Why HAL Dhruv helicopter is the perfect platform for Indian Navy

ALH Dhruv
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As the Indian Navy desperately awaits for the replacement of its ageing fleet of  Chetak Helicopters, focus has again shifted to the ALH Dhruv Mk3, modified for shipborne operations, which is ready.

On February 5, 2021, the Indian Navy tweeted that it has received three Advanced Light Helicopter MK III (MR). In February 2021, HAL announced that it had rolled out the 300th Advance Light Helicopter out of its production line in Bangalore.

Earlier we reported that Indian Navy to meet its long-pending requirement of Naval Utility Helicopters (NUH), the Navy to procure 60 Advanced Light Helicopter modified for ship-based operations.

Indian Navy ALH Dhruv MK3
Indian Navy ALH Dhruv MK3

ALH Dhruv mk3 has additional equipment such as a modern surveillance radar and electro-optical equipment to carry out maritime reconnaissance as well as long-range search and rescue missions, an HMG and the capability to mount at least 2 ASW torpedoes.

About NUH and Naval ALH in brief:

  • ‌Advanced Light Helicopter (ALH) was chosen as a single common platform capable for performing sweeping range of roles at altitudes from sea level up to 6km above the sea level.
  • ‌Naval Staff Qualitative Requirements (NSQR) was provided by the Indian Navy in 1985.
  • First flight of Naval ALH prototype took place on 1993 with CTS800 turboshaft engine from US.
  • Development and funding of the programme was hit to some extent due to 1991 Economic Crisis.
  • Later due to sanctions after Pokhran Nuclear tests, the intended engine CTS800 was embargoed and later replaced by Turbomeca TM 333-2B2 engine in naval ALH Mk1.
  • After almost 2 decades of development trials and flight testing, Indian Navy was unhappy with the ALH over key areas such as range & endurance, blade folding, stowed dimensions, aircraft availability and serviceability.
  • As a result, only 8 ALH Mk1 were inducted by the Indian Navy that too for offshore operations at 2 locations in the Western Coast.
    Indian Navy finally issued a RFI (Request for Information) in 2008 mentioning specifications to buy 111 Naval Utility Helicopter from foreign vendors as ALH wasn’t upto the mark then as per the Navy.
  • As Strategic Partnership (SP) model was introduced in the MoD (Chapter VII of Defence Procurement Procedure, 2016) based on Dhirendra Singh Expert Committee’s recommendation to encourage private sector defence production. NUH was the first projects allotted to SP model and is valued around INR 21738 cr. for 111 helicopters.


Crucial Advantages of NavalDhruv Mk3 over Foreign NUH Contenders:

The major concerns highlighted by the Indian Navy on ALH were based mainly on their experience with the limited series production line up of ALH MK1s produced in the year 2000, which didn’t meet the NSQRs of that time. According to Wg. Cdr. (Retd.) Anil Bhambhani, presently Senior Test Pilot (Rotary Wing), HAL, most of these concerns have been since addressed in its current iteration, the ALH Mk3.
Let’s delve in, and see how the ALH Mk3’s enhancements hold up when compared to other contenders in the NUH line up (viz. Airbus Panther, Kamov Ka-226T Naval, Sikorsky S-76D and Airbus H135M):

HAL Dhruv Mk III with Machine gun
HAL Dhruv Mk III with Machine gun

1. All Up Weight (AUW):

While Indian Navy initally stated a 3.0 ton AUW (total weight of the helicopter when fully loaded) to replace its ageing Chetak (also a 3.0 tn chopper) fleet in the RFI in 2008, this was subsequently increased to 5 ton, most probbaly to allow more foreign contenders (esp. Airbus Panther) in the NUH. Airbus Panther, which is the top contender among the foreign manufacturers, has the AUW of 4.5 ton (higher than the other foreign contenders for NUH).

ALH Dhruv for Navy
ALH Dhruv helicopter with torpedoes

In comparison, the ALH Dhruv Mk3 (5.5 ton category chopper) with a superior engine than Mk1 (Turbomeca Shakti engine) & capable composite airframe has the AUW of 5.75 ton. Even if the Navy remains firm on their AUW limit of 5 ton, the ALH Mk3 can easily meet the AUW requirement by removing systems which are not deemed necessary under the NUH guidelines, (such as sonar, surveillance radar, conventional V/UHF systems (digital intercommunication systems), rear main tank etc.) while adding 2 segmented/tail boom blade folding measures, weather radars, slewing Sling Load, software defined radio, weather radar, which are considered essentialunder the same NUH NSQRs. Further, the ALH Mk3 will still retain the  flexibility to add 1.25ton extra weight if any operational requirements so necessitate.

