Boeing 787 engines

[p.j.m]

Houston, do we have a problem?

In the last week 2x ANA 787 engines have failed, one caught fire and one Jetstar one failed causing a diversion to Guam. Any others???

NH609 August 20, 2016
NH959 August 14, 2016
JQ12, August 7, 2016

[Hogger60]

Not clear whether the 20Aug16 NH609 was a failure, or an inflight precautionary shutdown. While the 14Aug16 ANA looked to be a catastrophic engine failure (lots of fire, parts on the runway), the Jetstar engine was shutdown inflight due to low oil pressure.

All 787, but different engine types. The two NH 787's were Trent 1000's, while the Jetstar was a GE.

During that same time frame 3 A320's, 2 330's, 3 737's, 1 777, and 1 A300, and 1 CRJ all shut down engines inflight (failed??). Engine shutdowns happen all the time.

[A4]

True. But the fleet size of 787 is a lot smaller and the number of engine cycles they do will be a lot less compared to a 12 sector a day A320/B737 LoCo.

I'm sure there's a clever statistician out there who could work out the maths/probabilities - it's beyond me.

[TURIN]

Twelve sectors a day!
Really? Who does that?

[Scuffers]

Twelve sectors a day!
Really? Who does that?
is that actually possible?

what's the minimum turn-round time for a 787?

[Hogger60]

quickest I have seen is about 40 minutes if there is no offload/onload of cargo.

True. But the fleet size of 787 is a lot smaller and the number of engine cycles they do will be a lot less compared to a 12 sector a day A320/B737 LoCo.

I don't know if anyone does 12 sectors a day consistently. I would guess 8 or 9 would be more realistic number. And yes, vs. a mature engine such as CFM56, which has been around 25+ years, it is a higher number of shutdowns, but still not a trend (2 different engines) vs. another medium-long haul aircraft such as A330 (2 engine shutdowns in same time frame as the 787 in the initial posting).

[A4]

Twelve sectors a day!
Really? Who does that?

Low cost UK/Europe - EZY and RYR utilise aircraft from 0500 to 0200. Average use is 10-12 sectors a day. They don't make money on the ground. Turn times are 0:25-0:30 mins.

Of more concern is the implications for ETOPS for the 787. Are the ETOPS authorisations unique to to type or type+type of engine? It would seem pretty harsh to pull 787 ETOPS based on say a number of GE shutdowns if your fleet was fitted with Trents. Anyone know?

[tdracer]

Rather than repeat everything, just read this thread:
http://www.pprune.org/rumours-news/582662-jq12-diverts-guam.html

Short answer, 787 IFSD rate (both GE and RR) is quite good, last week was a statistical fluke.

[lomapaseo]

last week was a statistical fluke.

aren't they all :E

[notapilot15]

Most ANA B787 flights are domestic, very few are long haul.

[DaveReidUK]

Average use is 10-12 sectors a day.

EZY's average daily utilisation last year was 11.1 hours per aircraft, and their average stage length was 1 hour 57 minutes, giving an average of 5.69 sectors per day per aircraft.

[Downwind Lander]

The $65,000 question must be: how many such engines are in service now?

[tdracer]

The $65,000 question must be: how many such engines are in service now?
There are over 440 787's currently in service. Engine split is roughly 50-50 between GE and Rolls, although I think GE has a small majority.

[barit1]

notapilot15 Most ANA B787 flights are domestic, very few are long haul.

I covered NH when 747SR's were introduced sometime in a prior millenium. Their average stage flight time was 0:45; the outlier was HND-OKA at 2:00. (I rode a couple 747 legs with 500 paying Pax plus babes in arms!)

