Sikorsky S-76 down in the North Sea (Threads merged) [Archive]

fat pax

16th Jul 2002, 21:14

FROM BBC NEWS

Seven people are missing after a helicopter crashed into North Sea off the Norfolk coast.
The civilian Super Puma helicopter went down 25 miles north-east of Great Yarmouth on Tuesday night, said the Ministry of Defence.

A total of five people have reportedly been found in the sea.

A massive search and rescue operation is continuing for the other people on board.

An MoD spokesman said: "An RAF Sea King from Wattisham in Suffolk was scrambled at 7.50pm as part of the rescue operation, which is ongoing."

He said coastguards have a vessel looking for casualties.

Search vessels

A spokeswoman for Great Yarmouth coastguards said the helicopter was bringing workers from a North Sea gas field when it ditched.

The helicopter is believed to be owned by the firm Bristow.

The spokeswoman said a rescue helicopter from a military base in Wattisham, Suffolk was in the area along with the Cromer Lifeboat and other vessels.

Rescued casualties had been taken to the Santa Fe Monarch oil rig, the MoD said.

A spokesman for the East Anglia Ambulance NHS Trust in Norfolk said they are liaising with the coastguards.

"We have not received any patients yet but have senior officers at strategic points throughout the north of the county.

"We have crews on standby and will await news from the coastguard as to where survivors will be brought."

The spokesman said the James Paget Hospital, in Gorleston, near Great Yarmouth, was on standby to receive patients.

http://news.bbc.co.uk/hi/english/uk/newsid_2132000/2132618.stm

As in all circumstances such as these, my thoughts are with those involved and their families.

Stupendous Man

16th Jul 2002, 21:26

BBC and ITV news say a S76 but their websites say Super Puma!?!?!?

TipCap

16th Jul 2002, 21:28

To my knowledge, Bristow doesn't have any Super Pumas out of Norwich and the numbers concerned certainly seem to indicate a S76

Stupendous Man

16th Jul 2002, 21:40

Unfortunately Sky News is now saying 5 killed and 6 missing.

Thoughts go out to all involved.

magbreak

16th Jul 2002, 21:43

Sorry chaps a bit of misinformation in my last post. I've spoken with some one 'close' to the incident and it was definatley a Bristow S76 (VX).

Capn Notarious

16th Jul 2002, 21:47

Wouldnt it be an advancement in reporting : if the media restrained themselves and, did not use words like crashed.
The truth is not known: all is speculation and upsettiing; it might have been a controlled event.
How do make them change and put a sympathetic style into news casting?
Because selling news papers is not the main criteria.

Stupendous Man

16th Jul 2002, 21:57

http://www.sky.com/skynews/home

Five Dead In Helicopter Crash
Five people are dead and six more are missing after a helicopter bound for a gas field crashed in the North Sea.

The helicopter, owned by Shell Oil, ditched at around 8.20pm on Tuesday night, around 25 miles off the coast near Great Yarmouth, according to the Royal Navy.

Also http://www.itv.com/news/Britain1825700.html

SASless

16th Jul 2002, 23:51

Capt Notarious.....five dead...rest missing.....weather benign....light winds...."controlled" ??? Twin engine helicopter operating within CAT A specs....two very experienced , well trained pilots.....not going to speculate here at all. Lets wait for the information to come out.

Definitely holdin my breath until the crew's names are released.....may have to stop over in the UK enroute to work in the Middle East, to go pay my respects to the families....this is getting to be too common an occurrence.

magbreak

17th Jul 2002, 01:40

From the Telegraph:

Eleven British gas rig workers were thought to have been killed last night after a support helicopter crashed into the North Sea.

The Sikorsky S76 helicopter, operated by Bristow Helicopters, ditched 25 miles north east of Great Yarmouth at around 8pm. The helicopter was carrying two crew members and nine workers from the Clipper natural gas platform, operated by Shell.

A coastguard spokesman said: "We have recovered six bodies and are looking for five others. We are not expecting to find survivors."

He added: "There were two crew on board and nine passengers. We received a mayday call and within minutes the fast rescue boats from the rig were on scene. But the impact had been so severe that the occupants we found had suffered appalling injuries and had not survived."

The cause of the crash was not clear last night.

RAF Kinloss, in northern Scotland, which was helping to co-ordinate the rescue, said weather conditions were good.

The coastguard spokesman added: "Normally, if a helicopter manages to make a controlled landing into the water it will float long enough for the passengers and crew to escape and probably survive.

"But it seems that this Bristow helicopter hit the water at a high speed judging by the amount of damage it sustained and the injuries the victims suffered."

The accident comes 10 years after 11 oil workers were killed when a Super Puma helicopter went down in the North Sea. In that accident, in March 1992, the helicopter crashed in gales and driving snow.

zaplead

17th Jul 2002, 08:34

My deepest sympathy goes out to all touched by this incident.....

TheFlyingDJ

17th Jul 2002, 08:53

Sad sad news again. Heard that all S76's are grounded, but does that mean worldwide?
Friend of mine is a freelance offshore worker as a diver and sat those S76's before. Safety training is hard and i am wodering what the hell went wrong.
Very anxious to read the rapport about it before all kinds of speculation occurs.

Thoughts go to family's and collegue's.

Heliport

17th Jul 2002, 09:08

A very sad day, and a time to remember the very real dangers which North Sea pilots face.
God rest the souls of those who died.
Our thoughts and prayers are with them and with their families.

Heliport
Moderator

ShyTorque

17th Jul 2002, 09:11

:( Very sad news to me, especially as one flying this type of aircraft for a living.

My thoughts go to all those involved, families, friends, all at Bristows.

Heliport

17th Jul 2002, 10:06

Five people have now been confirmed dead and a massive SAR operation is continuing for a further six who had been on board.

The S76 was on a routine trip from Norwich airport to rigs in the North Sea. It left Norwich at 1900 BST on Tuesday with nine workers and two crew on board, flew to the Clipper platform, and then continued to the Santa Fe Monarch drilling rig.
It was on this leg of the journey that the helicopter crashed, two miles from the rig.
Staff on the Santa Fe Monarch rig made the call to the coastguard saying the helicopter had gone down.

http://news.bbc.co.uk/media/images/38140000/gif/_38140240_crash_north_sea2_150.gif

An RAF Sea King from Wattisham in Suffolk was scrambled and five bodies were recovered from the water within two hours. The Sea King was stood down in the early hours of Wednesday morning and the search was continued by coastguards and rig support vessels and lifeboats that had been in the area. They are concentrating on a five-mile radius of sea close to the rig although no wreckage from the helicopter has been spotted.

The Duty Rescue Controller at RAF Kinloss where the operation was co-ordinated, said the search continued on Wednesday under "near perfect conditions". He said: "We still have not found survivors and we fear that this points to a worst case scenario."
The two crew on board worked for Bristow, three of the passengers were Shell staff, three worked for engineering firm Amec and two for Amec subcontractors. The remaining passenger was from Oil Field Medical Services.

Heliport

17th Jul 2002, 10:08

FlyingDJ
Let's get this in proportion.
Bristow has temporarily suspended all their helicopter flights to and from the rigs in the southern North Sea.

The Sikorsky S76 has an excellent safety record.

TheFlyingDJ

17th Jul 2002, 10:27

Thanks mod!..
It was somehow what unclear to me.

Heliport

17th Jul 2002, 11:06

I've been asked to post a photograph of an S-76 for the benefit of Ppruners who are not familiar with various helicopter types.

http://www.sikorsky.com/Images/SAC_Sikorsky_Aircraft_Corporation/US-en/S76C_Utility1.jpg

The photograph is of an Offshore/Utility model.

In its more familiar 'executive' version, the Sikorsky S-76 is generally regarded as the 'Rolls Royce' of the corporate helicopter world. It is used, for example, by the UK Royal Flight.

Heliport
Moderator

Blue Rotor Ronin

17th Jul 2002, 12:13

What a terrible loss, this has hit hard. There's no point ranting at the papers, they will always speculate to accumulate, regardless of the effect it has on anything other than pennies for papers. My deepest sympathies to the crew and passengers loved ones.

Wayne Jenkins

17th Jul 2002, 12:31

I know I speak for all my collegues downunder..........

This accident is not only tragic for the individuals affected, including all the loved ones and families, but for all involved in the Offshore and Helicopter Industry.

The S76 is indeed a mature and proven helicopter platform for such a demanding industry, and I am sure the authorities and company involved will establish the relevant causes in the fullness of time.

A sad day indeed for all.

Pirate

17th Jul 2002, 13:13

A bad week for UK helicopters. The previous day the Portland Coastguard helo crashed and burned, although happily all the crew got out.

baldspot

17th Jul 2002, 13:33

Comments below from RAF Sea King crew who arrived on scene shortly after accident. I appreciate there are those who think it crass to question the causes of such a tragedy without waiting months for the AAIB findings, however, I think it is only natural that we seek to discover answers and information from the professionals who share this forum. I also have to say I do not believe to call such an incident a "crash" is itself an exaggeration when by then we had five confirmed dead and many missing.
Just a personal point, but one thankfully this forum allows me to make.

