
NTSB identifies origin of JAL Boeing 787 battery fire - MattRogish
http://www.ntsb.gov/news/2013/130207.html
======
magic_haze
Interesting bits:

> the majority of evidence from the flight data recorder and both thermal and
> mechanical damage pointed to an initiating event in a single cell. That cell
> showed multiple signs of short circuiting, leading to a thermal runaway
> condition, which then cascaded to other cells.

> Boeing ... determined that the likelihood of a smoke emission event from a
> 787 battery would occur less than once in every 10 million flight hours ...
> there have been two critical battery events on the 787 fleet with fewer than
> 100,000 flight hours.

Seems like Musk was right in his guess after all
([http://www.flightglobal.com/news/articles/elon-musk-
boeing-7...](http://www.flightglobal.com/news/articles/elon-musk-
boeing-787-battery-fundamentally-unsafe-381627/)), but it is shocking how
badly Boeing got its estimates wrong. Does anyone know exactly how they came
up with these numbers?

~~~
vermontdevil
From what I have been reading, it seems non-engineering people have taken over
Boeing. I wouldn't be surprised these suits have been pressuring everyone to
get the 787 out and the culture goes from there.

~~~
wpietri
That reminds me of HP. I grew up using their awesome technical products (RPN
represent!) and now I get sad every time I see them in the news.

Have any pointers on the switch from engineering-driven to whatever they are
now? I'd love to read more.

~~~
InclinedPlane
I have an hp48 emulator on my phone, I use it all the time these days.

------
getpost
If I understand correctly, this finding seems consistent Elon Musk's
hypothesis on how the battery is fundamentally unsafe. "Large cells without
enough space between them to isolate against the cell-to-cell thermal domino
effect means it is simply a matter of time before there are more incidents of
this nature,"

<http://news.ycombinator.com/item?id=5137641>

------
ChuckMcM
Interesting report. Elon Musk's comments aside, one would think that Boeing
would short a cell on purpose in a battery pack to verify their assertion that
the failure of one of the cells would not propagate to other cells.

That said, if this is the proximate cause of the smoke and fire then it points
to some ways to fix the problem that don't involve completely re-designing the
way the plane is built which is good news for Boeing.

As for the 'other chemistry' arguments, one of the challenges of various
battery chemistry is the rate of charge and the rate of discharge. My
Battlebot team went through a number of battery packs for our robots[1] and
found that the energy-density, charge rate, and discharge rate was one of
those "pick any two" scenarios. A pain to work around.

------
hsmyers
Were I the folks in charge at Boeing, I'd be looking at a joint venture with
Mr. Musk, starting today. I suspect that the difference in estimates are owed
to the usual testing phenomenon---you test for what you can imagine and that
is heavily conditioned by your expectations. Same reason that the folks who
write software/engineering/whatever should never test it. You need a team
who's main goal in life is to ruin someone else's day. When I worked for EA,
the testing team was the biggest PIA you could imagine. But if they could come
up with bugs, imagine what real life could do. (Pesky 8-year old
kids...<grumble/>)

~~~
jlujan
>Were I the folks in charge at Boeing, I'd be looking at a joint venture with
Mr. Musk, starting today.

Boeing and Lockheed are pretty much the only space flight companies working
with the government. Musk has an issue with this which is why his battery
predictions are so enjoyable.

[http://articles.washingtonpost.com/2011-10-16/business/35279...](http://articles.washingtonpost.com/2011-10-16/business/35279938_1_space-
exploration-technologies-satellites-eelv)

~~~
rst
Boeing and Lockheed are major players, and you're right about the rivalry, but
they're not the only ones. ATK (the former Thiokol) is a major player in the
Space Launch System project, and politically very well connected; there are
also smaller fry like SpaceX and Orbital Sciences (makers of the Pegasus air-
launched rocket, and the other commercial supplier for ISS cargo resupply).

------
ljoshua
Woah, the photos of the charred battery are fairly dramatic:

[http://www.ntsb.gov/investigations/2013/boeing_787/boeing_78...](http://www.ntsb.gov/investigations/2013/boeing_787/boeing_787.html)

~~~
jlgreco
Much smaller than I would have expected. That thing can start an engine that
large?

~~~
tfe
These batteries (or more often, ground power) are used to first start a small
turbine engine in the tail (APU) which generates the compressed air used to
start the main engines.

Further reading: <http://en.wikipedia.org/wiki/Auxiliary_power_unit>

Edit: after further research, it seems compressed air is not used on the 787.
It's all electric (two generators on the APU and on each engine):

"The power source for APU starting may be the airplane battery, a ground power
source, or an engine-driven generator. The power source for engine starting
may be the APU generators, engine-driven generators on the opposite side
engine, or two forward 115 VAC ground power sources. The aft external power
receptacles may be used for a faster start, if desired."[1]

1\.
[http://www.boeing.com/commercial/aeromagazine/articles/qtr_4...](http://www.boeing.com/commercial/aeromagazine/articles/qtr_4_07/article_02_4.html)

~~~
jlgreco
Ahh, that makes more sense. Thanks!

~~~
WalterBright
Early jet aircraft used a ground cart to provide power to get the engines
started.

Evidently adding the APU saves enough money to justify its significant weight.

