Problems with the Dreamliner battery

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The discussion centers on the safety issues surrounding the Boeing Dreamliner's lithium-ion battery, particularly following incidents of battery fires. Experts highlight that while Boeing has implemented multiple systems to monitor and control battery charging, the risk of internal cell shorts leading to fires remains a concern. The unique electric power distribution system of the Dreamliner is noted as a significant innovation, but it also raises questions about potential failures and redesign needs. Some participants express skepticism about the aircraft's safety assurances, emphasizing the challenges Boeing faces in resolving these issues. Overall, the consensus reflects a mix of concern and recognition of the Dreamliner's groundbreaking design amidst ongoing safety challenges.
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Surprised there hasn't been a thread for this big topic. Any experts out there want to weigh in on what the problem is, how it can be fixed and what this means for Boeing?

As Boeing and airline officials sought to assure travelers of the overall safety of the world's newest jetliner, federal safety officials Thursday painted a graphic picture of a disaster averted, displaying the charred remnants of a battery that "spewed molten electrolytes" from its container shortly after landing in Boston earlier this month.

http://www.cnn.com/2013/01/24/travel/dreamliner-investigation/index.html?hpt=hp_t1
 
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The thermite-style failure mode reactions are well know so I'm sure the calculation was made showing the frequency of it happening being very low. At least the means to handle it until burning out seems to be working.

http://www.fire.tc.faa.gov/pdf/systems/lithium-ion_battery_04112006.pdf
http://www.wpi.edu/Pubs/E-project/Available/E-project-121306-105357/unrestricted/CPSCIQP2006.pdf
http://seattletimes.com/html/businesstechnology/2020199686_787batterysafetyxml.html?prmid=4939

To completely rule out any catastrophic high-energy fire or explosion that could result from overcharging a battery, Sinnett said, Boeing designed four independent systems to monitor and control the battery charge.

However, he conceded that if an internal cell shorts and overheats, “the electrolyte can catch on fire and that can self-sustain.”

“Something like that is very difficult to put out,” Sinnett said. “Because the electrolyte contains an oxidizer, fire suppressants just won’t work.”

Boeing’s design solution is to contain that outcome until the combusting battery cell or cells burn out.

“You have to assume it’s not going to go out,” Sinnett explained. “You have to assume that it’s going to go and that it’s going to expend all of its energy.
...
During testing of a prototype charging-system design in the 2006 incident, “the battery caught fire, exploded, and Securaplane’s entire administrative building burned to the ground,” according to a summary by the administrative law judge in a related employment lawsuit.
 
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There have been many problems with the Dreamliner but this was expected. It represents, by all accounts that I've heard, the biggest change in the construction of commercial airliners since we started building them. Note that it doesn't even have an airframe by traditional standards. So none of this is surprising. And they have probably solved problems far more difficult than this along way a thousand times over before the craft was certified for flight.

Obviously everyone is anxious to get any remaining issues resolved but it seems to be a phenomenal aircraft. AFAIK, this and the previous delays are mainly PR and cash flow issues and not surprising from an engineering perspective.
 
Ivan Seeking said:
It represents, by all accounts that I've heard, the biggest change in the construction of commercial airliners since we started building them.

Indeed, and the outcome is pretty much what you would expect from a project with so many unknowns - delivered years late, way over budget, and doesn't work.

Igmore all the BS public relations that "it's safe to fly". If anybody could come up with a creative argument that is it WAS safe to it was safe to fly, it would still be flying.

The FAA also has some backtracking to do, considering it agreed new regulations specifically to certify the new 787 electrical system. I'm not expecting any quick resolution for this.

Boeing have bet the farm on this one. The only good news here is, the 787 hasn't killed anybody ... yet.
 
AlephZero said:
Indeed, and the outcome is pretty much what you would expect from a project with so many unknowns - delivered years late, way over budget, and doesn't work.

Igmore all the BS public relations that "it's safe to fly". If anybody could come up with a creative argument that is it WAS safe to it was safe to fly, it would still be flying.

