Indian Military Helicopters

vivek_ahuja · Post by **vivek_ahuja** » 09 Mar 2015 23:36

BTW: while you all are it, can you find some good numbers for the empty weight of the HAL bird too? Its performance seems so much better than the others that I want to make sure I am not doing a flawed analysis...

Thanks in advance.

Cybaru · Post by **Cybaru** » 09 Mar 2015 23:48

Dunno how accurate.

Empty Weight
http://www.flugzeuginfo.net/acdata_php/ ... 226_en.php
Empty Weight 1.950 kg 4.300 lbs

Singha · Post by **Singha** » 10 Mar 2015 06:55

it can only be known for certain when the LUH flies....generally HAL estimates have been fancifully on the lower side ... you might want to take whatever weight is out there and do a 3 more graphs of +10%, +20, +30

Mukesh.Kumar · Post by **Mukesh.Kumar** » 10 Mar 2015 08:16

Is there any update on the Dhruv crashes from Ecuador? Two of the birds crashed within a week of each other in January. The silence seems ominous.

rohitvats · Post by **rohitvats** » 10 Mar 2015 09:36

vivek_ahuja wrote:<SNIP> Will do. So I did the original work in 2007 timeframe. I have updated plots now because I improved the modeling last year. I will put together all of the new plots and send them to you to put up. What's your preference on that: should I compile all of it into a set of articles with some analysis or just give you the raw performance plots to put up to help foster the discussions here? <SNIP>

The bold part should do.

Pratyush · Post by **Pratyush** » 10 Mar 2015 10:11

Mukesh.Kumar wrote:Is there any update on the Dhruv crashes from Ecuador? Two of the birds crashed within a week of each other in January. The silence seems ominous.

The court of inquiry will take its time before it comes up with any answers. So no need to be worried about it.

sankum · Post by **sankum** » 10 Mar 2015 16:36

vivek_ahuja Sir,
The basic empty weight of HAL LUH is 1910 Kg and MTOW is 3117 Kg as per info board shown in AI-2015.

Can you please add the analysis for wheeled version of HAL LUH whose empty weight can be estimated to be 2025 Kg (115Kg higher than skid version) as this will be offered to Indian Navy.

Singha · Post by **Singha** » 10 Mar 2015 17:25

so how did HAL achieve the miracle of making the LUH weigh twice as much as the Bell-407 which is of the same dimensions and has same one engine ?

http://www.bellhelicopter.com/en_US/Com ... 32291.html
Weights
Empty wt 2,691 lbs 1,221 kg
Std internal gross wt 5,000 lbs 2,268 kg
Optional internal gross wt 5,250 lbs 2,381 kg
External gross wt 6,000 lbs 2,722 kg
Useful load, standard 2,309 lbs 1,047 kg
Useful load, optional 2,559 lbs 1,160 kg
Max ext load (cargo hook limit) 2,646 lbs 1,200 kg

probably the LUH is quoting things with full internal fuel == std internal gross weight.

shiv · Post by **shiv** » 10 Mar 2015 17:26

Mukesh.Kumar wrote:Is there any update on the Dhruv crashes from Ecuador? Two of the birds crashed within a week of each other in January. The silence seems ominous.

You missed an earlier discussion. One was a training accident that could be trainee pilot error. The video was posted here.

sankum · Post by **sankum** » 10 Mar 2015 19:03

Of the 4 Dhruv crashes of Ecuador first two were pilot error and 4th one as given above by Shiv was also a possible pilot error while the reason of third crash is unknown.

Of the 12 Dhruv crashes so far one of IAF is possible mechanical fault which went down in a fireball and one is unknown while rest 10 are whether related or mostly pilot error. Otherwise Dhruv is a safe platform.

sankum · Post by **sankum** » 10 Mar 2015 19:31

HAL LUH is in the class of Bell 429 whose empty weight is 1925Kg and MTOW is 3175Kg and not Bell 407 whose empty weight is 1221 Kg and normal TOW is 2268Kg while max with sling load is 2700Kg+.

