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

[bvcu]

and to go on a tangent with the rivet joint you're replacing an ageing a/c with an even older one .......... !!!!! surely its cheaper to put the resources needed into the nimrod fleet .

[EdSett100]

Winco:

how many of those aircraft that you quote have been lost due to a massive fuel leak?

Presumably you are suggesting that XV230 suffered a massive fuel leak. There is no evidence that a "massive" leak started the fire. A QQ scientist proved that 300 ml (contents of a fizzy drink can) can start a massive blaze if it comes into contact with a very hot surface.

You are wrong to imply that XV230 was brought down by a single massive fuel leak.

Ed Sett

[EdSett100]

Keepittidy:

and I not sure if this is 100% fully correct , the Nimrod R1 has more airframe hours than the MR2 and would make sense to be looking for replacement quicker than the MR2 that may be the reason.

No, it would not make sense to replace the R1 quicker on that basis.

Ed

[KeepItTidy]

Ok Edd

Agree to make sense in the Air Force is a silly thing to say as nobody knows that meaning anymore, decisions are based on making things as awkward as possible with least amount of cost

I always thought the R1 had more hours than the MR2s , I must be wrong cause they wanting to use them to 2025, how the hell are they going to manage that ?

Never mind Im sure it will all work out

[Wader2]

KIT, airframe hours is but one measure of fatigue. Pressurisation cycles and operating profile may be highly significant too.

[EdSett100]

KIT:

I always thought the R1 had more hours than the MR2s , I must be wrong cause they wanting to use them to 2025, how the hell are they going to manage that ?

The R1 probably does have more flying hours than the MR2, but it has a longer fatigue life (which is more relevant than hours in the air) due to the way it is used in comparison with the MR2.

OK?

Ed

[Biggus]

And the cost of sustaining the R1 is not affordable (read post 1310 - why do I bother???). The R1 is being replaced on COST grounds. It is not about whether or not it would be feasible to keep it going in engineering terms, but how much that would COST.......

Watch my lips, cost, cost, cost.......

No doubt our political lords and masters may also be glad to see the backs of 'Nimrod' on other grounds, but that is beside the point......!!

[Secretsooty]

It's not just cost grounds, although that is indeed a major part - if you take away 14 or so aircraft (MR2) within the next few years, leaving only 3 (R1) then it becomes increasingly difficult for outside agencies to provide engineering support when the economies of scale are fighting against you.
For instance, do you really think an engine manufacturer would keep a production line open, taking up valuable space that could be utilised more effectively on more lucrative projects, just to trickle-feed a few engines through a year for the next umpteen years when nothing else uses the same engine? No, nor do I, which sort of puts the nail in the coffin of the R1 in my book.

[KeepItTidy]

Well if FI is the limiting limit in these matters I find that strange that the FI in an R1 would be diffrent to that of an MR2, with FI usually calculated with Servicings and Airframe hours, with the R1s coming through a major track the same rate as an MR2 this does not make sense and no major airframe structure any the diffrent especially 49 its an MR2 at heart. Anyway I see the point now of not keeping the R1 in the fleet if only 3 are going to be used.

[Secretsooty]

Keep It Tidy, the FI is worked out against Sortie profile Codes, the R1 and MR2 fly totally different profiles. R1 - mainly low-high-low like a civvy airliner, MR2 - all over the shop, literally! Even some of the engine internals are lifed completely differently dependant on which airframe variant they are fitted to, to the extent the engines have a different mark number even though they appear almost identical in every visual respect.

On the subject of AAR and fuel leaks, Here's a theory of mine to kick around. I wonder if anyone has considered this:-
The pipelines in the bomb-bay will no doubt have been constructed from a material having a similar thermal expansion coefficient to the airframe they are attached to, but what happens when everything is in equilibrium and suddenly there is a change of temperature (and hence dimension) due to the high flow rate of fuel at potentially a considerably different temperature to the airframe....? Is there sufficient flex in all the FRS coupling seals to allow for this dimensional change? Is this why the leaks never seem to be reproduced on the ground? I reckon the old MOD700(?) standard of AAR system with the rubber pipes snaking their way through the cabin was better in this respect, apart from their being located within the cabin, obviously. I sometimes wonder if replacing a fair length of the metal AAR pipework in the bomb-bay with aeroquip would be the proof of the pudding??

