The Ka-31 was based on the Ka-27 and has many optical similarities to it. One of its special features is the large antenna of the early warning radar with a length of 6 m. The antenna is rotating if the radar is used, to prevent interferences of the radar, it has a retractable undercarriage, if the antenna is not used it can be folded and stowed under the fuselage. The helicopters cruise speed while using the radar is 100 km/h. The maximum range against a convetional flying object is about 150 km and against ships up to 200 km. The radar is able to track up to 40 targets.