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EC225 crash near Bergen, Norway April 2016

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EC225 crash near Bergen, Norway April 2016

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Old 9th May 2016, 19:21
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Originally Posted by Satcomm
SMW72, the inspection plate being found in the hangar was mentioned but really holds weight in my rant with the fact of continued missed inspection (not seeing the that the plate was missing).
Ok. I stand corrected. I must have missed that thread. Sorry.
But again, none of this has been confirmed by the investigators? So...rumour?
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Old 9th May 2016, 21:19
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We have crafted complex methods in efforts to prevent these tragedies but somehow no matter what we do there is something that happens to trip us up in achieving that goal.
Its called Risk compensation. Weird human failing.

Risk compensation

The "offshore business" is high risk by its nature and probably always will be.

Some may have forgotten.
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Old 10th May 2016, 03:54
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Twist & Shout
“I think it's pretty unemotional and factual, that at this time there is an unexplained catastrophic failure involving EC225. (Perhaps it would be irrational to be happy to fly an EC225 under the current circumstances, even for say, SAR.)”

T&S. Can I assume your meaning of “happy to fly an EC225” is an expression of your accceptance to fly the aircraft whilst not being comfortable with so doing ? Or vice versa ??

I believe there are three groups of EC225 pilots out there. Those who will fly it on SAR , those who will not fly it at all (or at least until a definitive cause is established) and those who are as yet undecided (or who are in a position where they do not have to decide right away).

I am personally in the latter group and am extremely conflicted about the issue.

Unfortunately the various AUTHORITIES/COMPANIES/MILITARY are in disagreement as to flying the aircraft. All have a different outlook.
As in :-
1. Nil commercial flights
2. Nil passenger flights but SAR is ok
3. Nil flights what so ever

A pilot normally assesses a myriad of factors before he accepts a flight. If he cannot come up with tics in all the boxes then it is a NO GO.

My question is , how can any pilot put tics in all the boxes when there is still an unknown as to whether it was a MAINTENANCE failure or an OEM failure irrespective of what category of flight it is. How can any AUTHORITY/COMPANY/MILITARY condone the release of the aircraft given the above unknown.

Category of flight is irrelevant. Empty ? SAR ? Makes no difference! At the very least there are still “two joes” sitting up front flying a machine with a potential “unexplained catastrophic” fault.
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Old 10th May 2016, 04:49
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You just have to stand under the rotor while it's running to know there are some bad Harmonics going on there somewhere.
That in itself can only lead to fatigue issues in the long term.

Fix that terrible Kidney bashing beat the piece of Junk produces and you might have a half decent helicopter
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Old 10th May 2016, 06:18
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For those who quote the 4 million hours figure, Total Super Puma fleet hours at the end of 2015 were over 5.2 million, the 4 million are mk1, 730k on mk2 and 546k on 225.
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Old 10th May 2016, 06:51
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How can any AUTHORITY/COMPANY/MILITARY condone the release of the aircraft given the above unknown
Apparently all of them except CAA UK and Norway.
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Old 10th May 2016, 16:46
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Might the tripod solution and the retention of the bolts by washer and nappy pins be fundamentally a bad design? Why does an office chair have five legs and why circlips have been invented being more resistant to axial forces and to wear by vibrations? A Cotter Pin 'Fokkernadel' is not constructed to transfer larger forces and the washer is like a punching tool.
Please see https://www.yumpu.com/xx/document/vi.../fokker-nadeln

Last edited by AW009; 10th May 2016 at 18:45.
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Old 10th May 2016, 20:06
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AW009
Easy to criticize a design after a crash...
What is preferable ? Fragile circlip or ductile safety pin...?
To be honest, over the time, it is difficult to say.
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Old 10th May 2016, 20:06
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three rods all of which are required to work at the same time for a successful result is a long way from the redundancy concept
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Old 10th May 2016, 20:10
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Originally Posted by SMW72
The other misconception is with regards the inspection process. You may be looking at it from a UK point of view which make your assertions spot on but in Norway engineers can Dupe their own work so an independent inspection is never required under their legislation. This may seem ridiculous to many on here but it is how it is.
Really? Norway applies the same Airworthiness rules as the rest of Europe, and both Part M and 145 require independent checks and critical task error management philosophies. Having the same guy doing his own duplicate inspections doesn't seem to achieve the same safety level.
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Old 10th May 2016, 20:21
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three rods all of which are required to work at the same time for a successful result is a long way from the redundancy concept
Some other designs put the whole load through a single highly stressed MGB casing.
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Old 10th May 2016, 21:41
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Originally Posted by AnFI
three rods all of which are required to work at the same time for a successful result is a long way from the redundancy concept
A helicopter does not have a lot of redudancy at all. There are hundreds potentially fatal single points of failure.
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Old 10th May 2016, 21:54
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EC225 Main Rotor Head and Main Gear Box Design - Aerossurance
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Old 10th May 2016, 22:29
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Originally Posted by AW009
Might the tripod solution and the retention of the bolts by washer and nappy pins be fundamentally a bad design? Why does an office chair have five legs and why circlips have been invented being more resistant to axial forces and to wear by vibrations? A Cotter Pin 'Fokkernadel' is not constructed to transfer larger forces and the washer is like a punching tool.
Please see https://www.yumpu.com/xx/document/vi.../fokker-nadeln
Office chairs with five legs !!!! What office do you work in?

