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

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

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Old 30th Mar 2009, 05:51
  #261 (permalink)  
 
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pilotjoe,

its misleading to say that they continued flying problem for 10 mins 31 seconds, because they began a fairly rapid descent (over 1100 fpm) from 9,000 ft, which took the vast majority of that time and probably would not have differed much whether the crew intended to ditch immediately or not. There was only a little over 2 mins after leveling off at 800 ft until the power interruption to the FDR/CVR occurs, suggesting things went sideways pretty quickly.

the time frame for making critical decisions appears to have been pretty short, and i think second guessing actions made in those couple of minutes is a bit unfair to the crew.
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Old 30th Mar 2009, 06:28
  #262 (permalink)  
 
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I would have given it go at making dry land considering the proximity and thinking I had a 30 minute run dry gear box, until it became obvious I wasn't going to make it at which point being forced to ditch. The unknown for me in this thinking is how much time, between when the gear box starts making grinding noises and the power required to maintain RRPM starts going up, do you have to get it from that point to safely landed under control on the water? I dare say a lot less time than I expected.

I'm not a 92 pilot but I am surprised by revelations that it doesn't have a 30 minute run dry gearbox. I am a 76 pilot and I always assumed I had a 30 minute run dry gear box. Obviously I don't. So in light of all this and from here on, where the checklist says land immediately, that's exactly what I'll be doing.
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Old 30th Mar 2009, 08:10
  #263 (permalink)  
 
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truly sad times on our east coast
i hope our military is paying attention and insist changes are made before
taking delivery of their variant to replace the sea kings

good debate folks
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Old 30th Mar 2009, 09:39
  #264 (permalink)  
 
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The entire spectrum of causes will eventually be published once all the various analyses are completed by the appropriate authorities and other stakeholders.
However the “experts” of the actual operation itself are indeed ourselves, the folk that daily flog these machines to various locations full up with all those faces that we quickly forget.

With this in mind, I can’t hold back my curiosity any longer.


Two questions have been nagging me since the altitudes and timings were first published.

1: Why would an Offshore machine select 9000 AMSL as its cruising level over the open ocean?

By convention, most offshore altitudes are in the lower levels not the higher ones, and the reason given by most experienced offshore pilots: “Because it’s along way down should something go wrong”.

Surely the wind was not the only element that made the Captain select that altitude?

Could this aircraft have been flying in or above “Known Icing Conditions”, based on the weather and temperature of the day?


2: Why did the aircraft level out and increase speed at 800 AMSL?

I can appreciate the logic of “driving” a potentially damaged MGB with raw power to keep the Nr within limits, however I can’t rationalise why the aircraft was levelled at 800 AMSL. Any fall from 800 ft will hurt.

An altitude of 50’ AMSL seems a far more survivable altitude should an uncontrollable reducing Nr become the compromising element.

These and many other variations of these questions will be asked by numerous lawyers seeking the slightest crack in all the defences.
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Old 30th Mar 2009, 10:06
  #265 (permalink)  
 
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The RFM S92 (so therefore Cougar checklist??) states LAND IMMEDIATELY for the scenario the pilots faced.

Unlike the EC225 RFM, which says fly for 30 minutes at Vy, then LAND IMMEDIATELY.

Guess which one has 30 minutes run dry. There is no cover up by SAC as I do not think they have ever stated "30 minutes run dry capability", of course pilot perception is a different matter.

I'm not trying to defend SAC or the S92 gearbox, just trying to keep the debate on track
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Old 30th Mar 2009, 10:47
  #266 (permalink)  
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Dumb pilot answer to the reasonable question:
I just have to wonder what made them think they could get back to land with probably the most serious problem they could face, a failed MGB and the resulting deterioration of rotor rpm.
Perhaps they thought that they had that magical 30 run dry time. I have, on a few occasions, finding myself on the edge of the "approved" limit, counting on the actual certification requirement as my margin of safety. Perhaps these two unfortunate pilots also did!

I agree with Svenestron:
But I believe what is really misleading is the information out of SAC about the 30 min run dry compliance. Judging from the posts on here, most pilots seem to have understood there was a run dry capability when there was virtually none.
You can always argue it is there in black and white. But if a majority of pilots think differently, you have failed somewhere in communication.
I suspect that these pilots and passengers were cheated out of a margin of safety which they reasonably thought they had, which was not actually available to them. That's not right. Either the aircraft meets the design requirements, or it does not. If it does not, it flies with a limitation, and the pilots are boldly warned of the certification shortcoming.

Pilot DAR
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Old 30th Mar 2009, 11:53
  #267 (permalink)  
 
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Gullibell,

I too have held the idea of flying it till I "have to ditch" rather than "land immediately" as the checklists for many aircraft require.

