English Electric Canberra - Design

Design

The Canberra is mostly constructed of metal, only the forward portion of the tail-fin is made from wood. The wing is of single-spar construction that passes through the aircraft's fuselage; the Wingspan and total length of the Canberra were almost identical at just under 20 metres. Outboard of the engine nacelles, the wing has a leading-edge sweep of 4° and trailing-edge sweep of -14°. Controls are conventional with ailerons, four-section flaps, and airbrakes on top and bottom surfaces of the wings.

The fuselage of the Canberra is of semi-monocoque construction with a pressurised nose compartment. Due to the use of a new alloy, DTD683, the undercarriages of the Canberra suffered from stress corrosion, which caused them to decay within a few years. The extreme hazard posed of undercarriages collapsing during landings, especially if the aircraft were carrying nuclear weapons, led the RAF to institute regular inspections, at first using radiography before moving to more effective and reliable ultrasound technology.

Thrust was provided by a pair of 30 kN axial flow Rolls-Royce Avon turbojets. The manufacturer specified that Coffman engine starters should be used to start the engine. An improvised method of starting the engine using compressed air was heavily discouraged by Rolls-Royce, but some operators successfully operated the Canberra's engines in such a manner, the benefit being significant cost savings over cartridges. The aircraft's maximum take-off weight was a little under 25 tonnes.

"The value of the Canberra experience cannot be over-estimated. It is the only modern tactical strike and reconnaissance aircraft in service with the RAF and many other Air Forces. More Canberra aircraft are in service with foreign countries than the Viscount, which holds the record for British civil aircraft. This is due to the flexibility of the Canberra in its operational roles and performance..."

It was designed for a crew of two under a fighter-style canopy, but delays in the development of the intended automatic radar bombsight resulted in the addition of a bomb aimer's position in the nose. Each crew member has a Martin-Baker ejection seat except in the B(I)8 and its export versions where the navigator makes use of an escape hatch and parachute.

The Canberra could deploy many conventional weapons, typical weapons used were 250-pound, 500-pound, and 1000-pound bombs, the total bomb load could weigh up to 10,000 pounds (4.5 t). Two bomb-bays are housed within the fuselage, these are normally enclosed by conventional clam-shell doors; this was substituted for a rotating door on the Martin-built B-57 Canberras. Additional stores up to a total of 2,000 pounds (0.91 t) could be carried upon underwing pylons.

Operators such as Rhodesia developed their own munitions such as anti-personnel bomblets, the Alpha bomb, and adapted these for use by their Canberra fleets. Anti-personnel flechette bombs were tested successfully from the Canberra by Rhodesia, but not used operationally due to international agreements.

In part due to its range limitation of just 2,000 miles (3,200 km), and its inability to carry the early, bulky nuclear bombs, the Canberra acted as more of a tactical bomber than a strategic one. Many Canberras that were stationed at remote overseas locations did not undertake modifications to become nuclear-capable until as late as 1957.