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103-428: The HAF Underwater Operations Team (KOSYTHE) helped recover some rare aircraft from underwater for the museum: a Bristol Blenheim , a Junkers Ju 52/3m and a Junkers Ju 87 . 38°06′17.7″N 23°46′42.4″E  /  38.104917°N 23.778444°E  / 38.104917; 23.778444 This aerospace museum–related article is a stub . You can help Misplaced Pages by expanding it . This article related to

206-481: A Staffelkapitän identified as Hauptmann Albrecht von Ankum-Frank. Two other 109s were claimed by Blenheim gunners. Another successful raid on Haamstede was made by a single Blenheim on 7 August which destroyed one 109 of 4./JG 54, heavily damaged another, and caused lighter damage to four more. There were also some missions which produced an almost 100% casualty rate amongst the Blenheims. One such operation

309-562: A light bomber and aerial reconnaissance aircraft. As soon as more capable purpose-built designs became available, it was relegated to use as a liaison and courier aircraft . During the late 1930s, 28 aircraft were sent to Spain as part of the German-manned Legion Condor . These aircraft saw action during the Spanish Civil War , typically as fast reconnaissance aircraft. There they were known as

412-632: A Blenheim from the Fighter Interception Unit (FIU) at RAF Ford achieved the first success on the night of 2–3 July 1940, accounting for a Dornier Do 17 bomber. The Blenheim was replaced by the faster and more heavily-armed Bristol Beaufighter in 1940–1941. On 11 June 1940, only hours after Italy's entry into the war on Germany's side, several Blenheim IVs bombed Italian positions. In mid-1940, reinforcement ferry routes were established throughout Africa, starting in Takoradi on

515-406: A few key locations, such as near to the main wing fittings. The fuselage, wings, and control surfaces were all shell-plated and flush riveted to create a relatively smooth surface to minimize drag and help fulfil the aircraft's demanding speed requirements. For similar reasons, all fittings, including the foot steps and door knobs, were inset and flush windows fitted. Another drag-reduction measure

618-745: A few months. The Mk IF proved to be slower and less manoeuvrable than expected, and by June 1940 daylight Blenheim losses caused concern for Fighter Command. The Mk IF was relegated mainly to night fighter duties where No. 23 Squadron RAF , which had already operated them at night, soon relegated them to night intruder operations as they were not effective as night fighters. In the German night-bombing raid on London on 18 June 1940, Blenheims accounted for five German bombers, thus proving that they were better-suited for night fighting. In July, No. 600 Squadron, by then based at RAF Manston , had some of its Mk IFs equipped with AI Mk III radar. With this radar equipment,

721-490: A guaranteed top speed of 312 kmph while maintaining identical cabin dimensions, wing loading, and landing speeds to its American-built competitors. The aircraft's speed was prioritised over all other potential improvements. A low-wing cantilever monoplane configuration was selected in order to achieve low drag along with a permissible fuselage cross-section for the desired cabin space, which needed to accommodate two pilots, five passengers, and their baggage. The arrangement

824-597: A huge variety of spare parts, although some of these had been damaged or otherwise destroyed through sabotage . Yugoslavia had ceased production of the Mk I and commenced a production run of Mk IVs just prior to the April 1941 invasion. The British-made Blenheims had RAF green interiors, RAF seat belts and instruments on imperial units, while Finnish-made Blenheims had medium grey interiors, Finnish-style seat belts and metric instruments. The Finnish Blenheims flew 423 missions during

927-478: A manner that ensured sufficient lateral stability. Wing flaps were initially not used in order to save weight, increase simplicity, and pursue greater top speeds; while the aircraft maintained satisfactory landing characteristics during testing, it was decided to add compact flaps so that shorter landing strips could be used by the He 70. Various configurations were trialled. Various wing configurations were considered,

1030-411: A metal frame covered with fabric. The undercarriage was hydraulically -retracted, with an auxiliary hand-pump for emergency actuation; medium-pressure tyres were used, complete with pneumatically -actuated differentially-control brakes. The Blenheim typically carried a crew of three – pilot, navigator/bombardier and wireless (radio) operator /air gunner. The pilot's quarters on the left side of

1133-697: A museum in Greece is a stub . You can help Misplaced Pages by expanding it . This article about a building or structure in Athens is a stub . You can help Misplaced Pages by expanding it . Bristol Blenheim The Bristol Blenheim is a British light bomber designed and built by the Bristol Aeroplane Company , which was used extensively in the first two years of the Second World War , with examples still being used as trainers until

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1236-427: A relatively compact retractable radiator as a further drag-reducing measure. The first prototype performed its maiden flight on 1 December 1932 and set eight separate world speed records over the following months. The He 70 was adopted by Deutsche Lufthansa in 1934, although its commercial career was relatively brief before the type was eclipsed by larger and more capable aircraft. In addition to its civilian use,

