The Government of India cleared the proposal for procuring an additional ten Kamov Ka-31 Airborne Early Warning (AEW) helicopters for aircraft carrier operations and deployment on various warships. The decision was taken at a meeting of the Defence Acquisition Council (DAC). The Indian Navy had first ordered four Ka-31 AEW helicopters in 1999 with a further five in 2001. The first batch entered service with the Indian Navy in April 2003, the second batch in 2005 plus another five in 2013. INAS 339 ‘Falcons’ operates the type, with a fleet of 14 helicopters based at INS Hansa in Goa.
Optimised for AEW operations from major surface combatants, Kamov JSC which is based in Moscow, began development of the Ka-31 AEW naval helicopter in 1980 with the first flight taking place in 1987. Powered by twin Klimov TV3117VMAR turboshaft engines (rated at 1,633 kW each), essential mission of the helicopter is long-range detection of airborne threats including fixed-wing aircraft and helicopters. Surveillance, target tracking, and transmission of target data to command posts is carried out onboard the helicopter, thereby increasing the combat efficiency of associated naval units concerning interception of aerial threats plus Over-The-Horizon (OTH) strikes against hostile units.
Airframe of the Ka-31 is based on the proven Kamov Ka-27 helicopter which has co-axially mounted contra-rotating main rotors. The distinctive antenna of the AEW radar either rotates when operational, or remains folded and stowed under the fuselage. The Ka-31 has a maximum take-off weight of 12,200 kg, the operating altitude being up to 3,500 m, with a patrol speed of 100km/h and operational range, with the antennas in the stowed position, of 600 km. The mission duration is 2 hours 30 minutes.
The flight deck of the Ka-31 helicopter is wider than that of the Ka-27 and accommodates the pilot and navigator in an armour protected cockpit. The navigation suite includes a Kronstadt Kabris 12 channel Global Positioning System (GPS), digital terrain mapping, ground-proximity warning and obstacle approach warning. In IN service, the helicopter has an Abris GPS system featuring a 12 channel receiver with option to employ Differential GPS references, designed by the Kronstad itself. The key sensor, its E-801M Oko (‘Eye’), AEW radar, was developed by the Nizhny Novgorod Radio Engineering Institute, the 6m² radar antenna stowed flat against underside of the fuselage until deployed. The navigator switches on the radar system and the antenna then extends, turning through 90° from the horizontal to the vertical plane. In operation, the antenna rotates at 6 rpm. Once the navigator has switched the radar system to operational mode, the system works autonomously, the navigator monitoring the target observation on a display.