Overview
Just two of the developmental Bolkhovitinov high-speed bombers were built by the Soviet Union during World War 2.
Just two of the developmental Bolkhovitinov high-speed bombers were built by the Soviet Union during World War 2.
History
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.
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.
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.
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.
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.
Specifications
YEAR: 1940
MANUFACTURER(S): Bolkhovitinov - Soviet Union
PRODUCTION: 2
CREW: 1
LENGTH: 43.31 ft (13.2 m)
WIDTH: 45.28 ft (13.8 m)
HEIGHT: 9.84 ft (3 m)
EMPTY WEIGHT: 9,480 lb (4,300 kg)
MTOW: 12,467 lb (5,655 kg)
POWER: 2 x Klimov M-103 V12 liquid-cooled inline piston engine developing 960 horsepower each.
SPEED: 354 mph (570 kph; 308 kts)
RANGE: 435 miles (700 km; 378 nm)
OPERATORS: Soviet Union (cancelled)
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.
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.
Variants / Models
• 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.
• 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.
Our Data Modules allow for quick visual reference when comparing a single entry against contemporary designs. Areas covered include general ratings, speed assessments, and relative ranges based on distances between major cities.
Relative Maximum Speed
Hi: 400mph
Lo: 200mph
This entry's maximum listed speed (354mph).
Graph average of 300 miles-per-hour.
City-to-City Ranges
NYC
LDN
LDN
PAR
PAR
BER
BER
MSK
MSK
TKY
TKY
SYD
SYD
LAX
LAX
NYC
Graph showcases the Bolkhovitinov S (Sparka)'s operational range (on internal fuel) when compared to distances between major cities.
Aviation Era
Useful in showcasing the era cross-over of particular aircraft/aerospace designs.
Unit Production (2)
Comm. Market HI*: 44,000 units
Military Market HI**: 36,183 units
2
2