1339-659: A replica of the Electra". It was designated Type 135 . In early 1934, Lord Rothermere , owner of the Daily Mail newspaper, challenged the British aviation industry to build a high-speed aircraft capable of carrying six passengers and two crew members – he referred to the ambition as seeking "the fastest commercial aeroplane in Europe, if not the world". German firms were producing record-breaking high-speed designs, such as

1442-484: A semi-retracting Bristol Type B Mk I dorsal turret firing to the rear. From 1939 onwards, the Lewis gun was replaced by the more modern .303 in (7.7 mm) Vickers VGO machine gun . A 1,000 lb (450 kg) bomb load could be carried in the internal bomb bay set into the centre section of the fuselage. Like most contemporary British aircraft, the bomb bay doors were kept closed with bungee cords and opened under

1545-581: A wider and rapid expansion of the RAF. The first aircraft built of this production model, K7033 , served as the only prototype; on 25 June 1936, K7033 conducted its first flight from Filton. The service name for the aircraft became Blenheim Mk I after the famous battle during the War of the Spanish Succession . On 10 March 1937, production deliveries to the RAF formally started; 114 Squadron became

1648-699: A wing shape from an aircraft designed for an entirely different purpose. The Günther brothers had already used an elliptical wing for the Bäumer Sausewind sports aircraft before they joined Heinkel. Shenstone said that the He 70's influence on the Spitfire design was limited to use as a benchmark for aerodynamic smoothness. Data from The Beautiful Blitz General characteristics Performance Armament Related development Aircraft of comparable role, configuration, and era Related lists Note: Official RLM designations had

1751-424: Is a baggage hold. It was powered by a single BMW VI V-12 engine , capable of producing up to 470 kW (630 hp) at 1,600 rpm. Unusually, this engine was cooled using ethylene glycol rather than water, which enabled the use of a more compact radiator . This radiator, which was located beneath the fuselage, had one-third of the frontal surface area of a conventional counterpart and could be retracted when

1854-448: Is also built in three sections, the centre-section of which is bolted and rivetted to the fuselage. The outer wing sections are tapered in chord and thickness. Extensive use of Alclad sheeting is made in elements such as the ribs , skin, flaps , and web reinforcement of the spars . The tail unit is of a cantilever monoplane style, using an all-metal tailplane and fin while the aerodynamically-balanced rudder and elevators use

1957-677: The British Expeditionary Force of the Army . In May 1940, AASF and BEF Blenheims participated in the Battle of France , being sent against German forces moving towards Brussels , resulting in many aircraft quickly sustaining heavy damage or being lost to enemy fire. German attacks upon the French airfields also damaged a considerable number of Blenheims on the ground. On 14 May, a combined force of Fairey Battles and Blenheims

2060-538: The DFC for his part in the raid. From 5 September 1940 Blenheims of Bomber Command began a bombing campaign targeting German-occupied ports along the English Channel , alongside heavier bomber types. Bomber Command Blenheims also performed anti-shipping patrols due to Coastal Command's own strike squadrons being heavily depleted throughout the latter half of 1940. On 11 March 1940, a Blenheim IV, P4852 , became

2163-555: The Dunkirk evacuation by harassing enemy forces. Rapid advances in technology which had taken place in the late 1930s had rendered the Blenheim mostly obsolete by the outbreak of the war. In particular, it had become heavier as extra service equipment was installed; much of this was found to be necessary through operational experience. This, coupled with the rapid performance increases of the fighters that would oppose it, had eclipsed

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2266-659: The Gold Coast . By the end of 1940, a total of three RAF squadrons equipped with Blenheim IV aircraft were performing anti-shipping, bombing, and reconnaissance missions in support of Allied ground forces in North Africa. By July 1941, it had been recognised that, in response to the increasing intensity of combat in North Africa and in the Middle East theatres, additional squadrons were urgently required. In

2369-561: The Heinkel He 111 , a larger bomber that featured similar elliptical wings and a streamlined fuselage . The Heinkel He 70 Blitz (Lightning) was designed in the early 1930s as a mailplane for Deutsche Lufthansa in response to a request for an aircraft faster than the Lockheed Model 9 Orion (used by Swissair ) to service short routes. While German officials initially specified a desired top speed of 250 kmph in 1931, this

2472-610: The Imperial Japanese main carrier battle group . The Blenheims approached undetected by the A6M2 Zero combat air patrol (CAP) fighters, resulting in a total surprise-attack upon the Japanese carrier battle group. While the bombers were able to drop bombs on fleet carrier Akagi from an altitude of 11,000 feet (3,353 m), they fell off-target without scoring any hits. Four of the Blenheims were shot down over

2575-710: The RAF Advanced Air Striking Force (AASF) was deployed to numerous airfields in France, allowing for shorter range bombing missions against German targets, including industries. Several squadrons of Blenheim IVs were assigned to the AASF, being frequently used against targets in France and the Low Countries once the Battle of France had begun. Blenheims were also assigned to the air component of

