ANA to inspect engines on 787 fleet, some flights cancelled over coming weeks

B787register · Thu Aug 25, 2016 12:14 pm

a lot of news stories this afternoon in regards to ANA grounding the 787 fleet due to major engine issues. they are to hold a press conference soon. does anyone have any further information

KarelXWB · Thu Aug 25, 2016 12:16 pm

It's not as bad as it sounds. From Reuters:

Japanese carrier ANA Holdings (9202.T), said on Thursday it needs to replace damaged compressor blades in the Rolls-Royce (RR.L) engines powering its Boeing (BA.N) 787s, forcing it to cancel some Dreamliners flights over the coming weeks.

The carrier said that under certain flying conditions the compressor blades in the engine's interior showed corrosion. It said it will cancel nine domestic 787 flights on Friday, with other cancellations likely in the coming weeks.

...

ANA said vibrations resulting from the problem with the compressor blades had occurred on a flight from Japan to Malaysia in February and on one to Vietnam in March. A 787 traveling on a domestic route on Aug. 20 had also experienced trouble, it said.

http://www.reuters.com/article/us-ana-r ... SKCN1100X3

Amiga500 · Thu Aug 25, 2016 12:19 pm

KarelXWB wrote:
It's not as bad as it sounds. From Reuters

I dunno - that reads pretty bad too.

It'll light a fire under R-R that's for sure.

[and expect the stock market lemmings to blame Boeing for it as usual.]

KarelXWB · Thu Aug 25, 2016 12:24 pm

Well they are not grounding the entire fleet, just a few aircraft.

B787register · Thu Aug 25, 2016 12:50 pm

which ac are grounded ?

KrustyTheKlown · Thu Aug 25, 2016 4:05 pm

I wonder what's special about the grounded aircraft, could they be old frames, were they outfitted with a PIP or they have production numbers that can be traced to a manufacturing/maintenance error?

Revelation · Thu Aug 25, 2016 5:18 pm

KrustyTheKlown wrote:
I wonder what's special about the grounded aircraft, could they be old frames, were they outfitted with a PIP or they have production numbers that can be traced to a manufacturing/maintenance error?

I also would like to know more.

All the Reuters article says is "a spokesman said the issue was limited to a small proportion of the ANA fleet" and that spokesman was from RR.

The article also said:

The carrier said that under certain flying conditions the compressor blades in the engine's interior showed corrosion

and

ANA said vibrations resulting from the problem with the compressor blades had occurred on a flight from Japan to Malaysia in February and on one to Vietnam in March. A 787 traveling on a domestic route on Aug. 20 had also experienced trouble, it said.

so we know the symptoms are vibrations due to corrosion in the compressor blades, but we don't know the root cause (design issue, manufacturing issue, materials issue, etc).

spacecadet · Thu Aug 25, 2016 8:35 pm

Let's not forget about this: http://www.avherald.com/h?article=49c93f39&opt=0

Not *necessarily* related, but "metal debris reportedly blades from the engine needed to be removed from the runway."

Stitch · Thu Aug 25, 2016 10:09 pm

Amiga500 wrote:
KarelXWB wrote:
It's not as bad as it sounds. From Reuters

I dunno - that reads pretty bad too.

It'll light a fire under R-R that's for sure.

It sounds similar to a corrosion issue in the crown wheel gear of the transfer gearbox that adversely affected ANA more than other Trent 1000 operators in 2012.

ANA is more-affected by these corrosion issues because the issue is exacerbated by shorter flights, so it appears that ANA's domestic 787s are the ones that are experiencing the issue as the engines are not operating long enough to evaporate the moisture in the exhaust and when on cool-down, that moisture condenses again and contributes to continuing the corrosion.

RL777 · Fri Aug 26, 2016 1:37 am

Can't comment on the depth of the issue, however I have heard that NH may swap back to the 763 to YVR during the coming weeks until a few 787 frames are back & running.

747classic · Fri Aug 26, 2016 2:10 pm

It seems that ANA cancelled 9 B787 flights for today (Friday) and expects to cancel over 300 flights until the end of September.

See : http://www.bloomberg.com/news/articles/ ... tire-fleet

JerseyFlyer · Fri Aug 26, 2016 2:59 pm

Appears under control:

"Rolls-Royce said it had notified other airlines that use the same type of engine, adding that it would make an improved part available by the end of the year."

https://www.theguardian.com/world/2016/ ... ne-problem

Revelation · Fri Aug 26, 2016 3:18 pm

JerseyFlyer wrote:
Appears under control:

"Rolls-Royce said it had notified other airlines that use the same type of engine, adding that it would make an improved part available by the end of the year."

https://www.theguardian.com/world/2016/ ... ne-problem

That article is filled with hype.

