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Japan Airlines Dreamliner catches fire in Boston

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posted on Jan, 11 2013 @ 06:20 PM
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reply to post by solidshot
 


I tend to think of problems with planes in three categories.

1. Oh #
2. Damn.
3. Meh

Most of the Dreamliner problems fall in the "damn" category, except for the JAL flight that had the fire. That falls in the first category. A cracked windshield, and brake issues are more "meh", because every plane out there will have them. A leaking generator is more serious, because it could cause a fire, but is still only worth a "damn".

The electrical panel issue is a concern, because to have multiple aircraft for different carriers have electrical problems points to either bad manufacturing, or a design issue. I'm leaning towards bad manufacturing, because of all the manufacturing problems they had in the initial build, and United saying they found a miswired panel.

I wouldn't be too worried though, as Boeing completed over 200,000 testing hours with the 787. If there was a serious design flaw, I would think there would have been some evidence of it during that portion of the program.
edit on 1/11/2013 by Zaphod58 because: (no reason given)




posted on Jan, 14 2013 @ 10:46 PM
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The NTSB has released pictures of the battery box after the fire.

www.flightglobal.com...



posted on Jan, 15 2013 @ 12:23 AM
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reply to post by Zaphod58
 


The bad thing here is, LiIon is considered to be pretty stable. It's TOUGH to screw up lithium ion.

Li-poly, that's brutal. Easy to set off. But most Li-Ion cells are hard to make fail quite THAT badly. We've designed Li-ion packs into military equipment with way over 100WH capacity that have never failed in any way (other than to auger them in intentionally when you need that last tiny bit of time). And by 'designed in', I mean we designed the battery manager, the pack, the charger, the whole thing.

I've gotten the cells to swell, to fail, to just quit working. With some physical abuse, you can get them to smoke. A nail can be exciting. But to blow a battery up like that is tough. Maybe they weren't rated for the vibration/impact they're being subjected to and it caused an internal physical short. Or maybe the charging circuit is badly designed. Really badly designed.

edit to add:

We did have to work with a piece of equipment with a big battery pack that was so mechanically sensitive, if you tossed it on the bench it would burst into flames. The thing had a bad mechanical design that allowed some metal parts inside to shift and contact two bare tabs on a connector. We put out a notice that in the event of abduction, you could consider popping the pack out and throwing it at your kidnappers as a value-added self defense system.
edit on 15-1-2013 by Bedlam because: (no reason given)



posted on Jan, 15 2013 @ 08:55 AM
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reply to post by Bedlam
 


Boeing designed all kinds of safeguards into them where one cell might overheat, or just fail, but they weren't supposed to do that. They tested them for like 100,000 hours and never had one catch fire like that. So there's going to be a big investigation by both the NTSB and Boeing to figure out why this one did that. It's possible that it had a defect in it that allowed it to catch fire.



posted on Jan, 24 2013 @ 03:16 PM
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There is evidence of a short circuit and thermal runaway in cell 5 of the APU battery. It's an 8 cell, 32v battery, located in the after electronics bay, and is used to start the APU on the aircraft. They have no idea why, or why the protection systems failed.

The timing of this failure, and the failure on the ANA flight were within 100 flight hours of service on both aircraft.

Pictures of the battery here



posted on Jan, 28 2013 @ 01:05 AM
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The joint US-Japanese investigation is now looking into Kanto Aircraft Instrument Co. They said the investigation into GS Yuasa was over, as there is no evidence that the problem was with the battery. Kanto Aircraft Instrument Co makes the systems that monitor voltage, charging, and temperature of the batteries.



posted on Jan, 28 2013 @ 02:33 AM
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The Japanese are all about HONOR.

Congress shouldn't have belittled the Toyota Exec in their Horse and Pony Show to publicly humiliate him.

Japan has the means to make the 787 DreamLiner look bad...which makes it's makers look bad. Which makes America look bad.


Congress shouldn't have belittled the Toyota Exec.. These are the repercussions aren't they?

Japan doesn't really like us over what we've done to them...making them the sole first buyers of the 787 Dreamliner wasn't a good idea was it?



posted on Jan, 28 2013 @ 07:22 AM
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Originally posted by Zaphod58
The joint US-Japanese investigation is now looking into Kanto Aircraft Instrument Co. They said the investigation into GS Yuasa was over, as there is no evidence that the problem was with the battery. Kanto Aircraft Instrument Co makes the systems that monitor voltage, charging, and temperature of the batteries.


I know who I'm glad I'm not.

It's radically easy to screw up the charging and maintenance systems of Lithium batteries. While it's easier to screw up poly, you can do Ion if you work at it hard enough. It's really pretty tough to get just right - there are all sorts of issues with cell balancing and coulomb counting accurately that just suck butt. And in an aircraft environment, it's also easy to have your crap lock up due to the notoriously bad power noise problems. All you have to do to slam dunk a pack is have your pack management micro lock up. One bad line of code, a cap you should have added, skimping on power conditioning, a FET that isn't rated quite right and pops a gate due to a power spike and down you go.

In addition, there are any number of "go by" designs that are promulgated for this that have all sorts of bugs in them you may not notice right away. We eventually scrapped the damned things and started from scratch.

It sort of sounds like a cell balance issue. As you charge and discharge a pack, if your cell balancing system doesn't work very well, you'll get some cells overcharging and some undercharging, if your pack manager doesn't deal with that by safing the pack (blowing the fuses) you will get thermal runaway just like this, only it won't happen right off, it'll save it for the field.



posted on Jan, 28 2013 @ 09:24 AM
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reply to post by Pervius
 


The only problem is that the Japanese are responsible for several critical components of the aircraft. So it doesn't just make Boeing look bad, it makes them look bad too if that's the cause of the problems.



posted on Jan, 28 2013 @ 09:57 AM
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reply to post by Bedlam
 




It sort of sounds like a cell balance issue.


