I do find it amazing that even folk on here see the 175 /189 as the panacea. The EC225 did a few hundred thousand hours before the catastrophic issue manifested itself. Do folk really think that the 175 and/or 189 don't have some lurking issues with the probability of a catastrophic incident occurring in a few hundred thousand hours? Well maybe they don't, but if so it will be a first in history. Otherwise it is just foolish naivety.

But HC - ignorance is bliss. The current choice being a heli that definitely loses its rotor blades to one that might. I will take the might option every time.

Please be fair....those were the direct result of a Captain's decision to continue flight in direct conflict with the ECL and the Co-Pilot's remainder of that.

Had they ditched as required by the ECL...those Fatalities might have occurred during the Dtiching due to the Sea State, Water Temp, and Winds but the primary cause was the bad decision to continue flight and a slow descent to the surface. prior to the really serious failure.

AH's name is not being smeared.....it is their Management Attitude and patent refusal to aggressively pursue a real diagnosis of the causes of the failures and then coming up with a fix that prevents another occurrence of the same faults.

In my experience, AH might well be chasing the diagnosis of this matter as a matter of quite some urgency, but just not saying so to external or uninvolved sources. Test facilities and specialists may have to be sought and that all takes time. Tests themselves take time to devise and test, then there is the analysis and any rework required....It is not the first time they (AH) have worked quietly in the background. Their PR decisions may be quite different to expectations of publicised openness. Sometimes the less said, the better.
Having said that, the agreement of EASA to a theroretical 'risk management' approach is, I think, diabolical. The UK and Norwegian authorities have the right approach.

I believe you are right.

End of January....no report from AH laying out the exact cause for the 225 MGB failures? I thought it was something quite simple....such as the Gearbox being damaged in Transit somewhere (well one of them anyway) or a Maintenance failure (the other one I suppose).

Sorry but this is unhelpful. I know you are a dyed in the wool EC/AH hater but them not coming up with a cheap explanation is a good thing IMHO. I much prefer them silently chasing the real cause over simply blaming it to transport damage or other 'simple' explanations. If they haven't really figured out what caused it it is better to continue investigating and saying nothing than sending out Wild Guess explanations. They did enough of that in the early phases of this tragic accident.

tbh whatever side of the fence you sit we all pretty much agree on what happened. So the only way forward here is a convincing explanation of why it happened followed by an equally convincing explanation of what can be done to stop it happening again. Let's hope part one of this isn't too far off. Surely that is something we can all agree on.

henra, You are quite wrong about my view of EC/AH aircraft.

Ascribing "hatred" to anyone you do not even know is a bit over the top.

I am not alone in my view the management has handled this situation poorly.

Perhaps it is your own prejudices you might consider before you go slanging other folks.

For sure....they appeared to have dropped the ball between the two fatal crashes or perhaps they might have been better able to have avoided the second one don't you think?

There is no doubt Airbus are working extremely hard to determine the root cause, the future of the 225 depends on it. Honestly, Airbus's future in the O&G world largely depends on it. Frankly these days, they are probably better off putting their efforts else where anyway, the O&G world is so cut throat, they will soon be expecting operators to pay to fly for them.

One thing that has struck me a bit odd is all the design questioning. All the load anaylsis, material anaylsis, cycle counts, bearing types, rotation counts, number of blades, number of suspension bars, weight reductions, power increases, and on and on ........All, over the top blabbering IMO ...... The L2 flew for how many years? About 18-19 years before that gearbox failed. I don't care who you are, after almost 20 years of operation of any mechcanical item, do you go straight into believing there is a design flaw or a structural integrity problem? Probably not! The next similar failure of the same component, 7 years later, 25-26 years after design and about 12 years into the 225 life .... Design problem? Again, probably not.

We all know they have a problem and Airbus knows they have a problem. Have they probably found a common denominator with the one bad planet gear manufacturing? Has something changed in the manufacturing of that gear ... It's been working for 20 years? Was that part number available from design conception or was it brought into play XX years after gearbox design to keep up with demand? If yes to any of the above, is removing them from service and just running the more reliable gears an acceptable solution? Maybe the later coupled with the lower TBO and increased maintenance monitoring (10 hour chip and filter inspection) is enough? Maybe there could have been rough handling of the gearbox? Could there have been a maintenance error? In my opinion, all valid questions and probabilities ... None that seem anymore or less out to lunch then a poorly designed gearbox that managed to work faithfully for 20 years. Some have been ruled out while they continue to hammer away at others I'm sure.

Unfortunately, no matter what cause is determined, they will probably never be able to convince us that enough is done .... The pure nature of the accident, fatal with little to no warning (I says this lightly, REDL did try to throw some failure indicators in time), makes the solution hard to swallow.

If you use the gearbox oil shaft failure as an example .
AH changed the original manufacturing process. It stopped countersinking the 2 stress relief holes from joining the two part shaft.
The Plastic bung was no longer a snug fit,ergo condensation got in ,corrosion, failure, two helicopters in the sea.
Reputation ruined.
All caused by one minuscule "Saving".

