LCH and other Helicopters Discussion Thread

nikhil_p · Post by **nikhil_p** » 29 Jun 2011 22:42

As Rakesh mentioned it does not matter whether you are doing 275 or 400 if a SAM is launched at you. What matters is the agility of the helo. Also, a chopper will not be flying at max speed when attacking as it will not be very stable. Also the max speeds are achieved not with the chopper in horizontal plane but a nose down profile, which makes attack difficult.

Another factor would be that a chopper flying at 275 will hypothetically give a window of 2 mins and 3 seconds for a 5KM range of vision and typical shoulder launched SAM range. If you factor in the reaction time of say 30 seconds so you have a 1 min 33 second window.
Same window for a speed of 300 will be 1 min 30 secs, for 350 will be 1 min 25 secs.

In war time however this will reduce due to the pop up capability of the chopper. Agility will play a large part, speed wont.

And yes the window will be even smaller for guns.

Rahul M · Post by **Rahul M** » 29 Jun 2011 22:47

nikhil, best check the replies on this topic (cockpit glass) by Gp Capt Hari Nair in the earlier pages of the thread, much better than hearing from us armchair pilots.

Surya · Post by **Surya** » 29 Jun 2011 23:14

The speed matters if you do not excpect or know where the helo comes from and reduces the window to acquire the target

There was an article on US exercises using Hinds which had the straightline speed to do just that.

Of course the weakness of the hind was in other areas

So its all a trade off and I am sure the designers took into account all that

John · Post by **John** » 29 Jun 2011 23:33

Yeap speed is mainly important in urban warfare (where range is not as critical) when helos have to fly lo and fast to reduce their transit time (for fire support mission like recent Kabul hotel incident) and detection range/engagement window.

Fyi that chart isn't accurate KA-50/52 doesn't have 1k Km range think they confused ferry range with combat radius and range for different chopper. Not sure how accurate the top operational speeds are either.

Kartik · Post by **Kartik** » 29 Jun 2011 23:43

nikhilarora wrote:Hi,

I am sure this has been discussed here before but would want to ask again! The LCH TD2 has a generous glass area in the cockpit as was in TD1, wont it come under heavy small arms fire and compromise the safety of the crew? Can the gurus please elucidate!

Wng Cmdr (Retd) Hari Nair of HAL, one of the LCH's test pilots was active in the discussions on BRF earlier. He did mention that the TD's were just that- technology demonstrators. As more feedback would be given to the HAL designers by the TP's and others, there would be changes to the design.

I had mentioned to him that the canopy seemed quite large on the LCH compared to other helis and he pointed to the Apache's prototype- it had a larger canopy than the production variant did. I assume that meant that its possible that the production LCH may feature a smaller canopy for crew protection, to reduce exposure to small arms fire. May well be a question of reducing weight elsewhere so more can be put into armour near the cockpit canopy area.

Shrinivasan · Post by **Shrinivasan** » 30 Jun 2011 00:23

abhishek-nayak wrote:ALL is good But here is a thing to worry about.According to graphics the service ceiling of LCH is same as that Of apache but the speed is much slower.Infact LCH is the slowest of all the attack helicopters.For a heli like LCH the max speed should be more than 300 km/hr

Speed is a factor of payload, range and loiter time.... LCH has been deigned with Desi requirements... hopefully the goalpoast wont get shifted on the eve of induction.. fortunately in LCH's case, the services (IAF and IA) have already placed large orders for the beauty... we should name it Aishwarya....

Shrinivasan · Post by **Shrinivasan** » 30 Jun 2011 00:25

I take back the suggestion of Aishwarya, Kareena is a more appropriate name for it svelte figure.. deadly looks tooo

Rakesh · Post by **Rakesh** » 30 Jun 2011 01:06

The name Aishwariya is already taken for the Mirage 2000. Kareena it is.

