LCH and other Helicopters Discussion Thread

abhik · Post by **abhik** » 13 Nov 2014 08:00

March 2016 induction would likely mean that the LCH would be inducted before the the Apache(where the contract is yet to be signed). Another reason to cancel the Apache deal.

PratikDas · Post by **PratikDas** » 13 Nov 2014 09:17

Anantha Krishnan M
‏@writetake
#BreakingNews LCH TD3 airborne on maiden flight. Now flying over Hoskote with Dhruv as chase.

The business end of a LCH.

shaun · Post by **shaun** » 13 Nov 2014 09:35

some grainy pictures coming

pragnya · Post by **pragnya** » 13 Nov 2014 11:09

srai wrote:I don't know why Mi-17s were not licensed produced in India?

they may just want to stick with assembly of MI 17V5 for the time being as HAL might take up the IMRH 'sooner' than later, with Modi's pitch for 'make in india' - being the order of the day - hopefully!!

vina · Post by **vina** » 13 Nov 2014 12:22

Dunno why , but I think the LCH seems to have a fat fuselage. With the Mi24 /Mi35, it can be justified as they carry troops as well. But for a pure attack heli , you don't need that fuselage depth. Looks like HAL just flattened out the sides of the Dhruv to that of a stepped tandem cockpit and really didn't do too much other arrangement. The engines positioning etc looks the same as Dhruv/ALH.

Oh well, as long as it flies well and does it's job. Many ways to skin a cat I suppose. Well, they can probably have bombs/missiles carried internally in the fuselage and deploy it in the plains as well!

srai · Post by **srai** » 13 Nov 2014 12:40

vina wrote:Dunno why , but I think the LCH seems to have a fat fuselage. With the Mi24 /Mi35, it can be justified as they carry troops as well. But for a pure attack heli , you don't need that fuselage depth. Looks like HAL just flattened out the sides of the Dhruv to that of a stepped tandem cockpit and really didn't do too much other arrangement. The engines positioning etc looks the same as Dhruv/ALH.

Oh well, as long as it flies well and does it's job. Many ways to skin a cat I suppose. Well, they can probably have bombs/missiles carried internally in the fuselage and deploy it in the plains as well!

This is Rudra's cabin:

Kartik · Post by **Kartik** » 13 Nov 2014 12:47

vina wrote:Dunno why , but I think the LCH seems to have a fat fuselage. With the Mi24 /Mi35, it can be justified as they carry troops as well. But for a pure attack heli , you don't need that fuselage depth. Looks like HAL just flattened out the sides of the Dhruv to that of a stepped tandem cockpit and really didn't do too much other arrangement. The engines positioning etc looks the same as Dhruv/ALH.

Oh well, as long as it flies well and does it's job. Many ways to skin a cat I suppose. Well, they can probably have bombs/missiles carried internally in the fuselage and deploy it in the plains as well!

i guess its because the LCH's cross section is really narrow..the depth is required to be able to carry a good fuel load and for systems.

Indranil · Post by **Indranil** » 13 Nov 2014 13:30

vina wrote:Dunno why , but I think the LCH seems to have a fat fuselage. With the Mi24 /Mi35, it can be justified as they carry troops as well. But for a pure attack heli , you don't need that fuselage depth. Looks like HAL just flattened out the sides of the Dhruv to that of a stepped tandem cockpit and really didn't do too much other arrangement. The engines positioning etc looks the same as Dhruv/ALH.

Oh well, as long as it flies well and does it's job. Many ways to skin a cat I suppose. Well, they can probably have bombs/missiles carried internally in the fuselage and deploy it in the plains as well!

The fuselage is chock-a-block full:

The tail boom is mostly empty, but then they can't make that part shorter because the main rotor is near the CG and the there has to be suitable clearance with the tail rotor. The main rotor of LCH has one of the largest diameters in its class ( and you know the reason for that).

Singha · Post by **Singha** » 13 Nov 2014 16:05

Hot n high fuel burn is surely higher too.
Maybe later we would see ah64 style cheek bays for extra ammo of the cannon and cmds.

shiv · Post by **shiv** » 13 Nov 2014 16:46

PratikDas wrote:
Anantha Krishnan M
‏@writetake
#BreakingNews LCH TD3 airborne on maiden flight. Now flying over Hoskote with Dhruv as chase.

The business end of a LCH.

Seen head on from 500 meters away - low over the trees there is very little there to aim at for a gunner. Even at the "bulbous" engine part the width is about 3.5 times a man's shoulders (you can guesstimate the pilot's shoulders there). But at 500 meters he has already finished shooting at you.

