North Sea heli ditching: Oct 2012
Terminus - they not looking at the shaft material anymore but of course that was the first idea!
What amazes me is the relaxed attitude to spec changes with little idea of the testing regime. You know if we (couple pilots from here say) set up a passenger transport biz with some EC225's and decided we would change drive shafts for our own design/spec or re-mapped the motor - whatever - then lost a couple due to failure we would be destroyed in all ways possible and rightly so.
Here the CEO makes a field trip to spin the PR and charm and puts out completely misleading and meaningless stats (like 250k hours). Lets see what the root of this issue is and how tested it was. I suspect the truth will be alarming.
What amazes me is the relaxed attitude to spec changes with little idea of the testing regime. You know if we (couple pilots from here say) set up a passenger transport biz with some EC225's and decided we would change drive shafts for our own design/spec or re-mapped the motor - whatever - then lost a couple due to failure we would be destroyed in all ways possible and rightly so.
Here the CEO makes a field trip to spin the PR and charm and puts out completely misleading and meaningless stats (like 250k hours). Lets see what the root of this issue is and how tested it was. I suspect the truth will be alarming.
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Are you sure everything is misleading and just PR? If the CEO didn't go himself you probably would have demanded that he does face the music as EC CEO directly but now that he did it is a farce!? 2 post 2009 shafts cracked inflight and there were 2 ditchings! The material/processes were changed in 2009 but then also there were performance changes on the engines it seems in 2010! Harmonics with so many rotating components is a huge problem(again i am not in this game but just take the FLM on the 350's excl b3 ensuring that no time is spent between 285-315 rpm I think due possible harmonics)! Did they test any 2 of the possibilities so far?-I do not know but neither do you so dont just assume because it is EC they did not!
I am amazed by some of the unknowns in aviation everyday despite the enormous costs and involvement of certification and safety institutions and regulatory institutions! If you were involved on the 350 you would have had a field day with the B3e situation, yet the factory machine has flown a lot of hours without any showing of any possible failure whilst some delivered machines have problems at 20hrs!
Just amazes me as said before that we are refurring to older machines as reliable and should be preferred, but those were the days we complained about engine performance and power! So my question remains: Did we reach a point were engine technology has superseded airframe structure and dynamic ability/technology because we have 3 new generation twin heavy aircraft with excellent performance yet they all 3 have either MGB/structure issues or both and we have a ultra reliable single with TR issues(and dont go off at EC cause we have all been threw the 407 issues a while back so definately not limited to 1 manufacturer).
I am amazed by some of the unknowns in aviation everyday despite the enormous costs and involvement of certification and safety institutions and regulatory institutions! If you were involved on the 350 you would have had a field day with the B3e situation, yet the factory machine has flown a lot of hours without any showing of any possible failure whilst some delivered machines have problems at 20hrs!
Just amazes me as said before that we are refurring to older machines as reliable and should be preferred, but those were the days we complained about engine performance and power! So my question remains: Did we reach a point were engine technology has superseded airframe structure and dynamic ability/technology because we have 3 new generation twin heavy aircraft with excellent performance yet they all 3 have either MGB/structure issues or both and we have a ultra reliable single with TR issues(and dont go off at EC cause we have all been threw the 407 issues a while back so definately not limited to 1 manufacturer).
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The 225 out of Aberdeen at MTOW with no wind and just above average temperatures on a clear area departure has to be treated with respect for fear of much bonging. Watch all three companies as they sink back towards the tarmac on rotation. It feels like an aircraft that is being pushed hard.
The majority of ABZ departures are at MTOW, could this be part of the reason we have seen the failures first on the North Sea?
The majority of ABZ departures are at MTOW, could this be part of the reason we have seen the failures first on the North Sea?
I think the power to weight ratio of the 225 and 332L are about the same at max wt, of course the difference is that the 225 has a vastly greater disposable load so spends more time lighter.
Despite what you say, unless carrying 19 one is rarely within say 100kg of MTOM and often well below it. I think percentage-wise the 225 flies lighter than the 332L on average (ie % of MTOM). However as you say, it feels heavy at MTOM.
Some people make life difficult by opting for Vtoss = 80. Personally I never go for that because it is a struggle to maintain the prescribed accelerative attitude whilst climbing slightly, within the Tq limit, when approaching 70kts. Better to go for indicated Vtoss + 5 to 10 or so, which never seems to be more than 60.
Despite what you say, unless carrying 19 one is rarely within say 100kg of MTOM and often well below it. I think percentage-wise the 225 flies lighter than the 332L on average (ie % of MTOM). However as you say, it feels heavy at MTOM.
