S-92's Grounded [Archive]

Graviman

30th Dec 2006, 10:38

Hydraulic lines flex as a result of the pressure pulses causing them to try to straighten out. The norm for any hydraulic line is to try to install it in such a way that it can flex without contacting other lines or surrounding structure. They have steel braids inside to take the pressure, so would only leak after high hours with plenty of warning that they are going to go.

I imagine this was just an oversight on the installation of these lines, which was spotted by the maintenance engineer. The grounding was most likely a precaution.

Mart

unstable load

30th Dec 2006, 10:52

Graviman,

There could also be a wiring bundle routed with/over the lines and wires could be rubbing n the lines, or they could be rubbung against each other even. Or bad p-clipping, yes, I know they are new but that does not mean a thing.
It is scary how something as seemingly soft as an electric wire will work through a stainless steel hydraulic line in short order.

NickLappos

30th Dec 2006, 14:44

Grav and unstable have it right. The only reason they are on the ground is that the lines are factory parts, and not available locally (yet?) Once the chaffed spot gets to a certain depth, the tube is weakened enough to increase the possibility of a leak, so the tubes must be replaced.

Gomer Pylot

30th Dec 2006, 14:44

I thought that was supposed to be fixed after the PHI fire. Perhaps only a few were modified. I would have thought the new ones coming off the line would have the mod, but perhaps not.

NickLappos

30th Dec 2006, 16:25

Gomer,
There are quite a few lines! I don't know where this one is, but you can bet it is not the same one as that on the PHI aircraft.

cyclic

30th Dec 2006, 18:53

Nick

If this was a fixed wing carrying fare paying passengers would we have let the next line chafe?

I think the manufacturers need to up their game a bit when you consider the cost of these machines. A few teething snags is one thing but it is becoming a bit of joke when the operators are doing all the test flying.

Bit of a rant from a guy who has lost more than one mate this year....(not SK related)

unstable load

30th Dec 2006, 19:40

cyclic,
I have been involved (on the fringes) in the arrival of a new type of aircraft and seen the snags and hassles that have been found. All new aircraft have a "settling down" time where the maintenance guys have a learning curve and the manufacturer depends on their feedback to improve their product as a consequence of this.
I have seen avionics do things that had the tech reps puzzled, wires chafed through on panels and the structure, pipes chafing and cracks appearing where they were not expected.

Those of you who have bought new cars or bikes should know about recalls and things breaking. Aircraft are no different, except that they get more column inches if things go wrong.
For what it's worth, the new aircraft were not Sikorsky, but that does not make them any different.

sox6

30th Dec 2006, 19:44

New is no excuse.

unstable load

30th Dec 2006, 19:59

sox,

It was not presented as an excuse, rather as an observation of what happens when a new aircraft hits the road.

How else would you propose that the hours of flying and the input of the techs is gained?? Helicopters are already so expensive, now we should get the manufacturers to supply and fly them for free until they have all the bugs ironed out???
Similarly, GM should drive thousands of cars for years before they sell them.....:confused:

I am not looking to start a bunfight here, sox, rather I am trying to illustrate the difficulties faced by the manufacturers who build this equipment. Like Nick said, he does not know which pipes they were.

They could be in a completely different place because the operator in Norway is flying in different climatic conditions to the GOM and the stresses on the airframes would be different. Just like the 92's flying in Malaysia and Aberdeen will be different to the first one that goes to Australia.

SASless

30th Dec 2006, 20:23

Just how many 92's are in this fleet that had 2 grounded?

Can anyone name just one aircraft...fixed wing or helicopter....that did not have a learning curve and unforseen maintenance issues when first coming into service?

If anyone can recall the Chinook and the problems they had upon being fielded in substantial numbers in the '60's would laugh at the kinds of things the 92 has experienced. All these years later and the old girls are still around and going through their fourth or fifth rebirth as a higher Mk number....and some are being new built as well.

The Sikorsky S-61, S-64, CH-53 Family all spring to mind as well for being good machines after the initial problems were sorted out.

Why can we not expect the 92 to do the same?

sox6

30th Dec 2006, 20:29

Maybe there is not much to look forward to:
http://www.pprune.org/forums/showthread.php?t=254751

unstable load

30th Dec 2006, 20:30

SAS,
well put, most eloquent.:D :D

Sums it up perfectly.

