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Helicopter crash off the coast of Newfoundland - 18 aboard, March 2009

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Helicopter crash off the coast of Newfoundland - 18 aboard, March 2009

Old 18th Nov 2009, 21:41
  #521 (permalink)  
 
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While we're on the topic of gearboxes and probablilities, does the current FAR also require a 30 minute run dry demonstration on intermediate and tail rotor gearboxes?
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Old 18th Nov 2009, 22:49
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While not related to S92 I have witness 2 MGB fail, Hughes 500 and Skycrane. One broken input pinion and the other planet gear dropping through the gearbox. While uncommon not impossible hay? Then of course 2 famious MGB failers this year.
Now back to the S92
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Old 18th Nov 2009, 23:13
  #523 (permalink)  
 
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Cefoskey

Only 17 perished in the S-92? I guess the Korean who died and all those injured in a fully IFR 92 crash in marginal weather do not count.

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Old 18th Nov 2009, 23:34
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Past performance is not an accurate indication of future risk.

--------------------------------

1500 hrs in the 212, seen 0 oil press on the C-Box twice. It doesn't scare me away from the type but it makes me pay attention. It is the same for the other types I have flown.

One should never forget that we do our best to see problems coming and minimize or mitigate their impact. That's our job. It upsets us when there are issues we cannot anticipate, prevent, or deal with.

--------------------------------

I work in a war zone and assume the risk of people shooting at me. I don't believe that that impairs my appreciation for a reliable aircraft. I don't see this being different for military pilots.

--------------------------------

I lost a former student in Cougar 491 and I have seen the environment they were flying in. Given the choices available to them, I would never say they did less than their best.
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Old 19th Nov 2009, 00:01
  #525 (permalink)  
 
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I guess the Korean who died and all those injured in a fully IFR 92 crash in marginal weather do not count.
What the hell has that got to do with anything (that relates to this thread topic)?

The aircraft was being landed at an innappropriate site in mountainous terrain in poor VFR conditions. It was flown through a bunch of trees into the ground. If it were not for the aircraft's basic crashworthiness, a lot more injuries and fatalities would have resulted - in fact the owner thanked SAC for providing such a strong airframe and promptly ordered a replacement! (Not sure if the crew received similar praise!)
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Old 19th Nov 2009, 05:35
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212man

Just correcting Cefo's mis-statement that the Cougar 17 were the only fatalities ever in the 92.

The Sultan
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Old 19th Nov 2009, 05:52
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So, according to FH1100's logic, any system failure that hasn't happened to him in 32 years doesn't need to be considered when certifying new aircraft - well that'll make the job much easier and give people a nice warm feeling then

The number of MRGB oil losses was legendary on the Sea King (a Sikorsky helicopter) until finally the Emergency Lubrication System (ELS) was fitted - how did Sikorsky not learn this lesson and provide proper backup in their brand new helicopter??

All this cobblers about never flying the A model of anything might have been acceptable in the 60's but in the 21st century should not be even lightly entertained as normal practice.

I agree with DM - how is the certification still valid???
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Old 19th Nov 2009, 09:03
  #528 (permalink)  
 
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Here's my PAX (and layman's) view of the current situation.

S-92a certificaton should be robust enough to ensure that system design meets all operational requirements, which for offshore means no MGB lube oil leaks, and if one develops then the tranny can last long enough to get safely back to non-hostile terrain i.e. land.

Landing in the drink, whether controlled or otherwise, is the very last resort. Perhaps a tailfin like the Blackhawk would have helped 491 during an AR attempt, perhaps not. Moot point if a controlled landing under power was attempted and SS6 flotation was installed to give PAX a chance.

We have several PAX refusing to fly this helo now on safety grounds via their right to refuse unsafe work, initially after the recent public interview by Robert Decker on the issues with sitting in a non-window seat, now reinforced by the MGB mounting feet cracks. No MGB should develop cracks within 10 hours operation, period, that's just a basic design flaw.

The more publicity on these matters, hence this posting on this public thread, the better. SKY, or SAC or whatever you wish to call them, how about SIKORSKY, have a huge amount of work ahead of them to repair their damaged reputation with this A/C type. Settling out of court with the families of 491 will not be suffice, the ongoing enquiry and pending TSB report will make sure of that.

