WARNING: Due to the last thread going off topic quickly and turning into a 'battle ground', the moderators will be watching this thread frequently and ANY offending/rule breaking posts will be removed. Please respect each others right to have their opinion.
Batteries were often switched before the recent issues were acknowledged, some electricity powerback issues were to blame:
Quote: All 10 replacements occurred last year—two in May, four in October, two on one day in November and two in December—involving seven Dreamliners, she said. The airline operates 17 of the planes.
ANA had not reported the replacements to the Japan Transport Safety Board (JTSB) because “the 10 problems were found before flights so were considered not to affect safety”, Yamamoto said.
A JAL spokeswoman said the company had experienced “quite a few cases” where Boeing 787 batteries had to be replaced before the aircraft was grounded worldwide. She added that no further details were immediately available.
sweair From Sweden, joined Nov 2011, 1758 posts, RR: 0 Reply 3, posted (10 months 3 days 10 hours ago) and read 30502 times:
What if this comes down to bad batteries of later batches? Have they changed the chemistry since EIS? Shorts in the battery they say, does that not point to a manufactoring glitch? They will need to beef up the containment, is that a long certification?
The cells that shorted, they must be identfied for root cause and fixed at the factory?! But if they find the "smoking gun" what happens next?
NAV20 From Australia, joined Nov 2003, 9742 posts, RR: 37 Reply 5, posted (10 months 3 days 6 hours ago) and read 29972 times:
Quoting sweair (Reply 3): What if this comes down to bad batteries of later batches? Have they changed the chemistry since EIS? Shorts in the battery they say, does that not point to a manufactoring glitch?
Apparently a higher-than-normal proportion of batteries have required replacement since the 787 entered service - but none of the previous incidents have caused any danger. As far as a 'trend' can be established, the previous incidents have involved the batteries becoming fully discharged (mostly, apparently, due to incorrect disconnection/discharges while the aeroplanes were on the ground), at which point safety cut-offs operated and the batteries had to be exchanged.
So while Boeing will obviously have exhaustively to check the batteries themselves, it looks as if they will also have to check the rest of the aeroplane's power systems - especially the recharging processes.
For information, the batteries, as we know, are produced by GS Yuasa in Japan. The firm in general charge of the design of the 787's electrical systems is the French company, Thales. The recharging system was designed by a firm called Securaplane, based in Tucson, Arizona - they were a US firm when they joined the 787 programme, but they have since been taken over by a British company, Meggitt PLC.
So it looks as if a truly international effort will be needed to sort this business out.......
Quoting Speedbird128 (Reply 2): I trust that this single test flight is not going to be a basis for a thumbs up to lift the grounding....???
No chance at all of that, Speedbird128. I imagine that test flights will continue nonstop for quite a while.
[Edited 2013-02-10 04:46:41]
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
Speedbird128 From Pitcairn Islands, joined Oct 2003, 1453 posts, RR: 2 Reply 6, posted (10 months 3 days 5 hours ago) and read 29884 times:
Quoting NAV20 (Reply 5): No chance at all of that, Speedbird128. I imagine that test flights will continue nonstop for quite a while.
I would also imagine so... it just sounded that 1 positive test flight and it was looking good. That in itself is great, but 99.9% of flights had no battery thermal runaways either... so it was just my inquisiviteness at the wording of the report.
Quoting NAV20 (Reply 5): So it looks as if a truly international effort will be needed to sort this business out
Thats what the 787 is (and most major other engineering projects as well) - a major international effort.
NAV20 From Australia, joined Nov 2003, 9742 posts, RR: 37 Reply 8, posted (10 months 3 days 4 hours ago) and read 29658 times:
Quoting Aesma (Reply 7): I don't think that's true. At least when we were talking about the ZA002 incident, it was Zodiac that was involved. Another French company.
Looks like they're both involved, Aesma? I've no idea to what extent the situation affects each individual company:-
"Les malheurs du 787 pourraient avoir de sérieuses conséquences pour les équipementiers aéronautiques français. De tous les Boeing, cet avion est celui sur lequel la part d'équipements français est la plus importante, si l'on exclut les moteurs CFM du 737. Safran, Thales et Zodiac vendent chacun pour plusieurs millions de dollars d'équipements par appareil. Tout problème technique qui ralentirait le rythme de production et de livraison du « dreamliner » serait autant de chiffre d'affaires en moins pour eux."
