North Sea Helicopter ditching 10th May 2012 [Archive]

HeliComparator

10th May 2012, 16:36

Anyone brave enough to explain emlube?

The Emergency Lubrication system allows 30 minutes at Vy (80 kts) so whilst that is a "good thing" as in general it will allow one to land somewhere solid, that cannot be guaranteed if the heli is outside 40 miles (still air) from a landing opportunity. Since the aircraft came down allegedly 25 miles from EGPD it was perhaps in that slightly awkward zone inside of 80 miles with few landing opportunities. Not sure what the wind direction was but looks NE so hard to turn back out to sea and into wind to reach an installation further out.

At least the 30 mins allows SAR to be launched and reduces time in the water / dinghies.

Of course it is possible for the emergency lube system to fail to activate (or at least, to give indications of failure) in which case the drill is land immediately. At this stage only a select few know if this happened, and I am not one of them!

Are the Bond ec225 not equipped with glycol 30 min. lubrication?

Yes, as are all EC225s - it is part of the certification requirement, not an optional extra.

HC

louisnewmark

10th May 2012, 17:51

30 min 'run dry' time doesn't mean that you can run for thirty minutes without MRGB oil before landing; it means (IMHO) that you should consider that you have 30 mins max to effect a landing in the safest place possible, and the closer you are to the 30 mins point the closer you are to a catastrophic failure. The captain's primary responsibility isn't to maximise profitability for the shareholders, or even to minimise the cost of an aircraft recovery; it is to maximise and ensure, as far as is possible, the safety of the passengers. On the basis of the limited information available thus far, the captain here achieved that admirably. Kudos, my friend; I'm glad I've never been faced with that situation.

DauphinDude

10th May 2012, 18:16

So what is it that Bond does wrong? Is this simply the third "freak accident"?

Sir Korsky

10th May 2012, 18:17

Very true Louis, if the aircraft has screwed you, then screw it!::) Seems like the perfect outcome here.

mtoroshanga

10th May 2012, 18:28

I would suggest that you cease your inane uneducate waffle about this incidente
if you recall the S92 that speared in off Newfoundland a couple of years ago had an MEL statment that the gearbox could run for 30 mins without oil and this led to the crews deciion to make for land
The crew involved in this event ditched, good for them.

pitpilot

10th May 2012, 18:32

3rd accident by Bond in as many years true, but glad they all got out, reports are out or imminently out on the last 2 the Etap ditching makes for interesting reading and is used in CRM courses as a talking point.

HeliComparator

10th May 2012, 18:43

mtoroshanga

Please try not to post totally inaccurate information when the truth is in the public domain - it just causes confusion

First of all, the MEL only applies when one is on the ground.

Secondly, neither the MEL nor the emergency procedures in the S92 flight manual says that the S92 can run for 30 minutes without oil. The only thing that said that was sales material.

Louis. I agree to a certain extent, but depending on sea conditions and the proximity of a safe landing site, it might or might not be appropriate to continue for the full 30 minutes. Clearly in this case the crew made the correct decisions because everyone was OK.

louisnewmark

10th May 2012, 18:52

depending on sea conditions and the proximity of a safe landing site, it
might or might not be appropriate to continue for the full 30 minutes.

Yep, absolutely agreed - that's pretty much what I meant by 'the safest place possible'.

Louis

ARRAKIS

10th May 2012, 19:03

30 minutes is the requirement. Given the quantity of glycol in the EC225 ELS, how much MGB runing time would it give?

Arrakis

biddedout

10th May 2012, 19:03

Not even showing as an item on the BBC website now. Obviously no celebrities on board and no one wiling to say they were screaming all the way as the jet plunged to the bottom of the sea.:rolleyes:.

Ray Stawynch

10th May 2012, 19:21

Thank God that all involved walked away from this unfortunate incident. And absolutely Sterling effort from the lads on Rescue Bond One, RAF Boulmer and the RNLI.

ASWFlyer

10th May 2012, 19:33

Well done to the chaps up front! If i'd been onboard i'd certainly be buying the crew a pint or two tonight.

They certainly earnt their money today. :D

The traditional saying of 'any landing you can walk away from is a good landing' doesn't really apply here... but perhaps 'any landing you can walk or swim away from is a good landing' should be introduced...? :ok:

hypnosteve

10th May 2012, 19:41

I think the question is, 'Is a light, a ditching decision?'

chopabeefer

10th May 2012, 19:45

Depends on the light.

Wizzard

10th May 2012, 20:14

I think the question is, 'Is a light, a ditching decision?'

I think you might find in this case it might be a light, a noise and a smell!

Well done guys, proud of you

hihover

10th May 2012, 20:17

You may wish to take a few seconds for thought before you post.

There would be two professional EC225 pilots at the front end who do this stuff day in day out. Do you think that they just saw a light and ditched an aircraft with 14 pax into the North Sea?

Tam

HeliComparator

10th May 2012, 20:25

I think the question is, 'Is a light, a ditching decision?'

Captions (not lights!):
MP - main pump pressure
S/B.P - standby pump pressure

Lights:
Red MGB.P with flashing red WARN - main gearbox pressure

Gauge:
Transmission oil pressure in the red

So with those 4 things, each with a seperate sensor, all triggered, something is up!

Now we have to press the emerg lube buton and have 30 minutes at Vy

If 30 mins is approaching, or if a 5th light MGB EMLUBE (with yet another pair of sensors) illuminates, only then do you ditch.

By that time, there can be no doubt that something is up, so your comment about "a light" shows a certain lack of knowledge of the systems involved.

HC

747 jock

10th May 2012, 20:26

The 2 people at the front have to make a very quick decision, and their only concern is for the safety of themselves and their passengers.
In todays incident, their decision resulted in what will probably be a written off helicopter (which will be paid for by an insurance company), and no harm to the pax or crew.

IMO, it doesn't matter if the 225 can fly for 5 minutes or 30 minutes with a total MGB oil loss. As it is, they only ended up with wet and possibly shaken up passengers, but another couple of minutes in the air and it could well have been a totally different outcome.

rab-k

10th May 2012, 20:50

Not even showing as an item on the BBC website now.

Au contraire...

BBC News - Footage of North Sea helicopter rescue (http://www.bbc.co.uk/news/uk-scotland-18018235)

tiLDdkwtLCA

BBC News - Flights suspended after North Sea helicopter ditches (http://www.bbc.co.uk/news/uk-scotland-18020646)

Bond Aviation Group has said it is suspending EC225 Super Puma helicopter flights until further notice.

It followed the ditching of one of the aircraft in the North Sea. The company said it ordered the suspension "for safety reasons".

The incident took place about 30 miles east of Aberdeen. All 14 people on board made it into a liferaft.

Nine were picked up and were flown to Aberdeen Royal Infirmary, arriving at about 13:45.

The remaining five were brought to Aberdeen by lifeboat.

An investigation is under way.

ARI accident and emergency consultant James Ferguson said: "I am delighted to say none of them are seriously injured."

He said they were treated for "minor bumps and bruises".

One was kept in for observation as a precaution.

The incident, which happened at about 12:15, has been described as a controlled ditching.

The helicopter was heading from Aberdeen to the Maersk Resilient and Ensco 102 drilling rigs - in the Jasmine field, operated by ConocoPhillips - when an alert was broadcast.

Jim McAuslan, general secretary of British Airline Pilots Association, praised the crew, saying it looked like a "terrific piece of airmanship from very skilled pilots".

'Future safety'
Offshore unions called for a helicopter safety group to be urgently reconvened.

A task force was set up in the wake of the 2009 Super Puma tragedy in which 16 men died.

The Unite Union and the RMT are demanding an urgent meeting of the Helicopter Safety Steering Group.

First Minister Alex Salmond said: "Thankfully it has been confirmed that all on board have been rescued.

"Incidents such as these remain very rare but do serve as a stark reminder of the dangers faced by those offshore workers who are required to use helicopters on a regular basis.

"Once all of those involved have been transferred ashore the priority will be for the appropriate authorities to investigate the causes of this accident and ensure the future safety of flying operations in the North Sea."

The incident response was co-ordinated by Aberdeen Coastguard.

HeliComparator

10th May 2012, 21:34

Ouch - that L2 downwash does look viscious!

Rollingthunder

10th May 2012, 21:37

Assuming it's still floating, although they may have not bothered to close the doors.....can it be recovered?

http://www.atroop412cav.com/tools/images/CH54_large.jpg

HeliComparator

10th May 2012, 21:43

Assuming it's still floating, although they may have not bothered to close the doors.....can it be recovered?

It can be recovered, but historically what normally happens is that a rescue craft comes alongside and punctures the float, whereupon it rolls over, then sinks. Then once on the bottom, another boat comes along and lifts it out of the water by the head. But with max weight 11 tonnes, and a fuselage full of water weighing 10 times that, the head is ripped off and once again it sinks to the bottom. Finally it is recovered having been totally trashed!

Alternatively like G-JSAR which found its own way to the beach unscathed but full of salt water and sand, it is then impounded by AAIB and not allowed to be hosed down with fresh water, so rapidly corrodes in the hangar due to salt water, pending completion of the investigation, until it is beyond economic repair.

So the answer to your question is "probably not"!

HC

DeltaFree

10th May 2012, 22:09

Hmm, would I want to get in an aircraft that had spent the night floating in the N Sea? Write it off! Or it will spend the rest of its life with untraceable snags.
Well done to the crew. Its a brave pilot who ditches a machine, but a madman who chooses to push the limits of disressed gearboxes. There must be some worries in Bond, 3 Pumas in 3 years doesn't look good but can the other operators say none of these could happen to them?
In Newfoundland the crew had reason to believe the gearbox might get them back to the beach, just because people say something it doesn't make it true. Just because your FRCs say a gearbox will give you 30mins doesn't make that true either.
I say again, WELL DONE to the crew.

industry insider

10th May 2012, 23:05

Of course it will be a write-off. Salt water trashes everything. Recovery is really only useful for investigative purposes. Parts could be used for maintenance training. Maybe the fuselage for HUET and the cockpit for a sim?

TeeS

10th May 2012, 23:29

Greetings II, British Airways S61 India Delta (I Ditch) survived its first ditching OK - helped by a boat hull; then there was a BCal 214 which returned to the fold after a swim.

Cheers

TeeS

industry insider

11th May 2012, 00:38

Tees, point taken, but as HC says, its all in the recovery. We will see. I remember ID, 1980 wasn't it?

SASless

11th May 2012, 02:01

A Helicopter dumps my butt in the noggin....and then some guy wants to winch me up into another one?

I think I would take the RIB to Platform thank you very much!

Flagging the next Bus to pass by might not the best plan for getting ashore however!

Rollingthunder

11th May 2012, 04:55

EC225 "Super Puma" $ 18M... undunked

RIB...Rigid Hull Inflatable Boat.... bounce...bounce...bounce...

McBraynes - Does not have a bus stop there.

industry insider

11th May 2012, 05:12

$18m? I don't think so.

HeliComparator

11th May 2012, 07:35

More, or less?

InsuranceGuy

11th May 2012, 08:43

Agreed Value Euro 19.5m:ok:

AndyJB32

11th May 2012, 08:48

Can't be an easy decision to ditch, so very well done to the crew for making a decision and carrying it out without any further incidents. Also, i was pleased to see on sky news that Bond management were very supportive of their crews' actions.

Alloa Akbar

11th May 2012, 10:06

@ MartinCh - Yes mate I was referring to the S-92 ditching, although it wasn't a technical comparison of the aircraft, just a reflection of the previous posters point about taking the decision to ditch and potential outcomes.

Personally my take is that faced with the instrument warnings and gauge indications, and the fact that there are 14 people alive and well today, then it was a great decision on the part of the crew.. to hell with the cost of an aircraft. €19M is small beer compared with compensation if you kill someone. (Not to mention that fact that the PIC will sleep easy in his bed at night knowing he did the right thing - as will 14 other families) :ok:

1helicopterppl

11th May 2012, 10:31

Various warning lights regarding main rotor gearbox oil loss led to a sequence of events, pretty sure the crew were not thinking of Newfoundland or Bond's own catastrophic gearbox failure which led to the loss of all on board.
The Capt is accountable for making a decision, in this case ditching, for the safe operation of the heli & its passengers. This was a safe ditching, all survived, at the moment the crew are professional heroes.

I hope Bond fully support their crew through the pending AAIB investigation.

PS. EC225LP, G-REDW.

cyclic

11th May 2012, 12:09

The crew did a great job and were thoroughly professional. Like all North Sea crews, they work under difficult conditions at times and on this occasion they showed how well trained they are and what a brilliant service they provide their passengers - I hope this is reflected by the press who are only to ready to dam everything and everyone.

industry insider

11th May 2012, 12:34

So more like US $25m if its 19.5m Euro things. An expensive day out for Bond's insurers. Bond premiums must be going up and up at the moment.

vfr440

11th May 2012, 13:15

II
And how mcuh do you think premiums would rise if this had been a total loss AND 16 lives..................?

