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Old 13th Feb 2005, 00:34   #41 (permalink)
 
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Bristow EC-155's eating engines at a whopping rate!

Whilst roaming through the HAI floor last week.....overheard a conversation that reported Bristow Nigeria's Shell owned...OLOG operated EC-155's have now done over 200 engine replacements for all manner of causes. That makes one wonder more than a bit about the reasons.....maintenance, pilots, training procedures, or design problems?

Way back...the Bristow Nigeria S-76 fleet also was going through engines by the boatload until they discovered the engine wash water was very saline (hate to use the phrase saltwater here) and that was causing a wee problem for them.


Wonder if someone close to the situation can explain the situation?
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Old 13th Feb 2005, 04:51   #42 (permalink)
 
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I heard of a Swiss gentleman who bought a new 155 and had an engine change within 2 weeks, just wasn't making the required power.
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Old 13th Feb 2005, 09:39   #43 (permalink)
 
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Have also heard that new S76 C+'s are only getting about 600hrs out of there Arriels, as I have said in other posts the french engines don't like hot climates , and the arriel 2 is pushed to the limit, Turbomeca are renouned for sending out engines from new or O/haul which fail on thermal load after a very short time, then try and get a responce from the French ; (But sir the engine was in spec when it left our workshop (with suitable french accent))
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Old 13th Feb 2005, 09:53   #44 (permalink)
 
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Wake up Sikorsky.

When are you going to realise that the French Engine is a Hybrid and wonít do its full days work?

Start looking at the C47 or LTS for the 76, or the client base will start looking elsewhere.

Where I donít quite know yet, but not at the French thatís for sure.
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Old 13th Feb 2005, 11:22   #45 (permalink)
 
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First I heard that anyone Swiss had bought one?
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Old 13th Feb 2005, 11:38   #46 (permalink)
 
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212man....your profile says you drive 155's in Nigeria.....anything you can add to this discussion? Any sort of empirical data you can share.....for those of us that are operating 155's in hot offshore places....in the Gulf of Mexico we are being confronted by the same thing on the two 155's operating there.

What is causing the unusual number of engine changes? Shell is supposed to be the fleet leader in hours now....and in Nigeria...that means Bristow thus it would seem you might know something that could help the rest of us.
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Old 13th Feb 2005, 12:02   #47 (permalink)
 
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SASless, if I could tell you what the problem with the Arriel 2 series is I think I'd be knocking on Turbomecca's door with a suggested consultancy fee!

I seriously doubt the 200 figure, but stand to be corrected.

I think it's well known that the Arriel 2 is working hard and is probably at the top end of it's development process. The 76 C+ has had similar tales of woe with power assurance figures too.

The reality is that 155/76 size helicopters probably need an engine in the TM Ardiden category (the derivitive of the TM-333). There is a gap in the market at present between Arriel size and PT-6 size and maybe it will fit it.

I take it from your comments that you are now in Texair, or was that the 'royal us' ?
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Old 13th Feb 2005, 12:10   #48 (permalink)
 
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Are the engines being replaced...sent off to Turbomeca...overhaulled and sent back....with hot end changes or something similar? Any identifiable issues that could help point other operators towards the paths of rightousness or is it simply a bad engineering decision by the builder to use that particular engine?

You are correct that the 76 using the same engine is encountering problems with the engine making TBO....which seems to confirm your observations.

You might be closer to that consultancy than you think....but not with Turbomeca.
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Old 13th Feb 2005, 14:29   #49 (permalink)
 
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The Arriel 2 series engines fitted into any helicopter operating in hot climates seems to have a problem. Bristow have had to replace many engines in their EC155s in Nigeria, ACN have had to replace many engines in their S76C+s in Nigeria and Schreiner had to replace both engines in their 365N3 in Cameroon. I heard that the same problem exists/existed in Hong Kong and Macao - anybody working there care to comment? What about the machines in Dubai as well?

If only P&W could come up with an updated engine for the 76B, producing about the same power for a similar fuel burn to the Arriel 2 series, Sikorsky could ditch the problematic Arriel 2 series engines (though I'm sure Eurocopter will always go for a French engine over an American one )
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Old 13th Feb 2005, 14:46   #50 (permalink)
 
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I would put money on Eurocopter putting the Ardiden into an EC-155B2 or 3 within 3-4 years. It will transform it.

Sasless, no point fishing from me I'm afraid; you won't get anything I consider confidential.
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Old 13th Feb 2005, 15:49   #51 (permalink)
 
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212man....last time I checked....OLOG/Bristow operates Shell owned 155's....you guys are mere caretakers of the equipment....thus no competitive advantage there in my view.

Certainly we would not want you to give out proprietary information....but the same information that would go into a MMIR or a government publication surely is not "confidential". We are talking about generic problems that all operators of a common aircraft type are having......ever sat in on a Technical briefing at the HAI for example....the manufacturers are very forthcoming about these kinds of things....and they are open to the public...no invite required...no entrance fee....just walk thru the door. I found the feedback given and received by the operators and manufacturer to be very helpful last week. Engine issues with the C+ was discussed....that led to the conversation about the 155 and its engine issues. No secrets at Sikorsky....why at your end?

Why do you appear reluctant to discuss straight forward technical issues? You are in a position to relate much the same kinds of information that Nick does for the S-92 and S-76, and would not reveal sensitive company information while doing so.

Or do I misunderstand your position?
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Old 13th Feb 2005, 16:31   #52 (permalink)
 
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SASless,

You have to accept that if the data is harmful to someone's position, it won't be given out, at least in some circles.

Best to assume it is bad enough to want to clam up.
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Old 13th Feb 2005, 16:55   #53 (permalink)
 
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Mama M

P&W are doing it!

