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NTSB identifies origin of JAL Boeing 787 battery fire
- getpost 14y agoIf 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 http://news.ycombinator.com/item?id=5137641
- ljoshua 14y agoWoah, the photos of the charred battery are fairly dramatic: http://www.ntsb.gov/investigations/2013/boeing_787/boeing_787.html http://www.ntsb.gov/investigations/2013/boeing_787/boeing_78...
- jlgreco 14y agoMuch smaller than I would have expected. That thing can start an engine that large?
- datasage 14y agoAs I understood it, these batteries power auxiliary systems.
- tfe 14y agoThese 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 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_07/article_02_4.html http://www.boeing.com/commercial/aeromagazine/articles/qtr_4...
- jlgreco 14y agoAhh, that makes more sense. Thanks!
- WalterBright 14y agoEarly 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 14y agoI 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)
- moreati 14y agoFrom the captions, this battery starts the APU (and in an emergency, critical systems). The APU starts the main engines http://en.wikipedia.org/wiki/Auxiliary_power_unit http://en.wikipedia.org/wiki/Auxiliary_power_unit
- magic_haze 14y agoInteresting 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-787-battery-fundamentally-unsafe-381627/ http://www.flightglobal.com/news/articles/elon-musk-boeing-7...), but it is shocking how badly Boeing got its estimates wrong. Does anyone know exactly how they came up with these numbers?
- vermontdevil 14y agoFrom 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.
- dmethvin 14y agoIt really feels a lot like the shuttle disasters, with Boeing playing the part of NASA and delegating work out to contractors who feel they must get something out or risk losing the next big contract. God forbid if this does come down to a disaster it will be even more difficult to unravel, since this time it will cross political and cultural boundaries.
- wpietri 14y agoThat 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 14y agoI have an hp48 emulator on my phone, I use it all the time these days.
- hsmyers 14y agoWere 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 14y ago>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/35279938_1_space-exploration-technologies-satellites-eelv http://articles.washingtonpost.com/2011-10-16/business/35279...
- rst 14y agoBoeing 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).
- deleted 14y ago[deleted]
- eduardordm 14y agoThe 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 14y agoAnd then when the TSA bans batteries in checked luggage everybody says, zomg, my constitutional rights are being trampled.
- jlgreco 14y agoOh 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.
- United857 14y agoAt least one: http://en.wikipedia.org/wiki/UPS_Airlines_Flight_6#FAA_Reaction http://en.wikipedia.org/wiki/UPS_Airlines_Flight_6#FAA_React...
- rayiner 14y agoRisk management for rare events does not mean only taking precautions against things that have already caused problems.
- jlgreco 14y agoI don't think I have suggested otherwise.
- tedunangst 14y ago
- nferiuernjkf 14y agoWho 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 14y agoRead 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 14y agoChairman 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 14y agoOf 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 14y ago"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.
- gesman 14y agoNot sure about Boeing, but batteries made in USA never failed me.
- OGinparadise 14y agoThat 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 14y agoMy 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 14y agoThe 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.]
- mckoss 14y agoThis 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.
- ChuckMcM 14y agoInteresting 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.
- Wingman4l7 14y agoExcept 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 14y agoThis. 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.
- ars 14y agoReminds me of the dell lithium ion battery recall that was caused by metal fragments in the cell during manufacturing causing shorts in the cells.
- batterypro 14y agoThe 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