New Delhi: Sometime over the next couple of months India and Russia will sign another defence contract for the supply of five Russian Kamov-31 airborne early warning helicopters. The acquisition is aimed at bolstering the capabilities of the Indian Navy to detect airborne and surface-based maritime threats.

The proposal was cleared by the Cabinet Committee of Security (CCS) at a meeting on Tuesday, according to defence ministry officials.

The Ka-31's airborne electronic warfare radar, mounted on its underbelly, can track 30-40 surface and air targets simultaneously.

The navy already has a fleet of nine Ka-31 helicopters, which are deployed on India's only aircraft carrier INS Virat and the Talwar Class guided missile stealth frigates of the navy.

They also operate from the navy's shore-based air stations.

Kamov-31
The Indian Navy's first batch of four Ka-31's entered service in April 2003. The second batch of five was delivered in 2005.

The surveillance range against a surface ship is typically 100km to 200km. The radar is capable of simultaneously tracking 40 targets. When the radar surveillance phase of the mission is completed the antenna is retracted to the storage position, which is flat against the underbelly of the rotorcraft .

The Ka-31 has a maximum take-off weight of 12,200kg with an operating altitude of up to 3,500m. The helicopter flies on patrol at 100km/h and the operational range with the antennas in the stowed position is 600km. The mission duration is two hours 30 minutes.

Operations with the Indian Navy revealed a major drawback of the aircraft, which was its limited endurance/range. So, state-owned Hindustan Aeronautics Ltd (HAL) was commissioned to experiment, and possibly adapt, a helicopter-to-helicopter refuelling system.

Also, in the Indian service, the aircraft received Abris GPS system featuring a 12-channel receiver and option to employ Differential GPS references.

The Indian Kamo-31's feature navigational equipment for digital terrain maps, ground-proximity warning, obstacle approach warning, auto-navigation of pre-programmed routes, flight stabilization and auto homing onto and landing at the parent carrier/base and information concerning the helicopter's tactical situation.