To me, life is worth just an eensy-weensy bit more than an Insurance premium to be paid.

I'm an engineer, and if I had been on board I would have been VERY pleased with the Captain's decision.

I personally think they did a magnificent job - irrespective of the strictly financial cost. But then, you have your opinions, and I have mine.......
VFR

Lenticular

11th May 2012, 13:37

It would appear that a successful recovery of the airframe has taken place. Well done to the ship skipper and his team!:D

http://news.bbcimg.co.uk/media/images/60172000/jpg/_60172475_helicopter_arrives_bbc.jpg

pitpilot

11th May 2012, 15:05

So more like US $25m if its 19.5m Euro things. An expensive day out for Bond's insurers. Bond premiums must be going up and up at the moment.

Yes they will, but would have actually gone down after the first accident as in theory the likelihood of another accident in these aviation situations is greatly lowered. In reality this hasnt been the case!:(

Rollingthunder

11th May 2012, 18:31

This is actually a good story..... all saved through good piloting and excellent SAR.... maybe all due to faulty instrument light....maybe.... and a recovery!!!...but good news when compared with Indonesia Kapaleterbang.

teej5536

11th May 2012, 19:08

@rollingthunder:

Why the speculation over a faulty light? Is it not fairer to assume, at this early stage, that what we have is a genuine emergency to which the crew responded appropriately (and commendably). I expect the commander's decision to ditch would not be based upon a single indication. I read earlier in this thread the mention of "a light, a noise, and a smell".
Any pilot should always verify any annunciation with a secondary indication. I expect this would be much more likely, as the suggestion of a faulty "light" trivialises and -frankly- mocks the decision of the commander of this flight. A man (or woman) who saved 14 lives.

griffothefog

11th May 2012, 19:20

There is no way an experienced captain would ditch a serviceable aircraft with just a low main gearbox pressure light/indication. Yes descend to low level put out the appropriate calls and slow down while you monitor for any other indications, but ditch based on 1 light.... bull****.
I bet the crew did a very professional job... Well done guys :ok:

HeliComparator

11th May 2012, 20:16

Yes descend to low level put out the appropriate calls and slow down while you monitor for any other indications, but ditch based on 1 light.... bull****.

Not based on 1 light but several lights/captions and a gauge (see my post #45). If you are suggesting that one waits for other signs such as yaw kicks, grinding noises etc then that is very foolish. Hopefully you are not suggesting that but your post could be read either way.

Try jumping out of a low flying heli at 100' doing 50kts and see what the impact with the sea is like - you might just as well be at 10,000' and 150kts. One has to make the decision to ditch based on the multiple and redundant indications available in the cockpit, not ignore them just because you can't feel / hear anything else going on. Apologies if I am ranting to the converted!

Camper Van Basten

11th May 2012, 21:46

I'm led to believe there was more to it than purely cockpit indications, as you would expect given the drastic measures taken by the crew. Either way, respect to all involved for a proffesional ditching, rescue, and aircraft recovery.

:D

industry insider

11th May 2012, 22:03

Vfr 440,

I made a comment on Rollingthunder's value. I then said that Bond insurance premiums would rise, which will make it harder to bid competitively.

I did not comment on the job done by the crew or the value of a life. As ditchings go, and I have seen a few, this one was very successful.

Now, like everyone else, I would like to know why 40 years into the NS industry, and more technology, policies, procedures, modern equipment, aviation advisers etc. why a nearly new helicopter operated, flown and maintained by an experienced helicopter operating company, ends up in the water. As an industry, we need to do better, don't you think?

Please read the lines, not between them.

topendtorque

11th May 2012, 22:06

The captain's primary responsibility isn't to maximise profitability for the shareholders, or even to minimise the cost of an aircraft recovery; it is to maximise and ensure, as far as is possible, the safety of the passengers.

I think this is an excellent bit of prose, not the way I usually put it, but this could be framed and headed with, "if your company wants a good reputation this is the rule" or words to that effect and hung in the boardroom.

having now just read post 74;

I then said that Bond insurance premiums would rise

I could add, just try killing them all and see what happens to the blessed insurance.

SASless

11th May 2012, 22:16

Let's see here....I am in a Bond helicopter....and have indications of MGB problem.....so what if my outfit had a nasty event not so long ago....nope...that would not weigh on my mind.....why not even the Cougar 92 thing would enter into my mind....nope not me!

In a worst case scenario....ditching may have been premature....but not WRONG! Worse case in this instance....hypothetically speaking....would be if there was no "need" to ditch.

These are qualified guys driving that machine...and if they decided they needed to Ditch....they did the RIGHT thing folks. No one just plunks a helicopter into the oggin for giggles!

Until you know what the Crew was dealing with....lay off second guessing them!

That can come after the AAIB has their say!

aspinwing

11th May 2012, 22:23

SASLESS That just about covers it.

Hummingfrog

11th May 2012, 22:56

This seems to have been a text book controlled ditching carried out by a professional NS crew. There must have been a good briefing of the passengers (who would also be well trained) prior to the ditching as from the post accident pics it seems that nobody inflated their lifejackets. This would indicate no panic - hence well trained and briefed passengers and an orderly evacuation from the helicopter into the 2 liferafts. Did they even get wet??

Well done to all.

HF (retd)

Jet Ranger

11th May 2012, 23:29

Good pilots (and well trained) did a great job!:D

Rollingthunder

12th May 2012, 04:16

I made a comment on Rollingthunder's value.

Didn't know I had one.

Turkeyslapper

12th May 2012, 05:41

I think the question is, 'Is a light, a ditching decision?

I don't fly these particular machines however out of interest, what does the flight manual say in this particular case? Does it say Land as soon as possible, immediately etc

Does it say check for secondary indications such as x, Y, and Z? What guidance is provided? Many aircraft I fly dont really expand beyond a simple Land ASAP for several malfunctions including the loss of a single hydraulics system.

Sure systems knowledge, common sense and all that needs to come into play when making ones difficult decision to ditch, however where do I stand say if there is only one indication (land as soon as possible/immediately whatever) and I decide to press on awaiting secondary indications and then it all goes pear shaped very quickly and I end up in the water in an uncontrolled fashion?

We have similiar discussions in our crew room regularly and everybody has their own opinions?

Any Hoo....well done to the crew :ok:

Cheers

Epiphany

12th May 2012, 15:16

what does the flight manual say in this particular case?

The only people who know what this particular case was are the professional crew who performed a very successful ditching. If all back-up systems for MRGB lubrication failed then the ECL is quite unequivocal. 'Land Immediately' means just that.

G-CPTN

12th May 2012, 23:06

BBC News - Ditched Super Puma 'suffered main gearbox oil leak' (http://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-18043685)

A helicopter that ditched in the North Sea on Thursday suffered a main gearbox oil leak, BBC Scotland understands.

Air Accident investigators are due to begin examining the Bond EC 225 Super Puma, which was brought back to shore at Peterhead on Friday.

The pilots performed a controlled landing off the coast of Aberdeen. All 14 people on board escaped serious injury.

Operators Bond said it could not comment on the cause of the incident.

Bond has temporarily suspended flights of the same type of aircraft until a "detailed root cause investigation" is carried out into the incident by officials from the Air Accidents Investigation Branch and Eurocopter.

In a statement on Friday the operator said: "Bond Offshore Helicopters Ltd is committed to the safe operation of the company's entire fleet including the EC225 and for that reason flights can only recommence once they have completed a detailed analysis of the incident."

The helicopter was heading from Aberdeen to the Maersk Resilient and Ensco 102 drilling rigs - in the Jasmine field, operated by ConocoPhillips - when an oil pressure warning light came on.

Members of the Helicopter Safety Steering Group are due to meet on Monday to discuss the incident.

Floppy Link

13th May 2012, 08:47

Interesting account on Flyer.co.uk (http://forums.flyer.co.uk/viewtopic.php?f=1&t=76825)

I was on the chopper that followed this one out of Aberdeen on my way to work...

About 15-20 minutes into the cruise, we started a decent and turned away from our cruise-course. A couple of minutes later the crew announced that we were decending and trying to locate another helicopter "circling below". About a minute later the Bond SuperPuma became visible out of my window floating in the sea with the rotors still turning and all the bouyancy floats deployed. An S92 was circling the chopper closely a few hundred feet below as we started to orbit the scene to the right. The crew announced that we and the S92 would remain on the scene to radio relay what was happening. As we circled the ditched SuperPuma the rotors came to rest and I was able to watch as the liferaft was deployed and used by the guys after exiting the chopper.

The crew then announced the S92 needed to depart the scene due fuel state, but we would stay on station until the rescue assets arrived, and that everone from the downed SuperPumer was OK and safely aboard the liferaft. We then continued orbiting the downed chopper and the liferaft, a couple of times approaching to within 50ft and hovering just above the sea to display/read messages to/from those in the liferaft. The crew continued to inform us about what was happening as we circled the scene for over an hour and a half and were joined by a fixed wing higher above. The Bond Jigsaw (from an offshore platform) and an RAF Seaking (from Bulmer) arrived almost simultaneously and I was able to see both arrive on station and the Jigsaw approach and hover over the raft, commencing the rescue as we departed back to Aberdeen.

Once back at Aberdeen our heli-crew came over and de-briefed us about what had happened. They confirmed that everyone was OK and had been rescued successfully. They told us that they had heard the bond helicopter crew report a gearbox oil pressure problem and were returning to Aberdeen, when there was some smoke/fumes and/or leaking fluid reported in the cabin (unclear at the time), so the bond crew opted for a controlled emergency landing on water.

Regards, SD..

Woolf

13th May 2012, 09:02

Special bulletin now released:

Air Accidents Investigation: S2/2012 EC225 LP Super Puma, G-REDW (http://www.aaib.gov.uk/publications/special_bulletins/s2_2012_ec225_lp_super_puma__g_redw.cfm)

Summary:
The crew of the helicopter carried out a controlled ditching following indications of a failure of the main gearbox (MGB) lubrication system and, subsequently, a warning indicating failure of the emergency lubrication system. All passengers and crew evacuated the helicopter into a life raft and were subsequently rescued. Two passengers sustained minor injuries. The investigation has identified a 360° circumferential crack in the bevel gear vertical shaft in the main gearbox, in the vicinity of a manufacturing weld, causing disengagement of the drive to both mechanical oil pumps.

Well done that crew!

Vie sans frontieres

13th May 2012, 10:27

That'll be what's meant by multiple indications! Good work getting it down from 3000'. :ooh:

212man

13th May 2012, 10:41

The helicopter was in cruise at 3,000 ft with the autopilot engaged and at an approximate speed of 143 KIAS, 34 nm east of Aberdeen Airport, the crew were presented, almost simultaneously, with the following indications:

- WARN red light and aural gong
- MGB.P1 caption illuminating on the Central Warning Panel (CWP)
- CAUT amber light
- XMSN caption illuminating on the CWP
- M.P2 and S/B.P3 illuminated on the vehicle monitoring system (VMS)
- SHOT illuminated on the MGB control panel
- Zero indication on the main gearbox oil pressure gauge.

In addition, CHIP illuminated on the VMS and the MGB oil temperature started to increase.

The commander assumed control of the helicopter, reduced speed towards 80 KIAS, turned back towards the coast and initiated a descent. The crew activated the emergency lubrication system.

During the descent, the MGB EMLUB4 caption illuminated on the CWP, for which the associated procedure is to land immediately. The commander briefed the passengers and carried out a controlled ditching.

Out of interest, what does the 'SHOT' caption indicate?

Well done to the crew :ok:

Fareastdriver

13th May 2012, 10:42

BBC reporting that the oil pressure loss was caused by a crack internally on the rotor shaft. No idea of the 225's oil flow routing so cannot expand.

Out of interest, what does the 'SHOT' caption indicate?

It's French for 'FU@@ED'.

More onthe story here.

BBC News - Bond Super Puma ditching caused by gearbox crack (http://www.bbc.co.uk/news/uk-scotland-north-east-orkney-shetland-18049795)

soggyboxers

13th May 2012, 10:51

Would all the naysayers now like to join in wishing hearty congratulations to the crew of G-REDW for successfully completing a textbook ditching, resulting in the safe recovery of all passengers and crew and leading to the recovery of their aircraft so the AAIB can get accurate information as to the cause. :ok:

Thanks to HeliComparator for his early insightful and reasoned posts which were spot on.

