North Sea Helicopter ditching 10th May 2012
Join Date: Jan 2002
Location: Aberdeen
Posts: 1,234
Likes: 0
Received 0 Likes
on
0 Posts
HC - you are perfectly correct in that the recent crashes have been from the cruise. However when you look at all the data that is not the case.
There is certainly a little bit of 'playing the numbers' - particularly in companies internal satistics. This is where we generally only use fatilities in these assessments - there is a lot of 'over 3 day injury cases', where the person is allocated an office job to avoid the threshold, or his rota is changed to get him off the platform. Etc, etc.
Accidents from the cruise however are particularly worrying as they typically have a much higher death rate (proportion of the passengers killed) than those which occur during takeoff and landing (successful ditchings aside!).
Which is partially why I have been so interested in the recent gearbox incidents. In all aircraft 'the middle' bit is typically the safest part of the flight - the risks are collision of all types and mechanical failures and sometimes weather related stuff like AF447. The 'end bits' rely upon procedures, facilities, weather, pilots' abilities and the mechanical bits and so are not surprisingly more risky. So when the tradionally 'safer' part of the flight is compromised by design and/or manufacturing and/or maintenance issues the whole thing starts to look a bit shaky.
And so we have accident statistics which for the newer types of aircraft are no better than those they replaced - but the causative factors point much more to design than operation.
There is certainly a little bit of 'playing the numbers' - particularly in companies internal satistics. This is where we generally only use fatilities in these assessments - there is a lot of 'over 3 day injury cases', where the person is allocated an office job to avoid the threshold, or his rota is changed to get him off the platform. Etc, etc.
Accidents from the cruise however are particularly worrying as they typically have a much higher death rate (proportion of the passengers killed) than those which occur during takeoff and landing (successful ditchings aside!).
Which is partially why I have been so interested in the recent gearbox incidents. In all aircraft 'the middle' bit is typically the safest part of the flight - the risks are collision of all types and mechanical failures and sometimes weather related stuff like AF447. The 'end bits' rely upon procedures, facilities, weather, pilots' abilities and the mechanical bits and so are not surprisingly more risky. So when the tradionally 'safer' part of the flight is compromised by design and/or manufacturing and/or maintenance issues the whole thing starts to look a bit shaky.
And so we have accident statistics which for the newer types of aircraft are no better than those they replaced - but the causative factors point much more to design than operation.
Join Date: Mar 2009
Location: St. John's, Newfoundland
Age: 54
Posts: 178
Received 0 Likes
on
0 Posts
Interesting configuration madzadriver, only issue with an offshore access system (OAS) such as deployed on the Smit Kamara is that it is unsuitable for our installations over here i.e. Hibernia is a concrete GBS with no spider deck to cellar deck access, and the other two installations are FPSOs. Drilling platforms such as the semi-submersibles we use over here would also have limited options.
Brings back memories of the "flotels" that we used back in the offshore hook-up days and the bridges that sometimes didn't lift or fell over the side.
I can see this system being of benefit in older jacket design areas, especially in the Gulf of Guinea and offshore Malaysia, where they currently use Billy Pugh and rope swings (seriously, we swing on a rope over to the platform!).
Helo transfer for many reasons is still the preferred option, but recently it seems that there is more emphasis in skewing the stats to justify the decision to keep flying a/c with IMHO base design errors and/or manufacturing defects. It was mis-interpretation of the Waldron report that was the root cause failure mode of Cougar 491 i.e. galled titanium studs, but other factors such as increased filter changeouts due to filter bypass pop-up activation were also factors.
Are we too reliant on HUMS and its interpretation these days, G-REDL is an example of where IMO we were partly let down by reliance on this monitoring technique i.e. redeployment of the accelerometers and subsequent invalidity of 1st stage epicyclic bearing monitoring until the software was updated.
I'm a layman, so for me if you find a defective component and trace its failure mode to a mechanical defect then you replace those suspect parts, not rely on data that may or may not be 100% accurate. If that part just happens to not be readily available and will have a detrimental impact on a/c availability to the operators, then so be it.
Safe flying
Max
Brings back memories of the "flotels" that we used back in the offshore hook-up days and the bridges that sometimes didn't lift or fell over the side.
I can see this system being of benefit in older jacket design areas, especially in the Gulf of Guinea and offshore Malaysia, where they currently use Billy Pugh and rope swings (seriously, we swing on a rope over to the platform!).