Flight Lieutenant Paul Hopson - the pilot of the Sea King Mark 3A scrambled to
search for survivors - said today: "At this stage we cannot say what happened
but all the indications are of a major mechanical failure.

"As far as we were aware, there was no May Day call and certainly no
emergency beacons were activated, which suggest it happened very quickly."

Co-pilot Flight Lieutenant Steve Murkin said it was unlikely to have been a
controlled ditching and the crew would have had little time to escape.

He said: "As more and more information came, it looked like it must have been
something quite catastrophic. It was not a controlled ditching as we had hoped.

"It must have been something major because it sank quite quickly and nobody
got out.

"If it is a controlled ditching, as soon as the helicopter hits the water,
big flotation bags are inflated but there were none visible, so we do not know
if they were activated."

He added that the crew, including passengers, would have had survival and
escape training and would have been wearing specialist gear, enabling them to
survive in the water for hours.

In ordinary clothes, a person would be dead within an hour, he said.

The helicopter was scrambled at 7.50pm from Wattisham Airfield and arrived at
the crash scene, some 30 miles north east of Great Yarmouth, at about 8.30pm
yesterday.

On arrival, the crew saw a patch of oil and small debris covering an area just
200 yards across.

Boats which had arrived within seven minutes had already recovered five bodies
out of the 11 people on board.

Flt Lt Murkins said the visibility was good and the water was calm so if there
had been any survivors they would have been spotted easily.

"It was perfect conditions for searching. We could see everything on the
surface and it was quite evident there was nobody on the surface to rescue. The
biggest thing we saw was a seat cushion.

"Because there is always an outside chance of survivors, you keep looking.
But within an hour it was pretty clear we were not looking for survivors in this
case anyway.

"Given the speed at which the rescue agencies were on the scene, it is likely
some of the bodies will be found in the wreckage."

Following an intensive search along with 18 boats, the helicopter crew left
just before midnight.

An investigation will be carried out by the Air Accident Investigation Board,
part of the Civil Aviation Authority, said Flt Lt Hopson.

The wreckage will probably be recovered by specialist salvage units and form
part of the investigation to find out exactly what happened, he said.

slot misser

17th Jul 2002, 14:35

Witnesses on the rigs state there was an explosion seen prior to the a/c ditching.

These workers have just arrived at NWI so will no doubt be questioned by th AAIB.

God bless those who lost their lives and god bless their families.

TqNrT4NgGreenlightCWP

17th Jul 2002, 14:55

Anybody know who the crew were yet? e-mail to me if you do not wish to post publicly yet, please. I have an old mate who was last heard of flying that type from that base. Discretion promised.

Heliport

17th Jul 2002, 16:00

I've been asked for guidance whether it would be appropriate to make comments concerning Bristow engineering on this thread. I've suggested it would be inappropriate and any such comments should be made on a different thread - subject to the usual rules.

Rotorheads is essentially a professional forum for the helicopter industry worldwide. With so many of our members flying the S-76 and/or having experience operating in the North Sea, it is inevitable that there will be informed comments as more information becomes available. I see no problem with that.

Unless I receive any messages of disagreement with either of these two suggestions, I'll assume they reflect what members wish. It's your forum.

Heliport
Moderator

Special 25

17th Jul 2002, 19:01

For those interested, here is a photo of the aircraft in question. It was the one and only that Bristow had painted in the proposed new livery.

http://209.196.171.35/images/newliverys76.jpg

My best wishes to all.

quidam

17th Jul 2002, 19:16

We all stumble when one of 'us' falls..........

Rotorbike

18th Jul 2002, 04:11

Part of the story from The Independent this morning:

A specialist salvage vessel carrying divers and remote-controlled submarines will start work today at the scene of Tuesday night's tragedy to search for the bodies of six victims believed to have remained trapped in the Sikorsky S-76, sitting in 30 metres of water about 45 miles off the Norfolk coast.

Clive Mather, chairman of Shell UK, said the firm had suspended all flying operations in the southern North Sea until the cause of the tragedy was pinpointed.

One of the victims was named as Angus MacAthur, 38, of the Isle of Lewis, Ross-shire. He left behind a wife and two young sons. Norfolk police said the names of the remaining dead would not be released until tomorrow. They include six men from Norfolk, two from Teesside and one each from Lancashire and Suffolk.

My thoughts and prayers for those affected by this accident.

Autorotate

18th Jul 2002, 07:24

Without being bashed here, could someone advise if the weather conditions played a part in the possible cause. Just wondering.

Autorotate.

Hoverman

18th Jul 2002, 07:25

An awful tragedy. May they rest in peace. It always hits home when fellow pilots in our small sector lose their lives at work.

The rentamouth 'experts' wheeled out on when ever there's a fatal crash are a pain. But as its highly likley there was a catastrophic mechanical failure of some sort and the 76 is a well-proven type with a good safety record, the "mystified by why it was not predicted by standard maintenance checks" Rotorbike quotes does seem like a fair question to ask.

Rotorbike

18th Jul 2002, 07:40

Autorotate

Quote from an earlier post:

RAF Kinloss, in northern Scotland, which was helping to co-ordinate the rescue, said weather conditions were good.

Special 25

18th Jul 2002, 09:55

In further response to the above - Weather conditions were excellent. I beautiful clear evening with a flat calm sea and very light winds. I think we can pretty much rule out weather as a factor although it would be pointless to speculate beyond that.

SASless

18th Jul 2002, 11:35

Had contact with Bristow this morning....names of crew not to be released publically yet pending completion of recovery operations. We continue to wait to hear who the crew was.

HeloTeacher

18th Jul 2002, 12:32

Just a note, "excellent" weather for one thing may not be so "excellent" for another.

Glassy water and light and variable winds (one way of interpreting the above) are by no means excellent conditions. We, thus far, know nothing.

semirigid rotor

18th Jul 2002, 13:04

Heloteacher,

I agree - calm or light winds with a flat sea are not ideal flight conditions.

Once again the media feast for sensational reporting has led to speculation bordering on hysteria. Whatever the cause (and I'm sceptical about major mechanical failure), let us all spare a thought for those who are directly or indirectly involved. There, but for the grace of god, go all of us.

JAFCon

18th Jul 2002, 17:19

My thoghts for all those that have lost loved ones in this accident, but also lets not forget that the Engineer who signed the A/C Servicable and all those that worked on it are now going through all sorts of hell and wondering if perhaps they missed something while inspecting and servicing the Aircraft, even if the've done everything right, the worry is still there.

Once again my thought's to all involved particually the Engineers

:( :( :( :( :(

Hoverman

18th Jul 2002, 17:39

semirigid rotor
The pilot of the Sea King who got to the scene half an hour after the accident described the visibility as good. SAR pilots in that area spend most of their time flying over the sea. He wasn't some passing tourist desibing visibility. He also thought, rightly or wrongly, that the little evidence available pointed to a catastrophic mechanical failure.
Please don't take offence, but I can't understand how you can say we shouldn't discuss possible causes AND then be the first person on this thread to suggest possible pilot error, throwing in you're "sceptical about major mechanical failure"!
We all know it's just theory until we know more from the AAIB investigation but I doubt if there's many crewrooms where pilots haven't discussed this tragedy, their theories, experience offshore flying, the S76 etc. That's what happened in ours.
Did you follow the threads after the PaveHawk crash? No accident report yet, but the quality of discussion was outstanding and some of the posts were nothing short of brilliant.
I don't think anyone needs reminding to "spare a thought for those directly or indirectly involved." Just look at all the messages that have been posted. We're a small community and we all know 'There but for the grace of God' we could all go.
'Talking' to each other on Rotorheads is just like talking to each other in the crewroom. It's just unrealistic to expect pilots not to exchange ideas, give opinions. It's natural, and it's not disrespectful of the dead.

Cuddles

18th Jul 2002, 19:31

The names of the crew have been released:-

From BBC news online

The pilot has been named as Captain Phillip Mark Wake, 42, from the Norwich area, and his co-pilot as First Officer Phillip Dearden, 32, of Norwich.

http://news.bbc.co.uk/hi/english/uk/england/newsid_2136000/2136765.stm

What-ho Squiffy!

18th Jul 2002, 21:44

Right on, hoverman. I agree.

helmet fire

18th Jul 2002, 22:44

My sincere condolences to the families. May those on board rest in peace.

Back on page 3 there was a mention of the possibility that the remaining personnel on the rig spotted an explosion on the aircraft. Has this been at all verified? Was the crash site close to the rig? Within sight? Is this why rescue teams were so quickly notified despite the absence of a mayday?

Also, was the accident on the way back from the rig, or the way too it?

What-ho Squiffy!

18th Jul 2002, 22:52

From what I saw on the news, some of the rig crew saw/heard an explosion. Apparently within a couple of miles of the rig, and I think on the way to it. I am sure I will be corrected if I am off the mark.

helmet fire

19th Jul 2002, 01:45

I have re read the thread and appologise to Heliport - he has already posted the answer to my second Q. He quotes the BBC who say that the aircraft went from the airfield to the Clipper rig, then departed Clipper for Sana Fe Monarch. The accident occurred approx 2 miles from Santa Fe Monarch - according to the BBC. Apparently from all the quotes thus far, the accident was a catastrophic event that prevented any semblance of a controlled ditching.