2678-690: The Rayo , Spanish for "lightning". A single example was bought by Rolls-Royce for use as an engine testbed: it continued in use until 1944. The He 70K (later given the RLM number: He 170) was a fast reconnaissance airplane export variant used by the Hungarian Air Force. Powered by a Gnome-Rhône Mistral Major radial engine , the engines were built under license in Hungary as the WM-K-14 , but

2781-590: The fall of France in June 1940, the Free French Air Force was formed at RAF Odiham , Hampshire , in the form of Groupe Mixte de Combat (GMC) 1, consisting of a mixed bag of Blenheims and Westland Lysander liaison/observation aircraft, which were later dispatched to North Africa and saw action against Italian and German forces. Blenheim units operated throughout the Battle of Britain , often taking heavy casualties, although they were never accorded

2884-442: The main spar to accommodate a sizeable bomb bay. Other modifications included the addition of a bomb-aimer's position and a Browning machine gun in the port wing along with provisions for a semi-retractable gun turret in the dorsal position. In September 1935, an initial contract for 150 aircraft was placed. The Air Ministry had chosen to order the type directly from the drawing board, having been urgently sought as one piece of

2987-414: The rudder was controlled using a pedal. A third seat, intended for use by a mechanic or a single passenger, was also present in the cockpit. Aft of the flight crew's position was a compact cabin that seated up to four passengers in pairs facing each other. The passenger cabin was provisioned with air-based heating and ventilation and large windows that could be used as emergency exits. Aft of this cabin

3090-664: The Blenheim IV continued until June 1943, when newcomers such as the Beaufort -derived Beaufighter had succeeded the type. A total of 3,307 were produced. A long-range fighter version, the Blenheim Mk IF, was also developed. For this role, about 200 Blenheims were fitted with a gun pack under the fuselage for four .303 in (7.7 mm) Brownings. Later, the Airborne Intercept (AI) Mk III or IV radar

3193-532: The Blenheim Mk II, which increased tankage from 278 to 468 imp gal (1,260 to 2,130 L; 334 to 562 US gal). Only one Blenheim Mk II was completed, as flight tests revealed the increase in speed to be marginal and not warranting further development. Another modification resulted in the Blenheim Mk III, which lengthened the nose, dispensing with the "stepless cockpit" format of

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3296-589: The Blenheim Mk IV. In early 1939, the first batch of Blenheim Mk IVs were accepted into service; these lacked outer fuel tanks but were accepted due to the urgent demand for the type. Early Blenheim Mk IVs were also equipped with the Mercury VIII engine, most were fitted with the more powerful Mercury XV or Mercury 25 models. Further aircraft deliveries were made to the production standard and were primarily manufactured by Avro and Rootes. Production of

3399-472: The Blenheim Mk.I had been subject to considerable criticism, prompting the development of an improved model to rectify the shortcomings. On 24 September 1937, an experimental Blenheim Mk.I, modified with an extended forward fuselage beyond its original stepless cockpit , smooth-fronted nose enclosure, made its first flight from Filton. Formal work on an extended-range reconnaissance version started as

3502-576: The Blenheim's speed advantage. In January 1941, the Air Staff classified the Blenheim as inadequate in terms of performance and armament for current operations. The light armament was seldom able to deter fighter opposition. Squadrons were forced to use several different improvisations in an attempt to provide better defensive armament, until officially sanctioned modifications were able to be introduced in early 1940. The Blenheim also proved to be vulnerable to anti-aircraft artillery , especially around

3605-557: The Blenheim, including Romania , Greece and Turkey . By September 1939, orders for the Blenheim had risen to 2,088 aircraft. Total production of the Blenheim Mk I in England was 1,351 aircraft prior to the end of the production run in 1939; production had been terminated in favour of more advanced variants. The Blenheim production programme saw several shifts in requirements and in capacity. A modified Blenheim design, given

3708-712: The Blenheim, ordering 18 Blenheim Mk Is, which were delivered from Britain between June 1937 and July 1938. Two years later, Finland obtained a manufacturing licence for the Blenheim. Before any aircraft could be manufactured at the Valtion lentokonetehdas (State Aeroplane Factory) in Finland, the Winter War broke out, forcing the Finns to order more aircraft from the UK. A further 24 British-manufactured Blenheims were ordered during

3811-407: The Blenheims once again proved to be too slow and vulnerable against Luftwaffe fighters and they took constant casualties. On 12 August 1941, an action described by The Daily Telegraph in 2006 as being the "RAF's most audacious and dangerous low-level bombing raid, a large-scale attack against power stations near Cologne" took place. The raid was a low-level daylight raid by 54 Blenheims under

3914-436: The He 70 commenced in the early 1930s in response to a request from Deutsche Lufthansa for a fast mail plane . Heinkel designed a low-wing cantilever monoplane that incorporated various measures to minimise drag , including its use of an aerodynamically efficient elliptical wing , a smooth external finish, and a retractable undercarriage . The He 70 was powered by a single nose-mounted BMW VI 7.3 Z engine and cooled via

