North Sea heli ditching: Oct 2012
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How is the EC725's affected? Are they also grounded/limited/etc? Have they had any incidences? Just wondering as it could be interesting if they are still flying?
Original RFM Procedure
HC,
The procedure you quoted "verbatim" is missing three items in my copy of the original RFM approved by the FAA 9/11/04:
There were two explanatory notes following the Warning in para 1.
There were two Land Immediately paragraphs, number 3 and 4.
Perhaps there was a revision between the original and the one you quoted?
Thanks,
John
The procedure you quoted "verbatim" is missing three items in my copy of the original RFM approved by the FAA 9/11/04:
There were two explanatory notes following the Warning in para 1.
There were two Land Immediately paragraphs, number 3 and 4.
Perhaps there was a revision between the original and the one you quoted?
Thanks,
John
John, possibly. When I cut that out in 2005 I didn't cut anything from within the quoted area, so perhaps your bits are outside the quoted area? But if within, I would say there must have been a revision in the mean time
Sevarg, no hopefully not like the Chinooks. They died because of the fundamental design issue ie intermeshing rotors, plus a lot of deaths. The 225 has yet to kill anyone and if you are a passenger, I suspect that is the major consideration.
Sevarg, no hopefully not like the Chinooks. They died because of the fundamental design issue ie intermeshing rotors, plus a lot of deaths. The 225 has yet to kill anyone and if you are a passenger, I suspect that is the major consideration.
Last edited by HeliComparator; 25th Nov 2012 at 14:54.
Odd.....the old girls are still flogging the skies around the World with fleet hours in the Millions....and a safety record as good as any other helicopter. The North Sea machines that got flogged off are still out there earning a living hauling massive loads all day long for Columbia.
You suppose if the Brits had listened to those who had operated the things for decades before the first one arrived in Blighty....things might have gone a bit differently? I should think the continuing success of the Chinook in other parts of the World and the RAF.....should confirm the validity of the design.
Some folks just have a narrow minded view of things.
You suppose if the Brits had listened to those who had operated the things for decades before the first one arrived in Blighty....things might have gone a bit differently? I should think the continuing success of the Chinook in other parts of the World and the RAF.....should confirm the validity of the design.
Some folks just have a narrow minded view of things.
They died because of the fundamental design issue ie intermeshing rotors, plus a lot of deaths
Last edited by SASless; 25th Nov 2012 at 15:03.
Well if the two 225 ditchings had happened in different sea states without S+R close at hand they may well have killed a lot of good folks.
I put that down to good piloting skills, adherence to check lists, and more than a little bit of luck.
I don't think that the passengers are comforted to any great extent just because of the good outcome of events in the two cases.
"In part the spotlight was less bright because these events didn't happen in CAA-land." Come on HC that's a little bit over the top don't you think! Not all of us work in CAA land and the CAA is not the be all and end all of helicopter safety.
I put that down to good piloting skills, adherence to check lists, and more than a little bit of luck.
I don't think that the passengers are comforted to any great extent just because of the good outcome of events in the two cases.
"In part the spotlight was less bright because these events didn't happen in CAA-land." Come on HC that's a little bit over the top don't you think! Not all of us work in CAA land and the CAA is not the be all and end all of helicopter safety.
Last edited by albatross; 25th Nov 2012 at 15:23.
albatross, yes the sea states were good but they have to be pretty bad before fatalities become probable rather than possible. There are certainly such days but the vast majority of days are not like that. And as I said, exactly the same applies to other type's non-catastrophic events resulting in "Land Immediately"
92 RFM
No, HC, they were in that section of para. 7.1 that begins with: " If the MGB OIL PRESS warning light illuminates...
The second Land immediately action, sub para 4 within the section you quoted, is the last entry in the general para. 7.1.
Thanks,
John
The second Land immediately action, sub para 4 within the section you quoted, is the last entry in the general para. 7.1.
Thanks,
John
A quick google search on "helicopter ditching statistics":
http://ftp.rta.nato.int/public//PubF...HFM-152-05.pdf
Interesting read amongst many others.
Of course we know that are "Lies, damned lies and statistics" LOL
Interesting thread - I think we may be headed for a record number of pages.
Cheers
Albatross
http://ftp.rta.nato.int/public//PubF...HFM-152-05.pdf
Interesting read amongst many others.
Of course we know that are "Lies, damned lies and statistics" LOL
Interesting thread - I think we may be headed for a record number of pages.
