ComeAndGo
Posts: 815
Joined: Thu Mar 31, 2005 5:58 pm

RE: FAA Grounds 787 Part 6

Tue Jan 29, 2013 9:57 pm

Quoting Aesma (Reply 144):
You could make it an aluminum box with some fins in the direction that is clear of obstacles, it would help dissipate the heat of potential leaks.

Or make it out of expandable kevlar. So when the battery blows the container just expands rather then rupture.
 
ComeAndGo
Posts: 815
Joined: Thu Mar 31, 2005 5:58 pm

RE: FAA Grounds 787 Part 6

Tue Jan 29, 2013 10:04 pm

Quoting BEG2IAH (Reply 127):
It has been mentioned 50+ times in these threads that thermal runaway results in release of gasses and many posters want to have the battery sealed so nothing leaks. Gasses build pressure if they are produced in a sealed pressure vessel and eventually if vessel fails you have an explosion. Volume of electrolyte has nothing to do with pressures built by thermal runaway. How hard can it be to understand this?

because in other Li-Ion battery failures the battery did not explode but rather became so hot that it started combusting adjacent material.
 
SonomaFlyer
Posts: 2216
Joined: Tue Apr 20, 2010 2:47 pm

RE: FAA Grounds 787 Part 6

Tue Jan 29, 2013 10:46 pm

The containment box has to be made from a material which will not chemically react with the battery electrolyte nor catch fire itself.

Aluminium isn't the best material for the job. Steel is one possibility and there are others which can perform the containment function.
 
justloveplanes
Posts: 1014
Joined: Thu Jul 08, 2004 5:38 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 12:24 am

Quoting SonomaFlyer (Reply 152):
Steel is one possibility and there are others which can perform the containment function.

Extensive use of fins for heat transfer to can direct high temperatures away from other surfaces also.
 
rcair1
Posts: 1147
Joined: Wed Oct 28, 2009 8:39 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 12:57 am

(5) No corrosive fluids or gases that may escape from any lithium ion battery may damage surrounding structure or any adjacent systems, equipment, or electrical wiring of the airplane in such a way as to cause a major or more severe failure condition

Quoting RickNRoll (Reply 130):
It doesn't say "fluids or gases that may escape", it says "NO corrosive fluids or liquids that may escape", there is a big negative at the start of that sentence. So I asked, in his terms, does that mean that they have changed their minds, since their statement clearly indicates that corrosive fluids or liquids that have escaped are an issue for them.


If the word "that" was not in the sentence, your interpretation would be correct.
But it is not correct, because "that" is there.

Maybe it is easier if you pull out the subject and break it into phrases.

No corrosive fluids or gases that may escape from any lithium ion battery.....
[nothing that escapes]

may damage surrounding structure or any adjacent systems, equipment, or electrical wiring of the airplane ....
[may damage stuff around it]

in such a way as to cause a major or more severe failure condition,
[in a bad way]

"Nothing that escapes may damage stuff around it in a bad way."

If stuff does escape - but does not damage anything around it
... you are okay
If stuff does escape - and damages stuff around it,
... but does not damage it in way that make the airplane go bad
... you are okay.

Making a mark, making a stain, such-n-stuff - is allowed.

Maybe item 5 needs to be re-written - and it may as a result of this - but that is the way it is written.

(I can't believe I'm still doing this....)
rcair1
 
JoeCanuck
Posts: 4704
Joined: Mon Dec 19, 2005 3:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 1:07 am

Quoting justloveplanes (Reply 132):
NiMH does sound interesting. Obviously seems more stable than LiIon? Less prone to runaway? Same current delivery (Per Ah reserve) and recharge cycle capable? Re: you said slightly heavier that NiCad, on what basis? lb/Amp-hour?

Right...lb/amp hour.

Quoting justloveplanes (Reply 132):
Design questions, why use NiCads instead of NiMh on the 748? Certification?

NiMh may not be certified and NiCd's are tried and true...it's hard to beat something that just works, doesn't cause any drama when it doesn't work and creates no safety concerns.

Quoting justloveplanes (Reply 132):
Why else would NiMh/NiCad not work in the 787 if you are willing to live with the weight penalty? What would the weight difference be for similar current delivery and Ah reserve of these chemistries vs Li-Ion?

NiCd would work...but they have never been certified for the 787.

Quoting prebennorholm (Reply 134):
NiMH has higher capacity than NiCad. But unfortunately NiMH has by far the highest internal resistance when cold of all relevant battery types, including Lead-acid.

This is true...something I failed to take into account, but NiMh batteries are getting better.

Quoting strfyr51 (Reply 140):
Everybody is going on and ON about the Lithium-Ion Batteries and their safety, But NOBODY seems to question the Manufacturer OF said batteries and whether THEY had any culpability in their Manufacturing process According to Aviation Week 21Jan,2013, GS YASA of Japan was the manufacturer.

