OMS, well done for doing the full whack.
I have no concept of the workings of an EA/PTL except (2010-2014) those I dealt with who didn't very much in the way of Maintenance Programme updates (Maintenance Schedule updates) apart from reacting to emergent issues warranting their attention.

I was a rigga from 75-99 and I've worked in airline and MRO quality and continued airworthinesss management since then. As an "aviation" Quality Manager I never touch ISO9001 (QMS is not a legal requirement) so I concentrate on regulations and practices to cut costs in a legal and risk averse fashion.

I only met two that were career minded in the sense that you felt inconvenient truths were just being kept close hold, and one definitely wasn't an idiot.

The others weren't career minded idiots, they were good people. They wanted and needed to get on, but falling on your sword, even at EA level, is frankly unlikely to cause more than a small stir as a new EA is found. It's more nuanced. If they don't do it somebody else will. They understood the issues but found themselves in an impossible situation inside an organisation with a deeply flawed culture where staffwork and a good thesaurus were the answer to all problems (The rest of the world does it another way, but why let that concern the path were on). The nub of the problem didn't really lie with the EA anyway, it lay with the customer who knew that they had to fly the things. Many problems were of the customers own making (how many E3's in the green today, what did we tell the Minister last year) and required an ever deeper hole to be dug, some were frankly down to the awful politics of everything at that level, and the fact that the Sun is equally happy to write about things not being pushed far enough (Aircraft grounded in RAF Chaos, there's a war on don't-ya-know) as they are when disaster strikes.

In the end, I just felt that it was 'Yes Minister's writ large, and everybody actually relaxed when the truth was told and they knew where they were.


Unfortunately, that was rarely where the MAA wanted them to be, but that's just another side of the same coin that's significantly unbalanced in weighing resources against tasks against aspirations.

It's quite possible that there was genuinely somebody at the top who was longing to hear the problem and truly accepted that termination was an option. I never had the impression that anybody at 1* level was keen to test the hypothesis, which gives those at the top a perfect get-out (Yes your honour, of course I would have stopped straight away, had I only known). Yeah, right.

For all people can hand-wring about RA's, EA's and DH's the reality from my viewpoint was that they were window dressing to the root cause, which was the naked emperor that is the cause of most good staffwork in non-operational matters.

I didn't envy the DH.

This entire 'construct' is, I believe, flawed for a number of reasons. Today's 'Duty Holders' are unlikely to understand or have experienced how to actually deliver and maintain airworthiness. They may know small bits of it, but are more likely to have an inkling about Fitness for Purpose. You can see this in the MAA's regulatory set, which to a large degree concentrates on FFP to the exclusion of the pre-requisites.

The last time I spoke to a senior officer in the MAA, he didn't understand the difference; which was also evident at the C-130 XV179 Inquest in 2008, when the IPTL simply hadn't a clue about his primary role. He didn't say 'of course I would have stopped straight away, had I only known'. He simply denied that he had anything to do with it; and even if he knew what to do, he wasn't allowed to. The families were left wondering who the hell was responsible. The implication was it was all the fault of some junior officer out in Iraq who, somehow, was meant to go and buy some Explosion Suppressant Foam and stuff it in fuel tanks. That's not criticism of either officer. Nothing in their background prepared them for their roles. Nothing has changed.

Engineering Authorities (by which I mean SNCOs and junior officers) are more likely to understand quite a lot about all three areas. I always found the EAs in all three Services superb. But, reader8, you are right in saying very few would speak out, especially when (by definition) you're complaining about a VSO. Slightly easier for civilians, but MoD personnel policy has effectively got rid of any experience.

Yup, agree. One Pprune post can't characterise a whole system that's flawed from the guy on the 18 month ground tour deciding what to buy onwards. Plus the relative anonymity allows one to discharge both barrels.

I would say that it should be the job of the staff to educate the VSO. It's the job of the VSO to take the time to listen and understand when they are paid handsomely for the responsibility they hold. Too many complain about "too much detail" or "this is confusing" to give me a great deal of sympathy (although to be fair to them, it's often their staff laying that foundation for whatever agenda they may or may not have understood from the VSO, as I said, relentless politicians). These two phrases are dispatched by the VSO with a well practiced body language which either says 'tell me more' or 'STFU'. When it's STFU time, maybe they don't understand, maybe they don't want to. I think that if you can't tell the difference you still have problems. There are not many aircraft types and plenty of senior officers to go around.