Some people make life difficult by opting for Vtoss = 80. Personally I never go for that because it is a struggle to maintain the prescribed accelerative attitude whilst climbing slightly, within the Tq limit, when approaching 70kts. Better to go for indicated Vtoss + 5 to 10 or so, which never seems to be more than 60.
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Victor Papa
There were some Fadec changes and EC is currently examining the effect of Version 12 Fadec software which was released in response to the 14 Hz vibration to slightly lower the Nr.
The material/processes were changed in 2009 but then also there were performance changes on the engines it seems in 2010!
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Tks terminus mos, that is very interesting the possible effect of even a small rotor rpm change?
rotor-rooter, the B3e is limited to 100kts VNE due to the Paulstra bearings failing on the TR blade. They are also subject to a 3hr inspection of the 4 laminated(Paulstra) bearings. I believe ECF is starting in Dec to retrofit the load compensator back onto the tail servo and remove the additional flyweights of the TR blade chinese weights. Before we have a EC attack again the factory machine flying all possible conditions apparently has shown no signs of this. Secondly, the load compensator was replaced by the fly weights in order to assist the pilot aerodynamically with RH pedal incase of hydraulic failure I believe whereas the load compensator does it hydraulically trapping fluid over itself and the accumualtor IF YOU LEAVE THE "ACCU/HYD TEST" SWITCH ALONE ON THE CONSOLE. So it seems the purpose was to eliminate human error due using the "test switch" on the console instead of HYD ON/OFF on the collective incase of a hydraulic failure. I thought it was brilliant when I first saw it and received training on it-in hindsight it is not!
Following both incidences on these 2 well known aircraft with interest as all can learn a enormous amount I believe.
rotor-rooter, the B3e is limited to 100kts VNE due to the Paulstra bearings failing on the TR blade. They are also subject to a 3hr inspection of the 4 laminated(Paulstra) bearings. I believe ECF is starting in Dec to retrofit the load compensator back onto the tail servo and remove the additional flyweights of the TR blade chinese weights. Before we have a EC attack again the factory machine flying all possible conditions apparently has shown no signs of this. Secondly, the load compensator was replaced by the fly weights in order to assist the pilot aerodynamically with RH pedal incase of hydraulic failure I believe whereas the load compensator does it hydraulically trapping fluid over itself and the accumualtor IF YOU LEAVE THE "ACCU/HYD TEST" SWITCH ALONE ON THE CONSOLE. So it seems the purpose was to eliminate human error due using the "test switch" on the console instead of HYD ON/OFF on the collective incase of a hydraulic failure. I thought it was brilliant when I first saw it and received training on it-in hindsight it is not!
Following both incidences on these 2 well known aircraft with interest as all can learn a enormous amount I believe.
Last edited by victor papa; 18th Nov 2012 at 06:15.
Victor P - of course I don't think everything out of EC is PR but it most certainly is when you roll out a CEO who then quoted meaningless marketing type numbers (which the 250k hours stat is). No doubt he continued with lines such as how committed everyone at EC is to safety, how they have full commitment and confidence that all problems will be resolved.. Etc etc blah blah.
It's a CEO what else can he say? It is nothing more than grandstanding so someone can then make a press release saying how serious EC takes this because they sent a lot of men in suits. Kind of patronising really wouldn't you say?
Rather than trot out the 250k hours why not say how many hours they tested these new nitrided shafts or new engine maps or how many hours a fleet leader has done with all the latest updates?
The point which is easy to miss is that the passengers dont care about helicopters or the latest map that someone down loads etc to them an EC225 is like a bus that takes them to work.
My point is that all this fiddling with specs is dangerous because testing will be in simulation and static rigs in the main and sadly it's not good enough. The limitations with new types stem in my belief in manufacturers trying to evolve old designs to increase profit margins - which is fine until it isn't. At some point you can't keep putting patches on things.
The question I'd like to know the answer to is what spec is a 2012 EC225 and in that latest format how many flying hours had the fleet leader prior to the May accident.
It's a CEO what else can he say? It is nothing more than grandstanding so someone can then make a press release saying how serious EC takes this because they sent a lot of men in suits. Kind of patronising really wouldn't you say?
Rather than trot out the 250k hours why not say how many hours they tested these new nitrided shafts or new engine maps or how many hours a fleet leader has done with all the latest updates?
The point which is easy to miss is that the passengers dont care about helicopters or the latest map that someone down loads etc to them an EC225 is like a bus that takes them to work.