Helo transfer for many reasons is still the preferred option, but recently it seems that there is more emphasis in skewing the stats to justify the decision to keep flying a/c with IMHO base design errors and/or manufacturing defects. It was mis-interpretation of the Waldron report that was the root cause failure mode of Cougar 491 i.e. galled titanium studs, but other factors such as increased filter changeouts due to filter bypass pop-up activation were also factors.
Are we too reliant on HUMS and its interpretation these days, G-REDL is an example of where IMO we were partly let down by reliance on this monitoring technique i.e. redeployment of the accelerometers and subsequent invalidity of 1st stage epicyclic bearing monitoring until the software was updated.
I'm a layman, so for me if you find a defective component and trace its failure mode to a mechanical defect then you replace those suspect parts, not rely on data that may or may not be 100% accurate. If that part just happens to not be readily available and will have a detrimental impact on a/c availability to the operators, then so be it.
Safe flying
Max
Join Date: Nov 2011
Location: NL
Posts: 28
Likes: 0
Received 0 Likes
on
0 Posts
Well Max, as an offshore pilot, I'm not surprisingly NOT a fan of the OAS approach, but in the interests of a balanced discussion I thought I should post the info! I believe Shell have some interest in developing their use for offshore shuttling for the future, but nothing confirmed last time I heard.
Last edited by mazdadriver; 22nd May 2012 at 14:19.
Join Date: Apr 2008
Location: Accra
Posts: 54
Likes: 0
Received 0 Likes
on
0 Posts
crew changing by ship is a logistical no go, firstly supply vessels only have bed capacity for say 20 pax, thats immediately a factor if the vessel has to sit tight in weather as is often the case in the NNS, secondly half the older platforms dont have the required safety features on the cranes (double braking system) to routinely perform basket transfers.
For the amount of vessels that would be required to service an industry operating predominantley 2/3 rota programmes the north sea would look like a sunday boating pond and be coloured orange with the non ending waves of sea sickness being produced............its not even factored in the equation now or we would not have had period of being stuck for 4 or 5 days due to Wx or fog (however if you made it half way to lerwick it was happy days)
As for statistics, well they are as good as whats put into the machine that spits them out, yes they carry value but can also be twisted and misleading.
Fact : Its statistically proven that your more like to have a car accident if your 18 - 22 years, male, wearing underwear and driving during the day......so whats the answer......knickers off on the road, stats watch how you use them.
For the amount of vessels that would be required to service an industry operating predominantley 2/3 rota programmes the north sea would look like a sunday boating pond and be coloured orange with the non ending waves of sea sickness being produced............its not even factored in the equation now or we would not have had period of being stuck for 4 or 5 days due to Wx or fog (however if you made it half way to lerwick it was happy days)
As for statistics, well they are as good as whats put into the machine that spits them out, yes they carry value but can also be twisted and misleading.
Fact : Its statistically proven that your more like to have a car accident if your 18 - 22 years, male, wearing underwear and driving during the day......so whats the answer......knickers off on the road, stats watch how you use them.
Join Date: Dec 2009
Location: in my house
Posts: 118
Likes: 0
Received 0 Likes
on
0 Posts
If that part just happens to not be readily available and will have a detrimental impact on a/c availability to the operators, then so be it.
Join Date: Mar 2009
Location: St. John's, Newfoundland
Age: 54
Posts: 178
Received 0 Likes
on
0 Posts
I hear you Iron, these parts most definitely don't just come off the shelf...
I guess that this is where HUMS can really show its benefit via type-proving each critical component, in this case the shaft in question. With two key indicators, namely MOD-45 and MOD-70, the manufacturer is obviously confident in early diagnosis via monitoring.
I'm curious now as to how many AS332 types have similar bevel gear shafts and why they were not included in the EASA AD. I can only assume that the shafts with proven TIS records are by default deemed airworthy. However, how many shafts have been changed out over the years and are any of the suspect ones still in use?
For me over here we only use S92s these days, so we have our own problems!
Safe flying
Max
I guess that this is where HUMS can really show its benefit via type-proving each critical component, in this case the shaft in question. With two key indicators, namely MOD-45 and MOD-70, the manufacturer is obviously confident in early diagnosis via monitoring.
I'm curious now as to how many AS332 types have similar bevel gear shafts and why they were not included in the EASA AD. I can only assume that the shafts with proven TIS records are by default deemed airworthy. However, how many shafts have been changed out over the years and are any of the suspect ones still in use?
For me over here we only use S92s these days, so we have our own problems!
