When the Fi-156 purchased in 1940 along with other samples of German aircraft was studied by Soviet specialists, they were surprised to find that the wing profile with its slotted ailerons, flaps and slats is no different from the R-11 profile developed by Soviet engineer P.P. Krasilshchikov .

In 1940, the USSR developed (designer O.K. Antonov) the OKA-38 communication aircraft, which was an almost exact copy of the Fi-156C. The aircraft was planned for use as a liaison and ambulance. The introduction of the aircraft into mass production was interrupted by the outbreak of war.

The wing is two-spar, wooden with a strut made of teardrop-shaped steel pipes. The plumage is also braced, wooden, in plan it was somewhat different from the "Shtorch".

The aircraft was equipped with an in-line 6-cylinder air-cooled engine MB-6 (instead of the 8-cylinder V-shaped inverted "Argus" on the "Storch"), which appeared in the late 30s as a licensed reproduction of the French engine Renault. Propeller - wooden monoblock fixed pitch. From the comparative table it can be seen that, other things being equal, the length of the run and run of the Soviet "Aist" increased three and two times, respectively. In my opinion, the reason is that the longer inline engine did not allow the propeller to be close to the wing surface and provide optimal air flow conditions for maximum lift.

The data of the OKA-38 and Shtorkh aircraft are based on the results of tests at the Air Force Research Institute.

After the war, taking into account the operating experience of the Shtorkh, the Yakovlev Design Bureau created the Yak-12. Several modifications of the aircraft were produced with different engines and the number of crew members (from 2 to 4). The table for comparison shows the data of the Soviet post-war "Aist" with a crew of 3 people and an engine power of 260 hp.

Bibliography

• Luftwaffe Aviation /V.N. Shunkov./
• History of aircraft designs in the USSR 1938-1950. /Shavrov V.B./
• Fizler Fi 156 "Storch" aircraft /Vladimir Kotelnikov/
• Aircraft OKA-38 "Aist" /Vyacheslav Kondratiev/

December 4, 2022.
Please note that for the Yak-12, the engine length of which is shorter, the mileage distance was halved compared to the OKA-38, and the wing allowed to land by parachuting method ...
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ANT-25-1 crew of Gromov in America, July 14, 1937

July 11, 2020.
As we understand, OKA-38 is an abbreviation for Oleg Konstantinovich Antonov, by analogy with the accepted fashion of the 30s. This is how the aircraft of Andrey Nikolaevich Tupolev received their names.
Once again about the confusion with Antonov's name. Any schoolboy knows, at least he used to know, that the record-breaking ANT-25 aircraft that crossed the North Pole with Chkalov, Belyakov and Baidukov is the aircraft of Andrey Nikolaevich Tupolev. On the second aircraft ANT-25-1, Gromov, Yumashev, Danilin, having taken off on July 12, 1937, also reached America through the North Pole, having overcome 10,200 km.
However, after reading the book Bf 109E/F vs Yak1/7 Eastern Front 1941-42, by our respected authors Dmitry Khazanov and Alexander Medved, was extremely surprised. It was a sinful thing to think that I translated it badly from English :-). It states that the ANT-25 is an ANTONOV aircraft!
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