MOD ANSWERS NIMROD QUESTIONS FROM ANGUS ROBERTSON MP
Posted on Friday, January 18 2008
The Ministry of Defence (MOD) has answered a series of 15 detailed questions relating to Nimrod aircraft from Westminster SNP Leader Angus Robertson. The MP for Moray represents the home base of the entire regular Nimrod fleet at RAF Kinloss.His questions about technical and administrative concerns are relevant to the tragic crash of Nimrod XV230 in Afghanistan which cost the lives of 14 servicemen.Speaking after receiving the detailed MOD response from Armed Forces Minister Bob Ainsworth, Mr Robertson said:“These technical answers from the MOD should help inform the forthcoming independent review held by a leading QC.“I am not certain that all of the points have been answered in full, but clearly the MOD has put considerable time and effort into their response which I am grateful for.“This information is being published on my constituency website www.moraymp.org so that all family members, the defence community at RAF Kinloss and interested observers can read the answers.“I am keen to hear feedback from people associated with the Nimrod fleet to best understand the outstanding technical issues.LETTER AND ANNEX FROM ARMED FORCES MINISTER BOB AINSWORTH TO ANGUS ROBERTSON MP, RECEIVED AT MORAY PARLIAMENTARY OFFICE 18TH JANUARY 2008.Dear Angus,Thank you for attending the briefing into the findings of the Nimrod XV230 Board of Inquiry on 3 December. I hope that you found it useful and that the Board’s briefing and report answered some of the questions you might have regarding the incident.At that briefing you passed me a letter containing fifteen questions on the safety of the Nimrod aircraft. I have addressed each of these questions in turn in the attached Annex.As you will be aware from the statement Des Browne made to the House on 4 December, we intend to ensure that we learn all the wider lessons from this tragedy. Accordingly an independent review led by Charles Haddon-Cave QC will investigate the arrangements for assuring the airworthiness and safe operation of the Nimrod aircraft over its servicelife; assess where responsibility lies for any failures; assess more broadly the process for compiling safety cases, taking account of best practice in the civilian and military world; and make recommendations. This review will be able to recommend a public inquiry if it is considered necessary and will keep the families of those who died informed ofprogress. The findings of the review will be published, subject to considerations of operational security.I hope this information is helpful. [original signed]The Rt Hon Bob Ainsworth MP AnnexQ. 1 A BAe report in 2004 on the Nimrod MR2 fleet recommended the fitting of fire extinguishers in the bomb bay. Why was none ever fitted by the RAF despite this recommendation? Was cost saving the priority?Q. 10 In August 2004, BAE Systems issued a Safety Case report covering fire/ explosion hazards on Nimrod MR Mk2 and R Mkl aircraft. The report recommended that the bomb bay fire suppression system fitted for extended range tankage role be utilised in normal operation. Failure to do so could result in an uncontrollable bomb bay fire to the point of leading to loss of an aircraft. This recommendation was rejected by MOD on the grounds that is was thought that such a system would be ineffective. Can MOD state whether this conclusion was arrived at following system trials, or was it simply arrived at through some form of paper exercise?Although there is a fire detection system fitted to the Bomb Bay of the Nimrod MR2, there is no fire suppression system. Even if a Bomb Bay fire suppression system had been fitted, it is highly unlikely to have prevented the loss of XV230 as the BOI concluded that the fire was not located in the Bomb Bay,The BAE Systems 2004 report to which you refer is part of the Nimrod MR2 Baseline Safety Case, which was accepted by the Department in 2005. This report recommended that the Department consider fitting a special role-fit fire suppression system designed for use in the Nimrod MR1, specifically when extended range fuel tanks were fitted in its Bomb Bay.This fire suppression system was not designed to be used without the MR1 extended-range bomb bay fuel tanks fitted. It is likely that the larger volume of air in a Bomb Bay without such tanks would render the fire suppression system less effective.The decision not to fit this system in the Nimrod MR2 Bomb Bay was based on the final assessment of the hazard identified in the Safety Case which concluded that the risk was at a sufficiently low level such that it was considered not to require further mitigation. Cost was not the deciding factor. Indeed, there is no suggestion within the Board of Inquiry report that lack of resources was a factor in the loss of this aircraft. The decision not to fit the Nimrod MR1 role fit fire suppression system in the Nimrod MR2 Bomb Bay will be revisited as part of the internal Safety Case Review which has recently initiated and is expected to have completed by April 2008.Q. 2 The BAe report also recommended that the RAF keep a watching brief on fuel tank protection directives in the commercial aviation sector. For the crew of XV230, a fuel tank protection system would have provided a second layer of defence from a fire on-board, potentially giving them the time to make an emergency landing. Why was this recommendation also apparently ignored – despite the fact that the RAF had already lost Hercules XV179 to a fuel tank explosion in January 2005?Q. 11 The same