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

[squib66]

You would think Sikorsky would have been really focused on all the ways oil could be lost, especially the appendages, like the filter among others.

[riff_raff]

"You would think Sikorsky would have been really focused on all the ways oil could be lost, especially the appendages, like the filter among others"

squib66,

The problem is not just with Sikorsky, it happens at Rolls-Royce too. Structural failure in an oil system component is apparently the root cause of the catastrophic uncontained turbine failure on the Qantas A380's Trent 900 engine.

riff_raff

[squib66]

squib66,

The problem is not just with Sikorsky, it happens at Rolls-Royce too. Structural failure in an oil system component is apparently the root cause of the catastrophic uncontained turbine failure on the Qantas A380's Trent 900 engine.

riff_raff

At least RR's response to a non-fatal accident with an Australian aircraft was quicker than Sikorsky's.:uhoh:

I've been shown some notes from the 2008 S-92 Operator's conference (that came after the Brrome event). There was apparently no mention of that serious incident directly but that there had been multiple stud failiures at that time. Is that really true?

Below are the (second-hand) notes from that conference. Most of the effort seems to be to solve the problems Shell had in Brunei.


A dedicated team has been appointed to resolve main gearbox issues:

New chip detectors are to be wired separately from high oil temp warning.
Transmission testing is being conducted with a transmission position at various attitudes rather than the traditional flat plane.
Oil filter housing studs which have been failing are to be replaced with steel studs.
Main gearbox Vespel spline issues are still NOT resolved. Two new design concepts to be released for test.
Transmission oil pump check valves are to be removed to lower gearbox oil temperature when a Vespel spline fails.
Adding a “main gear box oil pump” caution to cockpit enunciator panel
Does anyone know where S-92 MGB s/n 173-00040 is now? Its just that was run without oil for 2 mins less that the Cougar gearbox and then put back into service.

[zalt]

Broome was pretty much low profile compared to Brunei it seems.

[poppahymen]

Does anyone know where S-92 MGB s/n 173-00040 is now? Its just that was run without oil for 2 mins less that the Cougar gearbox and then put back into service. Hi Squib66 that’s what I was wondering back in post no 618. The attitude at the time (Pre Cougar) could well have been, “No worries mate these girls can run for 1/2 hr without oil"
This appeared to be a common misconception at the time. Still its probably been thru OH by now.

Take care everybody and safe flying in 2011.

[zalt]

squib

Having done some checking, it is ironic that the whistleblower is a guy who successfully had a discipline charge aginst him overturned by a federal review board. His alleged 'crime' - working late in the office!

From what is published we can't be certain but it is highly likely that a proportion of the ADs relate to Sikorsky products. Certainly the FAA found that EASA beat them to a couple of EADs on the S-92A after the accident when the Europeans made it clear they were not prepared to keep waiting for the FAA.

The fact it goes back 7 years is of interest. That was the time the S-92 was certified.

It was also the time that the Rotorcraft Directorate, for geographic reasons, were in charge of the Eclipse fixed wing certification. FAA had to rush through a special investigation on that in 2008 after congress got interested in the obvious failings. Oronically that happened about the same time as they SHOULD have been focused on Broome.

FAA employees raised concerns about Eclipse certification: AINonline (http://www.ainonline.com/ain-and-ainalerts/aviation-international-news/single-publication-story/browse/0/article/faa-employees-raised-concerns-about-eclipse-certification-9902/?no_cache=1&tx_ttnews%5Bstory_pointer%5D=1&tx_ttnews%5Bmode%5D=1)

AOPA Online: FAA, Congress revisit Eclipse 500 certification (http://www.aopa.org/aircraft/articles/2008/080820eclipse.html)

Press Release – FAA Agrees with Eclipse Certification Review Recommendations (http://www.faa.gov/news/press_releases/news_story.cfm?newsId=10287)


poppahymen

Very little has been said by CHC about the Broome incident either.

[riff_raff]

poppahymen,

While I can't speak specifically about the main gearbox in question, in general, anytime a main gearbox is run under loss of lube conditions it should be taken out of service and overhauled. Critical components like gears, sprags and bearings will likely need to be replaced.

Gearbox components like gears and bearings are designed to sustain 30 minutes of operation under loss of lube conditions without structural failure. But that does not mean they are fit for service after just a few minutes of operation with loss of lube. Gears can sustain scoring damage with less than a minute of loaded operation with inadequate lubrication.

riff_raff

[212man]

Gearbox components like gears and bearings are designed to sustain 30 minutes of operation under loss of lube conditions without structural failureDid I just read that comment (in the context of this thread,) or am I dreaming?

[Outwest]

Quote:
Gearbox components like gears and bearings are designed to sustain 30 minutes of operation under loss of lube conditions without structural failure
Did I just read that comment (in the context of this thread,) or am I dreaming?


It's not the first time he has made this ridiculous statement.


http://www.pprune.org/rotorheads/365720-helicopter-crash-off-coast-newfoundland-18-aboard-25.html

[Canadian Rotorhead]

Another case of "though shall not drink and post"

:ugh:

[riff_raff]

212man,

It would have been helpful if you would have read the entire post. Apparently, you missed the very first sentence: "While I can't speak specifically about the main gearbox in question....". I assumed everyone understandsthat the S-92 MRGB does not have a 30 min run dry capability.

My post was addressed to poppahymen's comments about an MRGB that had operated with loss of lube, and then (apparently) been kept in service. I tried to explain that this is something that is normally not done with any MRGB, even those gearboxes with a qualified run dry capability. I also gave an explanation of how even an MRGB with a run dry capability will sustain some damage when operated under loss of lube conditions, and thus must be immediately overhauled. I was speaking in general terms and describing the majority of MRGB designs that have a run dry capability, and not the S-92 gearbox in particular.

To fully understand the failure of the S-92 MRGB, it should be helpful to have some background on how any MRGB achieves a run dry capability, and what are some of the issues involved.

You can take it or leave it.

riff_raff

[212man]

Rif,
I did read it fully and accept the generic information you describe. My interpretation of your opening statement was that you couldn't comment on the state of the MRGB removed from the Broome aircraft i.e. The specific MRGB that people were asking about. In relation to that question, I don't see how it can be in service anymore as it was a 'Phase 1' gearbox and I believe all aircraft now have 'Phase 2' boxes.

[dascanio]

Riff,
I completely agree with your technical explanation.
A run dry condition is an Emergency for the gearbox, and after this,
the transmission is not intended to be serviceable again. As a
matter of fact, dry run test (cfr. AC29.927) requires only that the transmission can still ROTATE freely at the end of the 30 min test, to verify you have no seizures, and that rotor can stiil be driven (ie, the pilot can still perform a controlled landing or ditch the HC)
as far as the transmision is concerned, it is likely to find gear heavy scoring, heavy oveheating of bearings and even casings,leading to several parts
deplacement or even mgb scrap.

[zalt]

dascanio - welcome. The thing with the S-92A, despite being hailed as a breakthrough in aviation safety by its makers, was NOT tested (at least successfully!) 'run-dry' as other modern helicopters.

If it had been, perhaps this thread would have died out by Easter 2009 with congratulations to the crew for just landing onshore in time instead of an autopsy on the deaths of 17 of the 18 POB.

The S-92A was tested with only a PARTIAL loss of lubrication ASSUMING that the leak could be stopped by isolating the oil cooler. Something that certain posters here were very reluctant to admit prior to the Cougar accident.

Sikorsky's flawed design logic was based, at their own admission, on the ASSUMPTION that a leak anywhere else from the oil cooler was 'extremely remote' (despite the fact it happened once BEFORE Cougar and on other types including the Sikorsky ones...).

This is covered extensively in this thread and I'm sure you will find the story here both fascinating and shocking.

212man

Technically is it not the case that the Phase 1 and Phase 2 'MGB' only differ in CASING design and the dynamics inside the casing are the same?

Are you really implying the gears are thrown away, irrespective of time since new, when changing casing?

[The Sultan]

Riff

I understood what you were saying. I know some transmission designs that after the 30 minutes are up are started up again to see how long they last.

212man

As your incident was not a total loss of lube (still had 5 PSI?) why did you not hop it over to the nearby airfield? I think this was the basis of the Sikorsky draft what to do. With what you know now would you do it or park it again?

The Sultan

[maxwelg2]

Question, when will someone officially reveal this wonderful phase 3 MRGB design and what it will address? Feet cracking and run-dry capability? I don't see anything on the manufacturer's website, surprise surprise...

Was phase 1 and 2 designs not only addressing the mounting feet crack issue due to the press-fit bushings and insufficient housing thickness, plus the addition of the 6-stud filter housing arrangement?

212man, correct me if I'm wrong, but was your MRGB issue not down to an incorrect dipstick and overfilled MRGB lube oil system causing input module cooking and subsequent oil loss? You quite rightly shut down and waited for the unfit machine to be towed away for repair.

The latest reported high vibe incident in the Grand Banks has been covered with a veil of secrecy, no CADORS, not even any rumours on this forum. Not the best way to instill confidence in this helo, I for one will be asking Cougar directly next time I have to fly in the S92 as will many other PAX in NL. I'm quite sure the offshore frequent flyers have more information already, but we tend to keep that in-house, mainly to prevent mis-information, an all too common issue these days.

Just when I thought we were moving forward, silence is definitely not golden. Here's hoping things will change soon for the better. Explaining all the facts, warts and all, is the only way we will progress these issues and keep everybody on the same page. The latest media update attempts by C-NLOPB is unsuccessful IMHO, must do better boys.

Safe flying

Max

[zalt]

maxwelg2

I'm pretty confident that Phase 3 is mainly improved feet with no greater resistance to damage after an oil loss.

You might also want to ask Cougar if and when they have fitted the (optional) vacuum pressure switch, introduced late last year following the Shell Brunei incidents in early 2008, that was meant to give confidence to fly on with just 5psi (and smoke in the cockpit too!).

towed away for repair = underslung under an Erickson Aircrane helicopter!

I agree we can see communication after this event as another failed attempt to build confidence in the S-92A

[212man]

why did you not hop it over to the nearby airfield?

Mmm, it had something to do with the EICAS displaying MGB OIL PRESS, MGB OIL HOT, INPUT 1 CHIP, ACC 1 CHIP, ACC 2 CHIP, CHIP SYS FAULT, AC GEN 1 FAIL, The oil pressure dropping from the yellow band into the red range, and the MGB oil temperature scale disappearing once it reached it's limit. Oh, and the sensation of being in a welding shop - acrid hot metal smell plus a cabin full of white smoke. If I'd been over water I'd have ditched about 2 minutes sooner than I actually landed.

In answer to your other question, if the same thing happened to me again the indications would be different - the CHIP cautions would now say HOT and the temperature would continue to indicate. There is also a revised drill to bring the throttle back of the input module thats churning, which should reduce the heating significantly. So, probably I would continue further than I (we) did.

[zalt]

The TSB will be releasing their report into the Cougar crash on 9th February with a press conference in St Johns.

Commissioner Wells and his team start preparing for Phase 2 of their hearings, which commence after the TSB report is available, on 17th January.

[squib66]

Thanks for that. Will it be webcast too?

[zalt]

Yes there will be a live webcast by TSB and Rogers will probably interrupt the afternoon's local TV broadcast. I will update later with the details.

[SansAnhedral]

Was phase 1 and 2 designs not only addressing the mounting feet crack issue due to the press-fit bushings and insufficient housing thickness, plus the addition of the 6-stud filter housing arrangement?

The bushing press fit as an issue was a red herring.

There will be no ALS or major lube system changes before the IDMGB is fielded (who knows when) for CH148 and then possibly rolled out to the S92A fleet.

[ttt_mtt]

what is the difference between LAND AS SOON AS POSSIBLE - LAND IMMEDIATELY if you are off-shore

i did not understand this side of emergency

[Sven Sixtoo]

Arriving slightly cold but

Land Immediately

Land at once, even if it means (for instance) ditching or landing in trees. The consequences of continued flight are likely to be more dangerous than an emergency landing in a situation ordinarily not considered suitable.

Land ASAP

Land at the first site that presents a safe but unhurried opportunity. Flight should not be continued beyond the point where the aircraft can be evacuated direct to a place of safety.

Sven

[ttt_mtt]

So if we are off-shore

should we continue to coast if emergency tell us LASAP or should we land to sea safely

[Sven Sixtoo]

In the world I've inhabited

LASAP = go for the nearest deck or point of land.

Ditch = only if you reach the point in the checklist where it says LAND IMMEDIATELY

But I'm quoting a military philosophy. Civ standards may be different.

Sven

[zalt]

$2.4 million is being spent to upgrade the HUET facility in St Johns.

Offshore training centre gets $2.4 million for new equipment - Local - News - The Telegram (http://www.thetelegram.com/News/Local/2011-01-24/article-2166128/Offshore-training-centre-gets-24-million-for-new-equipment/1)

[[email protected]]

All well and good but you have to survive the impact in order to use your huet skills.

[maxwelg2]

Can't remember the last time I did a HUET with a wave machine, think it was 1991 in Aberdeen.

One metre wave machine seems a bit low but I'm assuming it's for safety reasons, then again we're not really simulating actual conditions or do we reduce SS limits? Same applies with current HUEBA training, this needs to change to make the training more realistic.

On a positive note I still see this latest announcement as an improvement on where we are today, if anything it will most likely highlight PAX fitness as another safety issue on top of the "bouyant boot" suits we're currently using...

Safe flying

Max

[fijdor]

Taken from the B212 FM.

JD


3-2. DEFINITIONS
Following terms indicate degree of urgency in
landing helicopter.

LAND AS SOON AS POSSIBLE — Land
without delay at nearest suitable area (i.e.,
open field) at which a safe approach and
landing is reasonably assured.

LAND AS SOON AS PRACTICAL — Duration of
flight and landing site are at discretion of pilot.
Extended flight beyond nearest approved
landing area is not recommended.

[S92mech]

This is from the S-92 RFM

Land immediately — Continued flight may not be possible. Ditching or landing in hazardous terrain is preferable to continuing flight.

Land as soon as possible — Land at the nearest site where a safe landing can be accomplished.

Land as soon as practical — Extended flight is not recommended. Landing site and duration of flight are at the pilot’s discretion.

[ttt_mtt]

if an emergency procedure says to LASAP before Land/Ditch we should not wait for the last signal for Ditching over sea quite far away to shore.

Because still we have a chance for a safe landing why should we wait for to Ditch(which not ensure us a safe approach or controllable helo)

for example

can you control a 212 in a dual hydraulic emergency

so will you go on to fly with a hydraulic or make safe landing to sea

[zalt]

Helicopter designers need to understand that Land Immediately does not automatically mean passengers and crew are protected if that results in, say, a ditching.

Committee hears tale of belated rescue - Local - News - The Telegram (http://www.thetelegram.com/News/Local/2011-02-02/article-2191482/Committee-hears-tale-of-belated-rescue/1)

[212man]

Zalt,
I think they do understand that which is why the requirement is only stipulated for extreme cases. Ditching and losing half the pax and crew is a really bad thing, however staying airborne and having a structural failure because you are on fire, or having the rotor stop as the MGB seizes, is probably going to result in a 100% loss. What would you recomend if writing the checklist?

[SASless]

Land Immediately.....what is ambiguous about that?

Ditch.....what is the "time" element of that directive? Immediately....delay as needed to organize SAR, divert to nearest assistance (boat, vessel, rig, point of land) or make your call and confirm someone knows your location, intentions, and numbers of persons aboard?

212man raises a good question....it depends upon how you feel about gambling with people's lives! One way you kill some.....the other way you may not kill any....or kill everyone. If you decide using probability....you continue on and roll the dice on an all or nothing wager. If you decide rationally....one could decide to risk as few as possible.

The other question that does not get argued as it should....is when do you stop flying due to the hazards beneath you that make landing out/ditching such a serious gamble? Are we ignoring the patently obivious by putting ourselves in that position? Should we operate in sea states that exceed the certification of the emergency flotation? Should we operate in temperatures (ambient and water) that present a risk of death that exceeds the SAR response time factored for successfully locating and rescuing from an in-water situation?

Get a grip on those questions then talk to me about equipment, training, physical standards, and the rest.

I don't want to hear about "economical issues, we cannot do business if we don't......and that response. Let's put lives first and economics last. Last time I checked we are not fighting a war but rather are in the oil production business. What price/value/worth do we put on human life in this business?

[SASless]

Toys firmly tossed!

Nick is anything but ambiguous. He is a well known long time Professional with a great reputation and proven ability.

Sox.... pose your questions in a manner that seeks information or begs a professional response would you? Save the personal attacks for Facebook.

Nick....slamming the door leaves the rest of us without a way to understand the issues. Reminding, in great detail, how the testiing was done would be the way to move this discussion along in a proper manner.

Throw the facts out and clear the air (once again I know....) and put Sox's allegations to rest. Ignore him as you wish....but remember the rest of us who appreciate your input here at PPrune.

[Brian Abraham]

The other question that does not get argued as it should....is when do you stop flying due to the hazards beneath you that make landing out/ditching such a serious gamble? Are we ignoring the patently obivious by putting ourselves in that position? Should we operate in sea states that exceed the certification of the emergency flotation?SAS raises a very good point that I've oft thought about. How does one go about doing the land immediately thing when flying on top of a fog layer in which the viz is zilch, dead calm water, maybe at night as well. Something you train for? Who of the crew does what in such an event? Mechanics of carrying it out?

So much of what is done in the oil industry would not meet the standards to which airlines operate. Wonder if "land immediately" features in airline checklists.

[riff_raff]

Maybe NickLappos can answer a question for me regarding the design of the S-92 MRGB lube oil filter housing. I'm not a transmission design expert, but one thing I do know is that with a single path system or component that is flight critical (like the lube oil filter housing), it should be designed with fault tolerance in all aspects. That would include the fastening system holding it in place.

Looking at the photo linked below, it would appear that even though proper fault tolerant design practice was followed regarding using multiple fasteners with dual locking features, the spacing and position of the fasteners may have been deficient. With only three widely spaced fasteners holding that filter housing in place, it appears as though the failure of just one fastener, combined with the force created by oil pressure acting against the large surface area of the filter housing, would be more than enough to dislodge the housing. In other words, this housing design does not appear to have the level of fault tolerance that would normally be required of a flight critical component. This type of flange failure is not unknown, and is something that would be checked for in a thorough FMEA.

Do you know if the filter housing was part of a critical items list? And if so, was this failure mode considered in the FMEA?

Thanks in advance for any insight you might be able to provide. And I apologize if this question was answered in an earlier post, but there's just too many to go back through.

http://www.flightglobal.com/assets/getAsset.aspx?ItemID=29667

riff_raff

[NickLappos]

Sasless, were I to post the PM that sox6 sent me, you would be very angry with him. I don't deal with assholes very well.

Riff_raff,
Your observations are well pointed at an important issue. With ongoing litigation, it is unwise for me to broadcast an answer. Pls PM me, if you will.
Thanks
Nick

[industry insider]

The new MGB housings have a 6 modified stud attachment to the MGB housing as well as a 6 secondary stud attacment for bowl removal. The attachment to the MGB housing itself never needs to be removed. I can post a picture if you wish.

[js0987]

Brian,

To your question about landing in fog or 0/0 conditions; it is something that is often done in the simulator. Its a matter of coordinating the deceleration and descent so as to arrive at the surface with as little forward airspeed and as slow a rate of descent as possible. If you don't get the big red screen, you made it.

[SASless]

How about putting in a Sea State 6, wind blowing about 45 knots, OAT of -10, and water temp of say....+5.....assume no one gets into the raft, and SAR response time of one hour to the scene, 15 minute search to the first survivor....and 14 people in the water.....at night!

How does that play out?

[FH1100 Pilot]

I hate to jump in on this, but I have to kind of back up what Sox6 says about N. Lappos and ambiguity.

I remember reading Nick's post - the glowing report about the testing SAC did on the S-92 transmission. We can dig them up and cut-and-paste them if necessary. I remember being impressed with the numbers- of how long it ran without oil. And "without oil" was implied (by Nick) and assumed (by most of us). I'll bet most of us did not completely grasp the nature of that goofy oil cooler bypass thing - that the successful use of it was dependant upon the pilots detecting a leak in the cooler lines and doing something about it before all the juice was pumped overboard.

Flash forward. We know now that "without oil" was not the case at all. We know now that all Sikorsky did was cause (or simulate) a leak in one of the lines to the external oil cooler, and then isolate that cooler and keep on truckin', as they say.

So yes, Sox6 is right: In that regard Nick was being a little ambiguous about that test because he did not mention that Sikorsky knew that without any oil the transmission wouldn't last 10 minutes. Which was, tragically, proven in the field at a later date.

But wait. Hang on. We also know that the rules are ambiguous, aren't they? Disregarding that awkward "extremely remote" wording, we know that the rules do not call for a complete loss of all transmission oil and then 30 minutes of continued operation. Nope, the particular rule only references "a" loss of lubricant, and it doesn't specify how much lubricant must be or can be lost. There's some wriggle-room in the interpretation, and SAC used it every millimeter of it.

After Cougar, Nick was in a horrible, unenviable position (and likely still is, depending on what litigation comes out of that crash). At the time of certification, he probably really, really, really, really believed that those oil cooler lines were the "only" potential source of a leak. Hey, nobody's perfect. So even if Nick was not being totally clear or forthcoming, are we to assume he was being deliberately ambiguous or worse, dishonest? No. And I think it would be unfair to him for us to assume so.

Now Sikorsky, on the other hand...

Well... that's for the courts to decide. The real courts. Here on the internet, the PPRUNE court of popular opinion has ruled that Sikorsky fudged on that "extremely remote" stuff, and the FAA went right along with them.

[SASless]

Or.....did the FAA write a certification requirement that used the "extremely remote" standard and Sikorsky comply with that requirement?

I would suggest the industry learned a lesson out of this tragedy....at least we hope we did.

The real lesson learned is simply....Helicopters are different than airplanes.

Helicopters rely upon "transmissions" for more than mere propulsion....they are also "flight controls"....and "extremely remote" being an allowable failure is fatally flawed logic.


Finally.....when the Checklist clearly stated:
MGB Oil Pressure < 5psi.....Land Immediately!

Does it matter why one does not comply with the Checklist? Sikorsky correctly stated the action that SHOULD have been taken. It was right there in Black and White printed on the Checklist.

I would love to read the transcript of the radio exchange between the Flight Crew and their OPs while they were turning back and descending to a lower level and staying at cruise power upon leveling off. That would probably explain why they did what they did.

Anyone have a transcript of that handy?

[What Limits]

But in a risk management context, extremely remote is probably the lowest level of likelihood above zero.

Can we really afford to buy or operate aircraft that have zero likelihood of something going wrong?

Even flight critical components have a mean time between failures.

I do not wish to get into the blame game, but what we should be focusing on is the decision making by all the stakeholders in a Threat and Error Management context.

[squib66]

FH1100 Pilot - good analysis!

It is worth remembering that in some juristictions there would be more that just claims for damages. In the UK there is now a crime of corporate manslaughter, brought in to make sure big companies are accountable for their actions.

After the terrible Nimrod crash in Afganistan, which killed 3 people less that Cougar 491, ten people were publically named and shamed for failures in connection with that accident by a special inquiry. The most senior was accused of:
...a "fundamental failure of leadership" ..and that... he failed, in truth, to make safety his first priority." All ten were facing diciplinary action and possible criminal or civil charges.

That inquiry commented that:


A safety review... was a "lamentable job" which failed to identify "key dangers", he said. "Its production is a story of incompetence, complacency and cynicism. The best opportunity to prevent the accident...was tragically lost".


One wonders what could be said about the FMEA for the S-92 and the analysis that falsely concluded the critical failures that occurred would be 'extremely remote' (and in practice were anything but). One also wonders who will stand up and take responsability for the short comings in teh design

Let us also not forget that the component that failed was a simple threaded stud, that was static and not heavily loaded. If the designers failed on such simple and basic components, one must seriously question other elements of the design. In fact the studs should not have even been critical components, it was only a poor design that made them critical!

Those who are critical of the pilots for not ditching into a choppy and freezing ocean need to remember that a certification loop-hole was cynically used to avoid fixing a known inability to operate with a loss of lubrication. Thirty minutes operation who have resulted in a safe landing.

[HeliComparator]

we know that the rules do not call for a complete loss of all transmission oil and then 30 minutes of continued operation. Nope, the particular rule only references "a" loss of lubricant, and it doesn't specify how much lubricant must be or can be lost.

Its true that the rule is rather ambiguous, however the guidance material that went with it (AC 29-2C) is more specific. Use of the word "drained" is surely indicative of losing all the oil? Sorry for long quote below:

b. Procedures.
(1) Section 29.927(c) prescribes a test which is intended to demonstrate that
no hazardous failure or malfunction will occur in the event of a major rotor drive system lubrication failure. The lubrication failure should not impair the ability of the crew to continue safe operation of Category A rotorcraft for at least 30 minutes after perception of the failure by the flight crew. For Category B rotorcraft, safe operation under autorotative conditions should continue for at least 15 minutes. Near the completion of the lubrication failure test, an input torque should be applied for 15 seconds to simulate
a minimum power landing following autorotation. Some damage to rotor drive system components is acceptable after completion of the lubrication system testing. The lubrication system failure modes of interest are usually limited to failure of bearings, gears, splines, clutches, etc., of pressure lubricated transmissions and/or gearboxes. A bench test (transmission test rig) is commonly used to demonstrate compliance with this rule. Since this is a test of the capability of the residual oil in the transmission to provide limited lubrication, a critical entry condition for the test should be established.
The transmission lubricating oil should be drained while the transmission is operating at maximum normal speed and nominal cruise torque (reacted as appropriate at the main mast and tail rotor output quills). A vertical load should be applied at the mast, equal to the gross weight of the rotorcraft at 1g, and the lubricant should be at the maximum temperature limit. Upon illumination of the low oil pressure warning required by § 29.1305, reduce the input torque for Category A rotorcraft to the minimum torque necessary to sustain flight at the maximum gross weight and the most efficient flight conditions. To complete the test, apply an input torque to the transmission for approximately 25 seconds to simulate an autorotation. The last 10 seconds (of the 25 seconds) should be at the torque required for a minimum power landing. A successful demonstration may involve limited damage to the transmission, provided it is determined that the autorotative capabilities of the rotorcraft were not significantly impaired. For Category B rotorcraft, upon illumination of the low oil pressure warning light, reduce the input torque to simulate an autorotation and continue transmission operation for 15 minutes. To complete the test, apply an input torque to the transmission for approximately 15 seconds to simulate a minimum power landing. A successful demonstration may involve limited damage to the transmission provided it is
determined that the autorotative capabilities of the rotorcraft were not significantly impaired. If compliance with Category A requirements is demonstrated, Category B requirements will have been met.