Rakesh · Post by **Rakesh** » 30 Jun 2011 02:03

From Livefist --> Digital Cutaway of the LCH

http://twitpic.com/42l3gy

Prem · Post by **Prem** » 30 Jun 2011 02:10

Dazzling beauty can be named Menaka or Shalkuntala!

SaiK · Post by **SaiK** » 30 Jun 2011 02:20

is it not possible to extend the stub wing to add one more pylon on each side?

shiv · Post by **shiv** » 30 Jun 2011 05:37

Rakesh wrote:Craig: If someone is firing a shoulder launched missile against a low flying helicopter, would it make any difference if the top speed of the helicopter is 275+ km/h or 400+ km/h? Not asking a rhetorical question, just want to know...as you make an interesting point. As you suggest, they might increase the speed if the need arises.

I may be mistaken but there may be a current technological "upper limit" of speed for conventional helos (like LCH) around 300 kmph. I think the reason may have something to so with airflow going supersonic on the rotor bade that is moving forwards. Not sure though

SaiK · Post by **SaiK** » 30 Jun 2011 05:44

Infrared jammers, chaff & flare, retractable decoy pods are so suitable for helos against heat seeking missiles.

shiv · Post by **shiv** » 30 Jun 2011 06:31

SaiK wrote:Infrared jammers, chaff & flare, retractable decoy pods are so suitable for helos against heat seeking missiles.

True - and there are other factors. Helos use terrain cover and flying even at 200 kmph they can whiz past hostile installations without anyone getting a chance to get a bead on them. The helo will have gone past a clearing in trees or between buildings like a car doing 200 kph going past your gate while you wait with a gun to get a shot.

In the open - the helo will appear low over the horizon at distances of 1000 or more meters and will be shooting at you and not waiting for you to get a bead and shoot back. If the helo flies well over your lines so that your people are all around - i.e front, back and sides - the helo can get hit - the pilots have to have some idea of where they are going and what they are doing. In a networked environment there may be a ground controller or a UAV that has located specific targets to be taken out by the helo - which will be attacked by keeping the helo in a position where it is least likely to take a small arms or manpad hit.

Virupaksha · Post by **Virupaksha** » 30 Jun 2011 07:16

Also the top speed is very difficult to achieve in a battle.

the last speed, i.e. 250 kmph + to top speed is going to take hell lot of time and at these top speeds, the helicopter will not be able to maneuvre, so basically, you have to flying at a decent height to avoid hills and trees. Which means the heli is a much easier target than when it is moving at 150-200 kmph but can maneuvre to hide behind hills and trees and make the missile waste its energy. So top speed will lead to presenting a nice juicy target high up in the air, moving in a constant direction.

For a heat seeking missile, choose between a target up in the air moving in a constant direction vs a target moving in a relatively slower speed but with abilities to maneuvre and hide in land clutter.

SaiK · Post by **SaiK** » 30 Jun 2011 08:03

yup.. very vulnerable for close combats.. as shiv says, delivering top attack nags & other bombs from +1kms at the least is an ideal plan when the enemy zone is not sanitized.

Shrinivasan · Post by **Shrinivasan** » 30 Jun 2011 10:56

Prem wrote:Dazzling beauty can be named Menaka or Shalkuntala!

naaw... this svelte Sizzling deadly beauty is indeed Kareena.

neerajb · Post by **neerajb** » 30 Jun 2011 12:47

Curise speed v/s hover efficiency depends upon disc loading. Following is the disc loading of helicopters at max takeoff and at hover:

Code: Select all

eurocopter : 45.187 Kg/m2
AW-129 : 41.34 Kg/m2
Super Cobra : 50.095 Kg/m2
Apache : 62.038 Kg/m2
Ka-50/52 : 32.68 Kg/m2
Mi-28N : 50.05 Kg/m2
LCH : 41.01 Kg/m2

It is evident that LCH has the lowest disc loading after Ka-50/52 which is comparatively heavier helicopter. Lower disc loading means lesser power required for hover and hence more efficient at hovering (better high altitude permformance margins) but lower disc loading also means lesser speed. LCH is optimised for high altitude and thus designed like that and it is not a deficiency. Propellers of fixed wing aircrafts have much higher disc loading which is required for high cruise speeds with less drag. So it's basically hover v/s cruise speed and LCH opted for former.

