LCH and other Helicopters Discussion Thread

[Raveen]

After looking at the picture, would it be better to design retractable wheels and pods as to give more stealth characteristics?

Retractable undercarriages come with a large weight and complexity penalty (hydraulics, etc.) It will also reduce the survivability of the airframe as the gear will not be available to absorb forces in a crash. Clearly, the designers have concluded that the relatively low improvement in RCS is not worth the penalties.

More than RCS the trade off is with drag

[Raman]

(a) Drag was not the argument made by Hitesh, so I did not mention it.
(b) None of Apache, Mangusta, Rooivalk, Tigre, Havoc have retractable undercarriages. Clearly, top-end speed is not the end-goal, and the survivability concerns remain.

[PratikDas]

I don't think what's shown in the picture points to a retractable carriage as the only option. The plates could also just be there to reduce the directional RCS. The back of that casing could be completely open to allow the shock absorbers to move back on landing.

[Yagnasri]

looks like a camachi to me

[VinodTK]

India's first combat helicopter

HAL has solid orders of 65 LCHs for the Indian Air Force and an additional 114 for the Indian Army.

Performance: Maximum Speed: 148 knots or 171 miles per hour (mph); Cruising: 2140 knots or 161 mph. The LCH has a range of 700 km or 342 miles and with an operational ceiling of 21,300 feet.

The planned Weapons load is a Turret mounted 20mm Cannon, unguided rockets, air to air and air to surface missiles including Anti-tank and Anti-Radar missiles and unguided bombs, cluster bombs and grenade launchers.

With such an ordinance load the LCH is designed and equipment to carry out multiple missions. These include Anti-armor and anti-infantry attack. Air Defense against other helicopters

[Pratyush]

114+65= 179 machines combined for two services. It is a good number, add to this the tender for 22 medium attack helos, the Indian Armed forces will have at minimum of 201 attack helos by the 2025s.( I hope).

What I would like to see is a national Helo road map. for a 10 ton class helo.

This will be in the NH 90 / Bkackhawk Class. Whcih can be used as Naval helo as well as an army helo. Do this agressively, so that by 2020 ve are able to Start repalcing the older Mi8/17s. With a domestic product. This helo will also give us with the design and propulsive capabilities to design an MCH similar ti the the Mil 28 or the AH 64. Should the IA require a domestic MCH.

Also I would like to see a heavy lift helo in service with the armed forces in large nos by 2020s, in similar class as the Chinook. They need all the lift they can get.

[Dmurphy]

IMHO, we need Little Bird class of Helos with M134 Miniguns for low flying, search and destroy missions in Naxal areas. Spraying the hideouts with 7.62mms should get the rats out of their holes without harming the environment much. HAL's LOH/LUH can be customised into this variant. JMT

[Pratyush]

Lets have a roadmap of the Helo requirement till 2025 and beyond and what roals we expect the Helo to fill in the security forces niech.

I have already mentioned the kinds of helos that I would like to see manufactued in the country in my previous post on this thread. I request other members to contribute their Ideas WRT the Helos.

[Hari Nair]

PS: When you look down at Phase II residences (a short distance from the residences of some of the Heli division employees) and see folks wave at you from the terraces, please know that there is a small fan club that spends a fair part of the day admiring your team and its magnificent birds.

That's great, Marten! Its very inspiring to know we have keen aviation enthusiasts watching us. Which side of the helipad are you guys on - the western or the eastern side?

[Hari Nair]

Hari Sir, is this what we can expect in the future?

Note: Image name indicates this is a mockup

That was an old concept mock-up built as a static display for an airshow. The "future" is the LCH TD-1, which is already here and flying!

[Hari Nair]

IMHO, we need Little Bird class of Helos with M134 Miniguns for low flying, search and destroy missions in Naxal areas. Spraying the hideouts with 7.62mms should get the rats out of their holes without harming the environment much. HAL's LOH/LUH can be customised into this variant. JMT

Eco-friendly Rambos, eh?

