The military's Dhruv Advanced Light Helicopter (ALH) fleet, grounded since January 2025 following a fatal crash in Gujarat, will remain out of action for at least three more months as investigators continue to determine the root cause of the accident. This extended grounding affects approximately 330 DHRUVs operated by India's three military services and coast guard, creating significant operational challenges while underscoring the priority being placed on flight safety over operational readiness.

Background of The DHRUV Grounding

The current grounding stems from a January 5, 2025 crash of an Indian Coast Guard DHRUV at Porbandar, Gujarat, which resulted in the deaths of two pilots and an aircrew diver. This prompted immediate safety concerns and led to the grounding of the entire fleet of Dhruv helicopters across all service branches. Investigations revealed that the crash was caused by a "swash-plate fracture," a critical component in the helicopter's transmission system.

This January incident marked the second fatal crash in just four months involving a Coast Guard DHUV near Porbandar. In September 2024, another DHRUV crashed into the Arabian Sea, also killing two pilots and an aircrew diver. These recent accidents are particularly troubling because they occurred after Hindustan Aeronautics Limited (HAL) had completed a critical safety upgrade on the military's DHRUV fleet following a string of accidents in 2023.

Previous Safety Record And Upgrades

The DHRUV has been involved in approximately 15 accidents during the past five years, raising serious concerns about its safety record. In response to earlier incidents, HAL initiated a comprehensive design review in 2023-2024, which led to the installation of upgraded control systems intended to improve airworthiness. The military's Dhruv fleet had been grounded several times in 2023 as well, due to what was described as a "nagging design issue".

Despite these upgrades being completed before the September 2024 and January 2025 crashes, the helicopters continued to experience critical failures, prompting the current more extensive investigation and prolonged grounding.

Technical Analysis of The Swash-Plate Failure: Understanding The Swash-Plate Assembly

The swash-plate is a fundamental component in a helicopter's control system. It functions essentially as the helicopter's "steering wheel," translating pilot inputs into movements of the rotor blades that control the aircraft's direction and attitude. When this component fails, pilots lose the ability to properly maneuver the helicopter, which can lead to catastrophic loss of control.

HAL Chief DK Sunil confirmed in February 2025 that a swash-plate fracture was identified as the root cause of the January crash. However, the investigation has been unable to determine precisely why this critical component failed. As HAL's chief explained, "The defect investigation committee (DIC) is looking at what caused the material failure and is expected to submit its report in three weeks". This timeline has since been extended as the investigation has grown more complex.

Fleet-Wide Inspection Findings

Perhaps most concerning is that a fleet-wide inspection conducted after the January crash revealed that some Navy and Coast Guard DHRUVs were experiencing similar problems – specifically, cracks in their swash-plate assemblies. These findings suggest a potentially systemic issue rather than an isolated failure. Investigators have hypothesized that the problem could be linked to sustained operations in saline environments, which might accelerate metal fatigue or corrosion in the aluminium alloy components.

Ongoing Investigation And Research

Hindustan Aeronautics Limited has broadened the scope of its investigation by partnering with the prestigious Indian Institute of Science (IISc) in Bengaluru to conduct thorough fatigue testing of the aluminium alloy used in the swash-plate assembly. This scientific approach aims to determine whether the material itself is failing under certain operational conditions or if other factors are contributing to the component's breakdown.

Scientific Testing And Analysis Process

The testing at IISc essentially puts the material through rigorous stress tests to evaluate how it performs under different loads and environmental conditions. HAL has provided IISc with samples of the raw aluminium alloy material that the swash-plate is manufactured from. This fatigue testing will help determine if the material's properties change over time, particularly when exposed to challenging operational environments like coastal regions with high salt content in the air.

Investigation Timeline And Committee Structure

A formal Defect Investigation Committee was established following the January crash, comprising experts from:

The Centre for Military Airworthiness and Certification (CEMILAC)
The Directorate General of Aeronautical Quality Assurance
Hindustan Aeronautics Limited

The IISc is expected to submit its findings by the end of April 2025, after which the DIC will incorporate this technical data into its comprehensive report, likely to be completed in May 2025. Following these reports, HAL estimates it will require at least another month to implement any necessary fixes and conduct fleet-wide inspections before the helicopters can safely return to service.

Operational Impact of The Prolonged Grounding

The extended grounding of 330 DHRUVs represents a significant setback for India's military and coast guard operations. The Dhruv helicopter serves as a workhorse across multiple mission profiles, including troop transport, search and rescue, and various tactical operations.

Strain On Alternative Helicopter Fleets

With the DHRUV fleet grounded, other military helicopters – specifically Mi-17s, Chetaks, and Cheetahs – are being overworked to compensate for the operational gap. This increased utilisation places additional strain on these alternative platforms and may accelerate their maintenance requirements and potential wear.

The Coast Guard, which operates 19 DHRUVs, has been particularly affected, having lost two helicopters and six crew members in similar accidents within just four months. These losses represent not only a reduction in operational capacity but also a devastating human cost.

Potential Solutions And Return To Service

The timeline for returning the DHRUV fleet to operational status depends entirely on the findings of the ongoing investigation. If the issue is determined to be solely related to material failure, the fix could be relatively straightforward – potentially involving replacement of the swash-plate assemblies with components made from improved materials or with enhanced resistance to environmental factors.

Possible Scenarios For Resolution: Three Potential Scenarios Exist:

If the aluminium alloy itself is found to be unsuitable for the operational environment, a simple material replacement with a more suitable material might resolve the issue.

If the issue can be addressed through enhanced inspection and maintenance protocols, HAL might implement fleet-wide checks that can be performed in the field, allowing for a relatively quick return to service.

The most complex scenario would involve a fundamental design issue requiring significant modifications to the transmission system. In this case, each helicopter's integrated dynamic system – including the transmission system, gearbox, and rotor hub – would need to be transported to HAL facilities for extensive rework. This would substantially extend the grounding period.

Conclusion

The prolonged grounding of India's DHRUV fleet illustrates the complex balance between operational requirements and flight safety. While the extended absence of 330 workhorse helicopters creates significant challenges for India's armed forces, the thorough approach to investigating the swash-plate failures demonstrates a commitment to addressing root causes rather than implementing temporary fixes.

The collaboration between HAL and academic institutions like IISc represents a scientific approach to solving a critical safety issue. As the fatigue testing and investigation continue, the findings will likely influence not only the immediate repairs needed to return the DHRUV fleet to service but also future design considerations for Indian military helicopters operating in diverse and challenging environments.

Until these investigations conclude and appropriate solutions are implemented, India's military and coast guard will continue to face operational constraints while other helicopter types shoulder the additional burden. The ultimate resolution of this issue will be a crucial test for HAL's engineering capabilities and the long-term viability of the indigenous Dhruv helicopter program.

IDN Report