Snowmobile amphibian A-3

Designed for the transport of goods and passengers by water in small shallow rivers, in winter on snow and ice in off-road conditions, and also in the off-season on floating or broken ice (autumn and spring ice ).

Amphibians were used to deliver mail , provide medical assistance to residents of remote settlements, during rescue operations and in the border troops of the USSR .

A-3 amphibian snowmobiles were designed in 1961 by a group of inventors under the guidance of engineer Gleb Vasilievich Mahotkin. Tests of the first sample took place in 1961 at the Istra Reservoir .

In 1962, the first copy was put into trial operation. At the same time there were improvements and improvements to the project. According to the results of tests on serial samples, a redan consignment note was installed , which facilitates access to planing . In 1964, the serial production of boats was launched, after six months, about a hundred amphibians had already been built.

The creation of the A-3 snowmobile amphibian was awarded with the VDNH awards in 1965 . Design Bureau of A. N. Tupolev received a first degree diploma, project managers: G. V. Mahotkin - gold medal, V. M. Tatarinov - silver, A. D. Vorobyov, V. V. Merkulov and V. T. Zhevakin - bronze .

The A-3 snowmobile could be operated both in summer and in winter, and during off-season (spring - summer, autumn - winter), when other equipment cannot be used.

A-3 amphibian snowmobiles were demonstrated in Finland , Sweden , Japan , Italy , Iraq , Chile , Canada , Brazil , Kuwait , in the socialist camp countries, and were exported to a number of countries.

A-3 were built at two aircraft factories of the USSR ( Transcarpathian Engineering Plant ), in total about 800 copies were built. A-3 amphibian snowmobiles were actively operated until the end of the 1980s, and individual copies continue to operate in the 2010s. in remote inaccessible areas .

The hull is metal , riveted , streamlined. The frame consists of a transverse and longitudinal power sets, to which the skin is attached. The sliding cover of the bottom is made of polyethylene and fiberglass sheets glued on the outside. Polyethylene is additionally bolted along the circuit.

The case is divided into three compartments:

- bow , it holds the anchor , there is an autonomous interior heater (in the winter season, runs on liquid fuel), as well as luggage;

- cabin with driver's seat and one passenger seat;

- Salon for four passengers, seats can be dismantled to accommodate cargo (luggage).

The cabin was closed by two wings on the sides (like an airplane lamp ).

In the aft part of the hull, a star-shaped aviation air-cooled piston engine with a pushing propeller was installed under the fairing. An oil tank was located in the stern, the engines had a dry sump lubrication system .

On the early-release planes stood the M-11FR engine with a capacity of 160 liters. from. (used on Po-2 aircraft and others) , during the production process they switched to AI-14 family engines with a capacity of 260 liters. from. (aircraft Yak-12 , Yak-18 ; helicopters Ka-26 , etc.) . Compared with the M-11FR, the power of the AI-14 aircraft engine was excessive, but the engine could not work at full power (not at full speed), which increased its engine life .

350 liters of aviation gasoline were poured into the fuel tanks located along the sides of the cabin. Fuel reserve allowed to overcome:

- on loose snow with 650 kg of cargo on board - up to 500 km;

- on water with 300 kg of cargo on board - up to 200 km.

The mover was a pushing propeller with flaps , which increased traction at low speed. In a number of instances, a twin (not coaxial ) propeller is used for the same purpose.

The course control was carried out by two vertical air rudders mounted on keels along the sides in the stern of the boat. Keels and air wheels were also a guard of the propeller. When the boat was sailing at low speed in a displacement mode (the feed “ sagged ” at the same time), the steering planes were partially immersed in water, which facilitated maneuvering and reduced circulation . The lower edges of the rudders facilitated a turn on the ice. The steering surfaces deviated in different directions worked as an aerodynamic brake . Thanks to this arrangement, the minimum turning radius in the snow did not exceed 6 meters, and the diameter of the circulation on the water was 20 meters.

The maximum speed on water reached 80 km / h .

The maximum speed in snow or ice reached 100 km / h .

Aerodynamics of the nasal tip contributed to the fact that the oncoming air flow was directed under the bottom, creating a screen effect . At high speed, the machine seemed to rise above the surface, the resistance to movement decreased, and the speed increased. The low specific load on the specially profiled bottom allowed the A-3 to glide on snow and water with the lowest possible resistance and move on broken ice and shallow reservoirs up to 5-10 cm deep. The car passed deep snow and ice at high speed, without prejudice to passenger comfort .

The streamlined body shape, the absence of protruding parts, not only reduced the resistance to movement, but also allowed the car to pass through the bush and through a rare forest.

The airboat could be towed by a truck on a snowy road at a speed of no more than 40 km / h.

• A-3 amphibian snowmobiles were used in the search and rescue service of the cosmonaut corps .
• The amphibian snowmobile of smaller sizes and masses was ordered by the Secretary General of the CPSU Central Committee L. I. Brezhnev . After reviewing the A-3, he asked for hunting to make him something similar, but smaller in size. An amphibious snowmobile project was prepared, weighing 400 kg, 4.5 m long and 1.8 m wide. Four-seater with 35 liter engine. from. developed in snow and water at a speed of 40-50 km / h. In total, three copies were built: two were transferred to the Zavidovo State Hunting Reserve , the third was used at the base in Dubna for testing purposes.
• A-3 amphibians were used as carriers of movie equipment on the set of Sergei Bondarchuk 's film “ War and Peace ”.
• In 1994, Arthur Chilingarov proposed the original design of a new generation of snowmobile amphibians, designated AC-2 . When creating the AC-2, the experience of creating and operating the A-3 was used.
• A-3 amphibian snowmobiles are presented at the exposition of the UMMC Automobile Technology Museum ^[1] .

• Aerosled "North-2"

• Snowmobile amphibian SKB A.N. Tupolev A-3
• Options A-3
• Snowmobile company "Tupolev"