I have read quite a bit about the maker of the batteries being investigated.

Quoting max999 (Reply 145):
I'm appalled and angry that some people on here have suggested that the 787 was grounded prematurely

I don't recall reading any opinions that suggest the 787 shouldn't have been grounded.

Quoting SonomaFlyer (Reply 152):
Aluminium isn't the best material for the job. Steel is one possibility and there are others which can perform the containment function.

Some composites can take very high temperatures, as can some silicone compounds....but it's hard to beat the reliability and predictability of steel.

I believe the black boxes are still made of steel.
What the...?
 
cornutt
Posts: 333
Joined: Sun Jan 20, 2013 6:57 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 1:25 am

Soooo... any news today? I haven't seen any.
 
BEG2IAH
Posts: 940
Joined: Thu Apr 22, 2004 3:42 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 1:27 am

Quoting ComeAndGo (Reply 150):
Or make it out of expandable kevlar. So when the battery blows the container just expands rather then rupture.

So after all this discussion you are suggesting that battery should be sealed and you expect FAA to certify a bomb to be used on an aircraft? Interesting...

Quoting ComeAndGo (Reply 150):
because in other Li-Ion battery failures the battery did not explode but rather became so hot that it started combusting adjacent material.

Could you please provide an example of a battery the size of what's on B787 that was sealed and went into a thermal runaway. Laptop battery doesn't count.
Flying at the cruising altitude is (mostly) boring. I wish all flights were nothing but endless take offs and landings every 10 minutes or so.
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 1:45 am

Quoting ComeAndGo (Reply 150):
Or make it out of expandable kevlar. So when the battery blows the container just expands rather then rupture.

There are two potential problems there...unless you're very clever with the Kevlar design, it would be really hard to guarantee the expanding case doesn't run into something around it. And Kevlar doesn't do heat very well.

Quoting ComeAndGo (Reply 151):
because in other Li-Ion battery failures the battery did not explode but rather became so hot that it started combusting adjacent material.

The batteries didn't explode because normal batteries vent, they don't remain sealed when pressure starts to build.

Quoting JoeCanuck (Reply 155):
Quoting max999 (Reply 145):
I'm appalled and angry that some people on here have suggested that the 787 was grounded prematurely

I don't recall reading any opinions that suggest the 787 shouldn't have been grounded.

In max999's defense, the suggestion got made, although I can't find the post so it's either buried somewhere or the post got deleted.

Tom.
 
spacecadet
Posts: 3536
Joined: Thu Sep 20, 2001 3:36 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 1:59 am

Here's a wrinkle that I personally haven't seen talked about, and I believe I have been following these threads I thought pretty closely:

Elon Musk recommends smaller cells, and more space between them

The Verge has a sensationalist headline (obviously) but the real story here is that Elon Musk, who designs electric cars with lithium ion batteries for a living, says a simple change to more and smaller cells with more space in between would go a long way towards solving this problem. The real problem with the 787 battery, he says, is that the cells are so large and so close together than if one goes, all of them go in a domino effect due to the amount of energy contained in each cell and the ease of transferring that energy from one cell to the next. Smaller cells spaced further apart would fix that.

What say you, engineers?
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!
 
packsonflight
Posts: 384
Joined: Tue Jan 12, 2010 2:55 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 2:09 am

Quoting ComeAndGo (Reply 150):
Or make it out of expandable kevlar. So when the battery blows the container just expands rather then rupture.

All the solution that require any change or modification of equipment, that needs to be re certified, like a different battery, new charger or a new or different container take a lot of time, possibly up to 6 months. So there will be no quick fix that require any change of equipment. In case Boeing can not get the 787 in the air again without doing that I would expect broader redesign of the system

The quick fix would be like Tom says that Boeing demonstrates that the aircraft is safe possibly with some changes to operating and maintainance procedures, but I guess that is unthinkable until NTSB has come up with the cause for those two battery fires
 
tdscanuck
Posts: 8572
Joined: Wed Jan 11, 2006 7:25 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 2:15 am

Quoting spacecadet (Reply 159):
Smaller cells spaced further apart would fix that.

What say you, engineers?

I'm not sure how that makes the NTSB happy...their current angle seems to be that it's simply unacceptable for the battery to catch fire. Having only one cell melt down, rather than all of them, has implications for containment and damage to other systems but one cell going up in smoke still kills the battery and is still a battery fire.

Quoting packsonflight (Reply 160):
All the solution that require any change or modification of equipment, that needs to be re certified, like a different battery, new charger or a new or different container take a lot of time, possibly up to 6 months.

