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Boeing 787 engines
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 |
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. |
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. |
Twelve sectors a day!
Really? Who does that? |
Originally Posted by TURIN
(Post 9481737)
Twelve sectors a day!
Really? Who does that? what's the minimum turn-round time for a 787? |
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. |
Twelve sectors a day! Really? Who does that? 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? |
Rather than repeat everything, just read this thread:
http://www.pprune.org/rumours-news/5...erts-guam.html Short answer, 787 IFSD rate (both GE and RR) is quite good, last week was a statistical fluke. |
last week was a statistical fluke. |
Most ANA B787 flights are domestic, very few are long haul.
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Originally Posted by A4
(Post 9481912)
Average use is 10-12 sectors a day.
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The $65,000 question must be: how many such engines are in service now?
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The $65,000 question must be: how many such engines are in service now? |
notapilot15
Most ANA B787 flights are domestic, very few are long haul. |
Originally Posted by Downwind Lander
(Post 9482209)
The $65,000 question must be: how many such engines are in service now?
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). |
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. |
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.
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Originally Posted by A4
(Post 9482808)
That's just a mathematical average
Figures come from EZY's Annual Report.
Originally Posted by A4
(Post 9481912)
Average use is 10-12 sectors a day.
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Royal Brunei has had two Trents 1000Ae fail and a few replaced according to a mate of mine who works there
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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?????????? ??? ???????????????????????????News i - TBS?????????? |
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 |
RR must be really busy sending legal teams, NDA reminders and C&Ds.
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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 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 |
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. |
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. |
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. |
Is this issue unique to Trent 1000 or other RR engines have similar issues?
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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. |
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. |
Historical note on 787 Engines
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 |
I see ANA had another Trent 1000 fail yesterday. Must be a fun situation for the crews...
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Originally Posted by Una Due Tfc
(Post 9487115)
I see ANA had another Trent 1000 fail yesterday. Must be a fun situation for the crews...
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/info...6145351633.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 August 26, 2016 All Nippon Airways Co., Ltd. |
Amazing what heat, liquids and gases can do even to titanium.
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notapilot,
The turbine blades would not be made of titanium, they would be a nickel-base superalloy. |
Hello D,
sounds a bit like "intergranular corrosion" ? doesn´t it ?? |
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? |
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. |
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. |
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. |
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. |
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