The Kamov Ka-25 (NATO reporting name "Hormone") is a naval helicopter, developed for the Soviet Navy in the USSR from 1958.

Construction was of stressed skin duralumin throughout with flush-riveting, as well as some bonding and honeycomb sandwich panels.

The undercarriage consisted of two noncastoring mainwheels with sprag brakes attached to the fuselage by parallel 'V' struts with a single angled shock absorber to dissipate landing loads, and two castoring nosewheels on straight shock absorbing legs attached directly to the fuselage either side of the cockpit which folded rearwards to reduce interference with the RADAR, all wheels were fitted with emergency rapid inflation flotation collars.

Yaw was through differential collective which has a secondary effect of torque, an automatic mixer box ensured that total lift on the rotors remained constant during yaw maneuvers, to improve handling during deck landings.

Optional extras included fold up seats for 12 passengers, rescue hoist, external auxiliary fuel tanks or containers for cameras, flares, smoke floats or beacons.