As echoed from the posts above, with such a well run, experienced operation, flying such a safe and proven airframe, such accidents are extremely rare.

Do they have CVRs and FDRs fitted to these airframes?

Edited to delete questions that may be interpreted as undue speculation.

GLSNightPilot

19th Jul 2002, 03:27

I see no way the baggage doors could cause it - they're hinged in the front, latched in the rear, & a lose door would tend to stay closed, not blow off. The cowlings on top aren't likely, either. I don't recall any accidents relating to them, but my memory isn't perfect.

Nick Lappos

19th Jul 2002, 03:46

In all deference to our curiosity and deep interest, nothing can be gained by pure speculation. There are fine professionals working this as we "speak" and we will know what there is in just a few days.

Hang in there. Someone posted, after the Air Force Mt. Hood accident, that we will end up remembering the finest speculation, and the real cause, from which we could learn, will be forgotten.

papaindia55 flaps

19th Jul 2002, 11:46

helmet fire

Yes they do have CVFDR fitted to all North Sea machines.

magbreak

19th Jul 2002, 14:54

Some more news from the BBC:

http://news.bbc.co.uk/hi/english/uk/england/newsid_2138000/2138899.stm

Heliport

19th Jul 2002, 18:55

Extracts from latest Statements by Shell
North Sea Helicopter Crash Update
"On behalf of the joint accident investigation team, Shell U.K. Exploration and Production can advise that the specialist survey vessels continued the search for the missing people and the wreckage of the helicopter throughout the night. The sonar contacts on the sea bed identified by the Geosearcher vessel were evaluated using an ROV (Remotely Operated Vehicle) deployed from the Kommander Subsea.

At approximately 08.00 this morning wreckage was located together with three bodies.
The location of this wreckage was close to the most probable crash site based on witness statements and analysis of radar data. Plans are currently being developed to position the DSV Mayo over the site to allow divers to recover the bodies when tidal and current conditions allow safe diving to take place.
At this stage we are not sure how much of the helicopter has been found and therefore the search for the remaining three missing persons and wreckage continues.

The names of those whose bodies have been recovered and identified are:

Stuart Coggon (45), from Middlesbrough.
Draughtsman with Amec Offshore Development.

Philip George Stone, (53), from Norwich.
Senior Engineer with Amec Offshore Development.

Kevin John Taylor, (50), from Norwich.
Technician with Amec Offshore Development.

Denis Andrew Kelleher, (40), from Lancashire.
Medic with Oilfield Medical Services.

Angus MacArthur, (38), from Dingwall.
Surveyor with Hi-Cad Technical.

The other six on board were:

Geoffrey Bispham (51), from Norfolk.
Operations Supervisor with Shell Expro.

David Christopher Graves, (33), from Suffolk.
Operations Technician with Shell Expro.

Douglas Paul Learwood, (40), from Middlesbrough.
Instrument Technician with Shell Expro.

Paul Leo Francis, (48), from Norfolk.
Technician with Industrial Controls.

Phillip Mark Wake, (42), from Norwich.
Captain with Bristow Helicopters Ltd.

Phillip James Dearden, (32), from Norwich.
First Officer with Bristow helicopters Ltd.

Let us hope and pray that the bodies in the helicopter will be recovered and identified soon, and the missing three found, so that their families will be relieved of the additional anguish they must be suffering because of the uncertainty they face at present.

Heliport
Moderator

semirigid rotor

19th Jul 2002, 22:00

Nick, well said

Hoverman, please read my post again, I never said aircrew eror was to blame. By the media all jumping on the mechanical failure theory, the implication is an engineering error. My thoughts are not only with the family of those who have lost someone in this tragedy, but also the engineers who must be beside themselves with worry.

jacobsen

19th Jul 2002, 22:59

Good way of thinking!

offshoreigor

19th Jul 2002, 23:51

Just a question for those who know.

Are the BHL 76's equipped with the 'Air Deployable Rafts and Door Jettison System' and is there any way that system could deploy uncommanded, say if the door-pin was not completely seated? Secondly, I thought the North Sea machines only had HUMS and not a HUMS/FDR mix is this correct?

Finally, my deepest condolences to the families and friends of the crews and passengers.

:( OffshoreIgor :(

Woolf

20th Jul 2002, 09:46

As far as I know all offshore helicopters here have FDR. CVR and HUMS.

400 Hertz

20th Jul 2002, 12:15

All Bristow aircraft have HUMS fitted, designed originally by Bristows and Plessey and some others.

This system, called IHUMS, has combined CVR and FDR and HUMS in the installation, with the HUMS information on a data card, as well as some of it on the data recorder.

offshoreigor

20th Jul 2002, 12:24

Woolf, 400.

I'm aware that BHL machines are IHUMS equipped as one of our former Lloyd machines is so equipped, but we have a seperate FDR in addition to the DPAU. I'm wondering if straight IHUMS is a self contained unit on BHL machines or independant but intergrated like ours.

It will be interesting none the less when they recover the FDR/CVR for analysis. I only say this because many 76 operators worldwide wait for the initial investigation.

OffshoreIgor

Autorotate

21st Jul 2002, 05:27

Not sure if this was asked previously in this long thread but what sort of altitudes do the helos travel to and from the rigs. I would have thought that if they were at higher altitudes they might have had the chance to get away a mayday call but according to what I have read they didnt even get the chance to do that.

Autorotate.

400 Hertz

21st Jul 2002, 11:38

The HUMS acquisitions are carried out by one processor in the DAPU, there is another separate processor for FDAU (FDR) data gathering. The DAPU has no crash-proof memory.

The FDAU data (and some HUMS data) is stored on a standard CVFDR (voice and data) using a tape loop. It is this unit that holds the information that the AAIB will investigate.

magbreak

21st Jul 2002, 12:50

Autorotate what sort of altitudes do the helos travel to and from the rigs.

On the sector in question the transit would proably have been around 1500ft. Having said that if they were as suggested 1.5 - 2 miles from the destination rig they would have been much lower ready for the landing.

Red Wine

21st Jul 2002, 14:21

Heliport or anyone:.......

Has there been any worthwhile and official update on the accident?

News in Australia has slowed to nearly zero.

Most of the major Australian Oil Companies I understand have ceased operations with the S76 pending some statement from the UK.

Heliport

21st Jul 2002, 21:49

Red Wine
I've not seen anything 'official' since I posted the update last Friday.
I'm surprised at what you say about the Australian operators. Is that rumour confirmed?

Red Wine

21st Jul 2002, 23:57

Heliport.....

Just spoke to my colleague who works those machines.......they are firmly on the ground.

wde

22nd Jul 2002, 01:15

Canadian Helicopters Ltd in Canada operating nearly a dozen S76A's sent a priority message to all their bases in Canada on Thursday, mandating that the base engineering staff re-do a number or previously completed ASB's including the Rotor brake, main mast NDT, and T/R gearbox. I can emphasize that the motivation for this action was ONLY to ensure that these ASB's were completed properly and thoroughly. The due date for completion in July 22 at midnight save the NDT (FPI) on the main mast which has a re-do date of early August. Meanwhile, we continue to fly the aircraft for EMS work in Ontario.

magbreak

22nd Jul 2002, 09:01

The world wide fleet was never grounded. As an operator flying the B model we have heard nothing from Sikorsky at all. We are therefore still flying. I understand from a friend that the B models are still flying on the North Sea from Holland.

From my understanding of the situation Shell requested that the Bristow machines didn't fly in the Southern North Sea (English or Dutch side). I don't know whether that extends to Shell worldwide.

flyer43

22nd Jul 2002, 11:11

Red Wine

The newspapers over here are pretty quiet on the accident. However, the BBC Website is keeping reasonably up to date. The following link gives their latest, together with links on the right-hand-side to previous related articles.

In response to another users comment - S76's have definitely not been grounded. However, as a precautionary measure, some clients requested to discontinue operations on all variants pending some further news.

Heliport

22nd Jul 2002, 16:27

For our members who don't have easy access to UK news reports:

Five more bodies have been found, bringing the total to 10.
The search for the last remaining victim is continuing using the survey vessel, the diving support vessel and an ROV (remotely operated vessel).

A large amount of aircraft wreckage has now been recovered, including the Flight Recorder which has already been sent to the AAIB for analysis.

The rest of the wreckage will be recovered to the shore and sent to the AAIB.

http://news.bbc.co.uk/media/images/38141000/gif/_38141097_crash_north_sea5_300.gif

flyer43

22nd Jul 2002, 16:33

Oops. Forgot to give the URL of the BBC news site in my last posting

http://news.bbc.co.uk/hi/english/uk/england/newsid_2142000/2142385.stm

LowNSlow

23rd Jul 2002, 05:42

Our S-76 is grounded leaving us with a Bell 214 to service 2 rigs. It's because Bristows is a partner with a local Kazakh company as I understand the situation.

vertalop

24th Jul 2002, 06:11

LowNSlow

I think you will find that the S76 has not been grounded by any aviation authority, but by the operator as a safety precaution.

