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-   -   Air NZ 787 RR engine issues (https://www.pprune.org/rumours-news/602829-air-nz-787-rr-engine-issues.html)

fleigle 23rd April 2018 14:59

The oscillating rotary swivel pins for the 5th. stage stator assemblies were machined incorrectly and require removal and replacement.
:{:{:{
:E
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lomapaseo 23rd April 2018 16:24


What is the actual work required on theengines ? Is it fully identified, and how long does it take ? Is there a production line set up for the work, and is the fix permanent ?
This should be laid out in the available comments to the actual Airworthiness Directive issued by the authorities.

No need to ask RR

underfire 23rd April 2018 18:15

Just curious, I have a friend planning the SYD to SFO on United 787-9 near the end of May...think I should suggest they reschedule as the ac may not be able to fly this?

tdracer 23rd April 2018 18:35


Originally Posted by underfire (Post 10127942)
Just curious, I have a friend planning the SYD to SFO on United 787-9 near the end of May...think I should suggest they reschedule as the ac may not be able to fly this?

Given that United has GEnx engines on their 787 fleet, I wouldn't think a Rolls engine problem would affect them :hmm:

coboltblue 23rd April 2018 20:24

Rolls definitely seem to have been in the doghouse of late. They apparently missed the boat when it came to business jet engines then failed to properly plan for the phasing in of the Trent 1000 engines. Their marine division has been losing money for a while as well, there is talk they might have to sell this part of the business.

They also have an activist investor on the board, sometimes these guys are good for a company, but equally sometimes there not!!

underfire 24th April 2018 01:00


Given that United has GEnx engines on their 787 fleet, I wouldn't think a Rolls engine problem would affect them
actually, thanks for the info!

Deepinsider 3rd May 2018 12:00

The NZ Transport Accident Investigation Commission has published an initial report which has accurate info about the two failures
and some more info about the newer compressor faults.
Google them ; New Zealand Transport Accident Investigation Commission AO-2017-009
(report under document downloads)

Dee Vee 3rd May 2018 22:03


Originally Posted by Deepinsider (Post 10136962)
The NZ Transport Accident Investigation Commission has published an initial report which has accurate info about the two failures
and some more info about the newer compressor faults.

Is anyone else appalled by this "Political Correctness" Speak?


The incidents occurred when blades failed earlier than predicted by Rolls-Royce’s risk analysis modelling for the known issue.
Blades aren't designed to fail! And in normal circumstances would have been replaced long before their use-by date. Rolls Royce has been aware of this issue for years. Plenty of time to fix the issue.

lomapaseo 3rd May 2018 23:43


Is anyone else appalled by this "Political Correctness" Speak?

Quote:
The incidents occurred when blades failed earlier than predicted by Rolls-Royce’s risk analysis modelling for the known issue.
Blades aren't designed to fail! And in normal circumstances would have been replaced long before their use-by date. Rolls Royce has been aware of this issue for years. Plenty of time to fix the issue.
I don't get your point about PC speak. RR got one of their assumptions wrong about the harshness of the environment they fly in. They revisited and updated their assumption and hence the announced SB in order to continue flying safely.

I don't know how else this should have been stated.

Dee Vee 3rd May 2018 23:54

[QUOTE=lomapaseo;10137444I don't know how else this should have been stated.[/QUOTE]

These blades have been "self destructing" for 2 years now, to say they are failing earlier than expected is nonsense. People lives are being put at risk.

They should be saying "our design/engineering team got it badly wrong, all these engines should be taken out of service immediately until a proper and permanent fix can be installed, Rolls Royce will compensate everyone for our poor practices and "agile" development pushing these things out before they were ready and properly tested".

tdracer 4th May 2018 00:19

Gee Dee Vee, don't mince words, tell us how you really feel :sad:
What Rolls is doing is common practice in the industry. The have a part that's failing prematurely. They analyze the problem with all the available data - since this is basically a 'wear out mode', they determine how many hours/cycles the part can take before there is a significant risk of failure. They put some safety pad on the numbers and say something like 'after xxxx cycles (or hours), inspect to make sure the part is still healthy - if it's not take it out of service, if it's OK you can operate another xxx cycles then inspect again. This happens on a regular basis, to every engine manufacturer (not to mention the rest of the aircraft), and 99.9% of the time it works fine and most people never even know it's going on.
This time, Rolls botched the analysis and the part is failing much faster than they predicted - whoops... Worse, they also determined that there is a resonance issue that can cause an engine to fail prematurely when operated for an extended period at max con power - double whoops. So they updated their analysis based on the latest data - and updated the requirements accordingly to maintain safety.

You apparently take issue with the process - well lets consider the alternative. Every time we discover an issue with an aircraft component, we ground the whole :mad: fleet until a fix is identified and implemented. We would all just stay home because no one would be able to fly, and everyone in the industry would be bankrupt or unemployed.

