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Nimrod crash in Afghanistan Tech/Info/Discussion (NOT condolences)

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Nimrod crash in Afghanistan Tech/Info/Discussion (NOT condolences)

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Old 24th May 2008, 09:29
  #681 (permalink)  
 
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What has never been discussed here is how difficult jet fuel is to ignite.
True if just pooled but, if subjected to the 'wicking' effect of, say, lagging then much more likely to ignite.
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Old 24th May 2008, 10:17
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Given that neither system is currently in use, what exactly are the remaining risks that justify the grounding of the fleet?


Well there are the seals for a start; the manufacturer stated on oath that they are not suitable for the purpose that they are being used on the Nimrod. When Grp Captain Hickman describes how the seals on the blow-offs are tested by passing air through them (that’s right seals that degrade after 5 days dry have air blown over them to test them!) oh then everybody has to be quite while the engineer listens for a whistling sound!

He was almost laughed out of the court room. I repeat what I said in the press conference yesterday Hickman as head of the IPT is arrogant and has a casual attitude towards safety, if my life was in that comedians hands I would get a seriously good life insurance policy, although that may be difficult for serving air crew now as it has been proven that they are flying in an aircraft that is not airworthy!

If Gp Capt Hickman, as the Delegated Airworthiness Authority, has stated that the Nimrod currently IS NOT ALARP, we are in trouble. I wasn't there to hear his words on oath, but if he used those words, or similar, he is contradicting virtually everyone (from SoS down to NLS liney) involved with the aircraft. Given his appointment, there should be no way that he would be contradicted by his superiors. I believe he has been mis-represented here.


I was in court and Group Captain Hickman stated that the “Nimrod is tolerably safe but not ALARP” he went on to describe that they hope to be ALARP by the end of 2008. Only took them 40 years to achieve!!!


Buey15 – you’re a disgrace to your service, your comments are an insult to crew 3 and their families, and you should be ashamed.
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Old 24th May 2008, 11:24
  #683 (permalink)  
 
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Buoy 15

You say...."Spitfires and Hurricanes in WW2 were not fitted with foam/fire depressant, but we don't see those pilots widows trying to wring money out of the MoD"......

Well, Spitfires and Hurricanes in WW2 did have self sealing fuel tanks,

http://en.wikipedia.org/wiki/Self-sealing_fuel_tank

which was the equivalent of foam at the time (and is more than the RAF Nimrod/Herc/etc fleet had until very recently, and is now only going onto Hercs, but not MRA4) - once again your ignorance shines through. As has already been stated, none of the relatives are in this for the money, and for you to suggest so ............ frankly your suggestion leaves me speechless, and once again speaks volumes about you.

You give me the impression of someone who has the same attitude as RFC/RAF senior officers in WW1. That attitude being one of, ....'we won't give the pilots parachutes as they may bail out at the first sign of a fight'.... How many unneccesary deaths did that approach cause???
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Old 24th May 2008, 12:32
  #684 (permalink)  
 
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The coroner was right.
Buoy 15 is a knob.
Any questions?
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Old 24th May 2008, 12:34
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I would get a seriously good life insurance policy, although that may be difficult for serving air crew now as it has been proven that they are flying in an aircraft that is not airworthy!
More importantly Da4orce, where do people stand with existing Life Insurance policies? God forbid there were to be another crash, but should it happen, that would conclusively prove that the MOD and the Government should not have continued to risk flying an aircraft that is only Tolerably Safe.

At the individual level, your Life Insurance company might then decide that while you personally accepted the risk of flying in such an aircraft, they did not. Worst case, that could result in a refusal to pay out. Any Financial Advisors out there that could offer a view on this?
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Old 24th May 2008, 13:48
  #686 (permalink)  
 