I did occasionally see a DH simply listen to opposing viewpoints, allow both sides to frankly express views and then give homework and accept risk. It shouldn't come to that, but at given the, as you say, FFP nature of the whole thing it often did. Unfortunately, that behaviour was the exception not the rule.

Of course, depending on the structure of the acquisition the DH may not be able to do much anyway. Take P8 or F35, if there's something the Brits don't like, surely tough if there's a CBA to be done for a global fleet.

At least the front line knows, by-and-large, how to actually operate the thing. Civil aviation breeds experts, we generally don't. People can become so, but when they do the service can't take advantage of that

DE&S are supposed to be the answer, they're not. Again, rarely personal, just a system that doesn't work right.

If it all seams like a bit of a perverse characature, that's because it can be! Safety in terms of airworthiness is best achieved through compliance with recognised practice at the lowest level possible. When that doesn't happen, regardless of whether the problem is in materials used, designs embodied or redundancy provided, things go wrong answering the only question there is "but what does that mean".

This thread has been enthralling.

It seems that most posters (since the judgement anyway) are in broad agreement over the myriad causes of this tragic incident. We all understand there is/was 'something rotten in the state of Denmark', but what can be done about it? I really still cannot see the EA equivalents of today (SNCOs and Junior desk Officers) getting much joy from taking their concerns to their VSOs. I would love to be wrong.

IMHO, It is particularly poignant that the family of those poor people killed in the Grand Canyon helicopter crash recently are taking both the owners and the aircraft manufacturers to court over their failure to fit (if that's the right word) fire suppression to the fuel systems. I doubt that those responsible for that one will be able to 'hide' in this civil case.

So what, in your opinions, is an achievable 'way ahead' for UK Military Aviation, such that is left of it?

Answers in simple terms please - and not too many abbreviations etc ....

OMS,

Just as a small aside - it is the fitting of a 'plastic' fuel tank that is believed to be the problem in the Grand Canyon accident: the same one fitted to all the DHFS squirrels.

And I agree, the thread makes fascinating (or should that be frightening) reading, particularly those inputs from Tuc, Chug 2 and Rigga, but also beggars the question 'why did MB roll over?' Or have I missed something

I think some of the passengers survived the initial impact but suffered severe burns before or during egress and passed away later. It was a ticker tape headline on Sky meejah yesterday. Fuel suppressant issues feature heavily in the airworthiness discussions earlier in this thread.

thanks I take your point on the plastic tank, however fuel suppressant discussions (and the lack of airworthiness action to implement protection) feature heavily in many of the posts in this thread. As for why MB rolled over? A very good question which also deserves an answer.

The MAA paid quite a lot of attention to adapting the civil regs to the UK military context but I feel they missed a fundamental point: in the civil system, the obligations are placed on those with the technical competence to make the right judgments. You have to use these people wherever they are to be found (irrespective of rank or organisation). Tuc has often drawn our attention to the CS process for gaining competence. While I agree wholeheartedly with his views, I doubt whether that process can be recreated in the medium term.

Just my opinion. Companies exist to deliver commercial success. Maybe MBA and their insurers decided that rolling over was the most effective way to return to commercial success?

EAP

I for one am a great believer in keep it simple, I always have believed that burdensome legislation is not and never has been the way to go forward, It hampers those trying to achieve airworthiness whilst no matter how much paperwork you produce, those that failed to carry out such work previously are never going to do so simply because you have produced more rules.

In an ironic twist, EASA in their quest to make light maintenance "simpler" (read.. push responsibility off their shoulders and onto others) have pushed it on individuals to produce their own maintenance programmes for their aircraft, this has resulted in each individual aircraft of each individual type having a different maintenance programme, where as before you operated to a generic one size fits all that covered the basics, thus ensuring safety and a minimum standard. Now it is in my eyes cost driven.

To be clear, each airframe has an EA, a Senior Officer who holds an LOA to allow him or her to act as such. These aren't SNCO or JO failures. The EA role is still staffed by somebody who should be SQEP to act as such.

