Heli ditch North Sea G-REDL: NOT condolences

[gasax]

I do occasionally work offshore and for my day job I'm involved in risk assessment of offshore platforms and the activities on their (and getting to and from them).

The overall accident rate had been showing a gradual reduction in fatal accident rate. I used to be an engineer and actual find the level of that reduction disappointing - given the original accident rates ame from machines designed in the early days of helicopter flight (Wessex etc).

The more recent crashes have changed that rate significantly, but the critical point for pumaboy and others to remember is that the offshore workforce does not get to choose its 'flight provider' or aircraft type. They are captive to whatever arrangements the platform operators have devided. To say this makes them a little sensitive to these events completely understands things.

The vast majority of the workforce would choose not to fly if that were possible add in being told where and when and on what and yes it results in a very nervous workforce.

The overall record of the 332 causes me no issues and the recent MGB failure surprised me as I'm sure it did many others. The results from the AD inspections may show that debris is accumulating in 'other places' and so the issue can be 'fixed' reasonably easily.

On the other hand the S-92 failure very much disappointed me - decent engineering should mean these failures should not be occuring. The element of double speak between a 30 minutes run dry capability and assessing the likelihood as 'extremely unlikely' looks like a classic bean counting decision which should result in the type certificate being pulled.

But if you are worried about the 'damage' being done to the 332 reputation or the aircraft operators' reputations - just try surpressing the information and pretending all is well. The information will get out - the workforce will ensure that and if necesssary then risk dismissal by refusing to fly - remember the Chinooks?

[Geoffersincornwall]

The pax don't get to choose the operator......

The fact that our European offshore helicopter ops must all comply with the rigours of JAROPS 3 should be a comfort. These regs put such ops on a par with the airlines. In the US the offshore ops are categorised as 'charter flights' and work to a much lower set of standards (FAR 135) - nothing like the US airline standards. I feel for the guys that have to travel with the operators over there. I know there are some good companies in the US and they are doing what they see as their best but poor regulation equals poor oversight and therein lies the rub!

G

[helimutt]

gasax, I agree and would just say, there is a need for truthful, open information sharing in this industry. If everyone knows the 'facts' and not spurious ridiculous gossip at every caution light. Tell someone the truth, and with common sense, can make their own decision if flying offshore is for them or not.

[NorthSeaTiger]

New fears over Helicopter

A super puma helicopter like the one involved in this months north sea tradgedy has been taken out of service after making a precautianary landing.

In the latest incident the aircraft had just taken off when the crew were alerted to an oil related issue .

Any more info ?

NST

[Camper Van Basten]

I'm guessing it's a tiny bit of residual oil which came out from under a trim panel. Hardly surprising considering the major disruption in that area while carrying out the mods, and the associated multiple drainings / refilling of the MGB.

Like I say, only guessing.

[gasax]

Geoffers has a point but it certainly is not a unique selling point. The 'rigours' of JAR OPS3 have not stopped the last 2 CFIT(W). But initiative such as that from DB may - if they gain industry acceptance.

The 'rigours' of JAR OPS3 still give us fatal accident rates for commerical helicopters which depending on how you slice the data are from 10 to about 100 times more dangerous than fixed wing operations - by sector or hour.

It is not all gloom - the industry is beginning to think in risk management terms and spokespeople such as Nick Lappos have presented the 'obvious' way forward for rotary flight but there is a long way to go from where we are today.

As far as risk perception is concerned (offshore workers smoking, helicopter plots flying) - never expect the decisions to be completely rational!

[databoy]

Dear ppruners: I've looked back through the thread and been to Eurocopter's website, can anyone (in the know, not wikipedia-based research please !) tell me how many:

332Ls ?
332L2s ?
& EC225s ?

Are actually currently in service in offshore configuration around the world ?

Many thanks.

[skydriller]

'Workforce Helicopter Briefing'

I have just recieved a 'Workforce Helicopter Briefing' via my company's HSE Director, which I believe has been sent out to all Offshore personnel, but just in case it doesnt reach everyone, I know several offshore guys have been keeping an eye on this thread, so I will post it below.

I would also be interested in any comments you guys flying us offshore may like to make about it.

Regards, SD..

Workforce Helicopter Briefing - Q&A

This briefing is designed to update workers on the recent issues raised surrounding offshore helicopter travel, including the temporary suspension of some flights.

Which flights were suspended?
The two types of aircraft affected were the AS332 L2 and the EC225, both belonging to the Super Puma family and manufactured by Eurocopter. The Super Puma family of helicopters is used by more than 100 operators in 50 countries. 640 aircraft of the Super Puma family are currently in service around the globe, in both the civil and military sectors.