4017-632: The He 70 was also adapted for military purposes, in which capacity it was flown in both the bomber and aerial reconnaissance capacities. In addition to the Luftwaffe, militarised models were operated by both the Royal Hungarian Air Force and the Ejército del Aire . The type was already relegated to secondary roles, such as training, by the outbreak of the Second World War . The He 70 is perhaps best known as being an ancestor to

4120-638: The Middle East and Far East – received this variant but operated them generally only for a few months. One Blenheim Mk IV left in Java by the retreating British forces in 1942 ended up in the hands of the fledgling Indonesian Air Force (AURI). They repaired it, installed 950 hp (699 kW) Nakajima Sakae engines, painted it in their colours, and flew it around Yogyakarta on at least three occasions. On 9 April 1942, nine Blenheims from 11 Squadron RAF attacked Admiral Chuichi Nagumo's Kidō Butai ;

4223-647: The Middle East were relocated from the theatre to the Far East in response to the new threat from Japanese forces. Blenheims continued to operate widely in many combat roles until about 1943, equipping RAF squadrons in the UK and at British bases in Aden , India, British Malaya , Singapore, and the Dutch East Indies . Many Blenheims were lost to Japanese fighters during the Malayan Campaign and

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4326-485: The Mk.I, introducing a true windscreen in front of the pilot, to provide more room for the bomb aimer. This required the nose to be "scooped out" in front of the pilot to maintain visibility during takeoff and landing. Both modifications were combined, along with a newer version of the Mercury engine with 905 hp (675 kW). The turret acquired a pair of Brownings in place of the original single Vickers K gun, creating

4429-469: The RAF's biplane fighters in the late 1930s but advances soon left it vulnerable if flown in daylight, though it proved successful as a night fighter. The Blenheim was effective as a bomber but many were shot down. Both Blenheim types were used by foreign operators and examples were licence built in Yugoslavia and Finland, in addition to Canada. In 1933 Frank Barnwell , Bristol's chief designer, went to

4532-487: The Spitfire wing was copied from the He 70. Shenstone said: It has been suggested that we at Supermarine had cribbed the wing shape from that of the He 70 transport. This was not so. The elliptical wing had been used on other aircraft and its advantages were well known. Our wing was much thinner than that of the Heinkel and had a quite different section. In any case, it would have been simply asking for trouble to have copied

4635-631: The Type 142M became the Blenheim Mk.I which would be developed into the long-nosed Type 149, the Blenheim Mk.IV, except in Canada where Fairchild Canada built the Type 149 under licence as the Bolingbroke. The Type 160 Bisley was also developed from the Blenheim but was already obsolete when it entered service. Both versions were converted into heavy fighters by the addition of a gun pack with four Browning .303 in (7.7 mm) machine guns mounted under

4738-558: The United States to collect first-hand information on their latest twin-engined, low-wing monoplane airliners. When he returned home he discussed one of them, the Lockheed Electra 12A , with Roy Fedden and prepared a design to match it using Fedden's Bristol Aquila engine which produced 500 hp, the same power as the engine used in the Electra. Sir Archibald Russell described Barnwell's design as "close to being

4841-617: The Winter War and were delivered from the RAF's own stocks. In the aftermath of the Winter War, 55 Blenheims were constructed in Finland, the final aircraft being completed in September 1944; this brought the total number of Blenheims in Finnish service to 97 (75 Mk Is and 22 Mk IVs). The Finns also received 20 half-completed ex-Yugoslavian Mk IV Blenheims captured by Germany, together with manufacturing tools, production equipment, and

4944-657: The Winter War, and close to 3,000 missions during the Continuation War and Lapland War . Blenheim machine-gunners also shot down eight Soviet aircraft. Thirty-seven Blenheims were lost in combat during the wars. The Finnish Blenheims were divided on six series ( sarja ): Series I with doorless bomb bays could carry 1,800 lb (800 kg) bomb load in the bomb bay and up to 220 lb (100 kg) in wing cells. Series II, V and VI could carry 1,800 lb (800 kg) load on bomb bay and 379 lb (172 kg) on wing cells and fuselage racks. Series III and IV had

5047-546: The aircraft was faster than the fighters in service with the Royal Air Force (RAF), having a top speed of 307 mph (494 km/h). Rothermere presented the aircraft to the nation for a formal evaluation as a potential bomber. By June 1935, the Air Ministry had become interested in the project due to its high performance. On 9 July 1935, a design conference was held by Bristol at the ministry's request into

5150-417: The aircraft was flying at high speeds to further reduce drag. The bottom of the oil tank, which was partitioned, was used for cooling; a wing pump was used for oil circulation. Both the engines and their cowlings were streamlined wherever practical to do so. the aircraft was considered to be capable of achieving even higher speeds if it were to be outfitted with more powerful engines. On 1 December 1932,

5253-422: The aircraft's completion however. It was typically flown by a crew of two, a pilot and radio operator, who were seated in a tandem configuration in a fairly central position within the fuselage that was slightly elevated for better visibility. Visibility was further bolstered by the presence of a transparent movable cabin roof and an adjustable seat. The elevators and ailerons were actuated using wheels while