Sorry, I meant the guys at desk level who did the donkey work back in the day. I accept that the entire dept was the "EA (Engineering Authority)" IIRC ours was headed up by a SO1 (Wg Cdr) level who reported to the DD (a GC) by the time I left the first EA I was in, the Wg Cdr was in fact a Supply Branch officer. However, I recall going for guidance to one of my earlier Wg Cdrs (this time an Engineer) with a particularly 'difficult' issue, his response was, and I quote "oh, er, just keep all the balls in the air for a while, I am posted next month"

Clearly not SNCO/JO failures

The problem was never the lack of regulations, they more than ensured that UK Military Airworthiness was fully functional and effective, provided they were implemented. And so they were, until the RAF equivalents of Pol Pot ordered that they be suborned, ie signed off as complied with but not implemented. Those trained and experienced engineers whose work it was to provide for airworthiness were now immediately faced with a moral dilemma, to defy what were clearly illegal orders or comply, with all that would entail. Those who complied ensured that there was an immediate break in the continuous process of audit that is the cornerstone of airworthiness. Without it even the most simple aircraft are rendered unairworthy and so the ACO gliders were grounded... sorry paused in consequence, albeit only eventually. Those who defied the order were hounded, persecuted, appealed, only then to have it confirmed by ministers that the orders were proper and that defying them was an offence. Eventually those square pegs were replaced by compliant inexperienced untrained non-engineers. The corporate knowledge was lost, the regulations pulped, and year zero heralded the infamous H-C Golden Period.

No amount of reinventing the wheel will avoid a repeat of this scandal happening again. You may well ask why RAF VSOs should want to subvert the airworthiness of their own aircraft. Of course, they did not. All they wanted was to release the historically ring fenced Air Safety monies to plug a gaping hole in the supply budgets, not caused by government cuts but by the ineptitude of RAF VSOs. The problem was not why but how, and it was all too easy as they outranked anyone who might seek to stop them, or reveal what had happened, or that certain resultant fatal accidents were airworthiness related. In short they did what they did because they could. Civilian Operators would no doubt do the same given half a chance, so they are denied it by having an independent regulator and investigator.

OMS, you ask what is to be done? I say do the same as the civilians. Nothing less than an independent regulator and investigator will suffice, lest history repeats itself (it oftimes does you know).

EAP86

Or long term, as it requires will. There is no longer a natural recruitment ground, as our workshops have been privatised. This contributes to the fact that most CS 'engineer' recruits don't realise they're skipping five grades. That's a lot of learning and experience missing. While they get on with their job, neither they nor their bosses understand what is NOT being done.

reader8

Has this term ever been defined by MoD? I know it defined 'inexperience' in the context of engineering programme manager (which, to a civilian, is something you do after EA, ILS Manager, Requirements Manager - or used to be!). 'Qualified' to, say, CEng, wouldn't have helped Flt Lt Cunningham. One thing that would have saved him was someone who'd listened to his first lecture on threaded fasteners and how to fit them, could read the regulations he was given a personal copy of, and passed a practical trade test.

When I joined SM65 (WPNS) sometime after you. My LOA was issued by the GpCapt. The WgCdr Stacker was out of the loop on all things Engineering. We tended to leave him sat in the corner orchestrating his release or managing his stocks and shares. The WOs who worked for me did not have LOAs.

IIRC, LsOA (letters of authority???) started to appear in the very early 90s as the 'EA' Morfed into a MDG, and then into a SA and IPT. My direct boss at the time was an Electronics S/L on retention. Excellent chap, very knowledgeable and eager to learn about my specialisation. On the other side of the office was a very capable and bright F/L. These two guys were very good (not all their predecessors had been) but I'm sure they were both frustrated as I was by the salami slicing that was going on. As you so rightly pointed out, WOs were never given 'delegated authority' and the responsibility for rubber and leatherware was delegated to them. So I guess they must have received their delegated LsOA shortly after I left but before SM65 moved up to Wyton.

I remember being surprised that final responsibility was being driven down to the level it was. It didn't make a lot of sense unless abrogation of responsibility on high was the aim all along. But what did I know?

I think that is rather unfair, If there is nothing to say the shackle should not be tightened down then the natural assumption would probably be to tighten it. The problem lies not with the person tightening it, but with the flawed design that allows it to happen in the first place.. I see poorly designed items day in day out and some actually assembled incorrectly by the manufacturers, because the design and the information are not there to prevent it.

Nutloose,

I'm really sorry, but I have to refer you back to my post 463 on this thread.

The RAFAT's arrangements for servicing ejection seats was, in my honest view, a shambles. No proper training, lack of experience, documented malpractices, all found by the SI. Add on to that a culture of abbreviated timescales, 'bespoke' routines, and an RTI that, again in my own view, should never have been issued, all combined to put this pilot in danger's way.