I believe that if you were to look in the hangar you will find that there are two Bell 212 helicopters (not one 412), configured to a very high safety spec, including IHUMS (CV/FDR), external liferaft. etc etc. These should be more than enough to service several rigs.

S76Heavy

24th Jul 2002, 07:12

Heard about it when deprived of my computer, hence the late reply. I feel gutted about it. But what puzzles me is that the A/C type has not been grounded by any authority. Unless one is absolutely positive that it is a one-off event (like being hit by a meteorite or a missile), how can anybody be sure that it won't happen again? Who is responsible for grounding a type?

Remember, whatever happened came about so quickly that there was not even a Mayday call. How can one justify continuous operation without even a clue as to what happened?:confused:

Flying Lawyer

24th Jul 2002, 08:07

"How can one justify continuous operation without even a clue as to what happened?"

On the contrary, how could it possibly be justifiable to ground an aircraft type with a well-proven safety record "without even a clue" about the cause of the accident? That would be a complete over-reaction.

Airliners sometimes crash without a 'Mayday' call. That doesn't mean the type is grounded until "one is absolutely positive that it is a one-off event (like being hit by a meteorite or a missile).

The Flight Recorder has already been recovered to the AAIB for analysis. If there was any reason to do so, the AAIB will would recommend that the CAA grounds the type pending further investigation. It would be up to the aviation authorities of other countries to decide whether to follow.

It is a sad fact that aeroplanes and helicopters crash from time to time. Grounding all other aircraft of that type pending an investigation would be silly.

S76Heavy

24th Jul 2002, 08:30

Flying Lawyer, I respectfully disagree with your views. As a pilot, I make damn sure that I plan the flight to be as safely as possible, covering as many variables that I can think of. Now it appears that there is a variable that is unknown, yet fatal..it killed in mere seconds.
I personally don't see how one can justify NOT grounding AC until they have been thoroughly inspected for possible failures.
Perhaps they have been checked already, as I mentioned I have had limited acces to hard info after a computer problem, depending on newspapers instead :rolleyes:
but should not the CAA have grounded the type on Tuesday and make some sort of drive train check ( I suspect that's where the cause will be found as it was a swift and catastrophic failure) mandatory before commencing flight operations?

And yes, it has affected me personally, perhaps that makes me biased

flyer43

24th Jul 2002, 09:17

S76 Heavy

"should not the CAA have grounded the type on Tuesday and make some sort of drive train check ( I suspect that's where the cause will be found as it was a swift and catastrophic failure) mandatory before commencing flight operations?"

It would be too easy to ground any flying machine following an accident and then implement some form of inspection on "selected" components.
Would you have been happy to resume flying after an inspection of the part(s) of the drive train? What about inspecting cowlings, doors, emergency windows, main and tail rotor blades, gearbox mountings etc. etc. etc. Failure of any one of these items could ultimately cause a catastrophic crash!! (Departing cowlings and doors could impact with rotor blades etc)
Where would you draw the line without any real evidence to work on?
Nothing from the initial reports would suggest that this accident indicates a generic problem with the S76. However, some operators and clients have demonstrated prudence by temporarily suspending S76 operations.

The AAIB now has everything at Farnborough. They have no doubt been working flat out to establish initial findings and will surely make recommendations in the very near future.
Let's not jump to hasty conclusions and fire off an unnecessary panic wave.

vibe

24th Jul 2002, 09:34

I understand a press release is out today, ref main blade spar failure on VX.

S76Heavy

24th Jul 2002, 10:03

Indeed, where DO you draw the line? I'm a pilot, not an engineer. But I want it beyond a reasonable doubt that my machine is safe to fly. And when in doubt, I chicken out. It's valid for weather, crew and for the machine.

I'm a bit confused about the issue of when to ground a type, but if it's a main blade spar, it seems generic enough for me.

Without casting undue critisism on authorities and people, I'd like to learn more about the mechanisms of the grounding of A/C and mandatory inspections. I remember mandatory rotor mast inspections every x hours just a few years back, because of a non-fatal accident. So what's the rule?

Perhaps Nick Lappos can comment on this particular case as a Sikorsky man?

flyer43

24th Jul 2002, 10:14

S76Heavy

"I'm a bit confused about the issue of when to ground a type, but if it's a main blade spar, it seems generic enough for me."

Now you are talking with hindsight. Your original statement referred to grounding the S76 when absolutely nothing was known about the possible cause of the accident.

Let's see what the press release says and hope that common sense will prevail thereafter.

I'm a pilot as well and would also like to know that I can confidently expect to be home after work each day!! Provided that suitable rectification and/or control measures are put in place by the right people, I would be happy to fly in any S76 again.

HeliEng

24th Jul 2002, 10:30

Deleted due to my own damed stupidity!!!!!

Red Wine

24th Jul 2002, 10:52

Is the Main Rotor Spa statement confirmed???.....or rumor???

S76Heavy

24th Jul 2002, 11:11

Flyer43,
"talking with the benefit of hindsight" You are missing my point. The point is that BECAUSE the cause was still unknown, people were talking unknown riscs in operating the A/C when it could very well have been a problem common to more S76s but just happened to rear its ugly head on VX. I was taught to assume the worst and cater for that in order not to get caught out.

I'm still not convinced that the type should not have been grounded until proven safe simply for commercial reasons. There are lots of reasons for not flying that are happily accepted because the riscs are obvious, e.g. icing, fog etc. On those occasions the clients will have to make different arrangements, so they could have made them in this case as well.

Again, I stress the fact that I am not bashing anyone, I just want to learn from this discussion. If we learn from this tragedy we may be able to prevent another.

And I DO intend to fly it as soon as it's cleared.

flyer43

24th Jul 2002, 11:50

S76Heavy

Thanks for that. I wasn't getting at you, just trying to suggest other ways of looking at things.

As far as I understand it, most decent operators who continued flying the S76 since the accident instigated rigorous inspections of major rotating parts prior to continuing flying. However, as stated before, just how much do you need to check to ensure an aircraft type is safe to continue flying, unless you actually know the cause of any accidents. Maybe they were right, maybe not. At least they did put some controls in place, if only for mitigations sake......

S76Heavy

24th Jul 2002, 12:40

Flyer43,
I did appreciate your comments, I just thought that you might have misunderstood mine.

We as a RW community should learn all the lessons from this tragedy and I feel there is a need to define what actions are to be taken after an accident and on what grounds.
By your taking part in the discussion perhaps something better may evolve, so thanks for the input.

So how do other pilots feel about the need for grounding their type after an initially unexplained accident?

leading edge

24th Jul 2002, 13:20

I don't agree with grounding unless a very clear reason for doing so can be established.

If a type is grounded, and then nothing conclusive is found, what justification can there be for ungrounding?

This terrible accident will prove (I believe) to be one of these "millions to one" chances. It is always a chain of events and circumstances which lead to an accident, break the chain and it doesn't happen.

The S76 has accumulated many hours of safe operation and it is unlikely that whatever "failure" caused this accident is a problem generic to the whole S76 fleet.

LE

magbreak

24th Jul 2002, 15:20

From the BBC:

Wednesday, 24 July, 2002, 15:10 GMT 16:10 UK
Rotor blade blamed for crash

A broken rotor blade was the most likely cause of a fatal helicopter crash in the North Sea.
Eleven men died when the Sikorsky S-76 crashed off the coast of Norfolk last Tuesday.

Air accident investigators say evidence from the wreckage suggests that one of the main rotor blades broke off during the flight between offshore rigs.

Ten bodies have been recovered, while the search for the remaining missing person was called off on Tuesday.

More soon.

magbreak

24th Jul 2002, 15:57

Bit more news. The BBC are saying that investigators are looking into a lightning strike in 1999 as a possible cause of weakening the rotor blade.

Grenadetosser

24th Jul 2002, 19:56

This isn't the first time a UK registered S76 has lost a blade in flight. Did not a Bristows machine crash onland somewhere near Peterhead some years back after loosing a blade in flight?

S76Heavy

24th Jul 2002, 20:50

I believe that was a spindle failure, not a blade failure as such.

wde

24th Jul 2002, 21:25

Anyone have the BBC link re possible cause of the S76 crash?

wde

24th Jul 2002, 21:35

Found it!!

http://news.bbc.co.uk/2/hi/uk_news/england/2149597.stm

Red Wine

24th Jul 2002, 22:26

If the BBC is an "Official" source, then the cause of this accident seems to be a detached blade in flight.

Firstly, I am relieved that it seems no engineer or the flightcrew will have to wear the responsiblitity.......[for once].

However a blade just does'nt detach without a cause.......someone or some system will have to explain their actions as the investigation unfolds.

"On condition" blades do "crack" from time to time..[I personally know of two in Oz]......but none involving the spar.

It will be interesting to see what the "Igor" team do now!!