WIederling · Sat Aug 27, 2016 7:47 am

Revelation wrote:
https://www.theguardian.com/world/2016/ ... ne-problem

That article is filled with hype.[/quote]
??

a brake computer fault

that one is new to me. the rest is "well known issues" and they happened more than once each :-)

VirginFlyer · Sat Aug 27, 2016 10:25 am

WIederling wrote:
Revelation wrote:
JerseyFlyer wrote:
https://www.theguardian.com/world/2016/ ... ne-problem

That article is filled with hype.

??

a brake computer fault

that one is new to me. the rest is "well known issues" and they happened more than once each

The article lost me with special mention of a cracked cockpit window (as if this is something fairly unique to the 787)

V/F

StTim · Sat Aug 27, 2016 10:29 am

At one point there was a rash of cockpit windows cracking. This was either a statistical anomoly or there was an issue and there has been a change to reduce to normal. Hardly earth shattering though.

Revelation · Sat Aug 27, 2016 12:24 pm

StTim wrote:
At one point there was a rash of cockpit windows cracking. This was either a statistical anomoly or there was an issue and there has been a change to reduce to normal. Hardly earth shattering though.

Shattering? I see what you did there....

StTim · Sat Aug 27, 2016 12:34 pm

Revelation · Sat Aug 27, 2016 12:47 pm

WIederling wrote:
Revelation wrote:
https://www.theguardian.com/world/2016/ ... ne-problem

That article is filled with hype.

??

http://www.dictionary.com/browse/hype gives us a definition of "hype" in the noun form as "exaggerated publicity; hoopla".

Hope this helps.

PW100 · Sat Aug 27, 2016 2:43 pm

Revelation wrote:
http://www.dictionary.com/browse/hype gives us a definition of "hype" in the noun form as "exaggerated publicity; hoopla".

http://www.dictionary.com/browse/rhetorical-question?s=t

Revelation · Sat Aug 27, 2016 3:12 pm

PW100 wrote:
Revelation wrote:
http://www.dictionary.com/browse/hype gives us a definition of "hype" in the noun form as "exaggerated publicity; hoopla".

http://www.dictionary.com/browse/rhetorical-question

Just trying to be sensitive to the fact that English is not the first language for many here....

WIederling · Sun Aug 28, 2016 8:00 am

Revelation wrote:
Just trying to be sensitive to the fact that English is not the first language for many here....

All I wanted to say was that
A: I did not find the article all that much "hypish".

B: I had not noticed the "brake computer glitch" issue before.
either overlooked on my side or kept rather well under wraps.
( Boeing seems to have invested quite a bit on keeping the
lid on problems after the batteries standstill got too much
unwanted attention.)

Revelation · Sun Aug 28, 2016 12:33 pm

I re-read the articles posted earlier, and in particular the Bloomberg article seems to have a lot of discussion about how corrosion can happen in jet engines.

Flying shorter flights would produce more wear and tear on an engine designed to spend 10 or more hours cruising between continents, said Robert Mann, an aviation consultant. Corrosion caused by sulfides could be caused by the “combination of higher temperature stresses in the climb portion” of flight, followed by shorter than typical periods at cruising altitude, he said.

Mann likened the situation to the pressure on the exhaust system of a car driven only short distances. “The engine never heats up fully to drive the moisture out the exhaust system. Then it shuts down and condensation causes the rust to gather,” he said.

It's hard for me to evaluate such a statement. Without having any expertise I would guess that pretty much any commercial flight's climb to altitude would heat the engine sufficiently to drive out moisture, but then again, that could be naive. Clearly flights that don't climb as high and have less pax and payload cause different heating than those that are full.

Maybe some of our subject matter experts could tell us more about corrosion in jet engines?

WIederling wrote:
I did not find the article all that much "hypish"

That's fine, we're here to share our opinions, but in comparing the three articles posted here (Reuters, Bloomberg, Guardian) I disagree with your opinion.

For instance, compare the three headlines:

Reuters: "Japan's ANA finds problem with Boeing 787 Rolls-Royce engines, cancels some flights"
Bloomberg: "Rolls-Royce Engine Corrosion Spurs ANA to Check Dreamliners"
Guardian: "Japan's biggest airline grounds its Dreamliners over engine problem"

As mentioned above, the article spends a lot of time talking about many of the 787's earlier issues that don't have any connection to this one (such as cracked windshields), and IMHO not a lot talking about the current issue.

Tedd · Sun Aug 28, 2016 3:21 pm

"Sententiousness" sells newspapers!

