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138-716: The Fighter Interception Unit was initially set up to evaluate technological advances such as aircraft interception (AI) radar and other operational innovations, to counter increasing night raids by the Luftwaffe . The unit was formed at RAF Tangmere in April 1940 under the command of Squadron Leader George Philip (Peter) Chamberlain, with a strength of 5 Blenheims equipped with the latest AI Mk III radars. Operations initially consisted of daytime practice interceptions and operational night defence flights. The night fighter Blenheims were directed several times to possible targets, in

276-707: A C-scope display on the CRT. In the post-war period the Mk. X became one of the UK's most widely used fighter radars, largely because a lack of foreign exchange to purchase newer designs, and the poor economy in general which required the RAF to have a "make do" attitude. The Mk. X would go on to equip the first jet-powered night fighters, including the Vampire NF.10 and Meteor NF.11 . Small numbers remained in service as late as 1957. For

414-508: A Junkers Ju 88 A-5 near Chichester . Several advanced versions of the Mk. IV were also produced, which offered direct readings for the pilot and options to allow use in single seat aircraft. However, these developments were overtaken by the rapid improvements in microwave systems, and both the Mark V and Mark VI saw only limited production and service. In February 1940, John Randall and Harry Boot at Birmingham University successfully ran

552-721: A de Havilland Mosquito and a Bristol Beaufighter fighter intercepting Heinkel He 111 bombers flying from Dutch airbases and carrying out airborne launches of the V-1 flying bomb . The FIU operators on the Wellington would search for the He 111 aircraft climbing to launch altitude, then direct the Beaufighter to attack the bomber, while the Mosquito would attempt to intercept the V-1 if it

690-736: A friendly fire incident, killing him and destroying the only prototype. This so greatly delayed the program that the Air Ministry asked Jackson to test the US SCR-720 unit as a stop-gap measure. This proved to be able to pick the bomber from the window, and work on the Mk. IX was given low priority while the UK version of the SCR-720, known as the Mk. X, was purchased. With the night fighter force certain of its ability to continue operating successfully if needed, Bomber Command received clearance to begin using window on 16 July 1943. Work on

828-401: A 24-inch search light in the 'dustbin' turret of a DWI Wellington testing it from January 1941. This prototype substituted batteries for the engine and generator setup to reduce weight and this carried forward into production Leigh light-equipped Wellingtons Together with accurate radar altimeters, Wellingtons could fly safely down to 50 ft, illuminating the target submarine at around half

966-439: A German Messerschmitt Bf 110 night-fighter attacked a Wellington returning from an attack on Münster , causing a fire at the rear of the starboard engine. The second pilot, Sergeant James Allen Ward ( RNZAF ) climbed out of the fuselage, kicked holes in the doped fabric of the wing for foot and hand holds to reach the starboard engine and smothered the burning upper wing covering. He and the aircraft returned home safely and Ward

1104-582: A Mosquito NF.II was upgraded to the Mk. VIII, serving as the pattern for the Mosquito NF.XII. Starting in December, Beaufighter units were upgraded to the similar Mk. VIIIA, an interim type awaiting production quantities of the VIII. Although the precise origins of the concept are unknown, on 8 March 1941 Lovell mentions the concept of "lock-follow" for the first time in his notes. This was a modification to

1242-431: A corresponding works order was issued for the Wellington. On 15 June 1936, K4049 conducted its maiden flight from Brooklands. Vickers chief test pilot Joseph Summers flew K4049 on its first flight, accompanied by Wallis and Trevor Westbrook. The aircraft soon came to be widely regarded as being an advanced design for its era and proved to have considerable merit during its flight trials. On 19 April 1937, K4049

1380-594: A cruising speed of 125 knots carrying 1,500 lb of bombs or depth charges. It was used for anti-submarine operations; on 6 July 1942, a Wellington sank its first enemy vessel. In 1944, Wellingtons of Coastal Command were sent to Greece and performed various support duties during the British intervention in the Greek Civil War . A few Wellingtons were operated by the Hellenic Air Force . While

1518-521: A directive by the Air Staff to replace them. At the same time a development contract was placed with Nash & Thompson for a turret that could be used for both front and rear positions. The resulting FN.5 was also used on Short Stirling and Avro Manchester Due to the specialised nature of increasingly advanced turrets, these were treated as ancillary equipment, being designed and supplied independently and replacing Vickers' own turrets developed for

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1656-495: A formation of Wellingtons to penetrate strongly defended hostile airspace was validated. On 14 December 1939, 12 Wellingtons of No. 99 Squadron conducted a low-level raid upon German shipping at the Schillig Roads and Wilhelmshaven . Encountering enemy fire from warships, flak , and Luftwaffe aircraft, the Wellington formation lost five aircraft, along with another that crashed near its base, while only one enemy fighter

1794-519: A greater quantity produced than any other British bomber. On 13 October 1945, the last Wellington to be produced rolled out. The Wellington Mk I was quickly superseded by improved variants. Improvements to the turrets and the strengthening of the undercarriage quickly resulted in the Wellington Mk IA . The Mk IA was specified to be based on the Merlin X engined Wellington Mk II design and

1932-661: A ground-mapping display. The AI.18R added modes to support the Red Top missile . The AI Mark 20 was an X-band radar developed by EKCO Electronics for single seat fighters. Code named "Green Willow" by the MoS, it was intended to be a backup system to the AI.23 being developed for the English Electric Lightning (see below). It is believed that the 1953 contract was awarded to EKCO due to their already existing work on

2070-440: A helical scan instead of spiral. The radar antenna was spun around a vertical axis through an entire 360 degrees 10 times a second, with the transmitter switching off when the antenna was pointed back towards the aircraft. This provided a 150 degree scan in front of the aircraft. As it spun, the antenna slowly nodded up and down to provide altitude coverage between +50 and -20 degrees. The resulting scanning pattern naturally produced

2208-586: A large number of aircraft destroyed on the ground. In late 1944 the Fighter Interception Development Squadron (of the Night Fighter Development Wing) carried out operational trials at RAF Ford (and later Manston) under the code name Operation Vapour to counter Heinkel He 111 H-22 aircraft of III/ KG 53 air launching V-1 flying bombs. A radar-equipped Vickers Wellington was modified for use by

2346-723: A lock at as much as 75° in roll. The dish was unique in that it included a fibreglass ring around the outer rim as a stiffener. Mk. 18 was able to detect the English Electric Canberra at 28 nautical miles (52 km) at altitudes over 20,000 feet (6,100 m) and a closing speed of 900 knots (1,700 km/h). It could detect the Boeing B-47 at 38 nautical miles (70 km) under the same conditions, and could lock-follow after closing to about 25 nautical miles (46 km). When set to its longest range, 100 miles (160 km), it also offered sea surface search, and