Probably not.

You’ve probably hit the nail on the head. Unfortunately most people who currently have a 225 on their books has had the EC/AH experience, customers and authorities.
Buying experience consists of legions of shiny suited salesmen saying the obvious we are no 1 performance wise.
What creates problems down the line is when things go wrong, from cutting edge technology it’s flashbacks to the school yard. He did it, it’s not me. It can’t happen again ( oh yes it can).
It’s a shame the EC225 will die due to corporate/product support arrogance and their default position of this is one for the lawyers as opposed to this is one for the engineers.

Which L2 are you referring to? G-REDL didn’t fly for 18-19 years (it was built 2004; crashed 2009). Its first MGB epicyclic module certainly didn’t either. From the AAIB report 2/2011:

“1.6.8 In June 2004 the epicyclic module (manufacturer’s serial number M2088) was removed for overhaul due to the presence of metallic particles being found on the magnetic chip detectors. The module had accumulated 844 flying hours since new. During this overhaul all the first and second stage planet gears were replaced with new units”.

Not a design issue? Halfway through its first year of service? Remind me what the designers originally set as the TBO and SLL for epicyclic components, and for MCD physical inspections? What are they now? There appears to be a huge variation in life expectancy on this planet gear component. Why? How long had the gearbox been in LN-OJF? If it is not a design issue, are you in effect saying the MGB is well designed but badly manufactured?

You may be right though, the planet gear issue may be a manufacturing problem more than a design error, although manufacturing parameters and limits have to be set by design engineers to keep the product within design assumptions otherwise the design and any certification thereof is simply invalid. But the architecture of the 225’s MGB is such that fracture in a single planet gear is enough to bring down the aircraft and that gear and failure mode is one of the hardest things in a helicopter to actively condition-monitor. That is where it has a very, very serious structural integrity problem. Not just the planet gear itself; that is just one of the 16 eggs in the basket, the basket itself (ring gear) being rather fragile and critical in retaining the mast.

How many other manufacturers have planet gears that fragment in flight? How many other AH helicopter models suffer that catastrophic failure? Not a design issue? I find that pill hard to swallow. Then again, no-one is forcing me to.

Ohh, you're definitely not alone on this. AH management totally f***ed this up. Royally.
And that is why I consider silence on their side already a progress. They need to properly understand the real cause before coming up with the next half baked excuse.

Which prejudice? I noticed a severe attack from your side against AH/EC for not coming up with the next explanation and I was genuinely confused why you would damn them for thinking before speaking out after (absolutely rightfully) crucifying them for prematurely coming up with an explanation (that put the blame wrongfully on others)

Absolutely. This should serve as an industry example how not to deal with a technically caused catastrophic failure.

Concentric,

My reference to G-REDL would be the date it crashed (April 2009, you are correct). The original type certificate for the L2 was EASA approved 12 June 1991. Guess I was off slightly, not quite 18-19 years ... More like 17.5 years. That said, the L2 variant operated for 17.5 years with the "design" of gearbox and epicyclic before it failed in that way. Obviously REDL's epicyclic wasn't physically 17.5 years old, but the design was .... That's my point. In that 17.5 years, how many epicyclic modules went to the full TBO, the original TBO. If they never made TBO, they held together to bring everyone home safely. So what has changed ... Not the design.

When OJF crashed April 2016, the "design" of the epicyclic would have been about 20 years old in total and would have been sitting in the 225 for about 12 years.

What I'm saying is, I do not personally find a component design that has operated for 17.5 years a poorly designed component. The eggs in the basket theory may be a bit out there as well. I would say "every" gearbox out there has one rotten egg that if it cracked it would spoil the whole carton.

I appreciate your rationale. It seems to point to a manufacturing change - either a step change or some kind of drift in quality.
However, it was noted in the REDL investigation report that the original design analysis of the planet gear overlooked a frictional shear component in loading between rollers and the outer race which enabled a crack to radiate beyond the residual compressive zone that had been an original design assumption. The manufacturer had another 2nd stage planet gear removed from a gearbox in 2005. When sectioned (at an undisclosed date) that exhibited just such an example of an outward radiating crack proving that original design assumptions had been incorrect.

There was another design failing reported by AAIB on the bevel gear shaft stress analysis that I have mentioned before so won't bore you with here except to say that it didn't even meet the manufacturer's in house minimum factor of safety. At least AH redesigned that and the difference is actually promoted in a PR video available on youtube.

Which Model/Type of "Puma" did they have to reduce Cruise Speeds on to stop their going through MGB's like unsupervised Kid's going through the contents of a Cookie Jar? It was told to me that getting to TBO on the Gearboxes was impossible until Power Settings (thus cruise speed)were reduced then all was well.

MCP wasn't changed so no change in cruise. It was reinforcement of the max speed above which TO power was not allowed.

The Sultan

No, on the 332L (Bristow Tigers) MCP was reduced from 16.5 degrees to 15.5 degrees of pitch. Cruise dropped from about 145 to 130 its.