Science Fair Project Encyclopedia
Bristol Blenheim, England, 2001
|Role||Light bomber, fighter|
|First Flight||June 25, 1936|
|Entered Service||March 1937|
|Manufacturer||Bristol Aeroplane Company, Rootes Securities, Avro, Canadian Vickers|
|Length||42 ft 9 in||13 m|
|Wingspan||56 ft 4 in||17.17 m|
|Height||12 ft 10 in||3.91 m|
|Wing area||469 ft²||43.57 m²|
|Empty||9,790 lb||4,441 kg|
|Loaded||14,400 lb||6,531 kg|
|Engines||2 x Bristol Mercury XV|
|Power||2 x 920 hp||686 kW|
|Maximum speed||266 mph||428 km/h|
|Combat range||1,950 miles||3,138 km|
|Service ceiling||31,500 ft||9,600 m|
|Rate of climb||1,500 ft/min||457 m/min|
|Guns||1 x .303 in (7.7 mm) Vickers K machine gun in nose|
2 x .303 in (7.7 mm) Browning machine guns in chin turret
2 x .303 in (7.7 mm) Browning machine guns in dorsal turret
(fighter variants: 4 x fixed .303 in (7.7 mm) Browning machine guns under fuselage)
|Bombs||1,000 lb||454 kg|
The design had started as a civilian aircraft, a project of Lord Rothermere, owner of the Daily Mail. In order to promote British aviation, he asked the industry to deliver the fastest civilian aircraft in Europe, capable of carrying 6 passengers and 2 crew members. Bristol responded with the Type 142, and when it first flew as Britain First in 1934 it proved to be faster than any fighter the RAF had at the time.
Needless to say the Air Ministry was interested in such a plane for their own uses, and quickly sent out Specification B.28/35 for prototypes of a bomber version of the 142M (M for "military"). The main changes were to move the wing higher on the fuselage from its former low position, to allow room under the spar for a bomb-bay. The aircraft was all-metal with twin Bristol Mercury radial engines of 860 hp (640 kW) each. It carried a crew of three – pilot, navigator/bombardier and gunner/wireless operator – and was armed with a forward firing 0.303-in machine-gun in the wing root and a 0.303-in (7.7-mm) machine-gun in a semi-retracting dorsal turret firing to the rear. A 1,000-lb (450-kg) bombload was carried in the internal bay.
The plane was ordered directly from the plans, and the first production model, known at the time as the Bolingbroke, served as the first and only prototype. The name then became Blenheim I, and deliveries started in 1937. The plane would prove to be so successful that it was licensed by a number of countries, including Finland and Yugoslavia. Other countries bought it outright, including Romania, Greece, and Turkey. Total production of the Blenheim in England amounted to 1,351 Mk.I's.
After France fell to Germany in June 1940, the Free French air force was formed at RAF Odiham in the guise of Groupe Mixte de Combat (GMC) 1, consisting of a mixed bag of Blenheims and Westland Lysander liaison/observation aircraft, which eventually went to North Africa and saw action against the Italians and Germans.
Work on an extended range reconnaissance version started as the Mk.II, which increased tankage from 278 to 468 gallons, but only one was completed. Another modification resulted in the Mk.III, which lengthened the nose to provide more room for the bombardier. This required the nose to be "scooped out" in front of the pilot to maintain visibility during takeoff and landing. However both of these modifications were instead combined, along with a newer version of the Mercury engine with 905 hp (675 kW) and a second gun in the rear cockpit, to create the Blenheim IV. When it was introduced in 1939, the Mk.IV (Type 149 to Bristol) was the fastest bomber in the world, and 3,307 would eventually be produced.
The longer range also lent itself to a Canadian need for a patrol bomber, and Fairchild started production there with the original name as the Bolingbroke. After a small run of British-like planes as the Mk.I, Fairchild switched production to the Mk.IV with American instruments and equipment. These versions also included anti-icing boots and a dinghy. Some of these planes served as bombers during the Aleutians campaign, but most of the 150 served in the intended role as patrol bombers on the Atlantic coast. Another 450 were completed as the Mk.IV-T as trainers, and saw extensive use in the Commonwealth Air Training Plan.
Another modification was attempted to create a heavy-fighter version, using a solid nose containing four more Browning machine-guns. Originally known as the Bisley, the production aircraft were renamed Blenheim V and featured a strengthened structure, pilot armour, interchangeable nose gun pack or bombardier position, and yet another new Mercury with 950 hp (710 kW). The Mk.V (Type 160) was used primarily in the Far East.
Blenheims operated widely in many combat roles until about 1943. By that point most fighters could carry similar bombloads at much higher speeds, and the surviving examples were relegated to training duty. Bristol's intended successor to the Blenheim, the Buckingham, was considered inferior to the Mosquito, and did not see combat.
Units using the Blenheim
|Royal Air Force squadrons|
6 8 11 13 14 15 18 21 23 25 27 29 30 34 35 39 40 42 44 45 52 53 55 57 59 60 61 62 64 68 82 84 86 88 90 92 101 104 105 107 108 110 113 114 139 140 141 143 144 145 162 173 203 211 212 218 219 222 223 226 229 233 234 235 236 242 244 245 248 252 254 267 272 285 287 288 289 404 406 407 454 459 489 500 516 521 526 527 528 600 601 604 608 614
|Fleet Air Arm squadrons|
748 759 762 770 771 772 775 776 780 787 788 798
404 406 407 415 419
|Similar aircraft||De Havilland Mosquito|
|Designation series||Type 130 - Type 142 - Type 152|
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