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Nimrod Airworthiness

I find the whole debate on this thread over Nimrod airworthiness confused and unclear.
My understanding is that the original Comet design was extensively modified to generate a military aircraft type called Nimrod. To permit self-start, the Nimrod MR1 had an auxiliary power unit and a hot air cross-feed system installed. In the installation of the cross-feed system, the hot air ducts come close to fuel pipes, particularly in the vicinity of the starboard 7 tank (another addition to Nimrod). The airworthiness requirement for the interaction of the hot air system and the fuel system was defined in Design and Airworthiness Standards within AvP 970 (now extensively amended and published as Def Stan 00-970). The records of the clearance of the original design between the MOD and Hawker Siddley are not all available and the evidence available does not cover proximity of hot air and fuel systems. Thus, the situation is that either the proximity of the hot air system and the fuel system was not recognised or it was recognised and accepted by the MOD as an exception to AvP 970. In either case, the failing happened in the late 1960s. The aircraft then flew in a state where it was not compliant with the airworthiness standards in AvP 970 for many years.
The subsequent introduction of air-to-air refuelling in Nimrod may have increased the peak fuel pressures experienced by the aircraft refuel system.
When the Nimrod MR1 was converted into the Nimrod MR2, the situation was exacerbated when a Secondary Cooling Pack was added in the rear fuselage powered from the cross-feed ducts. This meant that whenever the Secondary Cooling Pack was in use, the Cross-Feed Ducts had to be pressurised by hot air. This extended the period when the fuel system was exposed to air ducts containing hot air. Again, the records of the clearance of the original design between the MOD and the manufacturer are not all available. The conversion of Nimrod MR1 to MR2 was an opportunity to identify the airworthiness issue and resolve it. The aircraft continued to fly in a state where it was not compliant with the airworthiness standards in AvP 970.
Much later, the Nimrod IPT had a safety case produced to document the justification of the airworthiness of Nimrod. During this exercise, a failing of the risk assessment occurred within the Nimrod IPT. This inadequate risk assessment resulted in a missed opportunity to recognise that adequate measures were not in place to cater for the close proximity of the fuel system and the hot air system. The aircraft continued to fly in a state where it was not compliant with the airworthiness standards in Def Stan 00-970.
The accident to XV230 was caused by an explosion resulting from a fuel fire most probably in the area where the fuel system and hot air systems are in close proximity near the 7 tank. There was not enough evidence to either the Board of Inquiry or the Inquest to define precisely where the fuel leaked or the ignition source. Thus, the accident sequence will never be known for certain.
After the accident a number of actions have been taken. Air-to-air refuelling is no longer carried out by Nimrods. The Secondary Cooling Pack is no longer used. The cross-feed system is only pressurised and used for engine start on the ground. The fuel system has an increased 30-day maintenance inspection regime. In addition on scheduled maintenance, there is a fuel system inspection and targeted fuel seal replacement programme under way. There is a plan to replace all hot air ducts as soon as reasonably practicable after they are available.
So where is the Nimrod force now. The immediate actions regarding the use of the hot air system where taken to remove the risks of proximity of hot air system and fuel system in flight. There is a programme to make further improvements. Does that make the Nimrod airworthy? Airworthiness is a risk management process. The aim is to manage the risk to a level that is both tolerable and as low as reasonably practicable. Should time for embodiment of safety enhancements be a factor in “reasonably practicable”? On a military aircraft, should the acceptability of risk be balanced against the potential operational benefit? These are big questions that must be answered as soon as possible. I have opinions as will many other individuals; our opinions are only that! I do not envy Charles Haddon-Cave QC his task.
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Old 24th May 2008, 13:54
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Thats a pretty detailed first post Woodbine. Sure you arent in main building and not in Lossiemouth?

I suppose the main question should be were there concerns about the system expressed by individuals prior to the accident? If so, the MOD should be hung, drwan and quartered if they got round it by justifying "operational risk".
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Old 24th May 2008, 14:01
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TB - you will never reach senior rank with clear, concise and pertinent judgements like that.
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Old 24th May 2008, 14:20
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Airworthiness is a risk management process. The aim is to manage the risk to a level that is both tolerable and as low as reasonably practicable.
Perhaps a more simple test would answer your unspoken, and unanswered questions: was the airframe and engine combination fit for the purpose for which it was it intended?

Patently not.

Modified and altered from the original Comet airframe and engine combination, additional components added and finally made AAR capable, yet without any apparent stringent examination of potential problems or technical competence.

Years of make do and mend for the RAF may finally have reached their peak: the " press on regardless attitude" of Their Airships, "Of course we can do it" WW2 machismo is not, and has not been, valid for many, many years.
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Old 24th May 2008, 14:48
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Some on here are missing an important point.
Whether or not the aircraft meets some definition of safe is unimportant in my view compared to whether not having it flying makes the guys on the ground safer.
They are the ones who are facing by far the biggest risk of death or injury.
If, by flying the Nimrod we accept a higher risk than we would like, but lower their frankly horrendous risk levels, we should do it.
I find it a little uncomfortable that members of the armed forces are unwilling to accept risk of death just down to bloody ALARP or whatever. The soldiers don't get to discuss alarp before they go on patrol, or they would never go. Why should we of the flying fraternity be any different? Half the military aircraft and mission roles in history would never meet the modern definition of safe.
Anyone who calls for the grounding of the fleet whilst we have no replacement needs to take a look at themselves. There are plenty of unsuitable/unsafe a/c types in theatre (SK4 for one) but they are required. If you don't want to fly them then PVR.
I was recently informed that the soldiers death or severe injury chance is currently 11% during their time in sandy places.
Until our risk level hits theirs, then fly the Nimrod.
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Old 24th May 2008, 14:53
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Basil states:
True if just pooled but, if subjected to the 'wicking' effect of, say, lagging then much more likely to ignite.
Even with a wicking effect, there the fuel will spontaneously ignite after a certain elapse time depending on temperature. Over 550C, this time less than a second, at 400C it is several minutes and below 300C it is 10s of minutes.
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Old 24th May 2008, 15:14
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I understand the view put forward by Tourist who raises a good point. That said, just because one set of people are operating in a high-risk area does not mean that we should risk others. The Nimrod was placed in theatre to mitigate risk to ground troops. In doing that, the risk to others has increased alarmingly. I am not saying don't operate Nimrods at all, only that taskers should specifically identify the benefit of each mission. We currently operate approximately 18 Nimrods....2 on a good day !!! Should we not start to think about drastically cutting the fleet to say 6-8 aircraft and provide the engineers with the time and resources to keep the airframe in the best of conditions until the MRA4 enters service (and it will enter service). The current state of the MR2 fleet, at present, is a quite simply unfit for mission.
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Old 24th May 2008, 16:16
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Tourist,