[MickG0105]

The $65,000 question must be: how many such engines are in service now?
The B787 fleet is not small by any accepted measure; over 440 in service. Neither is the General Electric GEnx engine pool small; there are well over 1,000 GEnx engines currently in service around the world (it's one of the fastest selling airplane engines of all time) and it has accumulated around 7 million operating hours.
The inflight shut-down (IFSD) requirement for engines under 330 minutes Extended-range Twin-engine Operational Performance Standards is 0.01 IFSDs per 1000 engine hours, which is the same as 10 shutdowns per million hours. To be clear, that means, on the average, one inflight engine shut-down every 100,000 engine hours. The General Electric GEnx engine exceeds that reliability requirement by more than a factor of three. Its reliability is at or about on a par with more "mature" engines such as the CFM CF6-80C2 (Airbus A300, Airbus A310, Boeing B767), the General Electric GE90 (Boeing B777) and the Pratt and Whitney PW4000 (Airbus A300, Airbus A310, Boeing B747).

[A4]

David

That's just a mathematical average - never managed .69 of a sector - hope I never do :eek: I can assure you that the aircraft regularly do to 2 lots of 4 sectors. Domestics may be 6 sectors in one FDP.

My point is that the LoCo fleet engines do a lot more start/stop/take-off/Rev cycles than long haul. With the global fleet of LoCo A320/B737's perhaps 5 or 6 times that of the 787, the statistics start to look "interesting".

Of course we're not comparing like with like. It can be spun however you like such is the way with stats.

[Turbine D]

I think that for the GEnx-1B engine, a couple of fan related problems related to ice shedding and fan imbalance caused shutdowns. This problem was solved by having the engine power increased to 85% N1 periodically when cruising in potential icing conditions with N1 below 85%. Also, a PIP version of the engine produced for certain airlines closed down the fan blade to fan casing clearance, improving SFC. However, that resulted in ice shedding causing fan blade damage and the clearances had to be increased.

[DaveReidUK]

That's just a mathematical average

Sorry, the only way I know how to calculate averages is mathematically. :O

Figures come from EZY's Annual Report.

Average use is 10-12 sectors a day.

Doubtless some of the fleet average that, some of the time ...

[NDBDME]

Royal Brunei has had two Trents 1000Ae fail and a few replaced according to a mate of mine who works there

[jolihokistix]

According to TBS, ANA will be changing all 50 of their RR Trent engines for the 787, and flight cancellations have started from today. The fan blades develop cracks under a build-up of dirt. This news is being suppressed as we speak, apparently. (JAL has GE engines, so they are not affected, the news source says.)

The content of the main report on TBS (in Japanese) has now disappeared but the earlier one about the series of engine failures with ANA and the need for replacement parts is here: ??? ???????????????????????????News i - TBS?????????? (http://news.tbs.co.jp/newseye/tbs_newseye2853692.html)
??? ???????????????????????????News i - TBS?????????? (http://news.tbs.co.jp/newseye/tbs_newseye2853692.html)

[crippen]

Japan's ANA cancels Dreamliner flights over engine trouble
25 Aug 2016 at 18:45 2,011 viewed0 comments
WRITER: AFP
TOKYO - Japan's All Nippon Airways said Thursday it is cancelling some Boeing Dreamliner flights owing to a problem with the plane's engine, and warned of more groundings.


ANA has grounded a Boeing Dreamliner flight and is cancelling some others, citing engine problems.
The carrier, the biggest worldwide Dreamliner operator with a fleet of 50 jets, said nine domestic flights scheduled for Friday would be halted so it could fix a problem with a Rolls Royce-produced engine.

The move came after ANA grounded a domestic Dreamliner flight earlier Thursday, also citing an unspecified engine problems.

"We will definitely cancel nine flights tomorrow and more afterward but we don't know the specifics yet," an ANA spokeswoman said.

Japan's ANA cancels Dreamliner flights over engine trouble | Bangkok Post: business (http://www.bangkokpost.com/business/world/1070736/japans-ana-cancels-dreamliner-flights-over-engine-trouble)

[notapilot15]

RR must be really busy sending legal teams, NDA reminders and C&Ds.