Happy new year to all out there and may 2007 be better and safer than all before.

sox6

30th Dec 2006, 20:32

Sasless

'Maintenance problem' - with pipes that are only available from the factory??

NickLappos

30th Dec 2006, 20:36

SASless,

Thanks for the wisdom! Please see that sox6 has one goal - keep this thread near the top, and keep selling 225's (on top of the 4 or 5 already sold, that is.....)

I actually posted some dirt on EC in a previous thread that he was pumping, but pulled it down because his game is not mine. He cannot see the ditchings and broken tail rotors on his favorite helos, but the chafing hydraulic lines on two 92's drives him nuts. So be it.

The 92 is a fine machine, and will probably be a classic. The Norsk fleet is now averaging 2,000 hours per S-92 per year. I don't know any old, proven machine that has shown within 3/4 of that flight rate!

SASless

30th Dec 2006, 20:48

Sox.....please don't try to convince me every operator in the world has every possible spare part for every machine all the time and never go AOG for something that must be shipped from the factory after the machine has been grounded!:=

I stood over an Agusta factory AOG coordinator once upon a time and watched him send a message to a customer telling him the factory planned to manufacture the part he needed....nine months down the road!

sox6

30th Dec 2006, 20:51

Nick

Are you paranoid? Amazing how you bring other manufacturers into every thread. Still so has SASless - brief summary "the S92 is like any other helicopter" but perhaps a bit better with spares that Agusta. How dissappointing for you. So much for those new certification rules and a Collier trophy. By the way: Where the 332L2s at Norsk not also doing 2000 hours per annum back in the late 90s? And 1500 hours is low time for any North Sea machine these days. Have a look at the oil price.

I fly 76s by the way. But I never believe the hype.

SASless

Suggest 'production' more likely than 'maintenance'.
From what I here ther are a lot of spares shortages on the 92. Though of course they could be down to the operator's spares forecasting too.

Graviman

30th Dec 2006, 21:02

The 92 is a fine machine, and will probably be a classic. The Norsk fleet is now averaging 2,000 hours per S-92 per year. I don't know any old, proven machine that has shown within 3/4 of that flight rate!

2000 Hrs per year is going some! I know first hand how hard it is to capture every fault expected in the service life of a vehicle. Assuming the design process is not a million miles away from this:

Concept-->Prototype-->Development-->Prod_development-->Production

A realistic aim is to capture >90% of this type of issue at each phase after concept, this still leaves perhaps 1 part in 1000 that will require modification during production. I have not seen the BOM for this heli, but there will have been more than 1000 new parts on a project like S-92.

Mart

SASless

30th Dec 2006, 21:11

Sox,

As new as the 92 is...forecasting spares really falls more into "art" than "science"....over time that will cease to be the case just as in the 76 you fly now. When it first came out it left a bit to be desired as well....evidence the numbers of Mods but it has matured nicely.

sox6

30th Dec 2006, 21:36

SASless

Two words on the 76: "tail pylon". You can see more cracks there than a nights window shopping in Amsterdam. And the panels are taken off faster than... well you know the rest.

Nick is this one of yours?

"The size of your problem is defined by your efforts to convince yourself that it's not a problem."
- Nick Lappos Quote

SASless

'Over time' thing 'mature' in the long term right? Nick apparently has more to say on that:

"The long term is really just a bunch of short terms taped together."
- Nick Lappos Quote

And

"The service life of a cobbled up fix is inversely proportional to the time required to slap it together."
- Nick Lappos Quote

I hope they don't do that with the pipes!;)

By the way: all qoutes from http://www.inspirationalwoman.com/quoteauthors_view.asp?view=Nick-Lappos (http://www.inspirationalwoman.com/quoteauthors_view.asp?view=Nick-Lappos)
http://www.inspirationalwoman.com/images/3friends.gif
"a website for women who would like to share their writings which express their hopes, dreams, successes, and struggles related to reaching their highest potential in life"

Some PPRUNERS are so versatile. Germaine Greer must be proud of you Nick!

