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Flt. Lt. Sean Cunningham inquest

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Flt. Lt. Sean Cunningham inquest

Old 1st Feb 2014, 08:45
  #321 (permalink)  
 
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Originally Posted by dctyke
Zulu 10: If flexibility really is the key to air power, then you have to understand that it works both ways. ‘He who never made a mistake never made anything’ as the saying goes, the corollary of which is that if you want something made, then as a consequence it must be accepted that sometimes mistakes will occur.

Is it a 'mistake' to not use a shouldered bolt (fitted up to and including Mk9 and Mk 12 seats) that cannot be over tightened and use one that can. If a mod does indeed come out that has a shouldered bolt I would be asking why not in the 1st place.
I’m struggling to understand what you’re asking. Are you suggesting that the design which did not utilise a suitable shoulder bolt was a consequence of:

1. Pure (innocent) incompetence on the part of the designer, coupled with a lack of oversight by more experienced staff, or;

2. A review which noticed the potential for failure, but quietly and cognisantly ignored that matter, or;

3. A desire to save a few pennies in production by using cheaper part, or;

4. A belief by the equipment designer that an appropriate torque figure would be quoted in the accompanying servicing Tech Order, and a suitable torque wrench would be supplied to those requiring to adjust said fastener?

I do not know and cannot second guess it. Neither, I respectfully suggest, can you.

Are they all mistakes? Possibly. Are they all "honest mistakes"? No.

But to use the defence in depth principle, a good review process should have captured the first three and would have noticed the potential for number 4 to result in problems (i.e. Tech Pubs ignored, torque wrench out of cal etc) and therefore added a second defence mechanism i.e. a shoulder bolt.

You also seem to be suggesting that every design should be right first time. You’re a creationist I assume?
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Old 1st Feb 2014, 08:56
  #322 (permalink)  
 
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Originally Posted by tucumseh
Zulu

I must admit I didn't think of myself as a "poor sod", I rather enjoyed the job! I had good teachers.


I agree with the issue of nuances. But when signing off the work (a delegation granted only to engineers, my complaint being non-engineers are now allowed to self-delegate) you are signing to say the work has been carried out in accordance with the contracted specification. The MoD engineer is, uniquely, allowed (required) to exercise engineering judgement and defer issues, but only in exceptional circumstances. A typical example would be interface parameters not yet established from a parallel development. But, the good book says;

A Critical Design Review (CDR) is defined as a review to determine if the detailed system design meets the performance and engineering requirements (including safety) of development specifications. During CDR, the MoD must ensure that all design areas are adequately examined, that design weaknesses are identified, and that solutions for design-related problems are available. The MoD must use the results of the CDR to assess the readiness of the system to progress to the next acquisition phase. The design reviews and associated testing of design features let the MoD review the complete system design and evaluate its capability to satisfy total mission requirements, safely. The CDR should be effective and not rely on later production efforts to resolve design deficiencies.




Ever so slightly ambiguous, but it needs to be to allow deferments. But what it doesn't allow is a false declaration that the design is safe, knowing it is not!
Now you've opened another can of worms:
In my experience of dealing with MOD: the "contractual specifications" including the technical content, and the "the performance and engineering requirements (including safety) of development specifications" are often completely different documents.

One sometimes a mere sub-set of the other, thereby allowing (encouraging?) a desk officer (and as you say, sometimes a non-engineer) to sign off a milestone as being complete in accordance with teh contracted spec, whilst still not meeting the development spec.

I think you and I agree that those gaps should be closed, but financial pragmatism dictates otherwise. I'm not defending that, just saying how I see it.

Now I really must get on with some proper (paid) work.
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Old 1st Feb 2014, 09:12
  #323 (permalink)  
 
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Zulu 10, it seems to me that we are all singing from the same hymn sheet, but perhaps from different verses. What you say as a designer is that you assume/depend upon a process of continuous review to ensure that your design was and remains in accordance with the airworthiness regulations. When you designed it you did so within the same regulatory constraints.


That in a nutshell is the system that worked for years, until the late 1980's, when VSO's set out to subvert it in order to balance their books. It has never recovered to this day. That is what has now to be attended to. It is not being resolved by the MAA or MAAIB, nor can it be until they are independent of the MOD and each other. That is the gist of this discussion.