6 months would be a pretty hefty design change...with the scrutiny involved, the media circus, and the amount of people that Boeing, the FAA, EASA, JCAB, the suppliers, and the NTSB are all throwing at the problem, I would expect this one to move (properly) through the process at the head of the line.

Tom.
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 3:14 am

Boeing knew of problems with the 787 batteries, ANA changed 10 batteries between May and December 2012

http://www.nytimes.com/2013/01/30/bu...re-the-fires.html?hp&_r=1&

Quote:
Even before two battery failures led to the grounding of all Boeing 787 jets this month, the lithium-ion batteries used on the aircraft had experienced multiple problems that raised questions about their reliability.

Officials at All Nippon Airways, the jets’ biggest operator, said in an interview on Tuesday that it had replaced 10 of the batteries in the months before fire and smoke in two cases caused regulators around the world to ground the jets.

The airline said it told Boeing of the replacements as they occurred but was not required to report them to safety regulators because no flights were canceled. National Transportation Safety Board officials said Tuesday that the battery replacements were now part of their inquiry.

This fills in a few more blanks that have been speculated about, yes there were widespread issues with the 787 batteries, no the safety authorities were no informed and now that they kmow about it they are adding it to the investigation. The article also includes this gem

Quote:
In a little-noticed test in 2010, the F.A.A. found that the kind of lithium-ion chemistry that Boeing planned to use — lithium cobalt — was the most flammable of several possible types. The test found that that type of battery provided the most power, but could also overheat more quickly.


[Edited 2013-01-29 19:24:41]
BV
 
Shenzhen
Posts: 1666
Joined: Wed Jun 25, 2003 12:11 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 3:38 am

Quoting BoeingVista (Reply 162):
This fills in a few more blanks that have been speculated about, yes there were widespread issues with the 787 batteries, no the safety authorities were no informed and now that they kmow about it they are adding it to the investigation. The article also includes this gem

ANA having replaced 10 batteries doesn't (in my opinion) mean there is widespread issues with the 787 batteries. What it does say is that 10 batteries were replaced across xx airplanes, probably because they had a low charge. This could be caused by someone leaving the battery on, a faulty charger, a faulty battery (might just be its time) and so forth.

Cheers

[Edited 2013-01-29 19:53:35]
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 3:57 am

Quoting Shenzhen (Reply 163):
ANA having replaced 10 batteries doesn't (in my opinion) mean there is widespread issues with the 787 batteries. What it does say is that 10 batteries were replaced across xx airplanes, probably because they had a low charge. This could be caused by someone leaving the battery on, a faulty charger, a faulty battery and so forth.

10 batteries and chargers were replaced over a fleet of 17 aircraft and you don't think this is significant? But of course when these batteries were beginning to be replaced ANA's fleet would have been about 5.

At least 5 replaced for a low charge condition, low charge being a known failure mode that can lead to thermal runaway? And in fact a low charge fault was reported in the 787 that DID suffer a thermal runaway and was forced to make an emergency landing. No wonder the FAA is spooked theses issues seem to be much more widespread that we imagined.

[Edited 2013-01-29 19:58:56]
BV
 
phxa340
Posts: 1072
Joined: Thu Mar 29, 2012 4:07 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 4:06 am

Quoting BoeingVista (Reply 164):

If you didn't cherry pick the article to fit your agenda is also mentions Boeing and ANA didn't report the battery changes because they were a reliability concern NOT a safety concern. If anything - it proves that the safeguards Boeing installed were highly successful with the two notable exceptions being the JL and NH birds recently.
 
JoeCanuck
Posts: 4704
Joined: Mon Dec 19, 2005 3:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 4:09 am

Quoting tdscanuck (Reply 158):
In max999's defense, the suggestion got made, although I can't find the post so it's either buried somewhere or the post got deleted.

Ah...I must have missed it. Thanks. Still...the vast majority of posters seem to agree with the grounding...if little else.
What the...?
 
Shenzhen
Posts: 1666
Joined: Wed Jun 25, 2003 12:11 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 4:13 am

Quoting BoeingVista (Reply 164):
10 batteries and chargers were replaced over a fleet of 17 aircraft and you don't think this is significant? But of course when these batteries were beginning to be replaced ANA's fleet would have been about 5.

At least 5 replaced for a low charge condition, low charge being a known failure mode that can lead to thermal runaway? And in fact a low charge fault was reported in the 787 that DID suffer a thermal runaway and was forced to make an emergency landing. No wonder the FAA is spooked theses issues seem to be much more widespread that we imagined.

How old is the battery on a phone before they start seeing a little less performance and lower voltage. I wonder what the expected "on wing" time for a battery is today. If 12 months, then some could have been scheduled for replacement.

When a cell (inside the battery) dies and you lose 4 volts, you will see a lower voltage.
 
