One of the most recent MR.2 airframes selected for re-build as an MRA.4, XV253/9118M had spent ten years in use as a ground instructional airframe at RAF Kinloss before being rolled onto An-124 RA-82045 of Volga-Dnepr there on October 21, 2001, for the journey to Woodford, where fuselage re-lifing was to be undertaken. In the early days of operation of both these aircraft this scene could not possibly have been imagined! As noted in the text, the task of re-lifing the fuselage was originally being undertaken by FRA/Serco at Bournemouth/Hurn, but eventually taken on by the original manufacturer at Woodford.
With the new wing in place, it is possible in this view to see the teardrop-shaped area ahead of the intakes which will be occupied by the ram air turbine (RAT). This is intended to provide contingency power generation for essential services in the event of electrical power failure.
The largest single new component of the Nimrod MRA.4 is the wing, the first example of which is seen here being prepared at Chadderton for mating with PA1. Even without the fuselage for reference it is possible to appreciate the greater depth of the centre section and the enlarged intake area for the new engines.
The most noticeable feature of the Nimrod MRA.4, when compared with the MR.2, is the increased intake area for the new engines, the larger span wing being virtually identical in plan view to that of the older aircraft. The turret for the electro-optical search and detection system under the forward fuselage is the other principal identifying feature of the new aircraft.
Former Nimrod pilots will probably view the cockpit of the MRA.4 with envy, the flight deck having been transformed into a working environment more typical of a civil airliner than a military combat aircraft. Much work had to go into providing an equivalent level of functionality with only two pilots on the MRA.4, after dispensing with the role of the flight engineer and the routine navigator of the MR.2. This has been achieved by the introduction of extensive systems automation and computer-based monitoring and alerting devices.
Artist’s impression of a Harpoon anti shipping missile being launched from the starboard outer underwing pylon.
The design of MRA.4 has been achieved using IBM and PTC computer aided design tools for fuselage and wing data respectively. The two design platforms have been successfully merged to provide a large user community, of varied engineering and IT disciplines, with a digital mock-up of the aircraft that enables detailed visualisation down to the tiniest rivet. This capability greatly enhances customary working practices at every level, such as illustrating maintenance documentation, as exemplified by this composite cutaway diagram.
Three-view drawing of BAE Systems Nimrod MRA.4