A very well done to the crew and to their management for being supportive during the usual Sky News and BBC reports looking for someone to blame and coming out with all the "what-ifs" and other disaster scenarios :mad:

AAKEE

13th May 2012, 11:01

Yepp, Very well done :)

forwardassist

13th May 2012, 11:08

So with the report stating that it was a crack in the gearbox that caused the MGB pumps to fail, are the other operators going to ground their aircraft to check for this problem or are they going to continue flying? I haven't seen anything with Bond written on it leave the airport today, so have they grounded all types?

cyclic

13th May 2012, 11:21

You can always check all three companies schedules online and see if they are flying. What it doesn't say is which type/variant they are flying with. I would hope that all the operators have read the initial report and are formulating a plan.

I'm sure HC will come up with some ideas as to why the SHOT indication was also showing.

Woolf

13th May 2012, 11:22

Sky is reporting that Bond have suspended flying on both the EC225 and also the L2. CHC and Bristows are apparently still flying as normal.

I have no insight knowledge but my gut feeling says it might be worth loosing one or two days of flying until an official EASA / Eurocopter announcement has been made just to be on the safe side. Not pleasant for people stuck offshore but it would certainly bring some peace of mind to passengers and crews alike.

heliwanab

13th May 2012, 11:25

would the AAIB not issue a warning to inspect,ground until further notice after the inspection showed cracks?
Or would that come from Eurocopter direct?

cyclic

13th May 2012, 11:27

It isn't "cracks", it is one 360 degree crack around a shaft. The AAIB has no authority to ground aircraft, it can only give advice to the authority.

SASless

13th May 2012, 11:27

At the risk of starting an old War all over again....does the 225 have a MGB design problem? I know all about the zillion hours X 10 to the ump power....and how the Laws of Probability work.....we have had that discussion too. But notwithstanding all that....is it Bond or the 225 that has the problem? Is the fix a simple Exorcism at the Bond Hangar or something bigger at play?

I am making no suggestions....just asking a question.

If it was a 92 involved....I know exactly where this discussion would be right about now.....and am just wondering why not with the 225?

I accept the 225 was seen as superior because of the Emergency Lube system but now we see that can also be done in by events. Added to the other problem identified with the MGB design....is the 225 as safe as once assumed?

cyclic

13th May 2012, 11:35

SAS

I think Eurocopter will need to come up with answers and quickly. Until that time there are going to be numerous theories and I would love to get into them now but because of how the press works over here, I am keeping my ideas offline. The exorcism does sound like the best one so far though!

heliwanab

13th May 2012, 11:38

cracks or crack the failing of the drive to both pumps suggests the separation of the shaft. perhaps not enough for any form of gap as such but is the component up to task or as SASless suggests, does the 225 have a problem?
The outcome is what matters for sure. Well done to the crew :D

pohm1

13th May 2012, 11:40

If it was a 92 involved....I know exactly where this discussion would be right about now.....and am just wondering why not with the 225?

I think the main reason for so much of the discussion and argument around the S92 was the lack of clarity as to what the aircraft was or wasn't capable of doing with no MGB lubrication, not the lack of a backup lubrication system. There is no doubt as to what to do in this case with 332/225 range.

P1

The elephant

13th May 2012, 11:42

Excellent work, the answer for the loss of px in the Mg/b has been found. Let us hope this is the answer to the catastrophic failure as well, put some minds at rest. Interesting that Bond have suspended all 225 and L2 flights ( BBC report ). Great action by them, will this happen across the board I wonder? I guess a mandatory grounding will be imminent anyway.

coatimundi

13th May 2012, 11:50

Camper Van Basten

13th May 2012, 12:15

Can someone explain how this internal crack led to an external oil leak, as reported in yesterday's media?

TRC

13th May 2012, 12:19

The investigation has identified a 360° circumferential crack in the bevel gear vertical shaft in the main gearbox, in the vicinity of a manufacturing weld, causing disengagement of the drive to both mechanical oil pumps

Driving both oil pumps from the same shaft - the main and stand-by - evidently enables a single failure to cause complete loss of oil pressure.

Am I being old fashioned by suggesting that any stand-by system should be totally seperate from the main system, and any failure (short of a catastrophic xmsn disintegration) that causes the main to fail shouldn't affect the stand-by?

PlasticCabDriver

13th May 2012, 12:21

"SHOT" is simply the wording on the Emergency Lube activation button on the overhead panel. It illuminates (I think, if someone has access to the FM and can correct me please do!) when 2 conditions are made: ac is in flight and the MGBP caption is activated, which was the case here.

Vibrations change on helicopters all the time. I don't know if similar systems are installed offshore, but I'm sure if one of them showed a similar change the immediate action would not be "quick, shut it all down, take it all apart and check it" but "interesting, we'll keep an eye on that". The procedures for doing so are well laid out in the aircraft maintenance documents, and in this case it was being done "in accordance with the manufacturer’s maintenance manual."

This is an interesting last line from the report:

"Detailed examination.......of the reason for the indication of a failure in the emergency lubrication system continues."

Not "failure of the emergency lubrication system" but "indication of failure in the emergency lubrication system"? Maybe I read too much into it but are the AAIB currently thinking that the Emblube system was in fact working, but the indications were that it was not, leading the crew to "land immediately".

Obviously no criticism of the crew here, the Emergency checklist is unequivocal in this case and ditching was the only and correct course of action, which they did perfectly.

SASless

13th May 2012, 12:38

Cyclic.....I will grant 24 hours grace before reminding some folks of past statements perhaps....as this latest event is certainly going to cause (or should at any rate) some serious reconsideration of the relative merits proclaimed so loudly and at length in the past.

I wonder if other operators are having similar problems with Main Gear Boxes?

Bond appears to have grounded their fleet.....why would they do that and other Operators not do the same.....what do the other Operators know that Bond doesn't? Are the Bond Aircraft unique? Are the other Operators carrying out special inspections and/or reviews of HUMs data (or both)? Has there been any AD action by Eurocopter or any of the Administrators? Any industry wide notifications yet?

Bond easily could be the tragic victim of Fate but one does have to wonder if there is some organic cause similar in nature to the Norwegian S-61 Spindle failures many years back. That had to do with an operational technique that was unique to them. Is there something similar going on here?

Not suggesting there is but merely raising one of many questions that begs asking. i would think the AAIB will take that as one of the many lines of questioning they will apply to this and other events re the 225/L2 MGB design.

Helicopters suspended as gearbox fault blamed for SuperPuma ditching | News | Aberdeen | STV (http://local.stv.tv/aberdeen/news/99554-helicopters-suspended-as-gearbox-fault-blamed-for-superpuma-ditching/)

HeliComparator

13th May 2012, 13:48

Seems almost certainly a manufacturing defect of the shaft (AAIB says crack in the vicinity of a weld joining 2 halves of the shaft). I see EC now has a bulletin on TIPI indicating that there is a batch of suspect shafts - I believe a recent batch. Fortunately we don't have any of that batch on our fleet so we are not affected.

PCD - yes I noticed the wording as well, and of course they said some glycol was found in the MGB. There are 2 pressure switches, one for the bleed air and 1 for the glycol. After pressing the SHOT button, the system waits 20 secs and then expects both pressure switches to be showing pressure. If not, MGB EMLUBE illuminates and it is Land Immediately.

Trouble is those pressure switches are only activated with a real emergency or during maintenance, the rest of the time they do nothing except sit there and degrade. When we first got our fleet, the maintenance interval was 750 hrs and we routinely found 1 or other switches inop. We reduced the check to 375 hrs and I think we change them at 375 hrs(?). I am not sure whether this is our company procedure, or whether it is now manufacturer's procedure. In any case, chances are that the EMLUBE was working but they had indications of failure. In that respect it is a poorly designed system.

We just fleet checked the pressure switches and all ours were found to be working correctly.

This would explain oil leakage - with the engine bleed air pressurising the gearbox, oil is forced out of every orifice and low pressure seal making a right mess. (it has happened, though fortunately only on the ground!)

HC

HeliComparator

13th May 2012, 14:28

Coatimundi

HUMS is a fantastic safety tool but not perfect. One problem is that there is so much data, that a "top level" reporting system is needed to interface between all the data and the engineers. This reporting system uses various thresholds and triggers - anything below the trigger / threshold is not presented "in the face" of the engineer, but can be viewed by delving into the raw data.

The thresholds have to be set somehow, and in the early days of HUMS it was mostly guesswork. Various events and experience with false alarms etc have allowed the thresholds to be refined over the years. But since there has not been a previous failure of this shaft, there was no information to allow refinement of the appropriate thresholds. Now there is, so hopefully another small improvement to HUMS will result.

For the time being, the operators now know to keep a close eye on this parameter pending refinement of the thresholds.

HC

diginagain

13th May 2012, 14:29

HC -my thanks for the clarification on those points. As a former pilot I have been asked to speak with my colleagues on my offshore installation this evening, and your input is much appreciated.

LastMinute

13th May 2012, 14:43

Driving both oil pumps from the same shaft - the main and stand-by - evidently enables a single failure to cause complete loss of oil pressure.

True, but the risk of that shaft detaching from the upper part of the main gearbox drive shaft (which is a single point of failure anyway) may have been analysed as being lower than that of any alternative design.

(There’s a gearbox diagram on the G‑REDL accident thread here.)

jonnyloove

13th May 2012, 15:02

With the AAIB initial findings does that mean the helicopter will be released back to Bond..??

Will she fly again..?:)

Rubber Dog

13th May 2012, 20:04

I would be surprised if it comes back into service. I think the damage and cost of repair would make it a write off.
I also noticed that the BBC tv news today mentioned the controlled ditching (they may have said landing) however the newsreader felt the need to offer his own comment and call it "a crash landing to the rest of us". Irritating buffoon.

NorthSeaTiger

13th May 2012, 20:09

Extremely Remote ?

jimf671

13th May 2012, 20:57

We were told offshore some time ago that HUMS was a wonderful addition to helicopter safety. With this in mind, would someone care to comment on these words from the Interim Report:

These sensors had recorded increasing vibration
levels during the previous few flying hours prior to the
accident flight and were being monitored, in accordance
with the manufacturer’s maintenance manual.

It has raised questions out here on Safety Meeting Sunday - it would be good to give the troops some more feedback.

The following is from "AAIB Bulletin No: 8/2004" referring to the L2 G-JSAR incident, 22 February 2003. Though the actual failures are different, I find the similarities in the monitoring scenarios somewhat concerning.
On 21 February the RMS parameter threshold was breached, - this is also shown in Figure 4. This is the Root Mean Square of the signal and is a measure of the total energy, the value of which will tend to increase in the event of damage to the component. The EuroARMS Training Manual notes that defect detection using this parameter occurs "at a fairly late stage" in the damage process. Following a review of the thresholds, it was decided to continue monitoring both the RMS and the RMSR parameters. The MGB chip warning and oil cooler drive shaft failure occurred on the following day, some 21 flight hours after the initial alert on 21 February. The final EuroARMS data was sampled only 2 minutes prior to the chip warning.

HeliComparator

13th May 2012, 21:14

jimf

I think it would be mistake to read into these texts that operators are not bothering too much about HUMS alerts. The nature of the HUMS beast is that it is uses external accelerometers to monitor and extract vibration signatures for individual shafts, gears and bearings within the tranmission (ie it is non-invasive) all in a pretty nasty environment of heat, dirt, salt, oil and grime not to mention overall flight vibration (not to be confused with transmisison vibration).

The net result is a relatively high false alarm rate, or at least a need to be circumspect in not jumping in with both feet when the HUMS squeaks, without thinking carefully about it.

The false alarm rate is much lower these days - as I mentioned earlier, HUMS is an evolving science (or maybe an art!). It is not perfect, but I get nervous when it is implied that "it don't work so it ain't worth having" because whilst far from perfect, it is still a quantum step forward in flight safety.

In our company we have a couple of very experienced engineers whose sole job is to keep tabs on the HUMS systems, even though these are supposed to be "user friendly" to line engineers, and we do take any such trends very seriously, but at the end of the day a qualitative judgement has to be made as to whether it is a significant issue or not. 99% of the time we get this right, and it doesn't make the papers. Just occasionally it goes wrong and then does make the papers!

jimf671

13th May 2012, 21:52

I take your point HC.

coatimundi

14th May 2012, 06:51

Thanks to everyone for their comments on this - much appreciated by the offshore workforce :ok:

diginagain

14th May 2012, 07:25

^ ^ ^ ^
What he said. :ok:

HeliComparator

14th May 2012, 07:40

Just as a postscript to the HUMS issue, apparently the user can adjust the thresholds at which alerts are generated and we have now significantly reduced the thresholds for the oil pump drive parameters as of this morning.

In our company, we have always downloaded and analysed the HUMS when we return to base, even when it is a rotors-running turnround (as it often is). On the 332L2 this is not possible since there is no method of forcing a termination of the HUMS session onto the card whilst rotors running. The ability to rotors-run download is something we insisted on before taking delivery of the first 225 (and I recall we had to pay EC extra to develop it!). However the manufacturer's procedures do not require HUMS to be dowloaded like this - their view is that once every 25hrs is adequate. I am not sure whether other operators routinely download on every arrival at base - it would be interesting to hear if they do?