So its my contention that the only way it achieved certification was through the "extremely remote" bit.

HC

[heliski22]

From Sasless

Finally.....when the Checklist clearly stated:
MGB Oil Pressure < 5psi.....Land Immediately!

From Squib66

Those who are critical of the pilots for not ditching into a choppy and freezing ocean need to remember that a certification loop-hole was cynically used to avoid fixing a known inability to operate with a loss of lubrication. Thirty minutes operation who have resulted in a safe landing.

Notwithstanding the validity of all the arguments back and forth and whilst acknowledging the possible influence of such a hostile environment upon flight crew trying to make the right response to a serious emergency in those circumstances, that checklist item has all the hallmarks of a corporate get-out-of-jail clause, does it not?

22

[zalt]

Heliski
Not if you consider the whole raft of other requirements to minimise such failures, apply crtical parts control processes, respond promptly to occurrences and so on.

[Outwest]

More on this tragic, preventable accident here:

Problems seen before fatal N.L. chopper crash: investigator - CTV News (http://www.ctv.ca/CTVNews/Canada/20110206/nl-fatal-sikorsky-crash-report-110206/)

Thanks Bill for trying, too bad it fell on deaf ears......

I can give SAC some leeway in how it handled the initial certification re the "extremely remote" clause...... no one is perfect, we all make mistakes. However, after the Broome incident clearly showed the error of this rational, I hold SAC/FAA 100% accountable for the Cougar accident.

[zalt]

Interesting article.

Can anyone explain this?:

On Oct. 8, 2008, the company issued an advisory calling for "enhanced inspections" of the oil filter bowl studs and threads, and on Nov. 5 made changes to the maintenance manual

Paul Jackson, a spokesman for Sikorsky, said the changes "would have allowed customers to detect discrepancies in the stud threads and thus prevent a fatigue fracture of the stud."



AFAIK the MM change simply banned reusing the nuts.

Nice to see ex TC officials understand the problem of the indaequate certification (even if Broome was not a crash):

Alan Stewart, a former Transport Canada employee who oversaw the Canadian certification of the S-92, said after the Australian crash, the assumptions of the original certification for "30-minute run dry" were no longer valid.

"The whole premise that the (main gearbox) case could not break and leak out every drop of oil had been proven wrong before the Newfoundland crash. That's the point where the certification assumptions were proven wrong," said Stewart, who now works in the private sector.



and

Shawn Coyle, a former employee of Transport Canada's air worthiness division, contends regulators should have quickly ordered repairs and given clear instructions to pilots.

"It should have been weeks, at the most," he said.

Coyle, a 60-year-old test pilot, also said Transport Canada's certification system needs to improve the way it reacts to key assumptions used in certification if a failure is exposed.



Its clear Sikorsky have failed to communicate clearly, based on the experience of the TSB man who arrange the lab tests on the Broome studs:

"I still question what Sikorsky and the FAA knew (about) how close that transmission was to failure. ... That was what I was hoping to hear when I sent the email saying, 'We look forward to hearing what you find because we have these aircraft operating in Canada,' " he said in a recent telephone interview from his office in Vancouver.

"And I still haven't heard."



Of more explosive note is that the FAA claims that after Broome its:

...response was appropriate after the incident in Broome, Australia, because it, "prompted discussions among many FAA specialists about the relationship of the Broome failure to the certification basis of the aircraft."

Does his mean the FAA, while failing to issue an AD before Cougar 491, had to have a debate over wether the aircraft actual meets it certification basis?

[Brian Abraham]

Use of the word "drained" is surely indicative of losing all the oil?HC, this is another illustration of how do you interpret AC 29-2C.

Since this is a test of the capability of the residual oil in the transmission to provide limited lubrication, a critical entry condition for the test should be established.The question seems to be, what constitutes "residual oil"? That remaining after the crew have activated the switch? Was the point of switch activation considered the "critical entry condition"? Questions, but no answers.

[maxwelg2]

How about putting in a Sea State 6, wind blowing about 45 knots, OAT of -10, and water temp of say....+5.....assume no one gets into the raft, and SAR response time of one hour to the scene, 15 minute search to the first survivor....and 14 people in the water.....at night!

How does that play out?

Good point SASless, IMO SS6 floats don't give operators the divine right to place pilots and PAX at unacceptable risk levels by flying in such conditions. The downside over here in NL is that there are very few "good" flying days, especially at this time of year.

My last couple of SLF trips in the Grand Banks have been right on the flying limits, sometimes after 3 days hanging around the heliport waiting for a "window". Vessel transfer is not really an option with our current season and big oil still wants that black stuff out of the ground and sent to market. The NL economy would be crippled without it as well, so we all carry on accepting the risks, just the same as the fisherman who goes out at 3 in the morning for days at a time with an under-funded SAR coverage. That's just the hard facts right now up here on the Rock.

Although it's nice to experience systems such as the RIPS working well I do ask myself these days what are our odds of survival if for some god-forsaken reason we have to go into the drink? Is our survival equipment and training really up to snuff? Will a 1-metre wave machine in a pool really prepare us for a full-blown capsize in 3-4 metre seas, I don't think so.

Should the A/C be more robust with run-dry capability, yes of course, well then when are we going to get that and what will it take before SAC will provide this capability in the S92?

Going forward we have to learn from mistakes, and IMHO SAC/FAA are 100% at fault here for 491 via a myriad of reasons and hopefully one day soon they will be found guilty and held accountable for their grave mistakes and do their utmost to make amends. We owe that not just to those we have lost but to all of us who still work in this industry, be it engineer, pilot or PAX.

Safe flying

Max

[HeliComparator]

The question seems to be, what constitutes "residual oil"? That remaining after the crew have activated the switch? Was the point of switch activation considered the "critical entry condition"? Questions, but no answers.

Brian, I take your point. To my mind residual oil is what is left clinging to gears, bearings, shafts etc and since there is no mention of discontinuing the drain, it would seem to be the intention to drain all the free oil out. But as you say, that is just my interpretation and demonstrates the difficulty of using the written word to communicate unambiguously (something lawyers have been cashing in on since the law was invented!).

HC

[HeliComparator]

Max, not being up to speed on things Canadian, does TC blindly accept FAA certification, or does someone in TC look at the certification data before accepting it? (just wondering if you can add TC to your list of those culpable).

I believe that there was some squeaking from EASA on the 92 certification, but in the end to refuse certification of something endorsed by FAA was politically too difficult.

HC

[SASless]

Max.....it is not the Operators alone at fault. The Oil Companies are the ones that set the standards for their Operation....the Helicopter companies are held hostage to those standards to a great degree.

I appreciate the conditions that exist there....just as the Alaska operators face when working out of Dead Horse and to the Chukchi. We cannot change the climate, weather, or terrain. We just have to be willing to admit to ourselves the actual risk and do everything possible to mitigate that risk to a tolerable level. The 64 Dollar Question is what is the minimum tolerable level?

[RVDT]

HC,

Most likely -

AGREEMENT BETWEEN THE GOVERNMENT OF CANADA
AND
THE GOVERNMENT OF THE UNITED STATES OF AMERICA
FOR
PROMOTION OF AVIATION SAFETY (http://www.tc.gc.ca/eng/civilaviation/standards/int-baa-usa-2000-3676.htm)

In order to refine the type certification process and to gain maximum benefit from existing bilateral airworthiness agreements or other similar agreements, greater reliance is to be placed on the acceptance of foreign Type Certificates. Hitherto, with few exceptions, TCCA had accepted, without review, all normal, utility and aerobatic aircraft from the United States, including gliders and balloons on the basis of the Federal Aviation Administration type certification. By contrast, transport, commuter and restricted category aircraft designed and manufactured in the United States were subject to a validation process between 1970 and 1985, which was replaced by a familiarization process in 1985 as a result of a revised Canada/US Bilateral Airworthiness Agreement.

[SASless]

I cannot but wait to see the UK CAA sign on to such a thing....and do so without twisting things up.

[RVDT]

SAS,

They already have signed on - its called EASA

[Dan Reno]

Flaws spotted months before Cougar crash

Problems with gearbox, titanium studs reported in 2008: investigator

Last Updated: Sunday, February 6, 2011 | 7:57 The Canadian Press


http://www.cbc.ca/gfx/images/news/photos/2010/01/28/nl-cougar-inspection-1103.gifA forthcoming Transportation Safety Board report is expected to focus on the gearbox of the Sikorsky aircraft involved in the fatal Cougar Helicopters crash of March 2009. (CBC) A Canadian investigator who red-flagged main gearbox problems months before a Sikorsky helicopter crashed off Newfoundland says he'll closely read a federal report on what caused the deadly accident.
The Transportation Safety Board of Canada is on Wednesday scheduled to release its final report on the March 12, 2009, crash of a Sikorsky S-92 helicopter that resulted in the deaths of 17 crew and passengers.
The board has already said that before the chopper carrying offshore oil workers plunged into the ocean, two titanium studs holding the main gearbox's oil filter broke in mid-flight.
Bill Yearwood, a veteran investigator with the TSB in British Columbia, says he'll be among the observers reading the final report on the disaster to see what the findings are on the gearbox.
He oversaw a brief TSB report completed on Aug. 29, 2008, almost six months before the Newfoundland crash, that concluded there were problems with the oil lubrication system on the gearbox and the titanium studs.
He forwarded his results to the Federal Aviation Administration, the U.S. agency that originally certified the aircraft, saying he hoped to hear what a deeper probe would find.
"I still question what Sikorsky and the FAA knew [about] how close that transmission was to failure. … That was what I was hoping to hear when I sent the email saying, 'We look forward to hearing what you find because we have these aircraft operating in Canada,' " he said in a recent telephone interview from his office in Vancouver.
"And I still haven't heard."
Investigation overseen in 2008

Yearwood hasn't been involved in the investigation of the Cougar Flight 491 crash.
However, he hired an engineering team six months before the crash to look at why several mounting bolts holding an oil filter assembly broke and oil leaked out in 2008 during a flight carrying Australian offshore oil workers. His office was asked to look into the Australian incident by CHC Helicopter of Richmond, B.C., which operated the S-92, as the firm attempted to understand why the studs had failed.
They found the fracture of the studs was caused by problems with the oil filter system rather than a mechanic's installation error, said Yearwood.
In a memo released by the TSB, Yearwood wrote: "There appears to be several unresolved issues with the oil system ... on this particular aircraft. It seems likely that these issues are related to the stud failures."
Yearwood said he's wondered what follow-up occurred.
"All we know is they got the information that they should look further, but whether they did I don't know. And I've been anxious to see if in our (TSB) investigation they got down to the nitty-gritty and said, 'What did you learn when you looked at that first transmission?' "
No obligation to share documents

A spokesman for the U.S. agency says that the memo was received, and the agency wrote back to the investigator to thank him for his work.
Les Dorr said the agency didn't send any follow-up research it did to Yearwood because it wasn't under any obligation to do so under international agreements.
In an email, he said the agency's response was appropriate after the incident in Broome, Australia, because it, "prompted discussions among many FAA specialists about the relationship of the Broome failure to the certification basis of the aircraft."
Sikorsky issued an alert service bulletin six seeks before the Cougar crash telling S-92 operators to replace the titanium studs with steel parts. The Jan. 28, 2009, bulletin made compliance essential after one year or 1,250 flight hours.
The company also said in an email on Friday that it evaluated the studs "immediately after receipt" of Yearwood's memo.
On Oct. 8, 2008, the company issued an advisory calling for "enhanced inspections" of the oil filter bowl studs and threads, and on Nov. 5 made changes to the maintenance manual
Paul Jackson, a spokesman for Sikorsky, said the changes "would have allowed customers to detect discrepancies in the stud threads and thus prevent a fatigue fracture of the stud."
Significance not quickly grasped

At the time, Yearwood said he didn't realize the significance of what he touched on.
After the Cougar crash off Newfoundland, the ability of the gearbox to operate for 30 minutes after losing oil became an issue.
A lawsuit filed this September by St. John's-based Cougar Helicopters alleges in a statement of claim that Sikorsky's "analysis was flawed" in claiming the aircraft could fly 30 minutes after losing oil from the gearbox.
The statement of claim contends the pilots of Cougar Flight 491 were attempting to fly back to land, when they reported a loss of pressure in the chopper's main gearbox about 11 minutes before plunging into the North Atlantic.
Sikorsky has not filed a statement of defence yet.
'Extremely remote'

The FAA granted Sikorsky the "30-minute" certification in 2004, basing it on an assumption that the chances of an oil leak were "extremely remote," say documents obtained from the FAA through freedom of information legislation. The agency defines "extremely remote" as only once in every 10 million flight hours."
Alan Stewart, a former Transport Canada employee who oversaw the Canadian certification of the S-92, said after the Australian crash, the assumptions of the original certification for "30-minute run dry" were no longer valid.
"The whole premise that the (main gearbox) case could not break and leak out every drop of oil had been proven wrong before the Newfoundland crash. That's the point where the certification assumptions were proven wrong," said Stewart, who now works in the private sector.
Dorr said the FAA took into account the Australian incident and started working on a fix for the gearbox studs.
"The FAA ... worked with Sikorsky to develop and qualify improved attachment hardware to reduce the likelihood of future failures," he wrote in the email.
He said there were still questions at the time about whether the incident in Australia definitely showed that the original certification assumptions were flawed.
The agency had noted, Dorr said, that the operators of the S-92 in Australia, which was CHC helicopters, had "deviated" from the usual aircraft maintenance instructions when they did previous oil filter replacements.
Dorr also said the FAA stands by its original decision to certify the gearbox.
Since the crash, two separate air worthiness directives were issued by the agency to address concerns over possible leakage from the oil filter bowl, he added.
The first directive was issued in early 2009 to require installation of the improved studs that attach the filter bowl to the gearbox. A follow-up directive was issued in 2010 that required installation of a two-piece filter bowl featuring additional, stronger bolts with significantly improved protection against maintenance errors.
Faster response needed: test pilot

Shawn Coyle, a former employee of Transport Canada's air worthiness division, contends regulators should have quickly ordered repairs and given clear instructions to pilots.
"It should have been weeks, at the most," he said.
Coyle, a 60-year-old test pilot, also said Transport Canada's certification system needs to improve the way it reacts to key assumptions used in certification if a failure is exposed.
"There doesn't seem to be any regular review with the people doing the original approvals to see the assumption made in the approval are still valid," he said in an interview.
A spokeswoman from Transport Canada would not comment on how it handled Yearwood's memo.
Maryse Durette, a spokeswoman for the agency, says in an email the matter was the FAA's responsibility and Transport Canada would wait for the original certifier to make recommendations before acting.
"When an unsafe condition that could impact the safe operation of an aircraft is identified, the state of design (in this case, the United States FAA) issues an airworthiness directive to mandate appropriate corrective action," she wrote.



Read more: CBC News - Nfld. & Labrador - Flaws spotted months before Cougar crash (http://www.cbc.ca/canada/newfoundland-labrador/story/2011/02/06/cougar-crash-tsb-advance-206.html#ixzz1DHg2KPZN)

[maxwelg2]

Max, not being up to speed on things Canadian, does TC blindly accept FAA certification, or does someone in TC look at the certification data before accepting it? (just wondering if you can add TC to your list of those culpable).

HC, in one word and IMHO...yes.

Should it be this way,again IMHO...no.

SASless, totally agree sir, my previous post was directed at Big Oil not the operator who I personally believe do the best job possible up here with the equipment available to them. It's all a question of what level of risk we all are willing to accept. The fact that I still fly and do not exercise my right to refuse work is my own personal decision and does not detract from the bigger issues currently present not just with the S92 but with helo ops globally in hostile environments. I've been in this industry for nearly 20 years now and have seen many safety improvements over the years, but there is always still room for improvement.

I'm hopeful that one day FAA & SAC will provide us with a more robust A/C but there will always be risk in relation to flying ops, especially in the Grand Banks. More robust safety equipment (survival suits), better and more realistic training will be steps in the right direction.

With the 2nd anniversary of 491 all too soon approaching I reflect back and look to see how we are now better off. For me there is still not enough forward progress on all the issues that we are currently aware of. Hopefully this will change soon.

Safe flying

Max

[Brian Abraham]

The agency had noted, Dorr said, that the operators of the S-92 in Australia, which was CHC helicopters, had "deviated" from the usual aircraft maintenance instructions when they did previous oil filter replacements.How did they "deviate"? FAA attempting to refocus the spotlight?

[SASless]

Brian lad.....look into the years old rift between the US NTSB and the FAA! The FAA are a bunch of round shouldered paper shuffling take no stand buinch of bureaucrats. The NTSB calls for changes, modifications, and the FAA twiddles their thumbs and initiate committes, reviews, studies, and call for testimony for Proposed Rule Changes. Glaciers move faster than the FAA!

[squib66]

Brian


Quote:
Use of the word "drained" is surely indicative of losing all the oil?
HC, this is another illustration of how do you interpret AC 29-2C.

Quote:
Since this is a test of the capability of the residual oil in the transmission to provide limited lubrication, a critical entry condition for the test should be established.
The question seems to be, what constitutes "residual oil"? That remaining after the crew have activated the switch? Was the point of switch activation considered the "critical entry condition"? Questions, but no answers.


But remember Sikorsky did the test like every other manufacturer has done and drained the oil, just leaving the residual oil HC mentions BUT the difference is that when that test spectacularly failed, Sikorsky only then cooked up their novel interpretation and introduced the bypas system.

[SASless]

How do you determine you have an oil leak on the 92 while in flight? How do you determine the extent of the leak once you determine a leak exists?

212man....or any of you other 92 folks care to enlighten the rest of us?

[Shawn Coyle]

maxweig2
I used to work in TC's Aircraft Certification section.

TC does not blindly accept FAA certification. There were a number of 'concern' papers raised by TC on issues related to the S-92 certification. Unfortunately, it appears that there was none raised on the loss of lubrication.

In the past, TC has been pretty good on this - the Boeing 757 thrust reverser design was changed to suit TC requirements long before the Lauda air crash (when the thrust reverser deployed in flight).

You'd have to ask TC why there wasn't such a concern paper raised on the S-92. Good luck getting any kind of sensible answer.

[squib66]

SASless

How do you determine you have an oil leak on the 92 while in flight? How do you determine the extent of the leak once you determine a leak exists?


I'm not sure if this is trick question(!), but the S-92 is fairly conventional in using an indirect indication based on oil pressure (indirect because you could theoretically lose the pump funtionality but without a loss of oil). In the case of a leak, oil pressure pretty proportional to oil quantity.

55psi is normal on S-92 with a caution light as ~35/45psi

Below 5 psi the Flight Manual calls for Land Immediately.

No that might seem straightfoward when flying an armchair, confusingly that is well down a rather wordy checklist, alongside text that may have implied other physical symptoms would also have been present and without prior clear instruction to continue to monitor the relatively small gauge.

There is no warning given at the critical 5psi level.

The last press article also hints at a so-called Sikorsky Safety Advisory that came out after Broome but before St John's that implied the Flight Manual was to be changed to eliminate certain requirements to land immediately (in the case of smoke in cabin caused by another type of gearbox failure that has occurred). EASA (and then FAA) both issued safety alerts that the proposed change discussed in that Sikorsky document had not been approved and that proposal to slacken the Flight Manual has since been dropped.

An added challenge is that if one pump fails (as has happened several times on the S-92 so far promting rapid landings) the pressure can drop to 7psi (dependent on the build standard of the oil system). Remember that 2psi delta could be the difference between flying on to a landing site and ditching into an ocean. Now think about the last oil gauge you looked at, remember how small it was and wonder how well calibrated the gauge is...

IMHO Sikorsky have been very lucky to have not had prior ditchings to the various MGB dynamic system failures. BTW is you look in the new CAA CAP800 UK safety review, S-92 features 5 times in a list of recent high-severity events due to MGB foot cracks. These might be technically unrelated failures modes but they share an element in common: the same design team.

[maxwelg2]

Hi Shawn

I wouldn't even consider asking TC, as a lowly PAX/SLF I just trust that they do their job properly and that suitable safeguard/compliance procedures are in place via adherence to the respective standards. Sadly in this case and IMHO they did not, neither did SAC.

I'll leave it to the professionals who really know their stuff to take them to court in an attempt to prevent such a similar event happening in the future. I am still hopeful that this will happen albeit not as quickly as I would like to see.

Safe flying

Max

[zalt]

SASless

The 64 Dollar Question is what is the minimum tolerable level?

Good question.

Part 29 calls for catestrophic transmission failure modes to be identified and reduced as far as technically feasible and economicaly justifiable.

If changing the studs to steel is an adequate fix as Sikorsky claim, the 64 (k or million) Dollar Question seems to have a 64 cent answer - it wasn't.

[CPjournalist]

Appreciate comments/perspectives on article. Just a note to say that I'd be interested in being contacted by S-92 pilots regarding reaction to TSB findings on Weds., after people have read relevant portions. The Halifax bureau telephone is 1-902-422-1129.

[SASless]

Squibb....it was an honest question and thank you for your response.

What I get from your answer is there is no way to know with certainty there has been a complete/near complete loss of oil and the only suggestion would be a decrease or loss of pressure which could also be due to other causes or even bogus indications.

Is that a correct assumption?

Way back during this thread I also suggested temperature sensing also relied upon having oil to accurately reflect the actual oil temperature and upon a loss of oil it would be possible to lose reliable temp indications.

As I see it....without knowing there has been a loss of oil, one would not know when to start the 30 minute countdown timer.

Am I missing something in looking at the way the oil quantity can be ascertained in flight by the pilots?

I used to have a valid 92 Checklist but lost it in a hard drive death so I cannot look back on that to refresh my recollection.

[squib66]

SASless

I'm glad I did give a flippant answer like 'when the tail rotor power is lost' then!

Yes oil temperature would become unreliable and certainly would not rise as the gears got hot if oil was not flowing over it.

As I see it....without knowing there has been a loss of oil, one would not know when to start the 30 minute countdown timer.


Ah but in the certification loss of lubrication test, the timing starts when the low oil pressure light illuminates (which depending on the setting may mean 30-50% of the oil has already been lost).

It is also worth remembering that in the test Sikorsky used to show compliance with that requirement, as well as making the assumption that the oil loss was most likely to be from the oil cooler, they also made the assumption that the crew would manually activate the oil cooler bypass in less than 10 seconds from that low pressure light being illuminated (now that is an immediate action!).

There is a checklist in this thread that HC first posted after one of the earlier oil system incidents http://www.pprune.org/6036981-post688.html

[SASless]

So....I reach up and flip said switch in the Ten Second interval required and am left assuming I have trapped some residual oil. After doing that.....would I be able to identify a continuing leak of oil and determine I need do something more drastic than I have done so far in the process?

Much earlier I posed a question about whether the displayed oil temp might even DECREASE rather than increase if there was a complete/near complete loss of oil.

Any thoughts along these lines?

[squib66]

Having rechecked the FM you have just 5s to activate the bypass in fact!

would I be able to identify a continuing leak of oil and determine I need do something more drastic than I have done so far in the process?


Only by a falling oil pressure BUT confusingly that is also a symptom of oil pump failures unrelated to oil loss that had happened 3 times prior (at least).

At the time of the Norsk incident any continuing pressure drop below 35psi was meant to trigger a pilot action to Land Immediately. Sometime after that it was relaxed to a continued drop below just 5spi.

Much earlier I posed a question about whether the displayed oil temp might even DECREASE rather than increase if there was a complete/near complete loss of oil.


I think oil temp would at best be 'unreliable' and certainly might go down if the sensor is not 'washed' by hot oil. The Flight Manual does however discuss high oil temperatures at a warning sign - something that might cause more confusion to a crew turning for shore and assessing the situation.

Hopefully the TSB have considered all this in detail. Its just a pity they did not push the issue of the MGB design after they looked at the filter housing from CHC Australia's aircraft (though ATSB did not investigate that one either).

The TSB report is out at 17:30UTC.

[Flash2001]

The Canadian Transportation Safety Board has reported.

Aviation # A09A0016

[maxwelg2]

From a quick first pass of the report main issues IMO:

PIC did not believe that MRGB lube oil was gone due to false "normal" temperature indication. Pump failure was suspect as cause of no lube oil pressure. But temperature should have increased with activation of bypass switch which was done very late. This was a key miss by the PIC IMO.

Only when T/R drive failed did they know for sure.

Sad, very very sad...here's hoping the TSB recommended changes make this scenario a thing of the past.

Safe flying

Max

[Mel Effluent]

Link here: Transportation Safety Board of Canada - AVIATION REPORTS - 2009 - A09A0016 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/A09A0016/A09A0016.asp)

[Hedge36]

They certainly didn't pull any punches on the first page.

[Canadian Rotorhead]

Transportation Safety Board of Canada - AVIATION REPORTS - 2009 - A09A0016 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/A09A0016/A09A0016.asp#tphp)

[902Jon]

Wow - that is a report. If they can get these sort of recommendations sorted in agreement with the FAA and EASA it will be very interesting.

TSB Recommendations
The Federal Aviation Administration, Transport Canada and the European Aviation Safety Agency remove the "extremely remote" provision from the rule requiring 30 minutes of safe operation following the loss of main gearbox lubricant for all newly constructed Category A transport helicopters and, after a phase-in period, for all existing ones.
The Federal Aviation Administration assess the adequacy of the 30 minute main gearbox run dry requirement for Category A transport helicopters.
Transport Canada prohibit commercial operation of Category A transport helicopters over water when the sea state will not permit safe ditching and successful evacuation.
Transport Canada require that supplemental underwater breathing apparatus be mandatory for all occupants of helicopters involved in overwater flights who are required to wear a Passenger Transportation Suit System.


I imagine that there would be a lot of days with no flying.

[[email protected]]

This seems to be the most telling statement Therefore, the Board recommends that:

The Federal Aviation Administration, Transport Canada and the European Aviation Safety Agency remove the "extremely remote" provision from the rule requiring 30 minutes of safe operation following the loss of main gearbox lubricant for all newly constructed Category A transport helicopters and, after a phase-in period, for all existing ones.

A11-01

[HeliComparator]

Thanks for the link CR. Still digesting it but it seems to be an excellent report, though it does make rather depressing reading in a number of areas. PPRuNe gets a mention, which is perhaps a first in an accident report?

HC

[SansAnhedral]

On 06 August 2002, Sikorsky carried out its initial certification loss of lubricant test by draining the MGB and using only the remaining residual oil (approximately 1.3 gallons) then continuing operation in accordance with the requirements of AC 29-2C.136 (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/A09A0016/A09A0016.asp#fn_136) The purpose of this test, outlined in the test documentation, was to demonstrate that the S-92A transmission could provide, "continued safe operation for a minimum of 30 minutes following a complete loss of lubricating oil in accordance with the requirements of FAR 29.927(c)(1)."
The MGB suffered a catastrophic failure about 11 minutes after the test was started. The root cause for the loss of drive was determined to be the complete loss of teeth from the sun gear due to excessive temperature caused by lack of lubrication.


