The first four prototypes were designated the Canberra B.MK 1, and were intended for use with a radar-assisted bomb aiming system. A delay in this system led to the production of a day bomber prototype, the Canberra B.MK 2, and the first operational aircraft were delivered on May 25, 1951. The Canberra B.MK 2 differed in having a crew of three, the added member being the bombardier. The Canberra carried no defensive armament, placing its safety in speed and altitude. Indeed, for many years, the Canberra flew higher than any other aircraft, and in 1957 it captured a world altitude record of 70,000 feet. Well liked around the world, the US Air Force even built the Canberra as the Martin B-57 to replace its B-26 medium bombers. The B-57 saw combat over Vietnam beside other Canberras from Australia. In recent years, the Canberra has mostly been relegated to photographic reconnaissance (PR.Mk 9) and electronic warfare duties . A total of 1,352 Canberras were built before production ceased.
Today, seven privately owned Canberras can be found, several of which are actively airworthy. Three can be found in the UK, five in the USA, and one in South Africa. In addition, with the gradual and continued retirement of the type in the UK, Canberra fuselage sections have been auctioned off to collectors worldwide.