cyclic

30th Dec 2006, 22:06

except that they get more column inches if things go wrong.

ok, but when my car gets recalled its generally not life or death. Lets ramp things up a little and get the helicopter industry out of the pioneer age. We don't accept risk like this anymore and the industry should rise to the challenge. As I said before, if Boeing or Airbus was to hit the headlines with chafed pipes, twisting airframes, cracked tail pylons on brand new airframes the traveling public would revolt. This are real faults on 21st century aircraft.

sox6

30th Dec 2006, 22:40

Cyclic

Well said.

unstable load

30th Dec 2006, 23:14

ok, but when my car gets recalled its generally not life or death.

I remember hearing of an SUV that used to flip on the highway for no explainable reason that caused all sorts of noise in the USA.

I also remember people dying there.

SASless

30th Dec 2006, 23:19

HeliComparator

31st Dec 2006, 13:44

All newly designed helicopters (regardless of which way round the rotors go) have teething problems, some of which are quite serious. This is pretty much accepted by the industry and by many of our clients (one of which very sensibly requires at least 1000hrs on a new fleet before trusting it to their passengers).

But should it be like that? What is the point in having the certification process when so much slips through it. All it seems to do is prolong the development process, cost a fortune and lull us into a false sense of security. It is clearly not a robust process.

What it most certainly does is to make fixing problems take much longer. Your fancy electronic box has a software bug? Certainly Sir, we can fix that but it will take 3 months to redesign and then another 6 months to get it through certification ( at the end of which there will still be those bugs that we have not yet found!) and in the mean time you'd better get used to the bug!

Perhaps certification should be an internal manufacturer process but have strict rules that when an item is found to be non-compliant, buggy or self-destructive the technical management are publically castrated. That would make them pay attention though I suspect there would still be a lot of squeaky managers!

HC

Hilife

31st Dec 2006, 15:01

ok, but when my car gets recalled its generally not life or death. Lets ramp things up a little and get the helicopter industry out of the pioneer age. We don't accept risk like this anymore and the industry should rise to the challenge. As I said before, if Boeing or Airbus was to hit the headlines with chafed pipes, twisting airframes, cracked tail pylons on brand new airframes the traveling public would revolt. This are real faults on 21st century aircraft.

What sort of a facile statement is that?

I’ve lost track of the number of times a well known car manufacturer has had to recall up to several million vehicles due to exploding fuel tanks and faulty cruise control systems, both potentially lethal.

PHI recently passed 10,000 flight hours in just two year of OPS with only a handful of S-92’s, so they can’t be that bad on reliability and safety.

You show me an aircraft that’s never been grounded for lack of spare parts and I’ll show you a suspended museum piece.

Serious as it can be, if fretting of an oil line causes you this much concern, then don’t dare read through the list of ASB’s and AD’s that apply to a host of very well known and respected helicopters flying around our skies daily.

Having spent 10-years on Chinooks in the 80’s I can testify that fretting was something you lived with and if you’ve ever been onboard at 155 Kts you’ll understand why.

Sadly, even Boeing and Airbus have witnessed some pretty catastrophic events even in recent times. However, with a 737 taking off every 5-seconds worldwide, you are able to bring their safety into context and this is likely to apply to the S-92 as well.

Just about every decision you make every day involves risk, from what food you eat to where you cross the road and that’s before you risk the consequences of defying gravity.

It’s not in the interests of any manufacturer to play with safety, but if its zero risk you demand then may I suggest you keep your toes under the quilt all day.

Aesir

31st Dec 2006, 15:03

All newly designed helicopters (regardless of which way round the rotors go) have teething problems, some of which are quite serious.

Yes. The Westland W30 and Mitsubishi MH2000A come to mind :ouch:

http://www.whl.co.uk/images/history_w30_100.jpg
The W30.

cyclic

31st Dec 2006, 15:31

f you’ve ever been onboard at 155 Kts you’ll understand why.

Yep, been on one of those at maybe 150kts. I read the ADs for a brand new helicopter everyday (obviously one day older at a time). I would like zero risk and so would the guys and gals down the back, believe me. I am not risk adverse, have flown for 22 years and am still here. What I would like is that a multi-million pound/dollar/euro aircraft isn't tested on a regular basis by the crews that have to fly them. I want value for money.

