Nimrod MRA4
Replacement Maritime Patrol Aircraft (RMPA)

The RAF needed a replacement for the Nimrod MR Mk 2 aircraft, its ground support systems and synthetic training equipment. Wartime roles comprise Anti-Submarine Warfare (ASW), Anti-Surface Warfare (ASUW) and Search and Rescue (SAR). The Requirement was endorsed and an initial data gathering phase authorised in November 1992. Procurement responsibility was then passed to the Procurement Executive (now DPA). A Request for Information (RFI) was issued to 17 potential prime contractors who had registered an interest. Analysis of the responses allowed a competitive procurement strategy to be pursued with a high probability of success. A competitive tendering phase was initiated in January 1995. Four companies submitted proposals.

In 1993, Air Staff Requirement (ASR) 420 called for a replacement for the MR2. The MR2 fleet was to be replaced by Nimrod 2000 in a refurbishment program managed by British Aerospace. The Replacement Maritime Patrol Aircraft (RMPA) competition was won by BAe with their Nimrod 2000 proposal. The RAF had formerly declared that the aircraft will be known as Nimrod Maritime Reconnaissance & Attack (MRA) Mark 4. On 25 July 1996, the contract was awarded to BAE Systems who proposed using the existing MR2 airframes, fitting larger wings (127 feet), Rolls-Royce BMW BR.710 engines, new radar and sensor systems and a new tactical computer system.

As the prime contractor, British Aerospace would supply a complete package of 21 mission-equipped Nimrod 2000 aircraft, together with a training system and initial logistic support. The fixed-price contract for the delivery of 21 Nimrod MRA4 aircraft training systems and initial support was signed with BAe in December 1996. Existing MR Mk 2 aircraft fuselage and empennage structure would be re-lifed and reassembled, with redesigned wings and current technology BR710 turbofan engines. The refurbished aircraft, to be delivered between 2001 and 2006, will have new wings, BMW/Rolls Royce fuel efficient engines, modern control systems, 'glass' cockpit instrumentation, and a comprehensive suite of the latest sensor, computer and communications equipment. In February 1997, the first three stripped-down Nimrod fuselages were delivered to FR Aviation in Bournemouth, who were contracted to refurbish them.

Although some of the systems are retained, the majority of the air vehicle systems are replaced, including the flight deck, which will accommodate a reduced cockpit crew complement of two, facilitated by automated flight systems using modified Airbus A340 technology. The mission system, which is the heart of the weapon system, is entirely new. The cabin interior is totally refitted to suit the new mission systems layout. Again, the mission crew numbers have reduced from ten to eight.

This is therefore essentially a new aircraft, not a refurbished one, comprising 95% new design and a new fully integrated mission system. It is undoubtedly the most complex aircraft built by BAE SYSTEMS, with the most challenging flight test programme in terms of time scale. In early 1998 the aircraft was renamed from Nimrod 2000 to Nimrod Maritime Reconnaissance and Attack Mk4 - Nimrod MRA4. Technical and resourcing difficulties encountered during 1998 led to a re-baselining of the program which delayed the introduction of the first aircraft into service. The delay enabled certain enhancements in capability to be included.

Under the Smart Procurement Initiative, the Nimrod MRA4 was identified as one of the pilot Integrated Project Teams (IPTs) in November 1998, led by Air Commodore Barry Thornton. Although the project was established around an integrated team concept from the outset, both at Abbey Wood and in industry, the latest initiative enabled the Nimrod Integrated Project Team to re-focus and embrace other personnel who work full time on Nimrod MRA4 from other areas which were previously outside the IPT.

The Nimrod MRA4 contract was let with BAE SYSTEMS in December 1996 with an In-Service Date (ISD) of April 2003. Following technical and resource problems, BAE SYSTEMS advised the Defence Procurement Agency (DPA) in late 1998 that they could not meet this date. As of March 1999 the estimated cost of procurement of Nimrod MRA4 was #2.4 billion (at September 1998 economic conditions), an increase of 0.5% since the contract was placed in December 1996.

By 1999, however, the program was three years behind schedule. Resource and technical difficulties with the early phases of the program at BAe meant that the company did not expect the aircraft to enter service with the RAF before early 2005. The precise slippage was the subject of negotiations between MoD and BAe." In May 1999, following extensive negotiations the contract was re-baselined with an ISD of March 2005, a delay of 23 months and with the MoD securing various benefits in compensation. The DPA worked very closely with BAE SYSTEMS to ensure that all possible measures are taken to support delivery of the full operational capability in the required timescales, consistent with a March 2005 ISD. Nimrod MRA4 was due to enter operational service in August 2004. The In Service Date (ISD) of March 2005 was intended to mark the delivery of the 7th aircraft, with the 21st and final aircraft due for delivery in December 2008.

By the end of 2002, it was clear that a combination of factors arising from the overlap of development and production activities was leading to further scheduling difficulties. In response to this, agreement was reached in February 2003 between BAE SYSTEMS and the MoD to make changes to the contract structure. The new contract agreement consists solely of design and development using the first three aircraft for development flight trials. In addition to demonstrating cost and schedule performance, it is expected that once an acceptable level of product maturity had been proven through flight trials, that the contract for the production of the remaining aircraft will be awarded.