Safe flying

Max (currently offshore waiting for the new HH HTS-1 flight suit a.k.a. orange body bag to be rubber-stamped by some Transport Canada employee in Ottawa)
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Old 19th Nov 2009, 11:04
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Angry

I am living near much less hostile environment (Adriatic sea) but during some
winter storms, sea shows real nature. Last ditching incident was more than 30 years
ago when one Mil Mi8 T crew made emergency landing near shore line after some
tail rotor heating elements separation in flight causing intensive tail vibrations. Most of PAX drowned. Later investigation find out that crew response, to shut down and autorotate to ditching in sea, without emergency flotation, was mistake.

Out of some recent incidents we can be sure that most of Western
helicopter industry unfortunately approaching to serious technical problems
much in way, like our friend BMax claims "Ostrich engineering"....

Remember AW Tail on AW139
Remmber 2005. S76 Copterline near Tallin, when 14 people perished.
Copterline Flight 103 - Wikipedia, the free encyclopedia
And this last unfortunate S92 issue...
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Old 23rd Nov 2009, 00:36
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NEWS UPDATE NOVEMBER 22



Model of chopper that crashed off N.L. failed first test by 20 minutes: FAA


By: Michael Tutton, THE CANADIAN PRESS



HALIFAX, N.S. - A test to certify the model of helicopter involved in a fatal crash off Newfoundland showed it would remain airborne for "around 10 minutes" - about one third of the time required - if oil leaked from its gearbox, aviation regulators say.
Weeks after the crash of Cougar Flight 491 in March, European aviation authority documents revealed that the gearbox of the Sikorsky S-92A model hadn't passed a test that required it to run for 30 minutes without oil in order to meet a safety standard set by the U.S.-based Federal Aviation Administration.

According to additional documents obtained by The Canadian Press on the same Aug. 6, 2002, test, the gearbox fell about 20 minutes short of the goal when it was run at moderate speeds after oil was rapidly drained.
But Sikorsky says it has proven to aviation authorities that the chances of an oil leak from the gearbox housing is extremely unlikely and that the installation of a bypass valve resolves the only identifiable cause of a main gearbox oil leak.
The documents, obtained from the FAA through access-to-information legislation, outline a discussion between American and European aviation regulators on tests of the gearbox.

The European regulators said the test showed a loss of oil would mean the helicopter could only stay in the air for "around 10 minutes," a finding Sikorsky does not dispute
.
FAA spokesman Les Dorr said the test, meant to simulate a "catastrophic loss of lubrication," was stopped at that point.
After the test, Sikorsky and the FAA agreed that the only clear risk for an oil loss would come from an oil cooler that fed into the gearbox.
A second test was then conducted on Nov. 16, 2002, to see if a bypass valve - which pilots would activate by pushing a button - would provide oil to the gearbox if the cooler were to fail. The system worked well and the gearbox kept going for hours.

Sikorsky spokesman Paul Jackson said the company demonstrated to the FAA and European regulators that the probability of a leak from the gearbox housing was "extremely remote" and that installation of the bypass valve "addressed the only identified, non-extremely remote possibility for a main gearbox oil leak.

"It is very important to note that while the Cougar accident was indeed a very tragic event, the worldwide S-92 fleet has about 185,000 operational hours without any other incidents involving this injury," Jackson said in an email.

But in the documents, the European regulators question whether the cooler would be the only likely source of oil leakage, and they asked for information on other possible failures on the main body of the gearbox itself.

Sheldon Peddle, a union leader representing the oil workers who still fly on the helicopters off Newfoundland, said the 30 minute dry-run test is an industry standard which allows pilots more time to react and the possibility of reaching either land or an oil platform.
Peddle said 10 minutes "may meet the legal definition of whatever the FAA has in the regulation," but his view is that it "doesn't meet the expectation people in the industry would have."