Easy Street, there never was a "Golden Period". That cynical phrase comes from the H-C Report, itself a cynical misrepresentation of history. Any Aviation professional knows that "stuff happens", always did, always will. The point is, what do you do about it? What we did in the 60's was the RAF Flight Safety System and a beefing up of Airworthiness Provision. Avoidable accidents, so rife in the 50's, began to fall but never to zero of course. You do the best you can, and ensure a continuous feedback loop to try to do better. When that system was kicked in the teeth under the auspices of the RAF Chief Engineer, the whole process of continuous audit stopped working, and "stuff" started happening again with a vengeance!
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Old 1st Feb 2014, 09:54
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Ah - there you go again, BEagle! Never miss an opportunity to swipe at the Buccaneer. The Staff Nav was probably so pied off with you that he was working out just how to write up another of your failed sorties! Was it that sortie that led to you being chopped?

No excuse for messing up his pins but, since he knew he was flying with a smart ass, he was probably quite confident that you would sort it out for him!

Back in the Fold

PS. That always assumes that your story is true, of course, and not just more anti-237 OCU BfB (Boocks from BEagle)


BEagle:

I think that the aircraft I flew which had the most pins was the Buccaneer - clearly it was essential to ensure that they were all in the correct position pre-start and also before exiting the aircraft.

On one occasion, I don't know why, but after I'd checked my cockpit, something made me go back and check the rear seat after the navigator had climbed out. Wherupon I found that he'd transposed 2 pins into the wrong locations, meaning that one element of the seat wasn't safe as one pin was longer than the other and wasn't doing its job, being in the wrong hole.

So I relocated them into their correct locations, then joined my navigator in the line hut. True to form, being a 237 OCU staff navigator, the first thing he said was "Where the f*** have you been?". When I told him, he said "Rubbish - and how dare you stick your nose in my cockpit"......

Typical of the sort of treatment we students had to put up with in those days.....
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Old 1st Feb 2014, 11:00
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I must take you to task, Beagle, because I too went through 237 OCU back in the very early 70's. (And sorry to go so off-topic).

The staff were hard on you but I always found their criticism to be realistic and fair. If you weren't up to scratch you were given a roasting. A certain BWI could (and did) bring tears to grown men's eyes!

I always thought that this was perfectly fair as the Buccaneer maritime role was bloody well dangerous and they had to make certain you were up to scratch before you continued with the next part of the course.

I remember Night MDSL (Dive Bombing) at Theddlethorpe Range was particularly challenging and had only total admiration for the Staff Navs who sat in the back without an artificial horizon and only a minuscule altimeter to call out the dive heights and release point.
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Old 1st Feb 2014, 11:04
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"On one occasion, I don't know why, but after I'd checked my cockpit, something made me go back and check the rear seat after the navigator had climbed out."


Sure, the nav cocked up.


But what the devil made you do that?! Very, very strange ---
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Old 1st Feb 2014, 11:24
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cuefaye:-
But what the devil made you do that?! Very, very strange ---
Let's just be very thankful that he did. Perhaps it saved somebody's life. If someone had done the same thing for Flight Lieutenant Cunningham, the OP wouldn't have started this thread. I find your remarks
Very, very strange ---
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Old 1st Feb 2014, 11:56
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PM, Chugalug
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Old 1st Feb 2014, 12:45
  #329 (permalink)  
 
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Fair point, Chug, but cuefaye makes a good point also!

Why would you?

The Buccaneer was very much a crew aircraft and, to make it work, there was a great deal of trust placed both front to back and back to front. There had to be; without that trust the Buccaneer Force would never have been as effective as it was and the role was very, very demanding - particularly, as the Hockham Admiral says, in the maritime role. Backseaters were as much responsible for the safety of the aircraft as the frontseaters and it was never more so than when doing Divisional Dive Bombing or firing a simulated pod full of rockets against a manoeuvring FPB in the dark under you own LEPUS Flare recently delivered in a toss manoeuvre before converting from the recovery into a ten degree dive! Trust in each other in the cockpit and between crews in other proximate aircraft made the Bucc tactics work!

Gone off piste, I know and sorry, but if you didn't show that trust in the cockpit or on the OCU course (either before, during or after a sortie) then you would not have been deemed suitable to pass the course.

'Nuff said!