[anand_sankar]

Mr Nair,

What do your service rules say about blogging about your daily life???

Ok, even if you can't write with your real name or mention real events in detail, can you write a blog like this one...

http://flightlevel390.blogspot.com/

This blog is written by an American commercial pilot who calls himself Capt Dave. I am a huge fan of this blog, it would be great if an Indian pilot defence/civil can write one like this.

[shiv]

PS: When you look down at Phase II residences (a short distance from the residences of some of the Heli division employees) and see folks wave at you from the terraces, please know that there is a small fan club that spends a fair part of the day admiring your team and its magnificent birds.

That's great, Marten! Its very inspiring to know we have keen aviation enthusiasts watching us. Which side of the helipad are you guys on - the western or the eastern side?

And don't forget me when you look down at the golf course

[rohitvats]

114 LCH for the IA - that is great news. If we assume 16 LCH per AAR unit (4 flights of 3 LCH+4 Reserves), we're looking at 6 Squadrons worth of LCH+training/conversion. These are going to be great assets with IA Corps.

[Hari Nair]

Thanks Hari Nair

regarding the silent blade, is this a fad or for real?
http://www.geekologie.com/2010/02/impre ... lent_h.php

On Naval vessels, can LCH cannon be used as an anti-torpedo CIWS?

Quoting from the Eurocopter press release of 22 Feb -

"Silencing main rotors and blades to protect the environment and extend service life
Eurocopter is pursuing several methods of optimizing main rotors to reduce external noise and cabin vibrations with the goal of introducing them as soon as feasible on the company’s helicopters. One way is to change the shape of the blade, using a technology called Blue Edge™. The other is to integrate “intelligent” piezoelectric actuators into the trailing edge of the blade with a technology designated Blue Pulse™. Both Blue Edge™ and Blue Pulse™ are displayed on Eurocopter’s booth at Heli-Expo.

Blue Edge™: This revolutionary main rotor blade provides a passive reduction in noise levels, using a double-swept shape that is very different from present-day blades. The aim of this program is to reduce the noise generated by so-called blade-vortex interactions (BVI), which occur when a blade impacts a vortex, created at the tip of the blade of any helicopter.

A five-blade Blue Edge™ main rotor has been flying since July 2007 on an EC155 testbed, logging 75 flight hours and demonstrating noise reductions of 3 to 4 dB, as well as very good performance of the blade. With this safe and simple means of measureable noise reduction for helicopters now validated, Eurocopter is ready to move Blue Edge™ into production applications.

Blue Pulse™: This piezo-active rotor control system has the primary objective of reducing noise levels generated by the interference of the rotor blade tip vortices from one rotor blade with the following blades. In addition, it will significantly reduce vibrations within the helicopter airframe, increasing passenger comfort and extending the service life of sensitive components,

The control system uses three flap modules located at the trailing edge of each rotor blade. The blades’ piezoelectric actuators move the rotor flaps 15 to 40 times per second in order to completely neutralize the “slap noise” typically associated with helicopters during descent. The Blue Pulse™ technology has been flying since 2005, showing a noise reduction of up to 5 dB. Eurocopter’s evaluations with Blue Pulse™ are continuing on an EC145, while the development of a miniaturized system for production applications is advanced."

Appears that the advantage is 3-4 db reduction for the production ready version 'Blue Edge' and another 5 db reduction for the as-of-yet experimental version 'Blue Pulse'. I guess any reduction in noise is welcome for civil applications, provided the cost-benefit ratio is favourable. I suppose they must also be grappling with failures mode analyses for the active 'Blue Pulse'.

From the Military point-of-view with a total of just about 9 db reduction (assuming both modes add up are compatible with each other), I wonder whether we are have arrived at the 'Whisper Mode' aka Blue Thunder style. Maybe not.