PW100 · Sun Aug 28, 2016 9:38 pm

Revelation wrote:
It's hard for me to evaluate such a statement. Without having any expertise I would guess that pretty much any commercial flight's climb to altitude would heat the engine sufficiently to drive out moisture, but then again, that could be naive. Clearly flights that don't climb as high and have less pax and payload cause different heating than those that are full.

I read this as a "Sulphidation" problem on one of the turbine stage blades, also referred to as "Hot Corrosion". This is not related to moisture. The corrosion agent is sulphur, which can originate from the environment (particles hanging in the air) and/or jet fuel.

Another important characteristic, is that this "corrosion" process only occurs in a very narrow temperature band, and can be quite difficult to predict how it will develop. Usually it will take thousands of hours and//or cycles (sometimes even 10000+ hrs/cls) to develop, and thus can take quite some service time before showing up.
High-cycle operations iare more vulnerable as they spend more (relatively) time at low altitudes where air pollution (smog) induces sulphidation.

Once sulphidation has been established, a soft and hard time limit will probably be applied to subject blade part numbers. It seems that initial conservative time limits have been set.
ANA, as an early and large operator, will probably have quite some engines in its fleet that have exceeded, or are approaching these limits. I also expect that Japanese authorities are approaching this from a very conservative side in terms of service time/cycle limits -usually the Japanese (both authorities and airlines) are even more conservative than European and North American parties.

Sulphidation is usually prevented by applying or fine-tuning TBC (Thermal Barrier Coating) characteristics.
Sometimes a small change in operating temperature of the turbine stage can also do the trick. Changing cooling patterns, to have subject stage run a little cooler (or hotter!) might work. One has to take care though that the sulphidation doesn't move upstream / downstream affecting other turbine stages.
Also, introducing and fine-tuning turbine-wash program can also reduce sulphidation problems.

Rgds,
PW100

Revelation · Mon Aug 29, 2016 11:20 am

PW100 wrote:
I read this as a "Sulphidation" problem on one of the turbine stage blades, also referred to as "Hot Corrosion". This is not related to moisture. The corrosion agent is sulphur, which can originate from the environment (particles hanging in the air) and/or jet fuel.

Another important characteristic, is that this "corrosion" process only occurs in a very narrow temperature band, and can be quite difficult to predict how it will develop. Usually it will take thousands of hours and//or cycles (sometimes even 10000+ hrs/cls) to develop, and thus can take quite some service time before showing up.
High-cycle operations iare more vulnerable as they spend more (relatively) time at low altitudes where air pollution (smog) induces sulphidation.

Thanks for sharing your insights. In rereading the quotes from Robert Mann and in context of yours, it seems "moisture in the exhaust" was just being used as a metaphor. The article above said:

Corrosion caused by sulfides could be caused by the “combination of higher temperature stresses in the climb portion” of flight, followed by shorter than typical periods at cruising altitude, he said.

And this is in line with your post. I was not aware of "hot corrosion", it's all new to me.

It seems as you write that there will be some adjustments needed to the operating regime, as well as perhaps some changes to the blade coatings as well.

KarelXWB · Mon Aug 29, 2016 2:31 pm

Article below says 17 of 100 engines have already been fixed.

http://aviationweek.com/commercial-avia ... engine-fix

So far ANA has replaced turbine blades on 17 engines, out of the total of 100 engines on its 50 787-8s and -9s. The carrier says it has “identified that multiple engines need to be serviced.” ANA uses the Rolls-Royce Trent 1000 engines in its 787 fleet.

calt03 · Mon Aug 29, 2016 2:51 pm

Shows that the 787 can operate domestic short hops, but not necessarily in high corrosion environments around seaside airports without maintenance/quality issues.

Revelation · Mon Aug 29, 2016 3:59 pm

calt03 wrote:
Shows that the 787 can operate domestic short hops, but not necessarily in high corrosion environments around seaside airports without maintenance/quality issues.

... up to this point in time (and what does the seashore have to do with a sulfur corrosion problem?).

Clearly these events are building RR's knowledge base about this problem.

PW100 wrote:

Sulphidation is usually prevented by applying or fine-tuning TBC (Thermal Barrier Coating) characteristics.
Sometimes a small change in operating temperature of the turbine stage can also do the trick. Changing cooling patterns, to have subject stage run a little cooler (or hotter!) might work.

We don't know the long-term prognosis for this issue. It could be a 'solved problem' in the relatively near future, who knows?

Stitch · Mon Aug 29, 2016 5:31 pm

calt03 wrote:
Shows that the 787 can operate domestic short hops, but not necessarily in high corrosion environments around seaside airports without maintenance/quality issues.