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Old 1st Feb 2014, 12:48
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Evidence given to the inquest that requires discussion

“In September 2003 I was an instructor at RAF Valley flying a Hawk. It was a night flight sortie. I was in the rear seat, the student was in the front,”
“I did the sortie, landed and taxied along. And I could not put the seat pin back in the hole. I expected it to go back into the hole in the housing and the seat pin* handle. [*pan]
“It would not go through. I could see that the handle was partly caught by a strap. The handle was not completely free from the strap that surrounded it.
“I believe pressure on the strap may have pulled the handle up. If the handle is not correctly sited, the pin will not go back into the hole.
“I was probably a millimetre away from movement that meant I would have ejected. And I was lucky to get away with that.”
An ejector seat has a locking pin, which is pulled before take-off in order for the seat to be made live in an emergency.
The operating handle can then be manually pulled from the safe position through to further settings to activate the seat.
“It is only position three that will set it off, I was at one-and-a-half.
“So the action I took was still the safe thing to do, in terms of pushing it down.”

Q1. Is the seat pan handle linkage levers or cables? (You can't push a simple cable)
Q2. Does pushing the handle back into the housing reset the mechanism
Q3. Did this individual report this incident
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Old 1st Feb 2014, 13:34
  #331 (permalink)  
 
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Zulu

financial pragmatism dictates otherwise
Agree. All I'd say is financial pragmatism should not extend to "savings at the expense of safety". As I said, a safe design, that has been the subject of robust configuration milestones/reviews, is money in the bank on so many levels.

We've discussed this aspect of procurement many times. For donkeys years it has been hammered into procurers and DEC that "80% is sometimes good enough". But the 20% should not include basic safety compromises or waivers. Unfortunately, Sir Robert Walmsley, when CDP, ruled that safety COULD be part of the 20% the Services could do without. Here's your kit, it works but is unsafe. Now shut up and *** off. Happy birthday Sir Robert. There are many who aren't around to enjoy theirs because of this ethos.
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Old 1st Feb 2014, 13:34
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I would say as a Engineer if the handle has come up it must be taking up play in the system hence nothing has moved linkage wise, there is probably a bit of built in play because if there wasn't the slightest knock would trigger the seat when the pin was removed, hence allowing it to move so far before actuation, I also wonder if it is not something to do with putting you in the optimum position spine wise in the seat, the handle needs to be low enough to not get in the way, but high enough to ensure a straight back and not crouched position when operating the handle..
Wasn't that one reason the face blind handles were abandoned, one it gave fractional seconds of indecision between which to use and the other it bent you forward as you pulled it, where as a handle between your legs tends to make you you sit back in the seat when pulled.
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Old 1st Feb 2014, 14:05
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Wasn't that one reason the face blind handles were abandoned, one it gave fractional seconds of indecision between which to use and the other it bent you forward as you pulled it, where as a handle between your legs tends to make you you sit back in the seat when pulled.
AFAIK the face screen puts you in the better posture? i.e. more naturally rather than seat pan where it needs to be practised.

Main reason for seat pan initially was negative 'g'. Then with the Mk9 or so, dispensed with the top handle.

Interestingly, the Mk4 - in the JP and Hunter - with 2 handles, uses the bottom handle as "preferred" in the JP, but the top in the Hunter.

Hunter ACM, with seat pan, emphasises head position v spinal injury. But also says seat pan quicker / better under positive 'g' or if canopy has gone.

NoD
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Old 1st Feb 2014, 14:47
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Nutloose, I don't disagree with anything you say, but I'm expecting a definitive yes or no from a FJ pilot. This is after all, a deadly piece of kit.


But seeing as you took the trouble:-


If you were on a backseat trip and your strap caused the seat pan handle to come out of it's housing


Would you push it back, knowing without doubt that the mechanism was reset?
Would you tell anyone?
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Old 1st Feb 2014, 14:59
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The Swedes had a accidental ejection (in flight) on a JAS39 back in 2007. Is that the same type of Mk10 MB seat? In that case the pins where (naturally) not installed, but they did have incidents on ground on different aircraft with the ejection handle moving out of place when removing pins. Including when collecting a brand new one at the factory I believe.

