EC225 crash near Bergen, Norway April 2016
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To assist Birmingham,
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
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To assist Birmingham,
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
Thank you.
Very helpful
I am sickened to the stomach that in 2016 and 50 years since we started extracting oil in the NS, that we should still be having these all too frequent tragic losses of life.
I understand that there is an element of risk with any aircraft; after-all, there are so many things that could theoretically go bang. But my question is this: would the operators allow this frequency of failure or this level of calculated risk on a well-head or a production facility?
I understand that there is an element of risk with any aircraft; after-all, there are so many things that could theoretically go bang. But my question is this: would the operators allow this frequency of failure or this level of calculated risk on a well-head or a production facility?
there is an unacceptable frequency to any chopper incident in this industry, which I cannot help but feel that if such incidents were to directly impact production/revenue, they genuinely wouldn't happen ever again.
In a rotary winged aircraft, there are certain lethal "single points of failure" that are inherent in the beast. Because of their criticality, they have to be designed with a higher safety factor than a lot of other parts. (alby3z says it better in the post following this one). Major parts like the rotor mast, the swashplate, rotor blades and blade retention parts (that which holds the blade to the rotor hub) and many others. When one of these breaks under flight loads, other things break horribly. The laws of physics shall not be flaunted.
What is encouraging is that, over the years, designs more often accommodate something termed "graceful degradation." Example: if the gears start to eat each other, the systems have a way to detect those metal bits in the oil, a light goes on, and pilots have a clue that it's time to get out of the sky before it all comes apart. We've seen a few NS ditchings in the past ten years where the aircraft was lost but all souls recovered. The last 30 years of HUMS, and vibration analysis, has been a boon to catching problems early, before they become big problems. (That particular systemic improvement still has room to grow).
The core problem is that with certain dynamic components it is a binary issue:
on or off
alive or dead.
(Suggested reading topic: Mast Bumping, Bell, Huey (UH-1) 1960's or so. It was a feature of the rotor system design that was potentially lethal, but there were operational means to avoid that occurring and creating a critical failure. When you consider how many thousands of two bladed Hueys have flown, and are still flying, with the underslung semi-rigid rotor system, it is clear that lethal risks can be mitigated procedurally. The same is true for most mature helicopters: over time, the accumulated knowledge of "that'll kill you" has become known and each case has means and methods to prevent it.)
Another family of risk mitigation is in performing maintenance. A non-trivial percentage of that activity is things to check before you fly every time you take the bird up. Exam question: is the bird telling me that a key part is on the way to failure? Systems have been developed and rules crafted, and decision points laid out, to nip those in the bud and not fly the bird until any such condition is corrected. You have to go looking for them before each launch.
With the above considered: until the "why" of this accident comes to light, you can't know which of the safeguards already in place may have been missed and the holes in the Swiss began to line up.
Once the "why" is determined the system as a whole can respond. It will respond one way if it's a novel, first time failure mode, or another way if it's a previously known failure mode.
(I'll take you back to the 1960's again, and a USN A-7 that crashed on a bombing run due to a wrench being left in during maintenance, flight controls binding, and no pull up. The system response to that is still in the USN, in the form of the formal tool control program I was raised with).
Until "why" is cleared up, the "this is unacceptable" line has nothing to build on if you are looking at the whole system and all of its interrelated parts.
Accordingly, I refuse to accept that the downing of a chopper cannot be prevented.
And while accidents do happen,
Thanks for the post and its intention (from the heart).
If you believe, in your heart, that the only standard that you can accept is zero defects, I am not sure that such can be accomplished when looking at the system as a whole. It's a good target to strive for.
Last edited by Lonewolf_50; 26th May 2016 at 02:40.
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To assist Birmingham,
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
The entire weight of the L1/L2/225 is supported on those 3 struts and their associated hardware whilst airborne.
The rear of the engines are effectively supported by the same struts, as they are bolted to the gearbox which is held in position between the top of the struts and the BBQ plate.
The rear of the engines is not a lift path.
The BBQ plate only allows for torque and is not a lift path.
I cannot imagine any scenario where a failure of a lift strut, for any reason, would allow the aircraft to continue flying.
