I didn't think the hotspots were a result of corrosion.

My take on it is that the hotspots are an independent factor in relation to the corrosion. I expect they are a variation in residual welding stress occurring around the weld. A number of cycles of variation in residual stress might occur around the path of the weld. This will include areas that are free of residual stress and areas that might have several times the average residual stress and which might be termed 'hotspots'.

I think we are well informed HC. Isn't your company talking about bringing back the 225 at a reduced power and speed of 130 knots. Perhaps you would explain the reasoning behind a reduced capability return to service plan?

TM, as far as I am aware nothing is decided. Reducing power is one option that might be seen as demonstrating a desire to maximise safety to placate those of a nervous disposition. On the other hand I would agree with you that this could be seen as showing a lack of confidence - anyway it would be a political decision rather than a technical one.

The person at the EC presentation who asked that question about flying at reduced speed and power, was told by the EC representative that there is no need for it. The factor of safety while flying at MCP will still be much greater than the regulatory design requirements.

However I think he might still push for it in the company, similarly to whoever dictated that the S61N should still fly at 110 knots, long after the short-spar blades had all been withdrawn from service.

He'd probably decree that reduced speed should be adhered to until all gearboxes get the new shaft. It would be a pity to penalise the aircraft with such a belts, braces and nappy pins approach when belts and braces will be more than adequate.

That's an interesting discussion. Even though it may be a conservative approach, wouldn't flying at a reduced speed (notwithstanding the additional flight times) show the aircraft to still be "sick"?

Excellent point. I hope he reads this. Perhaps HC might make that point with him.

Colibri, I know that the gentleman in question has no desire to see the 225 returned to service at reduced power. I think he asked the question in order to get the answer that there was no technical justification for it. However this decision will be taken higher up the food chain I suspect!

A ship sank about 150 miles offshore and survivors were clinging to anything that would keep them afloat in the rough seas. One devoutly religious man was hanging on to a small log, confident that God would look after him and that he would be saved.

In due course, a rescue helicopter arrived and the man told the winchman ‘rescue others first – the Lord will save me’. A second helicopter arrived and again the man told the winchman ‘rescue others first – I am confident the Lord will save me’

A short time later, the man lost his grip on the log and drowned.

When he eventually arrived in heaven (after all the paperwork was processed), he asked if he could have a word with God. He stood before the Lord and asked ‘Why did you not save me from the sea?’ God checked his records and said ‘I sent two helicopters to save you’ And the man replied ‘Yes, but they were EC225’s...’

It appears the CAA in Norway today issued a revised Safety Directive allowing the EC225 to operate in a hostile environment again.
It is published here.

I am not quite sure I get your humour rotorbody, its not witty really. there is no humourus reference to the 225. In any event, that kind of stuff belongs on Jet Blast.

Need someone to explain the humor in that for you?

It is very subtle......which appears to be quite lost on you.

I always heard said that it was three helicopters and two boats.......but oh well....even then that might confuse you a bit.

It must be a religious joke Sasless, which is why you God fearin' Americans would get it and I probably wouldn't. Tell it in church (or chapel) on Sunday and see if they laugh!

But please do explain the humor, as I really genuinely don't get it.

Did you hear the one about the humourless helicopter piot who tried to give a bunch of church-going Americans a lesson in humour and athiesm?

:rolleyes:

.

"CHC Helicopter has begun flight tests of aEurocopter EC225 fitted with the full range of EASA-mandated safety modifications from its base in Aberdeen, Scotland, as it attempts to return its global fleet of 32 of the type to operation"

"Now CHC is on track to be the first operator to get its EC225s back in the air, with the initial unidentified aircraft having received Eurocopter's safety fixes, following their approval by EASA on 9 July, and commenced flight trials on 18 July"

"Pan-industry organisation the Helicopter Safety Steering Group met on 17 July to discuss its position in relation to the EC225 and says it "fully supports" the plan to allow the helicopter to resume flights"

PICTURES: CHC flight tests fully modified EC225, targets rapid return to service

.

Will be interesting to see how the passengers feel about getting aboard again?

CHC mentioned a couple of days ago at an industry briefing that they had performed the NDI on all their aircraft with no more cracks found. They have completed the cleaning procedure, and are progressively installing the EMLUB, MOD 45 and oil jet modifications.

No cracks found on our aircraft either, which was pretty much a forgone conclusion. If we had found any cracks, that would be a major disaster because that shaft would then be a few hours or tens of hours away from failure.

Really? How?

Again I admire your optimism. Which part was concluded without an inspection?

RVDT, what I mean is that once a crack is formed, its a matter of a few hours or tens of hours before it fails. But since we have operated for 100,000 hrs without having a failure, the likelihood of finding a crack in progress was surely very low, on probability alone.

HC,

Since the reason for the cracks has now been determined I would be more suspicious of what has happened since the machines have been siting idle.