The inflight one was caused by the anti G suit moving the handle. (Pilot got ejected when pulling G on break over the airfield) Any relevance to this case, or different design?
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Old 1st Feb 2014, 15:20
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Would you push it back, knowing without doubt that the mechanism was reset?
Would you tell anyone?
If I was strapped into it, yes I would push it back in and yes I would tell someone, even before I got out, so they could ensure the right measures were taken, for both my and their safety. I still cannot see how the mechanism would be disturbed.
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Old 1st Feb 2014, 20:08
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Quote:
Q2. Does pushing the handle back into the housing reset the mechanism
Q3. Did this individual report this incident

Unquote.





I find it strange that these questions, particularly #3 are even asked. A firing handle NOT in the correct position makes the whole aircraft U/S, potentially dangerous, until the experts, armourers and E/O have solved the problem and made and declared the seat and aircraft safe so obviously an immediate report would be essential. It's along time since the 12 years when I sat on an MB seat daily but in my day we treated ejections seats with the very greatest care and respect, and I never saw any of my crew or students do otherwise, is that not still so ?

So far as the deletion of the face blind handle, I seem to recall that the primary reason for its deletion was the possibility of being unable to reach it in high G situations, which happened on more than a few occasions, thus making the seat pan handle the primary one when two were fitted and, obviously, your only option on seats such as the Mk10. The advantage of the face blind was that it DID give a good spinal posture, particularly important with an 80 FPS gun as on the Mk4, (it was a hell of a kick, at the limit of what the human spine can tolerate, when not just acceleration but rate of rise of acceleration is so critical) ) and offered restraint and some protection (we did not have automatic clear visors in 60s and early 70s.) for the face and head.

..and still no one has said (or expressed a plausible suggestion) what the SI and coroner's enquiry has stated to be the primary cause of the seat firing ?

Last edited by RetiredBA/BY; 1st Feb 2014 at 20:22.
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Old 1st Feb 2014, 20:41
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I asked the questions because


raytofclimb at post #186 on page 10 and the individual I quote at post #330 talk about pushing the handle back in. Neither of them mention sitting in the seat for an hour afterwards while the armourers make the seat safe.


You, me and Nutloose would be calling the armourers
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Old 2nd Feb 2014, 10:22
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SPHLC,

Q1. Is the seat pan handle linkage levers or cables? (You can't push a simple cable)
Q2. Does pushing the handle back into the housing reset the mechanism
Q3. Did this individual report this incident

From my Hawk recollections;

A1. Yes. The handle is linkages rather than a cable, but the first tiny bit of pull is to remove the handle from the housing rather than start actuating the linkage. You can push it back in. We used to have to do it on the training seats when taking new students for seat briefs etc.

A2. Yes, effectively, as the mechanism's not been triggered. In reality, I doubt anyone would actually reset the seat themselves. Certainly in my time sitting on Mk10s and their equivalents, if you noticed an issue with the seat like this, you'd have an armourer meet you on the line to make the seat safe for maintenance before you unstrapped.

A3. Yes; I remember the HFOR or whatever it was at the time.
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Old 2nd Feb 2014, 11:51
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5 Forward 6 Back
Q1. Is the seat pan handle linkage levers or cables? (You can't push a simple cable)
Q2. Does pushing the handle back into the housing reset the mechanism
Q3. Did this individual report this incident

From my Hawk recollections;

A1. Yes. The handle is linkages rather than a cable, but the first tiny bit of pull is to remove the handle from the housing rather than start actuating the linkage. You can push it back in. We used to have to do it on the training seats when taking new students for seat briefs etc.

A2. Yes, effectively, as the mechanism's not been triggered. In reality, I doubt anyone would actually reset the seat themselves. Certainly in my time sitting on Mk10s and their equivalents, if you noticed an issue with the seat like this, you'd have an armourer meet you on the line to make the seat safe for maintenance before you unstrapped.

A3. Yes; I remember the HFOR or whatever it was at the time.
Thank you for reply.


The usual suspects are limbering up for an Airworthiness debate, something that should command the respect of many PPRuNers, although they are a bit like a stuck record sometimes.


I have mentioned a couple of things that greatly perturb me, in previous posts.


One is that I don't see how they concluded that the seat was unsafe from the previous trip. Secondly, by not allocating blame to individuals, I think that MB are being treated shabbily. I was under the impression that Just Culture does attribute blame.


Waiting for the SI release, I think Airsound said next week
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