2484-780: A memo on the topic in 1936, indicating that the Germans would likely begin a night campaign if the daylight campaign went as poorly as he believed it would due to Chain Home. The obvious solution would be to mount a small radar on the aircraft, one able to cover the range between the Dowding system's 5-mile accuracy and the average visual spotting range, about 500 to 1,000 feet (150–300 m). As early as August 1936 "Taffy" Bowen , one of Robert Watson-Watt 's hand-picked radar development team, personally requested that he be allowed to start research into an airborne radar set for this role. This

2622-475: A mile away just as the air-to-surface-vessel (ASV) radar lost the target among returns from the water's surface. In late 1944, a radar-equipped Wellington XIV from 407 Sqn. RCAF was modified for use by the RAF's Fighter Interception Unit as what would now be described as an airborne early warning and control aircraft. It operated at an altitude of 4,000 ft (1,200 m) over the North Sea to control

2760-465: A mixture of Wellington Mk I and Mk IA aircraft. On 4 September 1939, less than 24 hours after the commencement of hostilities, a total of 14 Wellingtons of No. 9 and No. 149 Squadrons, alongside a number of Bristol Blenheim aircraft, performed the first RAF bombing raid of the war, against German shipping at Brunsbüttel . The bombing of the harbour had not been permitted by Chamberlain's War Cabinet for fear of injuring civilians. The effectiveness of

2898-513: A reappraisal of the strength of its armed forces, especially that of the Royal Air Force". By 1936, the need for a high priority to be placed on the creation of a large bomber force, which would form the spearhead of British offensive power, had been recognised; accordingly, a new command organisation within the RAF, Bomber Command , was formed that year to deliver upon this requirement. In early 1936, an initial prototype, K4049 , which

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3036-514: A receiver fit to a Handley Page Heyford bomber, with an antenna consisting of a wire strung between the fixed landing gear . A working transmitter was first fit to the Heyford and flew in March 1937. In spite of this success, the system's antennas were still too large to be practical, and work continued on versions working at shorter wavelengths. A new system working at 1.25 m (220 MHz)

3174-593: A reshaped elevator and deepened fuselage which accommodated a larger bombload and the increased crew from four to five members. Other changes made included the adoption of a retractable tailwheel and constant-speed propellers ; the Air Ministry also requested the adoption of a Nash & Thompson -design ventral turret in place of the Vickers design. On 23 December 1937, the first production Wellington Mk I , L4212 , conducted its first flight, followed by an intensive flight programme. Flight trials with L4212 confirmed

3312-421: A second on 13 January. In the latter the aircraft flew below the safe 35 ft altitude and was caught in the explosive blast though remained flyable. The hoop was an aluminium coil in an aerodynamic balsa case; turrets were faired over and unnecessary equipment removed to reduce weight. The first mine detonation unit No. 1 GRU at RAF Manston was joined by a second (No. 2 GRU) at RAF Bircham Newton . To protect

3450-520: A separate squegging oscillator was used to produce pulses of the carrier signal using a timer. This timer also muted down the receiver, solving the ringing issue. Minimum range was reduced to about 400 feet. The resulting AI Mk. IV went into production in July 1940 and all units were sent to newly arriving Bristol Beaufighters . The Beaufighter/AI Mk. IV achieved its first victory on the night of 15/16 November 1940, when an aircraft from No. 604 destroyed

3588-451: Is a British term for radar systems used to equip aircraft with the means to find and track other flying aircraft. These radars are used primarily by Royal Air Force (RAF) and Fleet Air Arm night fighters and interceptors for locating and tracking other aircraft, although most AI radars could also be used in a number of secondary roles as well. The term was sometimes used generically for similar radars used in other countries, notably

3726-467: Is a British twin-engined, long-range medium bomber . It was designed during the mid-1930s at Brooklands in Weybridge, Surrey . Led by Vickers-Armstrongs ' chief designer Rex Pierson , a key feature of the aircraft is its geodetic airframe fuselage structure, which was principally designed by Barnes Wallis . Development had been started in response to Air Ministry Specification B.9/32, issued in

3864-598: Is owned by Brooklands Museum at Brooklands , Surrey. Built at Brooklands and first flown in November 1939, this aircraft took part in the RAF's daylight bombing raids on Germany early in the Second World War but later lost power during a training flight on 31 December 1940 and ditched in Loch Ness . All the occupants survived except the rear gunner, who was killed when his parachute failed to open. The aircraft

4002-571: Is the AI.24 radar of the Tornado ADV . These radars were often given common names as well, and generally better known by these; the AI.24 is almost universally referred to as "Foxhunter". Other widely used post-war examples include the AI.18 used on the de Havilland Sea Vixen , and the AI.23 Airpass on the English Electric Lightning . This article will use Mk. or AI. depending on which is most commonly used in available references. In order to provide

4140-634: The Bristol Beaufighter by early 1941. The Mk. IV helped end the Blitz , the Luftwaffe ' s night bombing campaign of late 1940 and early 1941. Starting with the AI Mk. VII , AI moved to microwave frequencies using the cavity magnetron , greatly improving performance while reducing size and weight. This gave the UK an enormous lead over their counterparts in the Luftwaffe , an advantage that

4278-651: The Bristol Hercules and the Rolls-Royce Merlin engines. Recognisable characteristics of the Wellington include the high aspect ratio of its tapered wing , the depth of its fuselage and the use of a tall single fin on its tail unit, which reportedly aided in recognition of the type. The Wellington typically had a crew of five, the bomb-aimer being located in the aircraft's nose. The Wellington could be fitted with dual flight controls, and specialised dual-control conversion sets were developed for

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4416-510: The Fairey Fireflash missile illumination radar. AI.20 was significantly simpler than the AI.23, being much closer in design to an upgraded AI.17 than the much more advanced AI.23. It used a simple spiral scan system driven at 10,000 RPM, scanning out to 45 degrees and then back every 2.25 seconds. Testing started in 1955, and the AI.20 demonstrated its ability to lock-on to a Hawker Hunter sized target at 7 miles (11 km) 95% of

4554-536: The Fairey Firefly , which had the size to carry a radar operator and the performance to operate as a fighter. Some were also used on the Mosquito. Considerably later, a single Meteor, EE348 , was fit with an APS-4 in a nose mounting as a test vehicle. The APS-6 was a modification of the APS-4 specifically for the interception role. It replaced the side-to-side scan with a spiral-scan system largely identical to