Per Gram, a recently retired pilot who tested the S-92A in Norway, said he believes the FAA shouldn't have allowed the certification after it learned of the results from the first test.
"I disagree fully with the FAA for allowing Sikorsky to pass that test on that basis," he said, referring to the second test of the bypass valve.
He said he believes the 30-minute standard should have been maintained for certification purposes of the Sikorsky S-92A.
"It (10 minutes) doesn't allow for human error ... as a passenger, I'd be scared stiff if I knew about this," said Gram.
But Jackson said 10 minutes is sufficient because the flight manual for the S-92A requires pilots to "land immediately."
"The S-92A is certified to fly at a maximum altitude of 15,000 feet. At a comfortable descent rate of 1,500 feet per minute, the aircraft could be on the ground in 10 minutes," he said.

Sikorsky documents used to market the aircraft, dated August 2003, said the gearboxes of the S-92A have a "30-minute drive system after oil leak."
Jackson said this claim was valid because Sikorsky's gearbox had passed the second test showing the bypass valve worked.
"That language is fully compliant with the ... requirement to prove 30 minutes of flight after detection of an oil leak," he said.
"We proved this by assessing the probability of a leak from the gearbox housing as extremely remote."

The Transportation Safety Board is still investigating the cause of the Cougar Flight 491 crash, which killed 17 people.
But the independent agency has said that studs had broken on an oil filter attached to the main gearbox, resulting in the loss of a large quantity of oil.

It also has said that it took 10 minutes and 47 seconds between the time that pilots reported the loss of oil and when the engines were turned off.


...
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Old 23rd Nov 2009, 02:52
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Couldn't the oil companies take on the leadership role here ? They're the biggest, richest, most powerfull lobby group on the planet - since when if they really want something do they sit back and listen to a myriad of reasons why something can't be done from equipment manufacturers or anyone else ?

This 30 minute wording "requirement" was first "required" what, over 20 years ago ? Well this is 2009, and we're flying 90 minutes out into the North Atlantic, so maybe someone should take another look at what's "required" today.

And before all the naysayers start protesting about the cost, and the weight, and the space limitations, and the engineering, just how fast did it take for someone to engineer a delivery system for a hulking big spare tank of aviation fuel to extend the range ? (don't even want to get into the discussion of where it's located).

Is the technology already there, but it was decided we're not going to use it because...................?

Maybe big oil should say look enough of this debate based on a twenty year old 30 minute wording regulation, here's what we need based on our current and future operating requirements, make it happen - who's going to tell them no, you can't have that ? (especially if military was pushing the same issue).

Given that there's an ongoing accident investigation, public inquiry and possibly litigation at some point, a few choice phone calls from certain CEO's who wanted to change their "requirements" would set a fine example and probably get things moving pretty quickly.
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Old 23rd Nov 2009, 03:56
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Couldn't the oil companies take on the leadership role here ?
You may be surprised by what measures they have taken (well, one of them, anyway) with regard to this type.
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Old 23rd Nov 2009, 04:56
  #533 (permalink)  
 
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Madrock

As DCVC has highlighted, you can rest assured that SOME oil companies will be letting Sikorsky know what they think. You can also be reasonably certain the Sikorsky are doing something in response.

The 30 minute requirement was introduced in 1988 via Amdt 26 to JAR 29. You may think this makes it outdated, however by aviation certification requirements this is still relatively new. In fact I believe there are only two heavies that have been certified against this requirement - the S92 and EC225 (I am assuming the AW139 is a medium). Technically the 30 minutes is demanding, which explains the "modifications" both manufacturers developed after the basic MGB run dry tests failed. Even the superior level of safety the EC225 glycol spray system offers, it only provides 30 minutes flight at 80 knots. So approx 40nm then it's "Land Immediately". The bottom line is that the regulators can only ask for what is technically feasible and economical (ALARP if you will). The regulators are also the policeman of the rules, so they have the say when it comes to accepting compliance. Rightly or wrongly, the FAA, EASA and Transport Canada have all accepted S92 compliance against FAR 29.927. Maybe they should be getting more scrutiny and questioning than has been seen so far regarding their decisions?

As for the internal fuel tank that Cougar have fitted. Acceptance of that is down to Transport Canada. Some regulators around the world would not permit such a fit
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Old 23rd Nov 2009, 16:36
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A "certain someone" who used to work for a major manu...okay, let's just say it...Sikorsky wrote extensively on this board about the tests SAC did with the S-92 transmission to prove that it could run "for hours" after an oil leak. However, his description of the test was a little...oh...incomplete. He did not say that *all* of the oil leaked out. In fact, there was a leak but the leak was stopped.