As I understand, the M621 single-barrel cannon is available for marine applications on small vessels, however, a CIWS against an incoming missile needs a very high rate of fire to be effective - which means a Gatling configuration. You mentioned 'against a torpedo' - that's an underwater weapon isn't it ? Perhaps you meant an anti-ship missile.

[Hari Nair]

Mr Nair,

What do your service rules say about blogging about your daily life???

Ok, even if you can't write with your real name or mention real events in detail, can you write a blog like this one...

http://flightlevel390.blogspot.com/

This blog is written by an American commercial pilot who calls himself Capt Dave. I am a huge fan of this blog, it would be great if an Indian pilot defence/civil can write one like this.

Anand,
I retired from the IAF and am an ex-serviceman!
I checked out the blog - he definitely writes well.
-That's a nice suggestion of yours to start my own blog - let's see ..

[negi]

Hari sir what are the blade loading numbers for the LCH (please ignore if these cannot be de-classified) ? Also are there any plans to mount laser dazzlers on the platform ?

[Raja Bose]

I retired from the IAF and am an ex-serviceman!

Sir, is that usually the case for test pilots who fly for HAL - both helo and fixed-wing? I thought at least for the fixed wing, the pilots are on deputation, no?

You have no idea how many admirers of the Sarang Team display there are, all around the world! It is by far the best helicopter display team in the world, bar none (and this is no mere jingoistic rhetoric).

Hope you can describe some of your Sarang experiences here

[Gaur]

Hari sir what are the blade loading numbers for the LCH (please ignore if these cannot be de-classified) ? Also are there any plans to mount laser dazzlers on the platform ?

Why would laser dazzlers be needed on an attack helicopter?

[Hari Nair]

And don't forget me when you look down at the golf course

How come some guys have all the luck playing golf during working hours!

[Hari Nair]

Hari sir what are the blade loading numbers for the LCH (please ignore if these cannot be de-classified) ?

Negi, you can calculate the disc & blade loading figures for yourself! All Up Weight (AUW) / Disc or Blade area. Will take about 2-3 min of your time.

[Bala Vignesh]

Hari sir, you were with the very first Sarang team, right?
Could you please tell us how you guys formulated all the manoeuvers for the display and how each member is allotted positions??

[vasu_ray]

From the Military point-of-view with a total of just about 9 db reduction (assuming both modes add up are compatible with each other), I wonder whether we are have arrived at the 'Whisper Mode' aka Blue Thunder style. Maybe not.

As I understand, the M621 single-barrel cannon is available for marine applications on small vessels, however, a CIWS against an incoming missile needs a very high rate of fire to be effective - which means a Gatling configuration. You mentioned 'against a torpedo' - that's an underwater weapon isn't it ? Perhaps you meant an anti-ship missile.

Thanks Hari Nair,

if the 9dB reduction in blade noise can be translated to reduced distance between insertion and targets, wouldn't that help? maybe its all dicey based on the surroundings like in hills vs. plains

on the CIWS, Here is a scenario,

IN has plans to carry helis on every one of its ships, the heli could be a 'NRURAV'

An IN ship detects the presence of a sub with its Sonar and sends the heli armed with an onboard torpedo to engage it

now the sub fires its own torpedo against the ship before it gets intercepted

IN ship is tracking this torpedo and it communicates with the heli effectively treating the chopper as a flying CIWS with the command and guidance being on a wireless path. The heli engages with its onboard gatling gun which can penetrate the water surface upto 10m in depth. The whole engagement is controlled by the ship's BMS and the heli is left on auto-pilot

the assumption here is the torpedo is closer to the water surface within 1-2 km of the ship

Now the LCH by design carries a gun, even if it doesn't go onto a Naval platform, they could apply the learning's to the naval choppers, the transition from a simple gun to an accurate gatling gun is a question of improving the fidelity of the system and perhaps the LCH can prove it for NRURAV

this was all before I learnt Adm. Gorshkov carries a anti-torpedo CIWS but smaller vessels can benefit if feasible

[koti]

A few points to be noted Vasu ji.