Revelation From United States of America, joined Feb 2005, 11420 posts, RR: 24 Reply 11, posted (10 months 3 days 2 hours ago) and read 29121 times:
I agree with the thread starter, let's talk ideas/opinions/issues and leave any comments about fellow posters out of this.
What I was going to post to the other thread is that I agree that the 787 won't return to service till the root cause is found and eliminated. I think it's likely that the airlines themselves if not other international agencies would reject any workaround based scheme that doesn't conclusively eliminate the root cause. From what has been made public we know short circuits appear in individual cells of the Li-Ion battery but we we haven't been told the cause of the short circuit. It seem the test flights are geared towards determining if the cells flex during flight and cause the short circuit.
It's a real ugly situation for Boeing. Changing the battery technology then requires changes to the upstream charger and monitoring tech. Not changing the battery technology means they have the burden of proving the relatively new tech is safe after the highly public failures.
It seems this is one of those times that CEOs are supposed to be earning their ridiculously high salaries (something like 400 times the average worker's wage in the US). Time to see if McNearney et al can save the day!
2175301 From United States of America, joined May 2007, 1022 posts, RR: 0 Reply 12, posted (10 months 3 days 1 hour ago) and read 28885 times:
I would disagree that the root cause has to be eliminated. It has to be understood; and contained from causing significant flight or safety issues.
It is also possible that they may never find a leading Root Cause. Sometimes all you do in these investigations is identify things that need improvement; even if you cannot conclude that one (or two) of them are the Root Cause.
I would also agree that the batteries on the test flights are heavily instrumented with all kinds of extra sensors. For example mounting stress/strain gauges on the connecting bus bars and individual terminal posts seems rather obvious. I do believe that it is likely that the flexibility of the cells and the rigidity of the connecting bus bars are causing unanticipated flexing in the cells near the terminal post. That kind of problem occurs in all kinds of industries. Usually the answer is to provide more flexibility as you can rarely make the rest of the system ridged enough.
My personal guess at the solution for these batteries is:
1) The basic cell is reused as is.
2) Ridged connecting bars between the cells are replaced by flexible cables
3) To prevent a run-away cell from overheating the next cell about a 1/16" - 1/8" layer of insulating ceramic (likely the same material as the Space Shuttle Tiles as it is readily available) will be placed between the cells.
4) The containment box will become more robust.
5) They may include better temperature monitoring of the individual cells; which will require software changes in at least the monitoring and data storage software (I doubt this warrants any changes to information presented to the flight deck).
DTW2HYD From United States of America, joined Jan 2013, 924 posts, RR: 2 Reply 13, posted (10 months 2 days 22 hours ago) and read 27139 times:
Would large number of smaller cells helped with thermal runaway issue. I was reading Telsa Roadster's battery system paper. It has 6800 small cells vs 8 large cells on B787. Likelyhood of a car battery pack getting damaged is very high, but not many lives at risk. Tesla's theorey is 6800 x approx AA size batteries create large surface area to dissipate heat optimally.
I know someone who is high level in UTC Aerospace Systems (the company Goodrich is now a part of) and he has said they did tests on the electrical system they provided and found it has nothing to do with the issues. It all leads back to the battery. Obviously I can't reveal who it is so people may not believe me but I put a lot of faith in this guy.
I'm Here So It Worked-Every Pilot Who Made a Semi Unsafe Decision
sweair From Sweden, joined Nov 2011, 1758 posts, RR: 0 Reply 15, posted (10 months 2 days 21 hours ago) and read 27020 times:
Quoting RNAVFL350 (Reply 13): I am completely confused by this response to PHX787's post. Care to explain what exactly was absurd about his post (reply 13)
He insinuated that Boeing would be happy to do a test flight and declare the plane safe. If they have learned something it is how fast the media spreads negativity and if they would even think acting that way..well it is absurd!
Not even the most greedy bean counter would think of that being a good idea right now, look we took a test flight and now back to business..
PHX787 From Japan, joined Mar 2012, 6525 posts, RR: 16 Reply 16, posted (10 months 2 days 20 hours ago) and read 26337 times:
Quoting sweair (Reply 16): He insinuated that Boeing would be happy to do a test flight and declare the plane safe. If they have learned something it is how fast the media spreads negativity and if they would even think acting that way..well it is absurd!