The FAA also has some backtracking to do, considering it agreed new regulations specifically to certify the new 787 electrical system. I'm not expecting any quick resolution for this.

Boeing have bet the farm on this one. The only good news here is, the 787 hasn't killed anybody ... yet.

Why so negative? An Airbus fan I presume? :biggrin: There are issues but internally I don't hear any concerns like this.

Of all the concerns that one might have for something this innovative, a battery problem seems pretty hard to worry about. There have been far bigger bumps along the way.
 
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Boeing 787 Electrical System

The 787 has been in the news much after recent battery fires. In media aricles I found several references to a possible interaction between the battery and the 787's unique electric power distribution system.

What's so unique about the 787's electric power distribution system?

Can anyone please provide a link to an article about it?

Thanks.
 


anorlunda said:
The 787 has been in the news much after recent battery fires. In media aricles I found several references to a possible interaction between the battery and the 787's unique electric power distribution system.

What's so unique about the 787's electric power distribution system?

Can anyone please provide a link to an article about it?

Thanks.

This is the closest I've found so far, but it's not much help:

http://www.newairplane.com/787/design_highlights/#/visionary-design/systems/electric-architecture

Click on the "Read More" button in the upper right. It only seems to be saying that there are more electrically operated items and fewer pneumatic/hydraulic items...
 
And this DesignNews interview with Boeing's lead engineer on the 787 seems to be saying the same things -- more electricity power devices (like air conditioning) and less pneumatics...

http://www.designnews.com/document.asp?doc_id=222448&dfpPParams=ind_184,aid_222448&dfpLayout=article

.
 
  • #10


anorlunda said:
The 787 has been in the news much after recent battery fires. In media aricles I found several references to a possible interaction between the battery and the 787's unique electric power distribution system.

What's so unique about the 787's electric power distribution system?

Can anyone please provide a link to an article about it?

Thanks.
I think it is the objective to reduce mass, which means increased power density. The Li-batteries have a smaller mass, but apparently flammable electrolytes.

As far as I know, aircraft use electricity from generators driven from the jet engines. When the engines are shutdown and before the external power supply is connected, the batteries provide power. Some aircraft have small turbine powered auxilliary power units (APUs) in the tail.
 
  • #12
Ivan Seeking said:
Why so negative? An Airbus fan I presume? :biggrin: There are issues but internally I don't hear any concerns like this.
I tell it the way I see it. Both companies have made some pretty good aircraft, and some less good ones.

IMO some of the other 787 problems in the news (e.g. brake failure, fuel leak, cracked window) ARE in the "no big deal" category. You don't ground an aircraft type permanently worldwide because of stuff like that. But the 787 electrical system is in a different league - it's a totally new concept and covers far more functionality than on any previous commercial aircraft. If that doesn't work, the problems are big time, and could involve huge amounts of redesign work - including knock-on effects like redesigned engines.

There were some "11th hour" electrical problems with the flight test programme back in 2010, which caused more delays to entry into service. Unsurprisingly, there's not much in the public domain about what really happened back then, but sometimes stuff like that comes back to haunt you...

One measure of the seriousness of grounding an entire aircraft type is how rarely it happens. The last time was back in 1979 (the DC-10, following a crash).
 
  • #14
spook - your link suggests a safer alternative battery?

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

at first glance one has to ask "why didn't they... ?"

I have a strong opinion - some parts of machines should remain mechanical instead of electric. I won't own an automobile with electric steering or a computer between my foot and throttle & brakes.
Or a huge li-ion battery right under my butt. Some years back a small one in my pocket nearly set my pants afire.

old jim
 
  • #15
jim hardy said:
spook - your link suggests a safer alternative battery?

http://en.wikipedia.org/wiki/Lithium_iron_phosphate_battery

at first glance one has to ask "why didn't they... ?"

I don't know why but lithium cobalt oxide batteries would not have been my choice for a large electrical system design where safety was a top priority. I've been designing an off-grid solar battery management system for a future retirement home and will never have them inside my house at the power levels I need for daily power storage (>5kWh daily). They just have really bad failure modes because IMO the lithium metal reaction is intrinsically unsafe as Boeing was using 4X redundancy in the BMS to prevent problems that are still happening.

