HAL's Light Observation Helicopter (LOH)

[Guest]

This material has been OCRed from Vayu 2000 Aerospace Review, III/1999<P>The Author is H.P. Mama<P>HAL's Light Observation Helicopter<P>India's Hindustan Aeronautics Ltd. (HAL) has announced that preliminary work is underway on a Light Observation Helicopter (LOH). It will be in the 3 tonne all-up weight class, and will have a rather high useful load of 1,500 kg. The LOH will be designed for operation at high altitudes of up to 6 km.<BR>It will differ from the present Advanced Light Helicopter (ALH) in having an<BR>all-composite fuselage structure. While the ALH main rotor has elastomeric bearings, that of the LOH will be bearingless. Torque will be countered by a "Fenestron" type ducted tail rotor. All these three technologies will be applied for the first time on an Indian designed helicopter. Among other features of the LOH will be a glass cockpit, and a Health and Usage Monitoring System. In other respects, LOH will have considerable commonality with ALH, particularly in systems and instrumentation.<BR>No mention is made of whether LOH will have a single or twin-engined layout. However, its high-altitude requirement would indicate the use of two engines. That means there will not be any engine commonality. LOH will be in roughly the same category as the 2.7 tonne EC 135. Unlike the ALH, which had<BR>technical collaboration from Eurocopter-Germany, LOH may be entirely indigenous. By the time LOH production begins, the line for Chetak (Alouette III) and Cheetah (Lama) will have finally come to an end. Interestingly, a number of advanced technologies on the LOH are to be integrated into the ALH. The latter is to have a higher percentage of composites in its structure, notably in the bulkheads. Like the LOH, ALH will also have a glass cockpit, a Health and Usage Monitoring System, a bearingless main<BR>rotor and a ducted tail rotor. Additionally, the designs of its mast bearing, transmission system and landing gear are being simplified. Sextant Avionique is known to be among those to have offered a complete<BR>glass cockpit for the ALH. Efforts are being made to reduce the ALH's weight, as well as production, operation anb maintenance costs, and to improve overall efficiency. While ALH<BR>is already the "most advanced helicopter in the 4.5 to 5.5 tonne class", these<BR>improvements should make it that much better.<BR>The Light Attack Helicopter (LAH), displayed in model form during Aero India '96, was not in evidence at the last show. In any case, it remains a possible project for the future.<BR>Another Indian rotory-wing Project recently announced is "an unannounced helicopter for the armed forces". No further information has been released to-date.<P>(Note: No information on any of these projects was officially offered at the HAL stand. This material is exclusively from a paper presented by HAL Chairman, Dr. Nair, and Dr. Harinarayana at the concurrent seminar.)<P>- Hormuz P. Mama<P> <A HREF="http://personal.vsnl.com/cybersurgeon/loh.jpg" TARGET=_blank>http://personal.vsnl.com/cybersurgeon/loh.jpg</A> <p>[Note: This message has been edited by Rakesh Koshy]

[Badar]

Hi,<P>Shiv, thanks for bringing it to our attention.<P>1. How does a bearingless rotor work?<BR>2. Any speculations as to what this "unannounced helicopter for the armed forces" is? <BR>3. Why announce the project and provide no details at all? If the project was so classified then why acknowledge its existance in the first place? Something not kosher here.<P>

[Badar]

Hi,<P>Salman, they all tend to look a little similar, look at the Bo 105 for instance. Its more a case of similar requirments, similar designs.<P>I second you on your other point, we seem to have way too many aviation projects on our hand than we can possibly complete.<BR>

[vverma]

Badar & Salman, I have to agree that all these orgn have their hands full with new projects being announced everyday. Kalam is trying to reach his "70% indigenous" goal. <P>But as far as this project is concerned, HAL seems to be perfectly timing this one. HAL's helicopter division is almost finished with the ALH. All three Defense Services are testing it. So, the design engineers have started working on the next project. <P>Is this going to be something that the GoI will force the Armed Forces to buy when they don't need it? It would've made sense if they'd taken the next logical step, i.e. an attack chopper on the lines of ALH and/or a heavy lift helicopter like the Chinook/Mi-26.<P><BR>BTW, speculating on the "unannounced helicopter for the armed forces", I think HAL might have taken the next logical step and could be developing an attack chopper on the lines of ALH.

[vverma]

Salman, I know the LAH(Lancer) project inside out. It is by no means an "attack helicopter". It is just a beefed up Cheetah with two MGs and a total of 6 rockets. That is hardly enough fire power to even take on a platoon. It is only good enough for taking on intruders on snowy heights like in Kargil. <P>What I'm talking about is a full size(6 tons class) attack chopper capable of carrying a wide range of armament with all state of the art goodies.

[Bharat]

What is this about an unannounced Helicopter program..Also when is the LOH being rolled out.Also can it carry Anti-tank missiles or ground attack machine guns.Also 6 kms is 20000ft.so is the copter idea emerging after Kargil.If yes then it'ss 6-10 yrs in tthe making.By this time thee ASTRA should be out so can the copter fire the ASTRA .I read somewheree that US copter's fire the Stinger.But the concept is good esspecially surveillance in KArgil.Also for a 1500 kg load mean that it can bee used in Special ops as being small it can evade radar by going between mountains .

[Badar]

Hi,<P>Salman, you may be right, but being a teetoler I can't take you up on the 6-pack.<P>BTW, what exactly is a "light observation helo"? what is the intended market/user? FAC/FAO for the IA or as a scout for the ALH based LAH? I would have thought that the ALH itself would have been the ideal candidate for any such ops.<BR>

[Peeyoosh]

May not be a military user profile at all. Users in mind could be police forces, coast guard, industrial users. <P>This seems to be low weight, low cost profile, with reduced maintainance for organisations with a low level of infrastructure.

[vverma]

Like the article states, HAL's Light Observation Helicopter will replace Cheetah and Chetak in the three services.<P>Badar, if there is an attack chopper build based on the ALH, then it won't be called LAH(since it'll be in the 6 tons class). LAH is the Lancer(based on Cheetah). <BR>

[Peeyoosh]

Salman<P>Can we start a tech thread on the choppers being planned inducted by HAL.<P>You being the usual intitiator <P>Peeyoosh

[vverma]

Salman, I was quoting from the website you referred me to. Shiv's website explicitly states that the Lancer project is also known as the LAH project. This makes sense as well because anything based on ALH will be in the 5-6 tons class, by no means a "Light" AH. <P>BTW, can you please give details of the article from "Janes 98/99". A little more specific as to which Janes' book/magazine. I've been hearing speculation about the attack helicopter based on the ALH but I didn't think it was ever initiated. It's possible that it might be that "unannounced" project but doubt it until there's a positive confirmation from HAL.

[Badar]

Hi, <P>vverma, mangusta at a 5 ton mission weight is called a 'light attack helicopter'. A "full" attack helicopter like the Havoc or Apache weighs in at more than 10 tons.<BR>