Safe flying
Max
Up to the failure of the shaft in question....everyone was happy that the monitoring system in place at that time would detect any failures too.
With the changes made as a result of the shaft failure....I guess we should be all happy with the situation now.....right?
One Man's opinion here....as a Pilot...not an Engineer....but I would prefer the testing be done in a Clean Room rather than the aircraft I am flying.
Am I being a Scaredy Cat here?
With the changes made as a result of the shaft failure....I guess we should be all happy with the situation now.....right?
One Man's opinion here....as a Pilot...not an Engineer....but I would prefer the testing be done in a Clean Room rather than the aircraft I am flying.
Am I being a Scaredy Cat here?
Join Date: Jan 2002
Location: Aberdeen
Posts: 1,234
Likes: 0
Received 0 Likes
on
0 Posts
No you're not being a scaredy cat!
One of the major problems with the latest design codes (not just in aviation but also in my area of offshore O&G), it that they allow manufacturers to produce designs which are supposedly based on a reliability assessment. The infamous 1 x 10-9 failure criteria. As a concept it is fine - the failure is that obviously it is based upon 'engineering' estimates. So the manufacturer designs something new and does some testing. With luck that will be a couple of hundred hours, maybe even a couple of thousand - but obviously seriously short of 1 billion. His people then extrapolate that using the data from a different design. Hey presto it is certified.
Then it gets into service and much like software we all become beta testers.
Unfortunately extrapolating from very short periods of testing is horribly inaccurate - and manufacturers never give products the sort of treatment they get in the field.....
One of the major problems with the latest design codes (not just in aviation but also in my area of offshore O&G), it that they allow manufacturers to produce designs which are supposedly based on a reliability assessment. The infamous 1 x 10-9 failure criteria. As a concept it is fine - the failure is that obviously it is based upon 'engineering' estimates. So the manufacturer designs something new and does some testing. With luck that will be a couple of hundred hours, maybe even a couple of thousand - but obviously seriously short of 1 billion. His people then extrapolate that using the data from a different design. Hey presto it is certified.
Then it gets into service and much like software we all become beta testers.
Unfortunately extrapolating from very short periods of testing is horribly inaccurate - and manufacturers never give products the sort of treatment they get in the field.....
Then it gets into service and much like software we all become beta testers.
So yes a new model of anything, especially a helicopter, will always have issues, some more scary than others.
Although the focus is on the 225 at the moment, one of its strengths is that it is an evolution of previous proven designs, changes only being made when there is a clear benefit. The bevel shaft design concept has always been fine until they decided for some reason to change the manufacturing process (and possibly had slackened the quality control).
By contrast the S92 is more of an all-new less-proven design (Black Hawk legacy not withstanding) and it has had far more and various major design failures as a consequence.
Bottom line is that the bathtub curve is the reality. 7 years or so down the road, on both these new types we are getting down towards the bottom of the steep bit of the curve with only 1 fatal accident between both. That is probably quite a good record!
So yes, new types bring greater risk of techincal / design issues. However newer types are also much easier and safer to fly from an operational point of view (if correct procedures are established and followed) so it is swings and roundabouts with the safety of new types!
HC
I see there is a new AD out concerning the affected shafts. Apart from putting the M'ARMS download interval up to 4 hrs, there are some rather odd other constraints.
The AD only applies to helicopters operated over water at night or in IMC.
If the M'ARMS is unservicable, the heli can still be operated over water but has to be placarded "Day VFR only for flights over water".
Is it just me, or is it pointless to make the differentiator flight in IMC, rather than anything relating to survivability following ditching. If flying in IMC over flat water, this does not impede safe ditching (surface fog excepted). But a wild sea state certainly does.
Similarly if flying in mountainous terrain with cloud down to the surface, you would be vey badly placed to have to make an emergency landing, but the AD doesn't care about that.
Is there anyone in EASA who understands anything about helicopter ops?
The AD only applies to helicopters operated over water at night or in IMC.
If the M'ARMS is unservicable, the heli can still be operated over water but has to be placarded "Day VFR only for flights over water".
Is it just me, or is it pointless to make the differentiator flight in IMC, rather than anything relating to survivability following ditching. If flying in IMC over flat water, this does not impede safe ditching (surface fog excepted). But a wild sea state certainly does.
Similarly if flying in mountainous terrain with cloud down to the surface, you would be vey badly placed to have to make an emergency landing, but the AD doesn't care about that.
Is there anyone in EASA who understands anything about helicopter ops?