My point is that all this fiddling with specs is dangerous because testing will be in simulation and static rigs in the main and sadly it's not good enough. The limitations with new types stem in my belief in manufacturers trying to evolve old designs to increase profit margins - which is fine until it isn't. At some point you can't keep putting patches on things.
The question I'd like to know the answer to is what spec is a 2012 EC225 and in that latest format how many flying hours had the fleet leader prior to the May accident.
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Pittsextra, what does it really matter how many hours the fleet leader has got or the fleet for that matter? Think a figure of 10 000hrs was mentioned for the fleet leader? Should the question you want a answer to not be how many gearboxes has been threw their first or second overhaul instead of airframe hours? What is the TBO on the 225 MGB? Normally it is in the range of 3000hrs and if that is the case the fleet leader at 10 000hrs will be on her 4th gearbox? Is there even a relation between MGB hours and airframe hours as they get overhauled and shipped in most cases to different airframes? How many hours does the leading MGB have should be the question? Where there any signs of failure or possible failure prematurely during the overhauls or repairs if applicable? Where these MGB's brand new or have they been repaired or overhauled? Is their a similiarity in the MGB hours on the 2 that failed even if not between the airframes?
Just asking as a 10 000hr machine can have a incicent on a brand new MGB thus the airframe hours not the benchmark but the MGB hours?
Just asking as a 10 000hr machine can have a incicent on a brand new MGB thus the airframe hours not the benchmark but the MGB hours?
V.P. It's might not even be the MGB Hours. In the Maint Manual (MM) is the Component Overhaul Table (COT) which shows the O/H life of each component (which is subject to a life) of the MGB, plus the rest of the aircraft. The main shaft might well have a longer life than the O/H life of the MGB. On some helicopters this is the case but without having the 225 MM to hand I don't know.
So until the life of the main shaft is known the airframe hrs and MGB hrs mean very little.
So until the life of the main shaft is known the airframe hrs and MGB hrs mean very little.
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Agree with you fully and that was the point I tried to make. On the smaller EC's we have Time Between Overhaul, Operating Time Limit and then Service Life Limit which when reached the component gets replaced regardless(typical example is the starflex). The TBO of a MGB can be 3000hr but the first SLL can be as high as 9000hrs so unless there is a premature failure the MGB will get overhauled twice before the first replacement on the 3rd OH. If most of the critical components have a SLL of say 9000hrs it could mean that a 10000hr MGB has newer components than a 2000hr MGB which has not even reached OH. I also do not have the specific limits for the 225 so do not know what the relationship is which is why I asked Pittsextra what is the real meaning of the airframe hours or fleet hours. Of real interest will be where these MGB's and their components were in their cycles and indeed whether both MGB's had exactly the same part numbers of different components fitted and/or mod status vs other MGB's in the cycle that have not failed?
There are much more to investigate than the shafts that cracked due to the why did they crack if one takes into consideration all the possibilities of hrs, component hrs, component mod status etc
There are much more to investigate than the shafts that cracked due to the why did they crack if one takes into consideration all the possibilities of hrs, component hrs, component mod status etc
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PITTSEXTRA - your comments re the EC CEO are way off mark as is your assumption that EC are NOT committed to safety. The fact that the CEO turned up should demonstrate to you just how committed he is to chasing this complex problem down, and it is complex. If it was not it would have been solved by now.
Crikey Double Bogey when I wrote in my last post :-
You just proved my point.....
I don't care for EC one way or the other, I have no axe to grind but this is what we find.
Helicopter G-REDW ditches 10th May. On the 18th May you get EASA AD 2012-0087E with a suggestion of a manufacturing defect. You then get updates and revised EASA notices such that on 28th June you get AD 2012-0115E which says (to be brief) that crack initiation could occur at lower MGB torque levels than appreciated..... then obviously we get the accident of G-CHCN and suddenly all bets are off regarding a certain batch of shafts and now its looking like the EC225 is out of action until at least Feb 2013 - why because they don't seem to fully understand the issues.
Now forgive me but how does that summary suggest EC have even a good grasp of what they have?
Even 2 of the 3 operators, prior to the October ditching, were running a tighter HUMS download schedule that EC recommended because they were clearly unconfident in the situation at that time. The latest bitter pill is the effective grounding of the craft by the CAA, who have a different take than EASA..
The CEO is lucky to be in his post although maybe after Bristow's move to Sikorsky perhaps that could change and also depending on legal after shocks because there is no doubt the claims will come after this shambles.
