Aviation of World War II

DF (Douglas Flying boat). First flight - September 24, 1936. The passenger flying boat was an all-metal cantilever twin-engine high-wing aircraft with a semi-monocoque fuselage with a smooth skin. Passengers were accommodated in four separate cabins, each with eight seats or four berths. Each passenger compartment had four windows - two on board, two of which served simultaneously as emergency hatches. All compartments were connected by a common corridor in the center of the boat. In the event of a hole, the cabins were isolated from each other by removable partitions.

Auxiliary floats to reduce aerodynamic drag were made semi-retractable. After takeoff, the racks with floats were folded along the wing towards the fuselage. The tail unit was carried out according to the classical scheme. All rudders were equipped with trimmers.

The power plant consisted of two Wright SGR-1820-G2 "Cyclone" radial engines with three-blade metal variable-pitch propellers.

A total of 4 DF boats were produced - 1 prototype and 3 in a series, two were acquired by the Japanese to study "advanced experience in world aircraft construction" , this experience was used by the Japanese when building their own Kawanishi H8K , and 3 and 4 copies were acquired by the Soviet Union.

The third and fourth boats, built later than the Japanese ones, differed slightly from them and were designated by the company as a modification of the DF-195. Disassembled, they arrived in Leningrad in the spring of 1937. Since the planes were intended for the Polar Aviation Administration of the Glavsevmorput, they received numbers N205 and N206. In May, S. A. Levanevsky surpassed the first DF for testing in Sevastopol. The tests were carried out under the auspices of the Research Institute of the Civil Air Fleet, but polar pilots flew. In Sevastopol, two American flying boats, the DF and S-43 of the Sikorsky firm, were almost simultaneously evaluated. The vehicles quickly passed the entire program, which included the removal of flight characteristics, including long-range flights, tests of on-board equipment and a study of their seaworthiness. The Douglas boat was highly appreciated.

Compared with the outdated Dornier Val seaplanes then operated by polar aviation, it represented a completely new stage in the development of hydroaviation, not only significantly surpassing its predecessors in flight data, but also providing the crew with comfort and safety.

In addition, modern technologies and materials used in the US aircraft industry were of great interest to our specialists. From this point of view, DF was an excellent example of American industrial excellence.

Already in July 1937, the first DF, H-206, was transferred to the Yenisei air group. He began flying on the Krasnoyarsk - Dudinka line, carrying passengers and cargo. But in September, N206 was hastily removed from the track and used in the search for the missing crew of Levanevsky. The latter, on the N209 aircraft, converted into a civilian version of the DB-A four-engine bomber, tried to fly to the United States through the North Pole, but disappeared on the route. Many planes, both Soviet and foreign, were attracted to the search for N209, but they did not find anything. The work was carried out until winter, so the DF was no longer used on the lines that season. The following year, American boats were already regularly engaged in transportation in Siberia. In May 1939, the N206 was transferred to the Lena air group. The H206 was soon followed by a second car, the H205. Both of them were operated on the Lena in the 1940 season. In April 1941, the Lena line was transferred from the polar aviation to Aeroflot. In May, the Yakutsk Air Group of the Civil Air Fleet received part of the aircraft from the polar explorers, including both DFs. There they were caught by the war.

The summer navigation of 1941 for the Douglases began unsuccessfully. The flying boat N-205 in June 1941 crashed while landing at the Yakutsk hydroport, and the second, based at the Zhataysk hydroport, where it was serviced by a brigade of A.E. Ponomareva, flew safely and with a heavy load on this navigation, and throughout the war.

American aircraft continued to fly in the same places, but with an ever-increasing load due to the transfer of part of the aircraft to the front. In 1943, DF fulfilled the transportation plan by 209%.

After the termination of the operation of the Alaska-Siberia ferry route in March 1946, the 14th transport squadron of the Yakutsk Civil Air Fleet Directorate was again manned and airplanes. The list of aircraft assigned to the squadron also included the Marine Douglas under the name DG-1 with side No.3.18.

In the summer of 1946, the flight biography of this unique machine ended. Having worked out its resource, the last landing "Sea Douglas" made on the White Lake near the Yakutsk airport.

Photo	Description
	Схема Douglas DF-195
	Douglas DF-195 H-205 в СССР

March 27, 2019.

The photo above is a typical picture of the Soviet north - empty barrels of fuel and lubricants scattered everywhere ...

April 01, 2019.

There was a hope that the clean-up work "to the last destroyed barrel" will be financed and carried out ...

Bibliography

• "Encyclopedia of military engineering" /Aerospace Publising/
• "American warplanes of World War II" /under cor. David Donald/