As for being "facile" (of little value but easily achieved), no, just my opinion which I think in cyberspace is just as worthy as yours - unless you're a military QHI of course;)

Geoffersincornwall

31st Dec 2006, 15:46

Yes new helicopters can be a step forward in technology ..... and a step back in reliability..... for a while anyway. Usually they will mature and improve like a fine wine. I was once asked to advise an oil company manager who was responsible for drafting helo service contracts "what is the maximum age we should accept for our fleet?"

I tried my 'fine wine' bit on him but not being a native English speaker this notion seemed lost on him...... or maybe he was a beer drinker!!

Anyway, we settled on 15 years as the maximum age for any helo in the fleet that serviced their contracts.

What comments on this notion I wonder?

Where will the 92 be in 15 years? Will the A model 92 be a much sought after 'classic' or will the B or C or even D model have consigned it to an early grave?

G

:ok:

Wizzard

31st Dec 2006, 16:04

As I read many years ago and have no reason to disagree:

"Never fly the A model of anything" :O

Wiz

sox6

31st Dec 2006, 16:26

Though Aseir points out not all the A models lead to a B model, sadly someone has to fly the A model for any progress.

hilife: I agree with your point that helicopter flying is not a zero risk activity, but it is not reasonable to expect a high standard of design & manufacturing? Chaffing pipes may not be a new problem, but thats all the more reason not to have them with a new design surely? Is it not reasonable to actually get some improvement on the previous generation of aircraft?

If a 737 takes off every 5 seconds, the PHI reaching 10.000 hours with the S92 is harldy a conclusive track record.

MamaPut

31st Dec 2006, 17:20

G in C,

Other than just pulling a figure out of a hat, what led you to recommend 15 years as the maximum life? Surely it depends on type of usage, hours flown, climates in which it's been operated, maintenance history and many, many other factors. There are many S61s, 76s, 212s, 365s, 355s, 350s, 206s, plus many others out there which are considerably older than 15 years and fly safely every day. Surely you remember that when the S76 first came out, as a new helicopter it killed GH :mad: . Surely age is just a meaningless number - it's what's happened along the way which should count more.

NickLappos

31st Dec 2006, 18:20

MamaPut,
You bring back memories, some very painful. GH was a friend, and the 76 was my baby, so that one was especially awful.

I think you correctly ask about something that this thread explores - how much can we get right at the start, and how much do we have to rely on customer support and engineering refinement to solve.

The "pipes" mentioned in this thread are specially shaped titanium lines that seem to have been chafed by wire bundles that are possibly different on every aircraft, the product of the different equipment packages that each customer insists on. Learning how the bundles must be strung, and how they move after several thousand hours (and perhaps also several maintenance cycles) is not entirely predictable at the factory, I think. I recall that there are about 20 miles of wire in every S92, so the task is not as trivial as some of the Cotton Mathers would have you believe, else the Airbus 380 would be blackening our skys already, instead of being 2 years late.

There seems to be a puritanical standard held here where absolute perfection is required. Not a bad standard, but one that is certainly not met by the Boeings and Airbusses that folks below mention as if they had no flaws on introduction. It is a facet of popular thought that what we don't know, we believe to be perfect. Not at all true, guys. The Boeing service bulletin stack for a 777 looks a lot like one for an S76 or a S92, but perhaps 20 times thicker (warranted by its greater number of parts).

A few chaffing lines will be replaced, the bundles moved an inch or so and those two aircraft will fly on. Perhaps they are already back in service.

Regarding how fit those aircraft are in their first year, the customer bought about 6 more after several months of using them, and the 2000 hours per annum they are averaging is better than any other helo of any type that I know of this last year, including tried and true models from the puritan's favorite manufacturers. Something's going right.

MamaPut

31st Dec 2006, 19:16

Nick,

GH was also a dear friend of mine, but his accident just seemed to illustrate the futility of blaming accidents on design flaws or age as absolutes. There is no such thing as the perfect machine and some things as geoffers mentioned do improve with age (until they get to the point where age-related failures occur - this in any machine, even a human one, is a difficult-to-predict variable). When GH had his accident, it didn't make me want to stop flying or never fly a Sikorsky again (I was flying another, older Sikorsky model at the time). When another dear friend died flying an old Eurocopter model, but with a new problem, a few years ago it also didn't make me want to stop flying or never fly another Eurocopter model.