Victor - Why do I bang on about a in flight testing and a fleet leader ? because as you can see running things up on a test rig doesn't gain a true picture of the components in normal operation. If it did these drive shafts wouldn't have broken and you wouldn't have this because it would have been sorted from the beginning:-
It is cynical but when a CEO starts quoting data like 250K hours its just meaningless, especially since we seem to have new drives shafts and a version 12 (twelve!) Fadec software... I can read this off EC website:-
Oh really 39300 hours? and how many in the spec of the ones that ditched?
of course I don't think everything out of EC is PR but it most certainly is when you roll out a CEO who then quoted meaningless marketing type numbers (which the 250k hours stat is). No doubt he continued with lines such as how committed everyone at EC is to safety, how they have full commitment and confidence that all problems will be resolved.. Etc etc blah blah.
I don't care for EC one way or the other, I have no axe to grind but this is what we find.
Helicopter G-REDW ditches 10th May. On the 18th May you get EASA AD 2012-0087E with a suggestion of a manufacturing defect. You then get updates and revised EASA notices such that on 28th June you get AD 2012-0115E which says (to be brief) that crack initiation could occur at lower MGB torque levels than appreciated..... then obviously we get the accident of G-CHCN and suddenly all bets are off regarding a certain batch of shafts and now its looking like the EC225 is out of action until at least Feb 2013 - why because they don't seem to fully understand the issues.
Now forgive me but how does that summary suggest EC have even a good grasp of what they have?
Even 2 of the 3 operators, prior to the October ditching, were running a tighter HUMS download schedule that EC recommended because they were clearly unconfident in the situation at that time. The latest bitter pill is the effective grounding of the craft by the CAA, who have a different take than EASA..
The CEO is lucky to be in his post although maybe after Bristow's move to Sikorsky perhaps that could change and also depending on legal after shocks because there is no doubt the claims will come after this shambles.
Victor - Why do I bang on about a in flight testing and a fleet leader ? because as you can see running things up on a test rig doesn't gain a true picture of the components in normal operation. If it did these drive shafts wouldn't have broken and you wouldn't have this because it would have been sorted from the beginning:-
There were some Fadec changes and EC is currently examining the effect of Version 12 Fadec software which was released in response to the 14 Hz vibration to slightly lower the Nr.
The EC225 has evolved from the vast experience accumulated by some 100 Super Puma operators; some 900 helicopters have been ordered in 52 countries. The in-service Super Puma fleet has logged more than 4,4-million hours and the fleet leader has flown 39,300 hours.
In the seventies Lycoming had a problem with the T53 turbine nozzle guide vane unit. The original manufacturer had gone out of business so they had someone else make them from the drawings, as I understand it these new ones used to crack and it took some time to sort out.
My point is that why did ECF change the welding technique after so many hours without failure of the shaft. Also, the shaft is said to have failed in the area of the weld, normally any weld is said to be stronger than the original, which indicates, to me, a failure other than the weld failing.
My point is that why did ECF change the welding technique after so many hours without failure of the shaft. Also, the shaft is said to have failed in the area of the weld, normally any weld is said to be stronger than the original, which indicates, to me, a failure other than the weld failing.
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MGB cut away
Might be a little late for this but here is a photgraph of a sectioned AS332 MGB on a stand - training aid. You can see one of the pumps at the bottom also sectioned.
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Thank you to Biggles and Colibri for clearing up my misunderstanding.
Also, the last two pages have a lot of good meat. Very glad to have kept following this thread, a great deal of useful analysis and food for thought.
The emergency lube system foibles are an eye opener.
Also, the last two pages have a lot of good meat. Very glad to have kept following this thread, a great deal of useful analysis and food for thought.
The emergency lube system foibles are an eye opener.
Last edited by Lonewolf_50; 19th Nov 2012 at 13:12.
and a version 12 (twelve!) Fadec software...
So 7, 9, 11, 12 which doesn't sound so bad!
There have been some good improvements, eg with v7 &9 a double N1 sensor failure would give a FADEC freeze, after v9 a software strategy was developed to deal with that (just as well as we have had a couple of double N1 sensor failures just resulting in a GOV since!)
This is meant as humour:
One thing I find amusing is that when I made the mistake of referring to a 225 as a Puma while on course I was informed, in no uncertain terms, that the 225 was NOT a Puma! Incredible new technology ect. ect.
Now when some "good" stats about hours safely flown are needed the 225 is suddenly a Puma.
I hope we can all go back to work soon!
Time for that second cup of morning coffee.
One thing I find amusing is that when I made the mistake of referring to a 225 as a Puma while on course I was informed, in no uncertain terms, that the 225 was NOT a Puma! Incredible new technology ect. ect.
Now when some "good" stats about hours safely flown are needed the 225 is suddenly a Puma.
I hope we can all go back to work soon!
Time for that second cup of morning coffee.