Shenzhen
Posts: 1666
Joined: Wed Jun 25, 2003 12:11 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 4:44 am

Quoting Shenzhen (Reply 167):
10 batteries and chargers were replaced over a fleet of 17 aircraft and you don't think this is significant? But of course when these batteries were beginning to be replaced ANA's fleet would have been about 5.

At least 5 replaced for a low charge condition, low charge being a known failure mode that can lead to thermal runaway? And in fact a low charge fault was reported in the 787 that DID suffer a thermal runaway and was forced to make an emergency landing. No wonder the FAA is spooked theses issues seem to be much more widespread that we imagined.

How old is the battery on a phone before they start seeing a little less performance and lower voltage. I wonder what the expected "on wing" time for a battery is today. If 12 months, then some could have been scheduled for replacement.

When a cell (inside the battery) dies and you lose 4 volts, you will see a lower voltage.

I used google to see if the MRBR is available on the internet. It wasn't, but did find the report for the 767. For the battery, this is what is required....

24-006 24-31-01 9 RS 2000 HRS ALL ALL RESTORE THE MAIN BATTERY (OFF-AIRCRAFT).

At 2000 hours, the main battery must be removed from the airplane and overhauled/restored. If the ANA airplanes flew 10 hours a day.........

The APU battery has the same requirement.

I guess my point is that no battery stays on an airplane very long, and if there was reliability issues with the battery, one would expect an airline to modify the hours allowed on wing, within their own maintenance program, to preclude un-scheduled maintenance which can equal delays / cancellations.

Cheers

[Edited 2013-01-29 21:20:00]
 
flood
Posts: 1045
Joined: Sat Feb 14, 2009 7:05 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 4:55 am

"At least 100 batteries failed on Boeing 787"
http://seattletimes.com/html/busines...020241385_787deadbatteriesxml.html

The Times also ran an article on Cessna's new battery:

"A video shows what happened when engineers disabled all the battery’s protective systems, overcharged it and then deliberately ignited the hot chemicals: Nothing more than a few wisps of smoke puffed out of the battery box."

The battery has roughly half the Ah rating, but it makes for a rather interesting comparison nonetheless:
http://www.eaglepicher.com/images/Li...hate%20Explosion%20Containment.avi

Full article:
http://seattletimes.com/html/busines...7battery29xml.html?prmid=head_main
 
spacecadet
Posts: 3536
Joined: Thu Sep 20, 2001 3:36 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:16 am

Quoting tdscanuck (Reply 161):
I'm not sure how that makes the NTSB happy...their current angle seems to be that it's simply unacceptable for the battery to catch fire.

Well, let's go back to the discussion on what constitutes "fire". If you strengthen containment, improve cooling, make the cells smaller and space them further apart, then what do you have if you get thermal runaway in one cell? Let's say instead of 8 cells you have 64, so each cell is 1/8 the size of a current cell. And you design it such that the failure of any one cell will be contained, and will not affect any of the other cells. Even if one cell fails, would that result in a "fire" or simply a momentary (and small) release of thermal energy?

Quoting phxa340 (Reply 165):
If anything - it proves that the safeguards Boeing installed were highly successful with the two notable exceptions being the JL and NH birds recently.

(spit-take) You're talking about 2 failures out of 24 planes in these two fleets. This is an 8.3% failure rate in the span of a week. This is not proof that safeguards were successful.

And that's discounting the other issues coming to light, which were "reliability" issues that nevertheless obviously could have (and did) become "safety" issues.
I'm tired of being a wanna-be league bowler. I wanna be a league bowler!
 
rheinwaldner
Posts: 1849
Joined: Wed Jan 02, 2008 4:58 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:19 am

Quoting spacecadet (Reply 159):

The Verge has a sensationalist headline (obviously) but the real story here is that Elon Musk, who designs electric cars with lithium ion batteries for a living, says a simple change to more and smaller cells with more space in between would go a long way towards solving this problem. The real problem with the 787 battery, he says, is that the cells are so large and so close together than if one goes, all of them go in a domino effect due to the amount of energy contained in each cell and the ease of transferring that energy from one cell to the next. Smaller cells spaced further apart would fix that.

What say you, engineers?

I agree. I have said it many threads ago already.

Quoting tdscanuck (Reply 161):
I'm not sure how that makes the NTSB happy...their current angle seems to be that it's simply unacceptable for the battery to catch fire.

That has been required right from the start and I still think it is realisticly doable.

But I also think that because of the size of a single cell, dynamic intra-cell effects could start developping, where parts of a cell start to runaway, just because its dimension is so widespread. In a sense we could no longer speak from homogenous single cells, but from independetly behaving, different zones, that are only monitored as a total....
Many things are difficult, all things are possible!
 