Remember Dell?
http://www.telegraph.co.uk/news/1526424/Exploding-laptops-prompt-Dell-battery-recall.html
 
  • #16
Can they just work with the current battery and retrofit an emergency battery jettison system? :devil:
 
  • #19
The FAA Boeing 'special battery conditions' http://www.gpo.gov/fdsys/pkg/FR-2007-10-11/pdf/E7-19980.pdf

Boeing planned to change the batteries:
http://www.flightglobal.com/news/ar...-787-lithium-ion-battery-service-life-224663/

As Boeing activated the electrical system of its 787 for the first time last week, the airframer acknowledged that it was exploring a change to its power system for production aircraft due to longevity concerns.

Boeing will move away from its original lithium ion battery design for its main and auxiliary power units, flight-control electronics, emergency lighting system and recorder independent power supply. Instead, Boeing is investigating the incorporation of manganese inside the lithium ion battery to boost service life.
 
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  • #20
Thanks spook !
i never dreamed there are so many varieties of Li batteries..

From American Manganese:
http://www.canadianminingjournal.com/press-releases/story.aspx?id=1002006696
(bold mine - jh)
Green Car Report states lithium ion batteries are a family of products having very different performance characteristics resulting from incorporating specific alloying metals into the battery chemistry. Lithium plus manganese or/and nickel (or other metals) typically carry less energy per volume than lithium plus cobalt, but are widely viewed as less susceptible to overheating. The battery chemistry utilized by the Dreamliner was Lithium Cobalt Dioxide (LiCoO2); similar to that used in laptop computers and cell phones. American Manganese Inc.'s ("AMY") product would be Lithium Manganese Dioxide (LiMn2O4), or spinel, similar to rechargeable batteries used in the Chevy Volt. Both of these battery chemistries come under the generic heading "lithium Ion Batteries".

and from Battery University:
credit for the graph: http://batteryuniversity.com/learn/article/types_of_lithium_ion
li_9(1).jpg

Battery University's page is worth a look. It rates cobalt variety less safe.
 
  • #22
Any change of battery system won't be a quick fix, because of the amount of re-certification required. This guy is talking about NiH, but I think the same would apply to a different sort of Li.
http://news.cnet.com/8301-11386_3-5...ry-solution-may-keep-787-grounded-until-2014/

Given the current situation, convincing anybody that you were confident about an accelerated test program (i.e. proving the safe battery life is X years with less than X years of testing) might be a tough argument to win.

But if they can demonstrate ANY safe life, they could resume flying so long as they can make enough replacement batteries. There have been instances of commercial aircraft flying with major engine parts replaced every 50 hours. That's as nice for the airlines as having to take your car for an all-day service once a week, for the indefinite future, but it's better than not flying at all.
 
  • #23
nsaspook said:
I see no isolation of the internal electronics from the cells and the boards don't seem to be potted to seal them from possible out-gassing.

Aside from that: since "everybody" knows Li batterrs do present a fire risk in some circumstances, why did somebody put them in a place where the fumes from a fire would vent into the passenger cabin and/or flight deck ?

Given that even aircraft engines have fire extinguishers big enough to put them out (and more than one per engine, in case the first extinguisher doesn't operate), it shouldn't be impossible to put out a battery fire - so long as all the nasty stuff gets vented overboard, and not into the lungs of the self-loading cargo.
 
  • #24
AlephZero said:
Aside from that: since "everybody" knows Li batterrs do present a fire risk in some circumstances, why did somebody put them in a place where the fumes from a fire would vent into the passenger cabin and/or flight deck ?

If you read the "special battery conditions" link, the ALPA asks questions about that and other topics and the FAA implies that Boeing has certified that the chances of it happening (fumes from a battery fire) is "extremely remote".

http://www.gpo.gov/fdsys/pkg/FR-2007-10-11/pdf/E7-19980.pdf
 
  • #27
nsaspook said:
If you read the "special battery conditions" link, the ALPA asks questions about that and other topics and the FAA implies that Boeing has certified that the chances of it happening (fumes from a battery fire) is "extremely remote".