[nigegilb]

Some good news for the thread.

Firstly, B15 has been banned from pprune for good after yet another deeply offensive post.

Secondly, it would appear that an awful lot of things are happening within the MoD regarding Nimrod.

The bottom line espoused by the MoD is that "as AAR has been stopped, the Nimrod is now airworthy, so job done." Many of us who care about the way airworthiness has been mishandled in the MoD know that is a deeply flawed statement. The 2nd line might be that airworthiness work concerned with ALARP is complete so Nimrod is airworthy. Again, anyone who read the Hickman transcripts would struggle to make sense of the argument.

I have been critical of CAS, I was staggered by reports of his lamentable performance before the families a few weeks ago. That said, credit where it is due, it would appear that he has implemented many changes and he is working extremely hard to deal with many of the issues raised on this thread and others. It is not the style of Govt Depts to admit they are wrong. I wished I could go further here, but I can't, enough to say that MoD are worried about airworthiness issues and are acting.

I am not convinced that there is enough technical ability to deal with the challenge and it will of course require additional funding, another worry, but I am happy that they are responding.

[Tappers Dad]

Nige
That said there is the small matter of 300 Fuel leaks + the ducting lifting has not been completed +Bob Ainsworth said in Parliament on March 14th 2008 that "The number of Nimrod MR2's planned to be in service with the RAF on 31st March 2008 was 15. The average number of Nimrod Mr2's which were fit for purpose in Feb 2008 was 5.

Bob Ainsworth said in Parliament on May 20th 2008 (The inquest finished 23rd May)
House of Commons Hansard Written Answers for 20 May 2008 (pt 0003)
Nimrod MR2
Number in service 15
Average number of aircraft in Forward Available Fleet 10
Average percentage of total fleet in FAF 63
Average number of aircraft Fit for Purpose 6
Average percentage FFP of Forward Available Fleet 65

So only one more Nimrod fit for purpose 2 months later.

They are still scrapping along when it comes to Fit for Purpose aircraft and leaves the UK very short of Maritime Defense/Reconnaissance Aircraft.

[zedder]

Firstly....'One Nimrod has also been taken out of service and stripped down to check for mechanical problems'......

Use of the word 'has' implies that it has actually happened. To the best of my knowledge it remains an intention. I asked the question before on 12th July, and (as with most of my questions) got no reply. But has the aircraft actually left Kinloss yet, or is it just 'going to' at some point!

The answer is now Yes.

[Tappers Dad]

From the minutes of the meeting with Bob Ainsworth and Sir Gen Torpy
10th July 2008 at the MOD London

Ageing Aircraft
The issue of ageing aircraft was raised. Was the MOD capable of servicing ageing aircraft? In response, the CAS confirmed that the MOD was doing a huge amount on the issue of ageing aircraft. On Nimrod, specifically, we had decided to carry out a complete tear-down of an aircraft to ensure we knew everything there was to know about the aircraft. ( Actually BAE are doing the strip down)

My answer to Bob Ainsworth on the day was. it is a bit late now, I would have hoped you already knew all there was to know about this aircraft after all you say it's airworthy. His answer was they didn't want to miss anything.

[Jayand]

"My answer to Bob Ainsworth on the day was. it is a bit late now, I would have hoped you already knew all there was to know about this aircraft after all you say it's airworthy. His answer was they didn't want to miss anything."
Apart from the bloody point!!!!!!!
Have we really seen the end of that bloody idiot bouy 15? he managed to crawk back last time!!!!

[Squidlord]

nigegilb wrote:

it would appear that [CAS] has implemented many changes and he is working extremely hard to deal with many of the issues raised on this thread and others. It is not the style of Govt Depts to admit they are wrong. I wished I could go further here, but I can't, enough to say that MoD are worried about airworthiness issues and are acting.

(See first para. of post 1161.) Although mainly motivated by aviation safety issues, it goes wider than airworthiness (i.e., it's all MoD equipment safety).

I am not convinced that there is enough technical ability to deal with the challenge and it will of course require additional funding, another worry, but I am happy that they are responding.

