Nimrod MR1
In July 1964, Hawker Siddeley Aviation (formerly De Havilland) made a formal proposal to convert the Comet 4C turbo-jet powered airliner into a military aircraft (designated HS801). The HS801 became the first Nimrod, the Nimrod MR1. The type was designed for anti-submarine and antisurface unit warfare, surface reconnaissance and for search and rescue operations, i.e. the traditional roles of the MPA.9 The Nimrod MR1 was equipped with a wide range of radar and acoustic equipment and had the ability to drop sonobuoys, to detect and track submarines, as well as carrying weapons such as torpedoes and Search and Rescue (SAR) equipment.
The first flight of a prototype Nimrod MR1 was on 23 May 1967. The first flight of a new-build production Nimrod MR1 was on 28 June 1968. As stated above, the RAF took delivery of its first Nimrod MR1 on 2 October 1969, at RAF St. Mawgan when it was handed to No. 236 Operational Conversion Unit. This was XV230.
The Nimrod MR1 enabled the newly formed No. 18 (Maritime) Group of Strike Command to fulfil its task: "The undertaking of surveillance operations to maintain a flow of information about the movement of potentially hostile surface vessels and submarines over vast ocean areas." The 43 Nimrod MR1s were operated primarily from RAF Kinloss, Morayshire, and RAF St. Mawgan, Cornwall. No. 203 Squadron at Luqa, Malta, were also equipped with Nimrods but, following the 1974 Defence Review, this Squadron was disbanded and its Nimrod MR1s flown back to the UK and placed in storage.
The Nimrod was originally designed as a successor to the Avro Shackleton Maritime Patrol Aircraft (MPA) in the maritime reconnaissance role.24 The aircraft was specifically designed and built for maritime reconnaissance. Since 1969, it fulfilled a largely maritime role, until its more recent involvement overland in Afghanistan and Iraq. The ability of the Nimrod to transit at high speed and then 'loiter' at a lower speed for long periods made it ideally suited to the task of maritime reconnaissance.
The terms MPA and Maritime Reconnaissance are effectively interchangeable and encompass a number of key subsidiary roles. The first is that of Anti-Submarine Warfare (ASW). The Nimrod is equipped with a range of sensors, including sonobuoys and radar to detect submarines, and torpedoes to attack them if required. The aircraft can also undertake Anti Surface-Unit Warfare (ASUW), using its sensors to detect, identify and track surface vessels; and, if required, the Nimrod can also use the same sensors to guide other aircraft to attack these surface vessels. While carrying out both roles, the Nimrod will collect and convey intelligence information to its operating authority. The final core role of the MPA is that of Search and Rescue (SAR). Nimrods can utilise all of their sensors to undertake long range SAR missions and are capable of dropping survival equipment and of guiding helicopters to specific locations to rescue survivors.
The principal reason for the conversion of the Nimrod from MR1 to MR2 was to upgrade the aircraft's sensor systems. The heat generated by the new electronic equipment on board required additional air supplies for cooling. For this purpose, a Supplementary Conditioning Pack (SCP) was fitted to the Nimrod MR2 in the rear of the aircraft. The SCP was supplied with engine bleed-air from a branch taken off from the Cross-Feed duct. This air was ducted through a pressure regulating valve in the bomb bay and then ducted rearwards outside the bomb bay. At the point where the SCP leaves the bomb bay, it is routed through the lower part of the starboard No. 7 Tank Dry Bay. With engines at high power at low altitude, the temperature of the air in the SCP duct could be in the region of 470ºC. Thus, this addition to the already existing Cross-Feed duct placed a potential source of ignition in the aircraft, the significance of which was not recognised until over 25 years later, with the investigation into the loss of XV230.
|
NEWSLETTER
|
| Join the GlobalSecurity.org mailing list |
|
|
|