4692-571: The Fleet Air Arm , the TRE developed a series of AI radars operating at the even shorter 3 cm wavelength, the X band , which further reduced the size of the antennas. The original model was the Mark XI, followed by the improved Mark XII and lightened Mark XIII. It is not clear if any of these models saw service, and few references mention them even in passing. These designations were given to

4830-526: The H2S radar project and was replaced by Arthur Ernest Downing. This delayed the project just long enough that it got caught up in a great debate that broke out in the summer of 1942 about the use of window , today known as chaff . Window caused false returns on radar displays that made it difficult to tell where the bombers were amid a sea of blips. Bomber Command had been pressing to use window over Germany to reduce their losses, which were beginning to mount as

4968-624: The Hawker Tempest V, where it tested Monica radar (known officially by the RAF as ARI 5664 and by the US military, as AN/APS 13), a range-determining, tail warning system, for night use. This special flight of Tempest V fighters was formed to counter the V-1 "Flying bombs" which had begun falling on south-east England. The flight operated mainly by night and claimed 86 ½ V-1s destroyed before being absorbed into No. 501 Squadron RAF . The FIU's Squadron Leader Joseph Berry claimed 52 V-1s to become

5106-689: The Leigh light was deployed through the mounting for the absent FN9 ventral turret . The Gloster and AWA contracts were transferred to Shadow factories in the north-west. In the late 1930s, Vickers built Wellingtons at a rate of one per day at Weybridge and 50 a month at Broughton in North Wales . Many of the employees on the production lines were only semi-skilled and new to aircraft construction. Peak wartime production in 1942 saw monthly rates of 70 at Weybridge, 130 at Broughton and 102 at Blackpool . Shadow factories were set up to produce parts for

5244-606: The Panavia Tornado ADV , an interceptor development of the Tornado that provides long-range defense against bomber-like targets. Development of the ADV began in 1976 and the radar system contract was eventually won by a curious combined bid; Marconi and Elliot Automation would provide most of the design, while Ferranti built the transmitter section and Antenna Platform. Vickers Wellington The Vickers Wellington

5382-411: The Rolls-Royce Merlin engine. In spite of a traditional preference of the establishment to strictly adhere to the restrictive tare weight for the aircraft established in the tender, both Pierson and Wallis firmly believed that their design should adopt the most powerful engine available. Perhaps in response to pressure from Vickers, the Air Ministry overlooked, if not openly accepted, the removal of

5520-551: The Royal Aircraft Establishment , Farnborough , the proposed structure demonstrated not only the required strength factor of six, but reached 11 without any sign of failure, proving the geodetic airframe to possess a strength far in excess of normal levels. This strength allowed for the structure design to be further developed to reduce the size of individual members and adopt simplified standard sections of lighter construction. Vickers studied and compared

5658-672: The AI.20 primarily in the details of the operation and visual presentation. This was later upgraded to the Mark 2 model that equipped the V-force for most of its lifetime. As the Javelin ran into delays, it was decided to increase the useful life of the existing Meteor and Vampire night fighters with a new radar. After considering three US designs, they chose the Westinghouse AN/APS-57 . Its 200 kW transmitter improved range to as much as 25 miles (40 km) although this

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5796-670: The African cost with 26 Squadron SAAF based in Takoradi , Gold Coast (now Ghana ), and the Free French 344 Squadron from Dakar . Specialised "Directional Wireless Installation" (DWI), a cover story for the true purpose of the hoop variants, fitted with a 48 ft (15 m) diameter metal hoop, were used for exploding German magnetic mines by generating a powerful magnetic field as it passed over them. The first successful mine detonation occurred on 8 January 1940 followed by

5934-445: The Air Ministry accepted the proposed changes. Other refinements of the design had also been implemented and approved, such as the adoption of variable-pitch propellers , and the use of Vickers-produced gun turrets in the nose and tail positions. By December 1936, the specification had been revised to include front, rear, and midship wind-protected turret mountings. Other specification changes included modified bomb undershields and

6072-611: The Bellman hangar was relocated and restored until taken off display and moved back into the latter building on 25 July 2017. The aeroplane is the centre-piece of the 'Brooklands Aircraft Factory' exhibition about the aircraft industry at Brooklands, which was formally opened on 13 November 2017. Wellington T.10 serial number MF628 is held by the Royal Air Force Museum . It was delivered to RAF No.18 MU (Maintenance Unit) for storage at RAF Tinwald Downs , Dumfries , as

6210-585: The Blenheim at an altitude of 700 feet and landed at Tangmere just after midnight. The unit was later also equipped with the Hawker Hurricane and were the first unit to receive the new Bristol Beaufighter (on 12 August 1940), still stationed at RAF Tangmere. Between 1940 and June 1944, some 21 victories were claimed by the FIU. A FIU detachment was at RAF Newchurch to complement No. 150 Wing RAF with

6348-547: The British Air Ministry invited Vickers to tender for the recently issued Specification B.9/32 , which sought a twin-engine medium daylight bomber. In response, Vickers conducted a design study, led by Chief Designer Rex Pierson . Early on, Vickers' chief structures designer Barnes Wallis proposed the use of a geodetic airframe , inspired by his previous work on airships and the single-engined Wellesley light bomber . During structural testing performed at

6486-526: The Dornier lurched to starboard and fell away, 5 miles south of Bognor Regis . The aircraft, a Dornier 17Z of 2 Staffel , Kampfgeschwader 3 , crashed into the sea and the crew was later rescued. The Blenheim was so close to the Dornier during the attack that the cockpit perspex was covered in oil, resulting in Ashfield losing control and the Blenheim flipping onto its back. He was able to regain control of

6624-551: The FAW.6. The last AI.17-equipped Javelin FAW.9's ended their service in Singapore in 1968. Having lost the contest for the Javelin, GEC submitted an updated version of the Mk. 16 for the contest for the de Havilland Sea Vixen . This produced the Mk. 18. Mk. 18 operated in the X band with a 180 kW peak power, using a 29 inches (740 mm) parabolic dish that could be pointed ±100° in azimuth, +50/-40° in elevation, and could keep

6762-738: The Fighter Interception Unit as one of the first Airborne Early Warning and Control (AEW&C) aircraft. It operated at an altitude of 4,000 feet over the North Sea to control Mosquito night fighters intercepting the Heinkel He 111s flying from Dutch airbases and carrying out airborne launches of the V-1 flying bomb. The modus operandi typically involved the Heinkels leaving bases in the Netherlands and flying out over

6900-617: The Fighter Interception Unit from May to November 1944, where they were used to evaluate suitability for high-altitude fighter operations. A two-seat night fighter version – the Welkin NF Mk II – was also evaluated but only two were produced was not ordered into production. During the closing months of the war the BSDU claimed four victories, the FIDS two victories and the FEF eight victories plus

