Well with the forums down I got plenty of actual drawing done and worked on that concept of a Sieran built development of the Tupolev SB. I started out fairly close to the plane but I think now that there's nothing left of it! xD I changed a lot but I'm actually very happy with how they came out.
The idea of these planes also was that they were initially developed as airliners that saw some use as bomber leading up to conflict as they were fast and available. Again, a 12Y and a Movich MSh-190 (A Sieranian engine developed from a Sieranian clone of the Wasp engine that also powered many other aircraft interwar) powered aircraft were built for trials. The radial aircraft was chosen for mass production due to its rugged performance however a number of 12Y powered airframes saw service as high speed mail and passenger planes as they had a higher overall top speed (with some during the war converted into reconnaissance aircraft).
The bomber developments saw a machine gun installed in a swapped, glazed forward nose section and a removable panel in the aft fuselage for a flexible machine gun mount. At the time it was considered not important to have heavier firepower as the bomber was faster than both the Sieranian and Japanese fighters of the period.
I'm still working on the backstory and specifications for this aircraft so I'll update this post as I finalize them.
Also a final note, Korolev was a company made up of teams of differing designers. Many aircraft produced were put into production under the Korolev name though much of the design work was done by other companies. Korolev was one of two Sieranian aircraft manufacturers in the 1930s that operated in this manner (the other being known as SAF, an abbreviation of Sieran Aircraft Factories which owned most of the production and hangar facilities and was responsible for their development).
Now for some drawings.
Blank airliner versions (complete with specific model designation);
Blank bomber versions (complete with specific model designation);
Prototype airframes of the first production aircraft which undertook performance trials and testing at the two Army Aviation test facilities in west-central Sieran;
Bombers of a squadron based at Talovka airbase near Anadyr during 1937 in the then standard markings of overall drab green with grey undersurfaces and no unit markings beside aircraft tail number in flight. Flight leaders had white bands applied to the aft fuselage;
Airliners of Sieran National Airways, the state-owned and operated airline that primarily connected the many population centres of the interior where rail and sea connections were not available. Some of these aircraft would fly to local international ports such as Anchorage though they were better suited to shorter domestic hops. Seating was for 14 passengers and 3 crew.
Enjoy