In my view the manufacturer should be more proactive in encouraging operators to make the most of HUMS. For the time being, they regard HUMS as an "optional extra" (although of course it is a regulatory requirement for N Sea) and I think it is time this view changed!

Peter-RB

14th May 2012, 08:36

With the small amount of information regarding a 360Deg crack near to or in the vacinity of a production weld joining two parts together , could indicate a production problem related to inncorrect stress relief/ normalising after heat induction caused by welding, unless carried out almost like a scientific test normalising will cause either embrittlement or loss of tensile strength.

But for so many Helis to have the same fault would need all of them to have been fitted with the same sort of faulty shaft/bevel gear from the same possibly faulty batch of shafts, which almost seems to be impossible..!

Does anyone know if this affects the Military Pumas?

Peter R-B
Lancashire

diginagain

14th May 2012, 08:45

But for so many Helis to have the same fault would need all of them to have been fitted with the same sort of faulty shaft/bevel gear from the same possibly faulty batch of shafts, which almost seems to be impossible..!

I'd be interested to see the evidence upon which you are basing this claim.

HeliComparator

14th May 2012, 09:04

Certainly none of Bristow nor CHC aircraft in Abz have these suspect batch of shafts, not sure if Bond do but there are only 9 affected shafts in existence worldwide (and not all those necessarily installed in an aircraft). The shaft design is a different part number than installed on the 332 and 330, though I believe retrofit is possible at least on the 332. All the shafts are visually very similar, the ones fitted on the 225 have modified treatments as the primary difference.

diginagain

14th May 2012, 09:27

Just as I thought; thanks HC. Are you picking-up the slack, so-to-speak? I only ask as I'm scheduled to be inbound from the Northern-most reaches tomorrow.

Alloa Akbar

14th May 2012, 09:37

HC- I have been out of the HUMS arena for a few years now (Formerly Systems Engineer on IHUMS) back then (Early part of the Noughties) we had pretty good control and interpretation of the systems data output, however even in mature airframes, we had the odd failure which was on something we hadn't actually been monitoring directly.. anyway, my question..

The CAA funded a study (carried out by Smiths) to develop a "neural networked" HUMS system which would be smart enough to evolve its own thresholds levels. What was the outcome? I was recently at an HM Gov Tech Strat Board competition launch where they invited bids for funding to develop HUMS systems, although after I questioned the TSB staff it turns out that they felt it was a good subject matter, although they had no idea that in fact it was already a mature system as they had not carried out any research.. :rolleyes: Nor had they had any contact with CAA SRG on the subject :ugh:

So are you guys still plodding on with the systems we had ten years ago, or has there been significant technology advances in terms of data collection, processing and interpretation? Is SMART HUMS any nearer reality? I mean real advances here.. not just a sexy new name or a swish new display format on the PC's. I look at advances in data processing and application engineering in areas such as communications and entertainment and can't help but think HUMS should have evolved at the same rate by virtue of the same architecture?

Interested in yours and others opinion on the matter.. :ok:

HeliComparator

14th May 2012, 09:41

We will do our best to keep our customers happy and pick up some slack, but there is certainly not sufficient spare capacity to replace all Bond's flights so I am afraid some disruption to you guys is inevitable.

diginagain

14th May 2012, 09:43

That's fair; I had heard that one consideration might be S-92 to Scatsta followed by fixed-wing to Abz. Doubtless, minds greater than mine are at work with a solution. Thank you.

500e

14th May 2012, 11:09

Interested to see the HUMS graph showing discrepancy's.

HeliComparator

14th May 2012, 11:50

A A

That is a good question and one I would be asking of my company if I were an offshore safety rep. The short answer is no, we are not using it.

The system you are referring to is AAD (advanced anomaly detection) and I think it is a good system, designed to sit on top of existing HUMS systems and analyse their outputs looking for anomalies that don't necessarily breach set thresholds. I don't know why it has not been adopted, possibly commercial reasons?

I do know that Eurocopter are working on their own such system which should be out this year for the M'ARMS aircraft (225 and 155) which will be a start.

HC

TrisG

14th May 2012, 12:39

Had a discussion offshore about the current issues with the helicopters. A question was raised about how ofted the gearboxes are opened up and the gears actually close visual inspected and NDT inspected for signs of fatigue or damage etc?
A person stated that the gearboxes had to be sent back to manufacturer for this to be carried out - I personally think all of the Aberdeen based operators surely would use their own in house mechanics & inspectors to do this, unless there was a requirement for a metallurgical inspection etc.

Any information is very much appreciated.

Thanks

212man

14th May 2012, 12:48

It sounds like some of the research NASA has been conducting into FDM. Rather than set arbitrary limits, why not look at historical data and define what is normal. Then look at the 1 and 2 sigmas etc to set the triggers. That way you are truly looking at deviations from the norm.

Alloa Akbar

14th May 2012, 13:46

I think also the speed of response of the support teams is crucial to good diagnosis of a problem.

When we used to see gradual increases in vibe levels we were never quite so alarmed as we were when we saw a step change in levels, however step changes were in a vast majority of cases due to a change of sensor or cable etc, and so by the time that question has been answered, the aircraft may have done several more flights.

The AAD system was always designed to support HUMS data integrity, but of course too many had their own agendas and commercial reasons for not integrating it. The big question was of course data ownership, and a manufacturer such as Meggitt were never going to willingly hand over data to Smiths which could be used to aid their HUMS systems development.

Sikileaks - The benefit of one global system and information sharing. Up in Aberdeen at one time the operators HUMS Managers were looking after anything up to 3 different HUMS systems. Great name by the way, I am nominating you for the Moniker of The year award!! :ok:

Lonewolf_50

14th May 2012, 15:06

For the crew: Hand Salute! :ok:

For HC: thanks for your HUMS insights.

Aloha, for your HUMS points as well.

For sikileaks: thanks for that insight as well.

Shell Management

14th May 2012, 18:57

Once again the oil and gas industry lead the way:)
http://www.oilandgasuk.co.uk/downloadabledocs/292/j_Andy_Dollin.pdf

And well done to the crew for compliantly following the flight manual.

Scotsheli

14th May 2012, 19:34

An operator can change the major modules of the gearbox on the "line" (i.e in a normal level maintenance facility as at Aberdeen), but you cannot disassemble the gearbox and inspect every component as you describe, for good reason however.

If you were to visit a gearbox overhaul facility you would be amazed at how sterile the environment is – it’s a temperature / humidity controlled "white coat and gloves" zone which is forensically clean. You would not wish to take a gearbox apart in anything other than that environment because in so doing, you introduce way more risk than the benefit from completing an inspection. All of the Aberdeen operators use specialist facilities to complete this work, two of them use Eurocopter.

The gearboxes and their components are managed closely, and the component “lives” (how many hours the components can operate for before inspection or retirement) are set at very conservative levels. The TBO (time between overhaul) for the EC225 main transmission is 2000 flight hours and given the average aircraft utilisation in Aberdeen , that’s an overhaul, and inspections just like the ones you describe, just about every year.

Hope that gives you some comfort.

Scots.

Scotsheli

14th May 2012, 19:37

....and Mr. Management.

From where i've been sat this last 72 hours there's been little that could be described as "leading" going on from your side...

Fareastdriver

14th May 2012, 20:05

Who rattled SM's chain?

Brian Abraham

15th May 2012, 03:17

Fair go on SM chaps. ;) The document does sayimplementation on the fleet will not happen without commitment & funding from the industryandThe commitment of the Oil & Gas industry is now needed for implementationWe all know how the industry (oil) leaps to the fore when coughing cash for safety.Once again the oil and gas industry lead the wayThat'll be the day.

Alloa Akbar

15th May 2012, 07:32

SM- Interesting albeit very top level ppt. Good to see that the quality of data is being addressed and I like the data mining and reasoning approach as long as it is implemented and supplemented by the judgement and expertise of the people with years of HUMS data interpretation experience.. The guys who ask questions that computers will never think of. There is a balance to be found and we are obviously still a long way from the end game, but very good to see that steps are still being made to drive technology along the road.

My original point which I didn't make clear though was taking this type of thing as a baseline, and given the advances in modern communications methods - Would it be unrealistic to envisage the guys back in Aberdeen being alerted to, and subsequently able to monitor live real time data events as they occur as is done in F1 racing? I know the distances between the vehicle and the groundstation are far greater, but then if we can have in-flight broad band available, why not??

terminus mos

15th May 2012, 08:22

Alloa

Great idea, real time HUMS data and even a live external camera into a helicopter operator's operations centre would be a step forward in my opinion. But there would have to be some boundaries established. The same camera feed to go to the cockpit to provide pilots with an external view.

Be careful with SM, he is not S.

topendtorque

15th May 2012, 08:51

but then if we can have in-flight broad band available, why not??

Many people in other industries would be astounded if such were not being done now.

e.g. 1) Detroit diesel has for many years been monitoring prime mover engines on road trains operating all round OZ. Says one driver, 'once you get out of Queenslad where the hills are around Mt Isa and get to the flat barkly tableland in the Territory, all of a sudden the fuel pump settings would change and the 120 tonne truck would fairly leap ahead.' All done from head office via satellite.

2) A couple of years ago Caterpillar had sold a most ginormous brand new wheeled loader to an Argyle diamond mine contractor. One day it stopped. Mechanics from the agents all over OZ could not fix it no matter how hard they scratched the head. Finally someone rings caterpiller-merica.

Came the response. "Godamn, I caan't see it, where is it?"
'Well we pulled the axles out and dragged it into the big shed mate, eh!'

"Warrllll," says godamm, "you jus drag that there machine outta the shed where ah can see it and in twenty minutes it'll start."

and it did. cool eh?

Alloa Akbar

15th May 2012, 09:15

One of the big issues we always faced was the level of information given to the Pilots in real time and how that was used in their decision making processes. Back then (10 years ago) the argument was that the warnings generated by HUMS were never considered reliable enough for a Pilot to decide on whether or not to ditch, however my view was always that HUMS data presented to the Pilot in real time (Such as a cockpit display) should be read in conjunction with other indications. I believe the general jist of the GE system perhaps provides better quality and granularity of data to be able to be used in such a fashion. That said there is always a scenario where something like a crack may become terminal before any other supporting indications become apparent, in which case, real time monitoring and support from base becomes crucial.

Perhaps a broad review of how HUMS is implemented is needed as much as the new technology. Maybe greater training - by which I mean train Pilots and all LAE's on the HUMS systems to a greater degree rather than have each company having a "Yoda" in the HUMS management office. Either that or expand the HUMS operation to more of a monitoring and control centre. It shouldn't need 24/7 user input staring at screens, but a method of alerting the user to events as they occur.

Incidentally.. in my scenario, we still need the "Yoda's" to oversee and manage the implementation :ok:

500e

15th May 2012, 10:36

http://www.pprune.org/rotorheads/369622-main-gear-boxes-grand-lottery-4.html#post4865130
Would suggest a read of this thread again, seems we are on the roundabout regarding HUMS.

SASless

15th May 2012, 14:07

Who picks up the Bill for this one?

Bond, their Insurance Carrier, Eurocopter, or whoever it was that made the bad shaft (if not EC)?

Banksman

15th May 2012, 14:11

What A/C are Bond using today for flights too Hummingbird and Beatrice A as thought all 225/L2 grounded:confused:

teej5536

15th May 2012, 14:26

A139, might be from Dancopter?

TrisG

15th May 2012, 16:25

Thanks for the response Scott - A lot of people are wondering why the gearbox on the heli in question wasnt investigated further?
We've been informed the pilot had reported some vibration anomalies on an earlier flight.

Some of us think a year is too long between inspections.

Thanks all the same.

ironchefflay

15th May 2012, 18:21

Engineers arent sitting around in our place while the aircraft are flying. usually one or two on maintenance of some kind while others are working the line. not much time to be watching telemetry.

Since the oil/helicopter companies dont like paying for engineers as it is im not sure whos going to stump up for the extra people to expand the hums/telemetry dept.

shame though because its great those examples of detroit diesel and Caterpillar and also some luxury car makers do that too.

wire_less

15th May 2012, 18:31

Yeh! there is a separate tank outside the MGB which contains Glycol, in the event of a main and emergency pump failure, the glycol or emergency lub system is selected which will lub the gearbox and hopefully get you back safely, think in this instance the oil and the glycol was coming out of the gearbox, and eventually the emergency lub system failed too, giving them no option but to ditch.

Scotsheli

15th May 2012, 20:07

Be assured, the gearbox, like the whole helicopter, is inspected at one level or another, daily. In fact, if you count the HUMS too, almost constantly.

I know there is a lot of discussion going on about how effective HUMS is, and clearly (like everything) the technology still evolves, but in truth it’s a powerful tool which helps engineers monitor the condition of critical components on an ongoing basis and helicopter flight is safer for it.