[CONSO]

Boeing 787 engine trouble prompts ANA to cancel some flights

Originally published August 25, 2016 at 10:39 am Updated August 25, 2016 at 2:31 pm

Boeing 787 engine trouble prompts ANA to cancel some flights | The Seattle Times (http://www.seattletimes.com/business/boeing-aerospace/787-engine-trouble-prompts-ana-to-cancel-some-flights/)

All Nippon Airways (ANA), the world’s biggest operator of Boeing 787 Dreamliner jets, announced Thursday in Tokyo it is canceling nine domestic flights on Friday because of a corrosion problem with the plane’s engines.
Takeo Kikuchi, a deputy senior vice president of engineering and maintenance at ANA, told reporters Thursday in Tokyo the airline may have to scrap more than 300 Dreamliner flights through the end of September as it moves to replace parts inside the engines on a portion of its 787 fleet.
The airline’s fleet of 50 787s are all powered by Rolls-Royce engines.


About 38 percent of all the 787s in service are powered by those engines, while the rest are outfitted with General Electric engines. . . .


GOES ON

[Turbine D]

The apparent problem is hot corrosion caused by sulfur.

Sulfur in the fuel and airborne salts like sodium and chlorine reacts with the oxide layer on the blades in the high temperature environment of the turbine to attack the base metal of the blades. As a normal by-product of combustion, sulfur oxides are formed that combine with the salts and other elements ingested into the engine. This reaction forms sodium sulfates that expose the blade's protective oxide layer to decay. Water is also produced as a by-product of hydrocarbon fuel combustion, and this water can combine with the sodium sulfur compounds to produce sulfuric acid.

Usually, the attack is worse in the blade shank or tip shroud areas and the actual gas path airfoil area looks pretty good. Because of this, blades have to be removed from the rotor disk to determine if cracks are present. And that is what ANA will do on all their RR engines. There are coatings that can be applied to mitigate hot corrosion. All jet engines including turboprop engines can have this problem to a degree.

[safetypee]

Turb D, would the corrosion depend on the properties of the fuel? E.g. Anti fungal, anti ice additives.

Are these occurrences focused on certain operators or world regions? E.g. Relatively high atmospheric sulphur content in volcanic areas.

[tdracer]

Safetypee
Short answer is all of the above - sulfur in the fuel, sulfur in the air, air pollution can all contribute. Plus, ANA was the first operator for the 787 and has the largest fleet to date (50 aircraft). So they tend to be the first to see longer term problems.

[notapilot15]

Is this issue unique to Trent 1000 or other RR engines have similar issues?

[tdracer]

I don't have any specific knowledge about the ANA issue (I don't work Trent and I don't work 787). But as Turbine D noted, all gas turbine issues are susceptible to hot section corrosion due to sulfur and other contaminants in the fuel and air - it's just a matter of degree. There are coatings that are used on the turbine blades to prevent corrosion - some work better than others.
Educated guess here, but I suspect ANA had a turbine blade failure or a borescope finding. When the looked into it they discovered a widespread problem had developed and they needed to take prompt corrective action.

[Turbine D]

safetypee,

There are two types of jet fuel used, Jet A and Jet A-1 in the Western world. Jet A-1 is used in Japan primarily because of its lowered freezing point compared to Jet A and the fact of many long distance routes flown including polar routes. The US uses primarily Jet A because more fuel is produce using the same amount of petroleum as a starting point, and therefore it is less expensive. Jet A-1 mandates an antioxidant be used and a static dissipator additive for safety reasons. Jet A requires no additives, but both jet fuels can have additional additives by agreement and approvals of authorities and engine manufacturers. Biocides and icing inhibitors are commonly added to both jet fuels. As I recall, additives are extensively tested at 4 times the maximum amount to assure no damage to engine components occurs. In fact biocides are beneficial in that they breakdown fungus and other microorganisms that produce acids when burned at high temperatures. So I think additives are pretty safe.

notapilot,

I would agree with tdracer's explanation.

[CONSO]

Very early in the 7x7 ( later to be 787 ) program- somerelatively young and MDC management was pushing for a single engine manufacturer- to save costs, etc. Several old timers pushed back and eventually won the day by insisting that more than one be selected from the 3 majors, AND that a standard ' pylon' and attachment scheme be imposed- sort of a ' plug and play ' concept.