PW210S will power the S76D in 2008, with 1000-1100 SHP and lower or equal fuel burn as the Arriel.

Will it work, time will tell.



CB
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Old 13th Feb 2005, 17:14   #54 (permalink)
 
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Gentleman,

I am not a guru on the Arriel 2C or 2S series engines but I can offer some explainations based on my experience with the 2B series which is very close.

When the engine is calibrated on the test cell they actually bend slightly the nozzel guide vanes. After a short time (within 700 hours or so from new) the NGV seems to open up just a bit which reduces power and makes the engine run cooler. Turbomeca has figured this out and changed the test cell criteria such that an engine with 700hrs does not fail a power check. Now the engines right off the test bench make a good bit more power and therefor run a touch hotter. Normally this is not an issue but if you are running in a high temp environment you could be pushing the T4.5 limits right from the start. The folks in the shop are given a range to shoot for when calibrating an engine and they have to guess at the type of environment you will be operating in so they can produce an engine that fits your needs. Unfortuantely until recently they were not getting much feedback from the field as to where their best guess was hitting. They have to use Kilowatts and T3 temperature in the cell where as on the aircraft with installation losses and corrections the numbers may change. The test cell guy doesn't know that so many KW and so much T3 is going to equal a certain amount of Tq margin and T4.5 margin in the aircraft. They are getting this info now so they should be able to set the engine up a little better in the future.

The Arriel 2 series in general is still a fairly young engine and of course has had it's growing pains. As was mentioned previously it is getting near it's upper power limits which creates some challenges. Another issue that has become a problem is premature engine removal. Since the engines are FADEC controlled some of the old school type maintenance staff would rather change an engine than troubleshoot to see where the problem really lies. I don't want to accuse anyone of this as most of the maintenance folks I have met are top notch but it does happen. I have seen several engines removed for indication problems and lack of troubleshooting. This situation as well is getting better but the damage to the statistics is probably already done.

I would be happy to unofficially try to answer any specific questions if I can but as I said I am not the Arriel 2S or 2C authority.

Best Regards,
MaxTork
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Old 13th Feb 2005, 18:01   #55 (permalink)
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So explain this to a non pilot.
Why then do they not install a bigger power output engine in the first instance or, issue an AD? that in places where temperatures are consistantly above a fixed point a different set of donkeys should be installed.
Note the smart use of a colloquialism, why go out more when the worthy PPRuNe subscribers are so informative.
And don't just respond with the word MONEY for if the helicopter is on ground and not earning, it's costing money.
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Old 13th Feb 2005, 18:14   #56 (permalink)
 
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Captain N

Unfortunately Money is the big factor here. Sikorsky and Eurocopter ask for an engine that makes XYZ power at XYZ temps and that is wht the engine guys have to provide. If this turns out to be not enough for some instances then so be it. It would be up to the airframer to certify a new engine in their aircraft just to meet the needs of the few operators who work in high temp areas. If they were to do so then it would make sense to put the same high output engines in all the airframes. This is very much what was mentioned earlier in this thread about the Ardiden engine which will be much more powerful than the current Arriel. Not to mention all this hot rodding we talk about in making more power from an engine has consequences too. More power means more stress on a gearbox and airframe which takes modification as well. It is very much like building a race car...bigger engine means stronger transmission and driveline then a rollcage for stiffness and so on....do you see the snowball getting bigger? As much as I hate to say it if you want a bigger snowball you better have a bigger pocket book.

MaxTork
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Old 13th Feb 2005, 18:22   #57 (permalink)
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Thank you Maxtork.
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Old 13th Feb 2005, 21:19   #58 (permalink)
 
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Capt. Notarious,
Its not so much about the power but (as Mama Mangrove correctly stated...) its all related to the fuel burn.
If they could, they would probably fit the PT6 and be done with it. Canadian motors rock...

However, an S76 or a 155 are going to suffer a dramatically reduced range and be economically impractical. Hense the reason that the S76B model is largely a corperate machine these days. It has the fuel hungry engines.

The other issue is that big motors weigh more, cost more and can lift more. Larger motors will encourage the customer to ask for more payload and any advantage of the power surplus is soon absorbed in payload increase.

EG: The C model 76 has the 1S1 and has always been N1 and temp limited. The solution for this was the 2S1 engine in the C+. Better OEI and hot and high performance...
Does anyone know the operating specs of the C+?, the MAUW of the C model was 11700lbs. Any changes to that?
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Old 13th Feb 2005, 21:27   #59 (permalink)
 
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I dare say the EC-155 purchase by Shell was not based upon any kind of efficency study....quite the contrary. The Bell 412 that showed up at Redhill with all the fancy kit, buttons, knobs, and dials was not even looked at. That was a Shell decision....not a Bristow one.

The 155 was to replace the 212....but cannot carry the people and baggage the 212 does....one cannot load passengers and baggage simultaneously as you can on the 212.....the 155 requires much more "runway" to operate than does the 212. We even did a VIP run into a ball field because the 155 could not operate into the place.

The 155 is faster, smoother, has all the fancy kit....but is not the aircraft the 412 is for offshore or utility type flying.

Ask 212man about the new runway being built at Warri to replace the 212 site that has been used for ages so the 155 can legally operate out of the Shell IA. All of that is a function of engine power or the lack of....
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Old 14th Feb 2005, 15:15   #60 (permalink)
 
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SASless

There is one big fact you have been over looking. The B212 was never operated to Cat A performance specs. The EC155B is required to meet Cat A. Granted this must be achieved using a much different takoff and landing profile. I loaded passengers just the other day at the same time. It just has to be from both sides of the A/c. Which the 212 can't do if someone is in a well seat. I think if they had the performance charts to operate to Cat B for the EC 155B you'd find it performs just as well as a B212.
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