Press and Journal - Article - Bond cleared of blame for helicopter ditching
Helicopter manufacturer Eurocopter has cleared operator Bond of any blame for a ditching incident in the North Sea last month.
The aviation giant – which built the Super Puma which had to make an emergency landing on the sea off Aberdeen last month – said Bond was not responsible for the accident.
Two crew and 12 passengers had to be rescued in what was the third serious incident involving a Bond Super Puma in three years.
Eurocopter said the skill of the Bond pilots and the design of the aircraft saved their lives.
The aviation giant – which built the Super Puma which had to make an emergency landing on the sea off Aberdeen last month – said Bond was not responsible for the accident.
Two crew and 12 passengers had to be rescued in what was the third serious incident involving a Bond Super Puma in three years.
Eurocopter said the skill of the Bond pilots and the design of the aircraft saved their lives.
Apart from putting the M'ARMS download interval up to 4 hrs, there are some rather odd other constraints
I agree the other criteria are nonsensical.......
4 hrs is better than the 3 hrs it was! Fortunately none of our aircraft are affected. 4 hrs is sufficient to do the average NNS trip out of Aberdeen, not up to the Basin though. I suppose those affected have to carry a laptop, download it offshore and hope for green traffic light, else stuck offshore!
On the P&J article I would prefer to wait for the AAIB report before forming an opinion. Bond and EC have a commercial relationship and so the view of EC could not be considered to be impartial. Whilst Bond and EC will be primarily concerned about where the blame lies, and clearly the primary fault is with the shaft manufacture, and clearly all credit to the crew for pulling off a safe ditching, the AAIB will hopefully be more impartial and may identify ways that the fault could have been picked up earlier (or maybe not) which may allow us all to learn how to prevent a recurrence. It might or might not show that operators who downloaded their HUMS data more frequently would have caught the problem.
On the P&J article I would prefer to wait for the AAIB report before forming an opinion. Bond and EC have a commercial relationship and so the view of EC could not be considered to be impartial. Whilst Bond and EC will be primarily concerned about where the blame lies, and clearly the primary fault is with the shaft manufacture, and clearly all credit to the crew for pulling off a safe ditching, the AAIB will hopefully be more impartial and may identify ways that the fault could have been picked up earlier (or maybe not) which may allow us all to learn how to prevent a recurrence. It might or might not show that operators who downloaded their HUMS data more frequently would have caught the problem.
You really make me laugh...
You profess wait and and see for a unbiased report and snipe with your last comment about the frequency of the HUMS download. In fact most if not all of your comments on this subject are thinly disguised cheap shots. Take your own advise stop posting PR and wait for the official report.
Its like Son of SHELL MANAGEMENT.
You profess wait and and see for a unbiased report and snipe with your last comment about the frequency of the HUMS download. In fact most if not all of your comments on this subject are thinly disguised cheap shots. Take your own advise stop posting PR and wait for the official report.
Its like Son of SHELL MANAGEMENT.
You really make me laugh...
You profess wait and and see for a unbiased report and snipe with your last comment about the frequency of the HUMS download. In fact most if not all of your comments on this subject are thinly disguised cheap shots. Take your own advise stop posting PR and wait for the official report.
Its like Son of SHELL MANAGEMENT.
You profess wait and and see for a unbiased report and snipe with your last comment about the frequency of the HUMS download. In fact most if not all of your comments on this subject are thinly disguised cheap shots. Take your own advise stop posting PR and wait for the official report.
Its like Son of SHELL MANAGEMENT.
lowfat - I can understand that if you work for Bond you are deperate for some absolution. But for the rest of us, learning any lessons is more important than trying to hide them in case they are damning.
If it is any consolation, if I had to put money on it my best guess would be that with the thresholds set as they were, even if RRTR download had been carried out I doubt an amber or red traffic light would have been generated. And anyone who knows about the practicalities of HUMS knows that it is not feasible for engineering to manually trawl through every parameter of every transmission element looking for some unusual trend.
However that is only my guess. If I were Bond I would be nervous about crowing about absolution until it is "official" just in case it turned out to be incorrect. In aviation it is seemly to be open to the possibility of having made a mistake and hence open to learning from it and applying a fix. To have as your first priority a desire to prove lack of blame is I suppose understandable from a commercial point of view but not from an aviation safety point of view.
Despite your feelings about me I do hope that Bond are proven to be absolved, but so far that can only be a hope.