The otheer ' selling ' point for more than one was the reduction of risk and less chance of a delay due to engines. Of course as it turned out- the engine risk was not the issue resulting in many many months delay. :8

[Una Due Tfc]

I see ANA had another Trent 1000 fail yesterday. Must be a fun situation for the crews...

[p.j.m]

I see ANA had another Trent 1000 fail yesterday. Must be a fun situation for the crews...

NH241 August 26, 2016
NH609 August 20, 2016
NH959 August 14, 2016

This doesnt look good, seems ANA are taking no chances after the spate of their B787 engine failures...

https://www.ana.co.jp/apps/info/info20160826145351633.pdf

Apology Domestic flights cancellation and delay due to Boeing 787 maintenance

This information is valid as of 3.00 pm August 26, 2016

The safety of our passengers is our highest priority. ANA has decided to conduct inspection and
maintenance work on the engines of a limited number of Boeing 787 aircraft.

Due to this maintenance work, some flights on ANAs domestic routes will be cancelled or delayed
on and after Friday, August 26. Details of the cancelled flights, delayed flights and information for
passengers with reservations on these flights are as follows. Flights on the international routes will
not be affected.

We offer our deepest apologies for the concern and inconvenience caused to the passengers with
reservations on these flights, and everyone who may be affected.

1. Cancelled and Delayed Flights

Friday, August 26

(1) Cancelled Flights

Tokyo (Haneda) Osaka (Itami)
ANA15 08:00 09:10
ANA39 19:00 20:15

Osaka (Itami) Tokyo (Haneda)
ANA20 10:00 11:15

Tokyo (Haneda) Fukuoka
ANA255 13:25 15:15
ANA265 17:00 18:50

Fukuoka Tokyo (Haneda)
ANA260 16:10 17:55
ANA270 19:40 21:25

Tokyo (Haneda) Hiroshima
ANA683 16:55 18:15

Hiroshima Tokyo (Haneda)
ANA686 19:00 20:25

(2) Delayed Flights (Over 20 minutes)

No delayed Flights

Saturday, August 27
(1) Cancelled Flights
Tokyo (Haneda) Osaka (Itami)
ANA25 13:00 14:05

Osaka (Itami) Tokyo (Haneda)
ANA16 08:00 09:15
ANA30 15:00 16:15

(2) Delayed Flights (Over 20 minutes)
Tokyo (Haneda) Yamaguchi
ANA693 10:20 11:55
11:30 13:05

Yamaguchi Ube Tokyo (Haneda)
ANA696 12:40 14:20
13:45 15:25

Sunday, August 28

(1) Cancelled Flights
Tokyo (Haneda) Osaka (Itami)
ANA25 13:00 14:05

Osaka (Itami) Tokyo (Haneda)
ANA30 15:00 16:15

Tokyo (Haneda) Hiroshima
Fight No.
Dep. Tokyo Arr. Hiroshima
ANA683 16:55 18:15

Hiroshima Tokyo (Haneda)
ANA686 19:00 20:25

(2) Delayed Flights (Over 20 minutes)

No delayed Flights

Monday, August 29
There will be no flight cancellation or delays.

Tuesday, August 30
There will be no flight cancellation or delays.

Wednesday, August 31

(1) Cancelled Flights

Tokyo (Haneda) Fukuoka
ANA261 15:45 17:35

Fukuoka Tokyo (Haneda)
ANA260 18:35 20:20

2) Delayed Flights (Over 20 minutes)

Tokyo (Haneda) Kumamoto
ANA645 14:50 16:30
15:10 16:50

Kumamoto Tokyo (Haneda)
ANA648 17:15 19:00
19:20 17:35

Details of the affected flights in September will be posted on this website on or after Monday, August 29 once finalized.

2. To passengers with reservation on the affected flights.
Please see the details from the link below for to change flights or refund if your reserved flight
has been cancelled.

Involuntary Changes due to ANA's responsibilities such as aircraft maintenance (Transfers to a Flight Operated by Another Airline)?Book Flights/Plan Travel [Domestic]?Flight Reservations?ANA (http://www.ana.co.jp/wws/japan/e/local/book-plan/refund/domestic/aircraft/transfer-other.html)
August 26, 2016

All Nippon Airways Co., Ltd.