report recommended that in the light of the TWA 800 in-flight fuel tank explosion, that fuel tank nitrogen inerting systems should be seriously considered for all new and in-service aircraft, to prevent the occurrence of an explosive vapour in a partially empty tank.Can MoD advise what steps have been taken that to accommodate this recommendation?The recommendation made by BAE Systems in their report was to retain a watching brief on possible changes to Civil Aviation Authority (CAA) rules with regard to fuel tank protection. This watching brief has been maintained since the safety case was produced. This issue is still underdiscussion between the CAA and the European Aviation Safety Agency (EASA) and there are no changes to the CAA regulations to mandate fuel tank protection. Given the BOI findings of the probable cause, such a system would not have prevented the loss of XV230.Q. 3 The BAe report also highlighted the supply of hot air to the supplementary conditioning pack (SCP) as a cause for concern when it spoke of the risk of adjacent hot air pipes to fuel tanks as a source of ignition, following an incident in which this happened. Why – when stopping the use of the SCP was a no-cost safety measure – did the RAF donothing until they lost a crew? Now, apparently, the SCP on the MR2 is no longer used – suggesting the RAF only heeded BAe’s recommendation when it was too late.The BAE Systems report did identify high temperature heat radiation from bleed air distribution system leakage adjacent to fuel tank structures as a potential ignition source in the wings. However, the report states that this hazard was mitigated by design separation between bleed airdistribution and wing fuel tanks so that the fuel heating risk is minimised. It also cites periodic maintenance inspection and test of the air bleed system as procedural mitigation of the risk of bleed air system leakage system. It did not assess the risk as high enough to recommend further mitigation measures and that is why no further action was taken at the time.The BOI concluded that the report underestimated the hazard associated with escaped fuel coming into contact with the Supplementary Conditioning Pack (SCP) Duct. This will be one of the key areas for investigation by the independent review announced on 4 December.Following the loss of Nimrod XV230, use of hot air systems such as the SCP, engine cross-feed and Bomb Bay heating have been permanently suspended across the fleet in order to further mitigate any risk caused by leakage of flammable fluids. These systems still have a part to play in operating the aircraft in certain circumstances, but the RAF can accommodate the operational impact of not using them.Q. 4 After the more recent emergency landing by a Nimrod MR2 last month, when fuel started spraying into the bomb bay during air to air refuelling, the RAF was unable to replicate the fault on the ground – meaning that it was unable to fix it. Why was the fleet not grounded at this stage?Following the diversion to Kandahar of a Nimrod MR2 on 5 November 2007, when it was discovered that fuel was leaking into the Bomb Bay during Air to Air Refuelling (AAR), a full investigation is being conducted into the cause of the fuel leak. As a precautionary measure air-to-air refuelling of the Nimrod fleet has been suspended and will not be resumed until we are absolutely sure it is safe. The Chief of the Air Staff has confirmed that the Nimrod aircraft remain safe to fly given all the precautions that have been taken following the BOI.Q.5 Were such faults to be discovered on a civil airliner, e.g. a lack of fire extinguishers, the fleet would be grounded. Why is it deemed acceptable for military crews to run avoidable risks on top of the majorrisks they already agree to run by serving on operations in a war zone? Is operational tempo driving this, and should the MoD still be allowed to regulate itself in terms of RAF aircrafts’ exemption from current civil aviation standards?The Nimrod is fitted with fire extinguishers where these are required to mitigate the risk of fire. Fire suppression is considered where fire avoidance cannot be used to mitigate the risk to tolerable levels.Although it is true that our Armed Forces are currently operating at a high tempo, the Board of Inquiry did not consider operational pressures to have been a contributory cause or factor in the loss of Nimrod XV230. Operational flying is not without risk but the safety of our personnelremains our highest priority. The independent QC-led review announced on 4 December will also assess more broadly the process for compiling safety cases, taking account of best practice in the civilian and military world.Q. 6 The ageing Nimrod MR2, now 37 years old, was due to leave service a decade ago – why is its replacement, the Nimrod MRA4, not coming into service until 2011 at the earliest – was this an example of inadequate procurement? And is it deemed safe to fly the current ageing fleet indemanding and difficult conditions for another four years or is this a decision being driven by the need to save money?The Nimrod MR1 entered service in 1969 and was upgraded to MR2 standard in the late 1970s. However, the calendar age of an aircraft is not an indicator of its operational utility, its condition or its remaining service life. Aircraft can, for example, be extended in service throughspecific programmes to extend fatigue-life and additional or upgraded capabilities can be fitted to older aircraft. The Nimrod MR2 is maintained to strict airworthiness standards and