Having a lot of time and respect for this aircraft and its systems.......I have always felt uneasy about increasing the Nr from 100% to 107% with the same drive train........same basic A model components with extra stress.

Not saying this is a direct cause......just a concern that has been lurking in the back of my mind since the A+ and A++ became a reality.......

PANews

24th Jul 2002, 22:59

There was a media report [BBC radio this week] that confirmed the blade failure 'theory' and added that the AAIB were looking at a possible link between an instance of lightning strike damage suffered by the lost airframe and the failure.

I guess that forming a conclusive link will take a while.

Nigel Osborn

25th Jul 2002, 01:09

A blade breaking off makes a lot of sense and explains why the crew had no time to make a radio call or do anything that could have possibly saved them.

Broken spindles caused the first 2 crashes about 24 years ago. The first in South America with 14 killed and the second a Bristow machine doing a NDB approach at Longside with 4 killed. That problem was fixed, so at least it's a new problem. Still incredibly tragic for all involved.

soggyboxers

25th Jul 2002, 07:55

About 2 years ago Aero Contractors Nigeria (Schreiner) had a large portion of the trailing edge detach from the inboard section of a main rotor blade of an S76B in flight. The crew only noticed a small increase in vibration at the time, but when they shut down after landing on a drill ship they discovered a large section missing and only the main spar there. I believe that it was due to a manufacturing defect of a batch of blades, and all blades from that batch were grounded until repair teams were sent out to apply a strengthening patch to them.

magbreak

25th Jul 2002, 09:24

Sikorsky have put out an ASB (Alert Service Bulletin) that blades which have been involved in lightning strikes should be removed before the next flight.

The AAIB have stated that there is no evidence at this stage to link the lightning strike, and the spar failure, but it is one of the variables under 'active consideration'.

Crepello

25th Jul 2002, 10:17

The AAIB preliminary statement in full:

"The Air Accident Investigation Branch of the Department for Transport has recovered more than 90% of the structure of the Sikorsky S-76A which crashed into the North Sea near the 'Santa Fe Monarch' offshore installation. The remains of the helicopter were recovered by divers working from the 'Diving Support Vessel 'Mayo'. The main debris field was approximately 180 metres long, 30 metres wide and some 40 metres below the sea surface.

The wreckage was transferred from the 'Mayo' to a smaller vessel on Saturday evening and brought ashore at Great Yarmouth during the morning of Sunday 21 July. It was then transferred by road to the AAIB's facility near Aldershot, Hampshire where the vital components were examined by investigators from the AAIB, the National Transportation Safety Board (NTSB) of the USA, the Federal Aviation Authority (FAA) of the USA, the aircraft manufacturer and the operator. In the same time scale, the combined flight data and cockpit voice recorder data were analysed by AAIB staff.

The flight and acoustic data show no signs of any significant abnormality until some minutes after the helicopter had left the 'Clipper' platform for the 10 minute flight to the 'Monarch' platform. During this short flight, the pilots discussed a small increase in vibration but this increase appears to be so slight as to give them no cause for concern. A few minutes later a catastrophic event occurred during the early stages of the helicopter's approach to land on the Monarch platform. The helicopter was in level flight at approximately 400 feet height and at a speed of some 100 knots. The data recorder ceased operating at this event and the eye witness evidence is still being collated and analysed to determine the final flight path. The accident was not survivable.

Amongst the wreckage were two items of major significance. Firstly, three of the main rotor blades exhibited only superficial damage whereas the fourth was fractured at a position approximately six feet from the blade root. The missing blade section was not recovered from the main debris field and the team are now confident that it lies elsewhere. The second significant clue was the condition of the main rotor gearbox. The casing had fractured and there was visible evidence that the gearbox together with the rotor head had broken away from the fuselage mountings.

The fractured blade was taken to a specialist metallurgical facility where the fracture surface was cleaned and prepared for metallurgical analysis. Preliminary results were inconclusive but on Tuesday, evidence of fatigue was found that enabled the investigation team to conclude that the blade fracture had initiated the catastrophic event. The gearbox had separated from its mountings due to the severe imbalance created by the separated blade section.

At this stage, there are a number of variables that are being evaluated to determine the likely origin of the fatigue. One variable may be related to a lightning strike suffered by the subject blade in 1999 but there are other variables under active consideration.

Following the lightning strike, the blade was returned to the manufacturer for evaluation before it was returned to service. Currently the investigation team is gathering more information about the history of this blade. At this stage, there is no evidence to link the lightning strike to the fatigue failure, however, this is one of the variables still under active consideration.

At 1600 hrs on Tuesday 23rd July the FAA and the United Kingdom's CAA were made aware of these findings. The FAA is the regulatory body which issued the original type certificate for the American built helicopter; the CAA is the regulatory body which issues airworthiness certificates for aircraft registered in the United Kingdom. Both regulatory bodies are now considering what safety action might be appropriate.

At this stage of the investigation, there is no evidence of any flight crew or line maintenance malpractice. The investigation team is now focussed on the reasons for the blade fracture, particularly the origin of the fatigue. This information may take some time to establish but it will be crucial information required by the aircraft manufacturer and the regulatory bodies in deciding the most appropriate safety action.

Any future statements issued by or on behalf of the AAIB will be through the Department for Transport's Press Office."

hobie

25th Jul 2002, 18:25

as background info could someone tell me a bit about the construction of the Blade in question, materials, dimensions etc ...... how much would a replacement blade be valued at ....... how sophisticated is the Vibration monitoring and reporting system/guidance to the crew?

Lu Zuckerman

25th Jul 2002, 23:18

To: Cyclic Hotline

What you say about spindle failures may be totally correct.
......................................
......................................
............................................
Now maybe I got it wrong .............................
I really do not know because I have no drawings or pictures relative to the construction of the S-76 rotorhead. :confused:

Lu
I've deleted your earlier post, and edited this one.
I'm also :confused: - that you could possibly think it appropriate to make such serious allegations. When challenged, it turns out you haven't got a shred of evidence to support your allegations.
Not only is it irresponsible, but it damages your own credibility as a contributor to discussions.
Please think before you hit the 'submit' button.

Heliport
Moderator

Cyclic Hotline

26th Jul 2002, 00:09

Thanks.

I have deleted my previous post to ensure that this subject matter is removed.

Just hoping to keep the thread and facts straight.

I personally feel that it is very important to ensure that anything that we discuss as fact, is indeed just that.

My sincere condolences to the families and colleagues affected by this tragic accident.

Lu Zuckerman

26th Jul 2002, 01:13

To: Heliport

I made the statements about the blade failures based on the facts, as I knew them. These facts were published in Aviation Week and Space Technology and were also told to me by one of the trial lawyers involved in the litigation that followed the accidents. If these two sources did not repeat the facts either truthfully or correctly then my information is incorrect and I will admit that fact if in fact I am proven wrong.

[Edited:
* Inviting people to "ask Nick" questions in the present circumstances unfair. Nick cannot possibly be expected to answer questions on this thread.
* Claiming that because somebody hasn't answered a question to your satisfaction means they haven't got an answer, or the answer would be damaging to their company is silly. Rotorheads is the leading helicopter website, but it is not an official investigation.]

I would strongly suggest that you have Flying Lawyer who knows Nick to ask those questions etc
See my comments above.

If you have followed my various posts I have never offered my sympathy to the survivors of those individuals of the accidents discussed on these forums. It pains me deeply when people are killed in any type of aircraft accident however I do my damnedest to keep that from happening. My profile reads: Keeping crew and passengers safe. That says it all. If I have to use these forums to make people aware of problems that might manifest themselves then I will do that provided I am not censored. :)

Cyclic Hotline

26th Jul 2002, 01:48

I'm not trying to start a war here, so please let's drop the matter.

Any action taken by the moderator of this forum, was at my request. The "facts" in discussion are simply untrue. I know, because like everyone else operating S-76's we dealt with the issue when it arose (a long, long time ago).

With all respect Lu, I am not questioning your credentials, motivation or credibility. I am simply ensuring that any technical discussion be limited to the actual events, causes, findings and remedies. The facts that I am disputing are the experience I acquired whilst dealing directly with these original occurences a long time ago. So facts? Well my facts I guess!

The previous failures related to main rotor spindles. At no time were the blades implicated. There have been other blade issues, but unrelated to a failure of this type.

It is entirely inappropriate that any employee of Sikorsky (especially of the stature of the very identifiable poster here) would make any comment at this stage of ANY investigation, or be requested to respond by any of us here. Although immediate cause and mitigation may be defined, the completion of the investigation is a long way away and it is quite unreasonable to consider that anyone from Sikorsky would comment in any other manner than in an official capacity, (think litigation).

We are not going to solve this issue on this forum and should really consider the effects upon the families and colleagues affected by this, as well as individuals outside this sphere of operation who may not have the information to determine the veracity of the discussion.

beanie

26th Jul 2002, 07:05

I believe the blade is pure titanium unlike the tigers carbon fibre blades, but i do not know how the vibration is monitored other than the i-hums in the gearbox.