You only have to look at the Norn Incident to see the effect of strut failure (for an identified reason)
I WAS going to say "unconnected" reason but, in fact, there is nothing in the public domain to base that on.
I think that we simply cannot imagine the forces acting on the conical housing and airframe once it all goes wrong - torque, gyroscopic, mechanical, aerodynamic, 1500 shp and 6/7 tonnes, 140 knts.
Ugh.
As per FAR 29.571 any PSE (principal structural element, a failure of which would cause a catastrophic failure), must be substantiated damage tolerant or safe-life. This roughly speaking means that 1)in the damage tolerant case you must show that the element is able to withstand flight loads notwithstanding a failure of prescribed (and controlled) amplitude should occurs, 2) in the safe-life case you must show that the element subjected to loads will not have any failure in the whole operative life.
In other words the possibility to avoid any catastrophic failure is achievable also in case of failure of one component (for sure at high cost in terms of structural redundancy and weight penalty).
Hope this clarify a bit.
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Sanus & tenfour,
Sanus wrote:
"The EC225 is cheaper than an S92. The AW189 is much cheaper than an EC225. There's little doubt that as in life the same applies to helicopters - You get what you pay for"
I think you are mistaken. The EC225 is the most expensive helicopter. Its not a case of Oil companies/operators getting the cheapest choppers to make a saving here.
Sanus wrote:
"The EC225 is cheaper than an S92. The AW189 is much cheaper than an EC225. There's little doubt that as in life the same applies to helicopters - You get what you pay for"
I think you are mistaken. The EC225 is the most expensive helicopter. Its not a case of Oil companies/operators getting the cheapest choppers to make a saving here.
I think you are mistaken. The EC225 is the most expensive helicopter.
The price of S92 vs EC225 also varies depending on exchange rate. Capital cost is almost irrelevant. It's more to do with DOC as far as cost is concerned. The biggest factors are seat cost per mile and payload. Over the longer distance, the 225 seems to win hands down.
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Further to my earlier post and prompted by alby3z' comment.
In the report for the Norne crash the AIB report implies (as I read it) that it is difficult to back date safety standards in design and apply them to older aircraft.
I,m not sure how old the basic design is for the puma series, but I guess that,s why we buy NEW aircraft.
Of course, new aircraft come with new problems.
In the report for the Norne crash the AIB report implies (as I read it) that it is difficult to back date safety standards in design and apply them to older aircraft.
I,m not sure how old the basic design is for the puma series, but I guess that,s why we buy NEW aircraft.
Of course, new aircraft come with new problems.
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Come on now people, is this thread really going to be deflected side ways to talk about the cost of each aircraft. In the grand scheme of things, its operational cost vs payload. Operational cost varies from company to company and includes everything from currency, insurance, salaries to one or two ply toilet paper. Payload and payload requirements are much the same, different for every operation. At the end of the day, for someone to suggest that running a 225 is the "cheap" option and that "you get what you pay for" is well, I'm sorry, an idiotic comment. Right up there with comparing it to mountain climbing equipment!! Really??
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alby3z Thank you very useful background.
lynnx It will be interesting to see whether something to do with the (apparently) missing suspension bar assembly is a symptom or a causal factor. I think that AH's necessarily cryptic (for legal and liability reasons) early statement that the Puma's are safe to fly, led many to infer that there was an obvious primary cause (and one that differed from G-REDL). If the primary cause was that obvious and we could be assured that the risk could be mitigated by the recommended AH precautions, then I think the type would have been cleared to restart flying. The only reason I can think of, for that not being the case, is that the AIBN do not yet believe they have enough evidence to convince a shocked and fearful user base that the likely cause is sufficiently understood at this stage of the investigation. Given the frequency of recent tragedies their caution is understandable. Of course the one fact we do know for certain is that we have experienced another catastrophic structural failure. Finding the primary cause is only one part of the picture when it comes to determining how we go forward with NS helicopter shuttles.