The figures can be expected to be accurate as with sling load MTOW for HAL LUH may be 3600Kg which is not disclosed so far.

srin · Post by **srin** » 10 Mar 2015 20:49

Singha wrote:so how did HAL achieve the miracle of making the LUH weigh twice as much as the Bell-407 which is of the same dimensions and has same one engine ?

http://www.bellhelicopter.com/en_US/Com ... 32291.html
Weights
Empty wt 2,691 lbs 1,221 kg
Std internal gross wt 5,000 lbs 2,268 kg
Optional internal gross wt 5,250 lbs 2,381 kg
External gross wt 6,000 lbs 2,722 kg
Useful load, standard 2,309 lbs 1,047 kg
Useful load, optional 2,559 lbs 1,160 kg
Max ext load (cargo hook limit) 2,646 lbs 1,200 kg

probably the LUH is quoting things with full internal fuel == std internal gross weight.

The Shakti engine has double the power output of the Bell's.

atul.arvind · Post by **atul.arvind** » 11 Mar 2015 15:07

Noob question ..IIRC Rudra was already inducted in arm forces or still under development ...coz saw one today at HAL in yellow paint pattern which LCA TD's used to have

vivek_ahuja · Post by **vivek_ahuja** » 15 Mar 2015 16:23

@Rohitvats:

Saar, I have the first article on the LUH competition written down. I will email you the PDF document, but I am also posting the small article here.

-Vivek

sankum · Post by **sankum** » 15 Mar 2015 16:48

Thanks vivek_ahuja. Hal Luh is being designed for higher performance than its competitors.

Singha · Post by **Singha** » 15 Mar 2015 17:20

Problem is luh will be dead if they come with 750kw
And ask for 5 years to make chanes to boost it.
The first proto has got to be competitive to stand a chance.

This is not a lch or alh with no competitive tender.

We really need to replace the old chetaks and cheetals.

Looking at graphs i am not hopeful hal is designing for success here

abhik · Post by **abhik** » 15 Mar 2015 18:41

Where is this 750kw figure coming from? I thought they always planned to use the shakti engine.

vivek_ahuja · Post by **vivek_ahuja** » 15 Mar 2015 19:07

abhik wrote:Where is this 750kw figure coming from? I thought they always planned to use the shakti engine.

They are planning to use the Shakti engine. That's why the analysis shows the solid blue line if they use that. But during the HAL presentation on the LUH, there was some obfuscation where they stated the 750 KW power value, but didn't specify whether it was the transmission limit for the rotors or the rated engine power.

So to get around that problem, I made two sets of plots. The 750 KW plot is made with dotted lines for that reason alone. Think of it as a worst case scenario. The solid blue line shows the ideal limits that the LUH can get with the Shakti engine (1067 KW).

And I wrote in the article the same:

However, if we assume that the implied 750 KW is simply the transmission limitation and not the engine output (which is 1,067 KW), then the performance of the HAL design far exceeds the performance of its competitors and can haul usable payloads up to an altitude of ~21,000 ft despite the much higher empty weight.

I am pretty sure the 750 KW value is indeed the transmission limit. If that ever gets confirmed, go with the solid line in the plots above.

-Vivek

kvraghav · Post by **kvraghav** » 15 Mar 2015 20:25

The fennec is around 1.2 tons empty weight and 2.5 tons MTOW which means a loadout of around 1.3 tons but the passenger capacity is just 4. The LUH figures is around 1.9 tons(wiki says 1.6 but AI figures may be the actual ones after weight issues) and MTOW of 3.2 tons, the loadout again is 1.3 tons but the LUH has passenger capacity of 6. What this might mean is the body may be larger than fennec.

kvraghav · Post by **kvraghav** » 15 Mar 2015 21:19

Intersting to note that all the other helicopters have 3 rows of windows, fennec has two but LUH has 4. Is there any length comparison of cabin?

sankum · Post by **sankum** » 15 Mar 2015 22:50

HAL's Light Utility Helicopter

Slide on HAL LUH

Power
Transmission limit:(at SL)
Take off power=750 kW
Max. continuous power= 620 kW

Payload
At Sea level
Internal= 500Kg
Underslung=1000Kg
At 6Km 75Kg

Service ceiling>6.5Km (max AUW)

Vertical rate of climb 5.5m/s

Oblique rate of climb 7.5m/s

sankum · Post by **sankum** » 15 Mar 2015 23:55

With underslung 1000kg load HAL LUH MTOW will be 3600Kg.

