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Bolkhovitinov S (Sparka)

Soviet Union (1940)

Detailing the development and operational history of the Bolkhovitinov S (Sparka) High-Speed, Two-Seat, Twin-Engine Bomber Prototype Aircraft.

 Entry last updated on 2/16/2017; Authored by Staff Writer; Content ©www.MilitaryFactory.com



  Bolkhovitinov S (Sparka)  
Picture of 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.

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.
Design work on the Sparka was begun in 1937 and this led to construction of the first prototype the following year. By 1939, the first flyable form was readied as the "S-1" but the example lacked the proposed armament, wheeled undercarriage (skids were fitted instead), and installed just one of the two intended powerplants. A first-flight was recorded on January 29th, 1940. S-1 was then followed by "S-2" and this included all of the proposed components the S-1 lacked. In testing, the pair performed adequately - handling was a strong point - but was not as fast as expected and proved tricky when attempting take-off and landing actions.

The design was evolved into the ultimately-abandoned Bolkhovitinov "I" - with twin M-107 engines and other slight changes - and the Bolkhovitinov "D", a heavy bomber form which never saw the light of day. Other proposed forms related to the Sparka project included a dedicated attacker (with downward-firing heavy machine guns) and a dedicated interceptor (with upward-firing 37mm automatic cannon).

As tested, the Sparka managed a maximum speed of 354 miles per hour and ranged out to 435 miles. Nothing more came out of the project beyond the two aforementioned prototypes.
Bolkhovitinov S (Sparka) Specifications
National Flag Graphic
Soviet Union
Year: 1940
Type: High-Speed, Two-Seat, Twin-Engine Bomber Prototype Aircraft
Manufacturer(s): Bolkhovitinov - Soviet Union
Production: 2
Supported Mission Types
Air-to-Air
Interception
Unmanned
Ground Attack
Close-Air Support
Training
Anti-Submarine
Anti-Ship
Airborne Early Warning
MEDEVAC
Electronic Warfare
Maritime/Navy
Aerial Tanker
Utility/Transport
Passenger Industry
VIP Travel
Business Travel
Search/Rescue
Recon/Scouting
Special Forces
X-Plane/Development
Structural
Crew: 1
Length: 43.31 ft (13.2 m)
Width: 45.28 ft (13.80 m)
Height: 9.84 ft (3.00 m)
Empty Weight: 9,480 lb (4,300 kg)
MTOW: 12,467 lb (5,655 kg)


Installed Power
2 x Klimov M-103 V12 liquid-cooled inline piston engine developing 960 horsepower each.

Standard Day Performance
Maximum Speed: 354 mph (570 kph; 308 kts)
Maximum Range: 435 mi (700 km; 378 nm)


Armament
PROPOSED:
1 x 7.62mm ShKAS machine gun on trainable mounting in rear cockpit position (EARLY).
2 x 12.7mm UBT machine guns on trainable mounting in rear cockpit position (LATE).

Up to 882lb of conventional drop ordnance (held vertically) in internal bomb bay.


Operators List
Soviet Union (cancelled)

Series Model Variants
• Bolkhovitinov S - Base Series Name
• Bolkhovitinov I - Dimensionally larger dive bomber / fighter form developed by A.M. Isayev.
• Bolkhovitinov D - Proposed twin tandem-engine heavy bomber form.


Supported Weapon Systems
Graphical image of an aircraft medium machine gun
Graphical image of an aircraft heavy machine gun
Graphical image of an aircraft conventional drop bomb munition