The words "Extremely remote" have a precise definition in this context, namely that the expected rate of occurrence is demonstrated to be less than 1 event per 1 billion flying hours. In simple terms, it means something that is so unlikely to happen that you don't care if it kills everbody on the plane, and most likely you can't make any meaningful design changes to mitigate it anyway (which is certainly not the case if we are talking about a battery fire).

To put "1 billion flying hours" in context, a total manufactured fleet of say 2000 aircraft, with a life of 50 years each, flying 5000 hours a year, would accumulate half a billion flying hours - so there would be a 50/50 chance you would have one "extrememely remote" event in the complete in-service history of the aircraft type.

To clarify your quote, Boeing don't "certify" this on their own. First, the FAA agrees a procedure for demonstrating compliance with the condition. That might be purely theoretical (based on calculation), and/or involve experimental testing. Boeing (or their subcontractors or partners) then carry out the demonstration. The FAA then checks that the demonstration was carried out to their satisfaction, and if so the FAA grants the certification.

The "checks" can mean FAA observers being present while the demonstration work is being done, if they so wish (and they do sometimes so wish!).

So, following that process, what we actually have is two separate events, each in an aircraft with less than 100 hours flying time. Yeah, right, so there's nothing to worry about over the demonstration process here - not!
 
  • #28
Greg Bernhardt said:
Dreamliner: No fault found with Boeing 787 battery
http://www.bbc.co.uk/news/business-21230940

I don't agree, the current battery system is intrinsically unsafe for use in aircraft. The amount of control feedbacks needed to maintain the narrow range of 'safe' operation , stop a positive feedback loop of higher and higher energy releases combined with the need for much better containment makes me think they should have never been approved by the FAA for commercial flights.

Lithium Iron Phosphate might be a possible alternative but it might take years to redesign in.
http://www.mpoweruk.com/lithium_failures.htm
 
  • #29
AlephZero said:
To clarify your quote, Boeing don't "certify" this on their own. First, the FAA agrees a procedure for demonstrating compliance with the condition. That might be purely theoretical (based on calculation), and/or involve experimental testing. Boeing (or their subcontractors or partners) then carry out the demonstration. The FAA then checks that the demonstration was carried out to their satisfaction, and if so the FAA grants the certification.

I agree and have been on both sides of a product needing certification (non-aircraft). For anything that pushes the envelope of current technology the 'OEM' usually writes the new test specs as most 'agency's' with few exceptions are far from the experts in the field. Usually the thicker the report the better. :smile:
 
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  • #30
nsaspook said:
... The amount of control feedbacks needed to maintain the narrow range of 'safe' operation , stop a positive feedback loop of higher and higher energy releases combined with the need for much better containment makes me think they should have never been approved by the FAA for commercial flights.
...
http://www.mpoweruk.com/lithium_failures.htm

when one looks at that narrow safe operating area window in your link, one wonders what is time lag between internal cell temperature and the sensor reporting it to computer. In process control we sometimes use derivative to extrapolate back through time delays to process...

I'm keeping an ear out for details of that test in 2006 where a prototype test battery burned down the building housing the test lab. That sounds like a huge flag that these batteries need "kid glove" treatment.

The more significant problem may become the emerging reports that Boeing was warned about the safety of the batteries and associated systems as early as 2006. Those reports center on the actions of whistleblower Michael Leon.