The over tightening of the shackle (and since when has cutting new threads into a bolt been 'accepted engineering practice'?) was just another link in the accident chain. Despite what I've said, I would not have harshly criticised the man who turned the spanner that day. I'd have started with his supervising NCOs, moved up the chain to the EngOs, asked the SEngO why his unit was being so cavalier with ejection seats, then asked the OC Eng what his safety and QA cell was doing to make sure that ejection seats (which are hazardous by their very nature) were being properly serviced.

And by the way, I wouldn't have asked very nicely.

The tragedy here is that, as Tuc as pointed out so many times, the main problem here wasn't lack of regs, or incomplete instructions. The main problem was a comprehensive failure to apply well known and extant regulations to control, manage and implement safe servicing of an ejection seat. And that failure took place within DE&S and the RAF.

Could the shackle design have been improved? Possibly. Were there shortcomings in the documentation? Probably. But if you give poorly trained, inexperienced personnel the responsibility for frequently disassembling and reassembling a safety critical item on an ejection seat, they you are creating a far bigger risk that MB ever did.

Best regards as ever to all those working so hard to keep our people safe,

Engines

I didn't realise he had rethreaded the bolt.

It is worth reminding ourselves that when Martin-Baker issued SIL704 after the accident, part of the reason was they were under new instruction from MoD to remove the assumption that RAF engineers would be adequately trained.

Hitherto, they had been instructed to assume a certain degree of training that would, for example, ensure maintainers didn't cut new thread and knew that the Drogue Shackle had to be free to move. The RAF Director of Flight Safety warned the Chief Engineer and ACAS about this very problem in 1992. That, maintainers were being held 'hostage to fortune'.

Remind me never to fly in a service aircraft ever again. That is frightening in the extreme. Looking at the current course lengths they are under half the length mine was.

Talk about a worrying situation, no wonder crews are leaving in droves.

So, I just looked up the definition of SQEP in today's MOD (MAA) MAA02: Military Aviation Authority Master Glossary Issue 6.1 :

Term: Suitably Qualified and Experienced Person
Abbreviation: SQEP
Definition: Intentionally Blank

Tucumseh:

SQEP requirements are littered throughout the RA 1000 regulations, depending on post, some more specific posts have them listed in a table, for example RA1003(1) & 1022(1) also RA 4945 has requirements for post but not utilising the descriptor SQEP:

https://www.gov.uk/government/public...egulations-gen

https://www.gov.uk/government/upload...45_Issue_2.pdf

I think you might find the courses are even shorter than the timescales would suggest. There's a lot more team building and adventure training than in the old days. That, and all the fluffy stuff, eats into the time to learn a trade.

Engines,

Spot on!

Regardless of all other actions, despite all the failures that caused the Ejection Seat to be activated; Flt Lt Cunningham should have drifted to earth on his parachute - surprised, but unharmed.

Regards
MM

I suspect not but I always thought it was not fully understood by many in the MAA. The nuclear industry use it extensively and its far more than just a term meaning 'competent'. There's a generic definition here https://en.wikipedia.org/wiki/SQEP but I think it misses the full scope of the nuclear usage.

EAP

I said re-thread because cutting a new thread can alter the dimension of the original bolt thread which you wouldn't want as it can effect the nuts ability to lock and weakens the bolt, as indeed lengthening the thread does, but hey ho, you can get none split dies that are designed to clean up damaged or bruised threads as in re-threading while not effecting the dimensions and can also be used to cut new thread..

and example of

https://www.grainger.com/product/CLE...xed-Die-20X681




..

BGG

I apologise if I wasn't clear. I don't agree with the definition of inexperience I mentioned. (Only having managed - not just worked on - and delivered 125 projects to time, cost and performance). It was and remains ludicrous, and I'd like to think most areas of DE&S don't apply it. Nevertheless, it was a formal policy, was applied, and is still cited. I mention this because I know the local Abbeywood MP/Minister once asked Min(AF) how widely this was applied and how many staff met the criteria, but MoD wouldn't reply.

I feel it is important to define SQEP for the purposes of airworthiness delegation, and technical and financial approval delegation. (All can only be given to engineers). Again, there are mixed messages from MoD/MAA. Correctly, it requires a degree of experience and qualifications, but in parallel continues to support those who self-delegated all three delegations - leading directly to many of the deaths discussed here.