Same problem you face converting your UPS to NIMH. If your charge managing circuit gets disconnected and you are using a large pack of individual cells the pack voltage may be a useless indicator. Thermal monitoring at the individual cell level would prevent pack fires but that *would* be a battery pack design issue.

NIMH can be safely float charged below .1C so it should work well for a UPS application.
V=IR so as the voltage head tapers the current drops below that level.

A 32V nominal rated adapter should be able to charge 24V NIMH cell packs by just adding a simple resistor in series.

I can't imagine a safe large capacity Li ion pack design that doesn't use thermal monitoring though?
There must be something else going on with this story?



posted on Jan, 28 2013 @ 05:44 PM
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reply to post by Bedlam
 




One bad line of code, a cap you should have added


One article I read said they were planning on using the power pack to spin up the engines, that requires a lot of amps.

EEStor released specs for their 24V-BDHD



DC output voltage: 24V +/- 0.5V Output current: 20A continuous
Output current transient: 80A for 2s
Output current protection: fast-opening fuse
Volume: 9..44 x 10^5 mm^3 (101.6 mm cubed)
Weight: 2.2kg Energy storage: 26.7 A-hrs
100% deep-cycle usage: 10^6
Charging time 0-100%: 90s Operating
temp range: -40*C to 49*C (includes fast charging)
Maximum storage temp: 150*C
Estimated price: $62.50 @ 50k/yr, $52.25 @ 500k/yr


At first I thought it must be a hybrid but 100% deep-cycle usage: 10^6!
Almost worth sneaking into area 51 to steal one.

They probably have a current limiting design that can't be reverse engineered into anything more dangerous.
There is that 1490 mesoshell stuff with a Singapore patent, so it might not be vaporware.

$62.50 is dirt cheap for those specs, currently it costs a lot more than that to use the bus..
edit on 28-1-2013 by Cauliflower because: (no reason given)



posted on Jan, 28 2013 @ 08:45 PM
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reply to post by Cauliflower
 


We got a RFQ from SOCOM once to do a battery pack that would have to have about 14kWh of storage, for running Zodiacs up a river. Way up a river. They were using a dozen diehards and having to ruck them in along with their gear.

The RFQ required too much energy density for even li-poly though. We never could find a cell tech at the time that would meet their goals, even the nano-material designs.

It was a ballsy request, though, and we could get close, but just not all the way. You had to be able to break the thing into chunks so everyone on the team could have a piece, and it had to work with some missing pieces in case someone didn't make it. The pieces had to be salt water immersible. And when it was assembled, it had to be chargeable from just about anything, THAT was a major issue. And you had to be able to assemble it, test it and hook it up kneeling in a half-flooded Zodiac in the dark under fire. Oh, and it had to be rifle proof - if it took a hit you could NOT burst into flames. Drop that brick out, ok, combust, no.



posted on Jan, 31 2013 @ 02:25 PM
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More interesting things coming out during the investigations. ANA says that they changed 10 batteries last year, for various reasons. They didn't inform investigators because they didn't compromise safety of the aircraft. JAL also says they changed batteries "on a few occasions". Five of the ANA batteries has "unusually low charges" when they were replaced.

AvWeek article

NTSB investigators have been to Kanto, and found nothing of significance. They tested the damaged circuit boards as best they could but found nothing. They are taking apart the remaining cells of the battery to examine them, but both examinations are coming up with a whole lot of nothing so far.

Other AvWeek article



posted on Feb, 4 2013 @ 05:24 PM
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Oh this is ungood for Boeing. They are revisiting whether Boeing met the FAA requirements for certifying the Li batteries. They said that 2 of the 9 special certifications allowed for exceptions to normal safety protocols under the "extremely remote" chance of a failure of the charging and monitoring system. Which has failed at least twice to date. Extremely rare means the odds of it happening are almost non-existent in the entire aircraft lifespan (meaning all operational aircraft built) and translates to about one in 10 million flights.

Source



posted on Feb, 5 2013 @ 05:18 PM
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Both the ANA and JAL batteries show signs of a short and thermal runaway. The ANA battery was in cells 3 and 6, with cell 6 showing a hold burned in the side of the cell, and a melted anode in 3. The JAL damage was contained to cell 5.

ETA: The JTSB has found damage to all 8 cells in the ANA battery, 3 and 6 were the most severely damaged though.
edit on 2/5/2013 by Zaphod58 because: (no reason given)



posted on Feb, 12 2013 @ 01:06 PM
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The NTSB is investigating whether dendrites built up on the batteries, causing a short circuit in them. Dendrites can built up inside an Li battery, through absorption of lithium ions, or foreign material and can touch both the positive and negative sides of the battery, causing a short.

AvWeek
edit on 2/12/2013 by Zaphod58 because: (no reason given)



posted on Feb, 12 2013 @ 01:07 PM
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So much for "green" technology

I guess its just not there yet!!!!



posted on Mar, 8 2013 @ 01:37 AM
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Interim report has been released on some of these battery fires.

www.ntsb.gov...
edit on 8-3-2013 by solidshot because: (no reason given)



posted on Mar, 8 2013 @ 09:54 PM
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Bad news for Boeing. The NTSB is going to hold hearings and a conference in April on the battery issue. So they'll stay on the ground longer than hoped.





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