Three legs provide perfect stability. Have you never been in a restaurant at a table which rocks from side to side? Chances are it had four legs. Remove one leg and it will be rock steady.

Seriously, at the end of the day, any helicopter has to have a system which suspends the fuselage from the rotor head. The three support rod system has been in use for decades without problem. If it is designed, fitted and maintained correctly and there are no faults with the materials then it as as good as you will get.

Don't forget the barbecue plate is also a stressed component.
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Old 10th May 2016, 23:53
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Sorry....not Risk Compensation at all.

That would suggest becoming immune to there risk over time.

What I am talking about is Mr. Murphy and all of his Cousins that constitute the Human Being that is the weak link in the Safety Process.

There is no accounting for how dedicated some folks can be at thwarting the best designed set of procedures, policies, and practices....as often by sheer randomness as much as with malice aforethought.

The rest of your referenced concepts also hold true.
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Old 11th May 2016, 01:12
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@roundwego: How many fasteners attach the BBQ plate to the transmission deck?
Also: just FYI, three of the four office chairs in my house, and most of the office chairs in the office where I work, have five rolling wheels. It appears to have become a standard among certain office furniture manufacturers.

For lowfat: link was very informative/useful.
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Old 11th May 2016, 01:55
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three rods all of which are required to work at the same time for a successful result is a long way from the redundancy concept
With regards to failure modes/effects, "redundancy" and "single point failure" are not really the best terms to use. Like all other aircraft, rotorcraft systems/structures are designed to provide a specific level of fault tolerance (zero, single, or dual fault tolerance) based on a criticality designation for the function, classification of the failure condition (no safety effect, minor, major, hazardous, or catastrophic) and the probability of the failure mode (probable, extremely remote, or extremely improbable) determined by a failure mode effects analysis (FMEA).

For example, there are numerous components on a rotorcraft, such as the main rotor shaft, performing a function designated as "critical", which have no fault tolerance (or redundancy), and the failure of which would likely be "catastrophic". But it is acceptable if a catastrophic structural failure of the component can be shown to be an "extremely improbable" event by FMEA. Of course, this is based on the fact the FMEA takes into consideration that the component will receive special analysis (fracture, fatigue, etc) during design, special QA processes during manufacture, and special monitoring/inspections during service.
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Old 11th May 2016, 03:36
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this is based on the fact the FMEA takes into consideration that the component will receive special analysis (fracture, fatigue, etc) during design, special QA processes during manufacture, and special monitoring/inspections during service.
More importantly.....it presupposes no failures in any of those processes at any point during the life of the aircraft and its affected parts.
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Old 11th May 2016, 04:43
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Sasless,

Depending on who you talk to coming to unsavoury and unfortunate end hasn't changed in the UK
since the 13th century!
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Old 11th May 2016, 04:52
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Originally Posted by SMW72
The other misconception is with regards the inspection process. You may be looking at it from a UK point of view which make your assertions spot on but in Norway engineers can Dupe their own work so an independent inspection is never required under their legislation. This may seem ridiculous to many on here but it is how it is.
But as many have said on here we are all just listening to rumours and it may be a long time before we know the correct details.
My thoughts are with the families of those affected by this tragedy.
Originally Posted by FiveGirlKit
Really? Norway applies the same Airworthiness rules as the rest of Europe, and both Part M and 145 require independent checks and critical task error management philosophies. Having the same guy doing his own duplicate inspections doesn't seem to achieve the same safety level.
This is not correct. The same rules apply in Norway. Duplicate inspections are required.
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