Next time you land, perhaps ask your helicopter company if they could offer you a few minutes to show you around engineering and tell you how the maintenance plans work. You’ll be comforted, whoever you are flying with.

Lonewolf_50

15th May 2012, 20:17

And well done to the crew for compliantly following the flight manual.
Next time, won't you please wipe the drips of sarcasm before you hit the "submit reply" button? You got my screen all wet.

teej5536

15th May 2012, 22:12

Tris:

Curious to know who "we", are? And by whom were you all informed (RE: the pilot reporting vibration anomalies)?
Sounds like a juicy bit of gossip there.

industry insider

15th May 2012, 23:14

Bravo73

16th May 2012, 00:36

wire less

The Eurocopter 225 Glycol system is a loss system. It is only designed to work for 30 minutes at Vy (approximately 70-80 knots) which equates to the minimum horsepower going through the MGB. It did not fail, it did its job and allowed G-REDW go get closer to land. It undoubtedly contributed to the successful ditching.

This is not correct.

From the AAIB SB S2/2012:

The crew of the helicopter carried out a controlled ditching following indications of a failure of the main gearbox (MGB) lubrication system and, subsequently, a warning indicating failure of the emergency lubrication system.

Brian Abraham

16th May 2012, 00:57

Be careful with SM, he is not SI presume the "S" refers to "smart". It's something I think most, if not all, here would agree upon.And well done to the crew for compliantly following the flight manualIt's a book of suggestions, not to be slavishly followed in all cases, which is where an aviators experience comes to the fore. Slavishly following manuals, SOPs etc have been the cause of past accidents. Being management with your head stuck where the sun don't shine you wouldn't be aware of that.

Tcabot113

16th May 2012, 00:58

Heli

One only needs to read the GE AAD summary reports to know that it is only a minor improvement and others need to realize it is not capable of real time results.

As to pilot alerts the reg agencies forbid it for very good reasons.

TC

SASless

16th May 2012, 01:17

B73....read the statement very carefully....it said "indications of a failure" which does not mean the system actually failed.

My impression upon reading the AAIB report was the Glycol system worked...but Cockpit indications were it had failed. HC and others discussed the fallibility of the sensors associated with the glycol system and noted their TBO was halved after routine Engineering protocols determined the problems with them indicating properly.

I am sure HC shall set me straight if I am off in this.

cyclic

16th May 2012, 07:33

I think the emergency lube becomes slightly irrevelant when you have an unsupported shaft loose in the gearbox. Metal was being made hence the chip caption. The only option here is to do what the Captain did. Emergency lube is for loss of oil, not for a catastrophic failure of a gearbox component. EC obviously thought that this would never happen otherwise you wouldn't put both pumps on the same shaft.

Nf stable

16th May 2012, 07:50

Nicely said Cyclic, that's the most sensible post I've read for a while...

TrisG

16th May 2012, 08:18

I work offshore. The "we" you refer to are the people who were present at the OIM's brief.
He was relaying information given to him directly from Bond via the operating company.
The chopper in question landed offshore (at our installation) on an earlier flight and reported some high vibration levels which were subsuquently relayed to the beach and the crew were informed they were within operating limits and it was safe to continue.

Thats all I know.

Fareastdriver

16th May 2012, 09:14

It amazes me how the shaft managed to break. Gearbox oil pressure, main and standbye, is not very high and I would not have thought that it would put any undue torque on the driveshaft. The early Pumas did not even bother with a pressure guage; they just had a light on the CWP. I presume they were standard gear pumps like 100,000s of car oil pumps which seem to go on for ever. I can see why EH thought it might never cause a problem.

Etouffee

16th May 2012, 14:57

HUMS in real time would not be a reality, near real time maybe and segmented data maybe but not true real time. You could have the system do some alerting to notify someone at the beach/ops center of a potential issue and may be able to do some spot or threshold monitoring but currently that would be about it.

A few other issues you would have to deal with and have been raised in other discussions is how much do you want someone from outside the aircraft making choices for those in it. Not only would you have to deal with a lot of decisions on what extent you want to go per your company guidelines you may also have to deal with government/operational area rule sets as well which may limit or prohibit this activity.

Then you have to deal with equipment. On a truck or piece of shore based equipment you have an unlimited amount of flexibility as to where you can place your antenna and the gear for the system and how it's wired up. With an aircraft you just can't do that. Not only do you have to get approval to add the gear, you may not have the proper real estate on the airframe to place it.

On top of that you have to judge satellite communication reliability. I would guess that most company's don't know what that is currently but I can tell you that at times it can be spotty and most days you will have at least 2 short periods of drop out of coverage (Iridium) . They are short but they will effect any and all data. In addition you can count on it that systems will loose connectivity and need to have power recycled and you will need a way to identify that the system is not sending data or good data and have the pilot intervention to try and correct the issue.

So a but off the main focus of the thread but some things to consider when talking about real time HUMS data.

ironchefflay

16th May 2012, 17:41

just a small point for etouffee.

The coastguard utilise sat comms as well as some of the O&G fleet in aberdeen, so they are used.

GS John

16th May 2012, 19:57

All the talk of real time HUMS totally depends on the system recognising that there is a problem. If the failure is a first ever, how do you know what the symptoms will be?

BabyGravy

16th May 2012, 20:29

If this a/c had "High Vibration" on an installation how could the beach possibly relay that it is within limits and to continue without seeing the a/c or checking the hums data ?

HeliComparator

16th May 2012, 21:24

Exactly, and that shows both the power and the danger of "a little knowledge" and Chinese whispers!

Or maybe they checked the pilots' teeth fillings, and finding them still intact, with headsets having not fallen off, declared the aircraft to be serviceable.

I do have some sympathy with the offshore guys - we scare them witless with the Safety videos (aka disaster movies) before each flight, and we feed them just enough information for them to be frightened. Sometimes I think it would be better if we behaved like British Airways etc and just stonewalled any requests for information following minor events such as the one cited.

HC

PlasticCabDriver

16th May 2012, 23:06

I think I'm with HC on this one, sometimes a little information is not always the best thing. The chances of the crew noticing and then reporting back to base the additional vibration associated with a shaft in the gearbox developing a crack (note not yet broken, just developing) over and above all the vast amount of other vibrations that a helicopter routinely produces just in normal operation are about 4/5ths of **** all. There may have been a vibration problem with this ac, but I would be gobsmacked if, in this case, it were to do with the shaft in question.

SASless

17th May 2012, 00:29

HC....most of the offshore workers understand we enjoy spending all that money they think we make....thus are not going to willingly, knowingly, and with malice a fore foot....do ourselves in before getting back to the beach.

We cannot all be suicidal.....can we?

We might take a duff machine but it will not be intentional.

Epiphany

17th May 2012, 05:02

Once upon a time I walked out to the aircraft wearing a Kamikaze headband which the pax thought quite funny. Of course that was in the days when people had a sense of humour and my actions were not recorded on mobile phones, displayed on Youtube, then the front page of The Sun and subsequently half the country were baying for my blood. I would, of course, be sacked the same day following interviews with the Police, Mi5, someone looking for publishing rights and a lawyer insisting that I sue the company for false dismissal.

Aviation used to be fun. You tell the young 'uns today and they just won't believe you.

TrisG

17th May 2012, 07:50

In all fairness I was only passing on info passed on by our OIM - The data could have been analysed back onshore and probably was.

Im trying to enter into a proactive discussion to find out some facts.

Assumption is the mother of all f**k ups. That one goes both ways the last time I checked.

For the record in the 12 years Ive worked offshore Ive not heard one bad remark about the pilots or the money they earn. Nobody cares what you earn. We just want to get home safe and sound just like you.

Being stuck out here can be frustrating at times when were fogged on or the weathers up etc, but I can assure you the vast majority of us appreciate the efforts the pilots and crews put in to get us to work and back again in on piece.

T

Colibri49

17th May 2012, 08:56

Questions for Helicomparator.

Why use welding at all to join gear wheels to shafts? That seems like an invitation for trouble.

Why not use a technique (I don't know the correct name; possibly shrink-fitting) whereby the two components are machined to a very tight interference fit, then the shaft gets chilled with liquid nitrogen, the gear wheel gets heated and after the two components are joined and once temperature normalises, the resulting joint is as good as machining the two components from one solid piece of metal?

From what I've been told, welding will always create some kind of stress raiser in metal, no matter what heat-stress-relieving process gets employed after welding.

If this technique is good enough for railway carriage wheels, it ought to be good enough for helicopter gearboxes.

HeliComparator

17th May 2012, 09:22

Colibri - I am flattered that you direct your question to me, but as a pilot, not a metallurgist, sorry but I don't have a clue! However I do understand that this component has always been welded together - the modification for the 225 over 332L is just to do with the treatments. As such the welded-together concept has proven itself over millions of flight hours.

gasax

17th May 2012, 09:27

The power consumption of turbine oil pumps is pretty low. My best guess would be less than 10hp for these engines. That leads to comparatively 'low quality' driveshaft arrangements. Remember that a number of cars use plastic water and oil pump drive assemblies due to those low power requirements.

Shrink fit shaft arrangments tend not to be preferred because their strength is highly dependent upon fabrication tolerances - hence the use of splines in the majority of high power applications.

In theory reasonable quality control should mean these sort of shafts are 'fit and forget'. But if it can do wrong, sooner or later I suppose it will and that seems to be what happened here.

The saving grace in this case was the 30 min emergency system and good decision making by the crew.

diginagain

17th May 2012, 10:20

My thanks must go to the Bristow S-92 crew who brought the Norway cab out for us yesterday. We often take you blokes for granted, don't we? Anyhoo, a question if I may? Could only see the RHS pilot, but noted you in your bonedome. Is this because of that 4R pulsing?

2papabravo

17th May 2012, 10:31

Might just be personal choice...they're allowed that over that side.

diginagain

17th May 2012, 10:48

Having worn one in a previous life, I can buy that. Apologies for the slight drift.

TiPwEiGhT

17th May 2012, 10:55

Helmets are optional in Bristow Norway, pilots choice, most of them choose to.

teej5536

17th May 2012, 11:01

Tris:

Do your best to keep a thick skin, we all get a little defensive and the trouble we aircrew have is the sense that few people out there, for some reason or another, have a gripe (whether within our own company or by customer etc) we rarely hear any thanks but often feel the hot breath of some unhappy soul down our necks. Forgive the chronic defensiveness especially as this sort of subject can lead to aircrew being perceived (incorrectly) as borderline suicidal apathetic nut jobs by people who become aggressively involved in distribution of misinformation (not accusing of such).

The point that is being challenged in your comment is the ability to send "data back to the beach", (apologies if that's a misquote) as there is no facility to do so other than picking up a phone and describing to an engineer what the heli is doing. The analysis of HUMS data is carried out on return to base when the card is removed from the aircraft and downloaded to a HUMS desktop station. Also, the ability to detect a vibration related to this particular failure through your back side is borderline impossible until shortly before the failure itself takes place. Any excessive, or abnormal vibration associated with the gearbox would most likely result in the aircraft being shutdown on the rig, or if in flight: a great deal of arse puckering and brow sweat. Leading to the expectation that this information being distributed by the OIM is misleading (not necessarily their intention) when done so in the context of the accident as there is not any known connection between it and this report of vibration.
More likely would be a blade out of track/balance or some other less critical issue.

Hope this helps.

Interesting heard yesterday: apparently ConocoPhillips are not flying pumas anywhere in the world just now, until the AAIB have concluded their investigation. Busy old time for the S92s in ABZ?

Bravo73

17th May 2012, 11:31

The saving grace in this case was the 30 min emergency system and good decision making by the crew.

Just for clarification, gasax, but the Em Lub system was not 'the saving grace'. cyclic sums it up best in his earlier post:

I think the emergency lube becomes slightly irrevelant when you have an unsupported shaft loose in the gearbox. Metal was being made hence the chip caption. The only option here is to do what the Captain did. Emergency lube is for loss of oil, not for a catastrophic failure of a gearbox component. EC obviously thought that this would never happen otherwise you wouldn't put both pumps on the same shaft.

industry insider

17th May 2012, 12:22

"This" failure couldn't happen in the S-92 as it does not use a single shaft to drive both pumps.

teej5536

17th May 2012, 12:37

Design consideration for a revised puma gearbox perhaps? Doubt it...

Etouffee

17th May 2012, 14:53

As they should ironchefflay as it is a great help.

I know from experience though that the failure rate of comms is a bit higher then most expect. Sat Comm calls don't go through the first time every time and they are not clear as a bell every time either.

Looking at the data side, and I do every day all day, you can have failures there as well which was really my point that real time monitoring would be difficult but not impossible if done in a manner that fit.