A Gatling gun gives immense recoil(Not 7.62mm Gatling configurations). A small helicopter can not handle that. And the 10m water penetration needs 23mm or 30mm rounds which will result in a very high weight and other complications. Added the sensors take up the payload capacity too.

So the NRURAV will be forced to become a dedicated ASW CIWS platform. This, I doubt would not be an option.

Instead, The URAV can just carry a few, remotely detonated depth charges. Cheap, less side effects, and effective.

They can be deployed by the aircraft at an appropriate distance to bang on the right time.


As far as the Vikrant(Lets call it by the new name) goes- The CIWS is a more sensible option as the torpedo has to approach the surface when near it target to cause any damage and thus is vulnerable to the CIWS. But the same need not be true when the torpedo is cruising towards the target.
All said, Naval Thread suits the discussion better from this point.

[Hari Nair]

From the Military point-of-view with a total of just about 9 db reduction (assuming both modes add up are compatible with each other), I wonder whether we are have arrived at the 'Whisper Mode' aka Blue Thunder style. Maybe not.

As I understand, the M621 single-barrel cannon is available for marine applications on small vessels, however, a CIWS against an incoming missile needs a very high rate of fire to be effective - which means a Gatling configuration. You mentioned 'against a torpedo' - that's an underwater weapon isn't it ? Perhaps you meant an anti-ship missile.

Thanks Hari Nair,

if the 9dB reduction in blade noise can be translated to reduced distance between insertion and targets, wouldn't that help? maybe its all dicey based on the surroundings like in hills vs. plains

on the CIWS, Here is a scenario,

IN has plans to carry helis on every one of its ships, the heli could be a 'NRURAV'

An IN ship detects the presence of a sub with its Sonar and sends the heli armed with an onboard torpedo to engage it

now the sub fires its own torpedo against the ship before it gets intercepted

IN ship is tracking this torpedo and it communicates with the heli effectively treating the chopper as a flying CIWS with the command and guidance being on a wireless path. The heli engages with its onboard gatling gun which can penetrate the water surface upto 10m in depth. The whole engagement is controlled by the ship's BMS and the heli is left on auto-pilot

the assumption here is the torpedo is closer to the water surface within 1-2 km of the ship

Now the LCH by design carries a gun, even if it doesn't go onto a Naval platform, they could apply the learning's to the naval choppers, the transition from a simple gun to an accurate gatling gun is a question of improving the fidelity of the system and perhaps the LCH can prove it for NRURAV

this was all before I learnt Adm. Gorshkov carries a anti-torpedo CIWS but smaller vessels can benefit if feasible

Interesting concept - using a rotary UCAV / Attack Helicopter as a remote CIWS platform for the mother ship!

As Koti just stated - its the recoil of the weapon that appears to be the first limit- since we need a cannon beefy enough to put out a whole lot of projectiles that can punch through 10 m depth of water and still do damage. That's assuming the sub's been detected in the first place long enough to launch and position the UCAV to the correct intercept point.

Re- the 9 db noise reduction - remember that's from the main rotor. The helicopter is actually about some 10,000+ parts flying in 'close formation', each putting out its own noise imprint. We really do need a 'Whisper Mode' breakthrough result before claiming the advantage of noise reduction. Also, that cannot come at the cost of high altitude performance, which is a very critical requirement for us.

[negi]

Hari sir what are the blade loading numbers for the LCH (please ignore if these cannot be de-classified) ?

Negi, you can calculate the disc & blade loading figures for yourself! All Up Weight (AUW) / Disc or Blade area. Will take about 2-3 min of your time.

Sir disc area and loading numbers are already out there, I could not find the blade area for LCH (need the chord width).