Aviation reporter and blogger Ben Sandilands writes in Plane Talking that while employed at Securaplane, which brought together mission critical battery assemblies for the 787, Leon wrote a report on the battery technology planned for the 787 saying it was a flight of safety risk and that substitute battery technology should be used. A month later, Securaplane's main buildings were burned to the ground when a battery test went wrong. Leon was injured in the blaze. Securaplane reportedly tried to force Leon out of the company when he refused to ship what he considered an unsafe battery assembly to Boeing for use in the 787. That assembly later malfunctioned when installed in a prototype airframe.
http://www.aero-news.net/index.cfm?do=main.textpost&id=66f459f8-4d6b-452b-961a-6b80dc4830a1
Disclaimer - i come from Nuke industy. Some whistleblowers are great folks and some are Don Quixotes. Time will tell about Mr Leon, i have no inside scoop.

old jim
 
  • #31
http://www.ntsb.gov/news/2013/130127.html

Here is a NTSB media brief from a few days ago. http://www.youtube.com/watch?v=wVMkt3sFwh0&feature=youtu.be

My comments in a earlier post about the lack of circuit board protection is related to this: http://www.newsdaily.com/stories/bre90o0gk-us-boeing-dreamliner-japan-circuitboard/

Typically on a system that monitors a possible hazardous process there is a containment space and isolated protected controller area for the monitor and control electronics so if there is a problem the actual controller can be examined and not be turned into a useless cinder of carbon.
 
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  • #32
http://seattletimes.com/html/businesstechnology/2020241385_787deadbatteriesxml.html

An interesting article from the Seattle Times aerospace reporter notes that 100 to 150 of the lithium-ion 787 batteries have been returned to the manufacturer, Yuasa. The troubles with them at first sight seem separate from the two failures which have grounded the fleet, but the electrical system which monitors and controls the batteries is being closely scrutinized by the NTSB and other agencies.

Respectfully submitted,
Steve
 
  • #34
From that FAA airworthiness directive linked by spook:
The service information describes procedures for replacing lithium-ion main aircraft batteries, ..., with Ni-Cad or lead acid batteries. The agency is issuing this AD following evaluation of all the relevant information and determined the unsafe condition described previously is likely to exist or develop in other products of the same type design.

well, some engineering manager is taking his lumps."Cutting Edge Technology" can cut one's career short.old jim
 
  • #35
This is a complete WAG :redface: but maybe we are seeing the effects of strong EM fields on the metal foils that are in tight coils inside each cell when operated at high energy combined with high density levels. Looking at the length of the foils from the Dreamliner cells they would seem to have a fairly large inductance. Rapid current changes from loads or from being charged at high variable rates could be causing some sort of voltage or current non-uniformity inside the cells from the magnetic field effects.
 
  • #36
It emerged on Wednesday [Jan 30] that ANA, the largest operator of the 787, had problems with the lithium-ion batteries on its Dreamliners before the emergency landing on January 16.

ANA replaced Dreamliner batteries on 10 occasions last year because of faults with this equipment or related components, although the airline and Boeing said safety was not compromised.
... from http://www.ft.com/cms/s/0/79906f2e-6ac8-11e2-9871-00144feab49a.html#axzz2JV7ZNnGX

I'm sticking with my original "best guess": there won't be a quick fix for this.

An interestng choice of words in the FT article: Boeing is "assuming" (not "forecasting"!) no significant financial impact from all this. Elsewhere, I've seen an estimate that a grounding to the end of 2013 would knock about $7bn off their 2013 earnings, plus knock-on effects on canceled orders and other future business.

EDIT: Those 10 battery incidents at ANA were on a fleet of just 17 aircraft :eek::eek:
 
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  • #37
nsaspook said:
This is a complete WAG :redface: but maybe we are seeing the effects of strong EM fields on the metal foils that are in tight coils inside each cell when operated at high energy combined with high density levels. Looking at the length of the foils from the Dreamliner cells they would seem to have a fairly large inductance. Rapid current changes from loads or from being charged at high variable rates could be causing some sort of voltage or current non-uniformity inside the cells from the magnetic field effects.

Batteries have a ripple current rating, just like capacitors. Manufacturers caution about ripple in the charger output.

