Heli ditch North Sea G-REDL: NOT condolences
Great job by the AAIB - To get the preliminary report out so fast and I certainly feel as a pilot they have given me everything they know.
Chilling reading - Just 13 seconds from calm serene flight - A beautiful day just approaching the coast - To total disaster with no chance of recovery. Absoloutely the stuff my nightmares are made of.
I don't know how similar or not the gearboxes are on different marks of Super Puma ? Can someone elaborate ? I seem to remember a 330J throwing out a gear cog in Asia once but I am not aware of any major gearbox failures on the 332 range since, so I don't doubt it is an incredibly well designed and engineered item. But 2 catastrophic gearbox failures in as many weeks - Unbelievable ??
Chilling reading - Just 13 seconds from calm serene flight - A beautiful day just approaching the coast - To total disaster with no chance of recovery. Absoloutely the stuff my nightmares are made of.
I don't know how similar or not the gearboxes are on different marks of Super Puma ? Can someone elaborate ? I seem to remember a 330J throwing out a gear cog in Asia once but I am not aware of any major gearbox failures on the 332 range since, so I don't doubt it is an incredibly well designed and engineered item. But 2 catastrophic gearbox failures in as many weeks - Unbelievable ??
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Found this on the EC225 thread
"The MGB of the EC 225 is reinforced to accommodate the more powerful engines and the aircraft's increased maximum weight. The casing and gears are made using ultra modern manufacturing materials and processes, which significantly improve the reliability of components"
"The MGB of the EC 225 is reinforced to accommodate the more powerful engines and the aircraft's increased maximum weight. The casing and gears are made using ultra modern manufacturing materials and processes, which significantly improve the reliability of components"
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Apart from the obvious MGB failure,
It is apparent that there was also a rupture in the right hand (No2) engine casing, in the plane of the second stage power turbine. This is currently believed to be a secondary feature. Investigations are continuing in order to understand completely the accident sequence.
Very scary stuff. Its a great pity to see HUMS fail to spot this one coming. The procedure of finding a small metal particle on a chip detector then putting the component onto "close monitoring" is totally standard, but in this case not good enough.
Perhaps it will be a large crack such as was found in the bevel gear of a CHC 332L some years ago, totally un-spotted by HUMS. Since cracks don't release much debris (to be picked up by a chip detector etc) we rely on HUMS, but really HUMS has not evolved much since inception in 1990 or so. We need to get the Neural Network concept being trialled by GE, into service asap.
HUMS was a great invention and step forward, but for the last 20 years the industry has been resting on its HUMS laurels. Not good enough!
HC
Perhaps it will be a large crack such as was found in the bevel gear of a CHC 332L some years ago, totally un-spotted by HUMS. Since cracks don't release much debris (to be picked up by a chip detector etc) we rely on HUMS, but really HUMS has not evolved much since inception in 1990 or so. We need to get the Neural Network concept being trialled by GE, into service asap.
HUMS was a great invention and step forward, but for the last 20 years the industry has been resting on its HUMS laurels. Not good enough!
HC
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Double Bogey;
I agree with young skywalker. I too have been on the end of JFs speculation/inaccuracy/spin/sheer ignorance. We are not public figures and in the event of an accident deserve our privacy. JF, as was discussed in the last accident thread is not reliable as a reporter or witness I hope for your sake you are never the subject of one of his reports.
If JF would like to contact me direct I will back up my statements to him. I am no longer bound by a staff rule about no contact with the press. I doubt he will though, why check your facts when you can call your self an aviation writer?
As for this interim report I flew 2700 hrs on L1s and L2s and always felt confident in the machinery and our training. What happened here is the stuff of nightmares and beyond the comprehension of this pilot. The 332 engendered trust, I will be interested to see if this follows the type of original manafacture error in an MGB cocmponent in a BIH S61n back in 1997.
I agree with young skywalker. I too have been on the end of JFs speculation/inaccuracy/spin/sheer ignorance. We are not public figures and in the event of an accident deserve our privacy. JF, as was discussed in the last accident thread is not reliable as a reporter or witness I hope for your sake you are never the subject of one of his reports.
If JF would like to contact me direct I will back up my statements to him. I am no longer bound by a staff rule about no contact with the press. I doubt he will though, why check your facts when you can call your self an aviation writer?