7038-531: The German defensive network improved. Fighter Command was concerned that if Bomber Command used it over Germany, the Germans would return the favour and use it over the UK. A series of tests carried out in September 1942 by Wing Commander Derek Jackson suggested that some changes to the display systems might solve the problems with window on the Mk. VIII. At this point it was suggested that the Mk. IX might ignore

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7176-485: The Mk IC, such as higher cruising and top speeds, increased all-up weight or alternatively greater range and a raised ceiling. The Vickers Wellington was a twin-engined long-range medium bomber , initially powered by a pair of Bristol Pegasus radial engines, which drove a pair of de Havilland two-pitch propellers. Various engines and propeller combinations were used on variants of the aircraft, which included models of

7314-419: The Mk. IV, but as the timebase now spun, they drew short arcs on the display during the period the antenna was pointed in that direction. Like the Mk. IV, the distance from the center of the CRT indicated the range. As the target moved closer to the centreline of the aircraft, the beam spent more time painting the target, and the arc spread out, becoming a ring when dead ahead. First introduced in March 1941, it

7452-482: The Mk. IX continued, but it never saw operational service. In testing in 1944 it was found to be marginally better than the US SCR-720, but with the SCR-720 expected to arrive at any moment, the demand for another radar was not pressing. Instead, the Mk. IX was given more time to mature. Further development led to more testing in 1948, but it was again passed up for production and cancelled the next year. The Mark X

7590-579: The Mk. VII, requiring very large amount of aircraft space for the install. Conversions on the Beaufighter began in December 1941. This run was followed by the production Mark VIII that included the new "strapped magnetron" of 25 kW, improving range to about 5.5 miles (8.9 km). This version also had several major clean-ups in the electronics, support for IFF Mark III which caused a sunrise pattern to appear when aimed at friendly aircraft, and beacon tracking allowing it to home in on ground-based transmitters emplaced by friendly units. In September 1942

7728-430: The Mk. X to soldier on while a definitive jet-powered night fighter evolved. This effort underwent similar delays and setbacks before finally emerging as the Gloster Javelin . Two radar sets competed for the design, the Mk. 16 and Mk. 17. The later went into production, and is better known as the AI.17. General Electric Company 's Mark 16 was one of two similar designs competing to equip the Gloster Javelin . The contest

7866-469: The NF.14, which started deliveries in June. Likewise the de Havilland Venom received the Mk. 21 to become the Venom NF.3, also entering service in June, but was withdrawn by the end of 1957. The Sea Venom flew the Mk. 21 until 1959, and in second-line duty until 1970. The Mark 22 was the British version of the US AN/APQ-43 , This consisted of two radar antennas driven from a common magnetron transmitter. One used spiral-scan to search for targets, while

8004-452: The North Sea at a height of less than 300 feet. Once the Heinkels neared the East Anglian coast they would increase speed and release their flying bombs before turning for home at low level. To assist in detecting the Heinkels the Fighter Interception Development Squadron borrowed a Coastal Command Wellington equipped with a modified ASV Mk VI radar set and PPI to act as Airborne Early Warning and Control. After trials, low level night patrols off

8142-504: The RAF on the outbreak of war and used by 75 Squadron ). In October 1938, the Mk I entered service with 9 Squadron . The Wellington was initially outnumbered by the Handley Page Hampden (also ordered by the Ministry to B.9/32) and the Armstrong Whitworth Whitley (to B.34/3 for a 'night' bomber) but outlasted both rival aircraft in service. The Wellington went on to be built in 16 variants and two post-war training conversions. The number of Wellingtons built totalled 11,462 of all versions,

8280-417: The RAF's first long-range bombers operating in the Far East with the arrival of 99 and 215 Squadrons RAF, providing much needed bombing support for the next two years before being withdrawn and replaced by Liberators in the summer of 1944. Wellingtons were also used for maritime patrols over the Indian Ocean by 36 , and later, 203 Squadrons RAF. The Wellington also served in anti-submarine duties off

8418-462: The RAF's top scorer against the flying bombs. On 23 August 1944 the FIU became the Fighter Interception Development Squadron (FIDS). By the latter war years the unit had become an element of the Night Fighter Development Wing (NFDW), which also included the Bomber Support Development Unit (BSDU) and the Fighter Experimental Flight (FEF), which specialised in "Ranger" (daylight intruder ) operations with Mosquitoes . Two Westland Welkin s served with

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8556-460: The Sussex coast at 10,000 ft (3,000 m). They were directed to a possible intercept by the controller at Poling Chain Home radar station who reported an incoming raid. Sgt. Leyland reported a response on the AI at a range of 8,000 feet and presently P/O Morris made a visual sighting of a Dornier Do 17 to port and below the Blenheim. Ashfield closed the distance to 400 feet and then opened fire. Strikes were observed on fuselage and engines,

8694-459: The US AN/APS-4 and AN/APS-6 radars, small under-wing X band radars used primarily by naval aircraft. The APS-4 was originally developed as the ASH, a forward-aimed surface-search system. It was packaged into an underwing pod so it could be used on single-engine aircraft like the TBM Avenger . It proved to have a useful interception function, and was modified to be able to scan up and down as well as just side to side. The Fleet Air Arm mounted it on

8832-503: The US. AI radar stands in contrast with ASV radar , whose goal is to detect ships and other sea-suface vessels, rather than aircraft; both AI and ASV are often designed for airborne use. The term was first used circa 1936, when a group at the Bawdsey Manor research center began considering how to fit a radar system into an aircraft. This work led to the AI Mk. IV radar , the first production air-to-air radar system. Mk. IV entered service in July 1940 and reached widespread availability on

8970-413: The Wellington all over the British Isles. In October 1943, as a propaganda and morale-boosting exercise, workers at Broughton gave up their weekend to build Wellington number LN514 rushed by the clock. The bomber was assembled in 23 hours 50 minutes, and took off after 24 hours 48 minutes, beating the record of 48 hours set by a factory in California. Each Wellington was usually built within 60 hours. It

9108-586: The Wellington was its geodetic construction, devised by aircraft designer and inventor Barnes Wallis. The fuselage was built from 1,650 elements, consisting of duralumin W-beams which formed into a metal framework. Wooden battens were screwed to the beams and were covered with Irish linen ; the linen, treated with layers of dope , formed the outer skin of the aircraft. The construction proved to be compatible with significant adaptations and alterations including greater all-up weight, larger bombs, tropicalisation and long-range fuel tanks. The metal lattice gave

