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The English Electric Canberra B.1 Prototype – as it should have been designed.

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The English Electric Canberra B.1 Prototype – as it should have been designed.

 

During the Second World War, a desperate demand for bomber aircraft led to many aircraft being produced by secondary manufacturers via licence manufacturing arrangements. The English Electric company mass-produced thousands of piston-engined bombers, such as the Handley Page Hampden and Handley Page Halifax, in this manner and the firm thus became a well-established British aircraft manufacturer despite having little internal design experience. Sir George Nelson, the chairman of English Electric, decided that the company would seek to remain in the business and produce its own designs. In November 1943, the company was invited to participate in discussions over a prospective bomber which would take advantage of the newly developed jet propulsion technology.

 

In 1944, Westland Aircraft's technical director and chief designer W. E. W. Petter had prepared a design study for a twin-engined fighter bomber, the P.1056, based on two fuselage-mounted Metrovick F.2/4 "Beryl" engines. The design used a relatively conventional aerodynamic design, Petter having determined that the necessary performance could be attained without adopting swept wings or a swept tail. The authorities doubted its suitability for operations from unprepared fields and at low altitude but could see its potential as a bomber design; numerous manufacturers refused to take on the design. Petter left Westland to join the English Electric company in December 1944, where he was appointed by Nelson to form a design team and encouraged to develop his design. In 1945, English Electric formalised its own in-house aircraft design team to pursue this design.

 

The Canberra had its formal origins in a 1944 requirement issued by the Air Ministry for a successor to the de Havilland Mosquito. This requirement, the initial revision being E.3/45, sought a high altitude, high-speed bomber which was to be equipped with no defensive armament. According to aviation historians Bull Gunston and Peter Gilchrist, Air Ministry officials are alleged to have had difficulty defining what they sought for the proposed type, which led to several revisions of the requirement. Further specification refinements were issued, including B.3/45 and B.5/47, issued further details such as a three-man crew and other features such as a visual bombing capability. Several British aircraft manufacturers submitted proposals to meet the requirement, including English Electric. The firm was among those companies to be short-listed to proceed with development studies.

 

By June 1945, the aircraft that was to become the Canberra bore many similarities to the eventual design, despite the placement of a single, centrally mounted turbojet engine; Petter had held discussions with Rolls-Royce Ltd on the topic of the development of a scaled-up derivative of the Nene engine. In late 1945, the design was modified further with a pair of engines being adopted instead, to be set in the wing roots; this change was made principally due to centre of gravity issues imposed by the position and weight of a heavy bombload and centrally-mounted single engine. The new engine position decreased the aircraft's weight by 13 per cent and improved the aircraft's centre of gravity, as well as improved accessibility to the engines and related accessories.

 

During the early design stages, the aircraft had grown from being roughly the same size as the Mosquito to being around double its weight. Although jet-powered, the Canberra design philosophy was very much in the Mosquito mould, providing room for a substantial bomb load, fitting two of the most powerful engines available, and wrapping it in the most compact and aerodynamic package possible. Rather than devote space and weight to defensive armament which historically could not overcome fighter aircraft, the Canberra was designed to fly fast and high enough to avoid air-to-air combat entirely. On 7 January 1946, the Ministry of Supply placed a contract for the development and production of four English Electric A.1 aircraft. It continued to be known as the English Electric A.1 until it was given the name Canberra after the capital of Australia in January 1950 by Sir George Nelson, chairman of English Electric, as Australia had become the aircraft's first export customer.


Prototypes and first flights

 

The Air Ministry specification B.3/45 had requested the production of four prototypes. On 9 January 1946, English Electric received a contract to produce four prototypes, which received the Society of British Aerospace Companies (SBAC) designation A.1; work commenced on the construction of these prototype aircraft in that same year, which were all built on production jigs. However, progress was slow due to several factors, such as the protracted development of the Avon engine that powered the type; in October 1947, in response to Rolls-Royce's difficulties, English Electric elected to have the second prototype modified to use the existing Nene engine in place of the Avon. The implementation of post-war military cutbacks also served to slow development.

 

A further external issue that affected development was the failure of the Telecommunications Research Establishment to produce the intended radar bombing system for the aircraft in a timely fashion; this required a redesign in 1947, changing the aircraft's nose to accommodate a glazed tip for visual bombing by a bomb aimer, which in turn required the cockpit to be restructured to facilitate the ejection system of the additional crewmember. In 1948, the design team relocated to Warton Aerodrome, Lancashire; establishing a flight test organisation and assembly facilities there.

 

Ultimately, the first of these prototypes, VN789 did not conduct its maiden flight until 13 May 1949. Piloted by Roland Beamont, the aircraft is claimed to have handled well with the exception of a rudder overbalance issue encountered. This initial flight was flown with the intended Avon engines, the decision to perform the type's first flight with the Avon-equipped first prototype or the Nene equipped second prototype, VN828, was not made until weeks beforehand. On 9 November 1949, the second prototype, VN828, the first to be equipped with the Nene engine, performed its first flight; the third and fourth followed within the following eight weeks.