Well there you have it. That was always the big secret, was it not?

[Aser]

depressing reading
A good report but I miss some more recommendations...

Reading the last moments of the flight was very hard for me.

Aser.

[Flash2001]

I watched the press conference. They certainly didn't pull any punches there either. I was disappointed that the talking head started yapping just after the floor was opened for questions.

[Canadian Rotorhead]

...Even harder for the friends and family here.

[mickjoebill]

Transport Canada require that supplemental underwater breathing apparatus be mandatory for all occupants of helicopters involved in overwater flights who are required to wear a Passenger Transportation Suit System.

Do they mean to make a connection between emergency breathing systems and those flights where immersion suits are worn? If so what is the connection?


Mickjoebill

[malabo]

The explanation is in the report. The connection is how long a person can hold their breath depending on the temperature of the water. If the water is cold enough to require an immersion suit, the conclusion is that they won't be able to hold their breath long enough to exit the aircraft. Hence if the water temp dictates that a suit is required, then an EUBA is logically required as well. Note the water temps were about 0C that day.

I don't think you have to worry about it in Oz with the warm water there.

[Treg]

Bass Straight in winter will get your attention...

[Vie sans frontieres]

At 1037, Cougar Rescue 61, a company S-92A equipped for search and rescue (SAR) operations, departed CYYT for the accident site, arriving at 1055. Using the helicopter's hoist, a rescue specialist recovered the sole survivor approximately 20 minutes later.

Nice work rescuing him:D but why 20 minutes after arrival? When someone is in freezing cold water, should you not be getting him out ASAP, injuries or no injuries?:confused:

[Bravo73]

Is anyone else having problems 'downloading/reading' the whole report? It only seems to want to load to section 1.5 on either of my 2 browsers.

[212man]

Did you try the refresh 'button'? That's what I did....

[industry insider]

Go to the main website and you can download a 5mb pdf version of the whole report. It is interesting if distressing reading.

[geneman]

From preliminary reading of the report, it is obvious from CVR data that the flight crew believed that there was still oil in the main gearbox.

This was a crucial factor in their deciding not to attempt a controlled ditching, with all its associated risks.

However, we are also left with the impression that there was no direct indicator of the amount of oil in the MGB, just pressure and temperature.

Obviously, if there were NO oil in the MGB, the oil temp reading was meaningless.

Can someone with knowledge of the type confirm whether or not there is an indicator of oil level in the sump of the S-92 MGB?

It would surely be a relatively simple task to design a sensor for oil level.

[SASless]

Maybe I am a complete Dullard....but why not simply require Supplemental Air Devices for all over water flights and prevent folks having to soley rely upon a single breath to escape from a submerged aircraft?

If one smacks the water with some force...gets the breath knocked out of you....as is highly likely...would not having a chance to get some air be worth its weight in Gold?

Again....it sounds like the Government wants to half ass safety requirements!

To repeat my usual rant.....just what is a human life worth?

[Bravo73]

Did you try the refresh 'button'? That's what I did....

Repeatedly! ;)

Go to the main website and you can download a 5mb pdf version of the whole report. It is interesting if distressing reading.

Thanks.

If anyone else is having the same issue, the pdf download link is here (http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/a09a0016/a09a0016.pdf).

[squib66]

Moderators: for continuity and simplicity can you please consider merging this with the thread that has been running for 23 months already on this accident?

[squib66]

geneman

Level sensors would be very difficult in a helicopter MGB. Flow sensors are easier but more difficult to interpret. After 6 years Sikorsky are introducing these to detect if a pump has failed.

It would be better to introduce an emergency lube system. I had hoped this would be one of the actions Sikorsky were taking.

SASless

It looks like our recent discussion on oil temperature has been validated. Odd TC asked for oil temperature in the FM.

SansA

Yes. It is now clear that the bypass system and the 'extremely remote' loophole were last minute afterthoughts - as some of us here have said - and this explains the delayed EASA certification.

HC

I noticed the social media comments. Some people can at least feel their efforts to shed light on the S-92 MGB and challenge the hype have been recognised.

[geneman]

Squib said :
"Level sensors would be very difficult in a helicopter MGB... It would be better to introduce an emergency lube system."

Point taken, but an MGB oil level sensor and an emergency lube system are not mutually exclusive.

Tedeco and others make electro-optical fluid sensors that would serve the purpose. While not a trivial task to effectively install these or similar sensors in a slightly-modified MGB, it would surely be possible to do this in a much shorter--and less costly--time frame than designing and deploying either an emergency lube system or a run-dry system.

[HeliComparator]

I'm not sure that I understand the need for a level detector. In this case they had a double indication of zero pressure from two separate sensors. There was talk about "splash lubrication" but its not a piston engine! If you have a large volume of oil sitting in the sump not getting pumped round, how is that any better than having no oil at all? - and so how does a level detector help you?

HC

[henra]

I think a second obviously different kind of sensor would have encouraged the pilot(s) a little bit more to think about a ditching.

The Report touches a very important point from my point of view, which is partial or perceived systems knowledge and how it can lead to potentially dangerous alternative solution paths to a given problem taken by the pilots. In this case partial systems knowledge led them to apparently assume that only the pump(s) /sensors failed (where there were indeed 2 of them).
In a hostile environment where alternative A (complete loss of Oil) looks grim (ditching with SS4 floats in >SS4 and cold water), it's easy to be tempted to consider any 'better' alternative B (It's only the pumps or the sensors...) if there is any ambiguity...

The only problem I see with level sensors is that they even fail to work reliably in the comparatively benign environment of automotive engines.
I'm afraid they would cause a disoproportionate amount of false alarms thereby reducing their value to close to zero.

[maxwelg2]

HC, add to that no increase in MRGB temperature when the oil cooler bypass switch was finally activated after 77 seconds from the master caution annunciation, something that IMO should have been a memory requirement.

In the PF's defense there was clearly secondary indication missing information from the RFM on land immediately when the master caution alarm was activated i.e. no MRGB lube oil temperature increase should have been stated as a sign of loss of lube oil in the RFM and not just a reference in the PTM.

At 0948:32, there was continued reading of the procedure, stating that the temperature should increase following activation of the bypass. Shortly thereafter, the PNF mentioned that the oil pressure should stabilize or fluctuate in the range of 5 psi to 25 psi and that the temperature would slowly increase into the red zone. At this point, the PF pointed out that the MGB oil temperature did not increase following the activation of the bypass switch as indicated in the RFM. The PF then reiterated that he believed their indications were related to a sensor malfunction. The pilots did not discuss the fact that the oil temperature was not behaving as expected with the bypass activated.

So did the PF believe that 2 pressure sensors and the temperature sensor all failed at the same time? And if it was a pump failure why did the second pump not deliver pressure albeit churning? So now we have 2 failed pumps, 2 failed pressure sensors, and 1 failed temperature sensor in a A/C with no run-dry time.

A radio discussion began with one of the senior company pilots that had proceeded to the Cougar dispatch centre to see if the crew of CHI91 required any additional assistance. During that communication exchange, the PF indicated that he suspected they had experienced a pump failure. This assessment was based on the fact that while the oil pressure indicator was at zero, the oil temperature indication had not increased and was still indicating normal operating temperatures. It was also indicated that they were headed directly for the closest landfall, in the event that the situation would deteriorate. The pilot in the Cougar dispatch centre acknowledged the information and added that the temperature would increase if the MGB oil bypass switch was selected. The PF acknowledged. The pilot in the Cougar dispatch centre then suggested that they review the emergency descent and ditching checklist to ensure that they would be ready for that eventuality.

Why did the PF not discuss further the key issue regarding the lack of increase in temperature indication with the senior pilot at Cougar dispatch? He had already confirmed that the bypass switch had been activated.

The pilots misdiagnosed the emergency due to a lack of understanding of the MGB oil system and an over-reliance on prevalent expectations that a loss of oil would result in an increase in oil temperature. This led the pilots to incorrectly rely on MGB oil temperature as a secondary indication of an impending MGB failure.

To me the TSB should have went further on this key issue and stated that SAC had not included MRGB temperature indication not increasing with oil cooler bypass switch activated as a key secondary indication of MRGB lube oil loss and failure of the oil cooler bypass switch to prevent further oil loss thus requiring a land immediately condition. Surely the lube oil temperature reading ambient would have been observed during the initial MRGB certification trials during the true run-dry test?

The captain's fixation on reaching shore combined with the first officer's non-assertiveness prevented concerns about CHI91's flight profile from being incorporated into the captain's decision-making process. These breakdowns in crew resource management contributed to the selection of an unsafe flight profile

I don't agree with this statement, the PF had incomplete and falsely depicted information, the RFM was flawed and therefore so were the checklists and emergency procedures.

So I blame SAC, FAA and TC for causing so many fatalities. This is what I suspected all along, the TSB just confirmed it for me.

Safe flying

Max

[chw]

And again as with the S76 Tail Rotor control failure ( saving weight with leave the centering quadrant out) and the 214 ST crash ( the pilot switched of one inverter the standby inverter was not synchronised needed a few extra wires) root cause of the accident is not addressed . Root cause, design engineering failure !

I vote for six steel bolts and move on to the next problem that may occur, what els is lurking to take the (or any) machine down.

[Brian Abraham]

I'm not sure that I understand the need for a level detector. In this case they had a double indication of zero pressure from two separate sensors. There was talk about "splash lubrication" but its not a piston engine! If you have a large volume of oil sitting in the sump not getting pumped round, how is that any better than having no oil at all? - and so how does a level detector help you?I believe geneman makes a quite valid point re having level sensors. Have had two occasions where the MGB dumped all the oil.

In the first (205) the cause was a split "O" ring seal, and of course have no idea how long it took before the simultaneous red light and zero oil pressure. Flew on for approx 15 minutes.

The second occasion (212) the rotor brake drive fractured leaving the disc lying on the cabin roof and dropping the bevel gear and shaft into the guts of the MGB, where it bounced around tearing up gear wheels but continuing to run OK. It took approx 6 minutes for the MGB to empty itself.

I ask, would it not be nice know what was happening to the level? May go a long way towards your decision making, rather than waiting for caution lights and pressure indications. Finding yourself suddenly with zero pressure (say) in the cruise at 9,000 is going to eat up lot of that 11 minutes (as demonstrated) getting to the ground/water.

Buys you time.

Our fixed wing brothers/sister have level indicators on many of their aircraft, so it ain't rocket science.

[Outwest]

So I blame SAC, FAA and TC for causing so many fatalities.

Exactly!!! If they would have acted on the Broome incident, we would not be discussing this today and 17 people would still be alive.

[Outwest]

Our fixed wing brothers/sister have level indicators on many of their aircraft, so it ain't rocket science.

Already on the AW139.....of course only on the ground ;)

[212man]

Probably more useful and practical than an oil level sensor is the solution some other types have, whereby the two pumps take their feed from different levels within the sump. When the higher one loses its supply it generates a caution and when the lower one loses it supply it generates a warning. This gives a sequence that points directly to oil loss.

[Brian Abraham]

By level sensor I should clarify I mean an indicator just like a fuel gauge. If it's leaking you can see the rate at which you are losing fluid.

[HeliComparator]

... the solution some other types have, whereby the two pumps take their feed from different levels within the sump.

I agree of course. The problem with a gauge is that most crews don't fly along looking at the gauge all the time, therefore a departure from normal is only noticed once it brings on a caution light. This is the situation we have in the Super Puma family - a leak reducing the level in the sump will eventually uncover the inlet to the main pump, bring on a light and automaticall bypass the oil cooler. So you get the low level warning and bypass selection intrinsically, from the way the hardware is designed, with no moving parts or clever circuits to go wrong etc. It is a far better design strategy than having a separate electronic level sensor in the difficult environment, separate electrics to move a solenoid valve that only ever gets used in an emergency etc. That is why I am glad I fly EC!

HC

[Brian Abraham]

The problem with a gauge is that most crews don't fly along looking at the gauge all the time, therefore a departure from normal is only noticed once it brings on a caution light.You don't make a regular scan and rely on caution lights? I hope you're joking HC. :ooh:

[chw]

That sound like a brilliant design, North America engineering does not go by that they're design strategy is to meet the rule.
Even so an emergency lube system to extend the 30 minute dry run would be a nice option. Just a AMP meter in the S92 would be nice as well, would it be not nice to know where 200KW is going (nearly 300 HP).

CHW

[maxwelg2]

Probably more useful and practical than an oil level sensor is the solution some other types have, whereby the two pumps take their feed from different levels within the sump. When the higher one loses its supply it generates a caution and when the lower one loses it supply it generates a warning. This gives a sequence that points directly to oil loss.


Good point, so why did SAC not build this into the S92 design, or a ELS such as the S61 which has a published 120 minutes limit at Vy? (RFM: proceed to nearest landing site at an airspeed of approx 70 -90 knots). Would Mr Lappos care to comment?

30-minute run-dry time would perhaps have allowed 491 to land on Hibernia, but the sad fact is that it still wouldn't have made landfall. I still say the PIC should have ditched, but I can understand why not when the type only had SS4 EFS installed and the SS was at SS4 plus the false and ambiguous data provided by the MRGB flight instruments. Without HUEBA and a good chance of a quick capsize the odds of survival probably would not have been much higher, but at least better than a high velocity impact.

I believe that all the Cougar S92s now have SS6 EFS, noticeable by the addition of step feet on the sponsons.

If the TSB recommendations are enforced to the letter we will not see the S92A retained in NL if SAC do not address their inherent design issues and Achilles' heel on this type.

I didn't see any mention of the S92A mounting feet cracks in the report, even though this is not perceived to be a causal factor on the demise of 491 it is still another clear indication that this MRGB design has other serious design flaws.

Until SAC get their act together on the S92 give me a EC225 or 332L2 with their own specific RIPS functionality (332 apparently has heated mats and slip rings same as the EC225 plus a pneumatic boot on the leading edge on the horizontal stabiliser) so we can fly most of the year up here, or the CH-148 MRGB version in the S92A for our hostile waters. We flew the Super Pumas up here for years in the winter and to my knowledge all they did was wear out their gearboxes frequently and were high maintenance. So much for progress...

Safe flying

Max

[rotornut]

No more flights over rough seas...

Oil companies curtail chopper use over rough seas off Newfoundland (http://www.calgaryherald.com/technology/companies+curtail+chopper+over+rough+seas/4264378/story.html)

[HeliComparator]

I hope you're joking HC

Not joking at all. We check the gauges from time to time, but we don't spend a 2 hr transit staring at the gauges. In my experience as a Simulator instructor, if you give crews a failure eg engine or transmission oil temperature rising, pressure falling etc they don't notice it until a caution light comes on. And that is with them in the Simulator expecting the worst! That is the reason why caution lights were invented! Of course it may depend on how rapidly the gauge is moving out of the normal range - if its higher or lower than normal for a long time, it might get noticed.

And as soon as workload is elevated a bit, eg flying an instrument approach, looking at the system gauges just doesn't happen.

We had a real case of an oil cooler fan failure on an AS332L some time ago, so of course transmission oil temperature rises, maybe a degree every 2 or 3 seconds, but crew did not notice until the high temperature warning light came on maybe 2 minutes later.

Its interesting to compare the diametrically opposite philosophies of SAC and EC in terms of HMI:

SAC likes to give crews as much information as possible (thus maximising the potential for misinterpretation by the crews)

EC knows that pilots are stupid and only gives them the information that they really need to know in a black and white way (or grey and red in the case of the EC225) - giving them any more will only confuse them.

On the 225, the gauges have no markings and mostly the gauge range is grey (no more Ts and Ps in the green!). The extremes of the gauge are red lines. If the gauge touches the red line, its out of limits and a caution light comes on and the numeric value of the parameter appears in yellow or red. But there is no sense of how far into the red it goes since the red line is the end of gauge travel, its either red or its not - you either have to apply the RFM procedure or you don't. You can set it to show the numeric values all the time, but that is only for those of a nervous disposition.

On the EC175 I believe the standard display will not include system gauges - they will only pop up if something goes into an amber or red range.

Being a stupid pilot, I prefer the EC way.

HC

[zalt]

The TSB report is a tour de force.

Its important not to over concentrate on the indications of oil loss when the root cause is the repeat failure of simple component and a sub-standard gearbox.

However, anyone who does want to analyse the indication aspects need to consider the following:

1) The Amber Caution was followed by a Red Warning so fast that the crew didn't have chance to notice the first (this would not have been a surprise to Sikorsky who afterall wanted the bypas valve activated in just 5s to stop a rapid and catestrophic oil leak)

2) The FSI checklist in use was however written with the assumption that their would be a much more gradual leak (as used in all training scenarios).

3) As a result the NHP had to thumb page thru page to find the Oil P Warning as it wasn't in the index.

4) The fact that there had been 4 oil system S-92 emergencies in the past of which 3 were pump failures and 1 that "was not considered a cause for concern since the problem was attributed to another company's field repair".

5) Sikorsky had concealed that during the 6 August 2002 initial certification loss of lubricant test (when they drained the MGB and to just the 1,3 gallon residual oil) the MGB "suffered a catastrophic failure about 11 minutes after the test was started...due to excessive temperature caused by lack of lubrication".

6) As Brains said: Finding yourself suddenly with zero pressure (say) in the cruise at 9,000 is going to eat up lot of that 11 minutes (as demonstrated) getting to the ground/water.

7) As the AAIB described the S-92 this week, it does have "sub-optimal switch locations and markings" in the cockpit Air Accidents Investigation: Sikorsky S-92A, G-SARC (http://www.aaib.gov.uk/publications/bulletins/february_2011/sikorsky_s_92a__g_sarc.cfm)

8) The sea state was at the limits of the basic S-92 floats (as Cougar had not bought the enhanced floats - though they were not available when the S-92 first entered service)

Sikorsky had 6.5 years to address the MGBs shortcomings, the Cougar crew had just seconds.

[Outwest]

or a ELS such as the S61 which has a published 120 minutes limit at Vy? (RFM: proceed to nearest landing site at an airspeed of approx 70 -90 knots).

Unfortunately this is a misconception about the ELS on the S61.

The 120 minutes mentioned in the RFM deals with the maximum time allowed for the electric ELS pump, not how long the MGB can be flown on ELS. The ELS system only supplies oil to the babbitt bearings, which would not survive more than a few seconds without oil, which would then either cause the engine inputs to seize or cause a fire in the magnesium gearbox.....catastrophic.

I hope S61 crews are not lulled into thinking they can fly for 120 mins on ELS.:=

[zalt]

Not another Sikorsky RFM misconception?

[Brian Abraham]

HC, I was being somewhat deliberately provocative in my post. I've seen pilots flying in excess of half an hour in the cruise VFR (non existent work load) with an engine oil pressure gauge reading zero and not noticing until it was pointed out to them (engineered to see how long before a response). Perhaps the manufacturers could save a bit of money by just providing idiot lights as in our motor vehicles. A sign we have become a little too comfortable with the reliability of our machinery?

[Outwest]

Not another Sikorsky RFM misconception?

Actually probably more of a misconception by pilots and training staff over the years, although admittedly a bit vague in the RFM.

S61 crews need to be aware that on ELS none of the gears (planetary, sun, TTO, etc) are receiving lube oil, so they should consider that the 61 transmission will probably not last much longer than the 92 did.

[zalt]

Perhaps ambiguity is SAC's middle name.:uhoh:

[SASless]

Being a stupid pilot, I prefer the EC way.



Over the years we have had ample evidence of that bias....now we finally know why!:E

[Outwest]

Perhaps ambiguity is SAC's middle name.

Not defending SAC in any way, but I think most manufactures are deliberately vague in places. Even in the AW139, which has a true and demonstrated 30 min run dry MGB, they don't mention that number in QRH.

[maxwelg2]

Outwest, thanks for clarifying, I did go back and look at older posts on the main S92 thread, there was a lot of discussion on ELS just after 491. Here's the link for those interested in refreshing their memory.

http://www.pprune.org/rotorheads/163206-sikorsky-s-92-design-operations-63.html#post4794848

The statement about the S61 ELS is on page 70 and was your own but I missed the other information wrt. the babbitt bearings and their magnesium gearbox fuel source. At least the S61 ELS comes on automatically and it has one.

I recall reading that the CH-148 ELS was meant to be similar to the EC225 i.e. glycol cooled and 30-minute true run-dry conditions i.e. complete loss of lube oil. For me that is what SAC should have put into the S92 from day 1.

The sad fact is that we're nearly 2 years on after 491 and SAC still haven't provided a solution to the MRGB issues and tried to play the "oh it still meets FAA requirements" card with its steel studs now. Well guess what, it doesn't, never did after Broome, should have been grounded until SAC fixed the problem. What about the premature oil filter false blockages requiring much more extensive filter inspections, which caused additional wear on the titanium studs? The root cause of the mounting feet cracks still hasn't been published, do SAC actually know yet?

I now wonder how long TC will give SAC to address these long-outstanding issues.

At least now thanks to this forum and the TSB report everybody is aware of the real issues.

Perhaps the oil companies should invest in the EC225 and return the S92s as "unfit for required use".

Safe flying

Max

[Outwest]

Your welcome Max, and I fully support your statement:

Well guess what, it doesn't, never did after Broome, should have been grounded until SAC fixed the problem.

I just went back to the posts you mentioned and I think I may have added to the confusion over the S61......again due to some vagueness of the RFM.

I will re-state the S61 MGB has NO demonstrated run dry capability that I'm aware of. The ELS will only give you time (how much no one knows) to make a controlled landing/ditching.

Anyone who has access to the S61 RFM can reference Part 2 Sec 1, page 1-5 for clarification on just what the ELS supplies oil to.

[zalt]

The sad fact is that we're nearly 2 years on after 491 and SAC still haven't provided a solution to the MRGB issues and tried to play the "oh it still meets FAA requirements" card with its steel studs now.

Very true. Their heads are in the sand and their ar8es are on show.

[Flapwing]

CBC News - Nfld. & Labrador - N.L. chopper crash recordings detail tense moments (http://www.cbc.ca/canada/newfoundland-labrador/story/2011/02/11/nl-cougar-tape-211.html)

[The Sultan]

From the report.

1. The pilot's delay in flipping the bypass switch would have had no effect.
2. The main transmission was not compromised to such an extent to degrade the basic aircraft autorotation capability.
3. The FM states the only response to a loss of tail rotor thrust is immediate autorotation.
4. The transmission failure was a loss of drive to the tail rotor.
5. Loss of tail rotor resulted in extreme attitude excursions which had to have an impact on the ability of the crew to pull off a successful autorotation.

As the S-92 requires a lot of torque to the tail rotor, even in cruise, is this aircraft even capable of surviving a total loss of tail rotor thrust? Did SAC actually test their flight manual procedures to show the aircraft can be successfully autorotated with no tail rotor thrust?

It has been reported that there was an S-92 that lost tail rotor control resulting in a runway landing in Norway. The loss of control does not equate to total loss of thrust as the elastomers can maintain the tail rotor at a thrust level.

All helicopters I have flown in (and there are many) can have a total tail rotor failure in cruise flight and can be guided to a controlled run on landing or an auto into a selected area. I admit none of these have highly canted tail rotors.

The Sultan

[rumline]

In a dark corner somewhere... Sikorsky tested thier MGB without oil.

It ran for 11 minutes before coming apart.

At 12:15 UTC. at 9000ft Cougar 91's MGB pukes out all its oil....

and exactly 11 minutes later...

:mad:

They didn't stand a chance.

Godspeed.

[Outwest]

As the S-92 requires a lot of torque to the tail rotor, even in cruise, is this aircraft even capable of surviving a total loss of tail rotor thrust? Did SAC actually test their flight manual procedures to show the aircraft can be successfully autorotated with no tail rotor thrust?

Loss of thrust as in a fixed pitch situation, as opposed to loss of drive or complete loss of the unit are 2 completely different situations. Nick took the time to explain to me a number of years ago the relationship of the disk of the turning tail rotor and its effective vertical fin area. So, loss of DRIVE to the tail rotor means you have lost that fin area that would assist in keeping the a/c from swapping ends......

[Outwest]

What type of system does the AW139 use to achieve it?

Good question, but I think the technical term is skookumness ;)

[dangermouse]

although not used for offshore in the civil world

EH101 has full 30 minute capability, 5000+ SHP

so it is possible

DM

[Paul Cantrell]

I'd like to thank Mel Effluent for posting that link - a very interesting and sad report. I was up all night reading it.

I'm curious for those who do a lot of twin engine flying how much emphasis an operator like Cougar puts on autorotative descents during initial and recurrent training? My initial assumption when I first heard about the accident was that the MRG had seized, but reading the report it sounds like it was flying right until impact.

Besides the yaw from the TR failure, what kind of control issues would a pilot be encountering on a S92 that would compromise the execution of the autorotation? Would the aircraft still be experiencing yaw kicks after the collective was all the way down? Does that still couple into pitch with the Sikorsky (canted) TR design once you are in autorotation? (I wouldn't think so).

Finally, that far offshore, how hard is it to judge height above the water for a proper flare initiation? (I'm sure you could use a RADALT but in good VFR I would think most of us would judge the flare visually).

I was also under the assumption that a gearbox would give you lots of warning before it finally let go - noise, vibration, etc. This report seems to indicate that isn't always the case.

Paul

[lelebebbel]

I was also under the assumption that a gearbox would give you lots of warning before it finally let go - noise, vibration, etc. This report seems to indicate that isn't always the case.
40 years ago, my dad was nearly killed when the gearbox of his Yamaha seized without warning. A part had cracked and jammed itself in between some of the rotating bits, immediately stopping the rear wheel.
This may only be remotely comparable to a helicopter gearbox failure - then again, i don't believe there are many people who have experienced one of those and lived to tell about it.

[squib66]

Yes EH101 plus the US military have reuired a 30 minute capability for years (early 70s?) so there are more military helicopters that are capable.

In fact AS332L managed 28 minutes before failure back in the early 90s and EC225 50 minutes (with the emergency cooling system that EC installed to protect crew and passenegrs).

The S-92 gearbox has performance stuck in the 1970s along with the 76, 365/155 and other helicopters of that era.

[Brian Abraham]

To repeat my usual rant.....just what is a human life worth?SAS, as much as an oil company is unwilling to pay.

[212man]

Industry Insider,
The EC-155 had 25 minutes. It's stated in the RFM, I stated it in this thread and, strangely enough, the TSB state it in their report!