That wasn't what I was insinuating. I am suggesting that B make these test flights, see the input and output with the battery, possibly show that it was a Yuasa thing, and bada-boom bada-bing paperwork tests etc FAA lifts ED and we're all happy again. If the tests show irregularities with the batteries' performance and/or safety hazards, then appropriate action will be taken, will it not?
And a side note sir- your comment is exactly why 777ER issued a temporary ban on discussion about the battery problems. No need to get all attacky on me.
Back on topic:
I don't know if anyone seen this yet from NH's page, but it says that they're not going to fly the 787 again until at least the 30th of March.
Quote: ANA has revised all flight schedules on the assumption that operations of the Boeing 787 will not recommence before March 30th. Nonetheless, we will continue to cooperate with all parties to ensure and confirm the safety of this aircraft, so that 787 flights may recommence as soon as possible.
Due to the above situation, cancellations and schedule changes have been implemented on certain routes. Also, other routes will be subject to aircraft type changes, including some routes other than those originally scheduled for Boeing 787 operation. Operational information is available from the links below.
An update for operations commencing on March 31st will be provided in this space, as soon as further details are determined.
Includes a schedule:
[Edited 2013-02-10 14:40:50]
One of the FB admins for PHX Spotters. "Zach the Expat!"
ComeAndGo From United States of America, joined Mar 2005, 959 posts, RR: 0 Reply 18, posted (10 months 2 days 20 hours ago) and read 26215 times:
They're doing the test flights to pinpoint the problem. Is it vibrations affecting the batteries, is it humidity affecting the batteries or are the cells too large and creating temperature variations within the cells like some have claimed.
The roadway back to flight is a temporary fix with more spacing between individual cells and a more robust battery case.
The permanent fix is a new battery design that avoids any kind of thermal runaway.
Without knowing the root cause there's no solution.
cornutt From United States of America, joined Jan 2013, 310 posts, RR: 1 Reply 21, posted (10 months 2 days 16 hours ago) and read 25126 times:
Quoting PHX787 (Reply 17): That wasn't what I was insinuating. I am suggesting that B make these test flights, see the input and output with the battery, possibly show that it was a Yuasa thing, and bada-boom bada-bing paperwork tests etc FAA lifts ED and we're all happy again.
I don't think that's what anyone really wants to see accomplished with the test flights, though. If it were me, I'd want the test flight to show that the failure, or at least the type of plate damage seen in the CAT scans of the JAL battery, can be re-created under specific conditions. Once that's done, we have a defined chain of events for how the failure occurs, and from there, we can figure out what to do about it. Presumably there would then be design mods, and an additional test flight to verify the modified battery.
The FAA doesn't care whose "thing" it is. They only care about what the problem is and how is it going to be fixed. Even if it were shown to be a manufacturing problem confined to one batch of batteries (which I doubt at this point), the FAA would want to know what is being done to prevent it from happening again.
RickNRoll From Afghanistan, joined Jan 2012, 603 posts, RR: 0 Reply 22, posted (10 months 2 days 16 hours ago) and read 25014 times:
Quoting PHX787 (Reply 17): That wasn't what I was insinuating. I am suggesting that B make these test flights, see the input and output with the battery, possibly show that it was a Yuasa thing, and bada-boom bada-bing paperwork tests etc FAA lifts ED and we're all happy again. If the tests show irregularities with the batteries' performance and/or safety hazards, then appropriate action will be taken, will it not?
Not quite. Even if the batteries never fail again, the containment system has to be fixed as well.
DTW2HYD From United States of America, joined Jan 2013, 924 posts, RR: 2 Reply 23, posted (10 months 2 days 15 hours ago) and read 24834 times:
Quoting PHX787 (Reply 17): I am suggesting that B make these test flights, see the input and output with the battery, possibly show that it was a Yuasa thing, and bada-boom bada-bing paperwork tests etc FAA lifts ED and we're all happy again. If the tests show irregularities with the batteries' performance and/or safety hazards, then appropriate action will be taken, will it not?
I see few issues, No one is going to trust Boeing/FAA paper tests, not NTSB, not customers, not media, not public. NTSB already warned FAA about single cell testing assumption.
Second if Boeing design assumptions and written specs to Thales/Yuasa were wrong, it is difficult to pin on Yuasa. In a outsourced model Yuasa's responsibility is to live up to the written specs, not what Boeing thinks what a battery system should do. Obviously vendors/sub-vendors will do everything to address the issue, for PR reasons, not legal reasons.