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5356-467: The airframe manufacture and final assembly took place in Germany. The new engines raised the top speed of the aircraft from 360 to 435 km/h (224 to 270 mph). 18 were used by the Royal Hungarian Air Force from 1937 to 1942. A major weakness of the He 70 in military use was the fire risk. Parts of the airframe were made out of an extremely flammable magnesium alloy called " elektron ", though

5459-533: The airframe would have to possess favourable aerodynamic performance as well. On 12 February 1932, a formal order was placed for the design and construction of an aircraft designated He 65 , which had a guaranteed top speed of 285 kmph. However, in July of that year, it was decided to modify the design so that it could achieve a greater maximum speed; this redesign received the He 70 designation. The redesigned aircraft had

5562-412: The antecedent for some of the bombers involved in the Battle of Britain . The He 70 is known mainly as the ancestor to the Heinkel He 111 , which had similar elliptical wings and streamlined fuselage in a twin-engined configuration. The He 111, which began service with the Luftwaffe in 1936, went on to become the most numerous bomber type of the Luftwaffe – with just over 5,600 examples produced during

5665-620: The basis for the Beaufort torpedo bomber , which led to the Beaufighter, with the lineage performing two evolutions of bomber-to-fighter. The Bristol Blenheim was a twin-engine high performance all-metal medium bomber aircraft, powered by a pair of Bristol Mercury VIII air-cooled radial engines , each capable of 860 hp (640 kW). Each engine drove a three-bladed controllable-pitch propeller , and were equipped with both hand-based and electric engine starters. To ease maintenance,

5768-449: The basis for, a bomber aircraft. Rothermere became aware of Bristol's Type 135 proposal and on 3 March 1934, Barnwell issued him with a quote of the specification and performance statistics of the design, including an estimated top speed of 240 mph (390 km/h) at 6,500 ft (2,000 m). The Aquila engine had been shelved in favour of the supercharger -equipped, poppet-valve Bristol Mercury engine. Deeming it suitable for

5871-399: The battles for Singapore and Sumatra . By that point, the traditional daylight light bomber role was more effectively carried out by suitable fighter-bombers, and the surviving examples were relegated to training duties. Nonetheless, the Blenheim played a role in preventing India from falling and in recapturing Burma , destroying over 60 aircraft on the ground in raids on Bangkok early in

5974-436: The cabin were riveted to the skin. The bulkheads themselves were not directly connected to the skin. The fuselage terminated in a series of longitudinal channels that rested on circular bulkheads and was riveted to the skin. While not particularly resistant to buckling , the amount that did occur even under high stresses was considered to be reasonably minor. Thick shell plates for conveying local stresses were only present in

6077-530: The cabin, all of which led to the Hungarian He 170A fleet being prematurely retired and replaced with obsolescent Heinkel He 46 parasol-wing monoplanes, until Focke-Wulf Fw 189 "Uhu" medium altitude observation aircraft could be introduced. While the He 70 saw only limited service in training capacities during the Second World War, it was the Luftwaffe's first Schnellbomber and served as

6180-512: The campaign. One Blenheim pilot, Squadron Leader Arthur Scarf , was posthumously awarded the Victoria Cross for an attack on Singora , Thailand , on 9 December 1941. Another bomber of No. 60 Squadron RAF was credited with shooting down Lt Col Tateo Katō 's Nakajima Ki-43 fighter and badly damaging two others in a single engagement on 22 May 1942, over the Bay of Bengal . Katō's death

6283-412: The carriers by CAP Zeroes (two of which were claimed by ace-fighter pilot Kaname Harada from the Soryu ), and by other Japanese aircraft returning from the earlier-strike on HMS Hermes , shooting down two Zeroes in return. This was the first time a Japanese carrier force had faced a concerted air attack in the Pacific War . In 1936, the Finnish Air Force became the first export customer for

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6386-523: The challenge, the design of Type 135 was further adapted to produce the Type 142 to meet the requirements outlined by Rothermere. In late March 1934, Rothermere placed an order for a Type 142 aircraft, under which he paid for half of the estimated £18,500 cost up front and the remainder upon the aircraft's first flight in the following year. On 12 April 1935, the Type 142 , named Britain First , conducted its maiden flight from Filton Aerodrome , South Gloucestershire . Flight tests soon proved that

6489-400: The command of Wing Commander Nichol of No. 114 Squadron RAF . They hit their targets (Fortuna Power Station in Oberaußem-Fortuna and the Goldenberg Power Station in Hürth-Knapsack ), but twelve of the Blenheims were lost during the raid, 22% of those that took part, which was far above the sustainable loss rate of less than 5%. The England cricketer Squadron leader Bill Edrich was awarded