lynnx It will be interesting to see whether something to do with the (apparently) missing suspension bar assembly is a symptom or a causal factor. I think that AH's necessarily cryptic (for legal and liability reasons) early statement that the Puma's are safe to fly, led many to infer that there was an obvious primary cause (and one that differed from G-REDL). If the primary cause was that obvious and we could be assured that the risk could be mitigated by the recommended AH precautions, then I think the type would have been cleared to restart flying. The only reason I can think of, for that not being the case, is that the AIBN do not yet believe they have enough evidence to convince a shocked and fearful user base that the likely cause is sufficiently understood at this stage of the investigation. Given the frequency of recent tragedies their caution is understandable. Of course the one fact we do know for certain is that we have experienced another catastrophic structural failure. Finding the primary cause is only one part of the picture when it comes to determining how we go forward with NS helicopter shuttles.
Last edited by birmingham; 26th May 2016 at 08:56.
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I hope they continue to operate the 225. Find the issue and rectify and prevent this from happening again as far as is reasonably possible. That is the only sensible solution. I get really irritated by those "Scrap the Puma" pages on facebook. Obviously dreamt up by a knee jerk reacting Oil worker for a bunch of likes. Probably the same worker who "wont set foot on one of those death traps again!" but is at the front of the line to get on one at home time....
If they did take the decision to remove the puma from service then ALL the offshore workforce would have to work extended rota patterns to cope with the reduced number of flights... wouldn't take long for the "Re-instate the Puma!" pages to crop up. Probably from the same guy who called to scrap them.
If they did take the decision to remove the puma from service then ALL the offshore workforce would have to work extended rota patterns to cope with the reduced number of flights... wouldn't take long for the "Re-instate the Puma!" pages to crop up. Probably from the same guy who called to scrap them.
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Helicopters in the NS are not getting safer
Kawijet
Unfortunately the numbers in the NS are stark
from when it began in 1976 - 2009 (33 years) there were 6 serious NS accidents costing 63 lives. These were the boom years of NS activity.
from 2009 - 2016 when production was starting to tail off (7 years) there were 6 serious NS accidents costing 33 lives. All Pumas
These rather unhelpful Facebook pages seek simple solutions e.g. If you ban all Puma flights you will reduce Puma death rates by 100% - Can't argue with that but I wouldn't describe as a considered solution to prevent NS helicopter accidents!
Anyone who knows anything about aviation knows this tragic run affecting the Puma could have happened in other types. MGB issues are hardly unique to Pumas and the Pumas's maintenance, operations and many components are often supplied by the same companies as AW, Sikorsky, Bell etc.
However there is a general attitude among today's NS people that everything should get safer - much safer.
Any aspect of the business which is as potentially risky today as in 1976 has a massive problem.
Unfortunately the numbers in the NS are stark
from when it began in 1976 - 2009 (33 years) there were 6 serious NS accidents costing 63 lives. These were the boom years of NS activity.
from 2009 - 2016 when production was starting to tail off (7 years) there were 6 serious NS accidents costing 33 lives. All Pumas
These rather unhelpful Facebook pages seek simple solutions e.g. If you ban all Puma flights you will reduce Puma death rates by 100% - Can't argue with that but I wouldn't describe as a considered solution to prevent NS helicopter accidents!
Anyone who knows anything about aviation knows this tragic run affecting the Puma could have happened in other types. MGB issues are hardly unique to Pumas and the Pumas's maintenance, operations and many components are often supplied by the same companies as AW, Sikorsky, Bell etc.
However there is a general attitude among today's NS people that everything should get safer - much safer.
Any aspect of the business which is as potentially risky today as in 1976 has a massive problem.
Last edited by birmingham; 26th May 2016 at 12:29.
Now anyone who knows anything at all about the aviation business knows that this unfortunate tragic run that has affected the Puma could have happened in other types. MGB issues are hardly unique to Pumas and the Pumas's maintenance, operations and many components are often supplied by the same companies as AW, Sikorsky, Bell etc.
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I am one of your passengers in the NS, SLF I have heard us referred to, and I'm quite angry about the petitions on Facebook to have the 225 banned. It is IMO an overreaction and based purely on emotion.
I want to see the 225 returned to action asap, the statistics tell me that it is far safer to fly offshore in a 225 than it is to ride my motorcycle when I'm home on leave.