[maxwelg2]

From section 1.18.5.5 of the TSB report


TC produced a concern paper which stated that 5 seconds was insufficient for the pilot to engage the MGB oil bypass switch. Requiring the pilot to action a system of this type in such a short time was considered unusual, and TC stated its belief that this function should be automated. Sikorsky's response was to explain that 5 seconds represented the worst-case scenario. TC did not agree with Sikorsky's position. In an effort to mitigate risk, TC requested that Sikorsky provide additional guidance that would help the pilot determine whether the switch was selected quickly enough to trap sufficient oil, and to monitor the health of the transmission in bypass mode. In response, Sikorsky revised the Rotorcraft Flight Manual (RFM) to identify the range of MGB oil temperature and pressure indications pilots should expect to see after the bypass switch had been activated. Sikorsky also identified symptoms which would warrant a "land immediately" situation. TC accepted the RFM revision and on 07 February 2005, the S-92A helicopter was granted a TC type certificate based on a validation of the FAA approval.

So even though TC identified the issue IMO they accepted a rather poor solution. They should have insisted on an automatic cooler bypass and looked more at the temperature readings in the event of total MRGB loss as witnessed during the total oil loss test on 06 August 2002. Were the FAA in attendance at that test? What exactly did TC witness in the level 2, nothing, just a paper review at SAC? Why did TC not review the concerns that the JAA had raised?

The JAA are stated in the report to have referred to the Blackhawk's track record but just how similar are the S92 and Blackhawk MRGBs to draw conclusions from this comparison? Did the Blackhawk MRGB have steel or titanium oil filter housing studs and/or the high filter changeout issues? How does the Blackhawk MRGB achieve 30-minute run-dry capability?

IMO each aircraft type should be reviewed and approved on its own merits with no "follow-through" credit assumed from previous/similar designs. This for me was a fundamental error by the FAA and TC.

History has shown how this type of design approval can have serious consequences e.g. Bristow 56C G-TIGK lightening strike back in Jan '95 when flying out to Brae "A" highlighting issue via change of tail rotor to composite carbon fibre and aluminium reinforcement edging. I worked with one of the PAX after that successful A/R and he told me first-hand how lucky they were and the skill the pilots showed to save their lives.

Looks like 15+ years later we're still making the same mistakes in this industry. This needs to change.

Safe flying

Max

[squib66]

Max

The FAA certified the Sikorsky design. The FAA usually witness major tests.

JAA and TC were separately validating the FAA certification. They could both only talk to the FAA (and Sikorsky through the FAA).

I can only guess that the H-60 Blackhawk experience was offered up via FAA to justify their certification. Actually I do believe good-prior experience can be used to justify a design. However it has to be relavent (the fatal BV234 accident off the Shetlands in 1984 is a case of an aircraft changing operating environment and suffering) and bad-prior experience on other types needs to be considered too!

What is odd is that Sikorsky's experience with Titanium studs is not from the H-60, but the H-53 according to the TSB (note the E model, which suggests the material may have been dropped on subsequent H-53s) and in an installation with a robust cluster of 6 studs, not just the 3 Sikorsky introduced for the S-92:

Sikorsky selected the titanium alloy stud because these had been used successfully on other Sikorsky products, such as the CH-53E Sea Stallion which utilizes six titanium studs to attach the oil filter bowl to the MGB.

The first opportunity to question the Blackhawk heritage was not Broome, but the Norsk incident in May 2005. I say that because the vespel splines that failed were said to be an H-60 feature that had never been a problem on the H-60. Certainly it was questioned here: http://www.pprune.org/rotorheads/163206-sikorsky-s-92-design-operations.html

[squib66]

212man

Thanks for explain the EC155 capability again. Having seen the comments on past kidnaps in Nigeria I'm sure having 25 minutes tested would be more reassuring that just 11 when flying over the delta.

It does go to show that some OEMs have been able to take an earlier design build it into an bigger airframe and still expand the loss of lube resilience.

All
It is well worth reading the http://www.pprune.org/rotorheads/163...perations.html (http://www.pprune.org/rotorheads/163206-sikorsky-s-92-design-operations.html) thread (as mentioned by TSB in their report) for the period between the catestrophic MGB test in early August 2002 (done the conventional way with just residual oil) and the December 2002 FAA certification (with the bypass added). There is a hint of the schedule pressure there.

[maxwelg2]

Squib66

You got me going back over old posts from the main S92 thread. Here's some extracts that caught my eye:

The S-92 has 4 main rotor blades (last time I counted) and will have them for the next decade, anyway. The vibration is very nice, thank you, with levels that are better than the President's S-61, thanks to the 4 (that's four) main rotor blades, and also the very good computer driven vibration absorber system that we use.

IMO the S92 vibrates worse than any helo I've flew in over 20 years. Linked to MRGB mounting feet cracks, accelerated fatigue of titanium studs?

Breaking new ground for medium-weight helicopters, the S-92 provides unprecedented levels of safety and reliability. It is the only aircraft in its class certified to the latest specifications for flaw tolerance, bird strike capability and turbine burst protection. In addition to its civil helicopter capabilities, the rotor system and dynamic components are designed to meet the UH-60 BLACK HAWK ballistic tolerance requirements and all gearboxes are capable of running 30 minutes after loss of oil. Corrosion protection meets or exceeds current maritime standards

Note the highlighted wording, doesn't say run-dry but does refer to the UH-60 which apparently does have 30-minute run dry time capability. This statement was the one issued by SAC post-FAA certification approval.

It was the fastest, cleanest certification anyone at Sikorsky can remember. The first certification data flight was made last December, the FAA got on board in September, and we were done with all flights exactly one year later, Dec 12. The data was all processed in real time, so the FAA was ready to sign on Dec 17 (Wright Brothers day!) so they did. Not a bad data point in the thousands taken.

Perhaps in hindsight too fast considering some of the base errors we now unfortunately know about.

The "regular" Sikorsky military design rules were also met, including ballistics and object strikes, since we intend to use the whole drive train (engines, transmissions, rotors and blades) on the most advanced version of the Black Hawk in a few years. The gearboxes bolt right into the Hawk family.

Is not one of the "regular" mil-spec rules 30-minute run-dry time? The Canadian military certainly won't accept the CH-148 without this.


FYI, you also get a main transmission that ran 3 hours after a massive oil leak, damage tolerant rotor and structural components, full bird strike protection (controls and drive shaft covers that are nearly ballistic so birds don't cave them in at Vne), and tolerance of engine burst events. {You also get ballistic tolerance, based on the H-60 design requirements, but one hopes this is not necessary in the oil patch!}

I'm assuming reference to the simulated oil cooler leak and bypass switch mode. No mention of what happens when the MRGB is run dry though...

With the S-92, we applied for a certification basis in the FUTURE to capture the draft regulations. This meant that we reached ahead to capture those safety aspects.

Similarly, the S-92 is the only large helicopter to apply for JAR certification, and will shortly work with the JAR test community to get that done.

JAA didn't like the work-around the 30-minute run-dry time requirement, so why was this not looked into more detail e.g. closer analysis of MRGB temperature? IMO nobody appears to have looked at the 11 minute data, instead looked at the 3-hour data. Was it made available to JAA via the FAA?

Your comments are quite valid if one carries the old philosophy of needing to have the pilot stay as a gauge-tender, with one eye on the limit and the other on the rest of the world, but we designed the system to free you of that workload

Well then why did the MRGB temperature gauge get missed off that list?

The oil system of the S-92 is virtually identical to the Black Hawk, and probably the 225. It is dual in every way, as are the indications. The pilots in this emergency landed with an aircraft that could have been flown for hunderds of hours, yet you have purposely posted inuendo that ditching was imminent, that fleets are grounded, and that the sky is falling, and now you need to see the oil system so you can pronounce the S-92 still born.

Comment posted after the Norsk Hydro vespel spline failure. So where is the secondary MRGB temperature sensor? Why not have 2 temperature sensors, one on the feed to the MRGB and one on the return line, that way you have dual-redundancy and also can monitor delta-T for an additional condition-based monitoring tool?

All the above quotes were from the same person, namely the S92 program director. As I read it there is a very strong bias here towards not only the S92 but a big push to get this A/C into production and fleets. I wonder why...and what will change now?

Simple, IMO the S92 design errors will have to be fixed or the A/C will be grounded for civilian use and a suitable replacement such as the EC225 procured by the oil companies. That means acceptable vibration levels, noise levels, robust and proven MRGB.

Safe flying

Max

[mickjoebill]

but why not simply require Supplemental Air Devices for all over water flights and prevent folks having to solely rely upon a single breath to escape from a submerged aircraft?

A few years ago I completed an offshore course in Rotterdam NUTEC which included a HUET course, designed for oil rig workers. We were taught the use of "Shark" brand vests that had a rebreather and a vest that had a rebreather (Shark airpocket plus) with the addition of a small bottle of 02 that inflated the rebreather bladder (not enough for it to become buoyant) so it gave another +20 seconds of air.

We were unable to have a practice with any ancillary air because according to the instructor the admin and H&S paperwork makes it onerous and also due to the number of people they teach that their would likely be a medical issue sooner or later. Shark website states that "Air Pocket Plus has been designed to minimize the risk of cerebral arterial gas embolism which results from any system which introduces supplementary gas" So perhaps this is what the training organisations worried about?


Looking far forward, what is needed is a more user friendly face mask for passengers something that can be easily donned or better yet, is comfortable enough to worn for the entire flight. All of the spare air and rebreathers don't use a mask but a mouthpiece, it is quite difficult to think about not breathing through your nose, especially if suffering cold shock. A nose clip avoids involuntary water inhalation, this they are uncomfortable to wear for the entire flight and unlikely to be deployed by a novice in an emergency in my view.

Anyway, helmets should be a priority followed by spare air?

Thinking high tech, for passengers, how about a one piece sealed helmet that, on contact with water switches from environmental air to (1 minute) of bottled air housed in the helmet? Would need some new technology to create a seal at the neck or otherwise the helmet could be incorporated into the design of the immersion suit.

Although an immersion suite protects most parts of the body it offers zero protection for the airway.


Mickjoebill

[SASless]

Where did SAC claim a 30 minute run dry capability for the 92? Have I missed it somehow?

dynamic components are designed to meet the UH-60 BLACK HAWK ballistic tolerance requirements and all gearboxes are capable of running 30 minutes after loss of oil.[/QUOTE]

[QUOTE]you also get a main transmission that ran 3 hours after a massive oil leak,

It did. Did SAC hide the results of another test that failed? Did the FAA ignore that failure if it in fact occurred? Who stamped "OK" on the Test? SAC or the FAA?

Nothing about "Run Dry" said.

How many certification authorities in fact certified the S-92? How many refused to certifiy the S-92?

Why is it the focus is only on SAC?

That is not where the finger should be pointing unless SAC and the FAA for sure are married at the hip! Are they?

[riff_raff]

Sultan,

You bring up a good point with regards to taking a closer look at the effects the tail rotor drive failure had. The TSB report notes that the data recorder showed an indication of rotor brake engagement just a few seconds before the data acquisition ended. And I believe the rotor brake is located where the tail rotor drive exits the MRGB housing. The investigators seemed to think that excessive motion of the tail rotor gear shaft as it failed may have affected the rotor brake.

The investigation clearly showed that the tail rotor drive gear failed structurally. Under a loss of lube event, this should not be unexpected for a couple reasons.

First, the tail rotor drive gear was likely a spiral bevel gear. Spiral bevel gear meshes generate lots of heat and thus are prone to scoring. A loss of oil cooling to this spiral bevel mesh would quickly result in contact scoring, overheating, loss of mechanical strength in the gear teeth, and finally structural failure of the gear teeth.

Second, the tail rotor driven gear was supported by a tapered roller bearing set. Once again, tapered roller bearings tend to generate lots of friction heat where the roller big ends rub against the race shoulder. A loss of oil cooling to this area would quickly result in overheating of the rollers and race, loss of mechanical strength, and finally structural failure. These problems would be made worse if the tail rotor drive was subjected to high torque loads in addition to the loss of oil flow.

Just one more interesting aspect in the chain of events that caused this tragedy.

[Treg]

Hi Mickjoebill

Speaking as the chairman of the Asia Pacific Training Providers Advisory Group, a body made up of leading HUET providers in the region that train to the international OPITO standard; can I reinforce that training providers, like aviation companies, are subject to many regulations and their associated audit process – simply put, we train to the standard or loose accreditation.

However, twice yearly TPAG’s meet to discuss ways of improving offshore safety training, and as of last year this now includes a global safety conference involving our regional counterparts from the other OPITO regions: Middle East Africa, Europe and The Americas.

At the global conference held in Abu Dhabi last November, where sixty training provider representatives were in attendance, the MEA and AP TPAG’s submitted a proposal to increase HUET training standards to include cross-cabin escapes as an option when individuals requested “more realistic” training (current drills and trainee contact-time do not permit additional [non-OPITO] exercises being undertaken in a standard training day). This proposal was rejected with the rationale that change must be generated by oil companies.

Although frustrating for training providers, we; like aviators, are obliged to operate within the confines of documented standards. Notwithstanding this point, many providers can tailor HUET to individual client requirements if the client chooses not to undertake an internationally recognised course.

An example of this was HUET training provided to the Red Bull Air Race pilots prior to the last Perth race where an aircraft ended up in the Swan River inverted and the pilot made a successful escape using an emergency air supply. In this instance a Shark product would have been impractical due to the high ‘G’ associated with racing, so an appropriate solution was identified and a training course developed.

Of course another option to generate change would be for aviation companies to lobby oil companies, but how do you think that would work out?

PS: should any aviation representative wish get a better understanding of how international HUET standards evolve, please don’t hesitate to contact me.

[maxwelg2]

Mickjoebill

As I'm originally from the UK I did offshore refreshers just when the Shark rebreather came out, we had to do the "dry" test first then used the "boil-in-the-bag" rebreather in a similar fashion to the HUEBA training we get over here in Canada i.e. face down in the water, then at a lower level < 1 metre albeit in the HUEBA training you're in a flight seat and turned upside down (you have to be able to deploy the HUEBA in a capsize situation).

I remember the extra effort required even after 8 years since my last UK refresher at NUTEC Aberdeen just in the pool to use the Shark rebreather even just under 1 metre of water pressure. Since 1 meter = 1/10th of an atmosphere I wouldn't want to try a fight against 10 metres = 30 feet which is what they reckon the depth was at when 2 survivors escaped but only one miraculously survived without HUEBA/rebreather pocket.

I recall the rebreather using your own breath only. I just wonder how effective they would be with cold water shock, also at such depths. Perhaps the small air cylinder is a relatively new thing or my memory is getting dusty.

I have done two HUEBA training courses now, one just after they were finally brought in after 491 (they were in the works for over 6 years) and again just last year during my BST-R (Canadian survival course refresher). The secret is to use the face mask which we strap to our arm, the nose clips IMO are a waste of time. Another reason for the face mask is to see where you're going better and if there are any fuel leaks, which happened in 491, to prevent damage to your eyes.

The military have been using HUEBAs for many years and they have saved many lives. Their requirement was based on hostile territory flying over sea and a higher risk of ditching. The civilian industry requirement is more to do with the extended flight times in relatively hostile territory (sea state, icing conditions, lightening strike potential etc.) and more lately due to the S92A lack of MRGB run-dry capability, which IMO deems it unsuitable for Cat A classification.

The key is reducing the risk of ditching to as long as reasonably practicable (ALARP), but in the event that this happens I'm glad we have the HUEBAs now. Hopefully after the TSB report recommendations these will be adopted by all helo ops, not just those in the Grand Banks.

There is a fine line between realistic training and increased risk to trainees. If a more stringent medical was put in place perhaps we could introduce cold-water shock awareness, deployment of HUEBA in the HUET, and a general increase in fitness level required for offshore certification. Sadly though our aging oil and gas workers (including myself) would experience a high failure rate, costing the oil companies a huge amount of money to train up new blood. IMO this is probably the main reason why this will never go ahead.

It is up to the individual to decide if he/she is willing to take the inherent risks associated with our industry based on their own self-management of health and fitness. Things are improving albeit slowly and it unfortunately takes tragedies such as 491 to make them happen. That's just the way big oil works.

There is a much more detailed thread on this tragedy, perhaps the moderators will merge the two of these.

Safe flying

Max

[maxwelg2]

Recently in the news, looks like not all Cougar S92s are currently upgraded to SS6 EFS.

No flights over rough seas - Business - The Telegram (http://www.thetelegram.com/Business/2011-02-11/article-2218089/No-flights-over-rough-seas/1)

Safe flying

Max

[Brian Abraham]

Don't know when Sikorsky put it out SAS

http://i101.photobucket.com/albums/m56/babraham227/92.jpg

And the difference

http://www.cbc.ca/fifth/2009-2010/cougar_491/images/s92_technical_brochure.jpg

[SASless]

Brian,

My guess is 2003 judging by the date on the brochure (very hard to read for these old eyes so might actually be different).

What I did notice is at the Top of the thing they do say "Run Dry" but at the bottom of the thing they say "30 minute Run after Oil Loss and 140% Torque application".

The important question is did they make the "Run Dry" claim in their Technical Data/Certification Data/RFM/Checklist/Training Material?

[Winnie]

According to the report there is NO indication that the crew thought they had 30 min dry run.

The other thing I noticed, and I actually teach this to PPL/CPL is "Bucket speed" and the Co-pilot mentioned this (using L/D Max instead), but the Captain was not familiar.

Perhaps this also shows some lack of systems knowledge on a broader spectrum (not just for this crew, but for most of us), showing the need to reduce power and slow down, in case of an emergency? Counter intuitive as well.

Anyways, I am by no stretch of the imagination any sort of expert on this, so I will shut up now.

Cheers
H.

[squib66]

Brian

I think 2003 also like SASless. But TSB do mention such terms were being used well after delivery to Cougar too.

SASless

Your point about the FAA is noted but it is the job of the applicant (Sikorsky) to show compliance (i.e state they have complied with the rule and how) and then for the FAA to verify that.

Where the FAA may well be at serious fault is in the re-interpretation of the rule after the failure in August 2002.

As that resulted in a means of compliance that differed from all former (and since!) loss of lube tests I believe that should have been recorded as an Equivalent Safety Finding on the TC Data Sheet and at least it would have been visible and rightly open to challenge.

The fact they did the first test the usual way does rather indicate that Sikorsky (and FAA) understood what should have been done but fudged it with the bypass system in a panic when the failure occured. The apparently lengthy debate the JAA had seems to have been, at least, in part due to that re-interpretation.

Winnie

The crew had a right to expect (even if they didn't understand FAR29) a gearbox that could run for 30 minutes after any credible type of oil loss because that is the requirement in the latest FARs which Sikorsky were happy to trumpet they complied with.

Sikorsky and FAA should have had a wake up call after Broome which showed that there were failures that were not extremely remote that the bypass system could not cope with.

I wonder if they need a better system knowledge.

[pasptoo]

The crew had a right to expect (even if they didn't understand FAR29) a gearbox that could run for 30 minutes after any credible type of oil loss because that is the requirement in the latest FARs which Sikorsky were happy to trumpet they complied with.

But that is not what the RFM or ECL says.

Bucket Speed, Min Power call it what you like, with GB problems wouldn't (shouldn't) you fly using the lowest amount of power possible?

P :sad:

(Treetoupow)

[SansAnhedral]

I can almost guarantee Ti studs were originally used for weight issues. During a period of time during work on the CH148 production modification SAC was willing to pay the engineering teams multiple thousands of dollars worth of engineering hours per pound saved...especially from the dynamic system. The 92 was seemingly perpetually overweight.

And its laughable to consider the gearboxes/oil filter arrangement of the 92 versus UH60 as being one-in-the-same. For one thing, the filter on the 60 is mounted vertically, not cantilevered off the side of the MGB casting shaking on giant moment arm with the 1P.

The relationship between 92 and S70/UH60 was only ever as close as whoever the potential customer wanted it to be.

US or foreign military? Its the same proven helicopter!

Commercial or VVIP? Its an thorough evolution into a new state of the art machine, not some old 1970s technology! (Its got AVC!)

[FlyingHead]

To Nick and all the expert out there, can the Aux Tank can be the cause of the titanium failure. Let me explain, the only 2 aircrafts which had studs failure where equipped with the same aux tank. Is it possible the aux tank which is located under the transmission, induce a vibrations that can be the source of the studs break down?

FH

[500e]

brian
I think I posted that sheet "tech info 7" some pages ago but had the same response, not in the RFM, but people had that thought in their minds, & when it is put it in the sea, or fly it I don't know what I would do, I know what pilots were told to do but!! (FAR29 said?) & it is a big but, how many will die of hypothermia? (remember the suits also came in for criticism)
Read report there appear to be faults all round, FAA, should have been more proactive, Sikorsky should have fronted up & said in plain speak it wont run for 30 min as stated in TI 7, & pilot CRM lacking.
A really sad outcome for all, especially the families

[HeliComparator]

Just noticed that Rick Burt left Cougar in mid 2010, now with CHC - was his departure related to the accident?

[Lonewolf_50]

To Nick and all the expert out there, can the Aux Tank can be the cause of the titanium failure. Let me explain, the only 2 aircrafts which had studs failure where equipped with the same aux tank. Is it possible the aux tank which is located under the transmission, induce a vibrations that can be the source of the studs break down?

Do you think it would be a freq related to the one per rev or the four per rev vibration? :confused:


Transport Canada require that supplemental underwater breathing apparatus be mandatory for all occupants of helicopters involved in overwater flights who are required to wear a Passenger Transportation Suit System.




HEEDS bottles for everyone.

Leads to question: do all Pax on such flights have to show a "I am HEEDS bottle trained" card or be denied passage?

Did HEEDS training in USN a while back ... over a decade ago ... I don't think it's a trivial training cost, depending on if you have to do a full pool exposure or not to meet a training spec.

EDIT to ADD:







In the discussion of MGB malfunctions for the SH-60 family, a SAC product which I flew, there is this WARNING (NATOPS Manual a couple of revs out of date, but probably still there, as it is the same as when I first learned it in the late 80's)WARNING


• Catastrophic transmission failure will result in loss of helicopter control. Consideration should be given to transiting at minimum power airspeed and a low altitude flight profile (approximately 80 feet and 80 KIAS) to permit a quick flare followed by an immediate landing/ditching.• Operation of the main gearbox with no oil pressure may result in failure of the tail rotor drive takeoff pinion gear and subsequent loss of tail rotor drive.Note• A loss of all main transmission lubricating oil may result in unreliable temperature indications from the main transmission temperature gauge and temperature sensor (caution light).Question: do most helicopters have similar language to the above? (EDIT: reloading the page just gave me the second half of the report, so I see analysis of "similar language" on that score.)



I would expect SAC helicopters to have similar language, unless that is some Navese imported from another helicopter type into the SH-60 manual.
EDIT: I just noticed that the training manual does not appear to have made a point in re the NATOPS Note above: The PTM does not include information regarding how the temperature gauge senses temperature (i.e., that it is a wet bulb requiring immersion in oil) or that it would be unreliable in the event of a total loss of oil, as it would, in such a case, measure ambient temperature inside the MGB case. :(

And ...
The RFM makes no mention of how MGB oil temperature will react to a complete loss of lubricating oil (i.e., that it will be unreliable because it measures ambient temperature inside the MGB case). :(

I noted in the narrative of the mishap :{:{ that for one reason or another, the investigators infer that the crew either did not expect imminent failure ... or as SASless so poignantly put it, they were faced with not just "between Devil and Deep Blue Sea" but also "sea state that may kill us before we get out, and freeze us if we do" as choices available.

Vaya con Dios, amigos. :{:{
LAST EDIT: From the report
1.18.6 Social Media

Starting in March 2000, before the S-92A went into commercial use, website visitors engaged in discussions about the introduction of the S-92A. Many of the individuals who posted on this website chose to remain anonymous. However, others such as one of Sikorsky's senior managers for the S-92A program, who was a regular contributor to the online discussion, chose to identify themselves. Over the course of several years, the subject of the S-92A's compliance with Part 29 was discussed at length among members of this internet forum. From these online discussions, it was evident that those involved understood that the S-92A did not have a run dry capability.
It was determined during the TSB investigation that at least one senior manager, and several other pilots at Cougar Helicopters periodically reviewed the material posted on the above mentioned internet forum.
PPRUNE??? :confused:

[[email protected]]

From these online discussions, it was evident that those involved understood that the S-92A did not have a run dry capability. Not before the Cougar crash it wasn't.

SAC has been consistently economical with its marketing hyperbole - the 'heritage' claimed from the 60 implied similar components with proven track records but it now seems that any compatibility is only backwards such that the S-92 transmission could be retro-fitted to the 60 if it needed to be upgraded.

SAC traded heavily on the safety credentials of its new baby - ironically those credentials appear to have been acquired by obfuscation and manipulation of weak legislation.

[212man]

Not before the Cougar crash it wasn't.

That's the point - they were! Why do you think HC and others were so persistent in their requests from Nick? Just some whim?

[Variable Load]

Not before the Cougar crash it wasn't.

It was well know LONG before the Cougar crash. Just go back and look at the S92 design thread and the EC225 vs S92 bashing thread between Lappos and HeliComparator to see it all in it's glory. This was in 2004/5!

Crab's reputation takes another dive :E

[topendtorque]

Finally came back to look at this thread as it intrigued the heck out of me. I also made an OB way back about whether the oil temp gauge worked off a wet bulb or not. If it did, then the temp guage will quite quickly reduce in temp as the oil disappears, (the same as a motor car water radiator wet bulb after one clobbers a Kangaroo or some other road loiterer and buggers the radiator) leading to a false conclusion that all may not be quite so bad. This looks like a conclusion reached by the crew in the lead up paras of the report when they levelled off at 800 feet.

Nowadays we all seem to have to adhere to these blessed SMS courses and manuals.

This report overlooks any safety aspect in the company SMS material (according to the report) that may emanate from lack of oil or how the wet bulb will not then work, and what to do about it.

Fat lot of good all that money spent on SMS in this case. Loaded the crew up with a whole heap of gaff, except the really important stuff!

I wonder if the recurrency training is now doing anything about this, not only this type but all types that use a wet bulb sensor.

In the extract below one can see clearly why the pilot made the mistake of flying on. I.E. no knowledge, or simply overlooked, how to interpret a cooling wet bulb temp after it had first run hot. together of course with no oil pressure.

It is so sad that something so simple can be overlooked and lead to catastrophe. A revolting systemic abomination.

