The Canberra had one of the longest careers of any post war military aircraft, the first example flying in 1949, the RAF will still be using the photo reconnaisence version for some time yet, the aeroplane in this case being much older than the majority of its pilots. Conceived as a light bomber relying on speed and altitude for protection in the tradition of the De Haviland Mosquito it was an immediate success, and like the Mosquito it proved remarkably amenable to modification to other roles. The Canberra was designed by W.E.W. Petter to meet Air Ministry specification B3/45 which called for an aircraft capable of carrying the same bomb load as the Mosquito, (4000 lb's), a range of 800 miles with a ceiling in excess of 30,000 ft. The resulting aircraft was of simple, yet innovative design with it's three crew members accomodated in a pressure cabin located in the extreme nose. Almost all the aircraft systems were of WW2 technology with the exception of a tail warning radar known as 'Orange Putter'. Infact compared to the American B47 six jet bomber which first flew two years earlier, the Canberra appeared overly conservative. Yet the Americans were to build 400 examples of the Canberra themselves, many of which were to remain in service for twenty five years, long after the last examples of the B47 were discarded. The secret of the Canberra's success was a combination of low wing loading and lashings of excess power which gave the Canberra astonishing manouverability at low level and an altitude performance which no other contemporary aircraft could match. In addition to which the airframe was extremely rugged and low maintainence. The Canberra T4 was the two seat trainer version of the Canberra.