You raise an interesting point there, DV. Pressure testing a system to 50 psi that is known to surge to 80 psi would appear to be an oversight. Way above my pay grade, maybe Tucumseh will help you out there.

Your statement leads me to draw two conclusions (from a distance)

That the people at Kinloss are looking at either an AAR pipe failure, or No1 tank failing to shut off during AAR and developing a major leak.

You still need an ignition source. To those of us in the business, fuel leaks are common, and aviation fuel doesn't burn that easily. I can't imagine that the BoI will identify an ignition source.

I expect the BoI will be 30 pages long, but the only certainty is that -

'After AAR, a catastrophic fire in the bomb bay resulted in the loss of the aircraft'

I'm retiring from this thread to wait for the BoI

SPHLC

Sir Peter: Thank you for your input. Yes I understand your point about the limitations of ground testing, coupled with this is the fact that aircraft sit on the ground at +40 and refuel at -40, would hate to be a coupling seal under those conditions

DV

The point is and this will be of some comfort, the groundcrew are doing everything they can to test out this equipment. This is supposition but it does explain a few points. And we are not talking about a straight fuel leak here, but atomised fuel. (The other theory is hot air). But I agree, how is the BoI supposed to figure it out? Just get some bomb bay fire protection sorted, quick. And fit fuel tank protection for good measure.

"However, we had heard that the fire was at the starboard wing root area of the ac.

Now, there is a fuel pipe in that area which is used in AAR to refuel one of the internal fuselage tanks. Further, on inspection of another ac in theatre a small hole was found in the pipe. The pipe is welded to several brackets which are themselves attached to the supporting rib wall and the hole was close to one of the welds.

It is not uncommon for there to be pressure spikes during the refuelling process as refuel valves are closed elsewhere during the process. It is possible that repeated pressure spikes or repeated applications of normal pressure during either ground refuelling or AAR might have lead to the weakening of the weld and the subsequent hole. Atomised fuel could then escape into the space. What is missing, however, is an ignition source and that is a bit of a stumper.

If we assume that somehow ignition took place it is conceivable that the fire could then heat a fuel tank that is positioned in the wing root area, and this may have led to the explosion.

What is interesting to ponder is that the same airframes are generally being used for the Gulf theatre due to their fit. These few frames would be used in AAR more frequently than the other ac in the fleet. This argument might also be backed up by the fact that the fuel pipe hole was found in another Gulf ac in theatre."

I would just like to add that a whole year has gone by since I was given the above information. A whole year when crews have experienced huge fuel migrations, without any bomb bay fire or fuel tank protection. Absolutely no requests are in the system for the MR2 or MRA4.

"How can this possibly be called good risk management."

Edited for reasons that will become apparent.

BBC News request
 

Hello. I'm a researcher for BBC News. I've spoken to Danny Fyne and he's approved this post.

In anticipation of reporting the conclusions of the Board of Inquiry into the crash of XV230 for our main news outlets, we are keen to pick up on some of the posts about the Mk2 and MRA4 and to see if there are any recently serving or serving aircrew willing to talk to us.

We're also particularly interested in comments about the refurbishments being made to the MK4 and whether they are sufficient? If you have any relevant first hand experience or knowledge of the Mk2, RMk1 & MRA4 or have information and insight which we should be aware of, please get in touch by email or telephone.

Any correspondence will be entirely off the record and in strictest confidence. My contact details are
[email protected]. Or 07841 054936.

However, any comments posted on this thread will also be considered subject to verification.

Thanks very much.
Fiona Mackie

To all those with a blinding faith in the BoI and MOD see below the words of Rose Gentle:

http://news.bbc.co.uk/1/hi/scotland/...st/7082689.stm

To those who believe there couldn't be another 230 and that everything is being done to prevent it:

But hey those of you who have your eyes closed see nothing wrong, my advice is sit down before you open them!

Da4orce

My eyes are not closed but I will remain to wait the findings of the BOI.

Your constant lack of respect towards the majority of the families who have asked for restraint in the speculation, who have asked for the cease to media involvement and to give us some respect during our times of grief, I find utterly disgusting.