9246-449: The Wellington was superseded in the European Theatre as more four engined bombers arrived in service, it remained in operational service for much of the war in the Middle East and still formed a key part of the RAF's Mediterranean forces as the allies moved into Italy , with some still serving in March 1945 carrying out bombing raids and dropping supplies to partisans across Southern Europe. In 1942, Wellingtons based in India became

9384-437: The Wellington's design was influenced by the issuing of Specifications B.3/34 and B.1/35, the latter of which led a larger bomber aircraft, the Vickers Warwick With detail design work on both being done at same time and both aircraft using geodetic-inspired construction there was commonality in components. The production model Wellington was a complete redesign, resulting in a lengthened nose for turret and bomb aimer's position,

9522-456: The aerodynamic stability initially encountered by K4049 , but also revealed the aircraft to be nose-heavy during dives, which was attributed to the redesigned elevator. Modifications, including the linking of the flaps and the elevator trim tabs , were tested on L4212 and resolved the problem. In August 1936, an initial order for 180 Wellington Mk I aircraft, powered by a pair of 1,050 hp (780 kW) Bristol Pegasus radial engines ,

9660-417: The aircraft at an all-up weight of 30,500 lb (13.8 t), which aviation author C.F. Andrews described as "a very high figure for a medium bomber of those days". During the development phase of the aircraft, as C F Andrews puts it "the political and military climate of Europe was changing rapidly. The threats of the dictators of Germany and Italy began to exert pressure on the British Government to make

9798-491: The aircraft, one with each of the selected powerplants, were submitted to the tender. In September 1933, the Air Ministry issued a pilot contract for the Goshawk-powered version. In August 1934, Vickers proposed to use either the Pegasus or the sleeve-valve 9-cylinder radial Bristol Perseus engines instead of the evaporative-cooled Goshawk, which promised improvements in speed, climb rate, ceiling, and single-engine flight capabilities without any major increase in all-up weight;

9936-437: The aircraft. The Vickers-built ventral turret of the Mk I was replaced by a Nash & Thompson-built FN.25 counterpart as standard. The squadrons were critical of the ventral turrets; when extended they slowed the aircraft by 10 mph, the single narrow window pane limited visibility and sometimes froze in place and had to be jettisoned. The ventral turrets were not fitted after the first batch of Wellington IA A novelty of

10074-433: The early days of ground-controlled interception (GCI) to acquire and then maintain a radar contact and finally to intercept target proved a very difficult task. On the night of the 22/23 July 1940 they achieved the first aircraft-interception radar kill in history. A Blenheim Mk IF flown by Flying Officer G. Ashfield, with a crew of Pilot Officer G.E. Morris (Observer) and Sergeant R.H. Leyland (AI radar operator), patrolled

10212-426: The end of 1937, Vickers set about simplifying the manufacturing process of the aircraft and announced a target of building one Wellington per day. The geodetic design took longer to build than comparable aircraft using the more conventional monocoque approach, leading to some criticism of the Wellington. In addition it was difficult to cut holes in the fuselage for access or equipment fixtures; to aid manufacturing,

10350-546: The engine used was not the one originally intended. Despite the original specification, the Wellington was used as a night bomber in the early years of the Second World War , performing as one of the principal bombers used by Bomber Command . During 1943, it started to be superseded as a bomber by the larger four-engined " heavies " such as the Avro Lancaster . The Wellington continued to serve throughout

10488-427: The first cavity magnetron , eventually generating 1 kW at 9.8 cm (3,060 MHz). Supported by GEC, the device quickly developed into a practical 10 kW system, and several test units were available by May 1940. Microwave wavelengths are so much shorter than the Mk. IV's 1.5 m, fifteen times, that the dipole antennas required for reasonable gain were only a few inches long. This dramatically reduced

10626-424: The first flight of the type's effective prototype in 1936. On 15 September 2016, after having its outer wings removed the day before, N2980 was towed from the Bellman hangar in which it was restored and where it had been displayed for nearly 30 years. This move was the first time that 'R' for 'Robert' had moved on its undercarriage since its last flight in 1940. The aircraft was exhibited in a temporary building while

10764-410: The front and rear, the Wellington had no defences against attacks from the beam and above, as it had not been believed that such attacks were possible owing to the high speed of aircraft involved and the deflection shooting required. Unescorted day bombing was abandoned and Bomber Command decided to use the Wellington force to attack German communications and industrial targets instead. The Wellington

10902-435: The gunsight, as well as computer-calculated cueing information that located both the target and the proper position to fly to engage based on the selected weapon. For instance, when using missiles, the system guided the aircraft not toward its target, but a point behind it where the missile could be fired. This gave the system its name, AIRPASS , an acronym for aircraft interception radar and pilot's attack sight system. AI.23

11040-499: The headquarters staff at the University of Dundee attempted to develop their own solutions to the problem. This led to considerable strife and in-fighting between the two groups. The AI group was eventually broken up at the end of March 1940, leaving Bowen out of the AI effort. A solution was eventually provided by EMI who had developed a new type of transmitter that was not based on the common self exciting principle. Instead,

11178-412: The inclusion of spring-loaded bomb bay doors. The proposal had also been developed further, a mid-wing arrangement was adopted instead of a shoulder-mounted wing for greater pilot visibility during formation flight and improved aerodynamic performance, as well as a substantially increased overall weight of the aircraft. Design studies were also conducted on behalf of the Air Ministry into the adoption of

11316-440: The incoming bombers near to Heligoland and attacked the formation for much of the way home. Twelve of the bombers were destroyed and a further three were badly damaged. The Wellingtons shot down four aircraft. The action at Heligoland highlighted the Wellington's vulnerability to attacking fighters, possessing neither self-sealing fuel tanks nor sufficient defensive armament. The nose and tail turrets protected against attacks from

11454-418: The infamous 1957 Defence White Paper , but by this time the interim English Electric Lightning design, the P.1, had progressed to the point where development was undertaken anyway (along with TSR.2). This led to continued development of the AI.23 for this aircraft (and Mk. 20, see above), and it was given the official designation "ARI 5897". The system was mounted entirely in a single bullet-shaped housing that

11592-486: The installation of cabin heating and an astrodome . On 3 March 1939, L4250 , the prototype Mk II, performed its maiden flight; this had been delayed due to production delays of its Merlin X engines. Stability and balance problems were encountered during flight tests of the prototype, resulting in further changes such as the enlargement of the tailplane. By late 1939, the Mk II was capable of delivering superior performance to

11730-628: The maximum possible warning time of an incoming raid, the RAF's Chain Home (CH) radar stations had been positioned as far forward as possible, right on the coastline. These systems could only see targets in front of them, over the English Channel . Tracking over land fell to the Royal Observer Corps (ROC) using visual means. In testing it was found that the two different reporting systems provided information that varied enough to make tracking targets confusing and error prone, and