How did so many of us arrive at that mindset?

How did we come to believe the transmission would give us plenty of warning before it made us passengers on a very terrifying but fatal thrill ride?

How did our system of training, checking, and engineering knowledge get supplanted by the existing Conventional Wisdom?

DAR,

Can you point out in any Training document or technical paper where the S-92 clearly states there is an allowable 30 minute run dry procedure?

Are there any Training Captains, Conversion Instructors out there that have stated during any training program, check flight, or tea room conversation that the S-92 has an authorized 30 minute run dry procedure when discussing the Emergency Check List?
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Old 30th Mar 2009, 12:02
  #268 (permalink)  
 
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OMR

Its not unusual to fly modern helicopters at high altitude, for the same reason that jet airliners fly high, ie much better fuel consumption for the same TAS, better VHF radio comms, better reception of VORs, smoother air etc

It might, as you suggest, also have had something to do with favourable tailwind and/or being above cloud / icing.

Yes it is further to fall, but that "should" not be a consideration!

HC
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Old 30th Mar 2009, 12:26
  #269 (permalink)  
 
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As much as i'm fairly sure i probably would have done very similar in their situation, the sad truth of it is as someone has mentioned,

If the POH states Land Immediately with the symptoms they had, and the pilots did not do it.

The chances are that Pilot Error will be applied to this case.

Sad but True

Chester
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Old 30th Mar 2009, 12:52
  #270 (permalink)  
 
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Regarding loss of the CVR/FDRs on the S-92:

1) Loss of two main generators, > Correction: FDR is on the battery bus
2) G-switch was tripped,
3) Immersion switch was tripped,
4) No APU generator. > Correction: FDR is on the battery bus

#3 can be ruled out.
#1 seems likely if mains overheated, mgb slowed dramatically, or mgb siezed. >Correction: Overheated main gens should have no effect
#2 seems unlikely unless mgb siezed catastrophically.
#4 is a mystery; APU should've been turned on with loss of mgb pressure. >Correction: APU gen should have no effect

Last edited by ArmchairExpert; 31st Mar 2009 at 00:28. Reason: Error correction...
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Old 30th Mar 2009, 13:32
  #271 (permalink)  
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Can you point out in any Training document or technical paper where the S-92 clearly states there is an allowable 30 minute run dry procedure?

Are there any Training Captains, Conversion Instructors out there that have stated during any training program, check flight, or tea room conversation that the S-92 has an authorized 30 minute run dry procedure when discussing the Emergency Check List?
Nope. And I'm not an S-92 expert either.

However, two thoughts:

A 30 minute run dry time has an allowable for damage to occur to the transmission during this time. Therefore it would not be "allowable" or "authorized" for normal operations, because, of course we are not "allowing" or "authorizing" operations which are likely to cause rapid damage to the aircraft. That's "emergency only" type stuff, requiring reporting afterward.

I know that during a certification test, the engine demonstrated safe operation at 105% of maximum speed, without an imminent unsafe condition.

"33.49 (6) A 15-hour run at 105 percent rated maximum continuous power with 105 percent maximum continuous speed"

So, if during a (admittedly poorly executed) manuever, I exceeded an engine speed limit by a few percent, (yup, I did, ONCE) I would not land immediately in an unsuitable area, or dangerous circumstances, I would fly it back to the most appropriate landing site, and report the exceedance.

Perhaps those unfortunate pilots could have set themselves up a bit better for success in a bad situation, I'm not here to judge that. But, I will judge a combination of certification testing/training/risk which entices a pilot to make a decision which is less than the best one. If there is NO margin for continued operation, the pilot has a right to know. Even "land immediately" suggests that some time will be required to execute a safe landing - 30 minutes perhaps? Maybe the term "land instantly" is what was really intended....

Pilot DAR
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Old 30th Mar 2009, 13:53
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How can you stretch "Immediately" to "30 minutes perhaps"?


im⋅me⋅di⋅ate⋅ly
   /ɪˈmidiɪtli/ Show Spelled Pronunciation [i-mee-dee-it-lee]

–adverb

1. without lapse of time; without delay; instantly; at once: Please telephone him immediately.
2. with no object or space intervening.
3. closely: immediately in the vicinity.
4. without intervening medium or agent; concerning or affecting directly.
–conjunction
5. Chiefly British. the moment that; as soon as.
Origin:
1375–1425; late ME; see immediate, -ly

Synonyms:
1. instantaneously, forthwith. Immediately, instantly, directly, presently were once close synonyms, all denoting complete absence of delay or any lapse of time. Immediately and instantly still almost always have that sense and usually mean at once: He got up immediately. She responded instantly to the request. Directly is usually equivalent to soon, in a little while rather than at once: You go ahead, we'll join you directly. Presently changes sense according to the tense of the verb with which it is used. With a present tense verb it usually means now, at the present time: The author presently lives in San Francisco. She is presently working on a new novel. In some contexts, especially those involving a contrast between the present and the near future, presently can mean soon or in a little while: She is at the office now but will be home presently.