RickNRoll
Posts: 1855
Joined: Fri Jan 06, 2012 9:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:36 am

Quoting flood (Reply 169):

Sounds like the existing (necessary) safe guards for the LiIo batteries are so restrictive that they render any advantages not worth the trouble in practice.
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:36 am

Quoting phxa340 (Reply 165):
If you didn't cherry pick the article to fit your agenda is also mentions Boeing and ANA didn't report the battery changes because they were a reliability concern NOT a safety concern. If anything - it proves that the safeguards Boeing installed were highly successful with the two notable exceptions being the JL and NH birds recently.

The Seattle Times article says 100 - 150 batteries failed fleet wide, I don't see how Boeing can have 100 plus Li-ion batteries plus multiple fail knowing that failed Li-ion batteries can cause fires, on a fleet of under 50 aircraft and not consider this a safety issue. If they did not see this as a safety issue then all the better that this is now being looked at by the FAA and NTSB as it clearly DID turn out to be a safety issue.
BV
 
RickNRoll
Posts: 1855
Joined: Fri Jan 06, 2012 9:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:42 am

A lot of them havn't failed, if they just get to 15% capacity they lock themselves out, and have to be returned to the manufactuer to be reset and recharged safely. It appears that the battery demands of a plane on the ground will drain them more than anticicpated.
 
AeroWesty
Posts: 19551
Joined: Sat Oct 30, 2004 7:37 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 5:43 am

Quoting BoeingVista (Reply 173):
I don't see how Boeing can have 100 plus Li-ion batteries plus multiple fail knowing that failed Li-ion batteries can cause fires, on a fleet of under 50 aircraft and not consider this a safety issue.

Because you have to actually read the article rather than react to its title:

-----

"Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated

...

These problems seem separate from the two more significant incidents, when a battery caught fire on the ground in Boston and another smoldered in mid-air in Japan forcing an emergency landing

...

A second source with indirect knowledge of the progam confirmed multiple battery problems.

And another source said that additional problems included batteries that had failed because airline mechanics had improperly disconnected them, which trips one of the protection features and renders the battery unusable.

Other batteries were returned because they had exceeded their expiration date, the third source said."


-----

It isn't as if 100 batteries were imminent threats to aviation safety on their own.
International Homo of Mystery
 
JoeCanuck
Posts: 4704
Joined: Mon Dec 19, 2005 3:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:03 am

Quoting flood (Reply 169):

The battery in the video is a Lithium Iron Phosphate battery...a chemically different battery than the ones found on the 787. It reacts differently to over/under charging, over/under voltage conditions, heat and impact. What contains one type might not contain the other.

As well, the smoke came from the battery containment so there is not necessarily anything preventing electrolyte from escaping those same vents.
What the...?
 
wjcandee
Posts: 8317
Joined: Mon Jun 05, 2000 12:50 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:05 am

Quoting RickNRoll (Reply 174):

A lot of them havn't failed, if they just get to 15% capacity they lock themselves out, and have to be returned to the manufactuer to be reset and recharged safely. It appears that the battery demands of a plane on the ground will drain them more than anticicpated.

Not necessarily, given that the article says that some ran down or locked out because mechanics incorrectly disconnected them.

Sounds like this may be in part a user problem.

And sometimes the problem is so deeply ingrained in the culture of the operation that nobody notices the real cause?

Remember when they were about to ground the L1011 because numerous Eastern Air Lines flight attendants (but not passengers) were experiencing skin reddening around their necks after flights? That flight attendants were refusing to fly on the plane because of the "danger"? How the media hysterically talked about the "danger"? Does anyone besides me recall what turned out to be the problem?
 
AeroWesty
Posts: 19551
Joined: Sat Oct 30, 2004 7:37 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:07 am

Quoting wjcandee (Reply 177):
Does anyone besides me recall what turned out to be the problem?

Ink from the life vest demos, IIRC.
International Homo of Mystery
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:08 am

Quoting AeroWesty (Reply 175):
It isn't as if 100 batteries were imminent threats to aviation safety on their own.

At least 2 batteries clearly were, and these were not amongst the 100 returned. How many more?

You know, I believe thats some people only believe a safety threat exists once it has happened and we are standing around looking at a smoking hole in the ground.

You prevent deaths by investigating unexpected failures and if 100 failed 40kg Li-ion batteries on an aircraft doesn't ring alarm bells knowing the power that they can unleash when they go bad then you are in the wrong business.
BV
 
AeroWesty
Posts: 19551
Joined: Sat Oct 30, 2004 7:37 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:15 am

Quoting BoeingVista (Reply 179):
You prevent deaths by investigating unexpected failures and if 100 failed 40kg Li-ion batteries on an aircraft doesn't ring alarm bells knowing the power that they can unleash when they go bad then you are in the wrong business.

