Shipboard operations with the Ka-10 showed the necessity to start the construction of a new rotary-wing machine capable of lifting greater loads and less restricted by weather conditions. In 1950 AV-MF wrote an outline requirement for a larger two-seat helicopter with an enclosed cabin and much greater endurance.
These requirements were met by the Ka-15 which, like its predecessors, featured the co-axial layout. It was a two-seat helicopter with side-by-side seating for the pilot and a mission equipment operator or a passenger.
The rotor hubs and blades were scaled up but compared with Ka-10M, the only significant change was low-density foam filling the blades between ribs and taper of blades towards the tip.
The airframe was welded steel tube, with a covering of ply or dural removable panels and thin plastic glazing and sliding side doors round side-by-side cockpit ahead of rotor, with the engine behind.
The powerplant was a 225hp AI-14V air-cooled radial engine installed at the center of the fuselage, but towards the end of 1960, most Ka-15Ms were given uprated 275hp AI-14VF engines. The engine was mounted with the crankshaft horizontal, driving a cooling fan, 90 degree angle drive to the rotor via over-running clutch, and DC generator starter. From the engine to tail was of stressed-skin dural construction, with a fixed tail comprising braced tailplane and two endplate fins toed in at front (parallel on some Ka-15s), with pedal-driven rudders for yaw control.
The Ka-15 made its first flight on April 14, 1953 at the hands of test pilot D.K.Yefremov. State acceptance trials were completed in 1955, and next year the helicopter entered production at aircraft factory No.99 in Ulan-Ude.
Most fitted with two main and two nose landing wheels, plus tail bumper. The nose wheels were castoring and the main wheels were braked. At least one had pontoons and one with three skis.
AV-MF used substantial number for liaison, ship-based recon and dual Uka-15 for training. Ship trials in 1954 included dripping sonar, but it was unable to carry the equipment needed for ASW missions. The leadership of the Soviet Navy ordered a fly-off between the Ka-15 co-axial helicopter and the Mil Mi-1 single-rotor helicopter, during which both types operated from the cruiser "Mikhail Kutuzov". By virtue of its small size and manoeuvrability the Ka-15 successfully performed take-offs from and landings on the ship's small helipad even in sea state 6 conditions. Conversely, the Mi-1 was considerably hampered by its long tail boom and tail rotor and could not operate when air turbulence and pitching and rolling motion of the ship were present. The results of the fly-off finally convinced the Navy that choosing the co-axial layout for a shipboard helicopter was the right decision.
The ASW version the Ka-15 was fitted with two RGB-N sonobuoys or with the SPARU-55 automatic airborne receiver unit. One of such helicopters dropped sonobuoys in the designated part of a sea, the other received information from them about the presence or absence of a submarine. Once a submarine was detected, a third Ka-15 equipped with the OPB-1R sight and two 50-kg depth charges entered service. The first units equipped with Ka-15 helicopters were formed in 1957-58. In 1958 work commenced on equipping the destroyer "Svetly" (Project 57) with a helipad. In 1960-1961 the Navy took delivery of eight Project 57 ships featuring helipads, support equipment for helicopter operations and accommodation for pilots and maintenance personnel.
The Ka-15 evolved into a number of specialized versions, including the multi-purpose Ka-15M, the UKa-15 dual-control trainer version and the four-seat Ka-18. In each case prototype construction began at factory No.82 in Tushino and was completed at the OKB's own experimental shop near Ukhtomskaya railway station.
The Ka-15 and its versions remained in service for almost 20 years. Between 1958 and 1963, rotor blades of new design were developed, tested and introduced on the Ka-15M and the Ka-18. They were made of composite materials which improved the lift/drag ratio of the rotor and extended the service life of the blades. In 1958-59 test pilot V.V.Vinitsky established two world speed records on the Ka-15M (5 May 1959 170.455km/h over 500km). The Ka-15 marked the beginning of co-axial helicopters operations in the Navy and Civil aviation, the Soviet state airline. As was universally acknowledged, V.B.Barshevsky, M.A.Kupfer, N.N.Priorov, A.J.Vlasenko and D.K.Yefremov made major contribution to the development of the Ka-15.
From 1958 civil Ka-15M used for many roles including ag-spraying; Ka-15S equipped to carry two external stretchers.
The NATO reporting name for the Ka-15 is Hen.
Engine: 1 x AI-14V, 188kW / 225 hp
Rotor diameter: 9.96m
Fuselage length: 6.26m
Max take-off weight: 1370kg
Empty weight: 968kg
Internal payload: 364kg
Max speed: 155km/h
Service ceiling: 3050m