if we did not have confidence in the aircraft, we would not allow it to be flown.Under the planning for its replacement, as set out at the time of the original Nimrod MRA4 contract, the MR2 would not have been due to reach its Out of Service Date (OSD) until the middle of this decade, towards the end of the time when the Nimrod MRA4 deliveries were due to have completed. The current planned In Service Date for the Nimrod MRA4 is 2010. The delay in bringing the aircraft into service, while disappointing, was necessary to ensure technical issues were resolved prior to full production of the aircraft, which began last year.Q. 7 Another maintenance report on the MR2 on the MR2 fleet, carried out by QinetiQ in March 2006, six months ahead of the loss of the XV230, highlighted the extent of fuel leaks on board the fleet – a known problem – and in particular on the six aircraft flying intensive schedules over Afghanistan and Iraq. The leaks, the document says, represented a “critical” structural problem – dating back at least ten years, along with problems with the seals and sealants on the pipework. The report said those leaks were made worse by air-to-air refuelling (AAR), something the Nimrod was not originally designed to do. Was this report ever acted on by the RAF and why was it deemed necessary to continue air to air refuelling, even though it was known to exacerbate the problem of fuel leaks?The QinetiQ Nimrod Fuel Tank Leak Study Report dated 17th March 2006 was commissioned to examine the maintenance processes, procedures and working practices relating to the repair of fuel leaks in wing tanks. The objective of the study was to improve the effectiveness of the aircraftmaintenance processes and thereby increase the availability of aircraft to the Front Line. It did not cover fuselage tanks, pipes or couplings and was not initiated because of any aircraft safety or airworthiness concerns.The report did not state that fuel leaks represented a "critical" structural problem nor that the 'leaks were made worse by AAR, something the Nimrod was not originally designed to do. It stated that ‘proper interrogation of the existing data (that records significant fuel leaks from Ribs 7 and 12 areas) would have highlighted a structural problem that needed to be addressed before it became critical.’ The report discussed how fuel leaks at lower wing skin joints might be indicative of a potential mechanism for fuel or moisture induced corrosion. This potential corrosion problem is planned to be investigated as part of a detailed structural examination of Nimrod wings next year.None of the study recommendations impacted directly on airworthiness but as a consequence of the report, the Nimrod Fuel Management Working Group, with representation from RAF Kinloss, BAE Systems and the Nimrod IPT, was introduced to implement the report recommendations as a continuous improvement programme for wing fuel tank repairs. In particular, new procedures have been developed and appropriate changes have been submitted for publication in the next Air Publications update.Q. 8 In February 2006, seven months before XV230 crashed in Afghanistan, the Government organisation QinetiQ were invited to Kinloss by the Nimrod IPT to carry out a survey of several aircraft and advise on the growing number of fuel leak problems in the Nimrod fleet. One of the aircraftinvolved in the survey was Nimrod XV230. In March 2006, QinetiQ produced a very detailed visit report which contained several recommendations. Can MOD advise as to which of these recommendations have been implemented, some 20 months after the report was issued? In particular the use of outdated servicing documents and tools, and the lack of shared data between civilian contractors at Kinloss with the IPT, MOD and BAEThe visit by personnel from QinetiQ (now a mostly privately owned organisation) to RAF Kinloss in February 2006 was part of the Nimrod Fuel Tank Leak Study which was published in March 2006 and has been discussed in answer to question 7.Q. 9 Prior to going to the Gulf on 3rd August 2006, Nimrod XV230 underwent a new form of servicing, drawn up by the Nimrod IPT, known as equalised maintenance. The maintenance period lasted some eight weeks and was carried out by a civilian contractor at Kinloss. Prior to entering this planned maintenance programme the aircraft had just returned back from the Gulf and had nine reported fuel defects. After eight weeks on the ground the aircraft left the civilian contractor with seven of those defects unrectified. Can MOD advise why this was allowed to happen, considering that this was the first aircraft to undergo the new programme and should have been closely monitored by the IPT? Can MoD also confirm that the contract does call for a fully serviceable aircraft on completion of maintenance, or has this been missed from the contract?A key feature of the Nimrod maintenance policy is that any leaks found beyond the acceptable limits defined in the Nimrod Maintenance Procedures must be rectified before the aircraft can fly.Nimrod XV230 was the first Nimrod aircraft to enter Equalised Maintenance, and did so on 26 May 2006. Under Equalised Maintenance there are six different packages of work known as EQ1 to EQ6, which are carried out in sequence every 600 flying hours. The rectification of acceptable fuel tank leaks is planned to be carried out during EQ3 and EQ6 and this is what has been contracted for.When XV230 entered EQ1, nine minor leaks from the wing fuel tanks were present. They were within acceptable limits and not