Heliport

26th Jul 2002, 07:54

Cyclic Hotline
Re "Any action taken by the moderator of this forum, was at my request."
That statement is open to misinterpretation. Just to avoid any possible misunderstanding: It's true you drew attention to Lu's post but I took action having read it myself and making my own judgment.

Lu
I stand by what I said in my previous post.
Heliport
Moderator

Lu Zuckerman

26th Jul 2002, 12:52

To: beanie

Following the lightning strike, the blade was returned to the manufacturer for evaluation before it was returned to service. Currently the investigation team is gathering more information about the history of this blade. At this stage, there is no evidence to link the lightning strike to the fatigue failure, however, this is one of the variables still under active consideration.

Let’s assume your are correct in stating that the spar is made of titanium alloy. If that were true the point of lightning attachment would have been seriously discolored.

Titanium has a strange property in that it will form colored oxides on the surface of the material when an electrical current is passed through it. The color can be varied with the increase or decrease in current level and all colors of the spectrum can be achieved with this variance. The voltage can vary from several volts to 50-100 volts in order to achieve the surface color change. If this relatively low voltage can effect the surface in forming the colored oxides then imagine what several million volts at very high amperage can do not only to the surface but the internal matrix as well.

:eek:

widgeon

26th Jul 2002, 13:03

According to Sikorsky site S76 blades have titanium spar ( s?) .
An earlier post referred to a secondary load path .
How is that attained ?
Neil

Lu Zuckerman

26th Jul 2002, 13:26

To: widgeon
I lifted this off of the North Sea crash thread. I can’t answer your question in regards to the methodology of incorporating a secondary load path on the blade(s). My statements were based on the facts as presented to me. If you want to know ..... etc ask Nick.
See my comments above.
Titanium spar.
To: beanie
quote: Following the lightning strike, the blade was returned to the manufacturer for evaluation before it was returned to service. Currently the investigation team is gathering more information about the history of this blade. At this stage, there is no evidence to link the lightning strike to the fatigue failure, however, this is one of the variables still under active consideration.
Let’s assume your are correct in stating that the spar is made of titanium alloy. If that were true the point of lightning attachment would have been seriously discolored.
Titanium has a strange property in that it will form colored oxides on the surface of the material when an electrical current is passed through it. The color can be varied with the increase or decrease in current level and all colors of the spectrum can be achieved with this variance. The voltage can vary from several volts to 50-100 volts in order to achieve the surface color change. If this relatively low voltage can effect the surface in forming the colored oxides then imagine what several million volts at very high amperage can do not only to the surface but the internal matrix as well.
Note: There is a museum in either Spain or Portugal that is made of mainly Titanium alloy. If this museum is ever hit by lightning it will turn all colors of the rainbow.
:)

Red Wine

26th Jul 2002, 14:16

Extending somewhat on what Nigel has skirted.......in that due to the extreme vibrations, no call was possible....!!

Years ago [seems like yesterday].....I can remember a crew that had a Rotor Brake Quill on a B412 let go.

The vibration was so great that their Headsets "flew" off their heads....hence no Intercom or Radio available........great, right when you need both.

Perhaps a helmet thread .........who's game???

S76Heavy

26th Jul 2002, 16:25

But if low voltages and amps can cause these oxides to form, surely the blade would have been rejected after being subjected to high volts, high amps in a lightning strike?

If such currents cause havoc with the titanium matrix, then I would expect the blade to have been scrapped. So either the damage, IF it occurred (as it's not clear from the AAIB findings just yet) was not apparent, or the check was not performed correctly, if I understand your statements correctly.

And as other operators have recently removed blades that have suffered lightning strikes in the past as a precautionary move, there must have been quite a number over the years that have been checked, found satisfactory and returned to service.

I cannot believe that if lightning had such damaging effects these blades would have been allowed back on aircraft. But then again, I may be proven wrong..

S76Heavy

26th Jul 2002, 16:35

About helmets, I've been told by a previous employer that pilots wearing helmets would scare the passengers into thinking that helicopter flying was a dangerous enterprise...:(

SASless

26th Jul 2002, 16:41

Sorry guys....but helmets would be totally useless in this event....when that blade let go....and the transmission left the aircraft with what was left of the bad blade and the other three blades.....head protection became a moot issue.

magbreak

26th Jul 2002, 17:39

In the ASB issued at the same time as the AAIB statement Sikorsky mention 8 blades that are known to have been involved in lightning strikes.

An amended version came out today stating that all blades involved in lightning strikes on the ground and in the air should be removed before the next flight.

t'aint natural

26th Jul 2002, 20:53

Death would have been mercifully quick for all POB in this - probably within half a revolution. The out of balance forces would have been enormous.

Red Wine

26th Jul 2002, 22:31

Yes I understand the visual impact on passengers....also that this highly unique S76 accident was "unsurvivable'....AABI words.

But....Offshore crews do undertake HUET, wear Cold Water suits, wear lifejackets, have a beacon in their pocket, CVR, FDR, IHUMS, and so on and so on.........but the most basic of personal protection..........nope, it's to hard.....but to hard for all the wrong reasons.

Visors protect against birds.......Helmets provide a better Db noise reduction [important if you are having a busy week].......and your prime communication system will be there when you need it.........

Not to mention the better protection for yourself.....number "One".

Remember if you survive the initial or subsequent "Incident'.... then the rest on board have a far better chance as well......

I am as guilty as the rest....if I am rostered to an Onshore Base or task......sure my helmet is part of my basic kit and would'nt leave home without it.. [and passengers don't blink an eye]

But if the boss rosters me over water...."Old Faithful" stays in the cupboard.

Makes good sense.......Yuh!!

Flying Lawyer

26th Jul 2002, 23:55

"It is entirely inappropriate that any employee of Sikorsky (especially of the stature of the very identifiable poster here) would make any comment at this stage of ANY investigation, or be requested to respond by any of us here.
Although immediate cause and mitigation may be defined, the completion of the investigation is a long way away and it is quite unreasonable to consider that anyone from Sikorsky would comment in any other manner than in an official capacity."

The above is an excerpt from a post by Cyclic Hotline yesterday.

Lu
When we have experts of the calibre and standing of Nick Lappos prepared to give their time answering questions on the Rotorheads, it's unfair to abuse that generosity by asking questions which even indirectly relate to an investigation in which they or their company is involved. It is equally unfair to encourage others to do so.

Nick and I are friends and in regular contact, but I wouldn't think of trying to take advantage of that friendship by asking him any questions about this crash or anything which might be covered in the ongoing investigation - any more than he would ask me about an aviation case whilst the case is still current.
Surely that's just good manners, and respect for a friend?
Nick is a good friend and enormous asset to Rotorheads. Let's be sensible and respect his position.

Tudor Owen

Flight Safety

27th Jul 2002, 04:45

I’ve read in a variety of sources that the S76 (including the A model) does indeed have titanium spares in the rotor blades.

The following information was gleaned from a Titanium Industries website, where an association promotes the industrial use of titanium, and I’m posting this in case the lighting strike had anything to do with the metal fatigue the AAIB detected in the fractured rotor blade. The information on how to machine titanium and especially how to weld titanium was particularly interesting. The physical property discussion will be limited to only those properties that would be relevant in a lightning strike.

Titanium reacts strongly with normal air when heated, so arc welding requires a pure argon “air blanket”. An arc welded titanium structure shows colors if contamination develops. A “silver metallic” color means no contamination, a gold or straw color means some contamination, and a light or dark blue color means high levels of contamination (the blue colors also mean no structural soundness at all). Contamination can produce porosity, low-notch toughness value, and brittleness.

Titanium comes in 3 classes of alloys that include 2 normal lattice matrix classes, and a class with a mix of the 2 normal matrix. The first matrix is “hexagonal closed-packed” (HCP) lattice structure (also know as “alpha phase”). The second matrix is “body centered cubic” (BCC) lattice structure (also known as “beta phase”). Certain alloys stabilize the titanium to one matrix or the other within certain temperature ranges (“alpha phase” class alloys and “beta phase” class alloys) and some alloys stabilize a mixture of both (“alpha-beta phase” class alloys). Various heat treatings and “annealing” also help to stabilize the matrix of the various alloys.

Titanium can undergo a matrix transformation known as an “allotropic transformation”, that can convert the matrix from one lattice form to the other, when heated to certain temperatures (depending on the alloy). If I understand it correctly something like an “allotropic boundary” (my phrase) can form within a structure when titanium is “spot heated”, causing one lattice (or mixture) to exist on one side of the “boundary” and a different lattice to exist on the other side. This can be a source of structural weakness and/or brittleness.

Titanium is also a poor conductor of heat, which must be watched when welding it. This property allows hot spots to develop more easily within a structure.

All of this would be relevant to a lighting strike, because discoloration would indicate that atmospheric gases (namely oxygen and nitrogen) might have contaminated the metal if the lightning strike heated it. Also, the current from a lighting strike could cause local “hot spots” along a high amperage conduction path. If a matrix change occurred due to heating, the conduction path could possibly be a source for fatigue in the metal.