[Hari Nair]

@ Raja Bose & @ Bala Vignesh - Thanks for appreciating the IAF’s Sarang Team. At the very definite risk of going OT – the first team was directed to evolve on fast track by the then Chief of Air Staff - Air Chief Marshal Krishnaswamy (the concept of an ALH display team was his brainchild)– it was quite a bit of struggle since our early attempts at displays were awkward. We were under ASTE, AF (Bangalore) in those days and were lucky to have a nearby disused airstrip available to use extensively to evolve our pattern, with ASTE’s resources and an understanding Commandant. IAF’s SKAT (Surya Kiran Aerobatic Team) helped us with some very critical insights into display flying. That, coupled with some very patient and good encouragement by key senior IAF officers made it possible. The pilots were hand-picked, were an aggressive bunch of good fliers willing to collectively analyse, learn and improve. Subsequent teams have proved no less and that’s what makes the Sarang so good.

[vasu_ray]

Thanks Koti, Hari Nair, good to be educated about the mm and gun recoil, couple of points,

if the gun mount on the underside of the LCH be mounted on an underside 'generic' pylon so that depending on the operational need it can be changed. For a gatling gun mount, it should be made swivel less so that the recoil always travels along the length of the armored LCH

if the heli is positioned closer to the ship(s), its CIWS is potentially effective against the surfacing torpedoes

depth charges and AUVs are definitely other options, probably another discussion

[ArmenT]

The heli engages with its onboard gatling gun which can penetrate the water surface upto 10m in depth.

In which universe, may I ask? Water is a powerful slowing medium. If you have the angle too shallow, the bullets could just skip off the water. If the angle is too steep, faster moving bullets just shatter on impact.

Mythbusters did a penetration test with various firearms, shooting into a ballistic gel target in a swimming pool. Shooting at an angle, a 50 cal. bullet from a Barrett slowed down so significantly in under 3 feet of water to the point where it wouldn't penetrate a human body. Shooting at a different angle just shattered the bullets when they hit the water.

[vasu_ray]

if the shell say has a 10cm tungsten tip, it releases a gas puff when it contacts the water surface making the shell entry possible, it then maintains its trajectory but not the momentum and hence needs to explode close to the torpedo using a timing mechanism, the shell wraps a 'underwater grenade'

since this is a continuous firing, the probability of intercept is very high

[shiv]

What caliber of Gatling gun are we talking about here? I think anything less than 20 or 30 mm would be pointless if a target was more than a meter underwater. "Low" Rates of fire like 2400 rps would need a storage magazine of 2400 shells to provide 1 minute of fire - I would expect gun and a minute worth of ammunition to weigh 10-15% of the weight of a 5 ton helicopter such as the LCH and make of 40% of the weight of a Chetak based UAV.

A few seconds second of fire is hardly enough to "fill an area with metal" If I were submarine commander I would use 2 torpedoes.

Better to mount the CIWS on the ship where an extra 10,000 kg of CIWS ammunition spread over 3-4 guns would hardly make a difference to the weight of the ship. OT

Besides - for a nation that has barely produced its own machine gun - developing a Gatling and fancy ammo would be spread over the next four 5 year plans. If we start today.

[shiv]

If you watch videos of CIWS against incoming missiles you find them firing off an intense burst of fire lasting several seconds.

"Brrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrrr"

It's never "Brr Brrbrr Brrrrrr Brrr"

An endless supply of ammunition is only one part of the story. An aircraft is actually slowed down by such a gun which is like a rocket engine firing in the wrong direction. The recoil of a Gatling gun is similar to the principle of a rocket engine.

Each projectile weighs in at about 200-250 grams. Firing off 2400 of them (if not more) in one minute is firing off 600 kg of weight in 1 minute. Guess what that would do to a 6 ton helicopter - leave alone a 3 ton helo. The total weight of a Chetak helicopter - the planned NRUAV is less than a few seconds of ammunition.

[negi]

^ Yep if one would look at Avenger/M61 vulcan or even CWIS like PHALANX or Goalkeeper they are heavy and need to be mounted on a rugged frame/structure. Moreover given the sheer size and power of the sonar suite on modern frigate it would in any case stand a better chance of detecting and tracking an incoming torpedo.

