010 23:56

Rahul M wrote: not on the destroyers or frigates but on the LPD type ships ? I think that's a distinct possibility.

Rahul M ji,

This is entirely possible in some joint Army - Navy sort of ops, but it would be mission specific only, I guess.

Kartik · Post by **Kartik** » 30 Mar 2010 23:59

chetak wrote:
Guys,

It's still very much a work in progress and it has an extremely long way to go before it arrives somewhere near its final form and shape.

Hope that they keep it simple and sturdy and not mess it up by attempting to do too much while trying to please too many people.

Chetak, I have no other gripes with the design as such..there are some that have been cribbing about the landing gear and all that whereas I can see that its fine as is. My only issue is that maybe on the rear seater's side, the glass canopy can be shortened right upto the rear seater's elbow, giving it a stepped look. the essential purpose is simply so that they can put a armoured panel out there, protecting the rear seater more.

Rahul M · Post by **Rahul M** » 31 Mar 2010 00:07

chetak wrote:
Rahul M wrote: not on the destroyers or frigates but on the LPD type ships ? I think that's a distinct possibility.
Rahul M ji,

This is entirely possible in some joint Army - Navy sort of ops, but it would be mission specific only, I guess.

right, since we don't have a dedicated combined arms marine force like the USMC. as and when army formations get permanently earmarked for amphib operations along with induction of the required amphibs, it's likely that organic attack helo assets will form a part of it. but yes, you are correct that those won't be operated by the navy.

chetak · Post by **chetak** » 31 Mar 2010 00:08

Rahul M wrote:well, if naval chetak says naval chetak with LMG is improbable who am I to argue with that ?

Rahul M ji,

Not improbable but highly possible and proven too.

In one of the ops, a Seaking Commando version was modified with an in house developed mounting incorporating a LMG, firing out the side doors.

The size and weight of this contraption was eminently suitable for installation on a Chetak and was tried out too as a backup.

The drawings are still around and the job could easily be done in a jiffy.

Rahul M · Post by **Rahul M** » 31 Mar 2010 00:11

ah thanks for the info. pardon for the OT but do you have any idea if we are going to replace the 42C anytime soon ? and with what ? the RFI is for ASW choppers only IIRC.

Sagar G · Post by **Sagar G** » 31 Mar 2010 00:15

Awesome atlast the D-Day arrived

rohitvats · Post by **rohitvats** » 31 Mar 2010 00:20

As for the deployment of LCH, I remember reading an article many moons ago in print media. It spoke about the concentration of heavy gunships with Strike Corps while LCH will be with other holding corps.

I hope we provide at least one Squadron of LCH for each of the Corps on Westerm border(plains), apart from Strike Corps, we'd need 5 Squadron worth of these. Order for 114 roughly translates into 5 Squadrons@22 LCH/Squadron. Let us see how these get distributed.

chetak · Post by **chetak** » 31 Mar 2010 00:24

Kartik wrote: Chetak, I have no other gripes with the design as such..there are some that have been cribbing about the landing gear and all that whereas I can see that its fine as is. My only issue is that maybe on the rear seater's side, the glass canopy can be shortened right upto the rear seater's elbow, giving it a stepped look. the essential purpose is simply so that they can put a armoured panel out there, protecting the rear seater more.

Kartik ji,

Right now the rear seat is occupied by the second pilot.

CTP Unni Pillai flew from the front and Hari Nair manned the dual controls installed in the rear cockpit. It will continue like this for quite some time until most of the tests flights have been completed and the flight envelope has been investigated to everyones' satisfaction.

Eventually the rear cockpit will make way for the weapons operator.

That is when the real attack helo characteristics will start to appear.

chetak · Post by **chetak** » 31 Mar 2010 00:27

Rahul M wrote:ah thanks for the info. pardon for the OT but do you have any idea if we are going to replace the 42C anytime soon ? and with what ? the RFI is for ASW choppers only IIRC.

Rahul M ji,

AFAIK, the 42Cs have a fair bit of life left in them yet.

But will anyway check and see.

Bob V · Post by **Bob V** » 31 Mar 2010 00:35

but the weapons operator occupies the front seat in most cases.

Rahul M · Post by **Rahul M** » 31 Mar 2010 00:35

rohit, AAC squadrons are usually smaller aren't they ? @ 10/sqdn IIRC ? even IAF helo sqdns have smaller # of airframes than their fighter counterparts which top it at 16/sqdn.

right now we have only 2 attack helo sqdns to go around for the 3 strike corps. I'm hoping at least the XIV corp gets one sqdn. the holding corps/IBGs will be supplemented by a significant number of the WSI-Dhruvs which will be churned out in the meantime.

rohitvats · Post by **rohitvats** » 31 Mar 2010 00:59

Rahul M wrote:rohit, AAC squadrons are usually smaller aren't they ? @ 10/sqdn IIRC ? even IAF helo sqdns have smaller # of airframes than their fighter counterparts which top it at 16/sqdn.

right now we have only 2 attack helo sqdns to go around for the 3 strike corps. I'm hoping at least the XIV corp gets one sqdn. the holding corps/IBGs will be supplemented by a significant number of the WSI-Dhruvs which will be churned out in the meantime.

Sir, if memory serves right, AAC Squadron has 15 helo/squadron. Basically, 3 Flights of 4+1 helos each. These are alloted at Corp HQ level and flights are detailed for the divisions under the Orbat of Corps.