Indranil · Post by **Indranil** » 16 Mar 2015 00:52

sankum wrote:

Thanks.

sankum wrote: HAL's Light Utility Helicopter
Slide on HAL LUH

Power
Transmission limit:(at SL)
Take off power=750 kW
Max. continuous power= 620 kW

For comparison, the transmission limit for the Ardiden/Shakti 1H1 powering the Dhruv is:
Take off power=741 kW
Max. continuous power= 650 kW

Shreeman · Post by **Shreeman** » 16 Mar 2015 05:30

Why are there no pictures of the LUH GTV?

Singha · Post by **Singha** » 16 Mar 2015 10:42

is there a way your posts can be made sticky on BR? threads can be made sticky but I am not sure of posts.

we seldom see such comprehensive take downs

if you have time could you add in the curves for the redoubtable AH-64D as well. that should indicate if the famous 22 we want to buy how useful they will be or just ego massages.

to fight in daulat beg oldie for example, I think helis need to fly through valleys around 17000ft AGL..and over the khardung la gap down into the Nubra valley. there is no other means of deploying them there, whether by road or C17.

likewise to get to SE sector of ladakh it another set of tall passes whether from the north or south....they must be able to haul themselves over 15,000ft passes even if weapons and fuel travel by road.

shaun · Post by **shaun** » 16 Mar 2015 13:41

vivek saab , which engine of Z-10 have been considered for this analysis ?

vivek_ahuja · Post by **vivek_ahuja** » 16 Mar 2015 18:17

Singha wrote:is there a way your posts can be made sticky on BR? threads can be made sticky but I am not sure of posts.

So Rohitvats had suggested perhaps putting up links to the articles in PDF formats to add them to the first page of this thread like how we do in the strat-forum dhaga?

Shaun wrote:vivek saab , which engine of Z-10 have been considered for this analysis ?

So I read online that the Z-10 is either powered by the WZ-9 Turboshafts or the Pratt & Whitney PT6C-67C engines. Both are roughly in the 1000 KW range with the P&W engine slightly better (~1,100 KW). I assumed the WZ-9 engine for this analysis. The results will not be that much better even with the P&W engine (i.e. perhaps it will come closer to the Mi-35 performance in the plots above).

-Vivek

John · Post by **John** » 16 Mar 2015 18:26

More than likely Mi-35 are short term procurement, Z-10 is out of picture. More than like once T129 quirks are ironed out and production T129B begins, Pakistan will procure them IMO. What is your take against that?

vivek_ahuja · Post by **vivek_ahuja** » 16 Mar 2015 18:32

John wrote:More than likely Mi-35 are short term procurement, Z-10 is out of picture. More than like once T129 quirks are ironed out and production T129B begins, Pakistan will procure them IMO. What is your take against that?

Good question. I think I need to do an article similar to the one above for the Pakistan specific options. Might even have to post it on the Paki arms thread, since this one is focused on the Indian military birds. These would most likely include analysis of the following:

U.S. AH-1 Cobra
Turkish T129
Russian Mi-35
Z-10?

Are we missing any other options for the Pakis?

-Vivek

Singha · Post by **Singha** » 16 Mar 2015 19:48

the Z-10 how can it have P&W engine if china is under EU-US arms embargo?

another Paki option is the Rooivalk, but a Italian product is far more likely as it gives them access to better western engine and technology. turkish arms spending is far more than SA so A129 has a future. only 12 rooivalk built.

John · Post by **John** » 16 Mar 2015 21:25

Singha,

A129 is no longer offered for export, rather Agusta and TAI are promoting T129. Erdogan is desperate to enhance his relationship with Muslim nations and with great certainty they will push t129 to Pakistan. Rooivalk is very interesting but i think Turkish decision to choose A129 derivative sealed its fate.

Vivek,

Thanks also even Mi-28 is not out of picture down the road, will allow Pakistan to use all existing weaponry of MI-35.

Cosmo_R · Post by **Cosmo_R** » 16 Mar 2015 21:32

Singha wrote:the Z-10 how can it have P&W engine if china is under EU-US arms embargo?

another Paki option is the Rooivalk, but a Italian product is far more likely as it gives them access to better western engine and technology. turkish arms spending is far more than SA so A129 has a future. only 12 rooivalk built.

"Of the $75 million UTC is paying, $4.6 million represents a fine to Pratt & Whitney Canada and $2.3 million represents its profit from the sale and will be forfeited by Pratt.