As for this interim report I flew 2700 hrs on L1s and L2s and always felt confident in the machinery and our training. What happened here is the stuff of nightmares and beyond the comprehension of this pilot. The 332 engendered trust, I will be interested to see if this follows the type of original manafacture error in an MGB cocmponent in a BIH S61n back in 1997.
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Hopefully not going too far OT, Upland Goose posted this back in February, on the McCrae thread Post No 194:
How about this for a scoop!
James Duncan Ferguson was born near Udny Station in Aberdeenshire in July, 1938. He was educated at Robert Gordon's School, Aberdeen and Gordonstoun School.
Service in the Clerical Branch of the Royal Navy followed, between 1957 and 1963, with a number of Fleet Air Arm related postings. Always keenly interested in military and civil aviation matters, he became a specialist writer on the Aberdeen oil-support operation from its ealriest days in the late 1960's. He is Scottish and European aviation correspondent for various British and US publications (Rotr & Wing) as well as a regular contributor to a wide range of specialist magazines. A crew member of the local life-boat and he also covers aviation and rescue matters for both press and radio. He is married to an art teacher, and has lived in Aberdeen since 1963.
Note: This may be a bit out of date - back of the "The Story of Aberdeen Airport 1934 - 1984"
I have met him a few times when I was a co-pilot in the S61N (1977) - a pleasant enough chap - a journalist nevertheless. He used to run a painting and decorating supplies shop in Rosemount Aberdeen - I think.
I rest my case !
UG
James Duncan Ferguson was born near Udny Station in Aberdeenshire in July, 1938. He was educated at Robert Gordon's School, Aberdeen and Gordonstoun School.
Service in the Clerical Branch of the Royal Navy followed, between 1957 and 1963, with a number of Fleet Air Arm related postings. Always keenly interested in military and civil aviation matters, he became a specialist writer on the Aberdeen oil-support operation from its ealriest days in the late 1960's. He is Scottish and European aviation correspondent for various British and US publications (Rotr & Wing) as well as a regular contributor to a wide range of specialist magazines. A crew member of the local life-boat and he also covers aviation and rescue matters for both press and radio. He is married to an art teacher, and has lived in Aberdeen since 1963.
Note: This may be a bit out of date - back of the "The Story of Aberdeen Airport 1934 - 1984"
I have met him a few times when I was a co-pilot in the S61N (1977) - a pleasant enough chap - a journalist nevertheless. He used to run a painting and decorating supplies shop in Rosemount Aberdeen - I think.
I rest my case !
UG
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What they say happened
The AAIB says it was a catastrophic main gearbox failure: http://www.aaib.gov.uk/cms_resources...B%20Report.pdf
Not fully understood yet, but the epicyclic gear was where the problem originated. No way out of that one. The main rotor separated before impact.
What can you say? There was nothing they could do.
Not fully understood yet, but the epicyclic gear was where the problem originated. No way out of that one. The main rotor separated before impact.
What can you say? There was nothing they could do.
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Question?
Please forgive me if I have misinterpreted the report, but if HUMS and normal inspections didn’t pick up a problem with the transmission prior to this disaster how can transmissions of a similar age be deemed safe by simply inspecting them now?
Proves HUMs ain't perfect by far.
I to have been on the end of JF's poor writings. I posted a thread a while ago about the man and it was removed !!
He is nothing more than a spotter and his writings should be ignored or taken with a pinch of salt.
His facts on my case and the pictures used on the front page of the P&J were wrong to the point of slander.
If the bearded git wants to pm me, I will have it out with him and point out the real facts of my case and the a/c in case. I still keep the article in my log book as a laugh at poor journalism.
ITI
He is nothing more than a spotter and his writings should be ignored or taken with a pinch of salt.
His facts on my case and the pictures used on the front page of the P&J were wrong to the point of slander.
If the bearded git wants to pm me, I will have it out with him and point out the real facts of my case and the a/c in case. I still keep the article in my log book as a laugh at poor journalism.
ITI
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Very well done to the AAIB for producing an interim report so soon
.
It is comforting to hear the facts from the experts and not the "Rhubarb of the Speculators" as to the events of this tragic accident.
. It is comforting to hear the facts from the experts and not the "Rhubarb of the Speculators" as to the events of this tragic accident.