Cheers
Albatross
albatross, as far as I can tell that doc doesn't really distinguish between intentional controlled ditching, and accidentally flying into the water. At first glance, that devalues the research in my eyes.
Albatross, I have seen this document quoted a number of times and as HC highlights, it does not limit itself to controlled ditchings in reaching the supposed survival rates. I would go so far as to say the document is dangerous, as it does not present pilots with the true risks associated with a controlled landing on water.
I have always wondered if the Captain of the Cougar aircraft, who ignored the Land Immediately situation the aircraft was in, had seen this document and these statistics were part of his decision making process?
A quick aside - HC, the S92 RFM I was referencing for my earlier response was dated November 2005, obviously an amendment after the incident you are referring to.
I have always wondered if the Captain of the Cougar aircraft, who ignored the Land Immediately situation the aircraft was in, had seen this document and these statistics were part of his decision making process?
A quick aside - HC, the S92 RFM I was referencing for my earlier response was dated November 2005, obviously an amendment after the incident you are referring to.
Good point guys.
I wonder also if those stats influenced the crew off of NFLD.
The weather/ sea state and temperature at the time was far from ideal.
I found another site in my quick search that posted some truly horrific stats which I will not quote here as they seem more scare mongering than anything else.
Like anything else on the internet the application of a little bit of salt is required.
Cheers
Albatross
I wonder also if those stats influenced the crew off of NFLD.
The weather/ sea state and temperature at the time was far from ideal.
I found another site in my quick search that posted some truly horrific stats which I will not quote here as they seem more scare mongering than anything else.
Like anything else on the internet the application of a little bit of salt is required.
Cheers
Albatross
Seems the 225 is doing that salt thing really well!
The stats do force us to consider the effect Sea State, Water Temp, Amount of natural light (Day-Night), Visibility, and response time of SAR in their effect upon Air Crew Decision making.
Ditching in the Bahamas is not the same as ditching north of Deadhorse or in the North Sea or off Newfoundland.
The stats do force us to consider the effect Sea State, Water Temp, Amount of natural light (Day-Night), Visibility, and response time of SAR in their effect upon Air Crew Decision making.
Ditching in the Bahamas is not the same as ditching north of Deadhorse or in the North Sea or off Newfoundland.
Last edited by SASless; 25th Nov 2012 at 17:41.
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HC
But sadly the passengers never did like it much and now don't want to go near it. My company is being pressured to replace them with 92s, memories are short it seems. But, the 92 has been doing better recently.
Yes I am saddened to see the 225 taking a beating because I know just what a good aircraft it is, always accepting that all helis have their issues including this one! But those specific issues aside, it is overall a really good pilot's machine with better range/payload than the competition.
Last edited by terminus mos; 25th Nov 2012 at 20:36.
terminus, there are also plenty of stories of passengers routinely using the 92 not liking it either. Let's face it, the offshore community just don't like any helicopters, and why should they when we scare them sh**less by showing them scary videos before each flight!
I suspect it is "grass is greener" but no less unfortunate for the future of the 225 at least in the short term.
I suspect it is "grass is greener" but no less unfortunate for the future of the 225 at least in the short term.
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Yes. Right on! I vote for a new shaft without any weld, except that it would take years to certify.
While EC apparently seems comfortable with EB/laser welding finished gear shafts, I know that other transmission OEMs prefer not to use this approach. The problem is that since the weld is performed after heat treatment of the gear, the metallurgical properties in the weld HAZ (heat affected zone) will remain in the as-welded condition, which is not optimum. The weld HAZ cannot be improved even with a thermal stress relief and normalization cycle.
If the reports of weld failures are true, even if EC retains the welded shaft design (with any necessary design changes) then there will still be a lengthy re-qualification process. Since the gear shaft is a flight critical component, the weld process itself and any post weld QA procedures (such as NDI, etc.) must also be re-qualified.
I appreciate why EC chose to use a welded bevel gear shaft design. And that is because it is definitely lighter than the conventional 2-piece mechanically fastened design approach, as well as being less expensive. However, there is a very good reason many OEMs still use the 2-piece design, and that is because it is very difficult in a production environment to ensure the extremely high quality levels needed in the welds.