1.17.3.2 S-92A Classroom Training

For the S-92A, Cougar Helicopters sends many of its pilots to the Flight Safety International (FSI) facility in West Palm Beach, Florida, for the initial course and subsequent recurrent training. Although less frequently, Cougar Helicopters also sends pilots to the FSI facility at Farnborough, United Kingdom. The captain had completed his most recent recurrent training from 05 to 09 January 2009 at the FSI facility at Farnborough UK. Having completed his initial S-92A training in May 2008, the first officer was due for recurrent training in June 2009.
FSI has been the Sikorsky factory-authorized training source for pilots and maintenance technicians since 1983. The FSI web site advises that it is dedicated to keeping its instruction accurate and up to date. Similarly, the Sikorsky web site indicates that Sikorsky's alliance with FSI provides its S-92 commercial customers with the highest quality training available, with factory-approved curriculum for the helicopter at its Learning Center in West Palm Beach, Florida. Although Sikorsky does not actually approve the content of the S-92 Pilot Training Manual (PTM), Sikorsky pilots who take the S-92 ground school and simulator programs monitor the content, and provide recommendations for improvement to FSI. There is frequent contact between FSI and the Sikorsky customer service representative to address questions about training.
The recurrent ground training, including helicopter systems training, is taught referencing the FSI S-92A PTM and the S-92A RFM and consists of 22 hours of classroom instruction. An assessment of the course content was completed based on investigation interviews, a review of the FSI training module and a review of Chapter 10 of the PTM, which covers the S-92A powertrain.
The PTM powertrain chapter explains that lubrication of the MGB is through a dual lubrication pump system. The PTM includes a lubrication system schematic for the powertrain that depicts the dual lubrication pumps and a picture of the two external oil pumps mounted on the front of the powertrain. It also notes that if one pump should fail, the lubrication system can still supply sufficient lubrication; however, the pressure will drop to the lower green range (i.e., approximately 45 PSI). The PTM states that if both pumps should fail (loss of all lubrication), safe operation is still possible for a short period of time. There is no mention as to how long the gearbox would be able to continue operating, nor is there an identified recommended maximum time of continued safe operation, following a loss of lubricant in either the PTM or RFM.
The PTM is consistent with the RFM, part 2, section 1 with the exception of its explanation of the oil pressure sensing system. The PTM mentions that if the MGB oil pressure drops below 24 psi (sensed by the switch at the left accessory module) or 35 psi (measured by the pressure transducer in the input manifold), the red MGB OIL PRES warning message appears and a "gearbox pressure…gearbox pressure" audio sounds. However, the manufacturer has since clarified to the TSB that the information in the RFM is correct and that each sensor must independently record low oil pressure conditions; the transducer oil pressure must drop to 35 psi and the oil pressure at the left accessory module must decrease to 24 psi in order for the aural warning and the master warning to activate.
Other MGB components identified in the PTM include the chip detector, the oil temperature sensor, the MGB oil pressure switch, and the oil pressure sensor. The PTM does not include information regarding how the temperature gauge senses temperature (i.e., that it is a wet bulb requiring immersion in oil) or that it would be unreliable in the event of a total loss of oil, as it would, in such a case, measure ambient temperature inside the MGB case.

[SASless]

Interesting thought re the stud failures on the oil filter housing!

its laughable to consider the gearboxes/oil filter arrangement of the 92 versus UH60 as being one-in-the-same. For one thing, the filter on the 60 is mounted vertically, not cantilevered off the side of the MGB casting shaking on giant moment arm with the 1P.

[212man]

My understanding - which could be wrong - is that the baseline impurity levels for oil in the can is for larger particulates than the filter. Hence the nuisance bypass pop out indications and hence the reason 'some' (no names, no pack drill) operators use pre-filtering. As mentioned in the report.

It would be nice to know why more attention wasn't given to the electrical power loss. Was it a sudden Nr drop or AC GEN overheat - caused by loss of cooling oil? I think it's also a bit simplistic to say the AC Generators are engine driven, too. They are essentially MGB driven, and most certainly MGB oil cooled.

[SansAnhedral]

Interesting thought re the stud failures on the oil filter housing!

Yes, the hawk MGB oil filter is mounted vertically to the lower sump housing and is actually designed to be accessible from inside the cabin through the ceiling.

Here is everything you ever wanted to know about the UH60 drive system in a nice concise document with lots of pictures (note the explicit entry of "With a loss of all oil, the main XMSN will continue to operate in flight for another 30 minutes"):

http://aasf3-ny.org/4-Standards/Documents/PUBLICATIONS/StudentHandouts/UH60%20Powertrain%20and%20Rotor%20System.pdf

Look on the lower right
http://www.army.mil/-images/2009/04/16/35431/army.mil-35431-2009-04-16-150409.jpg


My understanding - which could be wrong - is that the baseline impurity levels for oil in the can is for larger particulates than the filter. Hence the nuisance bypass pop out indications and hence the reason 'some' (no names, no pack drill) operators use pre-filtering. As mentioned in the report.

This is absolutely the case.

[Lonewolf_50]

212, if the S-92 is similar to the Hawk series (S-70 derivatives) IIRC the main generators dropoff when Nr droops in the Nr = low 90's high 80's. (The number in my memory is 92% but that might not be right).
EDIT: Heh, :cool: memory is not all bad ... from the FCF checklist a few iterations ago ...

b. Underfrequency protection — Test.
(1) No. 1 and No. 2 PCLs — Retard slowly.
(2) #1 GEN and #2 GEN cautions — Appear between 92 and 97 percent Nr. Allow a 3-second time delay. Note Nr.
(3) No. 1 and No. 2 PCLs — FLY. Note #1 GEN and #2 GEN cautions disappear.


I think that in the Cougar mishap, the backup generator (powered by the APU) was up and running. That said, in the Hawk series, the switch over from #1 / #2 gen to Backup Gen powering the various AC and DC busses isn't what I'd call seamless. (TYpically SAS and AFCS kick off, though I don't think Boost would kick). I'll guess it isn't in the S-92. (I think this has been addressed both in this thread, and in the TSBoC report).

EDIT: More data that my memory isn't completely shot.



Power transfer from the APU generator or EXT PWR to the No. 1 generator may cause disengagement of SAS 1, SAS 2, TRIM, AUTO PLT, and stabilator.

SansAn ... thanks for the training manual, it restores a bit that was lost in memory. :cool:

[Lonewolf_50]

For SansAnhedral.

I can almost guarantee Ti studs were originally used for weight issues.

I am not so sure. Ti also has superior corrosion resistance, and if the S-92 was expected to be sold to maritime environment operators, that consideration (as well as dissimilar metal interface issues where the studs seat in the mag housing) may also have been a factor. At that order of magnitude, the weight of three Ti studs or Steel Studs looks negligible ... however, if as you say it was financially incentivized, perhaps the material selection was, for that reason, more heavily weighted than would otherwise have been the case. (Sorry for that poor pun :8). A lot of little fractions of a pound saved here and there add up to pounds saved from the transmission deck ... and thus not passed into the airframe via the xmission mount ... and so on.
During a period of time during work on the CH148 production modification SAC was willing to pay the engineering teams multiple thousands of dollars worth of engineering hours per pound saved...especially from the dynamic system. The 92 was seemingly perpetually overweight.

Every helicopter does the weight battle for that ten pounds here and the fifty pounds there during design, does it not? It's a never ending battle and series of compromises.

FWIW, I don't see the oil filter bowl as part of the dynamic system ... I see from the swashplate to the ends of the rotor blades as the dynamic system, but perhaps I misunderstand what you are referring to there. Are you referring to "the dynamic system" as being that load of stuff mounted to the transmission deck, and thus vibrating as soon as the rotors start to turn? :confused:
And its laughable to consider the gearboxes/oil filter arrangement of the 92 versus UH60 as being one-in-the-same.
For one thing, the filter on the 60 is mounted vertically, not cantilevered off the side of the MGB casting shaking on giant moment arm with the 1P.

I think the term you seek is "one and the same" but I caught your drift. :)



shaking on giant moment arm with the 1P

"Giant?" (do you mean that in reference to the cross section of the bolt?)
and why the 1P rather than the 4P? :confused:

I agree with your point on the stress analysis having to consider vibration and loads differently than with the sump mounted filter in the Hawk series ... :cool:

[SansAnhedral]

Lone,

Yes you got me with the 4P. And at SAC, "dynamic systems" is hubs, blades, xmsn...basically all components of the rotor system.

[squib66]

Aux tanks: I personally can't see either the tanks or the sector length having an effect on the filter studs.

Filter removals: This seems a bigger potential factor. Sadly it is not possible from the information presented to determine if the CHC and Cougar filter removals (particularly on the two aircraft that had oil oss in flight) was significantly worse than other operators.

Oil filtering: 212man, yes perhaps some operators choose to pre-filter their oil. However if that was essential it shuld have been in the Maintnance Manual!

Titanium: No matter what reason, gaulling makes titanium a poor material choice and this should have been considered in the FMEA.

Part 29.927(c)(1) Design Assessment FMEAs: As Sikosky failed to even consider the oil loss from the filter housing (see below) it is no surprise thatneither was the material choice challenged or recoconsidered when service experience showed high filter removal rates (and so high gaulling potential)/

Neither the FAA nor Sikorsky specifically considered a failure in the MGB oil filter bowl assembly, or its attaching fasteners, in the context of Part 29.927(c)(1).

Studs are critical: Two events of oil loss now show that the studs are what FAR29 defines as 'Critical Parts', irrespective of what material they are. AFAIK they are still not subject to the enhanced critical parts control regieme required by FAR29 for such parts.

Social media: My reading of the TSB report is that they are implying that they believe that contributors to a certain forum did understand the situation but TSB aren't necessarily claiming that contributors actually wrote what they understood.

Blackhawks: Great info guys! A contact in Australian Army tells me that their aircraft have steel bolts (not studs) - highlighting another difference. If the US Army documents are correct in saying the its MGB can operate for 30 minutes without oil then the S-92 is a massive retrograde step and by no means the wonder that some made it oput to be.

[Lonewolf_50]

Sans, thanks, "dynamic systems" being all them things moving ... like gears and shafts. :ok:

[Lonewolf_50]

Aux tanks: I personally can't see either the tanks or the sector length having an effect on the filter studs.
Vibration's a funny thing, with sometimes nonlinear effects ... but who would have required an analysis during design of "filter bowl vibe/wear if the torque on the nuts isn't right?" The simple answer to that is "Torque it properly and it won't be an issue." :cool:

Oil filtering: 212man, yes perhaps some operators choose to pre-filter their oil. However if that was essential it shuld have been in the Maintnance Manual!

Whose maintenance manual: operator or manufacturer? The decision on how much impact/nuisance/trouble a clogged bowl or popped filter button represents isn't the manufacturer, it's the operator. Pre filtering seems to me an operational decision made based on the number of sorties/missions/trips/legs lost due to such events balanced against typical leg/sortie/mission/trip general factors: over land? Over mountains? Over sea? Twenty minute leg? Two hour leg?

The Manufacturer might not be the best at assessing this for a given operator. Given the variability of oil suppliers, any operator may have
a) best supplier, and no need to filter
b) variable suppliers, and maybe a standing need to filter
Titanium: No matter what reason, gaulling makes titanium a poor material choice and this should have been considered in the FMEA.

Given the cost alone it might have raised an eyebrow ... unless lots of them are used for a variety of applications in numerous production aircraft? :confused: Don't know.

Studs are critical: Two events of oil loss now show that the studs are what FAR29 defines as 'Critical Parts', irrespective of what material they are. AFAIK they are still not subject to the enhanced critical parts control regieme required by FAR29 for such parts.

It was very instructive (and in hindsight, tooth gritting) to see the TSB analysis of the decision chains after the incident in Australia and before the Cougar mishap.
Blackhawks: Great info guys! A contact in Australian Army tells me that their aircraft have steel bolts (not studs) - highlighting another difference. If the US Army documents are correct in saying the its MGB can operate for 30 minutes without oil then the S-92 is a massive retrograde step and by no means the wonder that some made it oput to be.
I recall some talk (late 90's) that perhaps once S-92 was fielded, its transmission could be backfitted to some of the SH-60 models and allow greater advantage to be taken of the power available from the engines ... acft being torque limited in two eng operation ...

[zalt]

L_50, in fact HEEDS is now in use for passenegers flying out of St Johns. It took 6+ years to introduce and had been stalled up until after the accident.

HC, yes Rick Burt left for Australia in the middle of lasy year. I don't know why, but the travelling from home in BC to NL and the Inquiry appreances after the accident must have been a strain.

[Jack Carson]

Initially the S-92 was conceived as a large cabin Superhawk, with a gross weight of 22220 lbs. The gear boxes and dynamic components of the S-92 were conceptually designed to be utilized on future upgraded versions of the H-60. As such, the baseline designs began with current, at the time, H-60 components. At the time, Sikorsky already had operational data from more than 2,000,000 H-60 flight hours. As the S-92’s gross weight increased, changes were made to the system. Two of those changes were to increase rotor speed from 258 RPM to 271 RPM (>5%) and to increase in main rotor diameter (53.66 ft. to 56.3 ft.). These changes combined to provide some of the additional lift required for the higher gross weight. I have to believe that MGB vibratory signatures changed from those historically seen on the H-60.

Additionally, system changes were made to provide for better maintainability/supportability. The location of the oil filter assemblies were relocated to allow for servicing from the top rather than from inside the cabin.

[zalt]

Two of those changes were to increase rotor speed from 258 RPM to 271 RPM (>5%) and to increase in main rotor diameter (53.66 ft. to 56.3 ft.).

Jack

Do you know when those changes were introduced into the design?

[Brian Abraham]

Power transfer from the APU generator or EXT PWR to the No. 1 generator may cause disengagement of SAS 1, SAS 2, TRIM, AUTO PLT, and stabilator.I'm guessing the possible loss of SAS perhaps went unnoticed in the heat of the moment, and again perhaps, explain the large pitch and roll excursions. 212man or other drivers care to comment.

[Jack Carson]

Zalt,
As near as I can recall, the following is a trail of the weight increases through the life of the program.

1993 – 22220 lbs.
1995 – 24100 lbs.
1998 – 25200 lbs.
2001 – 26150 lbs.

Sometime after that the weight continued to increase to 26500. The latest came with a change in the fuel system that increased the amount of usable fuel.

With respect to Brian’s concerns with generator under frequency, a circuit through the weight on wheels (WOW) switch inhibits the generator under frequency protection while in flight. However, there is no protection for generator under voltage. The generators will drop off the line at some lower rotor speed. I believe that you would have to reduce the rotor speed to approximately 80% or less.

[IsKan]

Finish reading the TSB report before asking all these questions and to speculate to much.

Plenty of good info in there. For them who post here, fly the SK-92 you should be looking into your company maintenance and ask if they wore following the right maintenance procedure issued by Sikorsky following the Australia incident. Also be sure you know your systems.

Many loose ends led to this, ask more where we sit now and what can be done in the future more than just not fly over rough water with out your helmet on.

[Lonewolf_50]

I'm guessing the possible loss of SAS perhaps went unnoticed in the heat of the moment, and again perhaps, explain the large pitch and roll excursions. 212man or other drivers care to comment.
Brian, I am making an assumption (possibly incorrect) that the AFCS similarities between S-92 and the various Hawks are sufficient that similar loss of flight control quality would be experienced if the generators dropped off line.

As to undervoltage vs underfreq, good catch, Jack, my memory isn't as good as I thought. I think the Hawk WoW switch functions as you state.

[squib66]

Is it true that the Canadian MHP / Cyclone / S-92F will have to pass the conventional "30 mins with loss of lubricant test" for acceptance into service?

[SansAnhedral]

Is it true that the Canadian MHP / Cyclone / S-92F will have to pass the conventional "30 mins with loss of lubricant test" for acceptance into service?

Well thats the $64,000 question. The original contract for CH148 stated a 30 minute run dry requirement pretty clearly. However it also stated flatly there would be fines, penalties, etc for a late delivery (by the day) and we all know what has happed with that.

Im betting some of the R&D time and money spent on the 5 bladed 92 head for VXX/CSARX could have better been spent on completing the IDMGB, which is supposed to be the catch-all solution for Canada and the S92A fleet.

Though when you can shoestring the Canadian MoD along for 3 years after the delivery deadline because you know they desperately need an AC, you end up with a nice source of supplemental S92 R&D funding you didnt otherwise have available.

[chw]

I bet the draft report would be very interesting to read (the one before all the snake oil sales man had they're influence ). :(

Los of all oil out of a gear box is a very isolated occurrence, after fixing the oil filter housing installation the Sk 92 has as much chance of losing all its transmission oil as any other helicopter model some would have a lot more chances of losing they're transmission oil due to the many and/or longer external oil lines.

Blaming the pilot for not understanding the aircraft's MGB pressure system is a disservice to the industry, maybe the presentation on the MFD is the problem .

Make the transmission oil pressure Caution and Warning display the source like X for transducer and S for switch and leave them both displayed when the pressure drops below they're set level.:ok:

It appears that Cougar spent lots of money on training they're crews so why did the crew lack understanding? Should the SK provide manuals be reviewed.
You Just do not land a Helicopter in the Atlantic with out a clear indication.

The emphases in the report is on survival after a successfully landing on the Atlantic Ocean not on avoiding it.

Comment in a leading Canadian helicopter magazine by some one claiming he flew 80 different type of helicopter are very disappointing. One can not be "flying" a helicopter by just studying a check list (such a pilot is called a passenger).:confused:

Can some one help me out here concerning page 130 , 2.7.94
"with out an ELT signal not being received ....SAR sources not being launched in a timely manner"
Was it not that SAR was very quickly launched be cause of Superior satellite position reporting system employed by Cougar helicopters.

Is it not that the Crash has been caused by design engineering practice of saving weight at the wrong place ( a few grams), than after the design we load the aircraft up with safety equipment (300.000 gram +) that has not been needed for 30 + years and at the end only saved one person. All other offshore crashes on the east coast did not needed any of the safety equipment other than the raft.

Howe much super cold oil do we need to inject in to the XMSN to keep flying until the helicopter can be landed at a better place than the Atlantic Ocean.

Does any one knows how many successful landing have been made at gusting wind to 35 Knots waves at 2.5 meters on the Atlantic Ocean?

Is a twin rotor helicopter a inherently safer design, no tail rotor 25 % of power not wasted, power shared by two transmissions , does it have a less critical CG?:sad:

Last but not least check out the net concerning "Proven designs" suggested as better alternatives to the SK 92. ( Eurocopter AS 332 notable accidents and incidents):eek:

[zalt]

Helicopter crash widow speaks out - Local - News - The Telegram (http://www.thetelegram.com/News/Local/2011-02-19/article-2256131/Helicopter-crash-widow-speaks-out/1)

Helicopter crash widow speaks out
'This was preventable' says Lori Chynn

For Lori Chynn, the crash of Cougar Flight 491 is about the two small, titanium studs that sheared off as the helicopter flew to the Grand Banks oilfields on the morning of March 12, 2009.

Her husband, White Rose medic John Pelley, was among the 17 people who died when the helicopter crashed and sank into the North Atlantic.

Chynn describes the broken bolts as the root cause of the crash, and says inspecting and replacing them would have prevented the tragedy.

“That’s the part that’s so hard to hear — that this was preventable,” she said.

“I just feel that if the helicopter was not in the air this would not have happened.

“It shouldn’t have been in the air. The studs should have been replaced right away.”

Chynn has closely followed the Transportation Safety Board (TSB) investigation of the crash and took part in the helicopter safety inquiry led by commissioner Robert Wells.

“My husband was a very outspoken person and he stood up for what he believed in.

“So, I feel that each time something comes out he has to have a voice. That’s very important.”

More than a week ago, Chynn listened as TSB officials outlined their investigation report to the families of passengers killed in the crash.

They were briefed on its contents at a separate location before the report was released to the media. TSB officials stayed with the families for more than four hours, answering their questions.

Chynn said one thing missing from the briefing was an opportunity to hear the publicly released portion of communications between the Flight 491 pilots and Gander air traffic control.

“They provided a very good, safe place to come and go and ask questions. Why did they not provide the same opportunity with that?”

“Why weren’t we given the opportunity to hear this, if we wanted to?”

She would have preferred to hear what was released before it aired on television.

“I wasn’t expecting this to come on the news and when it did it really unnerved me,” she said. “It was an awful feeling to hear. It was very haunting.”

But it doesn’t change her mind about the cause of the crash.

“I believe the pilots did the best that they could. They wanted to come home to their families, too.”

The TSB said two of three titanium studs failed in flight, resulting in a complete loss of oil from the main gearbox that powers the helicopter.

Since the crash, Sikorsky S-92 helicopters use stronger steel studs, and six studs now secure the oil filter bowl to the main gearbox.

The TSB report outlined what it called a complex web of 16 factors that contributed to the crash. And agency officials said taking one or two of those factors out of the web might have prevented the crash.

Chynn sees it a little differently.

The detailed TSB report clarified many things, but she isn’t entirely satisfied with it. She doesn’t see all 16 contributing factors as equal.

“I just feel that there wasn’t enough emphasis put on the root cause … the studs,” she said. “That’s the cause of the accident.”

Chynn said the TSB report did help her understand the notion of a 30-minute run dry capability for helicopters — a test the Sikorsky S-92 failed during certification by the U.S. Federal Aviation Administration (FAA).

Dry run refers to how long a helicopter can continue to fly after losing all oil from its main gearbox.

U.S. regulations require 30 minutes of flying time unless failure of the oil lubricating system is shown to be “extremely remote” — as was the case with the S-92.

The TSB report recommended that aviation regulators — FAA, Transport Canada and the European Aviation Safety Agency — reconsider the way they certify helicopters.

It recommended the FAA remove the “extremely remote” provision from the 30-minute run dry rule.

The TSB also said 30 minutes may not be sufficient when flying long distances over water — recommending regulators review its adequacy.

Chynn believes the S-92 should be thoroughly evaluated to make sure it’s up to the job of safely transporting people to and from the province’s oilfields.

“Is this the right helicopter to be going over the North Atlantic?“The bottom line here is, safety for offshore workers — the same as safety for any worker.

“We need to learn from this how to make our offshore workers safer — bottom line — at whatever cost.

“I don’t ever want any other family to have to go through this … the recommendations need to be followed through.

“Whatever has to be done has to be done.”


mbaird at thetelegram.com

[Winnie]

Not to diminish the voice of the widow, but was not the same things said about the S-61 in the early 70's??

I lost my godfather to the one crash in Norway in 76 (Might have been 77) that Killed all aboard. That was the 3rd accident of its kind too, loss of one blade. The 61 is now renowned for its safety...

SK never wanted this to happen, and they are working on it, and hopefully they will find a solution (I.e. dry run), but it has to be said, that systems knowledge might have helped.

Regards
Hagar.

[Lonewolf_50]

Response to chw.
Blaming the pilot for not understanding the aircraft's MGB pressure system is a disservice to the industry, maybe the presentation on the MFD is the problem .

I don't think you understand, and it has nothing to do with "the industry" being offered a disservice. And it's the lubrication system that the board felt the pilots may not have understood thoroughly enough, not just oil pressure and pumping.

Aside: Your maybe has been addressed in some detail in the report, and in the discussion for the last few pages on this forum. Maybe, and maybe not, on the MFD being where one addresses this problem. If you have not read this thread since its inception, you have missed some bickering, but also some very thoughtful input from experienced pilots on pros and cons of S-92 operations, and over water operations.

The blame for what is presented in the report as pilot unfamiliarity with how the lubrication system works, and thus the estimate of the impact this had on the trouble shooting and decision making by the crew, is a correctly pointed finger at the training manuals and flight manuals, and thus overall the pilot training program that influenced this crew.

Please go up a bit and see where I posted a (roughly) twenty year old warning from the Seahawk NATOPS manual that explicitly points out the wet bulb temp may not be telling you the truth is you lose your oil. I understand from this extended discussion that the Hawk transmissions and the S-92 transmission have that feature in common. Therefore, for this feature of a system to not be addressed in training is either a dumbing down of training, an oversight, or something even worse: an attempt to train helicopter pilots to be Pavlovian dogs (respond to the light!) rather than aviators who know their aircraft inside and out.

I was taught at a very early stage in my flying career that you have to know your aircraft inside and out ... as I began to fly helicopters, that requirement was made with even greater emphasis. Saved me life, it did.
It appears that Cougar spent lots of money on training they're crews so why did the crew lack understanding? Should the SK provide manuals be reviewed.
See above. It isn't the money, per se, it is how it's spent. I have some questions about your familiarity with pilot training. How much experience do you have as an instructor or trainer of aviators?
You Just do not land a Helicopter in the Atlantic with out a clear indication.
I find the less glib explanation of the board superior to your soundbyte, and your "Pavlov's Dog" attitude in re pilots. However, I tend to agree with your general idea that ditching is not to be casually approached, particularly in the dangerous seas confronting that crew. You go from one dangerous situation to another.
The emphases in the report is on survival after a successfully landing on the Atlantic Ocean not on avoiding it.

Really? Given that
the operational environment of that mishap was powerfully influenced by the hostile sea, rather than the calm, warm waters of the Caribbean (for example)
and that
Canada has coastal operations in very dangerous and cold waters,
maybe their investigation into "are we addressing the environmental risks of our operations (collectively)" is precisely what the Canadian aviation community would hope to have them address in some depth ... as well as some of their other points raised in re material and crew issues.
It does you no good to survive the crash and then die in the environment, I think you'll agree. I was taught that rather forecefully in the US Navy training I got.
Is it not that the Crash has been caused by design engineering practice of saving weight at the wrong place ( a few grams), than after the design we load the aircraft up with safety equipment (300.000 gram +) that has not been needed for 30 + years and at the end only saved one person. All other offshore crashes on the east coast did not needed any of the safety equipment other than the raft.

Incoherent, what do you actually mean by this? The person saved is grateful, I am sure, as is his family.
Howe much super cold oil do we need to inject in to the XMSN to keep flying until the helicopter can be landed at a better place than the Atlantic Ocean.

How much weight do you want to add to the transmission deck? Why do you want to refrigerate the oil? How much time have you spent flying helicopters? Your question makes little sense to me.
Is a twin rotor helicopter a inherently safer design, no tail rotor 25 % of power not wasted, power shared by two transmissions , does it have a less critical CG?http://images.ibsrv.net/ibsrv/res/src:www.pprune.org/get/images/smilies/puppy_dog_eyes.gif
Where does your 25% figure come from?
Is it your opinion that no helicopter should have a tail rotor?

[Thomas coupling]

Interestingly, the investigators deemed it appropriate to comment thus:

1.18.6 Social Media
The internet has greatly increased opportunities for individuals to interact and exchange information and viewpoints. Internet forums, a form of social media,139 have become a widely popular source of information exchange. On one such internet forum, the S-92A generated an enormous amount of discussion. Starting in March 2000, before the S-92A went into commercial use, website visitors engaged in discussions about the introduction of the S-92A. Many of the individuals who posted on this website chose to remain anonymous. However, others such as one of Sikorsky's senior managers for the S-92A program, who was a regular contributor to the online discussion, chose to identify themselves. Over the course of several years, the subject of the S-92A's compliance with Part 29 was discussed at length among members of this internet forum. From these online discussions, it was evident that those involved understood that the S-92A did not have a run dry capability.