6592-408: The day that war was declared on Germany, a Blenheim Mk IV, N6215 , piloted by Flying Officer Andrew McPherson was the first British aircraft to cross the German coast to perform a high altitude reconnaissance mission upon the German Navy in the vicinity of Wilhelmshaven , Lower Saxony . The following morning, 15 Blenheims from three squadrons set off on one of the first bombing missions to attack

6695-400: The demand, secondary assembly lines were established at Chadderton by Avro and at Speke by Rootes Securities . The aircraft was built under licence by foreign countries, including Finland , who completed a total of 55 aircraft, and Yugoslavia , which completed 16 aircraft with a further 24 in advanced stages of completion when Germany invaded Yugoslavia . Other countries also procured

6798-446: The design team having to balance pure aerodynamic performance against various other factors and characteristics, such as roll damping , weight, and the need to accommodate the retractable undercarriage. Particular care was paid to obtain a high level of torsional stiffness and a sufficient margin against any oscillations, which was a particular problem for cantilever wings. The selected wing's profile thickness tapered considerably towards

6901-440: The end of the war. Development began with the Type 142 , a civil airliner, after a challenge from the newspaper proprietor Lord Rothermere to produce the fastest commercial aircraft in Europe. The Type 142 first flew in April 1935, and the Air Ministry , ordered a modified design as the Type 142M for the Royal Air Force (RAF) as a bomber. Deliveries of the new Blenheim to RAF squadrons commenced on 10 March 1937. In service

7004-401: The engine mountings were designed with a split-segment to facilitate rapid engine removal without disturbing the carburettors . A pair of fuel tanks, each containing up to 140 gallons, were housed within the centre-section of the fuselage. The fuselage of the Blenheim employed a light- alloy monocoque structure using open-section stringers , and was constructed in three sections. The wing

7107-448: The first RAF aircraft to sink a U-boat , having scored two direct hits on U-31 in the Schillig Roads . In April 1941, a campaign aiming to completely close off the Channel to enemy shipping was launched using an initial flight of Blenheims stationed at RAF Manston . Between April and June that year, a total of 297 Blenheims of No 2. Group attacked German shipping at sea, losing 36 aircraft, while Coastal Command launched 143 attacks in

7210-427: The first prototype performed its maiden flight . Flight testing proved it to possess excellent performance, setting eight world records for speed over distance, and reaching a maximum speed of 377 km/h (234 mph). Luft Hansa operated He 70s between 1934 and 1937 for a fast service which connected Berlin with Frankfurt , Hamburg and Cologne , as well as between Cologne and Hamburg. Between 1934 and 1936,

7313-428: The first squadron to receive the Blenheim. On 13 January 1938, the Blenheim entered service with No. 30 Squadron , the first overseas squadron to receive the type; in early 1939, the first Blenheims arrived in India. From July 1936 onwards, various additional orders were placed for the Blenheim Mk I , including multiple orders for the export market. By the end of 1936, 1,568 aircraft were on order. In order to meet

7416-470: The form of a "stepless cockpit" that used no separate windscreen panels for the pilot, a notable feature of a substantial majority of German bomber designs, first conceived during the war years. Both fixed and sliding window panels were present, along with a transparent sliding roof. Other onboard equipment included a radio , cameras , navigation systems, electric lighting , oxygen apparatus, and stowage for parachutes and clothing. In September 1939,

7519-409: The fuselage. The Mk.IV was also used as a maritime patrol aircraft and both aircraft were also used as bombing and gunnery trainers once they had become obsolete as combat aircraft. The Blenheim was one of the first British aircraft with an all-metal stressed-skin construction, retractable landing gear , flaps , a powered gun turret and variable-pitch propellers . The Mk.I was faster than most of

7622-596: The last flight of a Finnish Blenheim taking place on 20 May 1958. The usual nickname of Blenheim in the Finnish Air Force was Pelti-Heikki ("Tin Henry"). In Finland, the sole surviving original Blenheim in the world, a Mk IV registered as BL-200 of the Finnish Air Force, has been completely restored and is now on display at the Aviation Museum of Central Finland at Tikkakoski. An airworthy Blenheim

7725-662: The latter half of 1941, several Blenheim squadrons were flown out to Malta , many being stationed there into early 1942 before mainly being absorbed in the Western Desert air operations. As Bomber Command gradually took Blenheims out of the Northern Europe theatre, they were often dispatched to other areas such as North Africa. Upon the outbreak of the Pacific War in December 1941, some Blenheim squadrons in

7828-406: The majority of the monocoque fuselage was duralumin . Elektron is very light yet strong, but burns readily when ignited and is difficult to extinguish. Moreover, each wing contained a non-self-sealing 210-litre (47-imperial-gallon) fuel tank, which may have further added to the aircraft's reputation for catching fire. Other problems included poor defensive armament, short range and poor view from

7931-406: The month in which the Second World War broke out, the Blenheim Mk I equipped two home-based squadrons and 11 overseas squadrons in locations such as Egypt , Aden , Iraq , India , and Singapore . Further RAF squadrons had received, or were in the process of converting to, the more capable Blenheim Mk IV; 168 Blenheim Mk IV aircraft had entered RAF operational strength by the outbreak of war. On