Antonyms:
1. later.

Last edited by SASless; 30th Mar 2009 at 14:26.
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Old 30th Mar 2009, 14:13
  #273 (permalink)  
 
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So, if during a (admittedly poorly executed) manuever, I exceeded an engine speed limit by a few percent, (yup, I did, ONCE) I would not land immediately in an unsuitable area, or dangerous circumstances, I would fly it back to the most appropriate landing site, and report the exceedance.
pilotDAR. Are you saying that if you were knowingly faced with a situation that your company SOPs stated was LAND IMMEDIATELY, you would probably fly the aircraft back and mention it to someone?

If you are the you need some professional training. If you are not then your comments are at best misleading, personally I would say they are irrelevant and deserves the delete button.

Your two recent posts have me going
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Old 30th Mar 2009, 14:42
  #274 (permalink)  
 
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I'm curious to know where this sudden "Oh, all the pilots out there thought helicopters had a 30 minute run dry capability" came from? Is there a serious suggestion that Joe line-pilot sits and reads FAR Part 29 in the crewroom, maybe with a bit of AC29-2C for bed-time reading? Unless your RFM specifically states a period within which to have landed (like the EC-155 25 minutes I quoted earlier) assume nothing. Assume the RFM means what is says:

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

The moot point is the oft-quoted Fire Warning, and the sad thing about that, in this context, is that it can result from a single point failure, and is often spurious, so that tends to lead to a suspicion of the instruction to Land Immediately. Most other situations are the result of more than one indication, usually independant of each other (switches plus pressure transducer, for instance.)

Human nature and self preservation will generally dictate looking for signs to confirm that things aren't as bad as we think, and the more clues we see to confirm that, the happier we feel with continuing. It's self induced "risky shift." It's not a helpful trait, but it's a fact.

One of the by-products of improved reliabilty and reduced accident rates in the offshore sector - don't believe me? then check the UK AAIB archives for the 1980s and 1990s - is we are less exposed to either first hand accounts or writen reports. Maybe that has eroded some of the sense of danger we should all feel when confronted by these situations? A classic Catch 22!
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Old 30th Mar 2009, 16:15
  #275 (permalink)  
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Don't worry variable load,

I fly helicopters recreationally only...

Professionally, it is a part of what I do, to imagine the worst case, and choose wording for flight manual supplements, and maintenance manuals which will convey, with zero misunderstanding, to the reader, exactly what they are to do, and when.

You'd be surprised how many pilots have some familiarity with the design standards, and misuse them as over riding guidance for flying, without truly understanding the underlying meaning.

Too often in my 30 years of flying, I have found places where the instructions mislead the pilot or maintainer, and an unsafe situation existed. I make it my prime objective to get hte words right. That's often best done by understanding them wrong first....

I am probing. If the standard requires a demonstration of a 30 minute run dry time, all other things being non-factors, it should be at least plausibly possible, of why the words in the standard? If an apparent ten or so minutes (it could take that long to get down from up high) of continued operation is not safe (I'm not saying that you're not going to scrap a transmission, just get on the surface safely), more explicit wording is appropriate in Flight Manuals. "Immediately" sounds explicit, but it's true intent is apparently not being taken seriously. (by the way, I have never read an S-92 Flight Manual - just working with what I've read here).

I'm trying to figure out what works I should use in a Flight Manual Supplement, if I mean "go down from here right now, and don't stop 'till you get there"...
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Old 30th Mar 2009, 16:17
  #276 (permalink)  
 
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As details of the TSB investigation emerge and the oil company's joint investigation starts to grow momentum, we as offshore PAX now traveling by supply vessels are being told that S-92 testing is commencing this week in St. John's (I know it already commenced last Monday as I live on the test flight paths) with the view to move forward re-enstatement if the joint operator's decide that these helos are acceptably safe to use again. There are now more questions in my mind as more information and experiences/views come to light in these forums. Here are just a few...

How can this helo be considered safe for offshore use without the FAA re-approving/confirming the MGB dry-run capability (or lack of it) now that they are surely aware of the previous failure modes in Malaysia and Australia?

The RFM stated land immediately. Did the pilots assume that low MGB lube oil temperature due to sensor location meant that their press Tx sensor was faulty? Hopefully the FDR/VDR will answer this question.

Why is there no redundancy in MGB pressure and temperature sensors for such a critical component? Has the previous history of "nuisance" alarms with the S-92s caused mis-trust with the pilots not believing their instruments?

Is it not possible to "feel" a change in MGB performance with the high background quiescent vibration present in the 92s, or are you totally reliant on increased power consumption as your main secondary indicator?

Is vibration the main issue with the titanium filter bowl bolt failures, and can the steel variants fail due to the same inherent issue?

Why did the Blackhawk have steel bolts already and this was not passed on to the 92 immediately?

How can the Blackhawk have a 30-minute dry run capability if it is indeed the same MGB?

How good are the pilot's flight suits for offshore survival capability? Could this have had an effect on their decision to head for land?

As you can imagine we as PAX are still not convinced that the S-92 is suitable for offshore use. Unless the pilot can guarantee to me that he will ditch immediately on MGB oil pressure failure I will not be flying in the S-92 again. My life is more valuable to me than an offshore trip. The problem will be if we are told that this is our normal mode of transport to work and is deemed safe by all the official regulatory bodies, then it will be a hard call for some people to give up their offshore careers or accept the additional risk, which in this day and age should not be deemed acceptable.

Last edited by maxwelg2; 30th Mar 2009 at 16:33.
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Old 30th Mar 2009, 16:19
  #277 (permalink)  
 
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I'm trying to figure out what works I should use in a Flight Manual Supplement, if I mean "go down from here right now, and don't stop 'till you get there"...
Land immediately — Continued flight may not be possible. Ditching or landing in hazardous terrain is preferable to continuing flight.
Seems pretty clear to me and is more or less the same for all the types I've flown.

Maxwel,
all I can say is that we as pilots DO climb into this aircraft, and fly it several hours per day, and that should be your re-assurance. To put it in context, would you fly in a Boeing 777, after all there are 220 of them in current service with a known engine roll back problem that will take over a year to fix? If you flew in an MD-11 would you ask the pilot to fly not above 20,000 ft, as the Swissair could never have descended to safety from their cruise altitude following their fire? and so the list goes on.

For the sake of clarity/accuracy, there was not a similar incident in Malaysia, only Australia.

Last edited by 212man; 30th Mar 2009 at 16:31.
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Old 30th Mar 2009, 16:48
  #278 (permalink)  
 
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212man, I accept a degree of risk in any mode of transport I use and most certainly you as a pilot accept an even greater degree via the additional flying hours spent in these helos, but as a PAX and using this transport as my only regular mode of transport to working offshore (weather-permitting) it is up to the operator and client (oil company) to ensure that this helo is as safe as is reasonably practical. IMHO if it is proven that the S-92a does not comply with FAR29/CS29 then this breaches this requirement. I'm quite sure that the impending lawsuits by the bereaved families will view this in a similar manner...

Wrt. the Malaysian MGB failure I accept that this event was not the same as Broome or flight 491, but the same issue of MGB reliablility is still valid. I did not mean to imply that it was the same common mode of failure. I appreciate that you have real first-hand experience of that particular incident and know only too well the limitations of the S-92 MGB design. I'm just not confident that SAR and the FAA are being proactive enough with this helo to iron out it's weaknesses and make it legally compliant with the applicable safety standards.

It is everybody's decision what they choose to accept as safe or unsafe, at present I'm on the fence with the S-92a. I would fly in a S-61 or Super Puma Mk2 any day, as I have done over the past 18 years with no qualms. I trust the pilots first and the aircraft second, always have.
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Old 30th Mar 2009, 17:16
  #279 (permalink)  
 
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I would fly in a S-61 or Super Puma Mk2 any day
maxwelg2, whilst I fully understand the emotion and associated apprehension with the S-92 in St Johns, I hope you do not object to me mentioning that neither of those aircraft have any certified run dry capability either.

I fact the S61 has a known MGB failure mode that has resulted in two aircraft burning to the keel in a couple of minutes.

Sometimes things aren't as simple as we like to make them.....
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Old 30th Mar 2009, 17:29
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That may be the case, but statistically and IMO they stay in the air a lot better and have some level of MGB lube oil redundancy i.e. AS332L Glycol cooling, S61 DC aux lube oil pump from lower sump.

I can remember the old Tigers and Mk1 Pumas having gearbox chewing issues in the early 90s in the North Sea and having the odd drip of oil from the chip detector access panel on my survival suit, I'd like to think that in the 21st century helos were being built with a higher safety factor.

I recall reading on one of the posts of the 30-minute dry run capability being a requirement from 1988, are we still to believe that the S-92 still avoids this requirement on the "extremely remote" wording?

Last edited by maxwelg2; 30th Mar 2009 at 18:17.
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