As for requirment, even if we authorize one Sqn./Corps (apart from Strike Corps), we'd need 10 Squadron worth of these which @ 15 helos/Sqn. means 150 birds. BTW, 114 helos@15 per Sqn. will be 7 Squadrons and some change (may be trg.). But the numbers that I have given are for Cheetah/Chetak Sqn. and may be apply to ALH as well ( I don't see why it should not). Not sure, how the IA spreads out these birds per Squadron wise.

sunny y · Post by **sunny y** » 31 Mar 2010 01:05

Rahul M wrote: sensor wise, no it will not have a radar, few attack helos have one but otherwise it will a full spectrum of state-of-the-art sensors, ECM and a MAWS as well. even a DIRCM is in the works !

Help Gurus...I have few queries :

1) As per my knowledge HAL has signed a contract with Israel for LCH avionics. Is this an interim measure or are we thinking of equipping the whole fleet with their avionics ?

2) Is This DIRCM indigenous or imported ??

3) http://www.tribuneindia.com/2009/20091207/nation.htm#14
According to this article HAL is in talks with DRDO for indigenous MAWS for LCH....Any idea where are we currently with this ??

Thanks

Nihat · Post by **Nihat** » 31 Mar 2010 01:13

looking at this beauty fly today makes me wonder how much this would have helped us 11 years back in Kargil. We could have wrapped up Operation Vijay in half the time and saved the lives of so many Jawans.

Dhanush · Post by **Dhanush** » 31 Mar 2010 01:46

I am actually getting addicted to watching these two photos again and again. A jingo's heart is overflowing with pride.

Muns · Post by **Muns** » 31 Mar 2010 01:53

Just to mention from Ajai Shukla's Business Standard article :

159 Dhruvs and 76 WSI Dhruvs on order.

76 WSI dhruv + (114 Army + 65 IAF) LCH = 255 attack heli's on order.

This excludes the 22 heavy attack heli's to be ordered.

Note also I read the 80 Mi -17 IV on order are basically the gunship version

25 upgraded Mi-35's which i expect will run till around 2016.

Thats a LOT of Heli Firepower! (approx 382)

Any ideas on how many WSI dhruvs may be serving already?

http://www.bharat-rakshak.com/IAF/Aircr ... anshu.html
http://www.business-standard.com/india/ ... on/333870/

Kartik · Post by **Kartik** » 31 Mar 2010 01:56

Bob V wrote:but the weapons operator occupies the front seat in most cases.

Not in the Eurocopter Tiger. It too has the pilot in the front seat and the gunner in the rear.

Craig Alpert · Post by **Craig Alpert** » 31 Mar 2010 02:02

This is pertinent to those in the know. I've been on heli's before but have never been in a (LCH type heli) (2 pilot attack heli in other words..) Might be a retarded question but, are those seats Ejectable?? Can the pilots EJECT from those seats, or they have to go down with their priced possession? Please excuse me if this question seemed a lil out of place in a forum like ours!

PS. I know flying along 18,000 ft, the pilot can eject safely in a jet, don't know if the same can/can't be done in a Heli.. Hope someone can answer this for me and not make me feel stupid! Cheers!

negi · Post by **negi** » 31 Mar 2010 02:06

Afaik none of the modern attack choppers in service have ejection seats , the rotor comes in the way . Iirc there were some prototypes tested with rotors with expendable blades (using explosive bolts on the hub ) .

Anurag · Post by **Anurag** » 31 Mar 2010 02:11

The Kamov Ka-40 is currently the only gunship in production with ejection seats. The main rotors are equipped with some type of explosive bolts and disintegrate moments before the seat rocket is fired!

I doubt with the LCH has this built it..but I dont' know.

Kartik · Post by **Kartik** » 31 Mar 2010 02:12

chetak wrote: Kartik ji,

Right now the rear seat is occupied by the second pilot.

CTP Unni Pillai flew from the front and Hari Nair manned the dual controls installed in the rear cockpit. It will continue like this for quite some time until most of the tests flights have been completed and the flight envelope has been investigated to everyones' satisfaction.

Eventually the rear cockpit will make way for the weapons operator.

That is when the real attack helo characteristics will start to appear.

Chetakji I was saying not questioning who was in the front seat and I do realise that its only the beginning of its flight test program and its only a prototype as of now and changes can be made..I was simply saying that as of now, the canopy is too large..My gripe is exactly the opposite of Philip's, who complains that the gunner has poor visibility (important part is that the pilot has great visibility up front). A comparison with other attack helos will reveal that others have even more visibility restrictions..for instance if one looks at how restricted both the pilot's and gunner's view is in a Mi-28N which has heavy armour protection up front..

I feel that the gunner's seat is too exposed, what with small arms fire being the biggest threat to attack helos in COIN or other such anti-infantry roles, it is prudent to reduce the side bullet-proof glass canopy and instead have armoured composite panels right upto the gunner's elbow level. That will still give more than adequate visibility to the gunner on the sides while protecting him from bullets fired from below. the same can be said of the quarter glass panel next to the instrument dashboard right up at the front of the LCH, although it gives the pilot good view in the front quarter, so it may still be useful.

PratikDas · Post by **PratikDas** » 31 Mar 2010 02:23

I like the size of the panel displays in the instrument panel!

IT guys are going to have a field day

(All that space! OMG OMG OMG)

http://3.bp.blogspot.com/_o_no4M2xEPY/S ... Flight.jpg