2. Blade Folding:

Blade Folding is essential for any naval helicopter so that it can be stowed easily and can fit into the its mothership’s hangar. ALH had its fair share of challenges in blade folding due to its large hinge offset and large rotor head required for 3.5G maneuvers required by the Army and IAF versions (let’s remind ourselves, the ALH was chosen as a single common platform to perform a sweeping range of roles). HAL proposed 2 methods to overcome these challenges:

i) The 2 Segment 4 Blade folding was demonstrated in HAL Light Utility Helicopter and the time taken in blade folding was about 6 minutes, well within the requirements of NUH and was seen as an effective option for ALH Mk3 to meet the stowed requirements of NUH.

ii) The Tail boom folding was demonstrated on 7 Nov 2020 in ALH Mk3 DMDW prototype and earlier in a mock up model in Aero India 2019. The Tail boom folding in combination with existing 2 blade folding achieved stowage dimension of 13.5m length, 3.5m width, 4.1m height & meets the NUH specifications.
As per the reports of Economic Times in mid-April 2021, the modified ALH Mk3 with folding tail boom is ready and the Advanced Light Helicopter (ALH) and is undergoing development tests and trials at HAL facility.

3. Range and Endurance:

ALH Mk3 has a clear advantage of range and endurance over the rest of the foreign contenders if ALH is allowed to use its full capacity of 5.75 ton (which allows it to carry more fuel, thereby extending its range). Though the glass ceiling of 5 ton (changed from what was originally 3 ton in the Navy’s RFI in 2008) is clearly not a deck limitation. But even if the Navy’s 5 ton limit is taken as the threshold limit for the NUH, ALH MK3 still has a better range than all of its foreign competitors as the Specific Fuel Consumption of the current Shakti engine used in ALH Mk3 is lowest,i.e. 0.300 kg/kw hr in comparison to the rest of choppers in contention under the NUH, (above 0.300 kg/kw hr for all the choppers, 0.333 kg/kw hr in Arriel 2C engine of Panther, the nearest competitor to ALH Mk3 in NUH).

4. Sub-Surface Targeting Capability& Cabin Volume:

Sub-Surface Targeting is listed as one of essential requirement as per the NUH, apart from ALH, only Panther has demonstrated maritime radar and lightweight torpedo carrying capability, while the rest contenders don’t even meet this requirements.

Also, ALH has a larger cabin volume than the most other NUH contenders and has the capacity to accommodate 12 crews as compared to 10 in Panther, 8 in Ka-226T, 8 in H135M. Only S-76D can accommodate 12 crews like ALH.

5. Maintenance:

Maintenance has been a major issue for the naval ALH in the past, leading to significant Aircraft on Ground Rates. But this has been addressed by HAL by signing Performance Based Logistics (PBL) with OEMs to provide guaranteed 75% of total fleet availability at any given time. This PBL worth INR 8000 cr was cleared by the GOI in 2017 for 32 ALH Mk3 of both Indian Navy and Indian Coast Guard for a period of 5 years for integrated, affordable, performance package designed to optimise system readiness and meet performance goals through long term support arrangements.

6.Platform Upgrade & Obsolescence Management:

HAL, the owner of design IP in ALH is capable of handling any type of unilateral upgrades, additional requirement of change in specifications, integration of new weapons, sensors etc. with considerably less effort, and more importantly,without much involvement of foreign OEMs. Being an HAL product, the obsolescence issues during entire product life cycle can be effectively addressed by HAL.
Dependency on foreign OEMs for continuous upgrades and obsolescence can lead to enormous cost and considerable drain of foreign exchange.

7. Cost

With the already setup infrastructure at naval bases and commonality with the existing fleet of 32 ALH Mk3 of Indian Navy and Indian Coast Guard for shore based operations, there is no need to setup additional infrastructure or pay royalty to the OEM if the SP route is adopted by selecting a foreign partner. Also with ALH being an indigenous design, Transfer of Technology isn’t required which saves significant additional costs. As already discussed above, ALH also saves substantial cost on upgrade and obsolescence management.

Opportunity for HAL

The delay in acquring NUH choppers via SP programme with foreign partners has given a lifeline for HAL and they must grab this opportunity with both hands without any further delays and must  expeditiously certify the blade folding, the proverbial ‘albatross around the neck’ for the HAL for almost 2 decades. The Indian Navy, also referred to as the ‘Builder’s Navy’, has been known to support indigenous programmes and has been a part of ALH development for almost 2 decades. Now it’s time for HAL to deliver because any more delay will be a loss to the Naval Aviation, which has been unfortunately operating 60 yr old Chetak helicopters. Yes, HAL has had its fair share of challenges in developing the first indigenous chopper as a common platform for the 3 forces. With only a handful of dozen helicopter manufacturers in the world, making a state of art helicopter from scratch with advanced technologies like glass cockpit, hingeless rotors, and composites is a significant achievement for HAL. Now it is high time HAL delivers the ALH Dhruv tailor made for NUH requirements as early as possible.

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