We later found out that the test consisted of producing a leak in the lines leading from the transmission to the oil cooler, or perhaps in the cooler itself. After detection of the leak, a bypass system was activated, isolating the oil cooler but stopping the leak. In this mode with uncooled oil of reduced quantity, the transmission was able to run for...what was the duration...2.5 hours? Which the SAC rep seemed to brag about.

What he did *not* brag about was what happened prior to that test. We learn about that from the report noted in madrock's post.
According to additional documents obtained by The Canadian Press on the same Aug. 6, 2002, test, the gearbox fell about 20 minutes short of the goal when it was run at moderate speeds after oil was rapidly drained.

But Sikorsky says it has proven to aviation authorities that the chances of an oil leak from the gearbox housing is extremely unlikely and that the installation of a bypass valve resolves the only identifiable cause of a main gearbox oil leak.
Err...how's that again?
The documents, obtained from the FAA through access-to-information legislation, (ed. note: a FOIA request) outline a discussion between American and European aviation regulators on tests of the gearbox.

The European regulators said the test showed a loss of oil would mean the helicopter could only stay in the air for "around 10 minutes," a finding Sikorsky does not dispute
.
FAA spokesman Les Dorr said the test, meant to simulate a "catastrophic loss of lubrication," was stopped at that point.
After the test, Sikorsky and the FAA agreed that the only clear risk for an oil loss would come from an oil cooler that fed into the gearbox.
Well...
A second test was then conducted on Nov. 16, 2002, to see if a bypass valve - which pilots would activate by pushing a button - would provide oil to the gearbox if the cooler were to fail. The system worked well and the gearbox kept going for hours.
So. In August of 2002 Sikorsky tested their transmission without oil. It lasted about, oh, 10 minutes. And...what a co-inky-dink, Cougar proved that to be true in their real world application of that test! SAC had to come up with something, and three months later, by November of 2002 had devised the bypass valve, which the FAA accepted. Whether this system was "in the works" back in August is unknown at this time. But the time delay between the two tests is curious.

I'll bet that there are a couple of people within the FAA that dearly wish their signatures could disappear from the certification approval documents.

Me, I go either way on this. On one hand, I see SAC's point that transmission failures are relatively (extremely?) rare. On the other hand, it is interesting to see the lengths companies will go to creatively interpret and/or get around a regulatory requirement.

But in the name of God, who could miss that big ol' oil filter bolted to the side of the transmission? Who could look at that and *not* think that there's even a remote chance of a leak developing there? Methinks that the FAA's Les Dorr is sweating a bit right now. Or at least squirming uncomfortably.
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Old 23rd Nov 2009, 18:21
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FH110 Pilot,

Don't miss the irony of this statement:

Sikorsky spokesman Paul Jackson said the company demonstrated to the FAA and European regulators that the probability of a leak from the gearbox housing was "extremely remote" and that installation of the bypass valve "addressed the only identified, non-extremely remote possibility for a main gearbox oil leak.
Let's hope it wasn't made after the second 'extremely remote' uncontained loss-of-oil-failure within six months.

Jim

Last edited by JimL; 24th Nov 2009 at 10:35.
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Old 23rd Nov 2009, 18:50
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DCVC
Glad to hear it, because waiting for regulators is pointless.

VL
The bottom line is that the regulators can only ask for what is technically feasible and economical (ALARP if you will). The regulators are also the policeman of the rules, so they have the say when it comes to accepting compliance.
Well I guess then 20 years ago they thought it was technically feasible but very little has happened since. And if the policeman screwed up when writing (his own) rules, you don't want to expect the same policeman to admit he made a mistake, either during certification, or throughout operational life. And if we're waiting for the politicians (the policeman's boss) to do something good luck.........

The point I was trying to make is regulators will never be the drivers of technological advancement - they tend to follow along with manufacturers' current capabilities - they then update a handbook with minimum requirements, so in fact they're always behind the technology curve, not out in front pushing it.

