Kamov Ka-31

Ka-31
Ka-31 in 2005
Role	Airborne early warning and control
Manufacturer	Kamov
First flight	1987
Introduction	1995
Status	In service, In production
Primary users	Russian Navy Indian Naval Air Arm People's Liberation Army Navy
Produced	1985-present
Number built	>35
Unit cost	$23 million (1999 rates)
Developed from	Kamov Ka-27

The Kamov Ka-31 (NATO reporting name 'Helix') is a military helicopter 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 an AEW, on sea.

The Soviet Navy selected the tested 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). So they were all mated in 1980 and the design was known as 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.