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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 30th May 2016, 11:06
  #1001 (permalink)  
 
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AIBN has released photos of all 3 upper ends of the struts showing main pins and nappy pins. They now say that they have all three mounting brackets for the lower ends and we have seen photos of only two, both with main pins and nappy pins.
The front strut is missing a center section, we don't know how long it is.
The answer they gave to the journalist about whether they recovered all pins and bolts is still not 100% clear., at least to me. We know the 12 mount bolts may have been ripped out during the event.
AH suggests that this event it is a strut problem . . .
If AH has seen all 3 brackets and both ends of the strut that broke in 3 pieces then they must have concluded something (with their lawyers of course) that makes them feel the 225 is safe to fly.
A photo of the lower bracket and the remaining lower front strut with any recovered fittings would be a big event but I have limited expectation that they will release that to the public.
It could be a deal breaker IMHO.
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Old 30th May 2016, 14:14
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Originally Posted by henra
Holy crap.
Why are you so desperately panicked to insist on one cause despite not even the Investigators being sure about the cause at this point in time. Did you think about talking to your psychiatrist about this?

A little bit of speculation is fine but what is all this crap with you Amateur accident investigators all about? And any one who doesn't follow your amateurish reasoning blindly will be madly attacked by you.

Is it asking too much to wait with the final verdict until someone KNOWLEDGEABLE has come up with some real evidence (not Armchair evidence)?

(Taking this one of your posts randomly I could have chosen any other one.
Here's hoping your not a Professional Pilot (Or professional anything else for that matter)). Rant over!
Thank you henra : so much crap being published on pprune made me loose interest in opening this website , especially in the rotorhead section where too many non-professional dare to express their fantasy .Good to know that you exist and dare to put people where they belong.
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Old 30th May 2016, 14:38
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AH came out 48 hours after the accident and effectively said this was not an epicyclic incident.
Birimingham, I believe you are wrong with the above statement. They said that it was not a repeat of the issue that caused the 2012 ditchings. Which has nothing to do with the previous epicyclic failures.
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Old 30th May 2016, 15:37
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Indeed thank you for the correction. It wasn't until 27 May they openly stated that epicyclic failure was improbable. They have, however, been alluding to the suspension bar failure mode from the outset and still are. I can't believe they would do this unless they could stand it up. But we will see.

Last edited by birmingham; 30th May 2016 at 15:54.
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Old 30th May 2016, 16:06
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Originally Posted by Satcomm
Birimingham, I believe you are wrong with the above statement. They said that it was not a repeat of the issue that caused the 2012 ditchings. Which has nothing to do with the previous epicyclic failures.
Looking at AH's statements I disagree, although the statement came after 4 days. After 2 days/48 hours they only lifted the grounding of the EC225LP. Their statement at May 3 includes:
Originally Posted by Airbus Helicopers
At this stage and based on the latest information, preliminary inspection of the main gearbox vertical shaft shows no link with the 2012 ditching events.

In addition to the SIN 3031-S-00 and based on the on-going root cause analysis process, precautionary measures are requested:
An airworthiness directive has been issued requesting measures newly defined in the EASB 53A058 and additional one-off maintenance checks.

The EASB 53A058 requests the verification of the correct installation of all MGB suspension bar attachments for the EC225LP. Similar measures will be published shortly for the EC725AP in a specific ASB.
EASB 53A058 also issued May 3 only calls for inspection of the suspension bars while EASA AD 2016-0089-E calls for inspection of both suspension bars and gearbox (although only for metallic particles and HUMS data). Both are issued May 3, and this further implies that AH consider the suspension bars the only possible cause.

Then on May 27 they finally dare to say what they have implied (that they consider a suspension bar failure the only probable cause) all along with:
Originally Posted by Airbus Helicopers
According to Airbus Helicopters’ analysis, seven potential initial events have been retained to explain the main rotor detachment of LN-OJF. Out of these seven scenarios, only one – the failure of the attachment of a suspension bar – can be assessed as probable by Airbus Helicopters, based on the information available to date.

At this stage, the exact cause of this possible event is still unknown. Analysis of the helicopter’s maintenance history has just started and should provide a better understanding of the most likely causes.
In the second paragraph quoted they also use this statement to imply that the cause can be found in the maintenance history and thus isn't a design or manufacture issue.