Indranil · Post by **Indranil** » 13 Nov 2014 23:50

Livefist has wonderful pictures. Click for higher resolution.

JTull · Post by **JTull** » 14 Nov 2014 00:07

The new lifting wing is much wider now. Very nice pictures, esp, the one showing bottom aspect.

rgsrini · Post by **rgsrini** » 14 Nov 2014 06:11

Ultra Secret combat helicopter from Pakistan

I hope the forum-ites haven't forgotten the super secret Pakistani combat helicopter, that can even take off and land on water. What impresses me most is that they seem to have solved the problem of "roomy cockpit" already, while actually providing superior visibility to the pilot.

shiv · Post by **shiv** » 14 Nov 2014 07:15

IIRC the LCH wing was originally rhomboidal in cross section. It is an aerofoil now.

Singha · Post by **Singha** » 14 Nov 2014 07:17

in WW2 some of the U-boats had a tethered thing like that to go up and spot things.

LCH does have a unusually broad rotor blade from near the roots itself.

shaun · Post by **shaun** » 14 Nov 2014 08:04

rgsrini wrote:Ultra Secret combat helicopter from Pakistan

I hope the forum-ites haven't forgotten the super secret Pakistani combat helicopter, that can even take off and land on water. What impresses me most is that they seem to have solved the problem of "roomy cockpit" already, while actually providing superior visibility to the pilot.

you made my day !!!

Hafeez sayeed will place huge orders for this one.... For his suicide bombers

member_24684 · Post by **member_24684** » 14 Nov 2014 08:36

.

is there any Plans for Maritime LCH to be Operated from future LHD/LPD for Some fire works against Small/speed Boat aggressors

prabhug · Post by **prabhug** » 14 Nov 2014 10:13

Is there any change in the tail wing ?

patel · Post by **patel** » 14 Nov 2014 11:12

Grainy video of LCH - TD3 first flight

Indranil · Post by **Indranil** » 14 Nov 2014 11:36

Writetake reports:

dinesha · Post by **dinesha** » 14 Nov 2014 15:39

member_20453 · Post by **member_20453** » 14 Nov 2014 17:17

Kalki LAH looking badass

Gagan · Post by **Gagan** » 14 Nov 2014 18:04

Dinesha re arrange the pics

rgsrini · Post by **rgsrini** » 14 Nov 2014 18:13

^^Dinesha,
Thanks for posting the side images. Even though the mirror image of TD2 is posted above, quite a few changes like the position of the wing, changes to exhaust, window armor, changes to the window geometry/angles (from //// to /\/\)and the rear wheel fairing/cowling can be compared easily.

I also read somewhere that the door opens sideways now. If you look closely you can see the hinges clearly. The close up pictures posted earlier, shows that even more clearly.

chiru · Post by **chiru** » 14 Nov 2014 18:30

the new td-3 has definitely undergone a nose job, it looks thinner between the windshield and the optronics ball

Raveen · Post by **Raveen** » 14 Nov 2014 18:43

Still too much glass area - spl in the vertical, they don't need that much headroom

Also not sure about the boxy surround for the rear suspension - doesn't look very aero shaped, appears to be draggier than the strut only solution.

member_28840 · Post by **member_28840** » 14 Nov 2014 19:14

patel wrote:Grainy video of LCH - TD3 first flight

thanks for sharing the video. worth watching.

despite other stealth characteristics such as faceted shaping and infrared suppression of exhaust, it is still one noisy bird.

can any guru shed some light on why a conventional tail rotor was chosen rather than a ducted tail rotor (or maybe even a NOTAR) which are significantly quieter and also offer some performance benefits.

sattili · Post by **sattili** » 14 Nov 2014 19:28

^^^^^
Can you tell us what performance benefits that the other two types of tail arrangement have over the current conventional one? And which currently operational attack helicopter sports either of these two types?

Thakur_B · Post by **Thakur_B** » 14 Nov 2014 19:28

shravanp · Post by **shravanp** » 14 Nov 2014 19:52

What a beauty.

shravanp · Post by **shravanp** » 14 Nov 2014 19:56

Would it had been an overkill to have retractable landing gears?

Singha · Post by **Singha** » 14 Nov 2014 19:59

Xave, I think NOTAR is history - a discredited sickular if you will.
regarding fenestron ducted
from wiki:
The Fenestron's disadvantages are those common to all ducted fans when compared to propellers. They include:
An increase in weight, power requirement and air resistance brought by the enclosure;
Higher construction and purchasing cost.

-
weight, reserve power and fuel consumption is a big thing for LCH due to our hot n high ops.

Cosmo_R · Post by **Cosmo_R** » 14 Nov 2014 20:00

skekatpuray wrote:Would it had been an overkill to have retractable landing gears?