Cheers....

Singha · Post by **Singha** » 30 Jun 2011 13:04

a logo like this on each machine would be good.
http://stocklogos.com/sites/default/fil ... e_1292.png

jamwal · Post by **jamwal** » 30 Jun 2011 13:53

Shrinivasan wrote:this svelte Sizzling deadly beauty is indeed Kareena.

Couldn't have picked a worse name.

pralay · Post by **pralay** » 30 Jun 2011 14:22

neerajb wrote: Lower disc loading means lesser power required for hover and hence more efficient at hovering (better high altitude permformance margins) but lower disc loading also means lesser speed.

Regarding the unit of disc-loading, the Kg/m2... does it indicate the span of rotorblades?
in other terms,
can LCH achieve better speed with lesser length of rotor-blades?

Vikram W · Post by **Vikram W** » 30 Jun 2011 14:46

Shrinivasan wrote:
Prem wrote:Dazzling beauty can be named Menaka or Shalkuntala!
naaw... this svelte Sizzling deadly beauty is indeed Kareena.

Are you trying to say the LCH looks like a horseface ?

bmallick · Post by **bmallick** » 30 Jun 2011 15:01

sameer_shelavale wrote:Regarding the unit of disc-loading, the Kg/m2... does it indicate the span of rotorblades?
in other terms,can LCH achieve better speed with lesser length of rotor-blades?

Disc - Loading = Weight / total main rotor disc area

Please read this for gaining more information. http://en.wikipedia.org/wiki/Disk_loading . Also in future please try to read around a bit yourself so that your overall knowledge increases.

Please note that LCH is optimised for High Altitude performance, hence the lower disc-loading so that it can hover in the thin air high in the mountains. This means that LCH can pull its self around in the rarified air in the mountains and probably beat others in actual speed at those altitude. When others would be gasping to catch air, LCH would simple breeze through.

Air speed is a design thing. Simply doing one thing would not increase your air speed. The faster we go the more is the chances of "Retreating Blade Stall" and "Airflow Reversal", both of which can result in decrease in the lift that is being produced. So simply improving speed would mean it starts effecting things elsewhere. Everything effects each other, hence you design balancing your features against the requirements.

So rather than blindly thinking that Fast is Furious, lets close our eyes and harness the power of kundalini/chi.

bmallick · Post by **bmallick** » 30 Jun 2011 15:06

Vikram W wrote:
Shrinivasan wrote: naaw... this svelte Sizzling deadly beauty is indeed Kareena.
Are you trying to say the LCH looks like a horseface ?

Vikram, beauty lies in the eyes of the beholder. Some like their horses and others an ass (no pun intended )

Mahendra · Post by **Mahendra** » 01 Jul 2011 02:13

Why Katrina? because the engine is furrin?

Singha · Post by **Singha** » 01 Jul 2011 09:43

kareena sir, not katrina.

vishnu.nv · Post by **vishnu.nv** » 01 Jul 2011 19:52

Still no pics of kareena in digital camouflage ???

Shrinivasan · Post by **Shrinivasan** » 02 Jul 2011 00:44

vishnu.nv wrote:Still no pics of kareena in digital camouflage ???

Jingos are waiting with bated breath.... we are all still salivating over AI2011 pictures.. where are chaiwaallas and Paanwaals when we need them!!!

VishalJ · Post by **VishalJ** » 02 Jul 2011 04:42

Shrinivasan wrote:
vishnu.nv wrote:Still no pics of kareena in digital camouflage ???
Jingos are waiting with bated breath.... we are all still salivating over AI2011 pictures.. where are chaiwaallas and Paanwaals when we need them!!!

