be manually input by the operators. Upon entry into service, the Nimrod was hailed as possessing advanced electronic equipment such as onboard digital computers. The increased capability of these electronic systems allowed the RAF's fleet of 46 Nimrod aircraft to provide equal coverage to that of the larger fleet of retiring Avro Shackletons. The design philosophy of these computerised systems was that of a 'man-machine partnership'; while onboard computers performed much of the data sift and analysis processes, decisions and actions on the basis of that data remained in the operator's hands. To support the Nimrod's anticipated long lifespan, onboard computers were designed to be capable of integrating with various new components, systems, and sensors that could be added in future upgrades. After a mission, gathered information could be extracted for review purposes and for further analysis. Armaments and equipment The Nimrod featured a sizeable bomb bay in which, in addition to armaments such as torpedoes and missiles, could be housed a wide variety of specialist equipment for many purposes, such as up to 150 sonobuoys for ASW purposes or multiple air-deployed dinghies and droppable survival packs such as Lindholme Gear for SAR missions; additional fuel tanks and cargo could also be carried in the bomb bay during ferrying flights. Other armaments equippable in the bomb bay include mines, bombs, and nuclear depth charges; later munitions included the Sting Ray torpedo and Harpoon missile for increased capability. The Nimrod could also be fitted with two detachable pylons mounted underneath the wings to be used with missiles such as the Martel; two specialised pylons were later added to enable the equipping of Sidewinder missiles, used for self-defence purposes against hostile aircraft. A powerful remote-controlled searchlight was installed underneath the starboard wing for SAR operations. For reconnaissance missions, the aircraft was also equipped with a pair of downward-facing cameras suited to low and high-altitude photography. In later years a newer electro-optical camera system was installed for greater imaging quality. Various new ECMs and electronic support systems were retrofitted onto the Nimrod fleet in response to new challenges and to increase the type's defensive capabilities; additional equipment also provided more effective means of identification and communication. A number of modifications were introduced during the 1991 Gulf War; a small number of MR2s were fitted with improved Link 11 datalinks, new defensive ECM equipment including the first operational use of a towed radar decoy,