Ripple current
Batteries, as DC devices, prefer to have only DC imposed
on them. The charger’s job is to convert AC into DC but
no charger is 100% efficient. Frequently, filters are added
to chargers to remove the AC current from the DC output.
The AC current on the DC is called ripple current. Battery
manufacturers have stated that more than about 5 A rms
of ripple for every 100 Ah of battery capacity can lead to
premature failure due to internal heating. Ripple voltage is
not a concern since it is the heating effect of the ripple current
that damages batteries. The 5% ripple current figure is
a rough estimate and depends also on the ambient temperature.
Ripple current can increase slowly as the electronic
components in the charger age.
http://www.artec-ingenieria.com/pdf/...uide_en_LR.pdf

Clearly, high crest factor waveform has more heating value than sinewave.
And high frequency would shift that load to the foil nearest the terminals for reason you stated.

I once had to tame some loads - we had SCR style inverters modulating 135 volt 1000 AH batteries to the tune of 100 volt spikes. Their currrent draw was not constant, they drew it in huge gulps. We added one microfarad per milliamp across inverter inputs to calm the battery bus.

So what you suggest is possible.
Ripple and its heating can come either from charger or load.
I'd wager the charger is well behaved,
but the loads are a wag for me, too. In fact an Un-Scientific one, USWAG.
 
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  • #38
http://seattletimes.com/html/businesstechnology/2020275838_boeingoutsourcingxml.html

The latest in a series of Seattle Times aerospace reporter articles into the 787 electrical woes.

As an off-and-on employee of The Boeing Company from 1968 to 2005, in various positions on all commercial airplane programs, I can relate to the sentiments expressed in the article. The Company may indeed be embroiled in something of a fiasco, but I deeply hope and believe it has the ability and time it needs to recover. My pension may depend upon it!

Respectfully submitted,
Steve
 
  • #39
This seems more related to the current problem.

http://seattletimes.com/html/businesstechnology/2020241162_787battery29xml.html?prmid=obinsource

EaglePicher’s key test — proving that a battery explosion is contained within the box — is one such certification test pre-agreed as satisfying the FAA’s conditions.

The company’s website contends that overcharge explosion tests on its battery were repeated successfully multiple times and concludes that “even during this worst-case scenario, the (battery) is able to contain a thermal event.”
...
However, according to a detailed account of the 787’s battery-fire protection system provided by Sinnett, Boeing’s containment plan did not envisage confining the accident entirely inside the battery box.

Sinnett said Boeing had to demonstrate to the FAA that it had multiple redundant safety mechanisms that ruled out the worst-case scenario that EaglePicher’s test simulates: an overcharged battery explosion
 
  • #40
http://www.thestate.com/2013/02/05/2619386/japan-787-probe-finds-thermal.html#.URGs-uDlAW0

The Japan Transportation Safety Board said that CAT scans and other analysis found damage to all eight cells in the battery that overheated on the All Nippon Airways 787 on Jan. 16, which prompted an emergency landing and probes by both U.S. and Japanese aviation safety regulators.

They also found signs of short-circuiting and "thermal runaway," a chemical reaction in which rising temperature causes progressively hotter temperatures. U.S. investigators found similar evidence in the battery that caught fire last month on a Japan Airlines 787 parked in Boston.

http://mainichi.jp/english/english/newsselect/news/20130206p2g00m0dm001000c.html

All eight cells of the battery installed in the ANA plane showed heat-caused damage, Norihiro Goto, chairman of the Japan Transport Safety Board, said at a press conference.

"Cells 3 and 6 were severely damaged and Cells 1, 2, 7 and 8 were swollen or deformed," Goto said.

He also said that the positive electrode of Cell 3 was found to have experienced particularly severe damage, and wiring inside some cells melted.
 
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  • #41
The problem is, they are doing the CT scans etc after a lot of secondary damage occurred. The hard part is figuring out what was the primary cause.