I know that you didn't comment on what AH said May 27, but I think it makes it easier to "read between the lines" in their earlier actions.
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Old 30th May 2016, 16:38
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I am completely confident in these aircraft, H 225, because I am pilot of Super Puma since 1990, and I HAD NEVER HAD a RED emergency. I have around 5000 hours flying L1 and 225. For me it is clear that the problem in LN-OJF, it is not inside the MGB. Both scenarios of epicyclic or conical housing would be accused in HUMS or in the FCP. No of them wouldd immediately break without any warning. Because of these I agree with AH and their last statement :

Originally Posted by Airbus Helicopers
According to Airbus Helicopters’ analysis, seven potential initial events have been retained to explain the main rotor detachment of LN-OJF. Out of these seven scenarios, only one – the failure of the attachment of a suspension bar – can be assessed as probable by Airbus Helicopters, based on the information available to date.

At this stage, the exact cause of this possible event is still unknown. Analysis of the helicopter’s maintenance history has just started and should provide a better understanding of the most likely causes.
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Old 30th May 2016, 21:18
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The report also provided an update on the retrieval of data from the aircraft’s health and usage monitoring system (HUMS). It stated that due to HUMS data being saved on a memory card only after a helicopter has landed, data from the accident flight was not available.
Latest News
http://www.verticalmag.com/news/arti...ause-scenarios
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Old 30th May 2016, 23:00
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Potential initial event 7): Suspension bar attachment failure
This potential initial event may have two main different origins:
1. Detachment of suspension bar fitting from the airframe: such a detachment could be due to failure of
attachment fitting bolts.
Airbus Helicopters is finalizing additional calculations and fatigue tests. Conclusions are expected in
the beginning of June 2016.
2. Displacement and disengagement of one suspension bar pin due to the absence of safety pins
Dedicated tests are being done to further assess this scenario. Results are expected by end of June
2016.
The AIBN investigation team is still searching for the missing parts from the front suspension bar at the
accident site.
At this stage of the investigation, Airbus Helicopters considers that this potential initial event is not
contradicted by any available technical evidence.
For all potential initial events, analysis of the helicopter’s maintenance history should support a better
understanding of the most likely causes.
Airbus Helicopters will provide updated information as the investigation progresses.
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Old 31st May 2016, 00:06
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HUMS analysis is only as good as the signal picked up by on-board accelerometers.
A shame the data is not recorded - surprising also.
Planetary systems are notoriously difficult to record early symptoms. This is due to the signal loss through the carrier to another bearing before it can get to a nonrotating hard mount. On direct locations adjacent to bearings, they are very good at picking up small benign issues. On planetary systems a defect noise is faint, and washed out by all the other planet clash that passes around the ring.
Absence of HUMS signal does not mean absence of problem in the epicyclic. In fact if there was any sign previously, then it was probably already more developed, enough to actually affect the planet clash by large deflections.
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Old 31st May 2016, 07:21
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AH published a new SIN yesterday. They are still pushing the suspension bar issue. There will be a new ESB about it shortly. One point they made which I don't think has been covered on here, is that (they say) there is evidence that the engines and tail rotor were still running / being driven up to the point of impact which, they say, shows the epicyclic didn't seize up.
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Old 31st May 2016, 07:47
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Interesting additional comment from them today!:

May 31, 2016

Following the statement published on May 27th, Airbus Helicopters feels the need to clarify its position to avoid any possible misunderstanding.

Airbus Helicopters is not ruling out any of the scenarios described by the AIBN in its updated preliminary report into the tragic LN-OJF accident. Although significant progress has been made in analyzing information regarding the suspension bar attachments, more work needs to be done on scenarios involving the epicyclic module and the MGB conical housing.

We would like to stress that our chief priority is to further support the ongoing AIBN investigation and to identify the accident’s root cause
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Old 31st May 2016, 08:34
  #1012 (permalink)  
 
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"Bergen Crash is the writing on the wall" or "the catalyst of doom"

Originally Posted by HeliComparator : One point they made which I don't think has been covered on here, is that (they say) there is evidence that the engines and tail rotor were still running / being driven up to the point of impact which, they say, shows the epicyclic did not seize up.
Running engines and running tail rotor must in principle not be a proof that the Epicyclic modules suffered no self-destruction. This seems to me as a very weak argumentation because the two engine drive shafts and the tail rotor drive shaft are below the bevel gear and the epicyclic gears, see https://www.youtube.com/watch?v=UnpvtFQowKc

@Jdbelo: Although or just because you are (military? Brazil?) pilot of Super Puma since 1990, may be that you assess the situation a little bit unrealistic? The EC225 crash near Bergen has to be seen in a larger context, under technical and economical aspects and under the tooth of time, especially if the epicyclic gear box will prove as cause.

