Bristol Blenheim


Updated: January 2008

Developed for a private-venture design the aircraft was intended to the enter Royal Air Force Service as a light bomber. The design appeared just as the realization that the RAF needed to be re-equipped with more modern aircraft to replace their obsolete Hart and Hind biplane bombers.

In August 1935, 150 aircraft were ordered straight off of the drawing board. The first prototype (K7033) flying in June 1936 just one year after the initial order had been placed. The Blenheim Mk.I was soon out-performing all of the RAF's current fighters and development was rapid. By March 1937, No. 114 Squadron, RAF stationed at Wyton, became the first squadron to operate the new type.

A total of 1134 Blenheim Mk. I's were built and despite the severe limitations of the aircraft, which became clear as more modern fighter aircraft began to appear. The Blenheim Mk. I was to prove a vital link in bringing the RAF bomber forces to a position from where they could move forward into more advance aircraft.

By the outbreak of World War II the Mk. I's had in the mainly been replaced with the Mk. IV. This mark giving the crew a more comfortable seating arrangement and by the addition of a scalloped nose; the pilot gained improved visibility when landing and taxing the aircraft. The overall performance of the aircraft however, was not significantly improved from the earlier mark.

During the first two years of the war, Blenheim's had several modifications made to them, which included: extra armament and armour plate being added in an attempt to improve the survivability of the aircraft to fighter and flak damage. However, even with these modifications daylight operational losses still remained high. And with few options available to the Air Ministry; Blenheim equipped Squadron's were to shouldered the brunt of Bomber Command's daylight operations for the first two years of the war.


Blenheim IV Data


Crew: Three


Engines: Two 905 hp Bristol Mercury XV


Wing Span: 56'-6" (17.22m)


Length : 42'-7" (12.98m)


Height : 9'-10" (2.99m)


Empty Weight : 9,700 lbs. (4,400 kg)


Loaded Weight: 14,400 lbs. (6,532 kg)


Maximum Speed: 266 mph at 11,800 ft. (3,597 m)


Ceiling : 22,000 ft. (6,706 m)



One fixed 0.303" machine gun, dorsal turret and under-nose blister each with two 0.303" machine guns.


Maximum bomb load, 1,000 lbs. (4,536 kg) internally, plus 320 lbs. (145 kg) mounted externally.



Bomber Command Squadrons Equipped With The Blenheim IV


15, 18, 21, 34, 35, 40, 44, 57, 61, 62, 82, 88, 90, 101, 104, 105, 107, 108, 110, 114, 139, 144, 218, 226

Blenheim Mk. I

Blenheim Mk. IV