My favourite Russian helicopters are those designed by the Kamov design bureau, which specializes in helicopters with contra-rotating rotors, which don't require the tail rotor needed to counteract the torque created by a single main rotor. The tail rotor requires a significant amount of power, anywhere from 10% to 25% of the total, so a contra-rotating design is inherently more efficient, potentially allowing great lifting capacity and speed, and the lack of a tail rotor is also a significant benefit from the point of view of safety of people operating around the craft. Two different configurations of the Kamov Ka-226 Sergei light multi-purpose helicopter were shown, this one hauling some drums and another one with a rear cabin occupying the space behind the cockpit. The Ka-226 is an update of the Ka-26 "flying chassis" first delivered in 1965. The detachable cabin can be used for medical evacuation or transport of personnel, or other equipment can be fitted for agricultural or other commercial work.