I think honesty and integrity are equally important. One can be experienced and qualified, but a fraud and incompetent. Again, see the same deaths. We're not talking about scores of people. The same names crop up in most cases.

So, I think we agree. I don't like the term as it perpetuates the policy of dumbing down.

Regarding the pubs. Many are provided in the form of 'handouts' during training and, yes, you are right, they are not maintained. (As a matter of policy, so few are). But in this context (XX177) I'm talking about basic engineering that hasn't really changed for centuries. The AP that tells you one thread showing, not the 1.5 mentioned by MoD and HSE. (Apply that, and Sean Cunningham would be alive).

MoD has created a problem for itself by continually re-inventing the wheel. We lost our specialist Technical Authors (used to be around 600) and we now have contradictory regulations (e.g. 1.5 threads). Also, if the good book says to use a new stiffnut when loss of torque could lead to the loss of the aircraft, you really shouldn't need to spell out that this also applies to where loss of life could result, but the aircraft survive (e.g. this ejection). Note: stiffnut, not locknut, the term used by the SI. It's important to understand the difference when lives are at stake. And now that I've said this on MoD's Corporate Knowledge website, there will be a frantic re-assessment of said book and in a year's time a quiet amendment. As ever.

But, upon my first appointment as a Technical Agency (as you say, a new role, and requiring higher delegation) I was handed my personal copy of the two-volume Def Stan that anyone with airworthiness delegation should know backwards, that then sat on my desks for the rest of my career. If implemented, Sean Cunningham would be alive. (Just one of the layered defences in depth that broke down, long before he entered the aircraft). They were maintained, and our registry (sorry, showing my age) would come round and update it at each amendment. This standard was finally withdrawn in 2015, although staff had been told to stop using it many years before. It has never been replaced - D/Stan tried to update it many times, but weren't permitted. But the wise will still use it and, in fact, it still forms the basis of the Infantry's flagship programme whose aim is to reduce casualties. A noble aim, and perhaps the MAA should wander down and ask for an updated copy. Because, plainly, none of them have read it, never mind had to implement it.

Regarding the term SQEP when I was on the HEART team in 1997, the management epithet most popular at the time was 'tainted by experience'.
I found this a very curious way to do business

AA62

Yes, an oft repeated term at that time. It arose from CDPs' policy the previous year, that he did not want engineering project managers managing engineering projects. He announced 600 job cuts, just after everyone had moved from London. He was hated, and everyone I know had a little smile when Haddon-Cave dug a hole and shoved him in.

His problem was that the policy I mentioned earlier, new recruits skipping 5 grades, meant a huge disparity between staff at the same grade; so he chose to dumb down to avoid embarrassment. He should have been demanding that all staff satisfy grade minima. (Today, I'd say a mere handful in DE&S do). For example, I had two engineers of the same grade in one of my teams in 1997. One had airworthiness delegation and managed work that in other parts of MoD attracted sizeable teams. (He's still in, and one of the few). The other was minutes secy to a minor meeting, and entered data in a database. The latter was not to blame in any way, and in time became useful - but in a very narrow field, meaning he didn't meet minima. But the other was bored out of his skull, because he knew he was doing work beneath (what he considered, correctly) his paygrade. Equally, he was annoyed because the pay structure at the time favoured the inexperienced. This wasn't easy to manage, not least because Servicemen looked on aghast, as their system tends to avoid such disparity. Both OR and front line were given contact details if they had queries on any given subject, but all naturally deviated to the guy who knew how to solve the problem, even if not his job.

From the Nuclear SQEP description you have this:

Within the MAA competencies are within RA 1002:

https://www.gov.uk/government/public...petent-persons

However I think the point being made is there may be some lower down that are considered SQEP/competent and fulfil the criteria laid down, it is some of the management, both military and civilian, who don't necessarily hold that same competency or knowledge of the subject matter required of the post they hold, 'jobs for the boys' springs to mind, and are averse to being 'shown up' by their more capable subordinates, so ignore/suborn/prevaricate/hide information to cover their backsides when things go wrong, these are the ones who are at the heart of the issue.

To fill gapped posts some incumbents do not always fill the regulated requirements of experience and competency for that post, so end up not fulfilling the due diligence for the task, totally innocently in most cases, which would appear to suit the management style described above.

As has been said before, in cases like this the Accountable Manager/Duty Holder is where the buck stops and when it goes wrong they should be standing in the court to explain why it went wrong under their watch, don't see that often with regard the military to date, so these threads will no doubt continue unless they sort themselves out.