It was determined during the TSB investigation that at least one senior manager, and several other pilots at Cougar Helicopters periodically reviewed the material posted on the above mentioned internet forum.

Social media content such as internet forums can also be useful in judging cultural beliefs within a specific group such as helicopter pilots. For instance, some visitors indicated that the discussions mentioned above caused them to review the run dry capabilities, if any, of the helicopters they were flying. The online discussions also seemed to indicate that the typical offshore pilot would continue flight toward shore rather than ditching, no matter what the checklist said, until they were confronted with secondary indications that the transmission was about to fail catastrophically.

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

The report raises a lot of heartache for those responsible for the cause of the crash, aircraft manufacturers, operators, aircrew.
It is absolutely essential that the content of this report is not lost in time and that everyone who is a shareholder in the industry, inwardly digests and learns from such a tragedy, so that we minimise future losses.

That, perhaps, is the beauty of Pprune............

[zalt]

Has TSB failednto analyse tehcrew decision probably.

TSB gave short shrift to key infoBy LOUIS DESJARDINS

Cougar Helicopters Flight 91 lost oil pressure during a flight from St. John's to the Hibernia SeaRose oil platform almost two years ago. The Sikorsky S-92 (a version of which is on order for our armed forces) was approximately 20 minutes from shore when the pilot turned back. Tragically, 17 people died when the chopper crashed into the Atlantic Ocean some 11 minutes later.

Cougar launched a lawsuit against Sikorsky Aircraft in part because they had advertised that the S-92 was able to continue operating for half an hour after losing oil pressure.

However, our Transportation Safety Board's review of the accident said that neither the pilot nor the co-pilot would have thought this to be the case because they did not "make a comment" to that effect while trying to determine their best course of action.

But would they have found it necessary to comment on something if both believed it were so? Is it not just as likely that their decision on whether to ditch or head for shore was influenced by Sikorsky marketing's original claim that the craft could operate for 30 minutes on residual oil?

Or perhaps the claim, after tests showed that the first claim was untrue, that a feature of the S-92 was "thirty minutes safe operation following an oil leak"? The TSB gave very short shrift to what may well have been a very large factor in the calamity...

TSB gave short shrift to key info - Belleville Intelligencer - Ontario, CA (http://www.intelligencer.ca/ArticleDisplay.aspx?e=2987935)

[Hedge36]

I disagree. The copilot made multiple attempts to convince the captain that they were at the ditching point of the checklist. It seems to me that if the captain was truly under the impression that he had a 30 minute window, he would have said something along those lines to refute the copilot's assertion that it was time to ready the ship for water. If the copilot, who seemed the more verbose of the two, thought they had a 30 minute window, I'd have to think HE would have said something about it.

I'm not sure what Mr. Desjardins is really after here.

[zalt]

The co-pilot was not verbose - look at the graph is the TSB report.
http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/a09a0016/images/a09a0016_figure_9.gif

[Pilot DAR]

In reviewing a number of helicopter flight manuals, and considering what I would do under the various circumstances, I recall the two written phrases: "Land immediately" relative to "Land as soon as possible". One flight manual defined "Land as soon as possible" but referred to "Land immediately" as being "self evident". I'm no so sure I agree....

"Land" suggests the pilot is to take action which would result in returning to earth both safely, and with the expectation of little or no damage to the helicopter. Isn't anything less, a "Crash", as compared to a "Landing"? I have not seen a flight manual which says: "Crash immediately"....

I think that a pilot has the right to expect that his aircraft is not likely to further deteriorate during his attempt to get down with little damage or risk, "land". Yes, the worst can happen, but the design standards do define a number of intended safeguards, to give that margin of safety and time. A 30 minute run dry sound like one to me.

I opine that the flight manual statement "Land immediately" should be ammended to also say "... and crash if you have to", if that's the reality of the situation. Let's call it what is is!

If things are still turning under power, and control is still available, it is really asking a lot of the pilot to give up the possibility of a "landing", to just crash. It's hard to explain that to the boss - "the X light flickered, so I crashed your umpteen million dollar helicopter". I equate it to ejecting. I have never been trained to eject, or otherwise give up on flying. I have been trained to land - normally, precautionary, or forced, as the case may be. I accept that some military aircraft are well served by the provision for the crew to eject. I do not think that civil use aircraft would benefit from this provision.

I think our industry must provide aircraft, which can be "landed" under all but the most dire circumstances. We then need to train pilots when they must "land". "Immediately", should not be a part of that. Unless you're on approach to the perfect surface, you should feel confident that you can use some judgement, and have a few minutes, to select a place where you might land, rather than crash. If the helicopter is going to crash, because the turning has stopped, or control is impossible, the pilot just became a passenger, and is relieved of the responsibility of flying, otherwise, he should get to fly....

[zalt]

I opine that the flight manual statement "Land immediately" should be ammended to also say "... and crash if you have to", if that's the reality of the situation. Let's call it what is is!



Land doesn't mean on land...

From the TSB:

In helicopter operations, "land immediately" is considered the highest priority emergency situation, and it is generally accepted as representing imminent danger to the crew and passengers. To illustrate, two definitions are provided from similar-sized military helicopters operated off the East and West coasts of Canada.

CH-124 Sea King:

Land immediately - an immediate landing/ditching is mandatory. The consequences of continued flight are more hazardous than those of landing at a site normally considered unsuitable.

CH-149 Cormorant:

Land Immediately - Imminent danger exists. An immediate landing/ditching shall be made in order to prevent loss of life.

In the S-92A RFM and Pilot Checklist utilized by Cougar Helicopters, "land as soon as possible" and "land immediately" are defined as follows:

Land As Soon As Possible - Land at the nearest site where a safe landing can be accomplished.

Land Immediately - Continued flight may not be possible. Ditching or landing in hazardous terrain is preferable to continuing flight.

[Pilot DAR]

I stand informed. Those definitions seem unambiguous, and that's great. I have not had the occasion to fly such larger helicopters. Hopefully lighter helicopters will adopt those seemingly appropriate definitions in the future.

I will always recall doing my confined area training in the SW300, and getting the inevitable caution light from the instructor as I picked up. He seemed surprized when I did not put it right back down in the area, but rather continued back to base a mile away. I explained when questioned that I dicided on the spur of the moment, that on a perfect flying day, I could make it the mile with an unserviceable alternator, rather than shut down in a hole, and hike out. Next time he pressed the transmission chip warning light instead....

[Brian Abraham]

Land Immediately - Continued flight may not be possible. Ditching or landing in hazardous terrain is preferable to continuing flight.zalt, to me the 92 seems to suggest by the use of the words may and preferable that the crew may have some scope for using judgment. ie
Continued flight may not be possibleContinued flight may be possible then? The wording is a little wishy washy to me, completely unlike your Sea King and Cormorant examples, as in,an immediate landing/ditching is mandatory.andImminent danger exists. An immediate landing/ditching shall be made in order to prevent loss of life.No scope there for any doubt what is being said. Perhaps it's just me, but offer up the suggestion for the forums consideration.

[Thomas coupling]

C'mon Brian: we all know what each means don't we. Let's not beat about the bush. There is no room for interpretation here.
What happened on that dark cold night was that the Captain of that a/c heard the words: land immediately but convinced himself that this would all be OK and physically flying his currently "flyable" helicopter into a bitterly cold wet place surely could wait a little longer. He stretched it and stretched it....he went into denial hoping to glimpse land.
It's all very well nodding and agreeing to what land immediately means in the warmth of the cre room or in the sim....but for real....an individuals psychology comes into play.
What 'may' have cleared the fog of judgement making would perhaps have been a better understanding of what exactly was going on in his gearbox!
RIP.

[Mel Effluent]

I have dug out the relevant passage from an ancient set of Flight Reference Cards for a UK military helicopter, which reads as follows:

The Urgency of the Need to Land

Following a system failure, it may be necessary to land the aircraft for safety considerations. The degree of urgency to land the aircraft depends on the nature of the failure and the prevailing conditions. The following terms are used to give guidance on the degree of urgency required but are not intended to be precise definitions:

Land Immediately

Land at once even if, for example, the outcome is ditching or landing in trees. The consequences of continued flight are likely to be more hazardous than those of landing at a site normally considered to be unsuitable.

Land As Soon As Possible

Do not continue flight for longer than is necessary to accomplish a safe but unhurried landing at the nearest site.

Land As Soon As Practicable

Land at the nearest aviation location or, if one is not reasonably close, at a safe landing site selected for subsequent convenience.

Overall, I think that this is a sensible approach as it does not mandate the crew's actions in advance. Whoever drafts and approves the emergency checklist cannot possibly foresee all the potential situations and ultimately, it should be the captain's decision what to do.

Tragically, in this case, the decision to continue flying was flawed, but we will never accurately know what the crew's assessement of their situation was, though I suspect that the pilots' mental models were significantly different. Personally, I am profoundly grateful that I have never been put in a similar position, even though I have speculated on what I would do if presented with a 'Land Immediately' situation do many times. Risk management in aviation is not a simple linear process and how many of us can claim that we make perfect decisions every time?

RIP

[SASless]

Way back in the early days of the thread I offered up my htoughts on the mindset of continuing to fly until we hear ugly noises then ditch. I acknowledged having been of that persuasion for most my career having flown over some very inhospitable terrain or very unfriendly folks. I also suggested this was a common attitude amongst helicopter pilots.

It took this tragedy to disabuse me of that notion.

It also refreshed my concern about flying over such terrain in weather conditions that made such forced landings so dangerous.

When I heard the Captain make his intentions known to ATC.....knowing the actual outcome of the event....made me sit back and consider how lucky I have been in the past on a couple of occasions when guilty of the same thing.

No doubt there are others posting here that know they too have escaped from that flawed logic and its potentially catastrophic outcome.

I presume few of us hold to that mindset today as a result of the Cougar crash.....that is a postive outcome out of this tragedy.

Ernie Gann in "Fate Is The Hunter" discusses this very aptly.

[Lonewolf_50]

I opine that the flight manual statement "Land immediately" should be ammended to also say "... and crash if you have to", if that's the reality of the situation. Let's call it what is is!

While this has been previously addressed, I think the idea of "land" immediately is to avoid "crash" at a point in time later.

Ditch = land on the water in a controlled manner, rather than "crash" into the water.

Cheers.

[maxwelg2]

What happened on that dark cold night was that the Captain of that a/c heard the words: land immediately but convinced himself that this would all be OK and physically flying his currently "flyable" helicopter into a bitterly cold wet place surely could wait a little longer. He stretched it and stretched it....he went into denial hoping to glimpse land.



For clarification it was daylight flying and the SS was right on the limit @ 2.5 metres, CGR491 had SS4 floats installed even though SAC pitched these as SS5.

PIC wasn't aware of wet temperature bulb issue, checklist was too vague in getting to land immediately status (should have been a memory item).

No secondary indications of MRGB issue so PIC carried on flying back to land i.e. land as soon as possible. If PIC was aware of these issues I honestly believe he would have ditched. They tried their best too late once the T/R drive failed on them.

We can point fingers of blame at many factors as the TSB report quite rightly has i.e. SAC, FAA, and even Cougar for not picking up on the galled studs during filter changeout. It's not bringing anybody back.

All we can do is try and prevent this happening again, that's why one of the widows of 491 wants answers on the studs and an explanation for the lack of effective response to the Broome 2008 stud failure. How on earth the botch repair job to the Broome stud prior to failure was even approved by SAC stuns me never mind how they then dealt with the issue. SAC will no doubt try to cover themselves with the AMM but the proper action would have been change the studs immediately. For me that is gross negligance and SAC should be held accountable to the full extent of the law.

30-minute run-dry should be a given in our environment, not a work-around. SAC have let us all down here.

Safe flying

Max

[212man]

II,
Are you 100% sure of that? Others on this board may disagree! It's a fact though that The bodged repair didn't fail - the two other studs failed! However, the repair led to a perception that dictated the urgency of the ASB......

[maxwelg2]

II, from the TSB report the SAC rep did not disapprove so by virtue of consultation and no objection IMO accepted the repair.

VH-LOH's MGB oil filter bowl had been removed and reinstalled 17 times during the helicopter's total time in service (1233.4 hours). Approximately 58 flight hours before the July 2008 incident, on 09 June 2008, a MGB oil filter bowl mounting stud had fractured during removal of the attachment nut. Because a new stud and the proper tools were not immediately available, after consulting with Sikorsky's local field service representative, CHC carried out a temporary repair, installing a self-locking nut on the fractured stud. The self-locking feature of this nut did not fully engage the shortened length of the fractured stud so a hole was drilled in the nut to lockwire it for security. Although Sikorsky's engineering department was not specifically consulted, no technical objections to the temporary repair were presented by the Sikorsky field service representative.

212man, from section 2.1 of the Waldron report the "repaired" stub with the Nyloc nut was one of the failed studs.

VH-LOH was in the air for only 5 minutes from MRGB pressure loss and not as the local media stated the other day flown until the MRGB failed. I wish they would get their facts right.

Safe flying

Max

[maxwelg2]

II, are you implying that the TSB mis-read the Waldron report and/or is there another version of this report, the one I have I got from CBC's 5th estate website a while ago?

Section 4.21 of the report states that two of the studs were mis-labeled, perhaps that is where the confusion exists.

Section 4.3.1 of the report states that the top stub was the one that had previously failed and had the Nyloc nut fitted. This stud was definitely one of the broken ones according to the report.

Section 4.5.1 states that the lower forward stud was the one that didn't fracture.

On 491 the top stud was the only one not to have fractured.

The TSB went to lengths to describe the Broome incident:

In the Australian occurrence the helicopter was not damaged and there were no injuries. The failure initially appeared to have been related to an isolated field repair. Sikorsky advised its customers of these early findings and also suggested that extra attention be given to the filter bowl fasteners.

After an independent engineering firm flagged galling as a possibility on the titanium studs, Sikorsky completed a safety review of the Australian accident and the failed studs. Sikorsky and the FAA came to understand that the source of the problem was in fact galling. Sikorsky, utilizing a risk management process, made an assessment of the Australian occurrence flight, noting that it was able to continue flight for several minutes following the loss of lubricant without causing serious damage to the helicopter. Based on this assessment, Sikorsky developed its safety action, which the FAA accepted. SSA-S-92A-08-007 was communicated on 08 October 2008 to alert operators of the upcoming AMM Revision 13. These mandatory enhanced inspection requirements aimed to ensure damaged studs would be detected and removed.

Believing that the mandatory enhanced maintenance procedures would mitigate risk to acceptable levels, Sikorsky established a compliance time to the Alert Service Bulletin for the replacement of the titanium studs of one year or 1250 flight hours.

As of 05 November 2008 (date of issue of AMM Revision 13), Sikorsky had not received any reports of damaged MGB oil filter bowl attachment studs. Therefore, all of the S-92A helicopters in service at that time (except VH-LOH) would have been equipped with the original MGB oil filter bowl attachment studs. These studs would have had the nuts installed and removed a minimum of 3 times and, in helicopters with similar flight hours as the occurrence helicopter, the nuts would have been installed and removed over 10 times.

The TSB's examination of new S-92A MGB studs and nuts, similar to the type used on the occurrence helicopter, showed that galling damage developed during the first installation of the nut and became progressively worse with repeated installations. The galling was further exacerbated when the nut was reused. AD 2009-07-53 was issued on 23 March 2009, about 5 months after AMM Revision 13. During this 5 month period, every time the MGB oil filter was changed, it was mandatory for operators to carry out the enhanced inspection and to replace any damaged studs.

After AD 2009-07-53 had been issued, Sikorsky requested that operators return the studs they had removed to comply with the AD. As operators were under no obligation to comply with the request, Sikorsky only received a total of 59 studs from various operators. All of these studs, as well as the studs recovered from the occurrence helicopter and the other Cougar helicopters, had different severities of galling, which would be consistent with a difference in the number of times the nut was installed and removed. Based on the S-92A fleet average monthly flying hours, and the average time between MGB oil filter replacements, it is likely that most, if not all, of the 59 studs returned to Sikorsky would have been subject to inspection at least once during that period.

Since the thread galling was detectable using the new procedures, and given that no damage was reported and that there were no reported problems complying with the enhanced inspection procedure, it must be concluded that most S-92A operators, including Cougar Helicopters, did not implement the new maintenance procedure as specified by AMM Revision 13 and, therefore, damaged studs on the filter bowl assembly were not detected or replaced. As these maintenance procedures were mandatory, the low compliance rate can perhaps be attributed to the possibility that operators did not clearly understand the underlying reasons behind the enhanced procedures and the need to detect and replace damaged studs. That is, they did not appreciate that a failed MGB filter bowl assembly mounting stud would cause an uncontrolled total loss of MGB oil that would eventually lead to the failure of the MGB

To me this reads like SAC is pointing the finger at the operators by placing the onus on them via non-implementation of the AMM. Why would SAC not compare the historical Blackhawk steel stud performance to the S92 titanium studs and immediately realize that there was a material issue as part of their risk analysis process?

I still say that SAC is at fault here for being grossly negligent, JMHO.

Safe flying

Max

[Brian Abraham]

C'mon Brian: we all know what each means don't we. Let's not beat about the bush. There is no room for interpretation here.In the comfort of our lounge room chairs, yes we do as you noted. But that knowledge doesn't explain why on so many occasions the instructions are not complied with. Note the previous Norwegian 92 episode and SASs honest comments, and that's beside the many pilots surveyed who said they would have continued as well. I must ask, have you ever been placed in a similar situation? SAS has, and so have I. Pity there is not someone with a background in psychiatry who could contribute some practical understanding of decision making in extremist situations.

SAS, indeed fate is the hunter, and some of us are blessed to be still around to ponder our good fortune. RIP Jerry Hardy.

[Outwest]

To me this reads like SAC is pointing the finger at the operators by placing the onus on them via non-implementation of the AMM. Why would SAC not compare the historical Blackhawk steel stud performance to the S92 titanium studs and immediately realize that there was a material issue as part of their risk analysis process?

I still say that SAC is at fault here for being grossly negligent, JMHO.

Of course they are, but the blame also must lie with the FAA, and TC for that matter. The a/c was certified under the "extremely remote" clause, when that was proven false with the Broome incident the certification should have been pulled.

Why is the a/c still flying today when it clearly does not meet the certification requirements?

[SASless]

Outwest...... The extremely remote criteria does not say it will not happen....it also does not say the failure will not happen on two consecutive flights. Study your Laws of Probability a bit and you will see the complete fallacy of that kind of thought? Ever dealt two Ace's in a row...perhaps three...or even four?

Add in the wonderful art of Statistics (I used "art" rather than "science" on purpose) and you can see how easily the numbers can be manipulated to meet that definition of "extremely remote".

We all reasonably assume the rotor blades will stay on the head every time we fly a helicopter. Statistically they should, in reality they do, right up to the point they don't. I suggest "probability" says we have a fifty/fifty split each flight....either they stay on or they do not. Statistics warp that number to the good side....but even then do not guarnatee us a thing in reality.

The oil filter module was a miserably failed design....that is the truth.

Commonsense should have prevailed all down the line from SAC to the line engineers maintaining the aircraft and pointed out the flaws in that desgin. Especially after the previous failures. Sadly....that did not happen in such a manner as to prevent the tragedy from occurring. That does not mean the 92 is unsafe today if appropriate improvements/modifications have been done.

Brian......I can add a long lost of folks starting with Jerry Hardy that we have lost due to the fickleness of Fate! He was a true Gentleman! I recently stood at the site where we lost a full crew when a Chinook decided to come apart. I fully understand what Gann was talking about.

[Outwest]

SASless, I'm not a lawyer, but as I understand the certification process the a/c in question was required to have a 30 minute run dry capability "unless the probability of a total loss of oil was extremely remote"

Do I have that statement right?

If so, then it is no longer valid as it has been proven not once, but twice, that it no longer meets the "extremely remote" criteria.

Extremely Remote

* Qualitative: Not anticipated to occur to each item during its total life. May occur a few times in the life of an entire system or fleet.
* Quantitative: Probability of occurrence per operational hour is less than 1 \times 10^{-7} but greater than 1 \times 10^{-9}


As I've said before, I will give SAC and the FAA some slack in the initial certification, but after Broome they can no longer hide behind their own definition.

[squib66]

Industry Insider says:

Nobody outside of the operator's staff in Broome knew about it until after the landing.

While TSB say about that CHC incident:

Because a new stud and the proper tools were not immediately available, after consulting with Sikorsky's local field service representative, CHC carried out a temporary repair, installing a self-locking nut on the fractured stud. The self-locking feature of this nut did not fully engage the shortened length of the fractured stud so a hole was drilled in the nut to lockwire it for security. Although Sikorsky's engineering department was not specifically consulted, no technical objections to the temporary repair were presented by the Sikorsky field service representative.

and

It was the flight crew's understanding that the MGB would fail in a progressive manner rather than suddenly. Since the "less than 5 psi" condition coincided with the illumination of the red MGB OIL PRES warning message, the crew did not initially consider the low pressure to be a secondary indication of an impending gearbox failure. In addition, there were no other secondary indications detected and the MGB oil temperature remained below 80°C. This led the crew to respond as if they were in a "land as soon as possible" condition. The rapid drop in oil pressure was so different to their simulator training that they initially believed they had experienced a sensor or indicator problem. However, through collaboration, the pilots realized that the warning and oil pressure indication did not come from a single sensor, eliminating that possibility.

As the crew approached the only suitable landing area nearby, the rate-of-descent was increased and the pilots carried out a landing without further incident approximately seven minutes after the first warning. The captain indicated that if they had been flying over water, and there had been no other secondary indications, he would have continued flight toward land at an altitude of 200 feet agl and an airspeed of 80 knots.


http://resources3.news.com.au/images/2011/02/14/1226005/870407-chc-helicopters.jpg

So what did CHC actually do as a result of their investigation into the Broome incident?
Safety alert on repair authorisation?
Tighter maintenance control at Broome?
Change in maintenance programme?
A notice to crew about oil loss and what 'Land Immediately' means?
revised training?
Anything?

[zalt]

Squib - the silence is probably your answer. CHC have been very careful not to comment since the Cougar accident.

Here in Canada the familes are now pressing the Crown on why the S-92A was certified at all.

Families of Cougar Flight 491 crash victims want action from Ottawa

Families of the victims of a tragic helicopter crash off Newfoundland are putting pressure on Ottawa to act in the aftermath of a report into the accident.

http://www.thetelegram.com/media/photos/unis/2011/02/09/photo_1347984_resize_article.jpg

The request comes in a lawyer’s letter to Transport Minister Chuck Strahl on behalf of the families of the 15 passengers who died in the crash of Cougar Flight 491 in March 2009, as well as the sole survivor.

The Transportation Safety Board released its final report earlier this month, citing a number of factors in the crash of the Sikorsky S-92 including a severe loss of oil affecting the main gearbox.

The letter dated Feb. 18 calls on Strahl to investigate Transport Canada’s initial certification the S-92 helicopter.

“While the TSB report is extensive and detailed in many respects, it does not satisfactorily address critical questions pertaining to the manner in which the Sikorsky S-92 helicopter was initially certified by Transport Canada …” says the letter from the legal offices of Camp Fiorante Matthews.

The families also want Strahl to probe Transport Canada’s response to an incident involving the same type of chopper in Australia in July 2008. In that case, pilots of the helicopter arrived safely on land after losing oil pressure to the main gearbox.

Strahl has asked his department to respond to the TSB’s recommendations as soon as possible.

The families say they are looking for answers to questions about a number of issues in the interest of aviation safety and are not advancing a case for compensation.

To read the letter, and everyone here should, click here (http://ecostrategy.ca/wp-content/uploads/2011/02/letter.pdf)

The letter asks the key question. "Did Transport Canada succumb to pressure of the United States Federal Aviation Administration (FAA) or Sikorsky, or did they simply fail to recognize a serious safety/certification issue?"

Some people in Canda have noticed already that after the accident Sikorsky have actually been rewarded by gained business replacing the lost aircraft and providing and extra SAR aircraft. Is that really right considering the magnitude of their actions n late 2002?

The group, Victims of Cougar 491 is comprised of the following individuals (listed below) who are signators of the letter sent to Minister Strahl:

Brenda Anwyll, Janet Breen, Cecilia Corbett, Robert Decker, Wanda Drake, Melinda Duggan, Karen Eddy, Janet Escott, Susan March, Richard and Marjorie Maher, Heather Warren, Roxanne Mullowney, Marilyn Nash, Lori Chynn, and Sharon Pike

[212man]

Much as we all- I'm sure - sympathise with the authors of the letter, it would carry more weight if it did not contain factual errors!

The Super Puma does not have a 30 minute dry run capability


The S-92 is not the first Part 29 aircraft certified by the FAA that does not have a 30 minute run dry capability

I'm not being pedantic - I just think if you are going to start making claims of this gravity, you need to be 100% accurate in your assertions.

On another note (partially related) I see some progess appears likely with the FAA certification of the SAR AFCS:

Federal Register | Special Conditions: Sikorsky Aircraft Corporation Model S-92A Helicopter; Installation of a Search and Rescue (SAR) Automatic Flight Control System (AFCS) (http://www.federalregister.gov/articles/2010/12/13/2010-31188/special-conditions-sikorsky-aircraft-corporation-model-s-92a-helicopter-installation-of-a-search-and)

[Outwest]

Much as we all- I'm sure - sympathise with the authors of the letter, it would carry more weight if it did not contain factual errors!

* The Super Puma does not have a 30 minute dry run capability


Probably a lawyers misquote in referring to the 225 I suspect.

The S-92 is not the first Part 29 aircraft certified by the FAA that does not have a 30 minute run dry capability

Also not wanting to be pedantic, but I think it says "only" not "first".......

[212man]

Outwest, I suspect you are correct about the 225 but it's sloppy work for a lawyer! You are also correct that I erroneously used First rather than Only, but my point is still correct - it's not the only aircraft.

[Outwest]

I'm not that well versed on this whole Part 29 issue, can you tell me which a/c are certified to this standard?

OK, now I see what the lawyer is getting at with statement #9 of his letter.

He is referring back to #7 where he contends that because there were 2 cases of complete loss of lubrication in about 100,000 hrs, the "extremely remote" (once in 1 million) is no longer valid.

So, although I agree that it was sloppy to group the 225 as a "Super Puma" I think his statement in #9 can be argued as factual.