~~~
tfe
I think it's less about money and more about stuff like:

\- backup power for emergencies \- allowing attempted engine restarts in the
air \- allowing the airplane to be self-sufficient should it be forced to land
somewhere without ground equipment (or big enough ground equipment)

------
nferiuernjkf
Who did the what now???

    
    
      As investigators work to find the cause of the initiating
      short circuit, they ruled out both mechanical impact damage
      to the battery and external short circuiting.
    

Sounds to me like no orgin was identified at all. All they know is that the
fire started because of short-circuiting. But what caused the short
circuiting? I don't know?

~~~
pdonis
Read a bit further:

 _Chairman Hersman said that potential causes of the initiating short circuit
currently being evaluated include battery charging, the design and
construction of the battery, and the possibility of defects introduced during
the manufacturing process._

They don't know the precise cause, but they have narrowed it down to a few
possibilities.

~~~
grecy
_Chairman Hersman said that potential causes of the initiating short circuit
currently being evaluated include battery charging, the design and
construction of the battery, and the possibility of defects introduced during
the manufacturing process._

Paraphrase:

"The thing we built doesn't work properly, and we think it could be because of
how it works, how we designed it, or how we built it".

Sounds like a useful assessment.

~~~
HeyLaughingBoy
Of course it's useful. It's just like debugging code: when the bug first
surfaces, the cause can be anything in a large space. As you learn more of the
characteristics of the bug, the problem space grows smaller until you
eventually identify the root cause.

They've just learned what areas to focus on.

~~~
maaku
"how it works, how we designed it, or how we built it" is pretty much
inclusive of every possibility and doesn't rule anything out. In other words,
useless.

~~~
pdonis
The NTSB is not saying what you are claiming. They are only talking about
those possibilities in reference to one specific failure mode: a short circuit
in a single battery cell causing a fire that spreads through the entire
battery. That rules out a lot.

------
Wingman4l7
Except they actually haven't, yet:

 _Chairman Hersman said that potential causes of the initiating short circuit
currently being evaluated include battery charging, the design and
construction of the battery, and the possibility of defects introduced during
the manufacturing process._

~~~
codex
This. It's pretty obvious what happened to the battery; the question is why,
and why testing didn't bring the issue to light. Is it a maintenance problem?
A quality control issue in manufacturing? Something unknown about the physics
of flight or the interplay between various electrical systems that reduces the
safety margin? Unknown at this time.

------
eduardordm
The temperature those batteries (and those used in newer RC planes - LiPo)
burn is ridiculous.

You buy some electronic/hobby equipment while traveling, put in your luggage
among your clothes. In mid-flight those things get shorted and everybody is
doomed.

Those batteries can ignite when shorted due to shock or tearing - which is
pretty much what happens to some luggage on every flight.

~~~
tedunangst
And then when the TSA bans batteries in checked luggage everybody says, zomg,
my constitutional rights are being trampled.

~~~
jlgreco
Oh I don't know, such a ban might be uncharacteristically rational for the
TSA. ...actually, how many plane crashes have Li-ion battery failures in
luggage caused? No it wouldn't be, a ban like that would be par for the
course.

~~~
cpleppert
The luggage compartment is much hotter than the flight deck, especially on a
freighter. If your luggage is parked in the hold during summer when the air
conditioning units are off that is a major concern. There is concern that DHL
flight 6 could have crashed for that reason.

~~~
jlgreco
What we know is that, for whatever the reason, the rate of catastrophic
failure has been quite low in the past.

When new information becomes available we are able to update our risk
assessment, it isn't necessary for us to wait for more plane crashes. I don't
see any new information here though, the risks posed by Li-ion batteries and
fires on airplanes have been well understood for quite some time.

------
mckoss
This seems a politically motivated press release by the NTSB. Boeing certainly
wants to get their planes back in the air. This misleading declaration that
NTSB has identified a "cause" is the first step in removing the grounding
order on the aircraft.

 _Chairman Hersman said that potential causes of the initiating short circuit
currently being evaluated include battery charging, the design and
construction of the battery, and the possibility of defects introduced during
the manufacturing process._

------
batterypro
The choice of Li-ion battery saved only 30 kg over a same performance and
specifications NiMH battery used without a single insident in 6.6 million
hybrids produced over the last decade. There was no valid reason to use Li-ion
system in this case. Even only 1 fire in 10 million flight hours mens a fire
every year once 1500 Dreamliners ar flying as Boeing hopes. Switch the battery
now, it is totally unnecessary risk

------
ars
Reminds me of the dell lithium ion battery recall that was caused by metal
fragments in the cell during manufacturing causing shorts in the cells.

------
gesman
Not sure about Boeing, but batteries made in USA never failed me.

~~~
OGinparadise
That really solves it then, who needs testing, FAA, NTSB and other alphabet
agencies!

Maybe you should tweet to Boeing's CEO, let them run to CVS or Radio Shack to
buy a few US made batteries and call it a day.

~~~
gesman
My point is the more we outsource important pieces to the cheaper ends of the
globe - the more expensive it becomes for everyone to fix the consequences.

~~~
snogglethorpe
The 787 batteries are built in Japan, which is not at all cheap, and in
general has a much better reputation for quality and reliability than the
U.S... This is _particularly_ true for high-end specialty products—like
airliner batteries.

[Japanese companies outsource all their cheap goods manufacturing to other
countries.]