The trouble here is overlap, the RAF and the UK always has had a standard of 1 1/2 threads showing, remember, go back 50 years and we were a, if not the leading supplier of aircraft to the World, and the British standard was 1 1/2 threads.
The problem comes when the US started to dominate the industry and their 1 thread standard came into play, the likes of Martin Baker as a global player will have produced their goods to fit the standards of what must be their largest market. The RAF are then in a position of do you teach the 1 thread or 1 1/2 thread standard and bearing in mind that up until lately some aircraft still in service would be using the stricter tolerances, then surely that is the one to teach ( or both), if a bolt is to be tightened to 1 1/2 threads showing but is tightened to the lower figure then the potential is there for a bolt to be undertorqued.. So I can totally understand why accidents like this happen.

A stiffnut is a lock nut, they are one and the same thing, just different terminology, similarly a cotterpin is the same as a splitpin... push bikes apart.

While in the RAF I was taught and still adhere to the principal to replace all used stiffnuts, that was not always the case civilian wise as you could check it still retained a rundown torque.

note.

Advantages of the all metal lock nut are heat and wear resistance. Military and aircraft standards allow this particular style of locknut to be reused up to 15 times, given that the nut will continue to provide some minimum specified prevailing torque (United States' Military Standard 'Mil Std' MIL-N-25027).

http://mgaguru.com/mgtech/restore/rt104d.htm

My trade training notes. AP3279, AL7, Feb 1970. Para 30 is of course qualified elsewhere by the instructions when to use a new stiffnut (see previous post). A locknut is different from a stiffnut, although commonly used as a generic term. Often the difference is unimportant. Here, it is. (The one at bottom right is used in the seat).

I agree with your point that the problem is inconsistency across training and pubs. My point is that anyone using the same training I had would have followed this and the shackle would have been free to move. And the evidence, revealed in the judge's remarks, confirmed maintainers at other RAF stations stated one thread.

http://i214.photobucket.com/albums/c...psu3mwlemh.jpg


http://i214.photobucket.com/albums/c...psbqprlybp.jpg

Sorry, I should perhaps just clarify matters by saying all this is academic as far as the court case is concerned. The instructions issued by Martin-Baker to customers in the 1960s/70s/80s were:

‘Tighten nut until contact is made with Drogue Shackle. Do not torque. Verify that clearance exists between Drogue Shackle and the Scissor Assembly, and that the shackle can be freely rotated on the Scissor Assembly’.

Had this been followed, would Flt Lt Cunningham be alive? It may very well be that M-B didn't provide the warning in 1990, which was the basic of the HSE's sole charge. But very clearly they understood the issues and included warnings and cautions in their manuals. Their difficulty came when different customers wanted this expressed in different ways. So, just because the HSE said five other users were told in 1990, that doesn't mean MoD wasn't told in slightly different words that reflected its regs and training of the day.

RA 4266 refers to the use of self locking nuts, but as in the case of a lot of RA's it referes to the MAP-01 Chapter 6.15:

https://www.gov.uk/government/upload...tial_Issue.pdf

https://www.gov.uk/government/upload...ablemap-01.pdf

Extract from Chapter 6.15:

Finger tight. Which hand? I'm right-handed but arthritis means my grip between thumb and forefinger is weaker. (This has many disadvantages). I do remember 'finger tight', for example when loosely assembling something so it doesn't fall apart, having partially dismantled it to gain access to another area. In any case, try tightening a philidas stiffnut finger tight. There'd be no threads protruding. The end of the bolt would be half way down inside the nut. Even 'finger tight plus half a turn', which is taught in some applications, wouldn't be enough. If by some chance you could overcome residual torque with your fingers, then the nut is scrap anyway.

But as I said, simply not applicable to a safety critical part that must be free to move. This all needs rewording.

What document does a maintainer have when working at the aircraft? Not RA4266. Nor Def Stan 00-970, as claimed by MoD & HSE. He has the AP (not written by M-B), his trade training (whatever that may be), common sense and engineering judgement.

Edited to add. After the accident, M-B issued SIL704, which said 'flush', not one or 1.5 thread pitches. As MoD (specifically the Service Inquiry/MAA according to the evidence) required this, why has RA4266 not been updated? Is this just applicable to Mk10B seats? To the RAF only? To all stiffnut applications? As the CAA promulgated this SIL, the world and his dog must now be thoroughly confused.