English Electric Canberra
Canberra : Early Development
Authors Introduction: This chapter is part of a book that I am attempting to write along with Jagan Pillarisetti, on the English Electric Canberra in IAF service. We have a blog http://iafcanberra.wordpress.com, please visit there and leave comments by clicking on the "Comment" link near the title of any blog entry. The author wishes to thank Wg Cdr Vineet Bhalla (Retd) and Wg Cdr Joseph Thomas (Retd) for their help and advice during the preparation of this article.
The English Electric/British Aerospace Canberra first flew on Friday the 13th of May 1949. Yes, that is not a typo - it first flew in 1949 (and they did do the first flight on Friday the Thirteenth)! The Canberra is still operational today with the IAF with 106 Strategic Reconnaissance Squadron (SRS) of the Indian Air Force. This represents a period of 57 years as of 2006! Current plans call for the Indian Air Force to operate their Canberras until May 2007, at which time the type will be 58 years old. To put this longevity in perspective, the World War I Sopwith Camel would need to be operational till 1975 to match this record!
The Indian Air Force (IAF) had by far the largest fleet of export Canberras purchasing over a 100 aircraft. Only the RAF and USAF exceeded the IAF in numbers of Canberras operated. The IAF also had the distinction of operating the Canberra in anger more often than any other air force. The IAF operates a proliferation of Canberra types, in multiple roles. In this article an attempt is made to describe those types, their technical and operational characteristics and their use in the Indian Air Force.
Early Canberra Development
Design and Development
The English Electric Canberra was the brainchild of the brilliant designer W.E.W Teddy Petter. Petter was the son of the Managing Director of Westland Aircraft and was initially Chief Designer there. The Westland Wapiti, the first aircraft type operated by the IAF, came from Westlands stable. Petter designed the Westland Lysander, which 1 Squadron IAF took to war in Burma in 1942 during World War II. Petter seems to have been a favorite designer of the IAF, the IAF operated a representative type for each of the aircraft firms that he was Chief Designer of the Westland Lysander, the English Electric Canberra and the Folland Gnat! Petter also designed the first and only wholly British Mach 2 fighter, the English Electric Lightning.
The English Electric Company was a locomotive company, and had earned its spurs as a shadow factory operator, mass producing Handley Page Hampden and Halifax bombers during World War II. In fact the companys excellent quality control and prolific output (it produced more Halifax bombers than Handley Page itself) resulted in it being short-listed to build a jet bomber for the RAF in 1944.
English Electric had no design team, so it hired Petter away from Westland. Petter had a reputation for being temperamental and was not getting along with the management at Westland. He had a great opportunity to build a design team from scratch and he made the most of it! He started work on Air Ministry specification B3/45, which called for high speed, high altitude, unarmed bomber in the tradition of the de Havilland Mosquito.
The aircraft that emerged from the drawing board was designed for a cruising speed of 518 mph at 40000 ft and a service ceiling of 50000 ft a bar that the Canberra exceeded handsomely. Petter deliberately selected broad chord, low aspect ratio and relatively lightly loaded un-swept wings and decided not to use wing sweep. This gave the Canberra its exceptional handling characteristics at high altitudes and maneuverability at low altitude. The bomber was to be powered by two AJ 65 (Avon) engines, housed in nacelles at about one quarter span and buried in the wings. The horizontal tail was tapered but un-swept. The main undercarriage was inward retracting and mounted immediately inboard of the nacelles. The aircraft had a twin nosewheel. The stressed skin semi-monocoque fuselage accommodated the crew in a pressurized nose section, the design bomb load of 6000 lb and all the fuel. The pilot sat under a one-piece jettisonable canopy and his crew behind him in the fuselage. Every crew member was equipped with an ejection seat. The controls were all manual with spring tabs, being electrically operated for trimming purposes only.
Such was Petters foresight in design that the basic configuration of the airplane did not change in 20 years of production. Crew accommodation configuration changes, wing fuel, powered controls, extra wing surface and more powerful engines were all added but the aircraft remained recognizably like the prototype Canberra throughout its life. Even the configuration changes were facilitated by the fact that Petter had designed the Canberra to be of modular construction with five independent primary structures which could be mixed and matched to meet any role type. These five structures were front fuselage, centre fuselage, rear fuselage, mainplane non-anti-icing, mainplane anti-icing with integral fuel tanks.
