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Lithium batteries in 787 may pose fire issues

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Member
Registered: May 2009
Posts: 309
Location: Winchester, UK
An interesting perspective on this in today's London Sunday Times at http://www.thesundaytimes.co.uk/sto/business/Industry/article1197498.ece
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Cheers, Richard
Member
Registered: May 2009
Posts: 944
Some additional technical details are provided here:

http://www.bloomberg.com/news/2013-01-20/boeing-787-deal-puts-battery-maker-gs-yuasa-in-spotlight.html

What a mess. I hope they can identify a clear chain of events and the root or fundamental issues soon. I have a faded memory that other electrical fires, related to the circuit breaker system (???) developed
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 944
Some additional technical details in this NY Times story, dated Jan 21, 2013:

http://www.nytimes.com/2013/01/21/business/global/ntsb-rules-out-a-cause-for-battery-fire-on-787-dreamliner.html?ref=todayspaper

and here:

https://www.nytimes.com/2013/01/21/business/battery-fire-resolution-may-weigh-on-boeing.html?ref=todayspaper
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Best wishes,

Phil Bunch
« Last edit by Phil Bunch on Mon, 21 Jan 2013 16:46:04 +0000. »
Member
Registered: May 2009
Posts: 944
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 149
Hi Phil,

I think your comments about the efficiency of large multinational systems are certainly relevant - note this is true of Airbus also. Although not a systems engineer or battery expert, I suspect we'll find this is not a "Comet" type of problem, where if I remember correctly the problem was unfamiliarity with the physics of hoop stresses induced by multiple pressurization-depressurization cycles (no supercomputers with finite element codes in those days). I think the underlying issues with modern batteries are pretty well understood and result from the huge demand for exponential increases in energy density in batteries everywhere. This can lead to design compromises and testing problems etc. I was reminded on this just yesterday when running the Google maps app on my iPhone for half an hour resulted in the phone getting almost too warm to handle.

So my guess is that the problem will be found to be in the design of all the fault protection logic and testing etc. and perhaps some subtle battery design 'feature' - more similar to the NASA experience with the Challenger and Columbia accidents. I think Boeing will get their arms around it (they pretty much have to) but the next chapter may be lots of diverts due to 'worry lights' from all the fault protection systems they'll throw at it to make sure they never get a fire.

Cheers,
Torrence
Member
Registered: May 2009
Posts: 309
Location: Winchester, UK
Can anyone suggest why there is a need for the aircraft to have on-board batteries at all?

Surely a ground-based battery would be easy to implement? Or are there needs, other than APU starting, that require battery?
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Cheers, Richard
Member
Registered: May 2011
Posts: 143
It's the last resort when all else fails. An example: stuff like fire extinguishing is hot wired to the battery without any switch in between (hot battery bus) because it needs to be avaialble in the most extreme emergency situations. The next level is wired with a switch in between, which is the standby system (battery bus, etc...). Fire detection is on this level (if I remember...) But even the smallest switching in between degrades the safety level of the complete system.
Member
Registered: May 2009
Posts: 944
Here's a link to the NTSB investigation's web site for the 787, etc:

http://www.ntsb.gov/investigations/2013/boeing_787/boeing_787.html

[edit - added link to latest NTSB report:]

http://www.ntsb.gov/investigations/2013/boeing_787/JAL_B-787_1-24-13.pdf

It would be interesting to review their investigations as they happen, but I suspect it would very quickly become a flood of very technical details and specialized engineering, all but impossible to follow as a civilian. I wonder how much can be discovered by people who aren't highly experienced specialists in battery technologies and/or avionics.
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Best wishes,

Phil Bunch
« Last edit by Phil Bunch on Mon, 28 Jan 2013 19:28:54 +0000. »
Moderator
Registered: May 2009
Posts: 2449
Location: KTMB
The issue with such an investigation is mainly that it is not obvious what happened, therefore you need a good amount of knowledge and gut feeling and luck (chance, i.e., persistance required) to get to the bottom. Highly experienced specialists may not always be the ones that find the clue. But usually they are the ones to confirm the suspicions.


Jeroen
Member
Registered: May 2009
Posts: 772
Location: Sydney, Australia
Richard McDonald Woods wrote
Can anyone suggest why there is a need for the aircraft to have on-board batteries at all?