[notapilot15]

Amazing what heat, liquids and gases can do even to titanium.

[Turbine D]

notapilot,

The turbine blades would not be made of titanium, they would be a nickel-base superalloy.

[Annex14]

Hello D,

sounds a bit like "intergranular corrosion" ? doesn´t it ??

[safetypee]

tracer, Turbine D, thanks for those points; one more question.
Is it likely that engine variants or build standards will have different blade coatings?

Comment: ... additives extensively tested ... additives are pretty safe ...
The sceptic in me recalls something similar being said about Type 4 de-icing fluids!!!!

Wild thought:
Was ANA one of those operators who were affected by ice crystal problems (GE engines though??). Would an operator be inclined to emphasise icing additives (by adding more), even though unrelated and unnecessary?

[Turbine D]

Annex,
In a way, intergranular corrosion is a good description, but the mechanisms to reach that point can be different.

One way is surface oxidation that develops cracks in the oxide layer that then spreads to the base alloy. The growth of grain boundary cracks in the base alloy is generally accelerated by composition changes.

Another way is sulfidation (hot corrosion) of which there are two types depending on the temperature being experienced. Here the base alloy is attacked by the sulphur compounds which results in loss of alloy and pitting where the nickel in the alloy is consumed. The sulfur compounds continue down the grain boundaries where it depletes the chromium, leading to development of cracks.

[Turbine D]

safetypee,

I don't think ANA has any of the GE engines designed for the 787s.

Each engine manufacturer has proprietary in house turbine blade coatings and processes or may use patented coatings from a coating supplier that applies the coating.

All I can say about the fuel additives is they are approved (or not) by multiple authorities worldwide besides the engine manufacturers.

[lomapaseo]

The coatings work when the process for applying them is followed to the spec.

If a batch traceable to a supplier and time period shows up in the failure/findings, go after the process and not the coating.

[notapilot15]

Thanks Turbine D for the clarification, with all the publicity about titanium/CFRP fan blades, didn't know/assume that blades in most stages still have alloys. Is it a cost saving measure or steel alloys are better suited?

Do airlines boroscope engines as part of regular mx, if so how frequently.

Also, is there any other Trent(not just 1000) operator with such short flight lengths, or ANA's situation is unique.

[aeromech3]

My experience, from the mid 1970's, when I started boroscope inspections of JT8D engines, the issue was sulphidisation, the Operator was in the Arabian Gulf where the fuels uplifted had a higher sulphur content and lower lubricosity also causing premature failures in their RB211 fuel contol units. For the JT8D regular water wash was introduced. By chance they also leased ANA L1011's and had serious trouble with their RB211 engines. For the FCU's modified bearing materials helped; as these 787 seem to mostly operate within Japan local fuel might be a contributing factor.

[tdracer]

Do airlines boroscope engines as part of regular mx, if so how frequently.
Yes, engine boroscope is a scheduled maintenance item - frequency depends on the engine and where in the engine (hot section is more frequent), typically cycle based. When there are known issues the interval is often shortened - often if there is a finding, they are allowed to continue operation but need to re-check at a very short interval (I've seen as little as 10 cycles) to make sure it's not getting worse. Obviously at some point the problem will drive the engine off-wing.

[notapilot15]

Thanks tdracer. So this must be a known phenomenon with narrow body engines with higher cycle rate and should be a easy fix.

BTW, cynic in me still thinks even a good engine goes bad as soon as it is hung on jinxed 787. Honeywell sold thousand+ of same ELTs, on a B787, it went up in flames.

aeromech3

I heard another operator needed early overhaul of their CFM56s, apparently they were failing prematurely by flying to ME. Is this something to do with sand??