Well i have a nice shot of ZP4602, while it is from AI2011, to me - it looks quite fab.
I'll edit it & put-it-up soon, you can checkout these shots of ZP4601 in the meanwhile if you may.

I have to admit that i sinned by not really going after the LCH in the 2~3 days i had with it at AI, it had that unfortunate snag & had to fly back to HAL on (IIRC) the evening of February 10th 2011, Damn!

disha · Post by **disha** » 02 Jul 2011 05:17

vishnu.nv wrote:Still no pics of kareena in digital camouflage ???

There was one for the outer body shell posted just around AeroIndia this year, should be in one of the AI photo archives. Jingoes are using that poster instead of real Kareena.

Saar. Why do not you do a segment on LCH? You should have access - no?

nachiket · Post by **nachiket** » 02 Jul 2011 07:59

^^I think you are confusing him with another Vishnu.

Shrinivasan · Post by **Shrinivasan** » 02 Jul 2011 10:44

disha wrote:
vishnu.nv wrote:Still no pics of kareena in digital camouflage ???
There was one for the outer body shell posted just around AeroIndia this year, should be in one of the AI photo archives. Jingoes are using that poster instead of real Kareena.

Saar. Why do not you do a segment on LCH? You should have access - no?

this Vishnu is not Vishnu Som of NDTV?!?!?

vishnu.nv · Post by **vishnu.nv** » 02 Jul 2011 10:57

disha,

I am not Vishnu Som of NDTV.

Vishal,

What i meant was pictures of First Flight.

Shrinivasan · Post by **Shrinivasan** » 02 Jul 2011 11:01

Where are the pictures of LCH AKA Kareena TD2 in flight... Shiv Saar, any luck from your Golf Course...any Chaiwaalas, Paanwaala, Bhel Puri Stall guy sources with even a Cell Phone image... hmmm.... uncle Google is also barren...

Shrinivasan · Post by **Shrinivasan** » 02 Jul 2011 11:07

Speculation Alert ON.
Is this LCH TD2, to my untrained eys, it looks similar to TD1. but the lack of any markings sort of throws me off...
Edited: Removed the wrong picture of LCH TD2.

Shrinivasan · Post by **Shrinivasan** » 02 Jul 2011 11:30

Marten wrote:
Shrinivasan wrote:Speculation Alert ON.
Is this LCH TD2, to my untrained eys, it looks similar to TD1. but the lack of any markings sort of throws me off...
http://cdn-www.airliners.net/aviation-p ... 307417.jpg
This is the Eurocopter Tiger: http://en.wikipedia.org/wiki/Eurocopter_Tiger

This is the page on Airliners: http://www.airliners.net/photo/France-- ... dd106b8c2f

Thanks Marten.. saw the difference... still no luck

VishalJ · Post by **VishalJ** » 02 Jul 2011 15:26

vishnu.nv wrote:Vishal,

What i meant was pictures of First Flight.

Oh Sorry !

When was the FF?

Bala Vignesh · Post by **Bala Vignesh** » 02 Jul 2011 15:43

Vishal Jolapara wrote: Oh Sorry !

When was the FF?

It was about 5 days back at around 1500 hrs..

Shrinivasan · Post by **Shrinivasan** » 03 Jul 2011 00:21

Bala Vignesh wrote:It was about 5 days back at around 1500 hrs..

I Promise a Treat for the first person to post a picture of this deadly beast in all her glory - TD2 flying during first test flight!!!

Bala Vignesh · Post by **Bala Vignesh** » 03 Jul 2011 01:31

Shrinivasan wrote:I Promise a Treat for the first person to post a picture of this deadly beast in all her glory - TD2 flying during first test flight!!!

That does it.. I am going camping on top of my old joint to see if i can spot this bird pop up for atleast some time.. Can someone here lend me a Canon telephoto zoom lens to capture this bird???