What would be accomplished looking for a fire threat when the reason for their return was "battery disconnected improperly" or "battery allowed to run down below spec", or "battery past expiration date"? How are those situations threats to aviation safety as standalone incidents?
International Homo of Mystery
 
User avatar
7BOEING7
Posts: 3039
Joined: Fri Oct 12, 2012 5:28 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:18 am

Quoting BoeingVista (Reply 179):
You prevent deaths by investigating unexpected failures and if 100 failed 40kg Li-ion batteries on an aircraft doesn't ring alarm bells knowing the power that they can unleash when they go bad then you are in the wrong business.



"Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated"


Which part of this do you not understand??? Sounds like it's operator error combined with improper design specs -- expensive but not catastrophic.
 
JoeCanuck
Posts: 4704
Joined: Mon Dec 19, 2005 3:30 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:21 am

Quoting spacecadet (Reply 159):
The Verge has a sensationalist headline (obviously) but the real story here is that Elon Musk, who designs electric cars with lithium ion batteries for a living, says a simple change to more and smaller cells with more space in between would go a long way towards solving this problem. The real problem with the 787 battery, he says, is that the cells are so large and so close together than if one goes, all of them go in a domino effect due to the amount of energy contained in each cell and the ease of transferring that energy from one cell to the next. Smaller cells spaced further apart would fix that.

That, if it worked, wouldn't solve the certification problem since it would have to be tested and proven as much as any other design, and probably more than going to battery types already proven in airline service. Isolating cells still doesn't prevent any single cell from catching fire which is what the FAA is looking for. They want a 0% chance of any cell catching fire...ever...which may not be achievable since any battery of any type can catch fire but there are certainly safer types than the current ones.

I think Boeing will end up biting the bullet and replacing the batteries with something more chemically benign while more exotic batteries are being further tested.

Eventually, the hope is that investigators discover exactly what caused the fires, and that the causes were the same for both batteries, solutions identified, (including more robust containment), and this is one more problem permanently checked off of the 787 to-do list.

I still think permanent fixes will take longer than putting an interim solution in place and getting the planes flying.
What the...?
 
XT6Wagon
Posts: 2726
Joined: Tue Feb 13, 2007 4:06 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:32 am

Quoting BoeingVista (Reply 179):

At least 2 batteries clearly were, and these were not amongst the 100 returned. How many more?

and how many seat covers have been replaced in that time? ok thats a little silly..... so lets go for

How many tires? How many brakes?

Some things are "wear" items even if you don't think of them that way. Batteries are wear items. They wear out when used. They wear out when not used. ALL batteries mankind uses are this way. Well atleast all the ones worth using.
 
astuteman
Posts: 7075
Joined: Mon Jan 24, 2005 7:50 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:44 am

Quoting phxa340 (Reply 165):
If you didn't cherry pick the article to fit your agenda is also mentions Boeing and ANA didn't report the battery changes because they were a reliability concern NOT a safety concern. If anything - it proves that the safeguards Boeing installed were highly successful

Either that or it proves that ANA were not aware of the underlying safety issue...

Quoting 7BOEING7 (Reply 181):
Which part of this do you not understand??? Sounds like it's operator error combined with improper design specs -- expensive but not catastrophic.

In terms of the way a complex system fails, operator error combined with improper design specs could easily have the potential to be catastrophic IF the particular type of Li battery being used is one that is particularly prone to overheating problems under certain conditions, as LiCo batteries appear to be

Quoting BoeingVista (Reply 162):
In a little-noticed test in 2010, the F.A.A. found that the kind of lithium-ion chemistry that Boeing planned to use — lithium cobalt — was the most flammable of several possible types. The test found that that type of battery provided the most power, but could also overheat more quickly.

For me failures like this tend to have multiple causes, and the key will be to understand which parts of the "system" need to change

Quoting JoeCanuck (Reply 176):
The battery in the video is a Lithium Iron Phosphate battery...a chemically different battery than the ones found on the 787. It reacts differently to over/under charging, over/under voltage conditions, heat and impact. What contains one type might not contain the other.

I'm not sure how well recognised it is that there is more than one type of li ion battery.

I'm not sure how easy it would be to change the 787's batteries to Li Iron Phosphate, or whether that could contribute to a solution. But if it is more benign under "operator error or improper design spec" it might form part of a solution..

Rgds
 
FlyingAY
Posts: 416
Joined: Thu Jun 21, 2007 2:26 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 6:49 am

Quoting 7BOEING7 (Reply 181):
"Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated"

Which part of this do you not understand??? Sounds like it's operator error combined with improper design specs -- expensive but not catastrophic.

