The AN-11 was France's first nuclear weapon, developed to arm the Force de frappe. The AN-11's development began in the late 1950s. An early version was used in France's first nuclear test, on 13 February 1960. The first AN-11 prototype was tested 1 May 1962, and it entered service in 1964. The AN-11 was a pure fission weapon, a plutonium implosion type. It weighed approximately 1,500 kg (3,306 lb). It was a free-fall bomb intended to be dropped from high-altitude bomber aircraft. The explosive yield was about 60 kTs.