Lingering doubts over the reliability of the Hindustan Aeronautics Dhruv advanced light helicopter have led to the Indian navy opening a requirement for utility helicopters to other manufacturers.

The navy now has six Dhruvs in its fleet, but these have been plagued by maintenance and servicing woes, say industry sources. As a result, the service has issued a request for information to companies including Bell, Boeing, Eurocopter and HAL for helicopters that can perform anti-submarine warfare and communications roles.

The requirement, which is believed to be initially for around 60 aircraft, will replace Westland Sea Kings, HAL-built Chetaks and potentially some planned Dhruv orders. The new aircraft will become the service's main rotary asset and be based on its Godavari-class frigates.

Technical details have not been released, with the navy still fine-tuning its requirements. These will become clearer when a request for proposals is issued, with the defence ministry expecting this to take up to a year to prepare.

An order for a foreign helicopter would come as a major blow to HAL, which has been pushing for the increased acceptance and induction of the Dhruv throughout the Indian armed forces. There have been several issues with the design in the past, and the navy is now reportedly unhappy with the performance of its hingeless main rotor's folding blades.

Rectifying the problems appears to be high on HAL's priorities list, and the company has set up a dedicated maintenance, repair and overhaul facility that has helped lower the helicopter's line replacement unit failure rate. It is also improving the Dhruv, including through the integration of Turbomeca TM333 turboshaft engines, high-performance composites, advanced blade profiles for reduced noise, high speed and more efficient lift, and pressurised refuelling for quick turnarounds.

A weaponised version of the Dhruv that will be powered by the high performance Shakti (Ardiden) engine for high-altitude warfare is also being worked on, while HAL expects to complete detailed design work by year-end on a light combat helicopter variant that should fly in prototype form in the fourth quarter of 2008.

Source: Flight International