Considering the nature of a LiIon battery, I think the system should automatically try to prevent a situation where the battery gets too empty and must be replaced. Charge the battery automatically as needed, raise an alarm if the capacity gets low and cut off the power before a critically low charge is reached.

Are these replaced batteries all main batteries? I've understood the APU battery should see only a very limited amount of use. Why would they be run down so far that a low-voltage cutout gets activated? Remember that self discharge of LiIon is very small (just installed a battery manufactured 1,5 years ago that had more than 50% of the capacity left).

Quoting flood (Reply 169):
"At least 100 batteries failed on Boeing 787"
http://seattletimes.com/html/busines....html
Quoting SeattleTimes:
Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated.

At that stage, the batteries, which cost about $16,000 each, are essentially dead and cannot be recharged.

If most of the batteries had run down so far that the batteries are dead, why is there no mechanism that cuts the power before the battery is dead? It would seem like bad design to let the battery discharge that far that it is rendered unusable. Imagine having your cell phone battery changed everytime you forget to charge it before the battery is empty! This is most likely simplifying the thing too much, but so many battery failures on such a small fleet sounds suspicious. I'm sure we'll hear more in the nearby future.
 
User avatar
seahawk
Posts: 9224
Joined: Fri May 27, 2005 1:29 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 7:05 am

I would say it is not uncommon for a new technology to have some problems at the start. Although I must say it would have been interesting to know if Boeing had to report battery changes to the FAA during the test flight phase and if there have been any problems during that phase. If not it would point into the direction of user error by the airlines. I would also believe that those reported 100-150 battery changes were unscheduled changes, otherwise it would be a joke to even talk about them.
All involved parties must come clean quickly now, before the reputation of the Dreamliner, FAA and Boeing is damaged. The information management must improve. They need to put all battery system related problems (safety or reliability or whatever) on the table now.
 
flood
Posts: 1045
Joined: Sat Feb 14, 2009 7:05 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 7:09 am

Quoting JoeCanuck (Reply 176):
The battery in the video is a Lithium Iron Phosphate battery...a chemically different battery than the ones found on the 787. It reacts differently to over/under charging, over/under voltage conditions, heat and impact. What contains one type might not contain the other.

Yes, I should have been more descriptive, sorry. If I'm not mistaken the 787's batteries are cobalt-based whereas the A350's Saft battery is manganese. I just found the containment interesting and, in light of the previous comments surrounding armoring, wonder if such a design can't be upscaled to provide a better venting/containment solution for the 787's units.
 
ComeAndGo
Posts: 815
Joined: Thu Mar 31, 2005 5:58 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 7:34 am

Quoting phxa340 (Reply 165):
If you didn't cherry pick the article to fit your agenda is also mentions Boeing and ANA didn't report the battery changes because they were a reliability concern NOT a safety concern.

then why is this happening ?

Quoting BoeingVista (Reply 162):
National Transportation Safety Board officials said Tuesday that the battery replacements were now part of their inquiry.
 
FlyingAY
Posts: 416
Joined: Thu Jun 21, 2007 2:26 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 7:53 am

Quoting seahawk (Reply 186):
I would say it is not uncommon for a new technology to have some problems at the start.

LiIon batteries hardly are a new technology. Not even in an airplane.

Quoting ComeAndGo (Reply 188):
then why is this happening ?

Well, it could be that at the time when the batteries were changed it was not a safety concern. In the light of current events it very well could cause some concern.
 
User avatar
AirlineCritic
Posts: 1707
Joined: Sat Mar 14, 2009 1:07 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:09 am

The report about large number of batteries being returned is interesting. (If true, as always.)

Remember that the 787 had a very extensive flight testing program. Why are the battery problems coming up now, and not during flight testing? One theory is that operational practices and airport facilities are different. If I were Boeing, I would investigate the history behind each case. Not that I believe the returned batteries were about to burn - probably not. But it does seem like a high frequency of component maintenance events. Something is causing this. Maybe an operational error is causing batteries to work not optimally, and in some small percentage, even lead to batteries suffering so much that they have a risk of thermal run away. At least that would be an angle to look at.
 
ComeAndGo
Posts: 815
Joined: Thu Mar 31, 2005 5:58 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:20 am

it's very simple it's mentioned in the Seattle Times article. This battery will drain in less then one hour if used by ramp personal when servicing the aircraft with it's power off. So refueling or loading/unloading cargo from the aircraft. When the main aircraft power is off the battery supplies electricity for lights and other ramp related systems that ground personal will use to service the aircraft. Apparently this battery design allows for the battery to discharge in less than an hour with only minimal draw.
 
art
Posts: 3130
Joined: Tue Feb 08, 2005 11:46 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:23 am

The lithium ion batteries installed on the Boeing 787 are inherently unsafe, says Elon Musk, founder of SpaceX and owner of electric car maker Tesla.