8034-535: The more capable Beaufighter derivative. About 60 Mk IVs were also equipped with the gun pack as the Mk IVF and were used by Coastal Command to protect convoys from German long-range bombers. The last bomber variant was conceived as an armoured ground attack aircraft , with a solid nose containing four more Browning machine guns. Originally known as the Bisley, (after the shooting competitions held at Bisley Ranges ),

8137-483: The name Bolingbroke , was manufactured under licence in Canada by Fairchild Aircraft . The Bolingbroke, which had been developed in response to Air Ministry Specification G.24/35 to procure a coastal reconnaissance/light bomber as a replacement for the Avro Anson , had substantial improvements that would serve as the basis for improved variants of the Blenheim. Both the navigator's station and range limitations of

8240-611: The northern areas of the British mainland, such as RAF Lossiemouth , flying for extended periods over the North Sea led to the weather posing almost as much of a risk as enemy combatants, particularly as most of the Blenheim IVs lacked any heating or deicing systems; in response, some aircraft were later equipped with boilers fixed onto the starboard engine exhaust. A sizeable number of losses occurred, caused by both enemy action and mid-air engine failures due to icing . After

8343-406: The nose were so cramped that the control yoke obscured all flight instruments while engine instruments eliminated the forward view on landings. Most secondary instruments were arranged along the left side of the cockpit, essential items such as the propeller pitch control were actually placed behind the pilot where they had to be operated by feel alone. The navigator/bombardier was seated alongside

8446-573: The original RAF bomb bays and racks and could carry only 1,000 lb (450 kg) load on bomb bay and 200 lb (91 kg) on wing cells. The bomb bays, bomb bay doors and bomb racks of various series were modified on major overhauls to host bigger bombs. After the war, Finland was prohibited from flying bomber aircraft by the Paris Peace Treaty , with Finland's Blenheims being placed into storage in 1948. However, in 1951, five Blenheims were re-activated for use as target tugs , with

8549-409: The pilot, and made use of a sliding/folding seat whilst performing the bomb aiming role. Dual flight controls could be installed. The wireless operator/air gunner was housed aft of the wing alongside the aircraft's dorsal gun turret. Armament comprised a single forward-firing .303 in (7.7 mm) Browning machine gun outboard of the port engine and a .303 in (7.7 mm) Lewis Gun in

8652-433: The production aircraft were renamed Blenheim Mk V and featured a strengthened structure, pilot armour, interchangeable nose gun pack or bomb-aimer position and another Mercury variant with 950 hp (710 kW). The Mk V was ordered for conventional bombing operations, with the removal of armour and most of the glazed nose section. The Mk V (Type 160) was used primarily in the Middle East and Far East. The Blenheim served as

8755-420: The publicity of the fighter squadrons. From July to December 1940, Blenheims raided German-occupied airfields both in daylight and at night. Although most of these raids were unproductive, there were some successes; on 1 August five out of twelve Blenheims sent to attack Haamstede and Evere ( Brussels ) were able to bomb, damaging (50%, 40% and 10%) three Bf 109Es of II./JG 27 at Leuwarden and apparently killing

8858-463: The question of converting the Type 142 into a medium bomber. The Air Ministry quickly formalised Specification B.28/35 for prototypes of a bomber version; the Type 142M (M for military). One change between the Type 142M bomber and its Type 142 predecessor was the repositioning of the wing from a low-wing to a mid-wing position, which allowed for more internal space within the fuselage underneath

8961-551: The rear fuselage. Flexible, self-sealing liners had been fitted to the fuel tanks but they were still not fully protected against the 0.79 in (20 mm) MG FF cannon carried by the Luftwaffe ' s Bf 109 and Bf 110 fighters. Blenheim squadrons were still in immediate and high demand after their withdrawal from France as part of the British action during the Norwegian campaign . Typically operating from bases in

9064-511: The same period, losing 52 aircraft; by the end of the year, 698 ships had been attacked and 41 of these sunk for the loss of 123 aircraft. The Bristol Blenheim was used by both Bomber and Fighter Commands . About two hundred Mk I bombers were modified into Mk IF long-range fighters with 600 (Auxiliary Air Force) Squadron , based at Hendon , the first squadron to take delivery in September 1938. By 1939, at least seven squadrons were operating them as fighters, increasing to about 60 squadrons within

9167-419: The ships spotted on the previous day. The raid was a failure, only nine aircraft attacked, and only superficial damage was done to the cruiser Emden , when one of No. 107 Squadron's Blenheims crashed into the cruiser, killing 11 crewmen. RAF Coastal Command were soon using the Blenheim with the stated mission of protecting British shipping convoys off the east coast. Shortly after the conflict's start,

9270-480: The single-engined Heinkel He 70 , and Rothermere wanted the prestige of being able to claim to have the fastest civilian aircraft. Rothermere also intended to encourage businesses and key figures to make greater use of civil aviation and to demonstrate to the British Air Ministry how their fighter aircraft may not be able to match modern transport aircraft, which may be easily converted to, or used as