None of this will be relevant though, if a lighting strike had nothing to do with the fatigue that caused the fracture of this particular rotor blade.

SASless

27th Jul 2002, 05:26

I guess the supposition about the connection of a lightning strike and the subsequent blade failure (even if no connection is found)begs the question of just what kind of inspection is done? Is the Titanium spar exposed for its complete length....or just a small area around the actual point of strike? Also, would it not be considered prudent for an operator to scrap the blade subsequent to the blade being struck by lightning? I know in general experience, lots of damage can occur to metallic components that are not adequately bonded and thus allow arcing between adjacent metallic surfaces with different polarity or with poor bonding. Having seen a few lightning strikes to electrical circuits and metallic structures, the amount of damage is quite impressive, thus the thought of flying around with a set of rotor blades that had experienced a lightning strike more than feels me with concern. Just how far will an operator go to keep a part in service until its mandatory retirement life? I wonder if economic concerns might have influenced the decision to retain that particular blade in service rather than accept a financial loss and write off the blade? Are the other blades that have experienced lightning strikes now going to be retested or will the operators concerned merely remove them from service and scrap them as a good operating practice?

SASless

27th Jul 2002, 05:39

Lu,

Considering the situation.....If I were Nick Lappos....I would take a very real hiatus from this forum for quite a while. If any of his posts were to be misconstrued, misquoted, or in any way be thought improper, untimely, or remotely likely to cause Sikorsky a problem.....our dear friend would be in very hot and deep water with his superiors. Out of respect for Nick......lets give him a pass on any posts for a while.....hang out there in the ether Nick....and stay out of harm's way!

LowNSlow

27th Jul 2002, 07:15

vertalop I sit corrected ;) We do indeed have two 212 s. :D :D I was thinking of the last job where we had 214's. Fortunately nobody has yet managed to drag me offshore on this job yet hence the mistook :D :D

I did point out that it was our operator that chose to ground the 76 rather than it being the CAA :cool:

Let's hope that the lessons learned from thei accident will bring about changes to the inspection procedures etc which will allow the 76 to restore it's good reputation.

Hummingfrog

27th Jul 2002, 08:20

In my old and bold days I flew Sikorsky designed Wessex and Seakings with similar blade designs to the S76. These blades had hollow spars pressurised with nitrogen and a BIM indicator at the root which was white if the spar was pressurised but turned to white with black stripes if the spar lost pressure due to a crack etc. A BIM may have given warning of the crack before the catastrophic failure occurred.
I believe that the S76 blade spar is a cold formed welded titanium tube which is then hot formed into the required aerofoil shape.

HM

ShyTorque

27th Jul 2002, 09:01

SASless,

Precautionary advice has been promulgated by Sikorsky that blades previously involved in lightning strikes should be removed (replaced with another) prior to the next flight. The onus to keep them in service has been withdrawn from operators (unles they really want to stick their necks out!) .

I heard of one such aircraft that is now embarrassingly stuck on a ship somewhere in the Med.

Lu Zuckerman

27th Jul 2002, 16:07

Lu
For some reason, you posted the same long post on two threads.
One now deleted.

Lu Zuckerman

27th Jul 2002, 17:00

To: Flight Safety
Isn't that what I said in my post above relative to the properties of Titanium?. There is a post I made on the Rotor blade failure forum.
Lu
Quoted passages deleted. If you want to refer to exhanges on another thread, please post a link.

I made several comments on a post that has since been removed alluding to [Edited again by Heliport]
An S-76 suffered a major lightning attachment incident and the following words are from an AAIB accident report. AAIB Bulletin No. 3/2001. Aircraft Registration Sikorsky S-76 (modified), G-BHBF This helicopter suffered major trauma and many parts were changed and many were replaced. (These are my words). Quote:…….The horizontal stabiliser was scrapped, being damaged beyond economic repair. The major components found to have been effected were returned to the manufacturer or approved overhaul agencies. In most cases no procedures for the necessary repairs existed. In other instances no effective inspection techniques appropriate to lightning events were available. Most of the major components were therefore not returned to service, but replaced using new or overhauled components. (Unquote) This question begs asking. If there were no inspection procedures in existence what criteria was used to return this blade to service? I am not implying that the lightning strike and the eventual blade failure had any thing to do with each other.
There is a post by Magbreak on the North Sea thread. Also there is an interesting post by Flight Safety on the properties of Titanium. If anyone wishes to read them, they can.
Quote: In the ASB issued at the same time as the AAIB statement Sikorsky mention 8 blades that are known to have been involved in lightning strikes. An amended version came out today stating that all blades involved in lightning strikes on the ground and in the air should be removed before the next flight. Unquote. Speculation deleted.
According to ATA regs. when an aircraft enters service the operator will receive copies of the required manusls to include a repair manual and an overhaul manual. In the case of the S-61s these manuals were never created (at least in reference to the two effected S-61s). Edited
:confused:

Heliport

27th Jul 2002, 22:23

We know from discussions following other crashes that opinon amongst members is divided about whether it is right to discuss possible cause(s) of a crash before the accident investigators have completed their investigations and published their report. I think discussion is inevitable and acceptable provided that contributions are responsible.

* Making allegations against manufacturers on a public forum is a fraught with dangers for the owners of the site.
* Alleging that negligence or some other failure by a manufacturer has caused a loss of life is irresponsible. If you feel your theory is right, find a newspaper or trade journal with sufficient financial resources to test your theories and publish them if they feel sufficiently confident.
* Saying "I will admit I'm wrong if in fact I am proven wrong" doesn't change the nature of the post. Nor does adding "I'm not implying that .........." when you obviously are.
* Inviting people to "ask Nick" questions about the S-76 which relate directly or even indirectly to the North Sea crash is irresponsible and unfair. As several people have pointed out, Nick cannot possibly be expected to answer questions on this thread.
* Claiming that because somebody hasn't answered a point to your satisfaction it must be because the answer would be damaging to their company is silly. Rotorheads is the leading helicopter website, but it is not an official investigation. It's particularly unfair to do that to someone who has given so much to Rotorheads.
* Finally, if one of your posts is edited/deleted, please do not repeat the deleted material in another post.

Please look at things from the point of view of the owners of this site:
Because we post anonymously, most contributors are just 'usernames' in cyberspace. The owners have no way of knowing whether an individual member is truly the expert he claims to be, a crank with a pet theory, or a disgruntled former employee of the company being attacked.
Pprune doesn't have the facilities to check whether an allegation is right or wrong. Apart from the potential financial implications of libelling a person or company, it is also unfair to allow people or companies to be attacked on a public forum when the allegations might be totally unfounded.

Heliport
Moderator

widgeon

28th Jul 2002, 17:42

No info on web on S76 blade contruction , If it was the same as blackhawk then one might assume it was a multi spar contruction ( similar to apache) , otherwise it would not allow for ballistic damage. Any one confirm it is multi spar contruction ?.

Hummingfrog

28th Jul 2002, 17:57

As I said in an earlier post the S76 blade has a single hollow titanium spar which is a cold formed welded tube which is then hot formed into the aerofoil section. Pockets are attached to the spar to complete the aerofoil section. The whole blade is then covered in a metal mesh impregnated fibreglass sheath. From the diagrams I have seen I can't discern any secondary load path.
HF

hobie

28th Jul 2002, 18:22

the following AAIB bulletin on G-BHBF on a lightning strike on the 17th Nov 1999 gives a good description of the Main Rotor Construction .......

http://www.aaib.dft.gov.uk/bulletin/mar01/gbhbf.htm

(this is not a report on the same machine by any chance?)

Flying Lawyer

28th Jul 2002, 18:57

You've probably all seen it, but the AAIB's preliminary findings are posted in full on the main 'North Sea Crash' thread.

It might be worth bearing in mind that the report says "At this stage, there are a number of variables that are being evaluated to determine the likely origin of the fatigue.
One variable may be related to a lightning strike suffered by the subject blade in 1999 but there are other variables under active consideration....................
At this stage, there is no evidence to link the lightning strike to the fatigue failure, however, this is one of the variables still under active consideration."

The bold is mine.

offshoreigor

28th Jul 2002, 19:23

Can everyone just please wait until the other section of blade is found before they start posturing about the cause of the failure? Until they get the missing section, they cannot put the whole puzzle together.

I myself am still waiting for SHELL approval to fly and I dont think that will come until they are convinced that this is not a design problem. So lets just wait and see.

:eek: OffshoreIgor :eek:

Hoverman

28th Jul 2002, 20:17

Well said.
Some discussion is natural, but I hope people keep to the guidelines Heliport has given. I hope Lu reads them before posting.
The AAIB are probably the best accident investigators in the world and they'll get to the bottom of what caused this tragedy. The lightening damage possibility is just one option, and it may turn out to be a complete red herring. We just don't know yet.
Jumping on little bits in a preliminary report and building them up in to something big is stupid. I suppose that's what sorts out true experts from people who claim they are.

magbreak

29th Jul 2002, 14:07

Hobie,

No it wasn't the same aircraft but it was the same base.

Having read the report one paragraph is still confusing me.

