It was an extensive modification of the de Havilland Comet, the world's first operational jet airliner. It was originally designed by de Havilland's successor firm, Hawker Siddeley; further development and maintenance work was undertaken by Hawker Siddeley's own successor companies, British Aerospace and BAE Systems, respectively. Designed in response to a requirement issued by the Royal Air Force (RAF) to replace its fleet of ageing Avro Shackletons, the Nimrod MR1/MR2s were primarily fixed-wing aerial platforms for anti-submarine warfare (ASW) operations; secondary roles included maritime surveillance and anti-surface warfare. It served from the early 1970s until March 2010. Number built: 49 (+2 prototypes). The Nimrod was the first jet-powered maritime patrol aircraft (MPA) to enter service, being powered by the Rolls-Royce Spey turbofan engine. Aircraft in this role had been commonly propelled by piston or turboprop powerplants instead to maximise fuel economy and enable maximum patrol time on station; advantages of the Nimrod's turbofan engines included greater speed and altitude capabilities, and it was more capable of evading detection by submarines, as propeller-driven aircraft are more detectable underwater by standard acoustic sensors. The Nimrods had a flight endurance of ten hours without aerial refuelling; the MR2s were later fitted to receive mid-air refuelling in response to demands of the Falklands War. For details of the development, design, operational history and variants, click here.