Why were the flights suspended?
The flights were suspended following the publication of a second Air Accident Investigation Branch initial report, and subsequent Alert Service Bulletins from Eurocopter and an Air worthiness Directive from EASA (European Aviation Safety Agency)

Who made the decision to suspend the flights?
An EASA Airworthiness Directive (AD) required an immediate internal inspection of the gearbox and this work was done in conjunction with a modification which is discussed later. The decision to carry out this work concurrently was made voluntarily by the UK helicopter operators to eliminate one unnecessary maintenance intervention, and that was supported by the oil and gas industry.

Who are the authorities involved?
There are a number of authorities involved in the recent investigation and subsequent recommendations and directives. These are:
 AAIB (Air Accident Investigation Branch) – The body responsible for investigating the causes of aviation accidents. The AAIB issue reports which contain recommendations, based on their findings, which are designed to correct or improve safety issues in light of the incident they are investigating.

 EASA (European Aviation Safety Agency) – The aviation regulator within Europe. EASA considers recommendations from the AAIB reports and, in conjunction with the manufacturer of the helicopter, may develop an Airworthiness Directives (AD) to mandate the maintenance requirement. EASA regulates compliance with these AD’s.

 CAA (Civil Aviation Authority) – The UK aviation regulator which enforces EASA directives within the UK.

 Eurocopter – As the manufacturer of the Super Puma aircraft, Eurocopter issues Alert Service Bulletins (ASB) based on the recommendations from AAIB. these ASB’s are passed on to the helicopter operators and prescribe the technical instructions. EASA then mandates that ASB with an AD
Please note that any AD issued by EASA is European specific but is normally adopted by all other aviation regulators, globally. An ASB issued by Eurocopter applies to all helicopters of that type across the globe.


What is the timeline for the various reports and requirements issued by these bodies?

1st April 2009 The AS332L2, G-REDL, crashes off the coast of Peterhead. The AAIB begin their investigation

10th April 2009 AAIB issue their Initial Report. The report contains 3 recommendations:

1. Eurocopter issue an Alert Service Bulletin to require all operators of AS332L2 helicopters to implement a regime of additional inspections and enhanced monitoring to ensure the continued airworthiness of the main rotor gearbox epicyclic module.
2. European Aviation Safety Agency (EASA) evaluate the efficacy of the Eurocopter programme of additional inspections and enhanced monitoring and, when satisfied, make the Eurocopter Alert Service Bulletin mandatory by issuing an Airworthiness Directive with immediate effect.
3. Eurocopter improve the gearbox monitoring and warning systems on the AS332L2 helicopter so as to identify degradation and provide adequate alerts. (longer term)

10th April 2009 Simultaneous to the AAIB Report being issued, Eurocopter issued their ASB and EASA their AD as per the AAIB recommendations

17th April 2009 AAIB issue their second Initial Report. The report contains one recommendation:

1. Eurocopter, along with EASA, to develop and implement an inspection of the internal components of the main rotor gearbox epicyclic module for all AS332L2 and EC225LP helicopters as a matter of urgency. This inspection is in addition to that specified in the original EASA AD, and should be made mandatory with immediate effect by an additional EASA AD.

17th April 2009 EASA issue an AD as per the recommendation in the second AAIB report for a one-time inspection of the epicyclic module (by removal and inspection) in accordance with existing Eurocopter technical instructions.

18th April 2009 Eurocopter issue an ASB detailing a modification to the gearbox as per the 3rd recommendation of the first AAIB report. As yet, EASA has still to mandate this work but, importantly, the helicopter operators will embody the modification before each helicopter returns to service.

What exactly will the inspections and modifications entail?
These recommendations resulted in Alert Service Bulletins being issued by Eurocopter which implemented the following precautionary measures:

1) The inspection frequency of the magnetic plug of the epicyclic stage be increased from every 25 flight hours to every 10 flight hours on the AS332L2. The EC225 magnetic plug is connected directly to a warning caption in the cockpit.

2) A one time inspection to be carried out on the epicyclic module which required physically opening the gearbox to check for loose particles. (Applicable to both the AS332L2 and the EC225)

3) The magnetic elements installed on the chip collector and the flanged edge from the chip collector to be removed in order to improve the flow of particles towards the magnetic plug detection devices which are located in the gearbox sump and epicyclic module (Applicable to both the AS332L2 and the EC225)

Where is the epicyclic module? (Schematic Attached)
The gearboxes within the AS332L2 and EC225 Super Puma’s are made up of two modules – the main module and the epicyclic module. The epicyclic module is equipped with 25 magnets and 1 magnetic chip detector; although a total of 3 detectors monitor the gearbox. The magnetic chip detector (like the magnets) is designed to catch any metal particles within the gearbox. When a metal particle is caught by the detector within the epicyclic module, an alert will trigger within the HUMS and, in the case of the EC225, an automatic warning in the cockpit will also be activated.

When will these inspections/modifications have to be completed?
The new inspection frequency was put into effect immediately on 11th April, so any of the affected aircraft flying from that date will have complied with these measures.
Although the regulator allowed an extended period over which to complete the modification, helicopter operators and the oil industry felt it was important to combine the one time inspection and modification steps and carry them both out before any aircraft flew again. This is why the use of these aircraft has been temporarily suspended and they are being returned to use progressively as the work is completed.