"The horizontal stabiliser was scrapped, being damaged beyond economic repair. The major components found to have been affected were returned to the manufacturers or approved overhaul agencies. In most cases no procedures for the necessary repairs existed. In other instances no effective inspection techniques appropriate to lightning events were available. Most of the major components were therefore not returned to service, but replaced using new or overhauled components."

(In flying lawyer style the bold is mine)

My questions are:

1) What exactly do Sikorsky or their approved overhaul agency do with a blade that has been hit by lightning??

2) Where the paragraph states "most of the major components were therefore not returned to service" is that a choice of the Operator, or the manufacturer?

Hoverman

29th Jul 2002, 16:11

Lu
Even though I can see why lots of people think it's wrong to speculate about causes before the official report comes out, I'm on the side of saying it's only natural to discuss so allow it as long as it's sensible. * Finally, if one of your posts is edited/deleted, please do not repeat the deleted material in another post.
If you keep ignoring the ground rules, this thread will end up being closed.
And it's bl**dy rude to just ignore the guidelines. Why do you always act as if you're a special case and the rules don't apply to you?
:mad:

Lu Zuckerman

29th Jul 2002, 17:44

To: Hoverman

1) What exactly do Sikorsky or their approved overhaul agency do with a blade that has been hit by lightning??

magbrake asked the above question and I responded. Perhaps there are other members of this forum that would like to respond to the same question. Maybe they could finesse the answer but the content of their answers will be similar to what I said in my response.

I believe that my entry into this thread was in response to a post that stated that the main spar of the rotorblades was made of Titanium. I posted some peculiarities of Titanium and another post added to it and in essence supported what I had stated and it went from there. I never stated that the lightning strike was the cause of the failure although it was alluded that I in fact did make those statements. My reference to the effects on Titanium by low or high voltage is that it would be noticeable at the point of attachment. My comments were in support of the AAIB investigating the relationship of the lightning strike to the fatigue failure of the spar. Up to now it has all been conjecture both on my part and the parts of the other contributors of this forum.

:)

Dave Jackson

29th Jul 2002, 18:53

Personally, I see nothing wrong with Lu, or anyone, speculating about any helicopter related subject, as long as the author makes it absolutely clear to all, respectful of different cultural interpretations, that certian comments are purely speculative.

______________________

To not lose the 'thread' of the thread, the moderator might;
1/ e-mail a copy of the offending post to the author, with a request that he/she edits it.
2/ then delete only the offending segment(s), awaiting the author's rephrasing of them.

Just my 2-bits worth.
(to non North Americans, 2-bits means a quarter, and a quarter means 25 cents, and 25 cents means nothing - if it's Canadian quarter) :)

Heliport

29th Jul 2002, 20:25

Lu
I assume Hoverman was referring to you repeating things which had already been deleted from your earlier posts - only hours after I had expressly asked contributors not to do that. You did the same thing earlier in the thread which is what prompted me to include that particular guideline.
I have deleted it again.

The guideline was clear: "* Finally, if one of your posts is edited/deleted, please do not repeat the deleted material in another post.

I have explained both here on the forum, and by email to you, what is and is not acceptable on Pprune. I know you consider our policy on these matters to be too restrictive and a denial of free speech. You are entitled to your views. What you are not entitled to do is to deliberately post in breach of the rules.

Moderators have a responsibility to enforce the policy laid down by the Adminsitrators. We are all volunteers with other jobs, and can't monitor the forums 24 hours a day, so we rely upon members' co-operation. Usually, it works.
I'm sure there are many members who from time to time disagree with Moderators' decisions, but there are only two Rotorheads members who persistently and blatantly ignore requests: You are one of them.
I am anxious to avoid any unpleasantness over this, but there is no justification for treating you any differently from everybody else.
Please read the Guidelines (and my email) again.
If you don't like the way Pprune is run, post your views on another website - or start your own.
If you wish to continue posting here, you must abide by decisions even if you disagree with them.

Dave Jackson

1st point: You are entitled to your view. Please refer to the 'Guidelines' post above to see the Pprune view.

2nd point: If Pprune had a full-time monitoring / editorial team, what you suggest might be possible. This entire website is run by people who have other jobs and other demands on their time. We rely upon members to co-operate by abiding by policy decisions even if they disagree with them.

leading edge

29th Jul 2002, 21:05

EMERGENCY AIRWORTHINESS DIRECTIVE

Date July 26, 2002

AD# 2002-15-51

Send to all US owners and operators of Sikorsky Model S76A,B and C Helicopters

"This Emergency Airworthiness Directive (AD) is prompted by the failure of a main rotor blade (blade) due to lightening strike damage. The condition, if not corrected, could result in the loss of control of the helicopter.

The FAA has reveiwed Sikorsky Aircraft Corporation (Sikorsky)
Alert Service Bulletin No. 76-65-55A dated July, 25,2002 (ASB). The ASB sepcifies reviewing the component log cards or, if necessary, other maintenance and operational records or the service istory to determine if a blade has been damaged by a lightening strike, either in flight or on the ground. If the service history cannot be determined, the ASB specifies removing the blade before the next flight. If the records indicate that a blade has been damaged by a lightening strike, the ASB specifies removing it from service before the next flight."

By the looks of it, the FAA thinks it was probably lightening.

LE

Edited for typo LE

Leading Edge has accurately quoted the AD, which can be read in its entirety at: http://av-info.faa.gov/ad/PublishedADs/021551.htm PedalStop, Rotorheads Moderator

S76Heavy

30th Jul 2002, 20:58

Come to think of it, will that make a lightning strike in flight a "Land as soon as possible" event?

magbreak

31st Jul 2002, 13:27

S76Heavy, if you're from the 'Bristow' side of the fence talk to Max and ask his underwear if it should be a land as soon as possible event :) :)

This is a metaphoric desciption. No underwear was damaged during the event.

S76Heavy

31st Jul 2002, 16:10

I wasn't quite sure whether it was "land as soon as practical" or "ASAP" according to officialdom. Nowadays I would not hesitate to drop it down onto the first available flat surface and have it checked out, but since BF returned to Norwich it might have been an " as practical".

I had heard part of the story, though.. :D

SASless

31st Jul 2002, 16:19

After reading of the damage done to BF after its lightning strike....makes one want to consider continued flight after any such event it seems to me. Bristow also had a Super Puma take a hit from a bolt of lightning as I recall......and the tail rotor blades suffered an amazing amount of damage or I am led to believe. You reckon Bristow might take a more conservative stance on continuing to use components involved in such occurrences?

Any Bristow North Sea pilots or engineers out there that can provide us some idea of just how prevalent lightning strikes are on the North Sea? Maybe someone can give us a summary of how much damage is being seen following a lightning strike?

widgeon

31st Jul 2002, 18:45

http://www.aaib.dft.gov.uk/formal/gtigk/gtigk.htm

Accident report of Puma lightning strike.

AS always the AAIB report is all ecompassing , how come NTSB ones never seem as big.

Hoverman

31st Jul 2002, 19:00

Interesting report widgeon.
To answer your question, and leaving aside the insular 'British is best' rubbish we sometimes get on these forums, I believe the AAIB's reputation as the world's best accident investigators is fair.
On the other hand, the US has the 'can do' FAA and we have to put up with the pettyminded, beauracratic 'you can't do that' CAA. :rolleyes:

widgeon

31st Jul 2002, 21:04

It may well be that the NTSB reports are no published on the web . The major investigations by the NTSB ( and Cdn TSB) are excellent . What I find surprising is the volume of AAIB reports of non fatal accidents.

The Sultan

1st Aug 2002, 01:33

Moderator's

With all of this Sikorsky protectionism going on, it would be fair play to cut off Lu, Unc, and HP Dumb from commenting on tilt rotors. Their ignorance shines in their posts and are based on nothing but flawed logic.

I hope you show the current restraint in the future. Relative to the past, we (who actually know what is going on) did have a lot of laughs over their posts. However, this was at this sites expense.

The Sultan:p

Lu Zuckerman

1st Aug 2002, 01:48

Lu
This post had nothing remotely to do with S-76 blade failure.

Your allegations against Bell have been deleted.

Do not repost what I have deleted.

SASless

1st Aug 2002, 07:59

We all know the British way of doing things is the "Best"....afterall they have been telling themselves that for hundreds of years. Maybe that is why it used to be an Empire?

Does it matter how you get to your destination.....so long as you get to the right destination? I guess that is why BA flys Boeings, and Air Bus aircraft.....and we all use the "British" space based navigation system....and the Brits lead the world in space stations...moon walks...and microchips......and Bristow flys errrrrr....non-British helicopters.

To our British members....please....we don't need to hear this "British is Best" bovine fecal matter. Get on with your input and save the propaganda for your local pub. Let's deal with facts....and reasonable conclusions drawn from ascertainable facts and data. After a couple of years of reading RH posts....would have thought you would have figgered that out for yourself by now.

Sorry, Heliport....didn't mean to usurp your perogatives here...but this needs saying every now and then for those on the east side of the saltwater divide that forget themselves.