I think the technical ability is available but I share Nigel's concerns over funding and would add willpower. This is not just a matter of changing a few procedures, doing a few more audits, etc. I think the problems within safety management within the MoD (possibly restricted to certain areas, e.g. aviation safety) are so engrained that changing them is going to take a hell of a lot of time, money, effort and discord. But the actions the MoD are taking are a necessary start so, personally, I am trying to be hopeful.





A long time ago, Distant Voice wrote:

What I can't find in 00-56 is guidance for when something is not safe (either broadly acceptable or tolerable and ALARP). Also, I can't find reference to say that the Safety Management System has a certain time to rectify the problem, just that if a risk is assessed outside the above criteria, it cannot be tolerated except in exceptional circumstances.

I don't think POSMS or other MoD documentation, e.g. JSPs, gives guidance either. However, it is certainly possible to argue that there is "time to rectify the problem" whilst maintaining the ALARP status of risks (also in post 1161 - this time in the last para., though not explained further there). I could explain more if anyone's sufficiently interested.





Back to nigegilb:

The 2nd line ["espoused by the MoD"] might be that airworthiness work concerned with ALARP is complete so Nimrod is airworthy. Again, anyone who read the Hickman transcripts would struggle to make sense of the argument.

I think this is almost certainly because Hickman was a poor witness (in respect of his claims about safety and ALARP). Also in post 1161, I wrote:

The concept of safety, as defined by MoD policy and regulation (see Def Stan 00-56, POSMS, etc.), depends crucially on how a system or equipment is used and maintained. It makes no sense to talk of a system or equipment being safe (or that the risks associated with that system or equipment are ALARP) without a context of use and maintenance.

and I gave the simple example:

Think of your own car. In some sense, it is "safe" if driven in accordance with the rules of the road and properly maintained. Now suppose you never maintain it or MoT it, and/or drive it at 100 mph through crowded playgrounds. Same car ... but is it safe now?

Since then, the following, very significant posts have been made by some of the best contributors to this discussion (in many cases, the posts are just the words of the posters and in others, very significant quotes are given from, e.g., the coroner's inquest, the MoD, etc.). In all the posts, claims are made about safety and ALARP. Virtually none (maybe none at all - haven't checked in the fullest detail) of those claims about safety and ALARP are made with reference to a context of use and maintenance. Consequently, those claims are just about meaningless!! No wonder everyone's so bloody confused!

1242, 1244, 1246, 1250-1252, 1254, 1256, 1259-1260, 1267, 1271-1272, 1291, 1303

Given:

• the context of use of the Nimrod has significantly changed more than once since the XV230 accident and is likely intended to change again significantly in the next few years
• and such changes have had and will have very significant effect on the safety of Nimrods,

if any reader of this thread wants to get anywhere with these discussions about ALARP and safety, they're going to have to pay attention to the fact that the context of use is vital. If they don't, they will remain confused, seeing contradictions where, likely, none exist.

And yes, it's true that the MoD are just about the worst offenders in this regard. The MoD don't seem to be that concerned with being explicit about the context of use and maintenance in their statements about safety and ALARP (as evidenced by Hickman's testimony to the inquest and other MoD statements on the safety of Nimrods). This is a major failing on their part that has led to a great deal of confusion both within and without the MoD (on this thread!).

If you doubt the vital importance of the context of use and maintenance:

1. go back to the posts listed above and find all the instances where people claim to have found contradictions over statements about ALARP and safety and see how many of those apparent contradictions would be nothing of the sort had the individual claims been caveated with references to *different* contexts of use and maintenance. And see how many of Hickman's confusing statements about ALARP and safety could be explained were he to have been careful in defining contexts of use and maintenance.

2. Look again at the definition of "safe" in POSMS (the most relevant source for this discussion - the definition in Def Stan 00-56, Issue 4 is, unfortunately, slightly different though not in the emphasised text below):

http://www.mod.uk/DefenceInternet/AboutDefence/CorporatePublications/DefenceEstateandEnvironmentPublications/ASEG/ProjectorientedSafetyManagementSystemposmsManual.htm

Risk has been demonstrated to have been reduced to a level that is broadly acceptable, or tolerable and ALARP, and relevant prescriptive safety requirements have been met, FOR A SYSTEM IN A GIVEN APPLICATION IN A GIVEN OPERATING ENVIRONMENT

The emphasised text (my emphasis) is the equivalent of the "context of use and maintenance" that I keep referring to. It's vital!

