India’s indigenous helicopter production achieved a significant milestone on March 28, when the government approved the acquisition of 156 Light Combat Helicopters (LCH) ‘Prachand’ for the Indian Army and Air Force for $7.3B. However, another fleet of indigenous helicopters, grounded for over 84 days, is a cause of concern for the Indian forces.
The fleet of 330 Advanced Light Helicopters (ALH) across the three services has been grounded since the crash on January 5.
An ALH Mk-III of the Indian Coast Guard crashed in Porbandar, Gujarat, killing all three crew members onboard. The rotary-wing aircraft had missed the Aero India-2025. A decision on their fate was expected after the final investigation report.
The deadline for the submission of the report was March 3. The deadline has passed, but there is no development on the case. Sources indicate that it could be several weeks before these birds take to the skies again.
“The issue is with the design of the swashplate assembly. There is no redundancy in these components. It could be weeks before the helicopters fly again,” sources told the EurAsian Times. The helicopter has been developing rare defects even after two decades of being handed over to the services. Defense experts have opined that it indicates design flaws.
The Indian Army accounts for 96 ALHs and 75 armed versions called Rudra. The Air Force operates around 70 ALHs. The Navy and the Coast Guard operate the rest.
Sources indicate that the helicopter is still a month away from trials, which will be conducted following changes in the choppers. The chief of the helicopter maker Hindustan Aeronautics Limited (HAL) has accepted that a prima facie swashplate fracture was behind the accident.
A swashplate in a helicopter is a mechanical device that translates the pilot’s flight control inputs into the motion of the rotor blades, allowing for changes in pitch and roll. It consists of a stationary outer plate and a rotating inner plate, which work together to control the angle of the rotor blades as they spin.
The ALH’s swashplate arrangement was heralded as a breakthrough development. All the pitch change rods and swashplates are covered by a titanium drum known as the stub shaft. This titanium drum was supposed to protect the control rods from battle damage and reduce the height of the mast. No other helicopters in this category used such a design.
Helicopter pilot and the Flight Commander of the first Naval ALH flight, Commander YP Marathe (retired), underscored that this covering means that the “mandatory daily inspection of the control rods can never be done on the IDS (integrated dynamics system akin to a reduction gearbox), so any incipient crack or defect remains hidden until a catastrophic failure occurs.”
In his blog post, Commander Marathe said: “The ALH rigid rotor has a very high virtual hinge offset (close to 17%). Due to this offset, the control forces (or the Mast Moment) in turns and manoeuvers can exceed the airframe limits, leading to possible incipient or unrecorded exceedances. Cumulative stresses will lead to catastrophic failures over time.” He added: “If one of the rods connecting to the swashplate breaks, then the pilot’s movement on the cockpit controls will not be transmitted to the main rotor. The helicopter will crash.”
Earlier in 2023, another crash revealed defects related to the control rod (which affected power input to rotor blades) and hydraulics issues. The control rod is essential for transferring power from the copter’s two engines to its overhead rotors.
The control rod in ALH is made of aluminum, and HAL decided to replace it with steel control rods in some helicopters.
Special checks have been put in place for the rod every 100 hours of flying instead of an examination every 300 hours. This will increase the copter’s fatigue tolerance and improve the pilot’s control of the aircraft. A regulatory panel suggested the change.
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Despite retired helicopter pilots indicating a review of the helicopter design, HAL Chief Dr DK Sunil said at the press conference on the sidelines of Aero India, “There is no problem with the design. NLR lab in the Netherlands has reviewed it and certified it.” He underscored that the helicopter has flown over 4.5 lakh hours since its induction in 2004.
He highlighted that the ALH Dhruv has experienced 28 crashes since its induction. These incidents have been attributed to various causes. Thirteen crashes were due to technical faults, another 13 were attributed to human error, and the remaining two had unknown causes.
ALH’s First Export To Diplomatic Fracas
Earlier, the first export of the ALHs to Ecuador ended in a diplomatic debacle.
After a series of crashes, Ecuador grounded its fleet of ALHs and put them up for sale. The country also unilaterally canceled its order for more ALHs from India, which sued the Ecuadorian government over the matter.
The ALH has been sold to Maldives, Mauritius, Nepal, and Ecuador for military use. One of these choppers has been leased to the Israel Defense Forces (IDF). Additionally, states like Turkey and Peru purchased the helicopter for civilian purposes.
Dhruv’s debacle with Ecuador has long haunted the HAL. Since then, the MK III variant has evoked significant interest from various countries looking for cost-effective alternatives to Western military helicopters. The Philippines, Argentina, and North African countries have shown interest in the helicopter.
However, the slew of crashes in the Indian forces, which lead to frequent grounding, can also shake prospective users’ confidence in the choppers. In 2023, the entire fleet of around 330 twin-engine ALHs in the armed forces had to be grounded a few times after four major accidents.
The two pilots of the Indian Army were killed in a crash of ALH in Jammu and Kashmir on May 4, 2023. The Indian Army grounded its fleet of 170 ALHs and undertook a comprehensive safety check. The pilots had reported a “loss of power.”
This was the third time that checks have been ordered since October 2022. An Indian Army aviation ALH MK IV variant helicopter had crashed near Migging in Arunachal Pradesh in October, killing all five on board.