Congress placed China on an export embargo list shortly after the 1989 Tiananmen Square massacre."

http://www.ctpost.com/local/article/UTC ... z1zCDcsqDv

Aditya G · Post by **Aditya G** » 16 Mar 2015 22:08

Thanks for the analysis Vivek. There could be other reasons for choosing the Mi-35 as well:

- Commonality with Mi-17: Mechanicals and weapons
- Configuration: Troop capability, though seldom used

Viz a viz high altitude performance, does Pakistan even have a use case? My understanding is that high altitude theatre in J&K is much deeper on our side compared to Pakistan. There the aircraft can take off from the plains, while here it is not possible.

Could you also add Cheetah to the comparo?

vivek_ahuja wrote:... The reason for doing so is to illustrate why the Pakistanis went for the Mi-35 option when the spanking-new Z-10s were on the table. The Mi-35 performance for high-altitude conditions is dismal. This is a fact known in Indian Air Force circles for many years and has led to the genesis of the LCH. But as bad as the performance for the Mi-35 is in the mountains, it is still better than the Z-10. At sea-level, the Mi-35 can completely outperform the Z-10 for ROC capability. Its ROC tail-off at high altitude is at ~9,500 ft. Its payload tail-off is at ~12,500 ft. Both these numbers are better than that of the Z-10. Coupled with lower operating costs and generally rugged reliability, the Pakistani decision to pursue the Mi-35 becomes clearer....

Indranil · Post by **Indranil** » 17 Mar 2015 00:03

Excellent posts.

I am in favour of making a gyan only thread for Vivek sir's analysis. On the lines of the Kaveri gyan thread by Maitya sahab. It will be strictly moderated, and is meant to be used by agyanis only for reference.

Singha · Post by **Singha** » 17 Mar 2015 07:04

Vivek feel free to start a new helicopter analysis thread.
We will move your above posts there.

sankum · Post by **sankum** » 17 Mar 2015 07:38

LCH combat mission take off weights estimates.

AA UAV hunting
8*mistral AAM,
empty weight 2800 kg+1100kg fuel+200kg pilots+200kg cannon ammo/chaff flare etc.+220kg 8*mistral aam=4520 kg

Anti tank mission
2*quad pack Helina+ 4*mistral aam
empty weight 2800 kg+1100kg fuel+200kg pilots+200kg cannon ammo/chaff flare etc.+680kg 2*quad pack Helina+110kg 4*mistral aam=5090 kg

Ground attack
2* twin pack Helina+ 2*12 70mm FZ rocket pods
empty weight 2800 kg+1100kg fuel+200kg pilots+200kg cannon ammo/chaff flare etc.+340kg 2*twin pack Helina+(204kg/256kg/364kg) 2*12 70mm FZ rocket pods=4844/4896/5004 kg
for standard/heavy/ laser 70mm FZ rockets (6.3kg/8.5kg/13.25kg single rocket weight) respectively.

The external payload varies from 220kg to 790kg max.

The overall weight of twin pack Helina is 170kg as given in one of the previous expo video presentation is scaled for quad pack at 340kg.

Singha · Post by **Singha** » 17 Mar 2015 08:55

I have moved Vivek's post to a new thread title "helicopter performance analysis"

vivek_ahuja · Post by **vivek_ahuja** » 17 Mar 2015 21:03

New helicopter analysis article is up on the special dhaga:

Why the Apache is a brute and LCH is elegant

Pliss to visit and read.

-Vivek

Singha · Post by **Singha** » 17 Mar 2015 21:43

I suspect the J31 and J20 are struggling with the same lack of powerful , fuel sipping engines where the JSF can draw on brutishly powerful yet economical and reliable engines.

the F-18EF could get a EPE version of 414 if funds can be found to buy new model engines. this will help its otherwise not so sports car airframe.

srai · Post by **srai** » 18 Mar 2015 05:08

indranilroy wrote:Excellent posts.

I am in favour of making a gyan only thread for Vivek sir's analysis. On the lines of the Kaveri gyan thread by Maitya sahab. It will be strictly moderated, and is meant to be used by agyanis only for reference.

This is where a BR Wiki would be nice instead of a forum thread. Forums are great for discussions and compiling information but Wiki is better for organizing and rendering that information for consumption.