User:Hammersfan/BAE Systems Nimrod AEW3

The BAe Nimrod AEW3 was a planned airborne early warning aircraft intended as to provide airborne radar cover for the air defence of the United Kingdom by the Royal Air Force. The project was designed to use the existing Nimrod airframe, in use with the RAF as a maritime patrol aircraft, combined with a brand new radar system and avionics package developed by Marconi Avionics.

The Nimrod AEW project proved to be a hugely complex and expensive one for the British government, as a result of the difficulties of producing brand new radar and computer systems and integrating them successfully into the Nimrod airframe. Despite close to a decade's work, the project was eventually cancelled, with the RAF instead purchasing new build Boeing E-3 Sentry aircraft to fulfil the AEW requirement.

Development
In the mid 1960s, following the development of the Grumman E-2 Hawkeye carrier borne AEW aircraft, and its associated systems, the British government began looking around for a radar system that could be used to provide airborne early warning for the United Kingdom. At the time, the only recognised AEW aircraft in British service was the Fairey Gannet AEW3 aircraft used by the Fleet Air Arm on board Royal Navy aircraft carriers. these were fitted with the AN/APS-20 Radar, which had been developed during World War II and was rapidly becoming obsolete. To fulfil the planned requirements for a new AEW aircraft, the government had a number of factors to consider:


 * British industry wanted to develop a type of radar that would not operate effictively near propellors, meaning a jet aircraft would be needed.
 * The size of anntennas needed for the required scanning range, together with the fairly large mission crew, meant that a large aircraft was required.

Engineers eventually decided that the new Hawker Siddeley Nimrod maritime patrol aircraft met these requirements

Eventually, a decision was taken to procure an aircraft fitted with a pulse-doppler radar system, which then proceeded to a range of options:


 * 1) Purchase the AN/APS-125 pulse-doppler radar system and its associated avionics, as fitted to the E-2 Hawkeye, and fit them into the Nimrod.
 * 2) Purchase the AN/APS-125 radar and combine it with a British avionics package.
 * 3) Purchase the radome and anntenna from the E-2 and combine with a British radar transmitter, receiver and avionics package.
 * 4) Develop a wholly British radar system and avionics package using a Fore Aft Scanner System (FASS) rather than the E-2 radome.

While the fourth option was the most attractive as far as British industry was concerned, given that it would sustain thousands of British jobs, it was also far riskier than purchasing an "off the shelf" product that had already been proven. Nevertheless, the British government decided to proceed with the all-British development. Ironically, at around the same time, NATO was considering the purchase of a number of the new Boeing E-3 Sentry aircraft then beginning to enter service with the US Air Force.