considered to compromise aircraft safety. Their repair was not part of the EQ1 maintenance schedule. However it was recognised that two of the leaks would affect the operational capabilities of the aircraft and these twoleaks were rectified before the aircraft returned to theatre.Q.12 It is understood that the Nimrod R Mk1 is to receive a new mission fit under “project Helix” this should extend its operational life to 2025. In view of the comments made in the QinetiQ report regarding possible corrosion in wing fuel tanks and the age of the aircraft, how does the MOD expect the Nimrod R airframe to last to 2025? The R and the MR are two different aircraft types, but the basic airframe! fuel systems are the same.Project HELIX is aimed at continuing the capability currently provided by the Nimrod R1 up to 2025 - namely Airborne Electronic Surveillance. The programme is not yet at the Main Gate Investment decision point, so no definite decisions have yet been made regarding the selection of themission system or host platform for that capability. We are currently assessing our options and expect Main Gate to occur before the end of the decade.Q. 13 In a 2005 report into an incident involving a corroded super hot air pipe in the Supplementary Cooling Pack (SPC) of XV227 it was recommended that a survey was to be undertaken to determine what similar pipes (ducts) were in the same condition. It appears that it has taken two years to undertake such a survey on just two aircraft, and as yet no revised inspection programme has been initiated. At the time of XV230’s accident the SPC was still being used, but was isolated on all Nimrod aircraft immediately afterwards. Can MOD advise as to who was responsible for making the decision to continue using the SPC after the XV227 accident, as clearly, from the actions taken later it was a high risk component?Nimrod XV227's SCP duct failure was an isolated incident and occurred in the only part of the SCP system where a leak would not have been detected in flight by the aircrew. A leak anywhere else in the SCP system would be detected and the system immediately turned off. After the incident, useof the SCP was suspended until this duct had been replaced throughout the fleet with newly manufactured items. Based upon the previous 25 fault-free years that the original duct had been fitted, these new ducts were expected to have lasted well beyond the planned Nimrod MR2 OSD (early in the next decade). This was considered to have mitigated any immediate risk of a similar hot air leak from this duct hazarding other aircraft.A study into the need for a longer term preventative maintenance/lifing policy for this and similar ducts was undertaken by the Designer (BAE Systems) who subsequently recommended a lifing policy for ducts. However, following the loss of Nimrod XV230, except for cross feed engine starting in an emergency use in the air of hot air systems such as the SCP, engine cross-feed and Bomb Bay heating have been permanently suspended in order to further mitigate any risk caused by leakage of flammable fluids.Q.14 On the 5th Nov, this year, there was a fuel leak incident over Afghanistan involving XV235. Like many of the in-flight fuel leaks the incident happened after AAR, and MR was suspended. In the past MR has resumed after ground test and MR procedures have been revised, clearly without getting to the real problem. Can MOD new procedures are now being considered by the IPT to get MR operational, and how sure are they that they have got it right this time?The incidents that led to AAR being suspended in 2006 were different to the one experienced by XV235 on 5 November 2007. Measures were introduced to make air-to-air refuelling as safe as possible, including limiting the quantity of fuel transferred and the flow rate at which this is done. Since the leak incident on Nimrod XV235 on 5 November 2007 all AAR has been suspended until completion of a full investigation and AAR will not be resumed until we are absolutely confident that it is safe to do so.Q. 15 MR was introduced to the Nimrod during the Falklands dispute in order to get the aircraft from one theatre of operation to another, not to be used on a regular basis as it is being used today. Can MoD advise as to what changes were made to the Nimrod safety case for (a) using MR for the Falklands, and (b) for today’s regular use, overland?AAR was introduced originally as an Urgent Operational Requirement at the time of the Falklands conflict. It was subsequently formally embodied as a part of the aircraft design but at that time, there was no regulation requiring the formally structured Safety Cases we use today and as such the introduction of AAR was not subject to the more recent system of hazard analysis technique. Incorporation of AAR involved BAE Systems ensuring compliance with Design and Airworthiness Requirements for Service Aircraft, through certification and qualification underpinned by ground testing and flight trials.The Department elected in 2001 to undertake Safety Case assessments by April 2005 for older in-service aircraft, (including the Nimrod MR2). Nimrod was one of the first legacy aircraft in RAF service to have a Safety Case following changes in the MOD’s Airworthiness Regulations. The Safety Case was constructed by BAE Systems, the Nimrod Designer. The Baseline Safety Case was accepted by the Nimrod IPT in 2005. As AAR was already installed, it was considered as part of the BAE Systems Nimrod Baseline Safety Case Report.
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