The Early operational marks
The first mark in operational service was the Canberra B Mk 2 the initial order specifying 5 different marks of the Canberra tactical bomber, blind bomber, target market bomber, long range PR aircraft and trainer. There were only four B Mk 1s and they were built with solid noses. The radar for the blind bomber was not forthcoming so a visual bombing version with a Plexiglas nose with accommodation for three crew members (pilot, navigator and bomb aimer), was built as the B. Mk 2. There was no armament other than the bomb load, and the bomber was to rely on its high speed of 0.8 Mach at 45000 ft to evade any fighters attempting to intercept it. There was a lot of criticism of this change from the radar bombing role to a visual daylight bomber critics charging that the Canberra was obsolete for that role from the beginning. The operational characteristics of the Canberra however made it adept at performing multiple roles, and that was responsible for its success operationally rather than any single characteristic. The early operational marks the B Mk 2, P.R. Mk 3 and the T.4 all shared primary characteristics. They were powered by the Rolls Royce Avon Mk 1/RA 3 engine of 6500 lb thrust each. They carried fuel in the fuselage and jettisonable wingtip tanks but did not have any fuel in the wings. Total fuel capacity was of the order of 1,874 gallons with wingtip tanks fitted. The B.2 was a day bomber and could carry 10000 lbs of bombs. The Photo reconnaissance PR.3 had an extended fuselage and could carry up to 7 cameras for both day and night photography and had an extra fuel tank in the fuselage giving it a fuel capacity of 2417 gallons. The T.4, the dual pilot trainer version, will be described with the other IAF specific marks. By the time the Indian Air Force expressed interest in the Canberra, a new generation of Canberras had emerged.
Canberras for the Indian Air Force
The Indian Air Force first expressed its interest in the Canberra officially during a visit of the Secretary of Defence in June 1956. A few Indian Air Force pilots had already flown the Canberra by then including the Indian Air Attache to the UK Gp Capt (later Air Chief Marshal and Chief of Air Staff) Moolgavkar. He had flown the Canberra as early as 1954 as part of an evaluation team led by Air Commodore P C Lal. Most ETPS (Empire Test Pilots School) courses by then had one or two Indian test pilots under training. Gp Capt Kapil Bhargava, then a Flt Lt and a trainee at ETPS, flew a Canberra T.4 trainer several times as part of his training (see inset).
English Electric must have felt very confident that they would receive an order; they started work on the IAF Canberras before the order was finally placed in early 1957. The order was for 80 aircraft and was by far the largest export order placed for the Canberra. The amount was £20 million. Some of this money was offset by the debt that the UK government owed the Indian government for services rendered during WWII and reparations. Even so it seems like the Indian negotiators drove a good bargain £20 million being approximately $250 million in todays currency. Seems like a small amount compared to what India is paying for the BAe Hawk today (approximately $1.7 billion for 66 aircraft!).
The orders were for 65 English Electric Canberra B(I)58 aircraft, 8 PR.57 aircraft and 7 T.4 aircraft.
The B(I)58 was equivalent to the RAFs B(I)8 interdictor bomber. The PR.57 was the equivalent of the RAFs PR.7 photo reconnaissance version. The T.4 was the same mark as the RAF trainer version. It is erroneously reported that the IAF trainers were T.54s but there was no such designation given by either the factory or the IAF. The Indian Air Force never referred to the trainers by any other designation they were always referred to as T.4s. This was in contrast to the B(I)58 and the PR.57 those marks were referred to with their full IAF designation.
Being master negotiators, the Indian procurement team had been very wise in prescribing equipment fit they had included a number of modifications that the RAF pilots wished they had in their equivalent marks! These included a radio altimeter, improved navigation kit and an autopilot.
All the Canberras were to be new build aircraft, though 24 were diverted from an RAF order for B(I)8s. One of the these diverted aircraft, a B(I)8 IF-906 (ex-WT388, which is still flying as an Electronic Warfare aircraft with 106 SRS) was modified by Bolton Paul Aircraft to act as the trials installation aircraft for the IAFs additional equipment. Deliveries of the aircraft started in April 1957.
The IAF marks will be described in detail, but first a small detour into the evolution of the Canberra from the B.2 and PR.3 described above.
The second generation Canberras
In 1951 the RAF issued a new specification B22/48 for a target marker Canberra with improved radar and improved low level performance. English Electric responded with the Canberra B Mk 5. This introduced major changes to the Canberra the biggest of which was the introduction of the Avon Mk 109 (RA.7) engines. Each of these engines gave 7400 lbs of thrust which was 900 lb more on each side than the Avon RA.3 fitted on the B. Mk 2, PR. Mk 3 and the T.4. Another major structural change was the addition of integral wing tanks which gave a total of 900 gallons additional fuel. Dunlop Maxaret anti-skid braking units were introduced. The changes increased range to 3,400 miles and the maximum speed increased by 10 mph. The Avon RA.7 had anti-icing protection and was more resistant to compressor stalls and surging. The radar desired for the Canberra B Mk 5 did not materialize and this resulted in the visual bombing Canberra B MK 6 being produced instead. The Canberra B Mk 6 was a B MK 2 bomber incorporating the improvements introduced by the B Mk 5. The B Mk 6 was essentially what all the IAF Canberra marks (except the T.4) were based on.
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