Even more reason to clean and eyeball the inside of the VBG shaft.

Just sayin'.

However, the insides of the shafts had previously been cleaned and any corrosion would have been reported (none found) and the helis have not just been sitting about neglectd for the past 9 months, they had the long term storage procedure followed, which includes protecting the "important bits" such as transmission and engines, from corrosion.

Anyway, I'm not saying the inspections shouldn't have been done, just that it was highly unlikely that a problem would have been found (highly unlikely, as in beyond the bounds of possibility!)

And if you run it every 7 days , there is no anti det to be carried out. Most companies cannot afford to let a multi million pound investment sit corroding.

You're not allowed to let it sit corroding, or if you did, it would be very expensive to ever be able to fly it again!

I know this thread is primarily about the 225s that have sat idle since the grounding, but what about the ones in Vietnam and China that have been flying all through the grounding of the others.

I understand there have been no issues with them during this time.

Kiwi, no and that is not surprising. Its clear that the 2 ditched aircraft had unusual issues with corrosion. As I keep saying, Bristow with is fleet of 17 or so EC225s have never had this problem and so its fairly unlikely to occur for an operator with a relatively small fleet. Of course "fairly unlikely" isn't good enough and so naturally I welcome the various measures recently announced that will take "fairly unlikely" back down to the levels of safety required for certification.

HC,

So the sludge and moisture were apparently "unusual" and for some reason you are entirely happy that the BRS fleet is not affected.

So what is the real story then or can't it be told.

Terminous......if you cannot grasp the humor....that is your personal problem.....and nothing anyone says to you can convey the humor. Sadly...you either get it or you don't....it has nothing to do with religion....and everything to do with plain old commonsense.

Apparently you have a deficit of that or you would have tweaked to what was being said.

I am so disheartened you cannot appreciate good humor when it is offered.

Let's just say....i find you thicker than two short planks if you fail to see what is humorous about the joke being made.

Lighten up Dude.....relax.....chill out.... seek comedy in your life....and find a way to see humor in every day situations......after all the best humor is based upon every day life.

For sure....if you cannot laugh at yourself....there is no hope for your Soul.

Anyone that is so thick as not to see the funny side of what was posted.....needs a re-think on life's varied perspectives.

Damn fella, I sent you three helicopters and two boats......what were you waiting on? As a famous American Comedian would opine....."Here's yer Sign!"!

There was some serious thought in that post you cannot fathom!

And Sasless I find that generally, you have too much to say for yourself and are somewhat pompous.

RVDT, if its ever been explained why the CHC shaft had an uniquely large amount of sludge its passed me by. But since you are big on conspiracy theories I suspect its down to those aliens that landed at Rosewell.

HC,

Not a conspiracy - just an open mind on safety and no googles painted on the inside to impair the vision!

All will be revealed one day I hope.

RVDT,

At the presentations in Aberdeen by EC to all operators, it was explained that this particular CHC aircraft not only had high gearbox hours, but had spent more time than any others shut down offshore (and overnight, but not 100% sure).

Therefore there were frequent cycles of cooling and condensation combined with particles from wear on the spline to build up "mud" more thickly and for a far longer period than any other 225 in service.

The conditions for stress corrosion could not have been greater. A CHC engineer who was present stated that other CHC 225s had also been working in similar conditions, although for not nearly as long.

Colibri49,

Thanks for that. Now we have a better idea all round.

So the chc machine was old and high hours but the bond machine was new and low hours.....
I presume all the bristow machines are not old, not new, not high or low hours just in sweet safe spot then?

You really don't know when to quit do you?

Lowfat, not quite sure where your last sentence comes from (other than a desire to be rude for the sake of it) so I'll ignore it.

The Bond aircraft was new and had a slightly modified shaft with the reprofiled hole. Fortunately no Bristow aircraft had that mod state of shaft.

The CHC aircraft, as has just been explained, had unusual operating conditions which (may) have accounted for its corrosion. it had relatively high hours on the gearbox, but so do plenty of ours. But anyway, for whatever reason, it had much more corrosion than any other 225.

Make of all that what you will, but those are the simple facts.

That's the bit I have been looking for - "the whatever reason".

I hope ECF know what the "whatever reason" is. :ugh:

Well Colibri seems to know the reason given. Even if its an incorrect guess on the part of EC, it doesn't matter because the changes to the maintenance programme and the relocated oil jets will ensure it doesn't happen again.

Which event won't happen again? the sludge or the crack?

The sludge build up wont happen again, therefore the crack won't happen again. Unless of course another reason for failure comes out of the woodwork, but that seems highly unlikely with all the time spent on researching it.

Lowfat, I can't remember if you are (were) a 225 pilot? If so, are you nervous at the thought of flying it again, because you are coming across very negative.

I have considerable experience of Eurocopter and their fixes. I have no concerns about flying in 225s

.

Regards
Aser