And yet Japan Airlines, which operates the 787 in the same conditions, is evidently not experiencing this problem. Of course, they have GEnx engines (which admittedly have had their own issues).

So it's a Trent 1000 engine issue, and not a 787 issue. Speaking of JAL, it will be interesting to see if the Trent XWBs on their A350s experience a similar issue, though I imagine RR would be examining those engines, as well.

PW100 · Mon Aug 29, 2016 5:33 pm

Revelation wrote:
We don't know the long-term prognosis for this issue. It could be a 'solved problem' in the relatively near future, who knows?

Sure. Usually short term fixes involve replacing affected parts with the same part number (at considerable discount) that offer another couple of years of service time (until they corrode/time-out as well). That gives the OEM and operator some time to develop and implement a proper fix.

KarelXWB · Mon Aug 29, 2016 5:33 pm

Stitch wrote:
Speaking of JAL, it will be interesting to see if the Trent XWBs on their A350s experience a similar issue, though I imagine RR would be examining those engines, as well.

JAL won't be getting A350s until 2018/2019, any engine issue will be long sorted out by then.

Stitch · Mon Aug 29, 2016 5:41 pm

KarelXWB wrote:
Stitch wrote:
Speaking of JAL, it will be interesting to see if the Trent XWBs on their A350s experience a similar issue, though I imagine RR would be examining those engines, as well.

JAL won't be getting A350s until 2018/2019, any engine issue will be long sorted out by then.

One hopes. And I don't say that as a "Debbie Downer" but based on RR having this issue four years ago with their transfer gearboxes and now experiencing it on their turbine blades. Of course, ANA is the only operator (of significant size) who does short hops with the Trent 1000 so it stands to reason they will be the first - and perhaps only - ones to experience this so RR does not have a large dataset to work from. But again, I imagine RR is already examining the Trent XWB (and Trent 7000) for similar use of materials that have suffered this sulphate corrosion on the Trent 1000 and working to reformulate them, as well, in a proactive manner.

KarelXWB · Mon Aug 29, 2016 5:44 pm

Pretty sure RR will look into the matter on other engines too, though I doubt JAL will mainly use the A350 on short routes.

Stitch · Mon Aug 29, 2016 5:53 pm

KarelXWB wrote:
Pretty sure RR will look into the matter on other engines too, though I doubt JAL will mainly use the A350 on short routes.

Agreed, but I expect we'll see some of those A350-900s go domestic as 777-200 replacements. And they may add more A350-1000s down the road as 777-300 replacements (if not use the ones they have on order in that role to begin with considering their 777-300ER fleet is younger and can hold on longer).

KarelXWB · Tue Aug 30, 2016 11:18 am

ANA says 787 engine repairs could take 3 years:

http://www.reuters.com/article/us-ana-r ... SKCN1150OZ

Japanese carrier ANA Holdings Inc (9202.T) said on Tuesday it could take as long as three years to replace faulty turbine blades in the Rolls-Royce (RR.L) engines powering its Boeing (BA.N) 787s.

"It is an issue but it's a manageable issue," Rolls-Royce Chief Executive Warren East told Reuters after a business forum hosted by the German foreign ministry in Berlin on Tuesday. "With the more intensive use, the natural wear and tear on the engines happens sooner," he said.

KrustyTheKlown · Wed Aug 31, 2016 4:37 am

3 years seems like a long time for ANA to keep operating its 787s in short missions having a high probability of having engine issues. It's true that engine parts have a long lead time, but 3 years seems excessive if they are just going to replace damaged blades.

It seems to me that RR is going to apply a short term fix while they research and certify a long term solution to the problem. What I find troubling is that the same issue may be present in the Trent 7000 (A330neo) that will see an usage similar to ANA's 787s.

dc10lover · Thu Sep 01, 2016 3:18 am

I just read the headline ANA is going to replace all Rolls Royce engines but because of a paywall i could not read the article.

dc10lover · Thu Sep 01, 2016 3:28 am

Couldn' t read the article but will ANA go for General Electric engines?

StTim · Thu Sep 01, 2016 4:53 am

replace engine parts not complete engines. No hint of changing supplier.

frmrCapCadet · Thu Sep 01, 2016 3:31 pm

How much maintenance time is involved with monitoring all of this. Is it fairly simple, require special equipment, is an engine good/bad or more likely in need of more intensive monitoring?

Sooner787 · Thu Sep 01, 2016 3:54 pm

frmrCapCadet wrote:
How much maintenance time is involved with monitoring all of this. Is it fairly simple, require special equipment, is an engine good/bad or more likely in need of more intensive monitoring?