For me the bottom line is if the 2 guys up front are happy to fly the aircraft day in day out then I will get on it.
Just wanted to say!!!
I want to see the 225 returned to action asap, the statistics tell me that it is far safer to fly offshore in a 225 than it is to ride my motorcycle when I'm home on leave.
For me the bottom line is if the 2 guys up front are happy to fly the aircraft day in day out then I will get on it.
Just wanted to say!!!
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I work in technical risk assessment for the offshore industry. When you calculate the risk which the workforce are exposed to, helicopter flying is a significant element. It depends upon the age, layout and complexity of the installation but on a modern platform the transport risk is typically 30 to 40% of the total risk.
Given the workforce have no say in the matter, or influence over it, makes them a hostage to fortune. The oil and gas industry used to boast that helicopter flying was getting safer - and they were right - until recent years, when the accident rate went back up. The oil and gas companies have tried to engage with the workforce to convince them helicopters are safe but been defeated by the accident rate!
Pilots tend to concentrate on the major component failures, but the workforce do not differentiate - pilots flying perfectly serviceable aircraft into the sea has not helped the workforces' perceptions.
When they pay to fly it is fixed wing (virtually always) and typically about 100 times safer than flying in a helicopter. Which sort of sets the scene. Whilst technically helicopters can never be as safe as fixed wing, the helicopter companies and the CAA have been pretty complacent over a non-improving accident rate. CAP 1145 was very much a reflex, certainly not a measured approach.
The longer offshore rotas (3 on, 3 off for instance) will actually change the balance of risks more toward those on the platforms than the flight risks. But it is a comparatively small community and few offshore workers do not know someone who has not been involved in at least a helicopter incident, if not an actual death. I've been in the industry for quite a while and two people I have known have died in offshore helicopters - both onboard the Chinook.
Would you buy a ticket with Malaysia Airways or Egypt Air, if you had the choice of a company with a Western European accident rate for the same money?
Given the workforce have no say in the matter, or influence over it, makes them a hostage to fortune. The oil and gas industry used to boast that helicopter flying was getting safer - and they were right - until recent years, when the accident rate went back up. The oil and gas companies have tried to engage with the workforce to convince them helicopters are safe but been defeated by the accident rate!
Pilots tend to concentrate on the major component failures, but the workforce do not differentiate - pilots flying perfectly serviceable aircraft into the sea has not helped the workforces' perceptions.
When they pay to fly it is fixed wing (virtually always) and typically about 100 times safer than flying in a helicopter. Which sort of sets the scene. Whilst technically helicopters can never be as safe as fixed wing, the helicopter companies and the CAA have been pretty complacent over a non-improving accident rate. CAP 1145 was very much a reflex, certainly not a measured approach.
The longer offshore rotas (3 on, 3 off for instance) will actually change the balance of risks more toward those on the platforms than the flight risks. But it is a comparatively small community and few offshore workers do not know someone who has not been involved in at least a helicopter incident, if not an actual death. I've been in the industry for quite a while and two people I have known have died in offshore helicopters - both onboard the Chinook.
Would you buy a ticket with Malaysia Airways or Egypt Air, if you had the choice of a company with a Western European accident rate for the same money?
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I'm one of the passengers in the NS and have been on and off since 1983, I don't known anybody that has been involved in a helicopter incident.
I am also quite angry by the stuff that appears on Facebook, my nearest and dearest sometimes read stuff on there and I don't want them thinking I'm going to work traveling in a "deathtrap".
I want the 225 to be put back in action asap, for me the risks going to work in a 225 is probably minuscule compared to riding my motorcycle when I'm on leave!!
The bottom line is if the 2 guys up front are happy to fly a 225 day in day out them I'm happy to go with them.
Just saying!
I am also quite angry by the stuff that appears on Facebook, my nearest and dearest sometimes read stuff on there and I don't want them thinking I'm going to work traveling in a "deathtrap".
I want the 225 to be put back in action asap, for me the risks going to work in a 225 is probably minuscule compared to riding my motorcycle when I'm on leave!!
The bottom line is if the 2 guys up front are happy to fly a 225 day in day out them I'm happy to go with them.
Just saying!