[aeromech3]

To notapilot15, the silica from sand deposits in the engine, in the hot section it forms what is commonly known as glass, this is not a problem when molten but on engine shut down / cool down, it solidifies and causes the most problem on the T1 blades where it blocks the cooling holes; on engine start when max temperature is critical, the blades have reduced cooling and suffer extra thermal stress, hence life shortening, especially when this occurs on more times on short cycle operation. One has to remember the Operator of short cycle flights has a modified maintenance schedule which should capture this accelerated degredation by more emphasis on cyclic life. As stated earlier ANA are fleet leaders and 1st to experience such unpredicted events.

[Chu Chu]

I wonder if the recent (very low) sulfur standards for automotive diesel might be pushing more high-sulfur crude into jet fuel production. (I doubt any crude can meet the new diesel standards without additional processing, but it seems reasonable that it would be easier if you had less sulfur to start with.)

[barit1]

notapilot15:I heard another operator needed early overhaul of their CFM56s, apparently they were failing prematurely by flying to ME. Is this something to do with sand??

Not unique to any particular engine type. Helos (turboshaft) operating in Vietnam suffered much distress due to sand & dust - airfoil erosion esp. in the compressor, and blocked cooling passages in turbine airfoils.

My own experience in the ME saw small compressor airfoils worn so badly, the sharp-cornered leading & trailing edge corners resembled the semielliptical wingtip of the Spitfire!

[Pinkman]

I wonder if the recent (very low) sulfur standards for automotive diesel might be pushing more high-sulfur crude into jet fuel production. (I doubt any crude can meet the new diesel standards without additional processing, but it seems reasonable that it would be easier if you had less sulfur to start with.)

Actually you have the right effect but the reason is different. Typically, Jet (whether Jet A or Jet A-1) is sold to a spec and the parameters are strictly controlled. In the case of Sulfur/Sulphur (S) the spec is, in theory, independent of the source crude, its just that the refinery will need to carry out additional processing (e.g. by hydrotreating) if the source crude is high in S. Its not just elemental S either - it is active S compounds such as mercaptans and the spec has come down over the years, which is why you have seen many "Jet Merox" plants bolted on to Refineries in the ME for example over the last 20 - 30 years to reduce these S species. High levels of active S compounds like mercaptans cause the fuel to fail the "Doctor Test" and are bad news in Jet.

The problem has been that as road fuel S specs have tightened, hydrotreating has become oriented to the biggest cut (diesel and catalytically cracked gasoline) where mercaptans are less critical. As more gasoline selective hydrotreating units are placed on stream, the levels of mercaptans in the higher fractions like Jet have been rising. But the spec willl still have been met, probably through additional after-treatment.

We continually see specs tightening in response to better engine technologies (and even environmental initiatives eg from ICAO) as well as problems like the introductions of road biofuels which caused the bleed of biodiesel or "FAME" from multi product pipelines into Jet. You need to be a bit careful of characterising S as "the enemy" however. S does provide lubricity for injectors and the New Zealand case where ultra-low S Jet caused serious problems in the domestic fleet (not L/haul which only filled up in NZ on departure) is instructive.

[lasernigel]

The turbine blades would not be made of titanium, they would be a nickel-base superalloy.

Worked for a company that used a laser to harden the 1000 blades. I can assure you that they are titanium.

[Una Due Tfc]

Worked for a company that used a laser to harden the 1000 blades. I can assure you that they are titanium.

Depends on which stage you're talking about. The further back you go, the higher the temps.

[lasernigel]

Depends on which stage you're talking about. The further back you go, the higher the temps.

Main fan blades

[p.j.m]

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

https://i.imgur.com/qRhY7Qe.jpg

[Turbine D]

lasernigel,
Look at the engine cross-section in the ANA letter provided by p.j.m. I guarantee you the turbine blade in question isn't titanium. If it were, it wouldn't be there for long as it would have melted very quickly.

[nephilim]

Main fan blades


Fan blades are part of the compressor (in front of combustor, i.e., relatively cold) whereas the turbine follows behind the combustor (pretty hot).

[Whinging Tinny]

Depends on which stage you're talking about. The further back you go, the higher the temps. Turbine blades get cooler the further back you go, compressor blades hotter.

