The Bartini Stal-6, was a single-engined experimental aircraft designed, built and tested in the

USSR The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nationa ...

from 1930.

Development

After joining the OOS (''Otdel Opytnogo Samolyetostroeniya'' - section for experimental aircraft construction), Bartini was appointed leader of his own design group, where he attempted to design the fastest, most advanced machine possible. After submission of his proposal to TsKB (''Tsentrahl'noye konstrooktorskoye byuro'' - central construction bureau), there was an 18-month delay before permission was given to proceed. The major component of the Stal-6 was the V-1570

Curtiss Conqueror The Curtiss V-1570 Conqueror was a 12-cylinder vee liquid-cooled aircraft engine. Representing a more powerful version of the Curtiss D-12, the engine entered production in 1926 and flew in numerous aircraft.Gunston 1989, p. 46. Design and de ...

steam-cooled

V-12 engine A V12 engine is a twelve-cylinder piston engine where two banks of six cylinders are arranged in a V configuration around a common crankshaft. V12 engines are more common than V10 engines. However, they are less common than V8 engines. The fir ...

, this was closely cowled and defined the maximum sectional area of the fuselage, which transitioned smoothly from nose to tail with a flush cockpit canopy. The manually retractable undercarriage consisted of a single main-wheel and skids at the wing-tips. To eliminate the drag of radiators the wings were double skinned with ' enerzh-6' ( stainless steel), from the leading-edge back to the main-spar, to form the surface-evaporation radiators for the steam cooling system of the engine. Flight testing began in the autumn of 1933 piloted by A.B.Yumashyev and P.M.Stefanovskii, revealing exceptional performance and setting a

Soviet The Soviet Union,. officially the Union of Soviet Socialist Republics. (USSR),. was a transcontinental country that spanned much of Eurasia from 1922 to 1991. A flagship communist state, it was nominally a federal union of fifteen nation ...

speed record, but severe problems with the steam cooling system as well as the bad view from the cockpit were insurmountable. The need for steam cooling was soon to be negated by the widespread availability of

ethylene glycol Ethylene glycol (IUPAC name: ethane-1,2-diol) is an organic compound (a vicinal diol) with the formula . It is mainly used for two purposes, as a raw material in the manufacture of polyester fibers and for antifreeze formulations. It is an odo ...

-based coolants, which had a better

specific heat In thermodynamics, the specific heat capacity (symbol ) of a substance is the heat capacity of a sample of the substance divided by the mass of the sample, also sometimes referred to as massic heat capacity. Informally, it is the amount of heat t ...

and a much higher boiling point.

Variants

Stal-8

The Stal-8 was a fighter developed from the preceding Stal-6 experimental aircraft. The

steam-cooled V-12 engine was replaced by an M-100A (licence-built

Hispano-Suiza 12Y The Hispano-Suiza 12Y was an aircraft engine produced by Hispano-Suiza for the French Air Force before the Second World War. The 12Y became the primary French 1,000 hp (750 kW) class engine and was used in a number of famous aircraft, i ...

BR), this also was closely cowled and defined the maximum sectional area of the fuselage, which transitioned smoothly from nose to tail except for the cockpit which was enlarged to improve the view of the pilot. Two

7.62mm The 7.62 mm caliber is a nominal caliber used for a number of different cartridges. Historically, this class of cartridge was commonly known as .30 caliber, the imperial unit and customary unit equivalent, and was most commonly used for i ...

ShKAS The ShKAS (Shpitalny-Komaritski Aviatsionny Skorostrelny, Shpitalny-Komaritski rapid fire for aircraft; Russian: ШКАС - Шпитального-Комарицкого Авиационный Скорострельный) is a 7.62 mm calibre ...

machine-gun A machine gun is a automatic firearm, fully automatic, rifling, rifled action (firearms)#Autoloading operation, autoloading firearm designed for sustained direct fire with rifle cartridges. Other automatic firearms such as Automatic shotgun, a ...

s were to be fitted in the top decking over the engine, synchronised to fire through the propeller. Construction of the prototype, with steel tube fuselage covered with plywood skinning and steel tube built up wings, with the 'enerzh' double skinned surface-evaporation radiators forming the leading edge skin, back to the main-spars, was approximately 90% finished when the

Soviet Air Force The Soviet Air Forces ( rus, Военно-воздушные силы, r=Voyenno-vozdushnyye sily, VVS; literally "Military Air Forces") were one of the air forces of the Soviet Union. The other was the Soviet Air Defence Forces. The Air Forces ...

rejected the aircraft on grounds of vulnerability of the cooling system.

Specifications (Stal-6)

References

* Gunston, Bill. “The Osprey Encyclopaedia of Russian Aircraft 1875–1995”. London, Osprey. 1995.

External links