11868-574: The middle of 1932, for a bomber for the Royal Air Force. This specification called for a twin-engined day bomber capable of delivering higher performance than any previous design. Other aircraft developed to the same specification include the Armstrong Whitworth Whitley and the Handley Page Hampden . During the development process, performance requirements such as for the tare weight changed substantially, and

12006-618: The name "Crecy" was chosen for the type, and it was publicly displayed as such. On 15 August 1936, the aircraft was accepted for production. On 8 September 1936, the service name Wellington was adopted for the type; it fitted with Air Ministry nomenclature of naming bombers after towns and followed the Vickers Wellesley in referring to the Napoleonic War general Arthur Wellesley, the Duke of Wellington . On 12 December 1936,

12144-497: The north of the Netherlands were carried out by the Wellington with several Mosquito night fighters. For the night fighters to locate and keep station with the Wellington, the aircraft was fitted with a special homing beacon. Despite encouraging results, the Luftwaffe stopped air launches by mid January 1945 and the operational trials ended. Aircraft interception radar Aircraft interception radar , or AI radar for short,

12282-541: The one in the Mk. VIII. It also included a switch that reduced the scanning pattern to a 15 degree cone in front of the aircraft, producing a C-scope view used during the final approach. This was paired with a new and much smaller display, allowing it to be fit to smaller single-seat aircraft. It was widely used on the F6F Hellcat and F4U Corsair . With Mk. IX cancelled in 1949, the Ministry of Supply (MoS) allowed

12420-598: The performance of various air- and liquid-cooled engines to power the bomber, including the Bristol Pegasus IS2 , Pegasus IIS2, and Armstrong Siddeley Tiger radials, and the Rolls-Royce Goshawk I inline. The Pegasus was selected as the engine for air-cooled versions of the bomber, while the Goshawk engine was chosen for the liquid-cooled engine variant. On 28 February 1933, two versions of

12558-436: The purpose of performing training upon the type. The cockpit also contained provisions for heating and de-icing equipment, which was introduced on later models of the Wellington. The Wellington Mk I had a maximum offensive bomb load of 4,500 lb (2,000 kg), more than one-fifth of the aircraft's 21,000 lb (9,500 kg) all-up weight. Additional munitions and an expanded bombing capacity were changes in many of

12696-461: The radar could only see targets directly in front of the antenna, unlike the Mk. IV which could see anything in the entire volume in front of the aircraft. To solve this problem, the dish was mounted on a bearing system from Nash & Thompson that allowed it to be rotated in a spiral pattern. The cockpit display was modified to spin the timebase at the same speed as the antenna, 17 times a second. The display still produced blips similar to those on

12834-469: The raid was diminished by poor weather and high amounts of anti-aircraft fire. A pair of Wellingtons became the first aircraft to be lost on the Western Front . On 3 December 1939, 24 Wellingtons of No. 38, No. 115 and No. 147 Squadrons attacked the German fleet moored at Heligoland . The bombing commenced from high altitude and, while results of the bombing itself proved negligible, the ability of

12972-480: The receiver causing it to oscillate or ring for a period. While this powerful signal was dying down, reflections from nearby aircraft were lost in the noise. Numerous solutions had been attempted, but were of limited use. Starting in late 1939 the development team was asked to fit the existing Mk. III design, of limited use, to aircraft. This ended further attempts to address the minimum range issue while they worked on installations. While their development effort ended,

13110-403: The same target into a single track. Telephone operators, or "tellers", would then forward this information to group headquarters who would re-create the map, and then from group to the sector HQs who would give instructions to the fighter pilots. Due to delays in the flow of information between the various centres, and inherent inaccuracies in the reports coming from multiple sources, this system

13248-634: The second used conical scanning for tracking at close range. This was one of the earliest radars to offer track while scan (TWS) operation, although it did so through the use of what was essentially two radars. The APQ-43 was one of three designs also considered for updated versions of the Meteor and Venom, the others being the AN/APQ-35 which also had two-dish TWS, and the AN/APS-57. The -35 and -43 proved too large to install in these aircraft, forcing

13386-474: The selection of the -57 as the Mk. 21. The two TWS units proved interesting, and the -43 was considered for the Javelin. These were used in small numbers in the FAW.2 and FAW.6 models. Ferranti 's Mark 23 was an X band design originally designed for the modified Fairey Delta 2 proposed for the Ministry of Supply's Operational Requirement F.155 for a modern interceptor aircraft . Work on F.155 ended with

13524-565: The sheer volume of information could be overwhelming. Hugh Dowding addressed this through the creation of what is today known as the Dowding system , networking together the radars and observation centres by telephone to a central station. Here, in the Fighter Command 's "filter room" at RAF Bentley Priory , operators would plot the map coordinates sent to them on a single large map, which allowed them to correlate multiple reports of

13662-436: The size of the system, allowing it to fit entirely in the nose of the aircraft. While a team under Herbert Skinner developed the electronics, Bernard Lovell was put in charge of examining the use of a parabolic dish to improve the directionality of the signal. The resulting beam was so sharply focussed, spanning about 10 degrees, that it easily avoided ground reflections at even low altitudes. The narrow beam also meant that

13800-460: The speed and manoeuvrability necessary to keep up with the new generations of opposing fighter aircraft. The Vickers design put the gunner in a fixed seat behind the guns (a pair of .303 in (7.7 mm) Browning machine guns. ) which were mounted on a pillar with a Nash & Thompson control unit, and fired through a moving slot in the framed canopy. Although roomy, there were problems with malfunctions and poor gunnery and Vickers were given

13938-455: The spiral-scan system that allowed it to track targets automatically without further manual operation. This became known as AIF. "Freddie" Williams joined the effort, and by the autumn of 1941 the system was basically functional and plans began to introduce it as the Mark IX. Several unrelated events conspired to greatly delay further progress. On 1 January 1942 Lovell was sent to work on

14076-416: The structure considerable strength, with any stringer able to support a portion of load from the opposite side of the aircraft. Damaged or destroyed beams on one side could still leave the aircraft structure viable; as a result, Wellingtons with huge areas of framework missing were often able to return when other types would not have survived, leading to stories of the aircraft's "invulnerability". The effect

14214-417: The tare weight restriction, as between the submission of the tender in 1933 and the flight of the first prototype in 1936, the tare weight eventually rose from 6,300 lb (2.9 t) to 11,508 lb (5.220 t). The prescribed bomb load and range requirements were routinely revised upwards by the Air Ministry; by November 1935, figures within the Ministry were interested in the possibility of operating

