Here's an actual drawing, again returning to postwar with the Stechovsky S-2 Moyevka and some of its developments;
Designed to replace the myriad of types in service after the end of the Second World War, namely the Li-2, Sieran sought to develop a new civil airliner taking advantage of experience gained in the war with building more advanced machines and engines as well as utilising 'new' technology such as the tricycle landing gear. Initially the fuselage was to have been pressurized however the equipment was not ready in time so the Government gave the go ahead to build a non-pressurized prototype.
The end result was the S-2A Moyevka, named after the noisy seabirds after the test pilots complained of excessive noise and vibration in the cockpit and cabin. The S-2A-1, as the prototype was designated, was also found to be rather heavy on the controls whilst the new Movich MSh-190c (formerly M-19, 190 refers to single row, 900hp) was found to be somewhat maintenance intensive, which was no surprise given the original design dated back to the MSh-175 which had been a developed version of the Pratt & Whitney R-1340 Wasp. The New engine was pushing the limits of the limits of the design hard and after spiraling engine trouble plagued the flight test program, the Government stepped in and forced Movich to abandon the engine and produce a more reliable engine that would later be known as the MSh-2120. This engine delayed the development of the S-2 and Ilyushin Il-14s were imported instead, eating away at the original market for the new plane.
By the time the S-2A-2 was ready with the new engines, the company had effectively missed the boat, with the Ilyushin type fulfilling the role it had been designed for.
Not all was lost however. With the Il-14s being locally produced in small numbers, Stechovsky had the opportunity to analyze the new design. The S-2 continued to be developed at the companies own expense in the hope of attracting Military or foreign orders for the type. A cargo version was developed which included a strengthened cabin floor and a large double cargo door in the starboard rear fuselage.
The passenger version was also further developed, with the delayed pressurization system installed and noise-dampening lining added to the cabin in an attempt to counter the loud internal noise. Another inclusion with this variant, dubbed the A-4, was a weather radar housed within a re profiled nose.
Even with these developments, the S-2A was proving to be a less than satisfactory machine. Whilst the MSh-2120 proved more reliable than the engine it replaced, it was incapable of providing power efficiently at high altitudes and as a result speed and ceiling suffered. The control problems had also not been resolved, the plane was hard to control in the pitch and pilots found the placement of the trim wheels awkward and hard to reach. Perhaps more serious, the aircraft was found to suffer unexpected loss of control at high angles of attack. The crash of A-1 on approach after a test flight almost killed the program.
During the lengthy investigation after the accident, it was discovered that when at high angles of attack, the aircrafts broad wings created sufficient turbulent air to disrupt the smooth airflow over the tailplane, effectively resulting in the tailplane becoming useless. This phenomena, later known as a deep stall, was still relatively unknown at this time and it took some time before the S-2B-1 emerged.
The B-1 was a radically redesigned machine from its predecessors. Most notably the tailplane was now fixed to the fuselage instead of the vertical tail in an attempt to provide more clean air over the tail surfaces during high angles of attack. Another significant change was yet another re-engining of the type, this time to the new Movich MSh-2240 engine that produced almost double the power of the old engines. This significantly improved the aircrafts performance, both in terms of speed and ceiling. Internally the fuel tanks had been enlarged to increase range and the cabin had again been fitted with even thicker sound proofing to quieten the space. The engine mounts too featured rubber blocks to reduce the vibration, another effort to increase the aircrafts comfort.
With sales still poor, Stechovsky decided to take another radical step in the design of the S-2 by lengthening the fuselage, primarily with the intent of increasing cargo and mail space though increased passenger seating was also offered. This version, the C-1, had an increased MTOW over its smaller siblings thanks to strengthened landing gear but it still suffered from a shorter range given the comparatively small wing. Otherwise the machine was considered reasonably effective at lifting heavier loads.
With both the B-1 and C-1, Stechovsky marketed aggressively in an attempt to get foreign sales for the aircraft which had by this point placed considerable strain on the company over its prolonged development and poor sales. The aircraft was positioned as being as effective as any European or American twin but with superior reliability and ruggedness available at a lower price point.
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More variants are to come along with liveries for the various versions. I am also pondering doing a turboprop conversion as a last attempt by Stechovsky to squeeze as much out of the airframe as they can.
In terms of crediting, these drawings feature a number of sections from both Eswubes and Kilmouses drawings of various types from this period, namely the Convair and Ilyushin families. However I have modified these quite a bit to produce a look I like so I am not sure how much is worth crediting given the nature of them.
Also, anybody want to help the strain and order some of these? xD
