Blackburn's first attempt to sell the Buccaneer to the Royal Air Force (RAF) occurred in 1957–58, in response to the Air Ministry Operational Requirement OR.339, for a replacement for the RAF's English Electric Canberra light bombers, with supersonic speed, and a 1000 nautical miles combat radius; asking for an all-weather aircraft that could deliver nuclear weapons over a long range, operate at high level at Mach 2+ or low level at Mach 1.2, with STOL performance.