Here was a close call...

http://www.atsb.gov.au/media/3440510/ao2008003.pdf
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Member
Registered: May 2009
Posts: 309
Location: Winchester, UK
John,
Very interesting document. Many thanks for pointing it out.
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Cheers, Richard
Member
Registered: May 2009
Posts: 772
Location: Sydney, Australia
I don't think I'd read it in detail before - originally it was thought all AC busses were lost, but apparently AC4 stayed in...

but a few more drops of water.... ! :shock:

Hopefully something we can play with in PSX!
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Member
Registered: May 2009
Posts: 944
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 944
_______________
Best wishes,

Phil Bunch
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Location: KTMB
Member
Registered: Jul 2012
Posts: 17
Airbus declared they'd switch from LiIon to NiCad batteries on their upcoming A350 XWB at least on all customer aircraft because of the dreamliner troubles. Only the almost complete A350-prototypes will use the LiIon batteries for their flight testing.

I'd expect Boeing to switch to NiCad too if no root cause for the fires can be found soon.
Member
Registered: May 2009
Posts: 944
Another update by the NY Times, including Boeing's predictions of resuming flights by April of 2013.

https://www.nytimes.com/2013/02/21/business/boeing-to-propose-battery-fixes-to-faa.html?ref=todayspaperhttps://www.nytimes.com/2013/02/21/business/boeing-to-propose-battery-fixes-to-faa.html?ref=todayspaper

I wonder if the theory that the 787 will be approved for flight by April is realistic, considering the multiple battery changes they propose? I personally find it hard to believe that such major changes to the airliner batteries could be implemented and tested within a few months. Regulatory approval is of course another set of issues, as discussed earlier in this thread by Jeroen H.
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 944
As best I can interpret the NY Times account of the FAA/Boeing meeting held on Friday, Feb 22, Boeing has a seemingly impossible task.

https://www.nytimes.com/2013/02/23/business/faa-sets-terms-for-boeings-battery-fixes-on-787.html?ref=todayspaper&pagewanted=print

They must somehow prove that revised batteries and avionics will be safe, yet they don't know specifically what caused the failed batteries to fail. It almost seems like they are trying to act like US automobile salesmen in trying to create an impression of safety without in-depth evidence that their solutions would for sure work. Boeing's very recent projection that the 787 would be flying by April of 2013 sure seems optimistic to me, but obviously I don't know how the FAA and other agencies work. I can't imagine Boeing's executives wanting to resume 787 flights without a clear understanding of how the batteries failed and without thorough, statistically justified evidence that the new batteries have been fixed and that if somehow they do fail that they won't bring an airliner down. Can the battery vendors really create, test, and certify a new lithium battery design in 2 months?

I wasn't aware that it is feasible to stop a lithium fire once it starts, without using unusual fire extinguishing and containment means. There is so much heat and energy released that I can't visualize how one could contain such a fire. But without specific causes identified and fixed in the batteries, it isn't convincing to me that new designs would necessarily be safe. Sort of a Catch 22 situation...

And then there are no doubt a zillion regulatory issues, as well as the FAA not wishing to be seen as unwisely endorsing an unsafe airliner.
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 944
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Best wishes,

Phil Bunch
Moderator
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Location: KTMB
... create drop hatch and quick release solenoid ...
Member
Registered: May 2009
Posts: 497
Looks like progress is being made:

http://www.bbc.co.uk/news/business-21764282
Moderator
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Location: KTMB
Watch the wording: the design plan has been approved. This typically means the PROCESS to design and test has been approved -- not necessarily the design, if there is one.

I got weathered by FAA speak over the last years :-)
Member
Registered: May 2009
Posts: 944
I'm surprised that Boeing isn't rushing forward with previously approved (NiCd?) battery packs and working to redesign lithium batteries at a later date. I would think that they couldn't attempt a parallel NiCd redesign in secret.

It seems like they are betting everything on somehow quickly proving that modified lithium batteries won't fail or if they do fail a fire won't spread or create too excessive fumes or smoke.

It would be interesting to know what Boeing's strategy and a realistic redesign/recertification timeline really are.
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Best wishes,

Phil Bunch
Member
Registered: May 2009
Posts: 944
Another NY Times update, with some interesting discussions and quotes:

https://www.nytimes.com/2013/03/13/business/faa-backs-boeing-plan-for-battery-test.html?ref=todayspaper&pagewanted=all&pagewanted=print

The effort to get the 787 back into flight seems to be especially political in nature, aimed at using the FAA's processes to obtain a quick approval.

But what good will it do Boeing and the 787 if they manage to get the lithium batteries approved and then additional fires and problems start showing up? Even with the improved battery design and added safety features, a battery fire wouldn't be something that is welcome during a flight.
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Best wishes,

Phil Bunch
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Registered: May 2009
Posts: 2449
Location: KTMB
How much money do they bleed every day?

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