Brom

17th May 2012, 16:07

Not sure about the emlube 'not being the saving grace' in this incident, it certainly played a part.
Without doubt, this was a particularly nasty failure in the MGB and could, in itself, have led to a very different outcome.
No oil pumps = no oil pressure = no MGB lubrication. My point is that emlube does what it says on the label and provides limited lubrication (and some cooling) to the GB, without it we run the additional risk of an MGB seizure, and that would definitely have resulted in a very different outcome.

maxwelg2

17th May 2012, 19:45

FWIW the S92 had historical issues with vespel splines on its pumps and no EMlub system, just a useless bypass switch which does nothing unless you have a cooler leak. We're still waiting for the revised MRGB which will hopefully have increased durability, although with a phase 3 MRGB housing crack in Denmark recently we still appear to have some way to go wrt. QA/QC/design.

IMHO a long way to go in improving our current designs in several A/C types, kudos to the bus drivers for making the right decision in this case.

Safe flying

Max

PO dust devil

17th May 2012, 20:11

Late to join this one - congrats the crew for a great decision and defaulting to the safest action. Hope I get to work with people like you.

Also I guess the write off of the hull will marginally increase the value of every other 225 in service. So the companies should send the pilots a commission.

The oil companies should send them a bonus for not risking
a.potential loss of personnel by persisting with flight and
b. not crashing onto a platform helideck risking a billion dollar facility.

well done crew. fwiw.

DD

Colibri49

18th May 2012, 21:37

A dedication to the superb Bond pilots who carried out a flawless ditching on 10th May:

The fighter pilot's prayer: "Lord I pray for the eyes of an eagle, the heart of a lion, the agility of an antelope, the cunning of a fox and the balls of a helicopter pilot."

Grey Area

18th May 2012, 21:46

http://ad.easa.europa.eu/blob/easa_ad_2012_0087_E.pdf/EAD_2012-0087-E_1

The plot thickens......

cyclic

18th May 2012, 22:14

So, EC had identified the faulty shafts but now they're not so sure. We have gone from continuing to monitor, to ditching (perfectly acceptable to EC), to 6 hrs between downloads, to 4 hrs and back to 5 hrs to accommodate certain operators and now 3 hrs if you have a newish shaft. Presumably if the shaft has done more than 500 hrs it is likely to be ok - test flying phase complete. The incident was 8 days ago and the goalposts have moved again. Fill you with confidence?

SASless

18th May 2012, 22:17

Two Questions are begged....

Why 500 Hours?

Why not simply "REMOVE" all suspect shafts and return them to EC?

After all....we are not looking a vast number of these things in the fleet are we!

ironchefflay

18th May 2012, 22:20

thankfully not a big problem for aberdeen operators at the very least.

all are equiped with m'arms and all downloaded between flights. just got to look at a different parameter.

May not be good for length of flights tho.

cyclic

18th May 2012, 22:26

So you have the choice, the 5 hr 225 or the 3 hr 225, which one do you want to take offshore? Which one does your customer want you to use? I think it is a bigger problem than it first appears.

cyclic

18th May 2012, 22:36

Nothing, you are quite right, there is nothing that can be done.

iamthetroll

19th May 2012, 01:33

10 shafts per batch, so 9 remaining. None of which are in the UK, according to EC. G-REDW had the only one.

Daysleeper

19th May 2012, 06:39

So day VFR only presumably to make a ditching more survivable...but why is there not a sea state limit?

Grey Area

19th May 2012, 06:53

if you re read the AD you will see that it is applicable to all shafts with a serial number M0370 or greater and less than 500 hours so it appears that EASA are not convinced that this is a batch problem. I imagine the 3 hours limitation says something about their view on predicting this type of failure with HUMS.

I wonder how many 225s up in Aberdeen it will effect?

cyclic

19th May 2012, 08:05

Iron

It wasn't sarcasm, it is very easy to misinterpret the written word. I fully agree, there is nothing we can do. That doesn't make the situation any better though.

iamthetroll

19th May 2012, 08:45

Greyarea. EASA weren't the only sceptical ones...
L2s and (more so) S92s are probably about to take up the majority of longer flights.
My wonder is: with the speed at which the issues in EADs are typically rectified, how long will this drag on for?
Too long and it may well add a fair few nails in the coffin of any future development of the puma.

Colibri49

19th May 2012, 10:20

Honestly, I think that there are a lot of candidates for the "Conjecturing Olympics" contributing to this thread. There could be entrants for events like:

Jumping to conclusions
Running around in circles
Punching above your weight
Swimming out of your depth
Skating on thin ice
Shooting in the dark
Tossing things into the ring
Rocking the boat
Crossing swords
Leaps of logic.

It's all very entertaining to watch though.

bondu

19th May 2012, 10:25

Daysleeper,

So day VFR only presumably to make a ditching more survivable...but why is there not a sea state limit?

Good point!! There is of course a sea state limit - SS6, which is the "demonstrated" limit of the floatation kit. This equates to 6 metres.

These are weather reports received in Aberdeen from two offshore installations on 25 Oct 2011:

Time: 0708hrs
Wind: 124 at 53kts gusting 60kts
Cloud: 8/8 at 1500ft
Visibility: 11km
Temp: 11
Dew point: 8
QHH: 1002mb (hPa)
Significant wave ht: 6.5metres
Max wave ht: 10metres
Additional info: 'Within limits of DACON scoop - this is the only means of rescue available at this time'.

Time: 0925hrs
Wind: 130 at 50kts gusting 60kts
Cloud: Clear
Visibility: 8km
Temp: 11
Dew point: 7
QHH: 1003mb (hPa)
Significant wave ht: 7metres
Max wave ht: 11metres

Had Bond 88R ditched that morning, do you think the outcome would have been the same?

Obviously, you would not have expected anyone to be flying that morning, wouldn't you? Wrong! Only the pilots of one North Sea operator declined to fly that morning. The other two continued to fly as usual. As you can imagine, this caused problems for the company not flying, as the oil company clients started asking questions! Which lead to the management demanding answers from the pilots. Fortunately, all the pilots (around 20) refused to change their minds about not flying - only a decrease in sea states would have done that.

You would also expect that all three North Sea operators would have some form of instruction for operations with high sea states - wrong again! A comprehensive Flying Staff Instruction (FSI) was issued in October 2008, agreed by all three operators, but this was withdrawn after three days. Why, you may ask? Because the oil companies in Oil and Gas UK didn't like the restrictions it put on the operators when sea states increased! We, the pilots, were promised by our managements, that 'other guidelines' would be issued in due course. Three years later, in 2011, no such 'guidelines' existed. The only 'guidance' available was from BALPA and good old fashioned common sense - ie don't operate outside the aircraft's limitations!

So I'll ask you once again, what would have been the outcome of the Bond 88R ditching had it occured on 25 October 2011?

Stay safe everyone.

bondu

iamthetroll

19th May 2012, 10:29

How else are we arm chair experts to pass our time? It is a rumour network, which is tantamount to a casual blether by medium of text.

Personally I'd like to nominate myself for shooting in the dark. Which field will yours be? Heckling from the bleachers? ;)

SASless

19th May 2012, 13:31

Bondu,

There is risk to almost everything we do in life.

The Authorities have calculated the Risk factor of those kinds of failures that will put you into the oggin.

The Oil Companies and Operators have determined the trade off between Risk and Cost and have apparently decided the current mode of operation is worth the cost.

Their case is proved by the very fact that 88R did not happen in Sea States you describe.

The two Operators that flew were just as safe as the one that did not fly as it turned out.

As the chance of having to ditch is so insignificant....and the likelihood of having to do so in Sea States above the certification level of the Aircraft....why not operate over Sea States in excess of SS6, air temps at or below freezing, and water temps not much warmer?

If we write off a crew and a load of passengers now and then....they are paid for under the Cost-Benefit Analysis the Oil Company and Operator have done....are they not?

bondu

19th May 2012, 15:52

SASless,

You are absolutely correct, as usual! Just so long as the Cost-Benefit Analysis stays in the black, who really cares. I always wonder what the beancounters would decide if one of their own relatives was a regular passenger, or heaven forbid, if the beancounters actually had to fly themselves?

Just a silly question though: I wonder just how much the oil companies place on the loss of two pilots, up to 19 pax and of course an expensive EC225/S92/AW139 etc? Half a days profit: a full days profit? No doubt they will have it covered by some fancy insurance. Of course, their fancy expensive lawyers will argue that the decision rests with the helicopter operator not the oil company. And the operator will no doubt say that the pilots should have exercised their judgement and push any and all blame onto the crew.

Nothing changes!:ugh::ugh:

bondu

HueyDog

20th May 2012, 07:07

Bondu,

I suspect that the Oil Company's insurance will not be involved at all. They have a contract with the operator and since the operator retains operational control of the helicopter, only the insurance of the operator will be involved.

HeliComparator

20th May 2012, 11:20

Bondu

Remember, SS6 is not Limitation, it is only what the equipment has been certified to in a wave tank. The key issue is whether or not the heli will roll over, and this is not only related to wave height but also wavelength and in particularly whether the waves are breaking.

If the heli did roll over, the outcome might or might not have been worse.

Bearing in mind there is no such thing as Safe or Unsafe in aviation (merely shades of grey) it is surely down to probabilities. Probability of ditching in the first place is very low, probably of ditching in unsuitable sea conditions say 50 times less (ie let's say 7 days a year with high SS) so it is getting down to the levels of probability around which the fundamental design of the heli is based, eg the propensity of the rotor blades to remain attached etc.

HC

cyclic

20th May 2012, 11:57

HC

I don't know if is the case but isn't the S92 limited to SS6 in the Flight Manual as opposed to the certification?

212man

20th May 2012, 13:06

I don't know if is the case but isn't the S92 limited to SS6 in the Flight Manual as opposed to the certification?

No, it is not the case - there is nothing in the limitations section about sea state.

SASless

20th May 2012, 13:39

HC....if the aircraft rolls over with people inside....the outcome is definitely going to be worse than if it stays upright. There might not be fatalities...but the stress and exposure would cause harm to the occupants.

A controlled ditching....and loading of the rafts directly from the cabin beats hell out of the thing going upside down, cabin filling with water, occupants escaping from underwater, then having to enter the rafts (if at all possible) from the water.

Bondu's point about considering Sea State and Environmental conditions as a limitation to Offshore Flights bears consideration.

There is not a single scheduled Offshore Flight that must be flown when scheduled.....every single one of them could be delayed or cancelled till conditions improve.

When does "inconvenience" trump "Safety"......that is the question that needs to be argued.....not "probability"!

js0987

20th May 2012, 14:09

The question then becomes "who decides." The operators? The oil companies? The government?

Very doubtful the oil companies will - costs versus probabilities = costs win. Operators, unless they all get together and put their foot down - what's the probablity of that? - won't. As for the government regulating it, undoubtedly the first question would be - if we restrict helicopters from flying over let's say a sea state 6, what about commercial airliners? We all know what the answer to that question would be.

cyclic

20th May 2012, 14:17

212

Thanks. I had heard it somewhere, I don't know if it was related to the Cougar accident.

maxwelg2

20th May 2012, 15:37

Cyclic

Some good did come out of Cougar 491, one area was discussions wrt. the limitation on sea state, especially over here where we have a much higher number of annual sea state days > SS6 criteria in comparison to other offshore flight operational areas.

Although all our regular S92s have been upgraded to SS6, the decision on acceptable flying conditions is to my knowledge made by Cougar based on mutual agreement with the operators (see Q42 in the attached Q&A link below). There are different limits based on each operator/installation type. The common denominator is 6 metres, no one over here will officially fly regular operations in that and/or wind speeds > 55 knots. Visibility is our other big issue over here, we have a lot of fog days.

http://www.cbc.ca/news/pdf/nl-helicopter-safety-20090512.pdf

Bond 88R could indeed have been a much different story via multiple scenarios. Having not flown with Bond in many years I do not know what type of HUEBA is used if any, last I recall is the Shark rebreather but they may have moved on to the Airpocket Plus, either one I know from personal experience are IMHO inferior to the HUEBA, e.g. my last OPITO refresher was done in Malaysia last year where they make you do 5 HUET exercises, the last one being deploy Airpocket Plus underwater upside down, knock out window/door and egress. Add in cold water shock etc. and the statistics tell us that maybe only 50% of occupants will manage to egress an inverted helo.

Safe flying

Max

MightyGem

20th May 2012, 20:12

Hmm...probabilities. The probability of me having an engine failure in my EC135 during a flight are extremely remote(has there ever been one?). The probability of me having one during the few minutes during take off and landing are even less. The probability of me having one during the few seconds it takes to accelerate to single engine fly away speed during take off are infinitesimal.

However, I'm still required to fly the Cat A/Class 1 profiles.

As the probabilities are so small, need I bother?

HeliComparator

20th May 2012, 20:13

SAS- by outcome I mean of course long term injury, death etc. and whilst this obviously becomes more probable, it would by no means be a certainty bearing in mind the extensive training and safety gear.