You quote....'The soldiers don't get to discuss alarp before they go on patrol'...which is correct, but only up to a point. Airman don't get to discuss ALARP before they go flying either, those decisions/actions are taken by MOD/IPT, etc.

As to the MODs/Governments/Armys approach to something akin to ALARP for the troops, well they are doing it!! It is the reason why Bulldogs/Mastiffs (spelling?)/improved body armour/reduction in use of Landrovers, etc have all occurred - to reduce the risk to the troops on the ground. In the same way DAS systems on aircraft have been updated/added/improved, Hercs are now getting foam, etc.

But how many of these risk reduction measures for troops on the ground are directly/partly the result of inquests, press comments, statements by relatives, and even, dare I say it, internet forums!!
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Old 24th May 2008, 16:25
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Regarding the investigation by the QC, I thought that it had started in mid Jan and was supposed to take 3 months (finish mid Apr).

Well, according to my calender we are in the back end of May!?
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Old 24th May 2008, 17:05
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Woodbine

There is a programme to make further improvements. Does that make the Nimrod airworthy? Airworthiness is a risk management process. The aim is to manage the risk to a level that is both tolerable and as low as reasonably practicable. Should time for embodiment of safety enhancements be a factor in “reasonably practicable”? On a military aircraft, should the acceptability of risk be balanced against the potential operational benefit?


I have touched on this before and I can offer what I have done when faced with similar situations. The general principle is that you are given a “reasonable time” to comply. Yes, cost and operational benefit are allowable considerations, but there is an overarching Duty of Care. This becomes emotive, as people are asked to place a price on a man’s life. DECs, understandably, don’t like having to justify requirements in this context but it is unavoidable and much effort goes into quantifying the benefits.
But there are many scenarios to consider so I’ll just give a few;

a. Complying with new legislation. That is, the aircraft is airworthy/safe/fit for purpose in that it complies with the “standards of the day”. Then new legislation makes it non-compliant. Good examples were the Montreal Protocol (CFCs) and use of Cadmium. Most effort is concentrated on updating standards for future contracts and, if you’re lucky, changing ongoing contracts. Design Authorities were tasked to compile a list of non-compliant kit and a case by case view was taken on what to do. In short, little retrospective action was taken (correctly in my view).

b. Long standing legislation or requirements that have been deemed impossible to implement in aircraft because, typically, there is no engineering solution. Then one comes along and risk mitigation is suddenly viable. A good example is miniaturisation of electronics. What took up a room 50 years ago can be fitted in a matchbox these days. Related to this are limitations imposed by available electrical power. In these cases, you are given a reasonable time (depending on the class of risk of course, which may indicate no action required). A useful tool is to make the modification classification system work for you by applying a classification such as “embody at next major”, thus maintaining operational capability while being seen to comply. Typically, an EP bid would be made in the next planning round > funding approved > development > production etc. It would not be unusual for a “reasonable time” to be some years as the engineering solution may be novel and ground breaking. For litigation purposes, the clock starts running after a “reasonable time” has expired.

c. A genuinely unforeseen event happens resulting in, for example, a Serious Incident Signal. Much the same as b.

d. A design error has been admitted, compounding a known risk. It is belatedly recognised and mitigation commences. This one applies to Nimrod, as far as I can see. Implementation is the same as b. but for litigation purposes the clock started running when the error was made and the MoD’s positioned is weakened by every days delay.



