English Electric Canberra

The English Electric Canberra is a British first-generation, jet-powered medium bomber. It was developed by English Electric during the mid- to late 1940s in response to a 1944 Air Ministry requirement for a successor to the wartime de Havilland Mosquito fast bomber. Among the performance requirements for the type was an outstanding high-altitude bombing capability and high speed. These were partly accomplished by making use of newly developed jet-propulsion technology. When the Canberra was introduced to service with the Royal Air Force (RAF), the type's first operator, in May 1951, it became the service's first jet-powered bomber.

In February 1951, a Canberra set a world distance record when it became the first jet aircraft to make a nonstop transatlantic flight. Throughout most of the 1950s, the Canberra could fly at a higher altitude than any other aircraft in the world, and in 1957, a Canberra established a world altitude record of 70,310 feet (21,430 m). Due to its ability to evade the early jet interceptor aircraft, and its significant performance advancement over contemporary piston-engined bombers, the Canberra became a popular aircraft on the export market, being procured for service in the air forces of many nations both inside and outside of the Commonwealth of Nations. The type was also licence-produced in Australia by Government Aircraft Factories (GAF) and in the US by Martin as the B-57 Canberra. The latter produced both the slightly modified B-57A Canberra and the significantly updated B-57B.

In addition to being a tactical nuclear strike aircraft, the Canberra proved to be highly adaptable, serving in varied roles such as tactical bombing and photographic and electronic reconnaissance. Canberras served throughout the Cold War, in the Suez Crisis, Vietnam War, Falklands War, Indo-Pakistani wars, and numerous African conflicts. In several wars, each of the opposing sides had Canberras in its air force.

The Canberra served for more than 50 years with some operators. In June 2006, the RAF retired the last three of its Canberras 57 years after its first flight. Three of the Martin B-57 variant remain in service, performing meteorological and re-entry tracking work for NASA, as well as providing electronic communication (Battlefield Airborne Communications Node) testing for deployment to Afghanistan.^{[needs update]}

During the Second World War, a desperate demand for bomber aircraft led to many aircraft being produced by secondary manufacturers via licensed manufacturing arrangements. The English Electric company thus mass-produced thousands of piston-engined bombers, such as the Handley Page Hampden and Handley Page Halifax, and the firm 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 that 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 aircraft 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 Bill 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, 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, initially to be set in the wing roots and later to be mounted in a midwing position; 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% and improved the aircraft's centre of gravity, as well as improved accessibility to the engines and related accessories; its downsides were slight thrust loss from the longer jet pipes and greater yaw during engine-out instances.