You are of course right, no flights HAVE to be conducted. In fact helis are intrinsically dangerous and it would be far safer to keep them in the hangar. In fact sitting on an enormous pocket of pressurised and explosive oil and gas, whilst probing it with a long steel drill is even worse. Best we go back to horse power, though do mind those hooves, they are quite dangerous.

Or to put it another way, Oil and gas industry including transport is a calculated risk. The calculations of risk should be based on science and not the fear of seeing big waves underneath you.

HeliComparator

20th May 2012, 20:16

MG - I am inclined to agree. Aviation regulation is obsessed with engine failure training when it is not a significant cause of multi engine heli accidens. It is historical from when piston power was the order of the day, and the authorities have not moved on because they are using emotion rather than hard facts to decide what is important.

gasax

21st May 2012, 07:51

Helicomparator - you're right the assessment should be based upon the risks.

Unfortunately the risks associated with probing a high pressure reservoir, getting the stuff onboard, separating it and stuffing it down a pipe are on a well designed installation (there are a few) pretty close in round terms to the risks of getting to and from it for the people who work there.

For the pilots who fly them to and from the risks are actually significantly higher.....

For risks I'm talking about the individuals risk of death per annum, whilst undertaking their normal rotas.

For Mighty Gem - the chances of an engine failure during that critical period of flight are actually more of less equal to the rest of the entire flight (if it is under an hour). Big power changes are very likely to cause issues. Hence the need to fly profiles which offer a chance of recovery.

The major disappointment for me is that all of the 'newer' designs which are used offshore in the UK have had a variety of issues - which frankly should not have occured. From my personal perspective if you certify a helicopter on the basis of 10-9 failures per hour and it promptly fails then the certification should be pulled. For the 332 and 225 failures - I despair - designing reliable transmissions after all this time should not be so hard....

ShyTorque

21st May 2012, 08:27

For the 332 and 225 failures - I despair - designing reliable transmissions after all this time should not be so hard....

Surely, from the evidence already found, i.e. a bad batch of gearbox components, this would appear to be a production / quality control error, rather than a design error?

HeliComparator

21st May 2012, 10:01

Gasax - not sure you are right about the levels of risk far more people have died whilst offshore than whilst in transit by helicopter. But when someone falls off a rig, is asphyxiated etc it is just another industrial accident. Only when an installation turns into an inferno with associated good photo opportunities and multiple deaths does the level of public interest reach that occurring when a heli ditches and everyone is fine.

On the subject of design, I firmly believe that the certification system is mostly to blame. There are such huge hurdles to be overcome to achieve certification of new bits, that manufacturers prefer to limp on with old designs when they can. When they can't, rather than designing a new system from scratch, they will design a bolt-on patch to allow the deficiencies to be lived with.

Of course these great certification hurdles, once overcome, in no way guarantees a safe product as is routinely demonstrated. And don't get me started on the effectiveness of software certification - it is a joke!

Certification is nothing more than a block to progress and product improvement. Discuss!

Regarding your last para, if that were done there would be nothing left flying and it would be the rowing boat offshore for you!

HC

gasax

21st May 2012, 10:29

HC - this is partly how I earn a living - the numbers for helicopter transport are that bad....

One would have hoped that defect tolerant design codes would have lead to an improvement - but they have not - at least in the present incarnation. I'm not sure the certification inself is the real reason. For instance JAR approvals for a new engine are quite modest - but of course the certification process and approvals engineers can have a huge influence in terms of 'opinion engineering', drawing things out by insisting of often irrelevent justifications - and that leads to manufacturers doing everything possible to avoid the certification process. Hence the re-treading of earlier 'successful' designs with numerous mods.

Shytorque -- yes the information to date does suggest a QC issue - but underlying that are design decisions - this is a 'low duty' shaft with appropriate levels of design detailing. Titanium studs would be another. At the end of the day it all rolls up into an overall incident rate.

bondu

21st May 2012, 11:36

HC:

You are quite correct to point out that wave height alone is not sufficient. The wavelength and period, leading to the steepness of the waves are just as important, if not more so. However, such data is not measured offshore so cannot be transmitted to the crews before flight planning. This is a similar situation to the question of heave. As offshore pilots we all knew that actual heave was not the real problem – it was/is heave rate. How many years did it take to finally get heave rate data introduced? How many years will it take for the ‘authorities’ to act on accurate sea state reporting?

Probability – what is the probability of having to ditch? 1 in 10 to power 7? 10 to 8? 10 to 9? Since 1989, there have been 5 separate incidents of G-reg helicopters ditching around the North Sea:
Apr 1989 G-BGKJ Bo105 Oil pollution flt near Scacsta 1 passenger
Jan 1995 G-TIGK AS332L Crew change flt near Brae A 16 pax
Nov 2006 G-JSAR AS332L2 Crew change? Dutch sector 13 pax
Feb 2009 G-REDU EC225 Crew change flt near ETAP 16 pax
May 2012 G-REDW EC225 Crew change flt near Aberdeen 12 pax

5 incidents in 23 years, all different reasons, but with the same end result – 60 pax in the sea. How does that stand up against the level of ‘probability’? Based on Aberdeen Airport’s latest figures, there are approx helicopter 500,000 passengers per year. That would amount to around 11.5 million in 23 years. 60 pax out of 11,500,000 – that’s about 1 in 200,000. I wonder how they feel about being just a ‘slim probability’. How do the oil workers perceive that probability? Let us not forget that these guys are just going to work. If they are late, so what? And perception is the key word here. Why are there no Chinooks flying offshore oil support today? Should the oil workers, your passengers, lose faith in the EC225 or the basic survivability of ditching, what then?

So, let’s look at what the ‘authorities’ have to say. A gentleman by the name of David Andrew Howson of the CAA SRG, issued a paper titled “RESEARCH INITIATIVES FOR IMPROVING THE SAFETY OF OFFSHORE HELICOPTER OPERATIONS” – link www.ihst.org/Portals/54/Partners/India/3_Howson.doc (http://www.ihst.org/Portals/54/Partners/India/3_Howson.doc)

Page 4 makes interesting reading.

Further suggested reading is HOSS/WP-99/8.5, (link http://www.jaa.nl/secured/Operations/Member%20Area%20OPS%20Helicopters/Meetings/Meeting%20Documents/2004%20HSC%20Meeting%20Docs/0%20HSST%202004-3%20Closing%20Papers/HOSS%20Ditching%20Survival.pdf) extracts below:

“Taken on their own, the FAR/JAR would require the designer to select a reasonably severe wave condition for the area in which he expects the helicopter to operate and to demonstrate that the probability of a capsize has been minimised. FAA and JAA however, have adopted an interpretation (AC29-2A para 337(a)(3)) which states that Sea State 4 is considered to satisfy the reasonably probable requirement.”

“Although sea keeping qualities vary from one helicopter type to another, most types currently in use will capsize in sea states in the range 4 to 5 and above. A recent study of wave climates along a representative selection of main helicopter routes in the northern North Sea and West of Shetland (regarded in JAR-OPS 3 as a Hostile environment), indicates that Sea State 4 will be exceeded on 26-36% of occasions over the whole year (Ref. 1). During the winter period between December-February, this increases to between 51-65%. If the certification requirement was raised to Sea State 6, the risk of exceedence would fall to a maximum of approximately 3% over the whole year and 3-7% in the winter months.”

The history of North Sea oil support helicopters has been one of continuing safety improvements. In the early days, neither pilots nor passenger had survival suits or even lifejackets. Offshore survival training didn’t exist. No HUMS systems, single engine helicopters, single pilot operations, DECCA moving maps. I could go on, but you should get my drift. The industry must continue to improve safety and the perception of safety.

bondu
Edited to correct figures - thanks John

bondu

21st May 2012, 11:39

Just received this:

EASA AD 2012-0087-E: Eurocopter EC225 Helicopters : Main Rotor Drive - Main Gear Box Bevel Gear Vertical Shaft - Inspection / Limitation | Publications | About the CAA (http://www.caa.co.uk/application.aspx?catid=33&pagetype=65&appid=11&mode=detail&id=5025)

bondu

John Eacott

21st May 2012, 11:58

5 incidents in 23 years, all different reasons, but with the same end result – 60 pax in the sea. How does that stand up against the level of ‘probability’? Based on Aberdeen Airport’s latest figures, there are approx helicopter 500,000 passengers per year. That would amount to around 11.5 million in 23 years. 60 pax out of 11,500,000 – that’s about 1 in 1,000,000.

Try 1:196,000

In the early days, neither pilots nor passenger had survival suits or even lifejackets. Offshore survival training didn’t exist. No HUMS systems, single engine helicopters, single pilot operations, DECCA moving maps.

We had lifejackets, and fought hard for immersion suits which were finally issued in 1978. Most pilots were ex RN and had Dunker training but civilian HUET was a future dream.
All NS offshore helicopters were twins, DECCA was as good as you could expect and generally did a good job if you had the DANAC version, SP ops for rig shuttles but two pilot for crew changes.
HUMS was up there with pagers, mobile phones and the internet. We didn't have them because they hadn't been invented :p

SASless

21st May 2012, 12:11

During the winter period between December-February, this increases to between 51-65%. If the certification requirement was raised to Sea State 6, the risk of exceedence would fall to a maximum of approximately 3% over the whole year and 3-7% in the winter months.”

Winter is the time of the year when SAR issues grow....short days, cold air, rough seas, hypothermia, cold shock.

Perhaps there is merit to requiring Sea State 6 flotation systems. It will still come down to a determination of cost/benefit....which unfortunately has to be measured in human lives at some point.

If we use the logic of some....comparing the offshore helicopter industry to the World's Airline industry....should we not first agree we should have the same reliability numbers that the Airlines maintain?

When we do....have the same reliability, fully instrumented approaches, lead in lighting, radar surveillance, stable landing areas....and all the rest....then perhaps that is a fair comparison....but not until then.

Even then....would we revert to wearing our normal casual attire to/from the rigs and platforms?

SASless

21st May 2012, 12:27

John me old Son....

I distinctly remember being single pilot, two channel SAS, Mk 19 Decca (pre TANS), and flogging between Teeside and the Ekofisk in a S-58T, wearing a Musk Ox Rubber/Canvas Survival suit and Nomex flight suit.

When we started the Ninian Shuttle....as the field was being built....we were two Pilot crews.

I drew the line at night Single Pilot....Ma's favorite Son preferred having two feet solidly ashore once the Sun went down. It did not make me very popular with some of the Office Pilots but I am here today all fat and sassy.

We lost one 212 and almost lost a 58T doing single pilot night flights offshore. One disappeared and the other had to be rebuilt after going inverted (or some very unusual attitude in that the cabin attendant commented about standing on the overhead of the cabin).

What I am saying....is Bondu is closer to the truth than you are. Your experience was on the Brent Shuttle as I recall.

Bristow had been operating Whirlwinds, then Wessex offshore long before the S-58T and 212's showed up.

Also...my memory of the Mk 19 Decca is this.....I want to meet and shake the hand of any Man that ever did the Decca approach to Sumburgh, Single Pilot, at Night, IMC, in Snow, in a S58T or Wessex. That is the approach that required both a Map and Key change. I personally do not believe it is possible to multi-task to that degree! One would have to have the arms of an Octopus and the mental dexterity of a couple of Einsteins to get that done and remain greasy side up.

There has been a lot of improvement on the North Sea.....but there is no reason to stop improving yet.

bondu

21st May 2012, 12:41

John,

Apologies on the figures!
As for single pilot ops, I was still doing crew changes from Unst out to the Ninians single pilot in 1992. Yes, most of the flying was inter rig shuttles, but it was common the fly up to three pax in and out of Unst if the loads were too high for the S61s.

As for DECCA DANAC, yes it was the best at the time. But that's precisely my point - things have improved. New technology, new ways of operating etc. That's what should happen, isn't it? We have to keep pushing for better kit, better understanding of the environmental conditions we operate in.

bondu

bondu

21st May 2012, 12:47

SASless,

I spent three years operating from Ninian North - all single pilot, day/night IFR. With a DECCA moving map that 'jumped' a lane in heavy rain - just when you needed it most! Those were the days!! Tell the young uns today and they'll never believe you!

You are absolutely correct - this is not the time to stop pushing for improvements!

bondu

SASless

21st May 2012, 13:39

What fun this kit was to operate in anything that had "static" like rain or snow! It worked great on nine knot ships surrounded by water!

http://www.jproc.ca/hyperbolic/decca_rx_ind_mk08rx.jpg

HeliComparator

21st May 2012, 14:46

gasax, sorry but if you are saying it is incorrect that many fewer people have died in transit by helicopter to/from offshore North Sea, than have died whilst working on North Sea oil/gas installations, then I find it very hard to believe and please provide the figures and the source.