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3 O'CLOCK
Sadly, in answer to your question, the only way forward is for the HUMS manufacturer to analyse the data, look for tell tale signs and then set a threshold based on that.
HC
How would you like to see things improve, bearing in the mind the following..
1. The strongest recommendation a HUMS manufacturer can make, upon discovery of a "suspect" vibe signal is close monitoring. And HUMS managers at Line level do not have HUMS OEM levels of experience on the system.
2. Thresholds are set, as you know, usually at a component average signal level + 2 or 3 x Standard Deviation.
3. Not all components are monitored, and one can't simply "switch on a few more sensors".
Don't get wrong, I'm in favour of improvement, but its a huge technological challenge, since the correct thing to do would be to not just cover this one component, but carry out a thorough update of all systems, on all aircraft.. The perfect world we hope to reach is actually do-able, but who is going to pay? As with all technolgy.. Possibility is just a question of money.
I'm not being dismissive, merely being a realist.
Sadly, this is NOT the first time this has happened with the same Aircraft manufacturer.. Only difference was the last time around nobody got killed, a new HUMS threshold was set, and it never made the papers.. I hasten to add, same manufacturer, different aircraft type completely.
FT
Sadly, in answer to your question, the only way forward is for the HUMS manufacturer to analyse the data, look for tell tale signs and then set a threshold based on that.
HC
How would you like to see things improve, bearing in the mind the following..
1. The strongest recommendation a HUMS manufacturer can make, upon discovery of a "suspect" vibe signal is close monitoring. And HUMS managers at Line level do not have HUMS OEM levels of experience on the system.
2. Thresholds are set, as you know, usually at a component average signal level + 2 or 3 x Standard Deviation.
3. Not all components are monitored, and one can't simply "switch on a few more sensors".
Don't get wrong, I'm in favour of improvement, but its a huge technological challenge, since the correct thing to do would be to not just cover this one component, but carry out a thorough update of all systems, on all aircraft.. The perfect world we hope to reach is actually do-able, but who is going to pay? As with all technolgy.. Possibility is just a question of money.
I'm not being dismissive, merely being a realist.
Sadly, this is NOT the first time this has happened with the same Aircraft manufacturer.. Only difference was the last time around nobody got killed, a new HUMS threshold was set, and it never made the papers.. I hasten to add, same manufacturer, different aircraft type completely.
FT
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As P1V1T1 asked a few posts back, are the MGB's different between the various 332 models?
I would guess they are?.....but, are they different enough to cope with the higher power demands of up-rated power plants and gross weights?
I beleive "chip lights" on MGB's are not un common on 332 L, L1's, how common are they on L2's/225's?
I would guess they are?.....but, are they different enough to cope with the higher power demands of up-rated power plants and gross weights?
I beleive "chip lights" on MGB's are not un common on 332 L, L1's, how common are they on L2's/225's?
Perhaps HC can comment on the L2/225 MGB similarities? Is the 225 MGB more or less and L2 MGB with the addition of the glycol injection system?
The only thing I can add of any certainty is that the input modules on the two variants are the same.
VL
The only thing I can add of any certainty is that the input modules on the two variants are the same.
VL
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I am not a pilot, nor do I work offshore, but as my moniker suggests I have more than a passing interest in the events in the North Sea over the past few months.
Having read the initial AAIB report this morning I would just like to say that those of you involved in Offshore Operations out in the North Sea have nothing but my utmost respect.
Stay safe
Having read the initial AAIB report this morning I would just like to say that those of you involved in Offshore Operations out in the North Sea have nothing but my utmost respect.
Stay safe
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Hums
The investigation has so far revealed that the MGB had suffered from a major failure within the epicyclic module. This is supported by HUMS data; however, this is not yet fully understood.
The examination of the MGB is continuing in conjunction with detailed analysis of the HUMS and other recorded information.
So that is where the attention should be focused.
Someone said before that all 3 Aberdeen bases have dedicated HUMS departments, if this is the case, what were these guys doing about it?
If they had reported it to EC and their advice back was 25FH close monitoring and chip det inspections then the buck surely lies with EC. However, if the fault had not been reported to EC, then someone at Bond is clearly in a world of sh*t.
Flytest....
