SM-903 scale-analogue Ekranoplan for the Lun program 3D print model

Herewith a 3D printable model of the SM-903 Ekranoplan, as it was developed by the CHDB (Central Hydrofoil Design Bureau)in the 1980's. The model has been created in Solidworks, I've included STEP and IGES files, next to seperate STL files for all printable parts. All parts are sized to be printed on print beds of 30x30cm upwards and of course can be resized accordingly. In the standard size the assembled model is 654 x 338 x 145 mm.

The Orlyonok’s started their operational routine in the Soviet Navy in the early 1980’s. At the same time, the project 903 was started, which was eventually going to lead up to the infamous “Lun” and “Spasatel” ekranoplans. This project was run by Kirillov, one of the senior engineers in the CHDB at the time. As has been common practice with the two previous large Ekranoplan programs, a ‘small-scale’ testing vehicle was designed for the project 903, which was supposed to be built and tested before the production of the final large-scale machine. For the Korabl Maket, these were the SM-5 and SM-8, for the Orlyonok (Project 904) this was the SM-6. For the project 903, this was the SM-903.

The SM-903 was a vehicle which possessed the same basic aerodynamic and hydrodynamic layout as the Lun, excluding it’s famous weaponry and radar installation. It was an exact scaled down version, powered by two, instead of eight, Al-25 turbofan engines. Both engines were equipped with the same type of swayable nozzles to direct the efflux under the wings for take-off, to provide power-assisted-ram. It was also equipped with an identical shaped (but scaled down) central hydroski. The vehicle would have had a take-off weight of about 10 tons.

After finishing the design work on the SM-903, plans were made for the testing program, and the usage of this vehicle for dedicated crew-training purposes after the testing program had been finished. The next line of actions is unclear, but politically there was a change of heart to the 903 program execution. Whilst the design of the SM-903 was finished and offered up for budgetary approval, the whole program was scrapped in favor of the design of a dedicated training ekranoplan, which would eventually lead to the actually built Strizh two-seater Ekranoplan. The project 903 was continued and the Lun and Spasatel were actually built, without the SM-903 ever leaving the drawing board.

There is little extra data available on this Ekranoplan type, and only a sideview and topview are publicly available to demonstrate what it would have looked like. This 3D model is based on those two available views and is an exact representation. Sparce details have been filled in by carefully taking design features from the Lun & Spasatel, which are basically scaled up versions of the same vehicle.

The model includes many separate features, all flaps & flight control surfaces, nozzles and hydroski can be moved and mounted in any desired position. The model does not include panel lines but does include all doors & access panels.