If you want to factor it by the number of hours of exposure, then possibly you are right because they spend a long time offshore, and a short time in the helicopter. However in terms of the risk encountered when doing a job offshore, I would consider that to be distorting the figures because it is surely the overall probability of coming to grief during an offshore rotation that is the real-world issue.

If the same number of people had onshore jobs, how many more or less would have died on the roads driving to work every day, than did in a helicopter?

HC

Bravo73

21st May 2012, 15:10

gasax

21st May 2012, 15:40

HC - read the safety case on one of those installation you fly to - the information should be presented in there.

On a modern well designed platform the transportation risks to an offshore worker per year will be approximately 40% of the total.

I've not calculated the individual risks to pilots, but I know from doing that for offshore workers with routine shuttling and sleeping offshore that on a 2:2 rota anything over 120 shuttles per year puts them into the 'unacceptable' risk levels of 1 x 10-3 per annum. So if you are a pilot flying 900 hrs per year and sleeping onshore your risk levels will be significantly higher than that.

Bondu has it - the timing of these flights is discretionary - getting onto them is not. The flight risks from what the oil operators would call scheduled flights, have the risk numbers associated with flying fixed wing with a bankrupt airline from the former Soviet block - not a choice many people would make if informed of the numbers.

I am a realist and fully understand that attaining fixed wing levels of risk is not possible. What I dispair of is the current helicopter accident rate - both due to design and operation.

Yes people die, at work, at play at all sorts of things. But when there is no good reason for it apart from vested interests eventually something has to break.

Fareastdriver

21st May 2012, 16:03

Apr 1989 G-BGKJ Bo105 Oil pollution flt near Scacsta 1 passenger
Jan 1995 G-TIGK AS332L Crew change flt near Brae A 16 pax
Nov 2006 G-JSAR AS332L2 Crew change? Dutch sector 13 pax
Feb 2009 G-REDU EC225 Crew change flt near ETAP 16 pax
May 2012 G-REDW EC225 Crew change flt near Aberdeen 12 pax

You have taken the accidents and then used them as a comparison with Aberdeen's passenger figures. Two of them did not depart from Aberdeen so you can ignore them; Other wise you will have to include all the other heliports around the North Sea.

Bravo73

21st May 2012, 18:03

Bondu has it - the timing of these flights is discretionary - getting onto them is not.

A small point of order - getting on these flights is discretionary. Nobody is forcing people to get on these flights, or even to work offshore. There is always the option of going by boat.

gasax

21st May 2012, 19:21

No Bravo - there is no option of going by boat. If there were and it made any sense do you suppose the oil operatosr would hire those nice cheap helicopters?

Crew boat hire - maybe £2k per day can carry 100 persons, 332 what £5k per hour can carry 19?

In places where it can work - like offshore W.Africa and the Middle East, the majority of the workforce are transported by boat. Try it in the N.Sea. The one example I am aware of in the Central N.Sea where it was tried had such a lousy dispatch rate the money on building the facilities was considered wasted by the operator......

Fareastdriver - the industry risk figures are just that industry - either UKCS, UKCS plus Norway or OGP and split by region (although not helped by the FAA not categorising ditching as an accident....!). There are good summaries of all this data available via google. But the crux of it is that offshore helicopters would be shutdown in W.Europe if they were scheduled airlines - they are that far short in terms of deaths per flight/hour/sector when compared with scheduled fixed wing. So accepting that mechanically they will always lag due to the complication of the machines it still leaves a lot to make up - and they are many posters here who are trying to do that - arguing about off the cuff numbers just muddies the water.

Droopystop

21st May 2012, 19:30

Gasax,

What units are you using in your calculations? Accidents per flying hour, minute, day, per sector, per flight? Is 10^-3 that you calculate validated by the actual accident rate?

SASless

21st May 2012, 19:37

Out of those numbers we have to deduct those that were not survivable at all....like the Bond aircraft that shucked its rotor head.....if we are talking about Sea State/Ditching issues.

The Chinook crash would tilt the numbers quite a bit too....as there were survivor(s) on that one.

Coming up with accurate stats is going to be awfully hard because of the record keeping or lack of it. Getting the raw data and then putting it into a useable data base will be a days work for sure.

mazdadriver

21st May 2012, 20:18

I'm really very nervous about the stats and list of accidents being posted as 'hard' facts today. With all respect to Gasax, if this is how he makes his living I have to wonder about the effects of the confusing and incomplete data that might be sourced from him.

For example, where is the 'VX' S-76 fatal accident? I struggle to believe that there are not also other incidents and accidents from elsewhere around the North Sea that are missing. On the other hand, as noticed by Fareastdriver, using Gasax's list and ABZ pax numbers does not produce a very smart, consistent, analysis, as JSAR is in the list. Anyone would think every offshore-related sector must originate in Aberdeen! If his data is meant to be North Sea-wdie, there are many very active offshore bases in NL, DE, NO, BE, DK, example, and he should remember that many flights have a significant number of offshore stops, with a number of passengers being carried each day but not seeing an airfield at all.

Stats have their uses, but only if they are thorough, reliable, and unambiguous. Stats that have such serious flaws as seen today should be removed immediately, rather than remaining here to further mislead the majority of readers who have no way to know the nature of the errors.

Perhaps someone from Shell Aircraft could post some of their offshore stats, or a link to them, as I have a high degree of confidence in their studies. Last I heard from them, offshore helicopter transport, measured globally, had a similar level of safety as flying on a commuter turboprop. If we must be stopped, then so must a large number of fixed-wing scheduled and charter operations! Good news for the railways, at least:-)

If Shell's database was filtered to exclude the less regulated states, it is possible the safety level would be significantly higher than for turboprops, and I'm definitely curious to know what would result if looking exclusively at the entire North Sea area, and then again at the UK sector only.

lowfat

21st May 2012, 20:59

Don't forget.....

"There are three kinds of lies: lies, damned lies, and statistics."

Now we have statisticians joining the accountants crucifying the industry.....

Shell Management

21st May 2012, 21:03

Naturally the oil and gas industry has carefully monitored the performance of the licenced helicopter operators. :)

Full impartial details of there performance can be found here:
Selected Publication - Oil & Gas UK (http://www.oilandgasuk.co.uk/publications/viewpub.cfm?frmPubID=240)

Of course not all oil companies take an equal interest in safety. :(

SASless

21st May 2012, 21:27

If Shell's database was filtered to exclude the less regulated states,

Whoa Big Fella.....you mean Shell operates to different standards World Wide?

What about the fact it is one big Oil Company who bangs its chest proclaiming itself to be The Standard Setter of the Industry?

If Shell was Obama....and you were a good loyal Democrat you would find yourself setting up campaign signs in Shemya Alaska or very small island near by after making that comment!

Shell Management

21st May 2012, 21:33

Shell does itself operate to uniformly high Shell Aircraft standards globally.

Shell also monitors ALL accidents and the OP simply suggested that data was filtered for proper statistical comparison. That sort of statistical validity is all rather complex and a little bit beyond the average aviater.

mazdadriver

21st May 2012, 21:46

SASless, thanks for the response, but to clarify I wasn't trying to infer Shell Aircraft's database is only filled with stats regarding their own contractors. They have a very comprehensive set of industry-wide (not just Shell) data, and analyse it objectively. Contrary to one of today's posts, doing so is not a job that might take a day, they've spent months doing so over many years.

Say what you like about Shell, whether in terms of their ability to maintain set standards, or how they deal with their contractors, but Shell Aircraft have proven to be the leading 'setter' of standards, with the best of intentions. People need to understand a little more about the structure of the Shell organisation before criticising them. SAI have limited authority to force Shell E&P, around the world, to follow their standards.

Bravo73

21st May 2012, 21:52

No Bravo - there is no option of going by boat. If there were and it made any sense do you suppose the oil operatosr would hire those nice cheap helicopters?

There is always the option to go by boat. Supply vessels go out every day.

But it is quicker and more convenient to go by helicopter. Nobody is 'forced' to work offshore. And nobody is 'forced' to travel by helicopter.

air-bender

21st May 2012, 22:00

Most offshore workers I've met are none too happy whenever they end up having to "go by boat"

SASless

21st May 2012, 22:06

The boat ride wasn't so bad.....but the basket ride by crane up onto the rig was sporty!

maxwelg2

22nd May 2012, 00:31

There is always the option to go by boat. Supply vessels go out every day.

Bravo73, for information there are sea state and visibility limitations for vessel transfers just the same as for helo transfer. Over here in the Grand Banks it's about 3 metres and the crane operator has to be able to see the PAX when transferring them in a Frog 3 at a time and/or a Billy Pugh.

In most cases the green light is given for helo transfer long before vessel transfer is an option. Only over here where we can end up with nearly two weeks without flying due to fog do we resort to vessel transfer on a somewhat regular basis. The only other time that happened was post-491 when the S92s were all grounded.

I don't know how many supply vessels you have these days in the North Sea, but when I worked over there about 9 years ago some installations only got a boat once or twice a week.

Sea states change quickly, so after 12-15 hours on a boat getting out into the field, you can sometimes end up "boomeranging", not a pleasant experience. That is why operators and PAX prefer the helo transfer option. However, all personnel transfer has to be made as safe as is reasonably practicable. Flying a/c with suspect QA/QC issues in a specific number of high priority components, i.e. bevel gear shaft required for MRGB lub oil system, does not IMHO meet this requirement.

Everything we do has inherent risk incorporated, how we choose to minimize that is up to us.

Safe flying

Max

mazdadriver

22nd May 2012, 07:13

For boat transfers, have a search for "smit kamara" and "offshore access system".

The Smit Kamara has been used routinely in the North Sea in recent years, but is still subject to sea-state limitations. Boat transfers do not have to result in getting in to a cage suspended from a crane!

EDIT: The Kamara has been mostly utilised to provide an alternative to shuttling by helicopter. Instead of shuttling from a central hub platform, the personnel stay on the Kamara overnight, but it moves around fields dropping teams on several unmanned installations in the morning, collecting them agauin in the evening. As a result, it is a shuttling vessel, not just an accommodation unit staying at one location.

gasax

22nd May 2012, 08:58

You're all correct in terms of the statistics. The OGP data from outside Northern Europe is shall we say, less than rigourous? Similarly the GoM and once you get into the 'stans simply not worth looking at.

However in the N.Sea the data is reasonably robust. Given the tendency of aircraft to fail at take off and landing, the usual way to slice the data is to use the number of sectors for that part of the data and the number of hours for the 'cruise' part of the flight. Typically we use the post Chinook data, as that single accident dominantes the data set otherwise.

Ditching - which sort of brings us back on thread is not explicitly used - I'll have to have a look and see how 'easy' it is to extract it. Bondu's numbers are probably a little high but not a million miles out. Add in the likelihood of the weather being poor and I tend to side with the BALPA view of life.

As for the Kamara - it is a single vessel, intended for use as a flotel - not as transport. Its weather limitations would make its use outside of the southern sector not just non-economic but not viable. Essentially in the N.Sea personnel movements depend upon helicopters - there are no viable alternatives.

HeliComparator

22nd May 2012, 10:18

Given the tendency of aircraft to fail at take off and landing, the usual way to slice the data is to use the number of sectors for that part of the data and the number of hours for the 'cruise' part of the flight

But actually that isn't really true, is it? Recent fatal accidents - 2 out of 3 (L2 and S76) were effectively cruise accidents. Only the 365 could be considered to be associated with takeoff/landing. All these little incorrect assumptions can creep in to skew the stats.

On the subject of non-aviation offshore deaths I would not trust oil company data. Their aim will be to minimise offshore deaths that "count" and so will be using all tricks to do so. They have a major vested interest so how could they be trusted to produce unbiased statistics?

gasax

22nd May 2012, 11:45

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.

maxwelg2

22nd May 2012, 13:33

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

mazdadriver

22nd May 2012, 14:18

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.

batboy1970

22nd May 2012, 22:59

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.

ironchefflay

23rd May 2012, 00:04

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.

Careful with that! you may be on the ground a long time! i was told on a Puma Course the Rotor head mast takes 2 years to Age Harden. i think the Epicyclic does also. there was a real shortage of gearbox part a few years back with our O/H place having a backlog waiting for parts.

maxwelg2

23rd May 2012, 00:29

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

SASless

23rd May 2012, 02:22

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?

gasax

23rd May 2012, 07:55

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.....

HeliComparator

23rd May 2012, 10:26

Then it gets into service and much like software we all become beta testers.

Unfortunately this is true, always has been true and probably always will be! It is not realistic to expect a manufacturer to flight test their products over the tens of thousands of flight hours likely to be encountered in an airframe's life, and over the wide range of roles. And even if they did, as soon as some tiny element is changed, that invalidates all the testing (weakest link in the chain etc) and the manufacturer would have to start again. Nothing would ever fly commercially, or if it did it would be astronomically expensive.

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

HeliComparator

16th Jun 2012, 08:47

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?