Also unlike the older generation torpedoes the modern ones travel a lot deeper , faster and employ pump jets so there is no visible characteristic trail which can be seen from the surface, I wonder how can any helo detect such targets, tracking is all together a different ball game (unless it gets lucky i.e. catches it on HELRAS or similar system) ?

[Gaur]

My knowledge of Naval Systems is almost non existent. However, a quick search using wiki reveals that there is no gun based CIWS in existence which can defend against a torpedo. Also, armenT's post regarding ineffectiveness of bullets in face of high stopping power of water makes sense. So, from where does this talk of using CIWS against torpedo arise (leave alone a helicopter mounted CIWS which would present its own unique problems)?

[shiv]

I guess any reduction in noise is welcome for civil applications, provided the cost-benefit ratio is favourable.

In fact most of the links I saw about "Blue Edge" suggest exactly that. The use of civil helicopters in cities in the west is huge and noise limits are a big thing in the west unlike here in Bangalore where the average autorickshaw minus muffler is noisier that any Dhruv flying overhead.

Only one blog makes a dramatic reference to this main rotor tech by saying "Bad news - there is no stealth helo. Good news its coming now because of Bue Edge" That sounded like marketing hype from a company that has tested that tech for a mere 75 hours at last reading and absolutely no mention made of any effect the rotor design may have on performance. That is why my first impression was that of something that is being pushed for sales by nifty marketing rhetoric.

Other than some midnight stealth for inserting men - I was always under the impression that a battle zone is very noisy with tanks, trucks, guns and all making a noisy helicopter firing missiles from more than 2 km off only a minor player in noise levels. Besides - no matter how noise-stealthy an helo is - the minute its guns burp it will be detected and with a well armed adversary a dozen men and vehicles with anti-aircraft weapons will cue in on the helo no matter how blue its rotor edges are.

[neerajb]

If my memory serves me right, It was mentioned in "Great Planes : A10 Thunderbolt II" that the whole GAU-8 assembly with feed mechanism and ammunition weighs close to 2 tons (1800 or 1900 Kgs). The loadout of 1100+ rounds gives it a total fire time of 15-16 seconds, not to mention the recoil. The gun cancels the thrust of engines when fired in flight, which is 18000 pounds. IMHO such weapon is impractical for any rotary UAV.

Cheers....

[vasu_ray]

By loosening the term CIWS, since the speed of a torpedo is no comparison to a fast moving anti-ship missile

if there is a prediction of the torpedo path the gun can basically mine its probable paths with screens of 'grenades' and need not create an underwater 'wall of lead', so this may not require 40% of the heli weight, agree getting this done is a whole different problem, however ballistics research can be computer simulated

since its a rotary UAV loss of forward motion due to gun recoil has no impact on its ability to stay in air

using a heli gets you closer to the torpedo implying lesser requirements on range and accuracy, anyways this is an LCH thread and its timeout for me

[nits]

Hari Sir - Very Novice question but can't resist asking - Whether we will get to see our LCH in IAF Grey Color or it will be always in default black color....?

[Manish_P]

@nits - (am an noob too so pls. indulge) I would think the LCH colors will be as per the terrain where they are deployed.

I personally would love to see this stalking beast in Grey and White disruptive pattern camo in the mountains, Sandy Brown & Tan pattern while on the west desert deployment

But like you, i eagerly await enlightenment directly from the Oracle, Shri Hari Nair

[Tanaji]

The gun cancels the thrust of engines when fired in flight, which is 18000 pounds. IMHO such weapon is impractical for any rotary UAV.

Cheers....

Minor nitpick, no disagreement to the point you are making:

The recoil force of the GAU-8/A[14] is 10,000 pounds-force (45 kN),[3] which is slightly more than the output of one of the A-10's two TF34 engines (9,065 lbf / 40.3 kN each).[15] While this recoil force is significant, in practice cannon fire only slows the aircraft a few miles per hour.

http://en.wikipedia.org/wiki/GAU-8_Avenger