14352-471: The time, excellent performance for that era. Nevertheless, as AI.23 began successful trials the same year, further work on AI.20 was cancelled. The next year the MoS published a requirement for a new tail warning radar for the V bomber force, replacing the original Orange Putter , and quickly chose the AI.20 as its basis. This was developed into the ARI-5919 Red Steer , which differed from

14490-702: The torpedo carrying aircraft onto their target were dubbed the "Snoopington". 38 Squadron, based in Shallufah, Egypt had a detachment of Wellingtons operating from RAF Luqa in Malta conducting anti-shipping operations with torpedoes during 1942. The Wellington was also adopted by RAF Coastal Command , in which it contributed to the Battle of the Atlantic . The Mark IC in Coastal had a endurance of over ten hours at

14628-649: The unarmed Wellingtons, Bristol Blenheims of No. 600 Squadron RAF flew escort during the Battle of France . One DWI was detached to the Middle East to act as the pattern for conversion of Wellingtons there. They were used for clearing the Suez Canal Zone and, later during the North Africa campaign , ports along the coast. For the development of what became the Leigh light, squadron leader Leigh fitted

14766-574: The ventral turret gun with two beam machine guns (either .303 Vickers K , or Browning ), was designated Wellington Mk IC and a Type number generated after the fact. In January 1938, design work on what would become the Wellington Mk II formally commenced. The principal change on this model was the adoption of the Merlin engine in place of the Pegasus XVIII; other modifications included hydraulic and oxygen system revisions along with

14904-414: The war in other duties, particularly as an anti-submarine aircraft with RAF Coastal Command . The Wellington was the only British bomber that was produced for the duration of the war, and was produced in a greater quantity than any other British-built bomber. The Wellington remained as first-line equipment when the war ended, although it had been increasingly relegated to secondary roles. The Wellington

15042-435: The war. Practical ASV radars were operational in 1940, but the AI developments proved much more difficult. It was not until 1939, with the war obviously looming, that the team was once again moved back to AI development full-time. A lingering problem was that the minimum range remained around 1,000 feet, too long to allow easy interception. This was due to the transmitter signal not turning off sharply, leaking through to

15180-428: The wartime variants of the Wellington, including the carrying of larger bombs. Defensive armament comprised the forward and tail turret gun positions, along with a retractable revolving ventral turret. Due to the high cruising speeds of the Wellington, it had been realised that fully enclosed turrets, as opposed to semi-enclosed or exposed turrets, would be necessary; the turrets were also power-operated to traverse with

15318-399: The window completely, as the light metal strips rapidly dispersed from the target being tracked, faster than the radar could follow. Further testing by Jackson demonstrated the opposite was true, and that the Mk. IX almost always locked-on to the window instead. Arthur Downing quickly implemented several changes to fix this problem. He was personally operating the system when he was shot down in

15456-595: Was a version of the Airpass dedicated to low-level flying, especially target detection, fitted to the Blackburn Buccaneer . Further development led to the terrain following radar used in the BAC TSR.2 . Many other variants were proposed for a wide variety of projects. The final radar in the UK series of AI designs to see deployment was the Mark 24, better known as "Foxhunter". Foxhunter was developed for

15594-510: Was able to detect and track a Bear-sized bomber at 40 miles (64 km), allowing the Lightning to accomplish fully independent interceptions with only the minimum of ground assistance. A version with fully automated guidance that would have flown the aircraft into range and fired its missiles automatically was cancelled in 1965. Further development of Airpass led to AI.23 Airpass II, code named "Blue Parrot" and also known as ARI 5930. This

15732-408: Was accurate to perhaps 5 miles (8.0 km). Within 5 miles the fighters would normally be able to spot their targets visually and complete the interception on their own. Interception rates over 80% was common, and on several occasions the system succeeded in getting every fighter launched into position for an attack. While the Dowding system proved invaluable inputs during daylight attacks, it

15870-626: Was approved, and the small aircraft interception team set up shop in Bawdsey Manor 's two towers. At the time, radar development was in its infancy and the other teams were working with long- wavelength transmitters operating around 7 meters. An efficient antenna requires it to be about 1 ⁄ 2 the wavelength or more, which demanded antennas at least 3 metres (9.8 ft) long, impractical for an aircraft. Additionally, available transmitters were large, heavy and fragile. The first AI experiments thus used ground-based transmitters and

16008-610: Was awarded the Victoria Cross . A unique feat for the type occurred on 23 December 1944 when a Me 163 Komet was shot down by rear gunner Gerry Elsyon, who was awarded the DFM. In 1942 the Wellington was adapted to conduct night anti-shipping torpedo attacks against German and Italian shipping in the Mediterranean. The torpedo-carrying Wellington was nicknamed the "Fishington", and the radar equipped Wellingtons that guided

16146-521: Was converted for night operations; on 25 August 1940, the type participated in the first night raid on Berlin . During the First 1,000 bomber raid , on Cologne on 30 May 1942, 599 out of 1,046 RAF aircraft dispatched were Wellingtons; of these, 101 were flown by Polish aircrew. During operations under Bomber Command, Wellingtons flew 47,409 operations, dropped 41,823 tons (37,941 tonnes) of bombs and lost 1,332 aircraft in action. In one incident,

16284-574: Was decided to produce another version of the Javelin with the US AN/APQ-43, which on paper appeared to be a better system. In RAF service the APQ-43 became the AI.22, and produced the Javelin FAW.2. In practice, the two systems offered similar performance and the AI.17 quality issues were soon addressed. Future versions of the Javelin mostly mounted the AI.17, although the AI.22 was also used on

16422-449: Was destroyed by an accident during a service test flight by Maurice Hare. The cause was the failure of the elevator 's horn balance due to excessive slipstream exposure, leading to the aircraft inverting and rapidly descending into terrain. It was destroyed in the crash, which also resulted in the death of the navigator, Smurthwaite. The horn balances were later deleted from the design and were not on production aircraft. Refinement of

16560-403: Was enhanced by the fabric skin occasionally burning off leaving the naked frames exposed. A further advantage of the geodetic construction of the wings was its enabling of a unique method for housing the fuel, with each wing containing three fuel tanks within the unobstructed space provided between the front and rear spars outboard of the engines. A disadvantage of the geodetic fuselage structure

16698-486: Was essentially useless against night raids. Once the enemy aircraft passed the coastline they could not be seen by the radars, and the ROC could not see at night except under ideal conditions with bright moonlight, no cloud cover, and considerable luck. Even when tracks could be developed, the difficulty of spotting a target from the cockpit of an aircraft while flying it at night proved to be equally difficult. Henry Tizard wrote

