Ka-31 (Helix) Russian Airborne Early Warning Helicopter

The Kamov Ka-31 (NATO reporting name 'Helix') is a military helicopter originally developed for the Soviet Navy and currently in service in Russia, China, and India in the naval airborne early warning and control role. As with all Kamov helicopters except the Ka-60/-62 family, the Ka-31 has co-axially mounted contra-rotating main rotors. The airframe of the Ka-31 is based on the Kamov Ka-27. One visually distinctive feature of the Ka-31 is the large antenna of the early-warning radar, which is either rotating or folded and stowed under the fuselage. The second is the reduction of the bulky electro-optical sensory suite beneath the cockpit. The landing gear retracts in order to prevent interference with the radar. The Kamov Joint Stock Company (then, Kamov DB), began development of the Ka-31 medium-weight naval helicopter in 1980 and the first flight took place in 1987. This development was the direct result of the cancellation of the shipborne Antonov An-71 AWACS aircraft. The An-71 was intended to be deployed on the Soviet Navy's first true aircraft carrier, Admiral Kuznetsov (then known as Tbilisi). The An-71 was cancelled in favour of the Yakovlev Yak-44. Though Yak-44 was in development (and not yet cancelled) at that time, the Soviet Navy wanted a stop-gap measure and began investigating other viable platforms to act as AEW at sea. The Soviet Navy selected the proven Kamov Ka-27 airframe. The Kamov Design Bureau was already in the process of developing the Ka-29. Nizhny Novgorod Radio Engineering Institute was working on a radar design to be used on the An-71; the same design was applied with changes for a rotary wing airframe. Integration was complete by 1980 and the helicopter was given the designation Ka-29RLD. The radar development took time and it was not until 1987 the first flight took place. The production version of the Ka-29RLD/-31 was very different from the Ka-29 from which it was derived.