Would it be safe to assume these engine repairs / replacement would be covered by a RR warranty?

KarelXWB · Thu Sep 01, 2016 3:57 pm

I assume maintenance would be covered by RR TotalCare.

wjcandee · Thu Sep 01, 2016 4:18 pm

The idiots at CNN now have a headline: "Entire Dreamliner Fleet Needs New Engines".

Wrong. ANA will replace all its engines, eventually, but for now will replace some turbines, as the CNN article says.

The Rollers are a small percentage of the in-service engines, so the vast majority of the fleet is fine.

The CNN nitwits also say that "The program continues to suffer from teething pains and lackluster sales."

Suffer?

Lackluster sales?????

Morons. So sad that the new generation of reporters doesn't bother to check anything that they write against reality. I assume that Boeing PR will bust them shortly.

neutrino · Thu Sep 01, 2016 4:20 pm

dc10lover wrote:
I just read the headline ANA is going to replace all Rolls Royce engines but because of a paywall i could not read the article.

http://www.channelnewsasia.com/news/bus ... 90598.html

LTC8K6 · Thu Sep 01, 2016 4:23 pm

https://www.ana.co.jp/group/en/pr/787/pdf/20160826.pdf

Although the above measures were in place, the same issue occurred on ANA Flight 609, a domestic flight from Haneda to Miyazaki, on August 20. Therefore, based on our own initiative, we have decided to replace the engines on aircraft used for domestic operations earlier than what was designated by Rolls-Royce. This has led to a temporary reduction in available aircraft, which in turn has led to some flight cancellations.
Going forward, we will be replacing the engines with new ones which are equipped with improved, corrosion-resistant turbine blades as a permanent solution. As a measure to prevent the occurrence of cracks until this solution is fully implemented, engines which have been removed from aircraft will be fitted with brand new or minimally-used turbine blades of the type that is currently in use. We would like to emphasize that this current type of turbine blade does not pose any safety concerns when in brand new or minimally-used condition.

Channex757 · Thu Sep 01, 2016 4:29 pm

I've read some pretty atrocious reporting on this issue today. The facts are:

ANA needs to attend to turbine blades that are suffering corrosion and failure. RR is fully involved and has a replacement ready to go later this year. Part of the NH issue might be related to their higher cycles but that isn't relevant on the ramp today. What is relevant is the issue is being managed by the airline and other RR carriers by increasing inspections and maintenance that RR picks up the tab for under TotalCare.

Only five engines at NH are affected but RR and the airline will modify the entire fleet in due course. The forthcoming Trent 1000-TEN should not even have this issue so all new builds will be perfect out of the crate.

Egerton · Sat Sep 03, 2016 9:59 am

It has been suggested that the corrosion is caused by sulpher, which may be sulphuric acid. Years ago the UK started importing oil from Libia (North Africa). There was trouble because this oil contained a high sulpher content. I guess that vehicle exhaust pipes were corroding at a higher rate than normal. I wonder what the RR specification is for engine fuel? I also wonder why ANA are making such big trouble for RR? In the normal course of events, such turbine blades would be replaced during routine maintenance over a period of many years, as required by the hours flown and flight cycles.
Given that the earliest 787 deliveries were to ANA, some of these engines will have clocked up quite a few hours and cycles, but many will be nearly new. Does this account for the initial rush to replace some high hours/cycles blades, but the quoted 4 years to do them all?

JerseyFlyer · Sat Sep 03, 2016 12:39 pm

[quote="LTC8K6"]https://www.ana.co.jp/group/en/pr/787/pdf/20160826.pdf

From this link to the official ANA account, it is the INTERNATIONAL aircraft that have been worst affected, not the domestic ones. ANA expected that the domestic fleet would not be affected so soon, but a recent case demonstrated otherwise, and it is that unanticipated occurrence upsetting their pre-existing planned maintenance solution that has caused the recent disrupted domestic schedules:

"Compared with aircraft operating on international routes, those which operate on domestic routes within
Japan fly through airspace with lower atmospheric concentrations of the chemical components in
question and their engines also have a lower power output. Therefore, it was determined that fatigue
cracks due to sulfidation corrosion is less likely to occur in such an operating environment and these
engines will not be subject to systematic replacement."

It follows that other operators of RR B787s are likely to be equally affected once they have accumulated similar cycles to ANA's early frames.

Egerton · Sat Sep 03, 2016 4:45 pm

Thanks Jersey Flyer for that. It looks to me then that the causation could be excess sulphur in the fuel, or excess water in the fuel,or a stronger coating is needed for the blades? Alternatively, well I am out of ideas? I suppose in time we will get to know what is really hapenning

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