Here is a link to a drawing of an older MGB design (I believe it's a Huey MGB) that has a similar layout to the EC225, with a spiral bevel input gear stage. You can see how the spiral bevel gear is mechanically fastened to the shaft. While it may seem counter-intuitive, from an overall fault-tolerance standpoint this design is actually better than the EB/laser welded design. Since it is an easier QA task to verify the correct installation of fasteners than it is to verify the integrity of an EB/laser weld joint.
Very interesting discussion! I've even learned a few new things.
riff raff
As before, your explanations make perfect sense and strengthen my first gut reaction in the days after the May 2012 ditching when I was astonished to learn that welding gets used in such an application. To put it simply "It just don't seem right".
This part of the EC225 gearbox is probably approaching the limit of horsepower/torque/vibration stresses that this latest version of the Super Puma family can tolerate. Something changed in recent times, perhaps caused by V12 software, to push things just beyond that limit, I guess.
But I very much wish to see the EC225 back in business soon. So if my whacky idea of threading and screwing the shaft sections together is a non-starter, what about the suggestion from jimf671 "Long bolting could be worth a look" ?
Not only would this clamp the lower shaft section safely in place, but it seems to me that it would create two redundant load paths; the weld and the long bolt. I like "belts and braces" as a principle.
As before, your explanations make perfect sense and strengthen my first gut reaction in the days after the May 2012 ditching when I was astonished to learn that welding gets used in such an application. To put it simply "It just don't seem right".
This part of the EC225 gearbox is probably approaching the limit of horsepower/torque/vibration stresses that this latest version of the Super Puma family can tolerate. Something changed in recent times, perhaps caused by V12 software, to push things just beyond that limit, I guess.
But I very much wish to see the EC225 back in business soon. So if my whacky idea of threading and screwing the shaft sections together is a non-starter, what about the suggestion from jimf671 "Long bolting could be worth a look" ?
Not only would this clamp the lower shaft section safely in place, but it seems to me that it would create two redundant load paths; the weld and the long bolt. I like "belts and braces" as a principle.
Last edited by Colibri49; 26th Nov 2012 at 08:36. Reason: To improve phraseology
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ALBATROSS - your comment about luck alluding to the forced landings in calm sea states is not an accurate reflection of the Puma design's inherent ability to float. Throughout this issue I have come across a couple of good images of Pumas floating quite happily in fairly unpleasant sea states. One in the Norwegian sector and Bristows Tiger after the lightening strike. (I think the Tiger rolled over only after the salvage boat stabbed the floats).
It floats low in the water but it does seem to float well so I do not think your point is valid.
DB
It floats low in the water but it does seem to float well so I do not think your point is valid.
DB
Attempt to sort out IB db update failure
Well years ago I had the engine of a Bell 206L self destruct in a most unexpected and spectacular manner.
I had just spent 40 minutes inserting crews into 3 confined areas in the bush and had just departed camp to return to the area with the second crew over unbroken forest and small lakes.
When Mr. Turbine resigned I just happened to be nearly overhead an abandoned sandpit into which I was able to do a successful 270 auto thanks to the 206L doing that so well.
In my case I call that luck - 206 auto rotational capabilities and the good training I had received notwithstanding.
When I refer to luck in this case I call the good sea state and proximity of rescue vessels the same thing.
I in no way try to take away from the professional conduct of the crews or the seaworthiness of the 225 when ditched.
I just think that it could just as easily have happened to another aircraft, elsewhere, in a worse environment. Hence luck, fate whatever you want to call it playing a roll.
I had just spent 40 minutes inserting crews into 3 confined areas in the bush and had just departed camp to return to the area with the second crew over unbroken forest and small lakes.
When Mr. Turbine resigned I just happened to be nearly overhead an abandoned sandpit into which I was able to do a successful 270 auto thanks to the 206L doing that so well.
In my case I call that luck - 206 auto rotational capabilities and the good training I had received notwithstanding.
When I refer to luck in this case I call the good sea state and proximity of rescue vessels the same thing.
I in no way try to take away from the professional conduct of the crews or the seaworthiness of the 225 when ditched.
I just think that it could just as easily have happened to another aircraft, elsewhere, in a worse environment. Hence luck, fate whatever you want to call it playing a roll.
Last edited by albatross; 26th Nov 2012 at 14:53.
Yet....does not the UK CAA encourage "Side Mounted" flotation to ensure the helicopter stays at least mostly upright? The majority of drownings post-ditching/crashes comes from the aircraft rolling over and filling with very cold water.
I know they did lots of expensive testing to confirm that notion.
I know they did lots of expensive testing to confirm that notion.