You sir, are a dildo

Thank you for you intellectual input Lab Queen, since I have not posted for the last 3 pages of this thread and it has continued without my input I'm not sure why you single me out for such abuse.

It is for your comments about having our eyes closed and advising us to sit down, you attempt to belittle those who wish to await the factual findings. Maybe it is not us who are blinkered, maybe we see much more than you give credit for

Sir Peter

Thank you for your faith in me (!) but it’s not my trade, so can’t even comment on the fuel pressure issue. I would just repeat observations made before.


It is quite common for MoD to introduce design changes by Service Engineered Mod. The original justification process underpinning SEMs has long since been overtaken by one factor – quick and cheap. But often in the rush for cheapness, proper testing and trials are ignored and maintainers are not provided with the wherewithal to verify any repairs to the mod. It is long standing policy not to buy spares to support aircraft mods and, as test equipment and tech pubs are dealt with at the same time via the same process, they often suffer a swell. This scenario will be instantly recognisable to any maintainer here, and the abuse of the SEM system is a major standing risk. (The same applies to UORs). They have their place.

Also noted elsewhere is cable chaffing being a common ignition source. When considering this in conjunction with tolerance build-up, maintainers will again know that the relative position of same cables/looms between tail numbers can vary enormously. From what I know of the Nimrod, with the mainplanes being essentially handmade and no two being identical, this tolerance build-up may be significant. I have also seen major defence contractors make the howler no 1st year apprentice should make – insert negative tolerances in cable/loom drawings. (Not suggesting this is the cause, just illustrating a point). This is a very difficult area to manage and record under the Configuration Control process. I know other aircraft where dimensional differences between production runs are known, and recorded as call-ups in the GA. This info is used to, where necessary and as far as possible, ensure no materiel is manufactured which cannot be fitted; but it’s not always possible. This of course is insignificant compared to MoD’s long standing practice of denying funding to routinely maintain configuration control, which breaches their own airworthiness regulations. This kind of contradiction disturbs me.

I mentioned this the other day, in response to Bingo Handjob. Did anyone read the report by the Select Committee on Public Accounts? CDP was asked to confirm Configuration Control would be maintained on a specific aircraft. (A very good leading question, and one should ask what prompted it. My guess is Mull of Kintyre). He said yes. What wasn’t said was that the same CDP also ruled that a project manager could be formally disciplined for refusing to proceed to contract when no provision was included for Configuration Control, or other components of airworthiness. OK, it was a few years ago, but various Ministers of State have consistently upheld his ruling. And been kind enough to confirm it under FoI. Now, that’s something that really disturbs me.

Lab Queen

You have no right to speak on behalf of the majority of families (of which I am a member of one and friend of others)

If you are disgusted by those families that are involved with the media including your own family (Panorama). It is very simple to be selective about what you watch on TV, listen to on the radio and the publications you read. With regard to rumours it is even easier not to log on to this type of website! There is far more to life than TV, radio, papers and the internet.

I do not wish to be involved with the media but understand and resepct those who do, it appears to me those involved want to get to the truth and to ensure the safety of the rest of our friends and family still flying Nimrods.

Redsquirrel83

My family were not involved with panorama and have not been involved with the media.

You may see from this thread alone that several family members, from different families have posted to ask for the speculation to end, and for the media involvement to end.

Yes we do want the truth, but as has been pointed out by other people here, this is a rumour network, what is said on here about the accident, can only be classed as rumour, and yet is enters the press and is written as if fact. It is the BOI which will give actual facts about what happened that day.

It is not a simple process of being selective what is viewed on television or read in the papers, when there are times it is splashed across all avenues.

It has also been stated that the speculation has proved fruitless, no changes have been made down to speculation alone, which does prove the point that it is only facts which may do this.

We all wish to know this will not happen again, but speculation, bringing that speculation into the media, whereby a lot of it has, afterwards, been found to be misleading, is not helpful in any respect.