I think some posters have a slightly simplistic approach to these sorts of problems. It's no good trying to compare a helicopter to a car and say that we're all test pilots for a new model. Helicopters are many times more complicated than cars, and have production runs which are often in the hundreds rather than in the tens of thousands. The majority of helicopters, because they do work of which only they are capable, work in hostile environments. How many cars, 5 hours or more a day, on a daily basis are loaded up to maximum design weight and then operated at maximum design power (sometimes more :\ ) many times a day?

So we have to accept flaws. Everything in life is flawed to some degree. The most important thing surely, is to recognise flaws as soon as possible, then either fix them (not always economically possible), or put in place procedures to nullify or reduce the dangers arising from them.

Geoffersincornwall

31st Dec 2006, 19:31

Not a lot of science I'm afraid but there is a correlation between the age of the machine (as opposed to the length of time that that particular type or model has been on the market) and the amount of tlc needed to keep it going.
This last year I've been flying a model (76A+) that is basically 30 years old although the machines we had were 20 years old or thereabouts. They, believe it or not, managed to clock up over 2,000 hours per annum ........for a while. Now they look and feel shagged and you wouldn't want your sister to fly in them if you judged them on looks alone.
Part of the psychology of passenger management is the correlation between the age of the aircraft and their confidence in it. Generally they like 'new' and don't like 'old'. You and I may know different but in their world they tend to oversimplify these things.
There is one national oil company in Europe that set 10 years for the max age for any helo on contract and our 'B' model 76s were squeezed out by that rule. I feel a little happier with a policy that 'no machine should be older than 15 years when tendered'
I think we will all be fascinated to see how the 'B' model S92, the 'B' model AW139 and the 'D' model S76 fair when they come into service. Reckon they will all be the dogs dooddas and maybe deliver that order of magnitude improvement in technical reliability we all crave.......... provided of course that there are enough engineers with the skills to maintain them and good enough training systems for the young men stepping forward to fly them.
G
:ok:

unstable load

31st Dec 2006, 22:06

Mama Put,

I was trying to draw a comperison between new vehicles of any sort. It was never my intention to minimalise the technical issues under discussion here.

Geoffers,
Has there been any form of "learning curve" from a technical point of view with the introduction of the C+ compared to the "old" 76's? I ask because I have not worked on them, but I did hear of problems that led to a thread of their very own on this forum.

EVERYBODY,

HAPPY NEW YEAR, BLUE SKIES, HAPPY FLYING.

Geoffersincornwall

1st Jan 2007, 01:23

The only comment I can make about the C+ is one based on the observations of a certain South American tech-rep who told me horrible stories about how folks with 20 years of 76A model experience had absolutely no appreciation that the C+ was so different it was virtually a new type. Trying to treat the C+ like any old A model had its repercussions and boy did the ginger beers screw up big time. We can only hope that other stations graduating to the C+ from previous models listen to the boys at the factory. There used to be an old saying,

If it looks like a duck, walks like a duck, swims like a duck and quacks like a duck then the damn thing's a duck - well it aint........... it's a C+ and this thing is different - it just looks the same when it's on the end of the flight line but believe me the RFM says different in big letters.

Have only flown the C+ sim so can't contribute much to any chat about how good it is but my mates fancy it and the ++ is apparently even better.

Have a happy and prosperous 2007 and may your logbooks continue to record the same number of landings as take-offs.

G

:ok:

mayotte

1st Jan 2007, 01:29

The C+ is actually almost identical, the only new thing is the control of the engines by DECU (unless you have also IIDS). I fly A, A++, B, C and C++ and a differences course is all that is need (provide you have an instructor with proper understanding - and many don't :ugh: )

Geoffersincornwall

1st Jan 2007, 08:16

My apologies for lapsing into the local vernacular. A 'ginger beer' is, in rhyming slang, the name for an 'engineer'. In other words it was the technical application of the differences that caused the grief.

