The Advanced Light Helicopter (ALH) DHRUV fleet operated by the Indian Navy and the Indian Coast Guard is scheduled for a significant overhaul focusing on a vital component, the Non-Rotating Swashplate Bearing (NRSB), reported Money Control web portal.

This move follows the findings of the Defect Investigation Committee set up after a crash involving a Coast Guard DHRUV on 5 January, which resulted in the tragic loss of three personnel. The committee identified that the NRSB played a crucial role in the accident due to its failure under strain.

The NRSB transmits flight-control inputs to the main rotor blades, making it an essential element in the helicopter’s control system.

The committee’s investigations revealed that the manufacturing process of the NRSB requires enhancement to increase its fatigue life, especially for helicopters operating in maritime environments. The Navy and Coast Guard DHRUVs routinely experience harsher operating conditions such as high salinity and frequent deck landings, which place greater mechanical stress on the component.

All 28 DHRUVs serving with the Indian Navy and Coast Guard will undergo this manufacturing upgrade to the NRSB to ensure enhanced durability and reliability.

The process of modification is planned to be carried out in batches, allowing the helicopters to be returned to service progressively. Officials anticipate that each helicopter will be handed back to the respective force’s fleet within approximately six months after the upgrades are completed.

This overhaul affects only the naval and Coast Guard variants of the DHRUV. The Indian Army and Indian Air Force fleets, which also operate DHRUVs, were grounded temporarily following the incident but have since resumed flights. Investigations confirmed that the NRSB issue leading to the crash does not impact these other fleets, given their different operational environments and usage patterns.

The grounding of all DHRUV helicopter variants for a period following the crash was a precautionary measure taken to safeguard personnel and equipment. The comprehensive review and subsequent recommendations by the committee reflect efforts to address the root causes and prevent recurrence.

Until recently, Hindustan Aeronautics Limited (HAL), the manufacturer responsible for the DHRUV production and maintenance, had not publicly commented on the investigation’s findings or the subsequent modification plans.

The scheduled overhaul of the NRSB is a critical step in restoring full operational capability to the Indian Navy and Coast Guard DHRUV fleets.

This upgrade not only enhances the safety of the helicopters’ flight systems but also strengthens operational readiness for maritime missions. By addressing this key vulnerability, the forces aim to maintain their reliability in demanding environments where these helicopters play vital roles in surveillance, search and rescue, and other naval operations.

Based On Money Control Report