[Bladestrike]

CHC's response is well spelled out here,

Timeline - Cougar 491 | the fifth estate (http://www.cbc.ca/fifth/2009-2010/cougar_491/timeline.html)

About half way down the page, with links to various documents.

[Bladestrike]

And more recently here;

Investigator says problem flagged before fatal N.L. chopper crash - Business - The Telegram (http://www.thetelegram.com/Business/2011-02-07/article-2204069/Investigator-says-problem-flagged-before-fatal-N.L.-chopper-crash/1)

[squib66]

CHC's response is well spelled out here,

Timeline - Cougar 491 | the fifth estate (http://redirectingat.com/?id=42X487496&xs=1&url=http%3A%2F%2Fwww.cbc.ca%2Ffifth%2F2009-2010%2Fcougar_491%2Ftimeline.html&sref=http%3A%2F%2Fwww.pprune.org%2Frotorheads%2F365720-helicopter-crash-off-coast-newfoundland-18-aboard-48.html)

About half way down the page, with links to various documents.


Well spelled out? Really?

Of the two CHC documents:
1) Is an occurrence report that covers events up to landing
2) Is an email that mainly focuses on the poor service history of the S-92 gearbox

The other documents (and yopur second link) mostly relate to the lab testing. I was well aware of those investigative documents.

However there are no comments on any of the possible safety actions I would have expected would have been considered:

Safety alert on repair authorisation?
Tighter maintenance control at Broome?
Change in maintenance programme?
A notice to crew about oil loss and what 'Land Immediately' means?
revised training?

[Gemini Twin]

Wow, I've just read the following column in a Canadian Helicopter magazine which states:

Some aviators believe FAA part 29 requires the transmision to be able to run dry for 30 minutes. It does not. While I realize some will observe hindsight is 20/20, the only prudent action by the ill fated crew was essentially "written in stone". Had the pilots initiated an immediate and accelerated descent to landing on the water with a deployed emergency flotation system and prepared to abandon the helicopter if the sea state dictaed evacuation - everyone could have lived.

So it was the crews fault????

I suppose he means FAR part 29 and I'd like to remind him what is says in the FAR's

(1) Category A. Unless such failures are extremely remote, it must be shown by test that any failure which results in loss of lubricant in any normal use lubrication system will not prevent continued safe operation, although not necessarily without damage, at a torque and rotational speed prescribed by the applicant for continued flight, for at least 30 minutes after perception by the flightcrew of the lubrication system failure or loss of lubricant.

I would say that the similar problem in the southern hemisphere should be counted to show that failure was NOT extemely remote and a 30 minute test should have been demanded by FAA and Transport Canada.

The columns "author" provides accident reconstruction and "expert" opinions to law firms and the courts.

[squib66]

GT - Out of interest - Which magazine? Is it available online?

212man - While some slackness by the lawyer is regrettable, he seems to have got more right than Sikorsky's MGB designers.:sad:

[Gemini Twin]

Digital version on line at www.helicoptersmagazine.com (http://www.helicoptersmagazine.com) See page 38

[Lonewolf_50]

Gemini, did you read the TSB report?

The copilot more than once alerted the Pilot in Command that they were in a land immediately emergency/malfunction.

This in no way excuses whaterver design and maintenance errors may be surmised or determined from this mishap, nor the decisions post Broone that did or didn't get made and executed.

It seems to me that a cogent point being made is that "lost helicopter, BUT crew and pax survive" was a future foreclosed by the decision not to Land Immediately, or fly at a profile that allowed a quick flare and safe landing (see my remark a few pages up on the old Hawk 80/80 limp home speed with transmission problems, not sure what the S-92 similar profile would be). Lost helicopter, AND lost crew and pax(save one) is what sadly happened. Understanding the decision tree involved in the Captain's decision not to Land Immediately seems to me a crucial lesson learned, if one can be. Crews are faced with tough decisions all the time. How does one prepare crews to do so?

From the report, I feel comfortable taking the position that the crew's type training, as well as the training and flight manuals used, can be flagged as a "supervisory error" on the human side that contributed to the loss of life, if we accept that loss of the airframe was a mostly mechanical and maintenance issue, rather than a flying issue.

The reports provide a valid possiblity that the captain's choice not to ditch while it was still flying was informed by a training regime that didn't address the system he was flying with sufficient depth for critical items and critical actions.

That said, SASless' point remains well worth considering for anyone flying over very cold and rough water: would any of us ever want to ditch in high sea state, cold water, if we believed the bird could keep flying?

I seriously doubt I would ever have.

[squib66]

GT Thanks for that.
LW Especially if they were confident in the aircraft.


I've just looked back at a presentation given by the 'Director - S-92 Programs' in May 2003:

Page 2 starts by setting up requirements as a key part of the sales pitch


The S-92 is the 21st Century Aircraft

Complies with the Latest Standards and Regulations
Only the S-92 complies with all NEW FAA requirements of Part 29, amendment 45


Page 4 is ironic considering the parts that failed in Broome and St Johns


Only the S-92 is Flaw and Damage Tolerant
Critical Structures Absorb Flaws, Damage and Corrosion

From now on, helicopters will not be brought down by small corrosion pits, dents and damage due to field use!


Slide 42 rings very hollow now


Sikorsky Design Attention Will Continue Long After Production Delivery
Failure reporting and Corrective Action System (FRACAS)

Has been in effect since first flight on S-92
FRACAS System studies Items that affect safety, reliability, andcost
Relentless pursuit of problems will continue through Sikorsky World Wide Customer Service
Design engineers will continue to study and fix these problems
Operators, Sikorsky, Partners and Suppliers will work as a team to continue to improve the S-92 long into the future.Continuous Improvement After Delivery


Page 53 confusingly states


Only S-92 Is Designed and Tested to the Latest Standards for Safety and Robustness


To keep ahead of increasing safety standards, S-92 was designed to meet regulations not yet adapted {SIC} at the timeConsidering what was after the gearbox change the use of 'adapted' rather than 'adopted' looks like a Freudian slip.

Page 54 then has a photo of the Collier Trophy, awarded for 2002 to the S-92.

Other observations:
Amusingly on page 18, in discussing an accident, the identity of the type involved is deleted as 'not germane' (though their is a web address and date for the accident report), whereas on page 21 the S-92 is compared to another type, but the references are for S-92 and EH101. Is it churlish to point out that is was very germane to the VXX cometition?

Page 32 covers the SAR modes, not yet certified by FAA.

[Gemini Twin]

I've have read everything since the day it happened and I'm as shocked today as I was when I first noted that the S92 did not have to have a 30 min. loss of lube test prior to certification.

It's been my experience that the "extremely remote" alternate means of compliance is to be based on extensive in service histroy of a similar type. The S92 was a brand new type certified Cat A to FAR part 29!

Those guys should have had a better chance, it's not just 30 minutes run dry, but 30 minutes at a cruise power to be specified and approved by FAA prior to the test.

I've held my comments until know and only chipping in because of the column in Helicopters magazine today, which seem to point directly at the crew. "If the pilots had initiated an immediate.... everyone could have lived."

[zalt]

'adapted' rather than 'adopted'

Well spotted Squib
I'm not sure if I should laugth or cry.

Gemini Twin

What is odd is that column was written almost 2 years after the accident, but perhaps just a month before the final report - a dumb way to get caught out as a columnist.

Sweeping geralisation alert:
Whatever kind of helicopter you fly, from a Bell 47 to a Boeing CH-47, a loss of MGB transmission pressure dictates an immediate landing.

Not the best plan in a 225, 101, 139 etc!

The author also isn't familiar with how the S-92A floats are activated.

[Gemini Twin]

LW50. I get your point but....


zalt.
Most ignorant piece I've seen on the subject, but then again he's an expert who provides accident reconstruction and expert opinions to law firms and courts. That makes it all OK then.

[maxwelg2]

It's been my experience that the "extremely remote" alternate means of compliance is to be based on extensive in service histroy of a similar type. The S92 was a brand new type certified Cat A to FAR part 29!

GT, I'm assuming that SAC were using the Blackhawk history even though we all now know that the MRGB designs are quite different.

Wrt. the article written by Ken Armstrong perhaps he was alleviating to err on the side of caution i.e. don't rely on any run-dry time or glycol cooling or whatever the manufacturer tells you will work.

I myself as a PAX would rather take my chances with a ditching than an unknown MRGB real-time run-dry time with a full contingent of SLF, baggage, and whatever crappy weather the offshore throws at us.

Many lessons are to be learnt from 491 by all. Bashing a column based on data prior to the TSB report release isn't helping anybody. In fact IMHO the opposite is true as the column raises awareness again of the S92's MRGB limitations and the inherent issues in CRM, FSI, ops procedures and the RFM.

Safe flying

Max

[Outwest]

Just heard that there was another MGB foot crack discovered by a North Sea operator a few days ago.......

[Lonewolf_50]

Thanks for the reply, GT.

The amount of "lore" versus actual systems knowledge that accrues to an airframe, helicopter or fixed wing, grows and shrinks as facts fill in the blanks. It could very well have been some of that "lore" that led the pilot in command into thinking he had time that he didn't actually have. As that point has been beaten into the ground and covered again and again in this thread, I'll leave it at that.

[chw]

GT,

I agree with your comments you made regarding an article found in the back of a Helicopter magazine.:ok:


Traditionally helicopters are equipped with a MBG Oil pressure transmitter from which the MGB oil pressure indicator derives its signal, in addition to the MGB oil temp indicator there Is a low pressure switch which turns on a low pressure warning light.

In the S92 the pressure transmitter signal is also used to turn on a Caution message thru software in the DCU, I believe that it is possible the crew may have believed that when the caution message was changed to a warning message this to be coming from the same source (its is not). Further more The S 92 has over a 100 messages it would be hard to remember the source of each message. Also having been around a few oil leaks they often did result in a passenger to notify the pilot.

Engineering at SAC did think losing all oil to be "extremely remote" so now the pilot gets 5 minutes to make the dissison to try to safe all or land in the Atlantic.

The amount of harsh comments regarding the crew who paid the ultimate price due to bad engineering at SAC is shocking to me.

[Lonewolf_50]

The amount of harsh comments regarding the crew who paid the ultimate price due to bad engineering at SAC is shocking to me.

You appear to be reading something into the commentary on what drives a crew to make a particular decision, or just reading it with an emotional bias.

[blackdog7]

After reading the TSB report, I believe it speaks volumes for the benefits of the crashworthy systems required by the latest Part 27/29 regs.
No antemortem injuries to 7 of the 16 pax. Minor contusions to another, but all survived the impact at 2300'/min. vertical and 55-60 knots fwd speed. Two escaped the airframe, but only one made it to the surface.
Kudos to those who demand this level of safety in what they strap their (and their customers) butt to.

[squib66]

While you are factually correct:

it speaks volumes for the benefits of the crashworthy systems...

No antemortem injuries to 7 of the 16 pax. Minor contusions to another, but all survived the impact at 2300'/min.

But 14 of the 16 pax failed to escape from the aircraft
15 of the 16 pax failed to survive.

Both crewwere badly injured by contact with the structure in the cockpit and unable to escape. TSB have already recommended helmets for pilots.

I see Cougar now partly fund helemts for their crew. I wonder if their SAR crews have to pay towards their own safety equipment.

A case of a crashworthiness success but 94% of the occupants perished?

[SASless]

Both of you are correct.....let's see if you can agree on why how to change that survival rate! What caused the lack of successful escape from the aircraft? Cold Water....being knocked senseless by the impact....lack of HEEDS air....bad exits....survival suits failed/delayed exit.....what was it?

[blackdog7]

Better Immersion Suits, EUBA, more frequent HUET.....all would have helped. unfortunately, all 15 died from drowning.
Point I was trying to make is that crashworthy features do work but far too many pilots ignore the advances they have brought to this industry.
Had that accident happened onshore, the results would have been significantly different.

[JimL]

Leaving aside the reason for the crash/ditching (which has been endlessly discussed over the last two years) there are three main elements which have to be considered when a helicopter comes into contact with the water:


if the helicopter is performing other than a controlled manoeuvre; crashworthiness (seat stroking, maintenance of the integrity of the cabin, retention of the seats to their fixings, etc).


the ability of the occupant to escape from the cabin.


the ability to survive in open water after escaping from the cabin.

The objectives of 1. are facilitated by the certification standard that applies at the time of the granting of the type certificate (and applies equally to a crash on land as well as on water).

The objective of 2. is facilitated by a number of elements, most of which are satisfied when "certification with ditching provisions is requested". These provision include structural integrity, behaviour of the helicopter in a water landing and 'under reasonably probably water conditions (that) the flotation time and trim...will allow the occupants to leave the rotorcraft and enter the life rafts...'. Ditching approval is usually only required when specified by the Operational Regulations (as it is in ICAO Annex 6 Chapter 2.2.12 and JAR-OPS 3.843).

Point 3. is covered by other provisions (once again, in the Operational Regulations) which specify the carriage of life-rafts (and provisions to ensure that they are available and can be launched) the wearing of survival suits, constant wear life vests, the provision of pop-out windows and measures to ensure that the life-rafts are not punctured immediately after their launching. Operational rules also contain elements to ensure that the location of the helicopter is known during flight and also after ditching.

Some important issues spring to mind (discussed in the accident report): in AC 29-2C is contained the following clarifying text:
The FAA/AUTHORITY has determined that a sea state 4 is representative of reasonably probable water conditions to be encountered. Therefore, demonstration of compliance with the ditching requirements for at least sea state 4* water conditions is considered to satisfy the reasonably probable requirement.
* From AC 29-2C it is established that Sea State 4 (wind 17kts - 21kts and signification wave height of 4 to 8 ft).

As you will have seen from the statistics in the report, the Sea State in the Canadian East Coast, the North Sea (and most other open bodies of water North of 45N and South of 45S) is above SS4 for a significant proportion of the time in the winter. Almost a decade ago, there was an attempt to have the AC amended to take account of that fact - it was not successful. In the meantime, the oil companies, deciding that they could not rely upon the regulator to make changes to the guidance, through discussions with the manufacturers and by contractual arrangements, decided to press ahead in an attempt to meet Sea State 6.

Helicopters can survive upright in quite high sea states - if the waves are regular. As we all know, it is the breaking of the wave that dictates when capsize occurs. For that reason, nothing modelled/established in regular waves can be guaranteed. Because we know that it is likely that the helicopter - with its high centre of gravity - will capsize, the principle of 'side floating' was investigated. (Side floating is intended to ensure that after a capsize, one side of the cabin will remain above water.) It is not easy to retrofit but it can be done.

As has been seen from this accident (and as was established in the RHOSS Report in 1995), most passengers will survive an initial impact but will subsequently drown in the cabin. The reasons why are complex. 'Brooks' established in his Canadian trials that breath-hold capacity was insufficient to permit evacuation of the passengers through the emergency exits, following a capsize. We know that cold shock can reduce the breath-hold capacity to less than 10 seconds - even for very experienced personnel. It is for that reason that pop-out windows are provided with the proviso that every passenger should be only one removed from the emergency exit.

Even with this it may also be necessary to increase the size of the pop-out windows and provide a method of increasing the breath-hold time to ensure it exceeds the escape time - by some margin.

Automatic float inflation and externally-launched life-rafts have been systematically fitted in the offshore fleet. It is real progress. However, during a crash, any portions of the emergency kit that is in the impact zone is likely to be damaged and cease to function. We have seen in modelling tests that critical elements of the emergency equipment can be lifted away from the likely impact zone - attention must be paid when considering such reasonably probable events.

Just some points with an impact upon offshore survivability.

Jim

[Lonewolf_50]

Jim, very well stated on the issue of combining both the upset of capsized helicopter and the shock hazard of very cold water. I was skeptical of HEEDS when it first came out, in the USN, over 20 years ago, but a couple of my friends were in mishaps with HEEDS available and made me into a believer. It gives you those blessed extra seconds of not having to deal with "where the hell is my air?" while allowing one to deal with with "get out hand over hand before this thing takes me to the bottom!"

[squib66]

Automatic float inflation and externally-launched life-rafts have been systematically fitted in the offshore fleet. It is real progress. However, during a crash, any portions of the emergency kit that is in the impact zone is likely to be damaged and cease to function. We have seen in modelling tests that critical elements of the emergency equipment can be lifted away from the likely impact zone - attention must be paid when considering such reasonably probable events.



Like the S-92 rafts in the front of the sponsons that themselves are designed to seperate in the event of a crash.:ugh:

[Variable Load]

Like the S-92 rafts in the front of the sponsons that themselves are designed to seperate in the event of a crash.

My understanding is that the part that contains the liferaft is not designed to detach, just the fuel tank.
The picture of the post crash Cougar machine in the hangar shows this.
Good try - but wrong. More squib66 bs :mad:

[[email protected]]

Jim We know that cold shock can reduce the breath-hold capacity to less than 10 seconds - even for very experienced personnel. In a recent conversation with an acknowledged expert in this field I gleaned 2 key pieces of information -

1. In cold water you have at most 5 seconds and probably less because of the body's reaction to immersion ie gasping/hyperventilation - it is not really a 'breath-hold'.

2. In order to escape promptly, you are far better off being on the air system before immersion rather than having to panic to find it afterwards.

Interestingly, it is possible to train yourself to improve breath holding time following cold water immersion but it involves (guess what) immersing yourself in cold water regularly - probably not that practical for oil workers I suspect.

[squib66]

The TSB estimated that (see report section 1.15.1):
CHI91 impacted with the water with an estimated force in the magnitude of 20g to 25g.

However because the structure absorbed some of that acceleration:
Except for the four passenger seats that bottomed out, the occupants were generally subjected to inertia load factors between at least 5.3g and 8.6gin the direction of the vertical seat axis. In addition, the helicopter struck the surface with a forward velocity of approximately 55 to 60 knots which would have introduced a horizontal force on the occupants of approximately 5g to 8g

The effect of these lower g levels are clearly evidenced by the suprisingly low level of impact injury amongst the passengers (though not the crew).

From the TSB report (1.3) it is clear both sponsons broke off (which is what Sikorsky's marketing said they would do):

Some floating debris was recovered by surface vessels including the left sponson and fuel bladder, rear cargo door, two life rafts, other lightweight buoyant materials, and some personal effects.

The right sponson and fuel bladder were not recovered.

On the rafts (from 1.12.7 - underling added):

The helicopter was equipped with two life rafts, one stowed in the forward portion of each sponson. Both life rafts were recovered fully inflated and floating near the impact site. The rafts likely inflated when the lanyards, attached to the rafts and used to manually inflate them, were pulled as the storage compartment's cover separated from the sponsons at the time of the impact.


The sole survivor in his testimony to the public inquiry did see the rafts blowing away in the wind (the raft sea anchors are manually deployed once someone is on board the raft - an area for possible design improvement).

The LH sponson was postioned alongside the fuselage:
http://www.tsb.gc.ca/eng/rapports-reports/aviation/2009/a09a0016/images/a09a0016_photo_5.jpg

It is clear that the sponson is not attached to the LH main landing gear support structure which is still attached to the fuselage.

Critically to this dicussion the LH liferaft bay remains at the front of the sponnson and attached to the fueslage.

Therefore I believe my earlier statment is correct Vertical Load based on facts.

I also note that in 1.12.7 it is clear that Jim L's point on the protection of ctitical systems was not properly addressed in the case of the S-92 to the satisfaction of the TSB:

The immersion switches in the wheel wells were disabled when the sponsons were torn away by the impact.

There is very little point being able to survive an impact if you drown rapidly because essential safety systems have been disabled.

[zalt]

A very good point JimL/Squib66

At Heli-Expo at least one company is showing the robustness of the MGBs they make after an oil loss

Timken Hosts Famed U.S. Army Pilot at Heli-Expo -- CANTON, Ohio, March 3, 2011 /PRNewswire/ -- (http://www.prnewswire.com/news-releases/timken-hosts-famed-us-army-pilot-at-heli-expo-117364328.html)

Apache's Timken-built Transmission Survived Extreme Dry-Run Conditions In Afghanistan

CANTON, Ohio, March 3, 2011 /PRNewswire/ --

The Timken Company (NYSE: TKR) hosts former U.S. Army Chief Warrant Officer 4, Jim Hardy, at its 2011 Heli-Expo exhibit #1306, March 6-7, 2011 in Orlando, Fla. Timken invites attendees and exhibitors at the show to meet Hardy and hear his story first-hand.

Hardy piloted his Boeing Apache AH-64A 50 miles back to base after it suffered complete oil loss as a result of an enemy air strike during operations in Eastern Afghanistan. The Apache's Timken-built transmission helped ensure that Hardy and his team were able to fly back to base, even under these extreme operating conditions.

During a military security detail, a rocket-propelled grenade attack left several Apache AH-64A rotorcraft severely impaired. The worst damage was to an Apache that had lost its weapon controls and was hemorrhaging oil from a battering of bullets and grenades.

As one of the most experienced pilots on the mission, Hardy directed his fellow officer in the more severely wounded Apache to follow him. Forced to make an emergency landing under open fire, Hardy moved to quickly inspect the more damaged Apache and found its transmission oil reservoir was completely drained. He knew that abandoning the helicopter would require a dangerous recovery mission; also, he considered the greater risk that the Apache could end up in enemy hands.

Finding neither of these scenarios acceptable, the team fed six quarts of spare oil into the Apache's constantly-depleting reservoir, and Hardy took command of the damaged aircraft in a swap with his fellow officer. Then, testing his own nerve and the performance of the Apache's Timken-built transmission, Hardy piloted the Apache nearly 50 miles back to base.

The successful 26-minute journey ensured the safety of everyone on the security detail, for which Hardy received the U.S. Army's Distinguished Flying Cross.

"Hardy's story is an awe-inspiring reminder that the technology Timken delivers often is involved in risky operations and sometimes heroic events, in civilian and military service alike," says Erik Paulhardt, Timken vice president - aerospace and defense. "We place tremendous emphasis on the quality of our products, which serve a mission-critical role. Whether our technology is involved in powering flight to fight wild fires or to carry out rescues, we never forget that every day, crucial operations rely on Timken's promise of performance, backed by our industry leading expertise in power transmission."

[ironchefflay]

Therefore I believe my earlier statment is correct Vertical Load based on factsI'm afraid not. the sponson is made up of three parts. the forward sponson, where the raft is, fuel tank section in the middle and the rear sponson where the main undercarriage is.

The middle section has fusable mounts like an engine pylon on fixed wing jet, allowing it to break away fron the front and rear parts taking the fuel away from the occupants in a ditching and hopfully not rupture in a crash landing on land. if you look at other clearer pics of the sponson taken fron the other side you will see the forward (and rear) sponson still attached to the fuselage. with the raft container empty.

[212man]

Squib,
as Variable Load flies the S-92 (and has done so for 5 years) and Ironcheflay maintains them, I think it's fair to say that they know what they are talking about, so I'd back down on that one........

[zalt]

IC - well spotted. However if you compare the paint scheme of the structure behind it with a photograph of the Cougar scheme it appears that the raft structure did seperate from the aicraft because they don't match.

The rafts still seperated from the aircraft and blew a way from survivors and the float system was still disrupted and did not activate..

[zalt]

212man - just seen your post. So you don't think much of JimL's comments then? Do you know his backround by any chance;). Pity - I though there were some forward thinking ideas from Jim there.

Unions are still pretty unimpressed with the S-92 too:

The union representing some Newfoundland and Labrador offshore workers is supporting a call on the federal government to investigate the certification of the type of helicopter that killed 17 people after crashing off the coast of Newfoundland in 2009.

The families of Cougar crash victims and the sole survivor, Robert Decker, want Transport Canada to find out why the chopper – a Sikorsky S–92a – was permitted to fly in Canada when it was shown in 2002 that it couldn't run for 30 minutes without oil.

Communications, Energy and Paperworkers Union representative Kevin Kelly, who speaks for some workers on two offshore oil platforms east of St. John's, said the union supports the families' request.

Kelly said the S–92a dry-run time isn't the only problem that needs to be addressed.

"We also had cracked footing mounts … so over time, if they can't resolve these issues they'll look to another chopper, right?," he said.

Last May and earlier in January 2010, a Cougar Helicopters Sikorsky chopper was been grounded in St. John's because of a crack near the gearbox.

U.S.-based manufacturer Sikorsky said the crack is in a footing that attaches the main rotor's gearbox to the body of the aircraft. In a separate incident, another Cougar S–92a helicopter was grounded in Halifax in November 2009, after a hairline crack was found.

Last week, the families and Decker wrote Federal Transportation Minster Chuck Strahl to investigate certification of that model of helicopter by the Federal Aviation Administration in the U.S.

The Transportation Safety Board of Canada (TSB) released its final report on the crash Feb. 9.

Relatives of the passengers killed and Decker have had time to review the report and believe fundamental issues related to the S-92a's certification have not been addressed.

"Did Transport Canada succumb to pressure from the United States Federal Aviation Administration (FAA) or Sikorsky, or did they simply fail to recognize a serious safety/certification issue?" said the letter to Strahl.

Cougar flight 491 crashed 11 minutes after its pilots saw an indicator suggesting the helicopter's main gearbox was losing oil pressure.

The letter said it should have been "obvious" to Sikorsky and the FAA in 2002 that the S–92a did not have the 30-minute run-dry time it was advertised as having.

"On Aug. 6, 2002, Sikorsky carried out its initial certification test to demonstrate to the FAA that the MGB could run dry … the main gearbox suffered a catastrophic failure approximately 11 minutes into test," the letter said.

"At that point, it was obvious to Sikorsky and the FAA that the helicopter was incapable of meeting the run dry requirements for certification."

Minister supports recommendations

"We support the intent of the TSB recommendations to improve helicopter safety," Strahl said last week in a response emailed to the CBC.

"We intend to respond within the required 90 days. However, I have instructed my department to respond to the recommendations as soon as possible so that appropriate action can be taken to improve the safety and security of Canadian aviation."

The Minister also said he has directed his department to work with the U.S. Federal Aviation Administration "to ensure we have a closely aligned and appropriate system in place for assessing the airworthiness of aircrafts and parts."


N.L. union joins call to investigate chopper - Nfld. & Labrador - CBC News (http://www.cbc.ca/news/canada/newfoundland-labrador/story/2011/02/28/nl-union-chooper-228.html)

I'd be really interested in hearing from anyone in Shell what their views are on this.

After all, Shell's 7/7=1 strategy is heavily underpinned by a move to aircraft that comply with the lastest certification standards.

Its ironic that the S-92s first fatal accident has been so closely linked to a failuer to meet a certification requirement that other types have achieved (or exceeded) and a failure that earlier generation types could actually better cope with.

The suggestion that pressure during certification to waive a safety rule resulted in a fatally flawed design being released in to service is clearly one that is exercising a lot of concern here in Canada.