More than ever, the old adage is relevant 'A liar will not be believed even when he speaks the truth'. This spirit runs like a red thread through the history of (Super) PUMA, NH-90, AH-TIGER, A400M, EUROFIGHTER, EUROHAWK and the UAV-Scenario. The ‘Bergen Crash’ might be the 'Causa finalis' for a mutual gloom and doom. AIBN, Norway CAA and UK CAA know these interdependencies and their serious implications very thoroughly. Therefore they will take their time for the final report, which probably might be the ’coup de grâce’.

AIRBUS Helicopters, AIRBUS Defense & Space and ’Major Tom’ have forgotten in the past, 'the higher the energy of the particle collision, the deeper physicists are able to gaze into the proton, and the more details are revealed'.

Up to now AIRBUS Group is loosing itself within each distinguished project in more or less stupid tactics of cock-and-bull stories about any shortcomings in catch-up development, about gap-fill of quality failures and about lack of delivery reliabilities and this is the cause for having overslept solid corporate strategies. The military must repent and pay for what they have ordered. In the industry however, the rules of supply and demand and of free competition are valid.

This behavior seems typical of an artificial or state-created (Germany, France, Spain, UK) Major Corporation, which is indeed in the meantime pseudo-privatized, but as an European monopolist also lives on hidden subsidies in future. Just have a closer look at the Annual Report 2015 of AIRBUS GROUP. 50% of external revenues are attributable to defense and 19.5 billons Revenues of divisions AH and AD & S are representing 46% of total revenues.

Airbus Helicopters took after deduction of 50 cancellations for government helicopter a total of 181 net orders. The new orders included orders for 38 x H175(!) and 67 x H145. The product sales of Airbus Helicopters presents a total of 53% of external revenues, the remaining 47% were are achieved by services.

In 2015, the order situation was much better: The 383 net orders are divided:
H120 / H125 / H130 series: 163; H135: 49; H145: 107; H155-series, 13;Tiger: 7; NH90: 6; H175: 36 (!); H225-series: 2 (1 = Japan Coast Guard (JCG), scheduled for delivery by the end of 2018).
(compare http://www.airbusgroup.com/dam/asset...us%20Group.pdf and http://www.airbushelicopters.com/web...kten_1903.html)

Whilst expectations of crude oil and natural gas industry for the coming three years are lower than previously anticipated (by between -4% and -7% year-on-year) the overall picture remains a long-term growth story with the offshore helicopter industry expected to be relatively resilient as the majority of demand will arise from ongoing production phase support. To take a Pollyanna view of Helicopter Offshore OPs, the coming years will be an important time for the industry as a new generation of medium-class helicopters, such as the S92, H175, AW189 and and soon Bell 525, will continue increasingly their introduction. These models are characterized by technical growth potentials, highly efficient with new advanced safety systems and are, therefore, expected to perform well in the offshore arena. But H225 is trending towards the tribal wisdom of the Dakota Indian ’When you discover that you are riding a dead horse, the best strategy is to dismount.’

Therefore the “Bergen Crash“ will prove as the key issue for the future of AIRBUS Helicopters as well as for AIRBUS Defense & Space and the aforementioned projects. TIGER (in Australia), NH90 (in Australia and Sweden) and H225-series (worldwide?) are already spinning in a death spiral.

(just my 2 cent or my purely personal assessment of the market situation).