It's a triumph of substance over form. I had the same question but I think the answer would be: "fewer moving parts"

member_28840 · Post by **member_28840** » 14 Nov 2014 20:09

sattili wrote:^^^^^
Can you tell us what performance benefits that the other two types of tail arrangement have over the current conventional one? And which currently operational attack helicopter sports either of these two types?

i cant determine if you are being sarcastic or not.

The RAH-66 Comanche, which was the only stealth attack / scout helicopter designed so far, used ducted fans. As far as i am aware no "currently operational" attack helicopters use these types. however there could be other reasons for this , than to simply say attack helicopters should only have conventional tail rotors.

from wiki

Advantages

Increased safety for people on the ground, the enclosure provides peripheral protection;
Greatly reduced noise and vibration, due to the enclosure of the blade tips and the greater number of blades;
A lower susceptibility to foreign object damage, as the enclosure makes it less likely to suck in loose objects such as small rocks
Enhanced anti-torque control efficiency.

A computational simulation has suggested that maximum achievable thrust is twice as high, and that at identical power, thrust was slightly greater, than for a conventional rotor of the same diameter.

even though safety, efficiency, etc are nice , my main concern is the noise

as the soviets found out in Afghanistan and the Americans in the attack on Karbala , the attack helicopters main enemy are SAMs and to a lesser extent ground fire.

Radar stealth while useful , is not much use against an infantryman in a foxhole with MANPAD.
IR Suppression is great against older gen IR missiles. I am sure the ANZAs the baki's have cannot hit the side of a barn door, but what happens when the Chinese start delivering newer types with better (stolen) tech ?

The key in battle is to strike before the enemy knows you are there, and accurate firecontrol and long range weapons are useful for that. However when you are flying in at treetop level you wouldn't have much range for your sensors and can be ambushed, especially if you are making a lot of noise which lets your enemy know which direction you are coming from and where to aim at before you can see him.

apologizes for the rant, but going back to my original question, does anyone know why conventional tail was chosen?

edit: thanks singha, i suspected as much.

VijayN · Post by **VijayN** » 14 Nov 2014 20:13

rgsrini wrote: I also read somewhere that the door opens sideways now. If you look closely you can see the hinges clearly. The close up pictures posted earlier, shows that even more clearly.

Here is a closeup of the doors (Tarmak007), was curious though. Are the doors a bit old fashioned? Just visually comparing with other western/russian birds, which seem to open bottom up, etc. A sharp sniper can aim for these hinges, I could be wrong though.

member_28840 · Post by **member_28840** » 14 Nov 2014 20:16

maybe the doors were chosen for ease of production rather than anything else? there will probably be more changes before FOC version.

Singha · Post by **Singha** » 14 Nov 2014 20:19

the dhruvs have a whispery quiet noise because some anti-vibration system from 'lords aviation' has been fitted.
perhaps it will be tried on LCH as well once the airframe, final choice of materials and hence vibration behaviour is frozen.
on dhruv it was fitted around 10 yrs after the 1st flight when the volume production was nearly about to commence

http://www.lord.com/products-and-soluti ... otary-wing
http://www.lord.com/products-and-soluti ... nd-defense

that close up photo shows the huge headroom in front cockpit and possibility of a stepped windscreen as in other attack helos if desired ...

Karan M · Post by **Karan M** » 14 Nov 2014 20:23

would like to see the sniper who can hit the moving chopper let alone the hinges

member_28840 · Post by **member_28840** » 14 Nov 2014 21:13

@singha

i didnt know about the quietening of dhruv. i did always wonder about the whispering sound made by the rotors. thanks for sharing.

Indranil · Post by **Indranil** » 14 Nov 2014 21:51

@Xave
Development of Fenestrons for Dhruvs is in the pipeline. I don't know if the same will be adopted to LCH. There are pros and cons.

@VijayN, Xave
Those hinges are a result of lot of feedback. It has got nothing to do with old-fashioned, ease of manufacture etc. In TD1, the door were hinged at the top and very new-fashioned.

The sideways hinged door is a result of the weight reduction process from TD1 to TD2, and feedback from the test pilots on ease of ingress and egress.

Then from TD2 to TD3, these hinges provide better sturdiness. But taking aim at those hinges

. Why? There are much bigger and more vulnerable areas of a helicopter.

@skekatpuray
They had very stringent requirements on the crash-worthiness of the aircraft. Going for a retractable gear would have greatly complicated the design and added to weight. If they want to reduce drag, they can go for wheel skirts and fairings.

@Raveen
Why would they put a fairing if it is draggier than what they surround?