What is thought to have caused the 1st April accident?
Whilst it is apparent that a gearbox failure occurred during the accident, and a metal chip had been detected a week previously on the aircraft, it is not yet known whether these two factors are linked or what the exact cause of the accident was. The AAIB has said that the way in which the gearbox failed may mask the initial failure mechanism and make it more difficult to identify the actual cause.

Are gearbox failures common in Super Puma’s?
The Super Puma family has more than 3.7 million flight hours flown around the world over the last three decades, and this is the first gearbox failure which has been experienced. The L2 model alone has been in use for 15 years with just under half a million flight hours flown.

Did the recent Canadian accident involve the same issue as the 1st April accident?
The investigation into the Canadian Sikorsky S92 accident in February also centres on a potential gearbox failure. Whilst the investigation is continuing, the cause in this case appears to have been a loss of oil from the gearbox, possibly linked to the failure of titanium studs on an oil filter bowl. These titanium studs have now been replaced by steel studs on all aircraft flying within the UK, in accordance with an ASB issued by Sikorsky which is the helicopter manufacturer in this case. The two accidents therefore have different causation and the two aircraft concerned were different types from different manufacturers.

[WAH]

As far as im aware from reading through the ASB is that the actual epicyclic module is NOT inspected.

The epicyclic module is removed as a 'sealed' unit on the L2's and the bottom portion of the gearbox is where the magnets are housed. All the work is being done here on removal of the magnets and modification to the oil collector plate to allow oil to fall down back into the sump to be picked up by the magnetic plug.

It's a strange move as the AAIB have stated that there was a failure within the epicyclic module but yet this ASB does not focus its attention around that? (i.e a direct detailed inspection of all the gears and bearings)

To put into summary, if there is a flaw with the upper planet gears/bearings, upper sun/ring gear, then they would not be picked up by this inspection.

Something in the epicyclic part failed in G-REDL and this inspection as far as i am aware is doing nothing to stop it from happening again. The removal of the magnets will allow more metal particles to be picked up by the plug BUT what if its a crack in 1 of the gears or a bearing that gives off little or no material?

Can any other engineers or pilots in the know comment on this inspection and confirm or deny if my understanding of the procedure is correct?

WAH

[widgeon]

OWNER 332C 332L 332L1 332L2 EC225
BOND 0 0 0 7 3
BRIST 0 24 1 1 9
CHCI 1 15 4 16 6
LLOY 0 3 4 0 0
NORS 0 0 1 2 0


Data boy as close as I can see this is the distribution of offshore operators.

There may be a few I have missed.

[WaveWarrior]

Yesterday I was looking at the epicyclic module and oil collector plate of an EC225 gearbox which had been removed from the aircraft for inspection. My understanding is that a detailed physical inspection of the whole module is required as well as the removal of the magnets on the collector plate.

[databoy]

Widgeon, Many thanks for the numbers.

[js0987]

Does the "physical inspection" require magnafluxing or xraying or is it just a visual inspection?

[you want what??]

widgeon,

Bond, according to G-INFO database, was 8 and 3 now 7 L2's and 2 EC225's just for the sake of accuracy (also operate L2 for JIGSAW)

As for the inspection of the epicyclic, when ever we take something apart, no matter what it is, we usually inspect everything with a fairly detailed visual inspection anyway, weather mandated by the maintenace procedure or not. its just good engineering practice.

[HeliComparator]

just for the sake of accuracy (also operate L2 G-JSAR (JIGSAW))

Just for the sake of accuracy, G-JSAR was operated by Bristow until it ditched off Den Helder in 2006 and was eventually declared an insurance write-off.

HC

[drop lead]

Inspection findings

By now I would guess most of the L2's and 225's have had the epicyclic modules inspected?
Does anyone know if any additional problems have been found?

[L2driver]

Inspection findings

Nothing is found so far , and that is a bit scary

[JimL]

L2driver,

That is exactly what you should have expected; to think otherwise would be to anticipate that there is a fatal flaw in this type of gearbox. Clearly that is not true otherwise the record of reliability in the life of the L2 and 225 gearboxes would look somewhat different.

Those who have seen the debris trays and looked at the (now removed) magnets, have remarked on the lack of deposits; at the most, on a near term gearbox, a mere smear of substance (not even enough to excite a fuzz-burner).

As was said previously, we will have to rely upon what can be deduced from the intact data collected in the VHM/HUMS system.

Jim

[SASless]

JimL,

There is at least one fatal flaw!

Whether it is design, manufacturing, engineering, or material failure is yet to be decided.

[Brian Abraham]

Jim, do you know if they have a "complete" gear box, or might the offending piece have been ejected in the break up and lying some where on the sea bed?