The common denominator here is that each requires immediate access to the relevant Design Authorities or Design Custodians. This does NOT mean having to initiate a contract, which can take many months. It REQUIRES a contract which can be invoked IMMEDIATELY. I don’t just mean by MoD making a phone call, convening meetings and faffing about negotiating a price, but calling up the correct Standards and Specifications in a suitable contract which permits the Design Authority to self task and commit resources in the certain knowledge he will be paid. The relevant Specification (Spec 5) covers just this and sets a financial limit which equates to an amount of man-hours, giving MoD time to get its act together. The SOLE purpose of this contract is to Maintain the Build Standard and I live in hope that the Nimrod accident will somehow prompt MoD to overturn the RAF’s 1991 decision to slash funding and progressively run down this fundamental and mandated airworthiness process. Note – the DA representative with this unique delegated authority to commit MoD funding (assuming the correct contract is in place) is an MoD appointment, of a Company employee. MoD hold the power of God over him/her and can revoke his authority at any time – far more authority to “hire and fire” than MoD has over its own staff. Ironic, given the criminal acts it routinely condones.
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Old 24th May 2008, 17:10
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Tofo:
Did a 3 engine ferry from Leuchars once, 25 minutes apparently. I always thought it sad when the survival flyoff turned into the survival fast taxy... It was hard to look cool on a Nimrod (imo) but there was something impressive about a whole bunch getting airborne in rapid succession.

As for those who belong to an older, darker age, when clipping on a parachute was akin to sticking an 'I'm a big puff' badge above your brevet....and apologies if I misquote these annual report gems....

'I would not breed from this officer'

and

'His men would follow him anywhere, but only out of a morbid sense of curiosity'.

Dave
(edited to add a missing word)
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Old 24th May 2008, 18:00
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I'm confused as to the status of the aircraft & ALARP at the moment.

Are the "30 recs to get to ALARP" known? If the only outstanding ones relate to AAR (which I've read somewhere), then as if the aircraft doesn't do AAR then it would then be ALARP and can continue safe operation - is this the thrust of the MoD position relating to continued operations?

If this is not the case, what are the outstanding ones, and what is their impact on the safety of current operations? Are they really "ALARP" issues in the true sense?
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Old 24th May 2008, 18:16
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JFZ90

The important point is that the "30 requirements" cited by MoD relate, I believe, to one part of the problem. QinetiQ could just have easily added a 31st - "Comply with all our previous recommendations in the following reports.......". And if certain people in MoD had seen it, they would have said "As advised to 2 and 4 Stars yonks ago".

Most of the 30 relate to airworthiness process implementation and are therefore generic (not specific to Nimrod). In a previous post I cited a further raft of recommendations relating to the Nimrod Fuel System - listed under 3 headings each of which are fundamental airworthiness components. This report References previous reports covering the same subject (including reference to another aircraft - VC10) which presumably contain more recommendations. It is these which I understand have not been released under FoI, inferring they are even more damning (which, I admit, is hard to imagine, but then I would have said that about the 2006 report before I read it).
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Old 24th May 2008, 18:16
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Only six of them relate to AAR and as you say those six are not really important any more. The other 24 all relate to other elements of the fuel system and I think Tuc pointed out that all but one of the 30 relate to a failure to implement mandated airworthiness regulations. I can't tell you whether the one that isnt is AAR related or not but I'm sure he could.

[Posted while Tuc was making his post!]
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Old 24th May 2008, 18:26
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Thanks for the kind words, folks

This thread is moving on at such a pace it’s a bit hard to keep up. But before we leave the inquest altogether, there is something else I would like to share from my days there. It’s actually the second time this has happened to me this year.

There’s a word that’s much overused by politicians and celebs, and when they use it, they usually mean exactly the opposite. But in this case, it’s the only appropriate word. I felt totally humbled by the courage, dignity and strength of the families.

As with the Hercules inquest at Trowbridge, I watched in awe as the Nimrod families coped with everything that was thrown at them. I noted their tears after they had heard the audio recording from the mission tape, their utter derision at some of the less impressive witnesses, their steely determination to get at any truths that might have slipped past the coroner, and also, of course, their humour - aided by the fine, understated sense of humour of the coroner himself. There was even laughter after the verdict.

Two events in particular stay in my mind. One was just before the verdict was announced. One by one, the family members laid big, long-stemmed roses on the steps of the courthouse, the Old Oxford Assizes - one red rose for each of the 14 men who died, and one white rose for each of the 18 children now fatherless. It was..... well, it was deeply touching.

But perhaps best of all was the day before the verdict, when counsel were making their final submissions. There had been divided opinions amongst those who know about these things as to whether Mr Walker was going to go for an ‘unlawful killing’ verdict. But the families let it be known, through their barrister Michael Rawlinson, that they did not want any individuals punished, and they especially did not want ‘unlawful killing’. They did, however, want it to be made loud and clear that there had been, and still were, deep systemic failings in the RAF and MoD system. I would like to think that their gracious but just plea figured highly in the coroner’s deliberations.

It was a privilege to be associated with those families, however peripherally. They made me proud to be British.

airsound
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