 

Flight testing of the prototypes proved to be vice-free and required only a few modifications to be made. The changes included the installation of a glazed nose to accommodate a bomb-aimer, due to the advanced H2S Mk9 bombing radar not being ready for production, the turbojet engines that powered the type were replaced by the more powerful Rolls-Royce Avon R.A.3s, and distinctive teardrop-shaped fuel tanks were fitted under the wingtips. Refinements were also quickly made following early flight testing to the rudder and elevator to reduce instances of buffeting, after which it is claimed that the Canberra handled much like a fighter, proving to be atypically manoeuvrable for a bomber.

 

The project had found considerable support from the government in the late 1940s. In March 1949, in advance of the maiden flight of the first prototype, English Electric received an instruction to proceed for production. By the time the first prototype had flown, the Air Ministry had already placed orders for 132 production aircraft in bomber, reconnaissance, and training variants. On 21 April 1950, the first production-standard aircraft, designated as the Canberra B2, conducted its maiden flight, piloted by Beamont. Proving to be fairly free of problems, this first flight was almost immediately followed by the mainstream manufacturing of production Canberras. In May 1951, the Canberra entered RAF squadron service, No. 101 Squadron being the first to receive the type. In a testament to the aircraft's benign handling characteristics, the transition programme for the Canberra consisted of only twenty hours in the Gloster Meteor and three hours in a dual-control Canberra trainer.

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The Model

 

The model is a converted, venerable Airfix Canberra B.20/B(I).6 kit, with all it's associated problems of it's nose contours being incorrect.   I had a correcting Airmodel nose but decided not to use it.  I also used the engines from a Hobbycraft CF-100 kit.   First I cut the engines from the Canberra wings and then replaced them with plasticard and putty, contouring it to the correct profile.   Then I attached the engines to the Canberra fuselage and used a great deal of putty to create and smooth over the joins.  Then it was the turn of the tail planes.  Realising that they would be too low, I raised them up the tail and then added the tail on top of a piece of thick plasticard.  A considerable amount of putty to smooth it all out. I then ended up adding over 90 grams of nose weight and still it sat on it's tail!  Running out of room to put more noseweight in, I called it quits.  In the end, I used a tail support, reasoning that in real life Canberras could, if unfueled and uncrewed, be tail sitters.   I then had to figure what colour to paint the beast.  I asked online and many were the various shades of blue which were recommended.  I ended up using Vallejo Azure Blue and a hairy stick.  In order to represent the H2S nose I just use the clear nose cone, painted over.  After several coats of Future to create the gloss effect I was looking for, it was then a matter of raiding the Decals store to find the correct roundels and titles.

 

Remember, this is how the English Electric Canberra should have been designed.  The engine placement on the Canberra was always problematic.  They were set too far apart and caused considerable yaw problems if not correctly monitored if one engine failed.  So, far more sensible would be to place them on either side of the fuselage which is what I did, using the CF-100 engine pods.   In the end, the model turned out better than I thought it would.  Bon Appétit!

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An interesting idea: I suspect that there were specific reasons for placing them where they were.  Not that I can bring any to mind offhand, unless the lack of experience with jet engines suggested ensuring the intakes were in clear flow, away from disturbing influences such as the fuselage.   I suspect that a simpler planform might have been chosen for the wing, although maybe not.

 

It was said that more Canberras had been lost (and crew killed) practicing single-engined failures than ever occurred for real.

 

I assume that you are aware that Gloster's chief test pilot G. A. Waterton advised precisely this configuration to the Gloster Board for the Meteor.  This would of course have been much more difficult with the Meteor, a design already fully worked up and in production - indeed it would mean a new aircraft.  The Meteor was initially a conservative design and was already approaching obsolescence, so its easy to see why Gloster rejected any such idea - although the following Javelin did feature engines nearer the centre-line.

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I dunno if that's how it should have been, but it certainly looks the business.

Even Statler and Waldorf would approve.  :lol:

 

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One of the factors affecting the Canberra's engine placement may well have been design inertia -- that is, a bad case of  "this is how it's always been done". Twin-engined bombers had always had their engines out on the wings -- they'd had to because of the props, the fore-and-aft engine concept never really having caught on. The Canberra, however. was something new: a twin-engined bomber without propellers. This meant that the engines could have been located much closer to the centreline as you have them, but I suspect the draughtsmen would automatically think of the outboard layout through force of habit. This is just speculation on my part, but history is full of similar instances.

 

The Meteor is a slightly different kettle of fish because of its engines. The original Derwent engines, like Whittle's first flight-worthy designs, had centrifugal compressors, which meant that they were fat -- certainly much more so than the axial-flow engines of the Canberra. The Goblin was much the same, which is one reason why the Vampire looked the way it did. The fat (or broad) centrifugal engines couldn't be placed as close in as the narrower axial-flow types -- well,, they could, but the fuselage would have ended up distinctly tubby, which would have been a problem performance-wise, and would have meant a serious re-design of the whole aircraft. Gloster could have done it, but the time and cost involved would have been significant, to say the least, so the management would not have been keen to chuck out everything that had already done.

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Oh, I agree there were reasons, quite valid ones, at the time why they designed the Canberra the way they did.  One was that the engines were slimmer and lighter and the wanted the fuselage for the maximum bombload with the engines out of the way.  The problem was they'd never really experiences a powerful, jet engine pushing a plane sideways because it was situated out on the wing, so asynchronous  thrust was discovered.  This was just an exercise in "what might have been..."

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