The turbine blades are made from single crystal nickel super alloy.

[p.j.m]

An ANA All Nippon Airways Boeing 787-800, registration JA814A performing flight NH-829 from Tokyo Narita (Japan) to Mumbai (India) with 68 people on board, was enroute at FL340 about 150nm westsouthwest of Tokyo about 30 minutes into the flight when the crew decided to return to Tokyo's Narita Airport reporting vibrations of the left hand engine (Trent 1000). The aircraft landed safely on Narita's runway 34R about 85 minutes after departure.

Incident: ANA B788 near Tokyo on Aug 30th 2016, engine vibrations (http://avherald.com/h?article=49d502c4)

[lasernigel]

lasernigel,
Look at the engine cross-section in the ANA letter provided by p.j.m. I guarantee you the turbine blade in question isn't titanium. If it were, it wouldn't be there for long as it would have melted very quickly.

I did state in my second post the "Main fan blades".

[rotornut]

ANA to replace 100 engines on its Boeing 787 Dreamliners - Sep. 1, 2016 (http://money.cnn.com/2016/09/01/news/boeing-787-dreamliner-ana-engine-replacement/index.html)

[megan]

Japanese airline group All Nippon Airways (ANA) has confirmed it will replace turbine blades on the Rolls-Royce Trent 1000 engines powering its fleet of 50 787 aircraft after identifying problems related to corrosion and cracking.

The carrier confirmed on Wednesday (August 31) to Reuters that the process for fitting the 787s with engines equipped with new blades could take up to three years to complete.

ANA said just five of the engines are in need of repairs at present, but it decided to repair the entire fleet of 100 Trent 1000s as a safety measure.

It follows three engine failures in 2016 related to the blades, while 18 domestic flights were cancelled by ANA last week as a result of engine issues.

Air New Zealand, another carrier operating Trent 1000-powered 787s, said it has put “proactive systems” in place across its fleet of seven of the aircraft to any potential monitor turbine problems.

ANA To Replace Engine Turbine Blades On 787s | MRO Network (http://mro-network.com/news/2016/09/ana-replace-engine-turbine-blades-787s/14691?dm_i=2H5E,UK7G,6398E7,291NZ,1)

[TURIN]

It is disturbing.......that one or two posters don't know the difference between Fan, Compressor & Turbine blades.

[barit1]

50 twin-engine 787's - One hundred installed T1000's. If retrofit is needed, it will also no doubt include spare engines. Any Idea how many spares?

[lomapaseo]

50 twin-engine 787's - One hundred installed T1000's. If retrofit is needed, it will also no doubt include spare engines. Any Idea how many spares?

I presume that it's OK to fly if no more than one engine per flight is at high risk

If a couple come off every day and a spare goes on per aircraft it doesn't seem like any more spares than usual are needed.

In the end the risk analysis should ensure that its extremely unlikely that more than one engine loses power or has to be shut down in the life of the retrofit program.

On the other hand if one becomes too aggressive in swapping out engines like two at a time. human error becomes a more significant risk

[notapilot15]

Based on ANA statements initial problem was noticed in long haul fleet, later found in short haul fleet. This contradicts initial reports claiming ANA high-cycle short haul was unique. What about other Trent 1000 operators.

RR fanboys are not happy with ANA demanding RR to fix all engines, same fanboys who quickly claimed GE was the reason for BA276@LAS.

[DaveReidUK]

Who or what are "RR fanboys" ? Are they to be found in Thailand ?

[Warm Ballast]

Investigation: AO-2016-114 - Engine smoke involving Boeing 787, 9V-OFG, Melbourne Airport, Victoria, on 8 September 2016 (http://www.atsb.gov.au/publications/investigation_reports/2016/aair/ao-2016-114/)

[lasernigel]

It is disturbing.......that one or two posters don't know the difference between Fan, Compressor & Turbine blades.

The guys from Barnoldswick always referred to the ones we treated as the main fan blades.
Did 500's, 700's and 1000's. Plus discs for the BR710 series. A lot of it has transferred to Singapore now.