That said I'm not sure I would like to jump into the SPZ7000 from the Ham Stan, the Trimble 2000 to the Garmin 500 or the C30 to the FADEC of the C++ with just a 'differences course' unless that course was carried out in the recipients native tongue by a sim school that knew the difference between 'attending' a course and 'passing' a course.

We were specially handicapped down in my favorite corner of South America because it was de rigour to 'appoint' instructors rather than 'train' instructors despite the regulations.

This has inevitably led to the blind leading the blind when more complex types are introduced into service. Add to this the lack of a simulator culture, a general lack of quality training of any kind in the offshore community and we have a powerful recipe for lack of competence amongst a workforce that has tremendous ability and potential - if only the 'system' would deliver the necessary training and the 'system' took a look at the goings on in other parts of the world (FAA/JAA/Shell/Exxon-Mobil/Total etc.) and learnt from them.

It doesn't help to have the worlds largest concentration of helo sim schools locked up behind a visa system that makes it very difficult for the would-be student to actually get there. Maybe that wrong will be righted in the coming years.

Sorry about the thread-creep - at least we are keeping the mudslingers in their prams and getting away from the usual pointless Sikorsky-Eurocopter slanging match.

2006 ended on a very sad note for the offshore guys in particular but the sun is shining on this New Year's morning, I'll take that as a sign that we are in for a brighter 2007.

Now I've got to shake off the hangover and help the wife tidy up after last night's celebrations. The best to you all from a bright but blowy south western corner of UK.

G

:ok:

finalchecksplease

1st Jan 2007, 08:23

Mayotte,

Doesn’t every C+ has the IIDS & DECU and it’s the C that just has the DECU?
The C’s I flew where like that but the S76 fleet is not really known for “standard” instrumentation packages so I’m not 100% sure.

Greetings & happy New Year,

Finalchecksplease

unstable load

1st Jan 2007, 10:43

Geoffers,

Thanks for illustrating my point to a degree. An almost identical aircraft that was giving the techs a headache. The physical differences under the cowlings are almost sure to have led to things rubbing/chafing etc and this on a 30 year old type.

I think it is a grand thing to aspire to perfection and totally accurate and intuitive CAD, but the facts of the issue are that PEOPLE still assemble them and they are not infallible.

Blue skies for 2007 all of you.

mayotte

1st Jan 2007, 11:38

finalschecksplease

The S76C doesn't have a DECU. It has Arriel 1S1 engines and the only real difference between it and the 76A++ is that A++ is an upgraded A+ (gearbox beef up), whilst the C was built as a C from scratch and has the more powerful gearbox installed on the production line.

Yes all C+ models have DECU as they have the Arriel 2S1 engines fitted. The older models were fitted with conventional engine instruments and DDR (DECU digital readout) and the IIDS came along later.

500e

1st Jan 2007, 16:08

The SUV thing is typical of any short wheel base, high Center of Gravity vehicle. Lord knows the US Army Jeep killed more GI's than did the enemy....certainly the case for the M-151 Jeep of the Vietnam War Era.
Modern pickup trucks now have the fuel tanks "inside" the frame rails vice outside as they did for ages. That was the result of accidents, research studies, and changes in the Federal law.
Nothing is as unforgiving as the Air when combined with gravity. The Sea runs a very close second. Neither of which surpass a woman scorned!

SAS do we expect a upgraded Woman scorned CC+++ perhaps ? (had mine for 35+ years pretty much no down time , value for money is still unbeatable, best deal of my life )
But I tend to agree with you regarding customers receiving value whatever they spend money on, if the manufacturer had to reimburse fully for down time some of the long waits for bugs to be sorted, spares to be made, available would disappear.
The reply we get to to queries complaints to manufacturers are 1, your the only person with this problem! 2, not heard of that before, will look into it.
Then either AD to say shorter examination times or replace parts at lower life ALL extra cost to operators, without FULL recompense.
I fully understand that problems arise that no one can envisage,but previous contact regarding, spares, maintenance, will affect the way you react and your tolerance to delay if you are a P***d off due to spare delays, you are already checking the bottom line, and will not feel it is up to you to be reasonable.