RAF Nimrod puts out Mayday call after 'major fuel leak'
 

An RAF Nimrod flying over southern Afghanistan put out a Mayday call and made an emergency landing at Kandahar air base on Monday after crew found fuel pouring into the bomb bay.

The aircraft was in the middle of refuelling when the crew discovered what several sources described as "a major fuel leak" in the bomb bay. The pilot immediately declared an emergency and broke off refuelling.

It is a repeat of an incident in September last year, when an RAF Nimrod exploded over Kandahar province killing all 14 on board. The board of inquiry into that incident has yet to report but that Nimrod, tail number XV230, had just refuelled in mid-air and the board's initial findings blamed pressure from the air-to-air refuelling system for forcing a serious leak.

The Ministry of Defence said today that nobody on board had been hurt in the latest incident. Air-to-air refuelling had been suspended "as a precautionary measure" but the fleet had not been grounded.

http://www.timesonline.co.uk/tol/new...cle2826702.ece

:mad: Thank god they got back safe.

MR2 vs MRA4
 

I have prevented myself from posting on this thread for as long as possible but I feel I need to air a few issues that have been eating away at me for a while.

The MRA4 is not merely a refurbished MR2, it is a new aircraft, a fact that has been lost to a few in the MOD over the years. Reading some of these posts it appears that a few posters are making this mistake too. To complain that no changes have been made to the MRA4 design due to perceived flaws with the MR2 design is fundamentally wrong. It's similar to complaining that no changes have been made to the Tristar design following a report into the MR2 system - it's irrelevant as they are 2 different aircraft; as for MRA4 and MR2.

The core design for the MRA4 was frozen years ago and the Key User Requirements were defined and contracted to. These did not include bomb bay and fuel tank fire suppression. To insist that the MOD is negligent in not incorporating these changes into the MRA4 design at this stage are lacking any appreciation of the work involved to get these changes incorporated. My opinion (and just that) is that it would add at least a year onto the project if not more. What mitigation is there to keep flying the MR2s for extra years compared to the benefit of bomb bay fire fuel tank fire suppression? The probability of these happening have already been reduced to as low as reasonably practicable and so should not happen within the lifetime of the aircraft. Other key areas of the design result in a catastrophic failure of the aircraft with possible loss of life however these, through engineering analysis and industry best practice, have also been reduced to as low as reasonably practicable withous further engineering. As stated in previous posts, to reduce the risks to nothing would prevent flying, if not life in general, from taking place at all.

What I am trying to convey is leave the MRA4 out of this debate. If you want to question the MOD policy on heavy aircraft equipment and upgrade procurement then start a new thread.

Da4orce: In your reference to the 255 SFS you are linking together two parts of the report, as though they appear in the same paragraph. They do not.

I have already asked the question regarding IPT knowing about it in my posts around #928. I got some sharp answers back.

DV

Noted and post ammended accordingly.

While I note LabQueen et al's concerns over grieving - I know how personal a process it is - I would be wary of the mantra that the BOI is going to establish the facts about what happened on the day. Without access to all the bits of the aircraft, IMHO it is highly unlikely that they will positively identify the final cause of the accident. However, what a number of others here are talking about isn't the last few moments, but the last months and years, and the events that may have built up to the accident.

5206

Tonight's Timesonline;

RAF Nimrod puts out Mayday call after 'major fuel leak'

We could be issuing condolences tonight for another crew who could have been killed in the same place. I believe 12 months is worth the price to pay to provide proper protection for Nimrod crews.

MRA4 design frozen or otherwise?

"Nige,
'a double skin system'?

It's never too late to design whatever, However, the MRA4 design was frozen as of last December. Any changes will only be at the customers request(& funding). Realistically it won't happen given the current situation re funding and bearing in mind there is no requirement to qualify the AAR system at this time.

...The AAR system on MRA4 is the retained MR2 system. That means what the MR2 has, MRA4 will have also. That said, there are some differences, mainly where that fuel enters tanks in the Bomb Bay.

The AAR system will not be qualified on delivery. It has to be available ready to use at short notice.