Under the Defence White Paper of December 2003, the Nimrod MR2 fleet would be reduced from 21 to 16 aircraft and the requirement for the Nimrod MR4A was downsized from 18 to 12. In September 2004, the planned order for Nimrod MRA4 was reduced from 18 to "about 12".

The Nimrod MRA4 flight test program comprises three development aircraft, PA01, PA02 and PA03. PA01 which flew for the first time in the summer of 2004 is the principal air-vehicle test aircraft and was used for handling trials, flutter, performance, stalling and general systems testing. PA01 temporarily differed from the production standard MRA4 because the majority of the mission system has been removed and replaced with a comprehensive suite of instrumentation equipment and flight test workstations. The second development aircraft (PA02) flew for the first time at the end of 2004 and was the first mission systems aircraft to fly. In addition to mission systems testing, PA2 is the primary trials aircraft for hot/cold climatic trials and weapon store safe separation testing. PA03 was expected to make it's first flight during the summer of 2005. PA3's primary trials involve the testing of Mission System Avionics (MSA), with a bias towards DASS and ESM clearance. The aircraft is also being used for Avionics Testing (navigation-aids and AFCS) and Human Engineering Noise and Vibration Trials. PA3 is the dedicated aircraft for lightning testing. PA02 joined the program in December 2004, achieving one of the major business objectives for the project - flying the first two aircraft before the end of 2004.

The original planned in-service date for the MRA4 was April 2003, but was delayed five times and as of 2009 stood at 2010. This has meant that the out-of-service date of the existing MR2 fleet has had commensurately to be put back several times and Nimrod MR2 aircraft had to remain in service far longer than anticipated. The number of aircraft being procured was progressively reduced from 21 to nine and the unit cost was now three times the figure expected when the investment decision was made.

The aircraft was due to enter service in December 2010. However, in December 2009, the Department decided to delay the project as one of a range of measures aimed at reprioritising Defence expenditure to focus on current operations. Consequently, the In-Service Date will now be achieved some 22 months later than planned, in October 2012.

The decision to delay the project was a pragmatic one taken by the Department in difficult circumstances and was made following an analysis of the options. The decision freed up £110 million to be used for other, higher priority tasks and equipment projects, but it was not without risk to maintaining the integrity of the United Kingdom through detection of hostile surface and sub-surface vessels. Although the Department re-tasked other fixed and rotary-wing aircraft to cover some of the Nimrod’s missions this has resulted in an overall reduction in anti-submarine and long range search-and-rescue capabilities.

The Nimrod MRA4 program was cancelled in October 2010. The government stated that the decision had been taken to save money. Despite appeals from many people, the government ordered the immediate destruction of the aircraft. The Government had no plans to lease or purchase P-3 Orion, Airbus A319 MPA or P-8 Poseidon aircraft. However, following the decision not to bring the Nimrod MRA4 into service the Government was keeping our future requirement for maritime patrol aircraft under review.

Royal United Services Institute analysis report by Lee Willett, January 2011 said about the loss of the MRA4 ASW capability: "The submarine threat is a significant national security issue, not just a Cold Warrior's hangover. ... Despite MoD statements that Nimrod's roles will be covered by other assets, no other assets deliver its specific capabilities. The UK's ASW web hence has a particular, and significant, hole in it. In Nimrod, the refined sensor capabilities - both actual in the MR2 and planned in the MRA4 - together with the aircraft's range, speed and endurance, gave the UK an asset which could operate from strategic to tactical levels. Operating in all three environments - air, surface and sub-surface - it could reach targets, even distant ones, quickly and could maintain pressure on the target while vectoring in other assets.... The Type 23/Merlin package does not match Nimrod's capability."

The Government stated in 2012 that "We regret that we had to cancel the Nimrod MRA4 programme. It was a capability that we would, in an ideal world, have preferred to acquire. ... It is true that there is currently no single asset or collection of assets that fully mitigate the resulting capability gap. This is an unwelcome consequence of the Nation's financial position and the Department's obligations to contribute to deficit reduction, but we continue to maximise the use of other assets such as Type 23 Frigates, Merlin Helicopters, Sentry and C-130 to contribute to Anti-Submarine Warfare, Search and Rescue and Maritime Counter-Terrorism where possible. In the longer term, if the Government were to conclude that it needed to close the gaps completely because future threats were to mature in a way that we can no longer manage this risk in the way we are today, some additional funding or reprioritisation would be required."

The National Audit Office's (NAO) Ministry of Defence Major Projects Report 2011 considered the capability gaps left by the Nimrod MRA4 decision. The NAO Report said that according to the MoD, the Nimrod contributed to eight out of the 15 security priority risks set out in the National Security Strategy. It added that the Nimrod was uniquely able to rapidly search large maritime areas, a capability relevant to long range search and rescue, maritime counter-terrorism, gathering strategic intelligence and protecting the nuclear deterrent. The NAO Report further said that the MoD had carried out studies in the lead up to the SDSR to assess the capability gap from cancelling the Nimrod MRA4 and the MoD "assessed that cancelling Nimrod would have consequences for the military tasks that the aircraft was expected to undertake, some of them severe". The Report also outlined the capability gaps resulting from the cancellation of the Nimrod MRA4 and some possible mitigation strategies for covering these.