BAE Systems Nimrod MRA4

Nimrod MRA4
Nimrod MRA4 during a test flight
Role	Maritime patrol aircraft Type of aircraft
National origin	United Kingdom
Manufacturer	BAE Systems
First flight	26 August 2004[1]
Status	Cancelled
Number built	3 development plus 2 production[2]
Developed from	Hawker Siddeley Nimrod MR2

The BAE Systems Nimrod MRA4 was a planned maritime patrol and attack aircraft intended to replace the Hawker Siddeley Nimrod MR2. The rebuilt aircraft would have extended the operating life of the Nimrod fleet by several decades and significantly improved the aircraft by installing more efficient Rolls-Royce BR700 turbofan jet engines to almost double the flight range. The conversion of the flight deck to a digital glass cockpit would have simplified control operations and reduced crew requirements. New detection systems were to be installed, as well as additional weapons for anti-submarine warfare.

However, the project was subject to significant delays due to cost overruns and contract re-negotiations. This was partly due to difficulties combining refurbished Nimrod MR2 fuselages, which had not been built to a common standard, with newly built wings. The numbers of aircraft to be procured fell from twenty-one to nine over a course of years, while costs continued to climb.

The MRA4 was ultimately cancelled in 2010 as a result of the Strategic Defence and Security Review (SDSR), at which point it was £789 million over-budget and over nine years late. No direct replacement was under development at that stage, with the roles intended for the MRA4 filled by existing assets such as the Type 23 Frigate and the Merlin helicopter. However the UK announced its intention to order nine P-8 Poseidon ASW aircraft as part of the 2015 SDSR at a cost of £3 billion; these aircraft were delivered between October 2019 and January 2022 and operate from RAF Lossiemouth in Scotland.