To use a different example, this
qantas-a380-engine-failur-006.jpg

looks impressive, but was not very relevant to the investigation compared with looking at what actually broke (or half of it, to be pedantic):
http://www.smarteraircharter.com/news/wp-content/uploads/2010/11/qantas-a380-engine-failure-part-300x225.jpg

After painstakingly dissecting a number of batteries, examining associated electronic parts, and analyzing information from flight-data recorders, NTSB experts and their Japanese counterparts haven't been able to pinpoint any specific component, automated subsystem or software application that appears to offer hope of finding answers.
... from http://online.wsj.com/article/SB10001424127887324761004578284392368343774.html

Having apparently got nowhere after a month of ground testing, Boeing have asked the FAA to approve some 787 flight tests to try to diagnose the problem. Flgiht testing to certify a fix is one thing. Flgiht testing to reproduce an on-board fire hazard is something else. I wonder that the FAA will make of the request :eek:
 
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  • #42
AlephZero said:
The problem is, they are doing the CT scans etc after a lot of secondary damage occurred. The hard part is figuring out what was the primary cause.

The failure modes in these cases seem almost identical, a chemically driven positive temperature feedback loop that once started seems to be impossible to stop by all present electronic control measures and so far there seems to be little data on the precursors that start it from all the monitoring data on the system. That leads me to believe the problem is related to what Elon Musk describes (large cells in close contact, thermal and/or electromagnetic effects).

"They [Boeing] believe they have this under control, although I think there is a fundamental safety issue with the architecture of a pack with large cells," writes Musk in an email. "It is much harder to maintain an even temperature in a large cell, as the distance from the center of the cell to the edge is much greater, which increases the risk of thermal runaway."
 
  • #43
A (lack of) progress report from the NTSB investigation: http://www.bbc.co.uk/news/business-21373593
I guess somebody in Boeing is saying "ouch", after those comments.

Re the "test flights", The FAA has granted Boeing permisson for one flight to return a 787 from a "paint job" in Texas back to Everett (i.e. not a test flight as such, though there are conditions imposed on monitoring the batteries while in flight).

Other news: the Europoean air safety agency (EASA) has been invited to join the US investigations. And Polish airline LOT, which has a 787 grounded in Chicago, is applying to the FAA via the EASA, for permission to fly it back home (presumably the fuel cost is less than the long term parking charges!)
 
  • #45
The person I consider to have the best investigative performance to date on this issue is Celina Mikolajczak.

Lithium-Ion Batteries Hazard and Use Assessment
Final Report Prepared by:
Celina Mikolajczak, PE
Michael Kahn, PhD
Kevin White, PhD
Richard Thomas Long, PE
Exponent Failure Analysis Associates, Inc.
© July 2011 Fire Protection Research Foundation
http://www.nfpa.org/assets/files/PDF/Research/RFLithiumIonBatteriesHazard.pdf

I will be glad to provide my opinions on what is contained in this rather damning document, but I am most interested in yours. It is clear to me that this technology is not mature enough in manufacture to be allowed in commercial aircraft. The absolute inability to identify point shorts and dendrite growth, or to prevent Li plating on the anode, the concerns with aging increasing liklihood of shorting, the acceptance of flammable electrolyte, the outgassing of flammable gas and the impossibility of extinguishing electrolyte fires with halon, the cascading effects of thermal runaway events and the inadequate "solution" of boxing this ticking timebomb of a battery in a titanium box vented to the slipstream screams not just of engineering incompetence but of another political mandate gone sour. I do not know if that last bit is true, but I do see Steven Chu scrambling for the exit as Airbus reconsiders Li-Ion deployment.

A kludge (or kluge) is a workaround, a quick-and-dirty solution, a clumsy, inelegant, difficult to extend, hard to maintain yet effective and quick solution to a problem, and a rough synonym to the terms "jury rig", "Jugaad" or "jerry rig". -- Wikipedia

Photos of Japan Airlines January 7 incident, battery pack and cell damage
-- Slide #13: NOTE THE SHORTING DAMAGE THROUGH THE TITANIUM CONTAINMENT! The failure of NTSB's mandated kludge may have been the strongest reason to ground the B-787 fleet. (The melting point of titanium is 3000 F.)
NTSB PDF February 7, 2013
http://www.ntsb.gov/investigations/2013/boeing_787/JAL_B-787_2-7-13.pdf
 
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  • #46
Thanks Ptero i forwarded that nfpa paper to a friend at Boeing.

