Govt must look into safety issues with Dhruv

Air Vice Marshal Manmohan Bahadur (Retd)
Former Additional Director General, Centre for Air Power Studies

THE recent ditching of an Indian Navy ALH (Advanced Light Helicopter) Dhruv has rekindled discussions about its safety record; the fact, however, is that the ALH made by Hindustan Aeronautics Limited (HAL) is like no other machine in the world. It was designed and developed as per the IAF’s air staff requirement document of 1983, which asked for a helicopter to operate in the dizzy heights of the Himalayas where our Army was, and still is, deployed. Its R&D, certification and manufacturing story is worthy of a research project that would be of immense benefit to our aviation industry as it attempts to meet world standards — to learn what to emulate and also, what not to.

I was associated with the ALH programme in 1988 when it had just started and design specifications were being made; it was the time when a wooden mock-up was being used to try out various fitments; heady days they were, discussing nuts and bolts of a desi machine. The HAL sought, and was given, many concessions to the original operational requirements and by the end of the 1990s, we finally had a helicopter that entered operational service. Keeping it flightworthy and available on the flightline, however, was a nightmare. Snags were many and the supply chain of spares pitiful. The life of many critical components was extremely limited (which was okay, considering that the machine was new), but their servicing took months on end. Helicopters sent for major overhaul sat in Bengaluru for eons and aircraft offered after servicing had endless snags… the lament list is endless. I was Assistant Chief of the Air Staff in 2009-10 looking after transport and helicopter operations and went through this phase. But it was an Indian design and manufacture and one wished that things would improve.

Things started looking up and the HAL sold seven ALHs to Ecuador in 2008 in the face of stiff competition. Alas, it was doomed as four helicopters crashed within a few years — the first one in the Ecuadorian national day parade. As I saw that crash video, I relived the first ALH crash in Bengaluru in 2007 when a Sarang aerobatic team helicopter spiralled to the ground; I was the presiding officer of the Court of Inquiry and we commented on the design characteristic of the rigid rotor system that the ALH is equipped with; the rigid rotor gives it very high manoeuvrability, but it stalls if rolled and pitched beyond a certain rate. These are technical issues that concern the designer and need quick redressal; the incipient cyclic saturation warning took many years for installation after our recommendation made in 2007.

Now, regarding the ditching of the Indian Navy ALH that happened last week, without taking away any credit from the fine work done by the crew for safe recovery, it indeed is providential that there were no casualties. Very importantly, the Court of Inquiry has a scratch-free helicopter on its hands to find out the cause.

The Navy statement says, “The helicopter experienced a sudden loss of power and rapid loss of height,” and a day later the three services grounded all machines pending investigation. While it is too early to conjecture, but as someone who has been in the business of helicopter flying for four decades, the many recent cases of failure of ‘collective’ or ‘cyclic’ pitch rods come to mind. To the uninitiated, these are the push-pull mechanical rods that are connected to the rotors and enable it to provide lift to fly — move up/down or forward/sideways/rearward etc. These rods are moved by the pilots when they manipulate the ‘cyclic stick’ and ‘collective’ — two primary flying controls in the cockpit. If a rod breaks, it is a catastrophic situation, akin to the breaking of the steering wheel of a car or the tie rod connecting it to the wheels while the car is in motion. The car driver is on the ground and can at least brake for some control; what does a pilot do in the air when his cyclic or collective becomes ineffective? This has been the case with at least five accidents: a fatal one near Allahabad in 2014 where we lost seven personnel, including the Commanding Officer; an ALH Sarang helicopter doing a demonstration at the firepower display at Pokhran in 2009; an IAF ALH high up on the China border in Ladakh; an Army aviation ALH in Leh in 2016; and another one in 2019 with the Army Commander, Northern Command, on board. Is the naval helicopter ditching due to a similar reason? The Navy statement hints at that.

Accidents will happen, but the aim is to keep them spaced apart for as long as possible. Accidents due to human error or equipment malfunction can be prevented by taking procedural and/or technical steps. Design shortcomings, however, are at a foundational level and need immediate institutional remedies. When an aircraft design comes into question, other forces — bureaucratic, institutional and even political — come into play. These have to be avoided like the plague if we want our still-fledgling aviation industry to have a strong foundation. Even one accident is one too many, and here I have narrated five due to the same exceptionally serious cause (anecdotal renderings indicate a few more). It cannot be taken in a chalta hai attitude of a one-time check after every control failure; lives and reputations (of the nation and its aircraft industry) are at stake.

It is time that the government steps in and institutes a truly independent board of professionals to look into all issues with our ALH Dhruv programme.