[Chugalug2]

Squidlord, as one of the many posters whose work you have quoted you say in reply to my call for an MAA:

The MoD is currently considering a separate MAA organisation but I doubt if they are seriously considering making it independent of the MoD. I don't know whether Chugalug2's claims hold water (no evidence is provided). Perhaps the idea of an independent MAA will be considered by Haddon-Cave's Nimrod Review:

I am sure you are quite correct in your assumption that the MOD are not considering an independent MAA. The words turkeys and Christmas spring to mind. However any other form of MAA would be unable to carry out its remit of ensuring Military Airworthiness and would thus be a waste of time and money.
You say I do not provide evidence for my claims. This isn't a Court of Law or even a Judicial Review. It’s a forum in which we express our points of view. If these are at variance with those of others they are rightly and swiftly challenged. You also say in post 1161:

I don't really understand "airworthiness". I know the definition in JSP 553 but it is vague and has no obvious connection with ALARP

This seems to be a common theme throughout this thread whereby generic terms such as Airworthiness appear alien (it is even confused with serviceability in some posts) and more specific ones preferred (such as ALARP). I realise that this is all part of the moving on since my day, but I still feel a slight unease. Airworthiness (I will not try to quote a definition, but it would be helpful if an up to date authoritative one could be posted) is the woods in which the trees such as ALARP exist. If we know each and every tree but are only vaguely aware of the woods, is that not a danger in itself? If there were anything to learn from this and similar threads it is that the Regulations are sound enough, it is their implementation that is at fault. Without an awareness of the culture that lies behind them, that implementation is prone to compromise. The name of that culture is Airworthiness. Time perhaps it was the subject of more scrutiny in itself before we go on to examine the likes of "acceptable" etc?

[nigegilb]

Chug, I got this reply, an opinion from an expert not so long ago.

In very simple terms, if MoD (or Government) contracted out Military Airworthiness Regulations to, say the CAA, the first thing CAA would do is ask "What is the design baseline for each aircraft?". MoD can't answer. Then "Resurrect the build standard so we can establish a contractual baseline". That needs huge investment and many many years. It could never get off the ground for most legacy aircraft. If CAA did accept a contract, there would be so many get out clauses necessary that it would be worthless. MoD would be so heavily liable, it would be a pointless exercise.
However, a good compromise would be to create a MAA for all emerging and future aircraft. If they acted quickly, that could encompass quite a lot, and in a few years the likes of Sea King, current Lynx, Tornado etc etc would slowly disappear. That would spread the cost pain while demonstrating something is being done.
I think this compromise would avoid MoD having to admit they have more or less ignored airworthiness for 20 years. While we'd like to hear them admit this, it's politically unacceptable and they'd be potentially tied up in litigation for decades. I think this is why they don't change the Chinook verdict. But, Nimrod is the thin end of the wedge.
Of course there is much more to consider, but the above is, I think, a good line to take which MoD may actually be thinking about now. It's an obvious option. I wouldn't be surprised if they didn't suddenly make an announcement on this.

[Chugalug2]

Nige, as you say an independent MAA must work. If it literally cannot work with legacy aircraft then they must be excluded from its remit and remain by implication unairworthy! What an indictment of the MOD and those charged with the implementation of military airworthiness regulations. What a betrayal of those who have to go on operating such types, and those NOK who have fought so tenaciously to ensure that the avoidable accidents that their loved ones died in should not be repeated. What is there now to prevent that? The MOD? The RAF higher command? I wouldn't buy one of Squidlord's used cars off of either one!

[nigegilb]

Chug I still find it astonishing that most people are willing to accept the word of a non-expert minister stating that Nimrod is now airworthy. OK he is only repeating the advice received by qualified people from within his organization. But hey, everyone remembers CAS reassuring the world about the safety of Nimrod to continue AAR in the aftermath of the midair explosion. Now look at the line MoD take on AAR.

It has been BANNED and it will never be allowed to resume. Airworthiness implementation has been so badly eroded I doubt the MoD have any clue how to construct a road map leading them back to where they were before the swingeing cuts were introduced in the 1990's.

BTW don't lose heart on this, things are astirring. Nuff said.