16836-434: Was eventually won by AI.17. AI.17 was essentially a version of the Mk. IXC with a number of detail cleanups and a 200 kW magnetron, as well as the ability to cue the "Blue Jay" missile that was then under development. It could detect a Javelin-sized target at about 20 nautical miles (37 km; 23 mi). AI.17 entered service with the Javelin in early 1956. Early sets had considerable reliability problems and it

16974-519: Was filmed for the Ministry of Information for a newsreel Worker's Week-End , and was broadcast in both Britain and America. It was the first time in aviation history that an aircraft manufacturer anywhere in the world had attempted such a feat with a metal aircraft of this scale. A total of 180 Wellington Mk I aircraft were built; 150 for the RAF and 30 for the Royal New Zealand Air Force (RNZAF) (which were transferred to

17112-487: Was found that the ground reflection created a sort of artificial horizon on the bottom of the display, a surprising side-effect which proved very useful. However, the limited power of the magnetron, about 5 kW, provided range of about 3 miles (4.8 km), not a great improvement over the Mk. IV. Performance of the system at low altitude was so improved over the Mk. IV that it was decided to make an initial run of 100 units out of what were essentially prototype systems as

17250-489: Was in theory to be able to be fitted with either Merlins or Pegasus but in practice only radials were fitted. The Mark IA was stressed to the Mark II 28,000 lb and had stronger undercarriage with larger wheels and Frazer-Nash turrets. Due to difficulties with performance of the Vickers turrets on the Mark I that left the Wellington with weaker than intended defences, production of Wellington Mk IB with Frazer Nash armament

17388-627: Was its insufficient lengthwise stiffness: when fitted with attachment for towing cargo gliders, its structure "gave" and stretched slightly. On 3 September 1939, the same day the United Kingdom declared war on Germany in response to the invasion of Poland, No. 3 Group Bomber Command based in East Anglia comprised six front line squadrons ( No. 9 , No. 37 , No. 38 , No. 99 , No. 115 and No. 149 Squadrons ) and two reserve squadrons ( No. 214 and No. 215 squadrons ), all equipped with

17526-680: Was launched. A total number of 11,461 aircraft is most often quoted. There is some question over several aircraft, the total may be a few either side of this figure. In combination, the Wellingtons and 846 Warwicks represent over 75 per cent of the total number of aircraft built by the Vickers-Armstrong company. There are two complete surviving Vickers Wellingtons preserved in the United Kingdom. Some other substantial parts also survive. Wellington IA serial number N2980

17664-566: Was one of two bombers named after Arthur Wellesley, 1st Duke of Wellington , the other being the Vickers Wellesley . A larger heavy bomber aircraft designed to Specification B.1/35 , the Vickers Warwick , was developed in parallel with the Wellington; the two aircraft shared around 85% of their structural components. Many elements of the Wellington were also re-used in a civil derivative, the Vickers VC.1 Viking . In October 1932,

17802-413: Was originally designated as a Type 271 , was assembled. The prototype could accommodate a payload of nine 250 lb or 500 lb bombs, and both nose and tail gun positions were fitted with hand-operated turrets with a gun in each; provision for a third retractable gun in a dorsal position was made. It had provision for a crew of four, along with a fifth position for special duties. On 5 June 1936,

17940-582: Was proposed for trials but since the Frazer-Nash turrets were already being accepted for the Mark IA, the Mark IB may not have been built or if built re-designated as Mark IA. Further development of various aspects of the aircraft, using knowledge learned was incorporated into the airframe at Weybridge by executive decision. Redesigned hydraulics and 24 volt electrical systems, along with a replacement of

18078-519: Was rarely achieved in practice. It also included various beacon homing modes, as well as an air-to-surface mode for detecting ships. This was modified to add a British strobe unit and variable pulse repetition frequency , becoming the Mark 21. The Mk. 21 was first used on the Meteor NF.12 and flew for the first time on the 21 April 1953, entering service in January 1954. Small improvements produced

18216-442: Was ready by August 1937 and fitted to Avro Anson K6260 at RAF Martlesham Heath . This unit demonstrated the ability to detect aircraft at the range of about 1 mile (1.6 km) in the air-to-air mode, but also demonstrated the ability to detect ships on the ocean at ranges up to 3 miles (4.8 km). This ability led to the split between AI and air-to-surface-vessel (ASV) radar systems, both of which would be widely used during

18354-524: Was received by Vickers; it had been placed so rapidly that the order occurred prior to the first meeting intended to decide the details of the production aircraft. In October 1937, an order was placed with Gloster Aircraft Company for production of 100 Wellington Mk Is to be followed by 100 Wellington Mk II aircraft with Rolls-Royce Merlin X . Another order was placed for 64 Wellingtons to be produced by Armstrong Whitworth Aircraft at Coventry With this flurry of order and production having been assured by

18492-452: Was recovered from the bottom of Loch Ness in September 1985 and restored in the late 1980s and 1990s. A new Wellington exhibition featuring N2980 was officially opened by Robin Holmes (who led the recovery team), Penelope Keith (as trustee of Brooklands Museum), Norman Parker (who worked for Vickers) and Ken Wallis (who flew Wellingtons operationally) on 15 June 2011, the 75th anniversary of

18630-590: Was shot down. On 18 December 1939, 24 Wellingtons of No. 9, No. 37 and No. 149 Squadrons participated in the Battle of the Heligoland Bight against the German fleet and naval bases in both the Schillig Roads and Wilhelmshaven. The Wellingtons were unable to drop their bombs as all vessels were in harbour, thus restrictions on endangering civilians prevented their engagement. Having been alerted by radar , Luftwaffe fighter aircraft intercepted

18768-423: Was suspended within the Lightning's circular nose air intake. The AI.23 was the world's first operational aircraft interception monopulse radar system. The monopulse method allows higher resolution and is far more resistant to common forms of jamming . AI.23 also included all of the features of earlier AI radars, and more. Among the highlights were an automatic lock-follow system which fed ranging information to

18906-450: Was the UK version of the SCR-720. This was originally promised for delivery in the summer of 1942, but ran into delays and only started arriving in December 1943. These were fit to the Mosquito to produce the NF.XVII and later versions. Conversions at operational units began in January 1944, and the Mk. X remained in service through the rest of the war. Compared to the Mk. VIII, the SCR-720 used

19044-498: Was to exist for the remainder of World War II . By the end of the war, over a dozen AI models had been experimented with, and at least five units widely used in service. This included several US-built models, especially for the Fleet Air Arm. The AI naming convention was used in the post-war era as well, but these generally dropped the "Mk." when written in short form and used numbers instead of Roman numerals . A good example

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