You are incorrect, the strongest reccomendation EC/Hums engineer can make is to ground that particular aircraft and replace the gearbox. It has happened before so why not in this case? I know components are changed all the time in relation to hums data and advice given by the Hums dept and manufacturer so why not in this case? They have mountains of data from other operators all over the world so they have data trends from the whole fleet of their aircraft to analyse. If 1 steps out of line against the others it should be thoroughly investigated.
All gears and bearings within the MGB are monitored by HUMS and it is clear to see by the release of this report that HUMS did pick this up. I suspect this release is to make sure all other AOC around the world checks their HUMS MGB data.
Now with a HUMS alert, it is unlikely that the manufacturer would advise a MGB replacement but it is possible. However, taking that aside, i see the advice given here was to close monitor for 25FH and check the chip detectors? A pretty basic and standard action, well what good is that going to do if their is a crack developing down 1 of the gears?
Why did the HUMS guys/EC not ask for a boroscope inspection of the internal gearing? Why did they not take a SOAP (oil) sample from the GB for further analysis? There is far more they can do than just the basic 25FH close monitor and chip det inspection.
Hums did exactly what it was supposed to do, it appears the advice given by EC/Hums dept was not good enough however.
I read that Norwegian article a few pages back, some scary similarities to that.
16 people are dead here and HUMS picked up on it beforehand. No matter what way you look at it, there was prior warning.
There is clearly nothing wrong with the HUMS system. I suspect the press will have a field day with that above fact if i am being brutally honest.
Very scary stuff. Its a great pity to see HUMS fail to spot this one coming. The procedure of finding a small metal particle on a chip detector then putting the component onto "close monitoring" is totally standard, but in this case not good enough.
Perhaps it will be a large crack such as was found in the bevel gear of a CHC 332L some years ago, totally un-spotted by HUMS. Since cracks don't release much debris (to be picked up by a chip detector etc) we rely on HUMS, but really HUMS has not evolved much since inception in 1990 or so. We need to get the Neural Network concept being trialled by GE, into service asap.
HUMS was a great invention and step forward, but for the last 20 years the industry has been resting on its HUMS laurels. Not good enough!
Perhaps it will be a large crack such as was found in the bevel gear of a CHC 332L some years ago, totally un-spotted by HUMS. Since cracks don't release much debris (to be picked up by a chip detector etc) we rely on HUMS, but really HUMS has not evolved much since inception in 1990 or so. We need to get the Neural Network concept being trialled by GE, into service asap.
HUMS was a great invention and step forward, but for the last 20 years the industry has been resting on its HUMS laurels. Not good enough!
Last edited by WAH; 11th Apr 2009 at 06:16.
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Unfortunately when it comes to HUMs limits the intial values set by the manufacturer can be miles out and only through operational experience will accurate limit values be found.
That doesnt mean testing to destruction but a gradual increase in limits from very low intial values. The idea is that the limits are accurate when components coming back to the shop for failing vibe levels are actually buggered not 90% expensive false alarms.
Only then can you have faith in HUMs.
B412 BHVMS is a good example, Bell had lots of knowledge of vibration levels from the Canadian Griffon HUMs system but as it was military technology they werent allowed to use it for setting civilian values.
SO we all went through a few years, still going a little bit, of pulling stuff off that was pefectly fine.
HUMs is only one tool and its not to be followed with blind faith.
Its all about the interpretation.
I also totally disagree with the above posters comments regarding the HUMs guys and their decisions.
Before we start blame storming maybe we should collect all the facts.
That doesnt mean testing to destruction but a gradual increase in limits from very low intial values. The idea is that the limits are accurate when components coming back to the shop for failing vibe levels are actually buggered not 90% expensive false alarms.
Only then can you have faith in HUMs.
B412 BHVMS is a good example, Bell had lots of knowledge of vibration levels from the Canadian Griffon HUMs system but as it was military technology they werent allowed to use it for setting civilian values.
SO we all went through a few years, still going a little bit, of pulling stuff off that was pefectly fine.
HUMs is only one tool and its not to be followed with blind faith.
Its all about the interpretation.
I also totally disagree with the above posters comments regarding the HUMs guys and their decisions.
Before we start blame storming maybe we should collect all the facts.
Last edited by This aint Jim Beam; 11th Apr 2009 at 05:53. Reason: grammer and comment