The system does carry fuel though, and it is pressurised (& yes we have had the odd leak during ground refuel).....As I said, there is no design for foam in tanks (neither Flight Deck Armour funnily enough). It will only go on MRA4 at the request of the customer.


..........I can confirm that there is no intention to fit foam to MRA4 fuel tanks (unless the 'customer' requests (& comes up with the funding for) it...).

The aircraft is designed to a customer specification.

The specification doesn't call for foam in tanks..........

......As to the fire in the starboard wing root...............
Sorry on that one.... all I can say is that there was an uncontrolable fire reported in the Bomb Bay, and......... In my opinion... , any such fire may have involved Tank7 (the closest fuel tank to the rear of the Bomb Bay which would explain a 'wing' explosion). A fire involving tank 5 & 6 would have surely led to a 'tail' explosion....

Footnote, Herc Ks are a bit tired and close to OSD but every single one now has foam in the fuel tanks. If you are so concerned about the state of MR2 why aren't you calling for bomb bay fire protection and fuel tank protection in MR2?

nigegilb: Well said. Sorry MoD and IPT, three strikes and you are out.
Who is now prepared to sign-off an a/c, according to any new IPT directive, and say "this is safe to fly". And what captain is prepared to accept any aircraft cleared under a new IPT directive.

Come on guys, now is the time to say "I don't sign" and "I don't fly"


DV

Nige,

I had no intention of patronising people and if that is how it came across then I apologise. However, your sources are correct and incorrect. There was an aspiration to freeze the MRA4 design late last year (PA X) and any changes defined as delta PA X to be frozen, as you say, in December. However, this has not stopped the changes. The current roll control circuit has yet to be fully defined to alleviate current handling quality issues and will probably not be until the end of the year.

To state that the AAR system is the same as MR2 is too simplistic. Yes the probe is retained but the rest of the AAR SOVs, fuel system, pumps etc which intrinsically control the fuel flow and distribution (USMS computers control valve sequencing) are so far removed from MR2 as to not even try to compare them. It is how the system copes to fuel flow fluctuations and what it does with the fuel that merits investigation and therefore to compare MR2 and MRA4 AAR systems as one is flawed.

'The AAR system will not be qualified on delivery. It has to be available ready to use at short notice.' - The AAR will not be qualified, period. Not only because the system will not be tested, but because the aircraft engines will not be cleared for wake penetration behind large aircraft. It will have no evidence to support RTS, therefore will not be cleared.

Flight deck armour has always been an aspiration but there is no funding. MR2 armour was fitted under a UOR in short order and this does not preclude the same happening for MRA4 following ISD (2010). It is easier to get funding in the current climate for a UOR post ISD than to contract BAe to change the specification.

My reference to project timeline extensions was poor, what I am trying to point out is how long will people want to wait for these modifications (the list could be endless) whilst the MR2 is forced to still fly as there is still an operational requirement to fulfil, that is all.

WRONG !
WRONG AGAIN ! The JSP553 is a mess and the people responsible for it are largely incompetent. Def Stan 00-56 has NEVER sought to lay down hard and fast levels of safety, NEVER ! Read the standard, both issue 2 and issue 4, if you still don't understand drop me a PM, and I will explain it for you.

Agree wholeheartedly with Chug on this. r supwoods, please tell me you have nothing and have never had anything to do with the regulation of airworthiness ?

MOA

Given your obvious lack of understanding of safety engineering, I suggest you prevent yourself from posting for a little while longer.

I sympathise with family and friends who are not happy with the specualtion, it is not helped by those who post whilst knowing so little. Unfortunately many of those who know and understand so little are often the people making the decisions. Try to understand the real underlying theme, read the posts of Tucumseh, Chugalug, Safeware, The Swinging Monkey, Nigegilb and myself, we are people who understand the system and where it is failing. Military Aviation Regualtion is failing, it is a broken system. For those who have read and studied major accident reports such as Herald of Free Enterprise, Piper Alpha, Clapham Rail Crash, Challenger and many more, the organisational failings reported are shockingly similar.

Safety_Helmut