Disasters are always a string of small things stacked up, they topple like Dominoes. That was Ernie Gann's premise in "Fate is the Hunter".
I saw same principle at work in nuclear industry.

In my opinion that is a significant domino.
 
  • #47
What's this? No one has quoted wiki yet?

Groundings
wiki said:
The focus of the review will be on the safety of the lithium-ion batteries made of lithium cobalt oxide (LiCo). The 787 battery contract was signed in 2005,[195] when LiCo batteries were the only type of lithium aerospace battery available, but since then newer and safer[299] types (such as LiFePO), which provide less reaction energy during thermal runaway, have become available.[193][300] FAA approved a 787 battery in 2007 with nine "special conditions".[301][302] A battery approved by FAA (through Mobile Power Solutions) was made by Rose Electronics using Kokam cells;[303] the batteries installed in the 787 are made by Yuasa[191].
bolding mine

Interesting. But I understand how contracts go. Something better comes along, but we've signed a contract to buy the inherently more dangerous battery.

I changed one of the reference links[193 original ref link], as the original was in some incomprehensible language(Norsk I think). My link points to the following image:

http://www.tu.no/incoming/2013/01/16/1200013182.jpg/ALTERNATES/w620f/1200013182.jpg

hmmm... What was the name of that guy who was so enthralled with LiFePO batteries, that he lost a small fortune investing in a company that made them? What was his name?

:rolleyes:

----------------------------
Ok to delete, as I am aware that I'm being a, "told you so", kind of smart***
 
Last edited by a moderator:
  • #48
That last page of the NFPA paper says it is a literature survey about transportation and storage of Li batteries, not about their actual use.

This may be more relevant in showing how faults develop can during use - e.g Fig 5 showing that heat release was delayed for 20 hours after the simulated fault was created.
http://www.evdl.org/docs/li_fault_detection.pdf

If something "goes bang" when you poke it with a sharp stick, there's a fair chance you will speculate there could be a cause and effect mechanism. If it goes bang a day later, for no apparent reason, that's not so easy to understand.
 
  • #49
AlephZero said:
That last page of the NFPA paper says it is a literature survey about transportation and storage of Li batteries, not about their actual use.

This may be more relevant in showing how faults develop can during use - e.g Fig 5 showing that heat release was delayed for 20 hours after the simulated fault was created.
http://www.evdl.org/docs/li_fault_detection.pdf

If something "goes bang" when you poke it with a sharp stick, there's a fair chance you will speculate there could be a cause and effect mechanism. If it goes bang a day later, for no apparent reason, that's not so easy to understand.

TLDR. But yes, bang, is not a pleasant sound.

Dec 8, 2011
General Motors Co. (GM), maker of the Chevrolet Volt plug-in hybrid that is the subject of a federal safety probe, is moving to a less volatile battery chemistry for its Chevy Spark electric car going on sale in 2013.
GM is using phosphate-based lithium ion batteries from Waltham, Massachusetts-based A123 Systems Inc. (AONE) that are less likely to burn than other lithium chemistry, including that used in the Volt model introduced last year, said battery experts and suppliers.

:cry:

Not that their manganese based LIOH battery was that bad. Didn't that Volt catch fire 2 weeks after it had been crash tested?
 
  • #50
OmCheeto said:
Not that their manganese based LIOH battery was that bad. Didn't that Volt catch fire 2 weeks after it had been crash tested?

At which point, one of my engineering mentors would repeat his favorite "development engineering is hard" parable:

Ug the caveman set off to the woods to pick some nuts and berries, but found the path blocked by a large dinosaur, asleep in the sun.

Shouting at the dinosaur had no effect, so Ug went back to his cave, found a sharp stick, and poked the dinosaur in the posterior.

Nothing happened for a couple of hours. Then, the dinosaur got up, took two steps backwards, and sat down on top of Ug, crushing him to death.

Now, the moral of this story is this: the dinosaur did not attack Ug because of the poke from the sharp stick. It was actually responding to a tap on the nose that somebody had given it three weeks earlier.
 

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