[212man]

Zalt,
I've no idea what you are talking about?? I was referring to the exchange between Squib and Variable Load regarding the sponson design. The fact that the raft containing structure may well have detached, is not related to the sponsoon design with respect to the fuel tank detachability - it simply reflects the strength of the impact. Like many topics in this thread, it's a red herring as even if they had remained attached they would not have been deployable in this case, as by all accounts it appears the aircraft started sinking quite quickly.

Another red herring is the sea state - SS4 is not one that the average offshore pilot in NE Canada or the North Sea would consider rough. It is actually at the lower end of the range of typical sea states seen day to day, and I do not accept it would be seen as a deterrent. I do accept that the sea temperature might be, but if a controlled ditching is carried out it shouldn't be a deterrent in its own right.

That's not to say that discussion of sea state's is not a valid topic and discussion point. Adverse Weather Policies came into effect in the North Sea following the G-TIGH accident in March 1992, where significant difficulties were encountered in rescuing survivors. It was night, 55+ kt winds and 10m waves! Oh, and snowing. So I agree that sea state limits probably do need applying for routine operations.

One point the TSB note is the possible conditioning of the crew by their simulator training. I think this is an important point and I have personally raised this subject in the past. In fact, at the time of this accident it was not possible to simulate total oil loss or a zero pressure event and I'm surprised that this wasn't mentioned. Even with this simulation added, there are still aural and vibration cues that develop which are precisely the kind of additional symptoms the commander was looking for and so the potential for conditioning still remains.

JimL? Yes, I'm well aware of his background thanks very much for asking. He's also one of my Facebok friends, Skype contacts and in my phone contacts.....:ok:

[ironchefflay]

However if you compare the paint scheme of the structure behind it with a photograph of the Cougar scheme it appears that the raft structure did seperate from the aicraft because they don't match.

I cant agree with that. not based on what is visible in that photo. not even zoomed in can you see any significant detail. there is also the fact that a lot of post impact damage can occur on the way to the sea bed and from powerful underwater currents so i could not endorse your statement from the evidence you provide. if you have seen it it person, then maybe!

however, the rafts stayed on the surface so the system worked. if they remained tethered to the aircraft they would have been dragged under so you cant blame sikorsky because they floated away! a sea anchor wouldnt stop that either unless its made of iron and goes to the sea floor, and thats unlikely!

[riff_raff]

At Heli-Expo at least one company is showing the robustness of the MGBs they make after an oil losszalt,

Thanks for the link. That particular AH-64 MRGB lube system situation was a bit different than what happened with the Cougar S-92 MRGB, but it does provide a perfect example of how a gearbox can achieve a loss-of-lube operational capability.

Most MRGB's have high lube circuit flow rates because they use lube oil for cooling. To keep weight down, the MRGB lube system oil volume is kept to a minimum, and thus the turn-over rates tend to be quite high. I don't know the specifics behind the S-92 MRGB, but if I had to guess, I'd say its lube oil circuit turn-over rate is probably around 15 or 20 seconds at most. And if there's a serious leak in an external hose, filter housing, heat exchanger, etc. that contains 100% of the system flow rate, all of the MRGB oil volume can be discharged very quickly.

While the noted AH-64 MRGB has a qualified loss-of-lube capability, what really helped it survive was that the oil leak situation was probably not completely catastrophic in nature, and possibly some small amount of oil remained circulating. Even a fine mist of oil sprayed on the gears and bearings is enough to reduce friction and limit thermal failure of these parts.

Supplementary total loss back-up lube circuits are a very effective way to provide an MRGB loss-of-lube operational capability. But such systems tend to be complex, expensive, and add weight, so they are not widely used. If there is a push to qualify MRGB's with loss-of-lube capabilities beyond 30 minutes, they may become more common.

riff_raff

[Variable Load]

Maybe we can meet in Vancouver and discuss these issues?

Well I'll be there for "discussion" - preferably over a beer :ok:

[zalt]

Aviation.ca - Your Number One Source for Canadian Aviation News, Jobs and Information! - Grim Anniversary Remembered (http://www.aviation.ca/content/view/9660/117/)

Grim Anniversary Remembered
Two years ago today, the crash of Cougar Flight 491 changed the lives of many in Newfoundland and Labrador. A memorial service will be held Saturday evening at the Anglican Cathedral in St. John's to remember the 17 people who died in the crash. Cougar Flight 491 crashed into the Atlantic on March 12, 2009. One man, Robert Decker, survived the accident. The public service Saturday is being organized by Ezra Chaplaincy, and will take place at 6:30 p.m.

The crash prompted an inquiry in this province into offshore helicopter safety. The Transportation Safety Board issued its report on the crash last month, citing sixteen factors which contributed to the accident.

NDP leader Lorraine Michael released a statement marking the second anniversary. Michael says that March 12th is a day that will be forever etched in the hearts and minds of all Newfoundlanders and Labradorians, adding that her thoughts and prayers are with the families of the victims, and with the sole survivor, Robert Decker. Much as been accomplished in the last two years, Michael notes, including the release of the Offshore Helicopter Safety Inquiry recommendations, and she thanks author Justice Robert Wells for his dedication. Michael also remarks that, as we remember those who lost their lives, we should be directing our attention towards a safer oil industry. She adds that we owe it to the crash victims and their families to make the offshore as safe as possible. Positive changes will continue to happen as a result of Cougar Flight 491, Michael concludes, and she hopes no family will ever be forced to face this type of tragedy again.


Sikorsky have the chance to testify.

N.L. chopper crash inquiry enters Phase 2 - Nfld. & Labrador - CBC News (http://www.cbc.ca/news/canada/newfoundland-labrador/story/2011/03/11/nl-crash-phase-two-311.html)

N.L. chopper crash inquiry enters Phase 2

An investigation into the crash of Cougar Flight 491 is heading into its second phase.

The public inquiry, headed by Commissioner Robert Wells, was launched following the crash, which killed 17 people off the coast of Newfoundland in March 2009. The helicopter was travelling to an offshore oil platform with 18 people aboard when the accident happened. There was only one survivor, Robert Decker.

In Phase II, Wells is looking for updates on safety initiatives and suggestions on how the commission should approach the findings of the Transportation Safety Board.

He has already met with participants from Phase I who requested standing in Phase II. The general public can also make written submissions.

Interested groups or individuals have until April 15th to submit.



RIP

[squib66]

The MGB certification is not going to go away:

Report brings new attention to 2009 crash of Pa. firm's copter | Philadelphia Inquirer | 03/20/2011 (http://www.philly.com/philly/business/118313494.html?viewAll=y)


Posted on Sun, Mar. 20, 2011

Report brings new attention to 2009 crash of Pa. firm's copter
By Linda Loyd
Inquirer Staff Writer

A transport helicopter built by Coatesville-based Sikorsky Global Helicopters was ferrying workers to an oil rig 200 miles off the coast of Newfoundland in March 2009 when a complete loss of oil from its gearbox sent the chopper plunging helplessly into the North Atlantic.
Only one of the 18 people aboard the Sikorsky S-92 survived. All were citizens of Canada, and the incident got little attention here.

However, a report issued last month on the crash and renewed calls by families of the victims for tougher safety standards on large passenger helicopters - and on the multimillion-dollar S-92 in particular - have focused new attention on the two-year-old tragedy.

The U.S. Federal Aviation Administration says the S-92 aircraft that is used for oil-rig commutes, rescue work, and VIP shuttles around the world met its safety requirements.

In a 176-page accident report released Feb. 9, Canada's Transportation Safety Board (TSB) called on the FAA and regulators in Canada and Europe to require all so-called Category A passenger helicopters to be able to stay in the air at least 30 minutes after a total loss of lubrication oil in the transmission's main gearbox.

The helicopter that crashed with 16 passengers and two crew members aboard was 28 minutes into a 90-minute flight from St. John's, Newfoundland, to the massive Hibernia oil platform when an oil-pressure warning light flashed on.

The crew did not know that two of three titanium studs that held the oil filter to the main gearbox had broken, and the brawny helicopter was out of oil - with just 11 minutes to safely land. It was on its way back to St. John's when it fell out of the sky.

The S-92 - there are 132 in the world - is made by Sikorsky Global Helicopters, formerly Keystone Helicopter Corp., in Coatesville. The S-92 that crashed was manufactured in 2006 and leased to Cougar Helicopters Inc., of Canada. Some assembly work was done at Sikorsky's plant in Stratford, Conn., and some in Coatesville, where all Sikorsky commercial helicopters are now built.

After the fatal accident, upgrades were made to the S-92, including replacing titanium studs with steel and redesigning the mounting that bolts the transmission to the helicopter, Sikorsky spokesman Paul Jackson said.
"In the last 12 months, we've made 21 major upgrades to that helicopter. We are working on additional gearbox improvements," Jackson said.
"Sikorsky and, from what we are told, our customers stand 100 percent behind the S-92 helicopter. It's solid. It's safe. It's proven."

While a repeat of the stud failure that caused the 2009 crash is highly unlikely, "that gearbox still has only 11 minutes" after a loss of its oil, said Wendy Tadros, chairwoman of Canada's TSB.

Every helicopter that competes with the S-92 has met the certification requirement of draining the main gearbox oil and continuing operation for 30 minutes - a term referred to as "run dry," the TSB report said.

"Every Sikorsky helicopter, other than the S-92, has a 30-minute run-dry capacity," said Martin Brigham, a Philadelphia lawyer representing the Canadian families. The helicopters include the UH-60, Sikorsky's Black Hawk military helicopter; the Sikorsky S-61 and the VH-3, which is the presidential helicopter; and the Sikorsky S-76.

"Every other large commercial helicopter in the world has a 30-minute run-dry capacity, including the Eurocopter Puma series (AS332 and EC225) that carry 19 passengers and are used for offshore oil rigs," Brigham said, "as well as the Eurocopter AS365 and EC155, and Agusta Westland AW139."

A smaller helicopter, the McDonnell Douglas MD-900 Explorer, also has that run-dry capacity.

The TSB and the victims' families want the FAA to do away with what they consider a loophole in the current rule.

A 1988 FAA rule requires that a helicopter be capable of continued flight for at least 30 minutes after gearbox oil loss, but also includes a provision exempting a manufacturer if such a failure was considered "extremely remote."

It was on that basis that the S-92 was certified in 2004 by the FAA as airworthy, even though it had failed the initial certification test.
During a demonstration with the FAA in 2002, the S-92 gearbox failed about 11 minutes into the test. Rather than redesign the gearbox, Sikorsky asserted - and the FAA accepted - that the S-92 should be certified because the risk of a complete oil loss in the main gearbox was "extremely remote."

"We are asking the FAA to remove the 'extremely remote' phrase and say flat out this helicopter, and every helicopter in this category, has to meet the 30-minute run-dry test," Tadros said.

The FAA and its Canadian equivalent, Transport Canada, are expected to respond by May 15, within 90 days of receiving the recommendations. "I can't answer how we are going to respond," FAA spokesman Les Dorr said. "We certificated the helicopter. We believe the way that Sikorsky showed compliance with that 30-minute run-dry provision satisfied the requirement."

The families of the Canadian flight victims and the one survivor sued Sikorsky and its parent, United Technologies Corp., in Philadelphia Common Pleas Court.

The case settled quickly, and the families received undisclosed financial compensation. A cadre of lawyers in Philadelphia, New York, and Canada were involved, led by Marty Brigham of Raynes McCarty, of Philadelphia, for the families, and James Stroud of Rawle & Henderson L.L.P., also here, for Sikorsky.

Before the crash, Sikorsky was investigating a July 2008 incident in Australia that also involved broken titanium studs on an S-92 helicopter, which made a forced landing after a sudden loss of oil pressure.

After Australia, Sikorsky put in place new maintenance procedures for the studs, but they did not immediately require replacement.

On Jan. 28, 2009 - six weeks before the March 12 crash off Newfoundland - Sikorsky issued an Alert Service Bulletin requiring that all titanium studs be replaced with steel, but it gave operators 1,250 flight hours, or up to a year, to do it.

The FAA immediately after the accident ordered the S-92 fleet grounded until all titanium studs were replaced with steel.

Although the litigation is over, the families still have questions. They wrote Canada's minister of transport last month, demanding an investigation of the original S-92 certification and asking why Transport Canada did not take action soon after the Australia incident.

"It should have been obvious to Transport Canada that the potential for complete loss of oil from the S-92 was anything but 'extremely remote' and the assumption on which the aircraft was certified was invalid," the families wrote.

Jobs in the offshore oil and gas industry pay well, and nearly everyone on the Canadian coast knows someone who works on an offshore rig.
Passengers on the fatal flight included Allison Maher, 26, the youngest, who worked in housekeeping. The oldest was Peter Breen, 55, a father of four who was a steward in catering. Others were engineers, scaffolding and rigging workers, a cook, a hydraulic technician, a medic and registered nurse, and a shipboard director of kitchen and laundry.

In the North Sea, the United Kingdom operates 215 offshore oil and gas installations, employing 30,000 workers. Canada has seven offshore platforms, employing 2,000. Worldwide, there are 2,800 offshore rigs.

"We want the FAA to look at today's operating environment, and the technology that's available, because these types of helicopters are operating further afield," Tadros said. "The question is: Are the certification standards that were set in the late 1980s adequate for today's operations?"

Helicopter Safety

After the March 2009 fatal crash of a Sikorsky transport helicopter 35 nautical miles from Newfoundland in the North Atlantic, safety investigators in Canada have called for four reforms:

Require all large transport helicopters worldwide to be able to operate at least 30 minutes after a loss of main gearbox lubrication - a measure taken from the military, where if enemy fire punctures the oil supply, the aircraft has 30 minutes to get to safer territory.

Consider extending the "run dry" rule well beyond 30 minutes, since aircraft are flying farther offshore and technology is available.

Forbid helicopters from operating over water in Canada when rough seas exceed the capability of the chopper's emergency flotation system.

Require supplemental breathing equipment in all transport helicopters in Canada, in the event the helicopter capsizes and passengers are in the water.

SOURCE: Canada's Transportation Safety Board
Contact staff writer Linda Loyd at 215-854-2831 or [email protected] (http://www.philly.com/philly/business/mailto:[email protected]).



Note the error on the AS332 is repeated: The S-92A MGB only managed to be as good as the L and ran 17 mins less than the L2 after a true oil loss.

[zalt]

The MGB certification is not going to go away:


Correct.

It remains a political issue here.


Certification of S-92 needs change: widow
Published: March 23, 2011 2:57 p.m.
Last modified: March 23, 2011 3:02 p.m.

OTTAWA - The widow of one of 17 people killed in a helicopter crash off Newfoundland two years ago is questioning why Transport Canada certified the aircraft when it "failed an important test."

Lori Chynn is pressing the federal government to review its certification standards and explain why it gave the Sikorsky S-92 an airworthiness certificate when it couldn't meet a certain requirement.

In a statement Wednesday, Chynn and two federal NDP MPs said it was known years before the Newfoundland crash that the helicopter couldn't fly for 30 minutes without oil.

In a letter to Transport Minister Chuck Strahl, she said she wanted to know why "this type of helicopter (was) given an airworthiness certificate when it failed an important test."

Chynn said more needs to be done to protect workers travelling long distances to get to offshore oil platforms, like the one her husband worked on as a nurse.

"I believe that we must learn from this tragedy and do what is necessary to ensure the safety of those who continue to work offshore," she said at a news conference in Ottawa.

"Safety must come before profit."

Chynn's husband, John Pelley, died along with 16 others when the S-92 they were in went down in waters off St. John's as it headed to a rig. Only one person survived.

A Canadian investigation into the crash showed that some of the titanium gearbox studs broke, causing a critical loss of oil.

Jack Harris, NDP transport critic, said Wednesday that aviation standards require a helicopter to fly for a minimum of a half-hour without any oil in the main gearbox.

But he said a certification test in August 2002 showed the Sikorsky couldn't meet that 30-minute standard, failing after 11 minutes of dry operation.

Still, Harris said Transport Canada certified the S-92 as safe to fly, with the caveat that a complete loss of lubricant was extremely remote.

He said the government also didn't address the certification issue when the same model of helicopter crashed in Australia in 2008 due to a loss of lubricant in the gearbox.

Harris said Canadian officials examined that gearbox and found "the Sikorsky S-92 did not meet the 30-minute dry run capability and it had a problem about the loss of oil.

"Yet no changes were made to the certification of the S-92."

Harris said after the Newfoundland crash, the studs were ordered to be replaced with steel ones but the helicopter still lacks the 30-minute dry run capability.

Transport Canada was not available for comment.




Metro - Certification of S-92 needs change: widow (http://www.metronews.ca/vancouver/world/article/811243--certification-of-s-92-needs-change-widow)

[squib66]

It looks like an attempt by Sikorsky to stop a court hearing in Canada has failed:


The helicopter in question was originally purchased by CHC Helicopter Corporation as part of the sale of 12 such rotorcraft. That sales agreement provided that the law of Connecticut governed. The helicopter was then sold by CHC to Lloyds TSB General Leasing (No 20) Limited, which, together with certain Lloyd's underwriters, is its beneficial owner.
On the sale of the aircraft to Lloyds 20, a novation agreement was executed wherein the obligations assumed by CHC were transferred to Lloyds 20, which became bound by the original contract of sale, with the exception that Sikorsky now accepted that the law of England and Wales applied and exclusive jurisdiction for the resolution of disputes was with the English courts.

In March 2007 Cougar leased the helicopter from Lloyds 20. Under the terms of that lease, Lloyds 20 was to be the loss payee under the insurance that was to be procured for the helicopter.

Two separate legal proceedings ensued as a result of the crash.

The first, commenced in June 2010, involved Sikorsky commencing an action against Cougar and Lloyds 20, seeking a declaratory order that any claim related to the crash would be adjudicated in Connecticut, in accordance with Connecticut law, and further seeking an order prohibiting Cougar, Lloyds 20 or the Lloyd's underwriters from commencing litigation in any other jurisdiction. This application was opposed.

Eight days after the Connecticut application was filed, Sikorsky was served with a Newfoundland claim commenced by Cougar, Lloyds 20 and the Lloyd's underwriters (as well as others). As an aside, one of the other parties was Helicopter Support Inc (HIS). After commencement of this proceeding, the plaintiffs served a notice of discontinuance with respect to the HSI claim and the proposed issuance of such notice was unsuccessfully challenged by Sikorsky.

The overall claim was based on alleged torts that had occurred in Newfoundland - more specifically, negligent design and manufacture of the main gearbox on the helicopter, negligent/wilful/fraudulent misrepresentation and failure to warn. No breach of contract was identified in the claim and there is no contract between Cougar and Sikorsky (although Lloyds and Sikorsky are contractually linked, as discussed above).

On receiving the claim in the Newfoundland action, Sikorsky sought to prevent Cougar and Lloyds from proceeding with the Newfoundland claim for a number of reasons.

In short, the Newfoundland court had to decide whether:

in contesting the discontinuance against HSI, Sikorsky had attorned to the jurisdiction of the Newfoundland courts;
it was appropriate to order a temporary stay of the Newfoundland action while the Connecticut application was determined (and while a case involving similar issues was determined by the Supreme Court of Canada);
the claim had a real and substantive connection to Newfoundland; and
the Newfoundland court was the most convenient forum to deal with the claim.
On the first issue the court held that Sikorsky's actions with respect to HSI had constituted attornment. The court went through the jurisprudence on attornment and found that Sikorsky had gone beyond what was permitted (ie, merely challenging the jurisdiction of the court to deal with the claim that was issued) in order to avoid a finding of attornment.
On this point Justice LeBlanc took special note of the fact that Sikorsky not only opposed the discontinuance against HSI, but went so far as to seek (unsuccessfully) an order further barring the plaintiffs from commencing further proceedings against HSI on the theory that any such action should be taken in Connecticut.

On the issue of staying the matter pending the decision of the Connecticut court and the critical decision of the Supreme Court in Van Breda v Village Resorts Ltd (which is to be argued in March 2011), the court was equally unsympathetic. With regard to the Connecticut litigation, the court noted that although the decision was expected imminently, it was still outstanding and the judge in that case had indicated that further evidence and argument might be required before a ruling on that case could be made.

Regarding the Van Breda decision, the court noted that while the Supreme Court's decision would be relevant to the assessment of the matter of territorial jurisdiction, it was unlikely that the decision would be released until late 2011. Accordingly, LeBlanc decided that a temporary stay would not be appropriate given, among other things, the delay that would arise and the substantial losses that had been incurred.

On the third issue, the real and substantial connection to Newfoundland, LeBlanc placed heavy reliance on the test set out by the Ontario Court of Appeal in Muscutt v Courcelles, as modified in Van Breda. He found a real and substantial connection based on the following factors:

The courts of Newfoundland are presumed to have jurisdiction, as the rules of practice prima facie permit the service of a claim in that province (because it is a claim "founded on a tort committed in the province");
Although Sikorsky's defence relies (at least in part) on contract law principles, the claim is entirely founded in tort;
Although the crash did not occur in Newfoundland proper (it occurred 35 miles offshore), the alleged misrepresentations were relied on by Cougar in the province (where the most significant part of its business operates - even though the president of Cougar resides in British Columbia);
There were significant losses accruing to Cougar in the province - for example, lost profits, payroll and administration costs, public relations management costs, monies paid to families of employees and costs for search and rescue flights; and
In accordance with the Supreme Court of Canada's ruling in Moran v Pyle National (Canada) Ltd:
"[b]y tendering… products in the market place directly or through normal distributive channels, a manufacturer ought to assume the burden of defending those products wherever they cause harm as long as the forum into which the manufacturer is taken is one that he reasonably ought to have had in his contemplation."
Before leaving this issue, LeBlanc addressed the participation of the Lloyds 20 and the Lloyd's underwriters in the litigation. He noted that it was the claim itself and not the residence of the parties that established jurisdiction. In the case of Lloyds 20 and the Lloyd's underwriters, he specifically indicated that:
"the claim of Lloyds 20 and Lloyd's Underwriters cannot be seen to be separate and apart from that of Cougar. The claim of each of the plaintiffs is grounded on the same factual basis."
In determining the fourth issue - namely, whether Newfoundland was the most convenient forum to deal with the claim -LeBlanc noted first that, based on the jurisprudence, a party loses the ability to argue forum non conveniens once it attorns to the jurisdiction.

Regardless of the attornment, a review of the non-exhaustive list of factors set out in Muscutt, Van Breda and Teck Cominco Metals Ltd v Lloyd's Underwriters would lead to the same conclusion. The court agreed that Sikorsky would face additional costs litigating in Newfoundland, and that witnesses would have to be called from outside the jurisdiction. However, it held that:

the same would apply if the matter were heard in Connecticut;
the claim could be presented primarily through witnesses resident in Newfoundland;
it was unclear whether the laws of Connecticut would apply, given that the claim was founded in tort, not contract;
there would not necessarily be a multiplicity of proceedings, given that the Connecticut court had not yet ruled on the application before it;
if the action were pursued in Connecticut, the plaintiffs would be at a juridical disadvantage since, in that jurisdiction, they would be unable to recover pure economic loss in a product liability proceeding of this sort; and
the evidence from the Canadian regulators in this case would be more important than that from the Federal Aviation Administration.
Sikorsky's motion was dismissed with costs.

[maxwelg2]

Good to see the law actually working for us up here for a change.:D

Bring it on, this is what is needed to make SAC wake up and smell the coffee. The more media coverage and information sharing/awareness the better IMHO.

Safe flying

Max

[Mel Effluent]

More pressure on the certification issue reported here: Crash victims challenge S-92 certification: AINonline (http://www.ainonline.com/news/single-news-page/article/crash-victims-challenge-s-92-certification-29070/)

In an open letter to Canada’s minister of transport, the lawyer representing the families of the passengers killed in, and the sole survivor of, the March 2009 crash of Cougar Helicopters Flight 491 has challenged the certification Transport Canada granted to the Sikorsky S-92A in 2005. The accident helicopter, which ditched 30 nm east of St. John’s, Newfoundland, and Labrador, was carrying 18 people. Sikorsky declined to comment on the letter.

The letter was sent a few days after the Transportation Safety Board (TSB) of Canada released its final report (see AIN, March, page 51). Attorney Joe Fiorante asserted that the report does not satisfactorily address questions relating to the S-92’s initial certification. “Transport Canada should never have certified as airworthy a helicopter that could not fly for at least 30 minutes after the complete loss of main gearbox oil,” he stated.

Therefore, on behalf of his clients, he called on Minister of Transport Chuck Strahl to investigate the certification of the S-92. He urged him to “take all necessary measures” to ensure that, in the future, Transport Canada “rigorously enforces the safety standards.” He made it clear that the purpose of his request is to “advance aviation safety” and not for compensation purposes, as his clients’ legal claims have been resolved.

Transport Canada would not comment on the letter to the minister. The administration said that an official answer would be issued within 90 days after the TSB report was released (it was released on Feb 9). The agency also pointed out that it has already started implementing TSB recommendations, such as size selection for passenger survival suits.”

History of Failures

The survivor’s and victim families’ call for an investigation is based on a list of “incontrovertible facts.” First, Flight 491 crashed 11 minutes after, and as the direct result of, a complete loss of main gearbox oil. Canada’s airworthiness regulation requires that the main gearbox be able to run dry (that is, without oil) for 30 minutes. The only exemption is when it can be demonstrated that such a failure is extremely unlikely–no more than once per 10 million flight hours.

The lawyer emphasized that during the S-92’s development, Sikorsky had pledged that the helicopter would have this 30-minute run-dry capability. However, in 2002, the run-dry test resulted in a failure after only 11 minutes. Sikorsky then asserted the S-92 should be certified on the basis that the risk of complete loss of main gearbox oil was “extremely remote.” Both the FAA and Transport Canada accepted the conjecture, the lawyer wrote.

In July 2008, an S-92 suffered a complete loss of main gearbox oil. Fortunately, the aircraft landed seven minutes later. This incident demonstrated that the “extremely remote” assumption was erroneous, according to the lawyer. The S-92 fleet had logged a total 100,000 flight hours at that time. Transport Canada did not take any safety action, the lawyer pointed out.

Yet, after the crash of Cougar Flight 491, Transport Canada issued an AD requiring mandatory replacement of the titanium mounting studs that had failed and caused the oil loss. Sikorsky is looking for a better design. Nevertheless, the lawyer insisted, today the S-92still lacks 30-minute run-dry capability.

The letter also raised a question: “Did Transport Canada succumb to pressure from the FAA or Sikorsky, or did it simply fail to recognize a serious safety/certification issue?”

[Shell Management]

Finally, the FAA have actually certified the S-92 auto-hover that has been in use in Europe for years.:E

However, with the longer summer nights approaching it seems all the pressure is off Transport Canada approving the equipment for use in Newfoundland.:ugh: