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

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.

Mrgb after loss of lube
 

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.

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?

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

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

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!).

= 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

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.

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.

Thanks for that. Will it be webcast too?

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.

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.

Land As Soon As Possible - Land Immediately
 

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

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

So if we are off-shore

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

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

$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

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

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

Land as soon as possible.
 

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.