Last edited by AW009; 31st May 2016 at 08:53. Reason: formatting
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Old 31st May 2016, 08:35
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Originally Posted by HeliComparator
AH published a new SIN yesterday. They are still pushing the suspension bar issue. There will be a new ESB about it shortly. One point they made which I don't think has been covered on here, is that (they say) there is evidence that the engines and tail rotor were still running / being driven up to the point of impact which, they say, shows the epicyclic didn't seize up.
tbf any reponsible manufacturer would do this. They obvious believe that this is the most likely of the seven scenarios and one of the seven where a SIN and associated checks could have most benefit. It is difficult to see what nore they coud suggest to monitor the epicyclic without a redesign. The encouraging news is they are working on tests to stand up this theory and they don't yet completely disount the other 6
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Old 31st May 2016, 10:51
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Originally Posted by AW009
Running engines and running tail rotor must in principle not be a proof that the Epicyclic modules suffered no self-destruction. This seems to me as a very weak argumentation because the two engine drive shafts and the tail rotor drive shaft are below the bevel gear and the epicyclic gears, see https://www.youtube.com/watch?v=UnpvtFQowKc
There will presumably be a weak point that would likely shear or at least be severely damaged in the event of a sudden stoppage of the epicyclic. Personally I have no idea where that might be but it seems AH do, and they think it is between the engines and the bevel gear.
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Old 31st May 2016, 11:50
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"The harder you have to work to deny you have a problem....the greater the problem you have."

Paraphrasing the comment a well known Helicopter Design Engineer and Test Pilot once said.
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Old 31st May 2016, 14:00
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Nadar, once again I do not believe Airbus has ever said that it was not an epicyclic failure. Just that it definitely was not the same issue that caused the 2012 ditchings.

And again with the latest statement, if you "read between the lines" obviously yes, they want it to be a suspension bar failure or some sort of maintenance issue. However, every statement they made to date has a "but we could be wrong ending". The 7 possilble cause statement ends with a statement about "information available to date". The maintenance history statement ends with the word "causes." This could be viewed as "causes" to the suspension bar failure or which of the 7 possible "causes" may be the cause.

The news over the pass few days have been reading between the lines as well and reporting what they feel as Airbus definitively saying it's not a gearbox issue and that they pinpointed maintenance. (Are you a reporter?) Airbus are obviously reacting to this propaganda and clarifying the issue, with more smoke and mirrors!!
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Old 31st May 2016, 14:29
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@HeliComparator, @SASless: Just have a look on https://www.youtube.com/watch?v=oD4jKBOIBwc ,
https://www.youtube.com/watch?v=iJKZPbf_kPI
https://www.youtube.com/watch?v=2SdJvHUuBgg

.

Last edited by AW009; 31st May 2016 at 17:11. Reason: link corrected
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Old 31st May 2016, 15:40
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After the enquiry

Unfortunately it is now looking very unlikely this machine will survive, at least offshore.

If it is another epicyclic then the game is effectively over and everyone will start the slow or not so slow conversion to other types.

If it is (as they clearly expect) the suspension bar, maintenance related or not. then they will have to explain to an already spooked workforce why the failure of a single item; bar, bolt, or worse missing nappy pin would result in the destruction of the entire structural integrity of the machine.

Now sure, there are many single points of failure on a helicopter- we know that. Many are completely unavoidable.

But could the design of the sus bar assembly have redundancy built in? Other types have at least some. If so why didn't it?

The public will see it this way whatever we think.

The puma in all its types has been around a long while

Recently 5 accidents 7 years 3 fatal 33 dead. All in the NS. 1970s levels of fatal accidents. Regularly grounded, rapid redesigns.

A series of "extremely improbable
" events will "extremely probably" mean the end of the road this time.

Maybe I am wrong, but even If I am I would certainly wager we will never see another AH helicopter with a zero redundancy three bar mrh suspension arrangement.

Last edited by birmingham; 31st May 2016 at 16:16.
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Old 31st May 2016, 16:34
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Running engines and running tail rotor must in principle not be a proof that the Epicyclic modules suffered no self-destruction
Is it is possible that if the MGB epicyclic module seizes the connection to the engines is lost and the resulting inertia is to small to stop the engine from shutting down due to overspeed ? And, wise versa, if MGB still intact the inertia is big enough to allow the ECUs to limit power before overspeed rpm is reached ? Just a thought, to try to understand AH...
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Old 31st May 2016, 16:59
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@Satcomm I'm not a reporter or in any way a party in this. Neither have I landed on any specific theory that I believe strongly in.

I simply react to AH seemingly trying to "guide" the opinion in a certain direction. If they turn out to be correct I guess their actions can be justified. I simply have a hard time to believe that they have strong enough evidence to take this stance without being able to convince AIBN of the same.

The only thing I am fairly convinced is that the earlier much discussed missing suspension bar bolt or nappy pin is too simple a solution. Except for that, I'm still very much open minded and frankly don't have the expertise or depth of knowledge about this to draw any further conclusion.

Last edited by Nadar; 31st May 2016 at 17:46. Reason: Grammar
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