Dee Vee 4th May 2018 00:27


Originally Posted by tdracer (Post 10137455)
Gee Dee Vee, don't mince words, tell us how you really feel :

Don't you think Rolls Royce are playing down the problem?
  • They didn't do sufficient testing before they pushed them out the door.
  • When issues started occurring they declare its a minor issue, and the parts are wearing out prematurely, rather than an inherent design issue
  • The will get around to fixing it at their leisure, shouldn't be a problem as long as the other engine is still working.
  • 2 years down the track we are still getting engine failure occurring.
Do people have to die before its taken seriously?

lomapaseo 4th May 2018 02:30

Dee Vee
There are operators involved here as well as the airplane maker. It's there problem when it goes tits-up. So no, RR isn't playing it down, they are responsive to the end user and regulator far before you get on a plane..

As for sufficient testing ? it takes years to illustrate a wear out mode failure and to accommodate this all engine manufactures follow the same protocol in running engines very hard for hundreds of hours before they are certified, so no short cuts here.

From the millions of hours of industry wide experience on all engines, a turbine blade failure condition is typically classified as a minor failure condition, it's only when two engines may get involved that it moves up notches.

The rate at which a fix gets incorporated is driven by the safety aspect and the operator's ability to absorb engines out of service. All RR can do is throw money at it beyond assigning engineers to work the job.

Yes the issue is that after 2 years we are still experiencing too many failures $$$ and pushing the risk of 2 engines so back to the snake pit of more pain to both RR and its operators

At this point the data certainly doesn't indicate that this problem is so far out of hand that a catastrophe has risen to the top of the inherent risk of flying.

back to Boeing 4th May 2018 02:33

Don't be so overly dramatic. On the one hand Rolls pushed the design as hard as they could to make the best engine they thought they could. They probably pushed it too far, like lots of items on the 787 (battery fired anyone).

On the the other hand Boeing shut down further development of all components when they fixed the design earlier than they should have. Like all new aircraft the 787 was delayed. Previously further testing would have been allowed and this issue could possibly (not certainly but possibly) have been caught. But Boeing allowed no further development of any components. Which in itself isn't a bad thing considering that all the components were coming from different manufacturers all around the world. At some point development had to stop. Unfortunately this time it bit them in the ass.

Rolls, Boeing and the airlines involved are working damn hard to fix the issue. But it will take time. I'm the mean time the regulators have placed restrictions and testing to examine, trap and mitigate the problem.

Deepinsider 4th May 2018 10:50

[QUOTE=Dee Vee;10137393]Is anyone else appalled by this "Political Correctness" Speak?

Sorry Dee Vee that you didn't like the way I worded this. I'm on the same side as you, and
the reason I worded it so, was that until this publication we only ever got statements from
the PR (b.s.?) departments of RR and operators. I was trying to show that this item was
Actually Factual.... and not massaged by the PR b.s. that had so far clouded/avoided the truth.
.

infrequentflyer789 4th May 2018 13:48


Originally Posted by Dee Vee (Post 10137458)
Don't you think Rolls Royce are playing down the problem?
  • They didn't do sufficient testing before they pushed them out the door.
  • When issues started occurring they declare its a minor issue, and the parts are wearing out prematurely, rather than an inherent design issue
  • The will get around to fixing it at their leisure, shouldn't be a problem as long as the other engine is still working.
  • 2 years down the track we are still getting engine failure occurring.

Are you sure you're talking RR and not CFM here ?


Do people have to die before its taken seriously?
They already have... and the self-destructing CFMs sure as heck haven't been "taken out of service immediately until a proper and permanent fix can be installed".

Right Engine 10th May 2018 12:49


Worse, they also determined that there is a resonance issue that can cause an engine to fail prematurely when operated for an extended period at max con power
The opposite is true. The resonance occurs at LESS than Max Continuous power. If you read the Boeing Bulletin you’ll see that in the event of an Engine Failure crew must operate the aircraft during the subsequent diversion and do it at as high a FL as possible to keep the remaining engine out of the resonance ‘range’ and close to MAX CON.

WHBM 11th May 2018 00:14

Rolls-Royce Chief Operating Officer fired

Rolls Royce operations head Simon Kirby to leave in summer after only 19 months in role | City A.M.

Deepinsider 12th May 2018 11:24

Was his role instrumental in this product design/support disaster, or is he just unlucky with the restructure timing?

(either way, it will be very tricky writing his next CV
Noting infrequentflyer789 comments, someone from CFM might well be needing CV advice too!)

WHBM 12th May 2018 11:40


Was his role instrumental in this product design/support disaster, or is he just unlucky with the restructure timing?
Well, it can be a couple of things. One is that when executives are in a "musical chairs" for a reduction in the top positions, costs not exceeding budget is one of the key aspects that everyone looks at, and some significant unbudgeted problem product cost is just something nobody wants to sign off. The other is that while all this is going on, the people at the top are distracted outside their normal day-to-day responsibilities, while those beneath them can become unnerved for their job stability, and of course it's your best people who are most attractive to other organisations.

It also happens that the rest of The Board see someone being too frugal with things and upsetting the whole name and image of the business.


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