The Kamov Ka-26, which has the NATO codename Hoodlum, was announced in January 1964 as a light commercial helicopter with twin-turbine powerplant and a design easily convertible to meet the requirements of several roles. The primary task envisaged for the Ka-26 was agricultural.
The design team was headed by deputy chief designer M.A.Kupfer; Yu.I.Petrukhin was the leading designer and V.S.Dordan the leading engineer in charge of the flight tests. Kamov opted for its standard co-axial contra-rotating twin rotor configuration, powered by a pair of 325hp / 242.5kW Vedeneev M-14V-26 radial piston engines. To leave the area under the transmission and rotor assemblies free for the payload, the engines were installed in pods at the ends of shoulder-mounted stub wings, the engines and transmission being connected by drive shafts with flexible couplings.
The fuselage forward of the stub wings is a minimal pod with the crew cabin at the front, while the glassfibre tail unit is carried on twin booms and has conventional flying controls.
The greater weight of the piston engines units compared with turbines has been compensated by the use of lightweight materials in the airframe. In the Ka-26 helicopter the Kamov OKB made its first large-scale use of parts and subassemblies made from composite materials. Each of the interchangeable rotor blades is made of plastic, and weighs only 25kg; and much of the fuselage is made of aluminium panels sandwiched in glassfibre. Composite rotor blades had a 5000-hour service life.
The first prototype flew on August 18, 1965 flown by test pilot V.V.Gromov, followed by a small pre-series batch and the first production Ka-26 was flown during 1966. State trials were successfully completed in the autumn of 1967. Production was launched in the town of Kumertau at a factory which had been purpose-built in 1962. The Kumertau Aircraft Production Association continued production of helicopters bearing the Kamov emblem.
The design leaves the area under the engines and on the centre of gravity free for the payload. For agricultural work a 900kg hopper can be fitted, the load being spread by spray-bars or dust-spreaders under the hopper and aft of the tail assembly. For passenger operations the Ka-26 can be fitted with a detachable pod for six passengers on tip-up seats, and for freight work this pod can be used to carry up to 700kg.
The fully enclosed cabin has with door on each side, and is fitted out normally for operation by single pilot with a second seat and dual controls optional. The cabin is warmed and demisted by air from a combustion heater, which also heats passenger compartment when fitted. An air filter is mounted on the nose of the agricultural version.
A geophysical survey version carries a large hoop aerial around the fuselage, an electro-magnetic receiver bird (towed beneath the helicopter on a cable), and pulse generating equipment inside the cabin.
As an air ambulance, the Ka-26 can carry two stretcher patients, two seated casualties and a medical attendant. A winch, with a capacity of up to 150kg, enables it to be used for search and rescue duties. Ka-26s used in this role in Russian coastal areas are each fitted with three large inflatable pontoons, to permit operation from water. During tests, the hoist has been used to tow boats in Sea State 5 conditions.
When operating as an agricultural sprayer, the Ka-26 originally discharged its chemical payload at 1.5-12 litres/s. The rate of discharge in a dusting role was 1.5-12kg/s. Up to 120 ha could be sprayed during each flying hour at the rate of 50kg/ha. As a duster, 140 ha could be treated at the same discharge rate. 50 ha could be top-dressed with chemical fertilisers each hour, at a rate of 100kg/ha. These work rates were improved substantially by the introduction of an atomiser for liquid chemicals in 1978, followed by a centrifugal spreader for granular chemicals and dust in 1979. To protect the pilot against toxic chemicals in the agricultural role, the cabin is lightly pressurised by a blower and air filter system.
The Ka-26 was the first Soviet helicopter to be certificated in accordance with US FAR 29 airworthiness regulations. It was also the first Soviet helicopter to be sold abroad on a commercial basis; the Ka-26 was exported to 17 foreign countries. For more than 30 years it has been doing its job with dignity. The total flying hours amassed by the type amount to 2,907,000 hours by 1982, and in 1980 and 1982 the Ka-26 established five world records.
Six Ka-26's were ordered by an operator in Southern England in April 1967, the first order ever placed by a British customer for an aircraft designed and built in the USSR.
Rolls-Royce and Kamov signed an agreement to provide five Rolls-Royce RTM322 engines for the new KA-62R due to fly in 1993. The KA-62R was designed to carry some 14 passengers as a multi-purpose utility aircraft.
The Ka-26SS was a no-tail-rotor (NOTAR) technology testbed.
816 Ka-26 were built between 1968 and 1977.
In total 850 were built.
Engines: 2 x Vedeneev M-14V-26, 325 shp / 239kW.
Rotor diameter: 42 ft 8 in (13.00 m) each.
Fuselage length: 25 ft 5 in (7.75 m).
Fuselage width: 3.64m
Rotor disc area: 1,4287 sq.ft (132.73 sq.m).
Weight empty : 4454.1 lb / 2020.0 kg
Gross weight: 7,165 lb (3,250 kg).
Useful load: 900 kg.
Max speed: 160 kph.
Max cruising speed: 93 mph (150 kph).
Service ceiling: 3000m
Typical range: 250 miles (400 km) with 7 passengers.
Accommodation: Crew of 1 or 2 and up to 7 passengers.
Engine: 2 x Rolls-Royce RTM322. Pax cap: 14.