[Turbine D]

lasernigel,

Let's get the terminology correct. This thread isn't about fan blades, it is about an intermediate turbine blade that is apparently problem on the Trent 1000 as experienced by ANA.
Fan blades are in the very front of the engine and run cool. Turbine blades are towards the rear of the engine, aft of the combustor and run hot. Fan blades, some early stages of the compressor (low pressure) and some discs in the fan or early stages of the compressor may very well be made of titanium. In the turbine, there are no titanium blades, vanes or turbine discs because of the high temperatures being experienced. There may be titanium aluminide turbine blades in the very last stage of a five or six stage low pressure turbine of certain engines dependent on temperatures being experienced, but that is only because titanium aluminide has somewhat improved high temperature capability verses common titanium alloys.

Main fan blades are not intermediate turbine blades.

[barit1]

lasernigel:Worked for a company that used a l@ser to harden the 1000 blades. I can assure you that they are titanium.

Could you share with us the approximate dimensions of these blades?

[Longtimer]

Seems to be some disagreement re the engine components. This may help: How jet engine is made - material, manufacture, history, used, parts, components, dimensions, product, industry (http://www.madehow.com/Volume-1/Jet-Engine.html) and http://www.azom.com/article.aspx?ArticleID=11454

[barit1]

Wow. Ugh. The How Products Are Made (http://www.madehow.com) article has several factual and historical errors that need to be addressed. I've seen better stuff in Popular Science.

I didn't even get as far as the manufacturing processes; i hope this section is more accurate & up-to-date.

[lomapaseo]

Well after reading the linked explanations above it would seem that you can't even trust the internet to know the differences between fan, compressor and turbine blade materials or manufacturing.

Now back to the thread subject. Suffice it to say that the Subject engine problems are turbine blades which are quite different in design, manufacturing, operation and repair from the blades in fans or compressors.

[p.j.m]

Advanced Metal Alloys and Their Applications in Jet Engines (http://www.azom.com/article.aspx?ArticleID=11454)

got to the "intricate feet of engineering" in the second sentence of that article and knew the rest wasn't worth reading!

[DaveReidUK]

got to the "intricate feet of engineering" in the second sentence of that article and knew the rest wasn't worth reading!

Pity, apart from that one unfortunate typo/spellcheck fail the rest of the article is actually a pretty reasonable rundown on what materials are used in which parts of a turbofan.

As one might expect from a publication that specialises in Materials Science, in fact.

[lomapaseo]

Pity, apart from that one unfortunate typo/spellcheck fail the rest of the article is actually a pretty reasonable rundown on what materials are used in which parts of a turbofan.

They did fine with materials, but not the where they are used part, which seems to have misled some folks in this thread :)

I've yet to hear of a common usage of the "lost wax" process in compressor blades

[Turbine D]

They did fine with materials, but not the where they are used part, which seems to have misled some folks in this thread
Except for the aluminum compressor blades which I am unaware of. I don't think they would fare well in a sandy environment due to erosion. Also, investment casting, aka, lost wax process, is not used for compressor blades for good reasons. Compressor blades are forged for mechanical property reasons, fatigue strength, grain control, etc., beyond what the investment casting process can produce.

Turbine blades are investment cast because of the high temperature materials now required. In the olden days, turbine blades were forged, but the forged alloys didn't have the higher temperature or the internal air-cooling sophistication capabilities that investment cast turbine blades can provide made with ceramic cores, forming the intricate internal cooling passages. Investment cast turbine blades can be produced with random equiax grain control, directionally solidified grain control or as a single crystal where the entire turbine blade contains no grain boundaries.

Fan blades have been made for many years using titanium alloys and forging processes. Today fan blades on newer engines are being produced using composite materials to reduce weight, improve strength and improve resistance to foreign object damage (bird strike, etc.).

Hope this information is helpful as the articles referenced left quite a bit to be desired and are misleading in some instances.

[DType]

The challenge for forging turbine blades (in the old days) and turbine discs, is that the materials used are the ultimate available in resisting deformation at high temperature. Sort of Catch 22!