Bolkhovitinov S (Sparka) High-Speed, Two-Seat, Twin-Engine Bomber Prototype Aircraft
Just two of the developmental Bolkhovitinov high-speed bombers were built by the Soviet Union during World War 2.
Authored By Staff Writer; Content ©www.MilitaryFactory.com
It wasn't just the British, Americans, Germans, and French that undertook special aircraft projects prior to World War 2 (1937-1945) for Soviet engineers were also hard at work on perfecting various types. The Bolkhovitinov "S" - or "Sparka" - was one such entry into the Soviet stable, originating in the pre-war period of 1937 and recorded a first-flight in 1940. Designed as a high-speed / light-class bomber, just two of the kind were built for the program.
One of the unique characteristics of the Sparka was its conjoined engine fit, coupling a pair of Klimov M-103 inline piston engines (960 horsepower output each) and these used to drive a pair of three-bladed contra-rotating propeller units at the nose. The inline engines allowed for a streamlined shape to be achieved and this produced a sleek airframe with the cockpit / crew area set over midships and aft. This section was noted for its long-running, greenhouse-style canopy (housing a standard operating crew of two). The wing mainplanes were set at midships as well and these were straight appendages mounted low with swept forward trailing edges. The tail unit was another unique characteristic of the design as a twin-rudder arrangement was used with horizontal planes set between the two fins. The tail planes were mounted atop the fuselage spine. The undercarriage was of a typical tail-dragger arrangement consistent with developments of the period. Light alloys were used throughout the aircraft's construction. Dimensions of the aircraft included a length of 43.3 feet and a wingspan of 45.2 feet. Gross weight was 12,460lb.
Proposed armament was 1 x 7.62mm ShKAS machine gun for the rear crewman (the gun positioned on a trainable mounting). This armament was revised at a later date to become 2 x 12.7mm UBT series machine guns for a heavier defensive "punch". For the light bomber role, up to 882lb of internal stores could be carried. A bomb bay separated the two cockpits and the ordnance was held vertically to save space.