9373-481: The type was also flown internationally from Stuttgart to Seville ; this route was part of the South American mail service provided by Luft Hansa which continued via Bathurst , The Gambia to Natal , Brazil , using Junkers Ju 52/3m and Dornier Wal flying boats. All remaining aircraft were transferred to the Luftwaffe during 1937. Starting in 1935, the Luftwaffe operated the He 70, initially as

9476-620: The war in total – in the early years of World War II . The He 70 was essentially scaled down to produce the He 112 fighter which lost out on competition against the Messerschmitt Bf 109 , but was nonetheless built in small numbers. An He 70 was exported to Japan for study and inspired the Aichi D3A ("Val") carrier-launched light bomber. This aircraft shared the He 70's distinctive, low-mounted elliptical wing. Beverley Shenstone , R.J. Mitchell's aerodynamic advisor denied that

9579-408: The weight of the released bombs. Because there was no way to predict how long it would take for the bombs to force the doors open, bombing accuracy was consequently poor. The bomb bay could be loaded using a hand-operated winch incorporated into the fuselage. To achieve its relatively high speed, the Blenheim used a very small fuselage cross-section, with its upper front glazing all at one angle in

9682-437: The wing tips while the camber corresponded directly with wing thickness and determined mathematically. The wing was composed of wood and had a twin- spar structure that extended into two box-shaped recesses in the fuselage where they were secured to the main frames using bolts. The ribs were made of spruce and the webs were of laminated birch while the exterior of the wing was covered in plywood . The torsional stiffness

9785-599: Was a severe blow to the Imperial Japanese Army Air Force . The Air Ministry's replacement for the Blenheim as a daylight bomber, another Bristol design, the Buckingham , was overtaken by events and changes in requirements, and considered inferior to the de Havilland Mosquito , and as such did not see combat. The final ground-attack version – the Blenheim Mk V – first equipped 139 Squadron in June 1942. Eventually thirteen squadrons – mainly in

9888-446: Was dispatched on a counter-attack upon German forces as they broke through defensive lines: 40 out of 71 aircraft were lost in this sortie. This is claimed to be the highest ever losses known to the RAF. Further action by Blenheims of Bomber Command that day sustained a 25% aircraft loss despite a high level of British fighter cover. Shortly thereafter, the mostly-depleted squadrons were withdrawn to Britain. Around 50 Blenheims supported

9991-412: Was distinct from that of those of the rival aircraft manufacturer Junkers , possessing greater aerodynamic performance for the fuselage section in proportion to its usable cabin space. The mounting of the wing in relation to the fuselage was such that the wing's upper surface and the side of the fuselage formed a relatively obtuse angle that had a pronounced anhedral that progressed into a dihedral in

10094-405: Was fitted to some aircraft in use as night fighters; these were the first British fighters to be equipped with radar. The Blenheim had been selected as the first aircraft to be adapted for this role as its fuselage was sufficiently roomy to accommodate the additional crew member and radar apparatus. Their performance was marginal as a fighter but they served as an interim type pending availability of

10197-513: Was mounted on 13 August 1940 against a Luftwaffe airfield near Aalborg in north-western Denmark by twelve aircraft of 82 Squadron . One Blenheim returned early (the pilot was later charged but was killed on another operation before a court martial was held); the other eleven, which reached Denmark, were shot down, five by flak and six by Bf 109s. Blenheim units had also been formed to carry out long-range strategic reconnaissance missions over Germany and German-occupied territories. In this role,

10300-403: Was rebuilt from a scrapped Bolingbroke over a 12-year period, only to crash at an airshow at Denham within a month of completion in 1987. Heinkel He 70 The Heinkel He 70 Blitz ("lightning") was a fast monoplane aircraft designed and produced by the German aircraft manufacturer Heinkel Flugzeugwerke . It was the first Schnellbomber operated by the Luftwaffe . Development of

10403-427: Was relatively high on account of the continuous wing covering. A spindle -shaped monocoque fuselage composed of duralumin was adopted. The longerons , bulkheads and stiffeners were all open channel sections; the combination of frame bulkheads and longitudinal channel sections permitted the presence of unobstructed compartments. The cabin extended across four primary bulkheads; all channels in close proximity to

10506-438: Was subsequently superseded by an increased top speed of 320 kmph. Around this time, Germany was already experimenting with producing high-speed mail planes that could compete with American offerings; furthermore, it was generally recognised that the speed of an aircraft was a major competitive advantage over other modes of transportation. It was also recognised that to achieve such performance, engine power alone would not suffice,

10609-434: Was the fully retractable main undercarriage that made use of the space in between the wing spars. The ailerons were precisely balanced to prevent flutter . The cantilever flight control surfaces were elliptical in planform. No wind tunnel testing was conducted prior to the completion of the first He 70 due to alleged calculation complications between models and real aircraft; several wind tunnel tests were performed after

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