Offshore operations have changed in the last 20 years - commercial manufacturers will only react to market demand (no demand, no change) - the oil companies have to play a bigger role in making sure manufacturers keep up as they go further and further offshore in hostile environments.

What happens when we go 2 hours offshore - everyone still busy debating the old 30 minutes wording ?
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Old 23rd Nov 2009, 21:10
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Oil filter

"But in the name of God, who could miss that big ol' oil filter bolted to the side of the transmission? Who could look at that and *not* think that there's even a remote chance of a leak developing there? Methinks that the FAA's Les Dorr is sweating a bit right now. Or at least squirming uncomfortably."


Hindsight is 20/20 most of the time. I've never had an oil filter leak so if you asked me what the risk was I'd have pointed to hoses, clamps, drains and every other point than the filter or it's mount. Granted, I'm just one old guy without all the input that the FAA or any other regulatory body gets, but how many oil filters have you ever heard of that caused a problem?... Unless the darn thing wasn't wired and locked....which isn't the problem in this case.

Fatal reality checks are a bitch.
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Old 23rd Nov 2009, 22:25
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Fatal reality checks are a bitch.
Amen, Codger. Amen.

But see, guys like me...I'm just a dumb ol' pilot. I don't know what could leak on an S-92 and what could not. I rely on the engineers to design the thing right. Then I rely on the regulatory agencies to verify that it's been designed right before they certify it. Then I rely on the assembly people to build it right. Finally, I rely on the mechanics to maintain it right. (Everyone, in turn, relies on me to fly it right.) That's a whole lot of relying going on.

But I'll say this: I've worked on enough cars and motorcycles in my life to know...to KNOW without a doubt...that any accessory that is bolted to an engine (or in this case a transmission) can leak at the parting surface. And anyone who's ever had the waterpump in their car fail knows that fluid can leak out around a shaft. For the latter, the analogy I'm thinking of is where the tail rotor driveshaft goes into the transmission. Is it impossible for oil to leak out there (although it must be said that this hasn't happened yet on an S-92)? Or is it just "highly unlikely given the current state of seal technology and our general design?"

Apparently, SAC told the FAA that the oil cooler and the lines to it were the only places that transmission oil could leak out of, and the FAA concurred.

The question has been asked, and was glossed-over. But it's a good one: In light of all of the above, how does the S-92 still maintain its airworthiness certificate? Why has it not been revoked?
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Old 23rd Nov 2009, 23:26
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FH1100

Nothings impossible. It's those highly improbable glitches that bite you on the butt at the worst possible times that prove that the "impossible" does happen. I'm not an engineer either but fortunately or otherwise, have gotten my mitts under plenty of cowlings over the years. There's been more than a couple of times when the impossible or highly improbable stared back at me and with a hand over my heart I've been very thankful that I saw what I did at zero AGL rather than dealing with the consequences at a higher elevation.
If something can shake loose then you lock wire it down. If something can leak then there are more colours of "goop " (technical term) that get placed between the 2 surfaces so that they can't leak.
I don't know why the CofA hasn't been pulled or if it should be pulled... But if you think that any manufacturer of aircraft puts stuff out there for us to drive knowing that there's something in there that will kill us then that's a whole other deal. I've talked with a few engineers and killing us is 180 degrees from what I picked up during those conversations.
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Old 24th Nov 2009, 00:11
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Offshore operations have changed in the last 20 years - commercial manufacturers will only react to market demand (no demand, no change) - the oil companies have to play a bigger role in making sure manufacturers keep up as they go further and further offshore in hostile environments.
Madrock, well said, we need the oil companies to push this technology forward and get away from minimum certification standards. I have a few simple but effective design ideas such as dual-redundancy MRGB pressure sensors and lube oil temperature versus casing temperature condition-based monitoring to detect early deterioration of vespel spline pumps to name but a few, but will leave that to the experts who no doubt are re-designing the MRGB for the CH-148 and maybe will utilise some of that advanced design for the S-92b.

As for 2-hour flights using aux fuel tanks and lack of alternates in the Grand Banks, we may have to also work on improving from the current SS6 capability, or start placing tighter limits of helo ops over here e.g. we've already lost night-time flying to fixed platforms (of which there is currently only one) I believe due to tightening of visibility limits.

Safe Flying

Max
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