Bristol Blenheim, RIAT 2015 ©Nigel Key
ROLE
Light Bomber / Heavy Fighter / Reconnaissance.
FIRST FLIGHT
12 April 1935.
The Blenheim was an all-metal aircraft designed by Frank Barnwell which was powered by two Bristol Mercury VIII air-cooled radial engines, each producing 860 hp. The crew consisted of three, a pilot, navigator/bombardier and telegraphist/air gunner.
The Mk I Blenheim had a small cross-section fuselage with the upper front glazed for the pilot with no need for separate windscreen panels.
The bomb bay doors were kept closed by 'bungee cords' and opened by the weight of the bombs when released. The time taken for the bombs to 'force' open the bomb doors was unpredictable resulting in poor bombing accuracy.
An extended range development version of the Blenheim, denoted Mk II, had increased fuel tank capacity from 278 gallons to 468 gallons, with only one aircraft being produced.
A further development aircraft denoted as Mk III had a lengthened nose, with a true windscreen for the pilot, to provide more room for the bomb aimer.
The modifications from both the Mk II and Mk III development aircraft, together with new more powerful engines were fitted to the Blenheim and designated Mk IV.
A further modification to produce a long-range fighter was made to incorporate guns under the fuselage for four 0.303" Browning machine guns and designated Blenheim Mk IF.
The last bomber variant was an armoured ground-attack aircraft with four extra Browning 0.303" machine guns in the nose and was designated as a Blenheim Mk V.
PRODUCTION
The Bristol Blenheim was produced from 1937, with over 4,400 built.
ENGINES
2 x Bristol Mercury XV’s, producing 1,810 hp.
ARMAMENT
2 x Browning 0.303” machine guns
1,320 lb (600 kg) Bomb load
The first squadron to receive the Blenheim was No.114 Squadron in early 1937 and by the outbreak of WWII a total of 168 Blenheim Mk IV was operational with the RAF.
A Blenheim was the first British aircraft to cross the German coast on a reconnaissance mission on the day war broke out on 3 September 1939.
Due to rapid advances in technology, in January 1941, the Air Staff classified the Blenheim as inadequate in terms of performance and armament for current operations.
| Crew - 3 |
| Length - 42ft 7in (12.98m) |
| Wingspan - 56ft 4in (17.17m) |
| Height - 9ft 10in (3m) |
| Empty Weight - 9,790lb (4,441kg) |
| Max. Weight - 14,400lb (6,532kg) |
| Max. Speed - 266 mph (428 km/h) |
| Range - 1,460 miles (2,350 km) |