If it is any consolation, if I had to put money on it my best guess would be that with the thresholds set as they were, even if RRTR download had been carried out I doubt an amber or red traffic light would have been generated. And anyone who knows about the practicalities of HUMS knows that it is not feasible for engineering to manually trawl through every parameter of every transmission element looking for some unusual trend.
However that is only my guess. If I were Bond I would be nervous about crowing about absolution until it is "official" just in case it turned out to be incorrect. In aviation it is seemly to be open to the possibility of having made a mistake and hence open to learning from it and applying a fix. To have as your first priority a desire to prove lack of blame is I suppose understandable from a commercial point of view but not from an aviation safety point of view.
Despite your feelings about me I do hope that Bond are proven to be absolved, but so far that can only be a hope.
Even with this sanctimonious reply you are forgetting
"There but for the grace of God, go I"
As you appear to blow the trumpet of Bristows all the time lets learn the lessons of the Bristow Nigeria Ditching in December 2009.
http://www.pprune.org/rotorheads/398...g-nigeria.html
Oh sorry that s right..
It has none
there is no report ..... It would appear to have been swept under the carpet.....
Notice you didn't post on that thread with your expert analysis.
Taxi for Helicomparetor!
"There but for the grace of God, go I"
As you appear to blow the trumpet of Bristows all the time lets learn the lessons of the Bristow Nigeria Ditching in December 2009.
http://www.pprune.org/rotorheads/398...g-nigeria.html
Oh sorry that s right..
It has none
there is no report ..... It would appear to have been swept under the carpet.....
Notice you didn't post on that thread with your expert analysis.
Taxi for Helicomparetor!
Whatever did happen to the report on the Nigeria ditching....and all the video that was taken...especially the part where the Co-Pilot was talking of what happened?
Can you enlighten us HC? Surely there was some sort of NCAA investigation and a Investigative Report issued....wasn't there?
My post in the Nigeria Puma Ditching thread......
Can you enlighten us HC? Surely there was some sort of NCAA investigation and a Investigative Report issued....wasn't there?
My post in the Nigeria Puma Ditching thread......
Still no official word on the latest Accident in Nigeria?
But then as there has been no Press Releases providing any details of the Two Bell 412's that were lost either....this should come as no surprise.
One 412 went down at night during a very questionable set of circumstances while on a "Casevac" flight killing all aboard.
The second 412 crashed at the Mobil QIT....under really odd circumstances killing the only occupant aboard....the pilot.
Now we have a Tiger going for a swim.....and despite there being no one injured and at least one video tape in existence.....still no report telling of the circumstances.
Makes one wonder why the zipped lips!
Bristow using Polygraphs and Voice Analysers to seek out "Leakers"?
Beware the key stroke monitoring programs on the company router perhaps....but when at home on leave....one should be able to spread a bit of word to the rest of us.
But then as there has been no Press Releases providing any details of the Two Bell 412's that were lost either....this should come as no surprise.
One 412 went down at night during a very questionable set of circumstances while on a "Casevac" flight killing all aboard.
The second 412 crashed at the Mobil QIT....under really odd circumstances killing the only occupant aboard....the pilot.
Now we have a Tiger going for a swim.....and despite there being no one injured and at least one video tape in existence.....still no report telling of the circumstances.
Makes one wonder why the zipped lips!
Bristow using Polygraphs and Voice Analysers to seek out "Leakers"?
Beware the key stroke monitoring programs on the company router perhaps....but when at home on leave....one should be able to spread a bit of word to the rest of us.
Last edited by SASless; 16th Jun 2012 at 12:54.
lowfat - since you just want to be abusive and are not interested in any facts or opinions except your own - especially if they might be truthful, maybe you should go back to moo moo land and give the moaning mooing a break. Do you think trying to create a smokescreen with an old nigerian accident in some way takes the heat off you? Shame on you for not being interested in the truth.
SAS - good question about the Nigerian 332 ditching. Of course we know what happened (though not necessarily exactly why), but I have never seen a report. There would not be a report from AAIB because it would be the Nigerian equivalent investigation board. I presume there must be such a thing but personally I have never come across a report of an aviation accident in Nigeria. A quick Google reveals nothing so I guess it must be well hidden!
SAS - good question about the Nigerian 332 ditching. Of course we know what happened (though not necessarily exactly why), but I have never seen a report. There would not be a report from AAIB because it would be the Nigerian equivalent investigation board. I presume there must be such a thing but personally I have never come across a report of an aviation accident in Nigeria. A quick Google reveals nothing so I guess it must be well hidden!
Last edited by HeliComparator; 16th Jun 2012 at 13:32.