"Unfortunately, the pack architecture supplied to Boeing is inherently unsafe," writes Musk in an email to Flightglobal.

"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," he adds.

Both Boeing and Tesla use batteries fueled by lithium cobalt oxide, which is among the most energy-dense and flammable chemistries of lithium-ion batteries on the market. While Boeing elected to use a battery with a grouping of eight large cells, Tesla's batteries contain thousands of smaller cells that are independently separated to prevent fire in a single cell from harming the surrounding ones.

http://www.flightglobal.com/news/art...ttery-fundamentally-unsafe-381627/
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:24 am

Quoting 7BOEING7 (Reply 181):
"Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated"


Which part of this do you not understand??? Sounds like it's operator error combined with improper design specs -- expensive but not catastrophic.

Most doesn't mean all, you seem to have trouble understanding that.

Quoting XT6Wagon (Reply 183):
and how many seat covers have been replaced in that time? ok thats a little silly..... so lets go for

Are seat covers at risk from spontaneous combustion? If they were I'd be interested in their replacement

Quoting XT6Wagon (Reply 183):


How many tires? How many brakes?

If this was above predicted wear and replacement this should also be investigated.

Quoting AeroWesty (Reply 180):

What would be accomplished looking for a fire threat when the reason for their return was "battery disconnected improperly" or "battery allowed to run down below spec", or "battery past expiration date"? How are those situations threats to aviation safety as standalone incidents?

Because under voltage conditions can be the precursor of thermal runaway. Li-ion batteries are clearly a fire threat you don't seem to accept the obvious.

This might be a good time to point out that the FAA has not rulled out under voltage as a cause of the 2 battery meltdown incidents.

Quoting astuteman (Reply 184):
For me failures like this tend to have multiple causes, and the key will be to understand which parts of the "system" need to change

Lord, a sensible response.. Yes, if you see a whole bunch of unpredicted failures you need to investigate without preconceptions and find the cause which could be anywhere in the system.
BV
 
AeroWesty
Posts: 19551
Joined: Sat Oct 30, 2004 7:37 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:40 am

Quoting BoeingVista (Reply 193):
Because under voltage conditions can be the precursor of thermal runaway. Li-ion batteries are clearly a fire threat you don't seem to accept the obvious.

Perhaps you can explain the obvious I'm missing then.

I accept that once a battery falls below a certain threshold while it's powering aircraft systems in lieu of another power source, the system renders it unusable. It gets replaced. It does not fly.

Correct me if I'm wrong, but what you seem to be suggesting is that if a battery would fall below this certain threshold during flight, the safety systems would allow the battery to be recharged, causing a thermal runaway. That's certainly a possibility which should be reviewed, I've no problem with that.

However, in my non-expert mind, I do believe that that scenario would be one expected, tested for, and safeties built around, so that a battery falling below spec while the other generators are idle wouldn't necessarily be viewed as an imminent threat to aviation safety as a standalone event.
International Homo of Mystery
 
Unflug
Posts: 728
Joined: Wed Jan 11, 2012 5:25 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:43 am

Quoting rcair1 (Reply 154):

(I can't believe I'm still doing this....)

Understandable  

But thanks anyway!
 
User avatar
JerseyFlyer
Posts: 1459
Joined: Fri May 25, 2007 7:24 pm

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:48 am

Quoting art (Reply 192):
While Boeing elected to use a battery with a grouping of eight large cells, Tesla's batteries contain thousands of smaller cells that are independently separated to prevent fire in a single cell from harming the surrounding ones.

Intuitively this makes sense. An explanation from Boeing for their choice of eight large cells when presumably they discounted options comprising larger numbers of smaller cells would be of interest.
 
sankaps
Posts: 1692
Joined: Fri Jan 04, 2008 6:51 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 8:58 am

Quoting tdscanuck (Reply 149):
Sure they can. For example:
"As a result of an in-flight, Boeing 787 battery incident earlier today in Japan, the FAA will issue an emergency airworthiness directive (AD) to address a potential battery fire risk in the 787 and require operators to temporarily cease operations.

The AD was to ground the aircraft. That is, as I said, the only logical option they have if they do not know the root cause of a recurring failure with potentially serious safety implications.

Quoting tdscanuck (Reply 149):
They had lots of choices...the AD could have imposed an operating limitation like "inspect the battery after every flight" or something like that.

That would be a fairly pointless AD since there is no evidence that we know of yet, that suggests inpsections after every flight would help.

The FAA did the right thing here, there really was no other acceptable option short of waiting to act until something catastrophic happened. And that, in today's safety climate, would simply be highly, perhaps even criminally negligent.
 
User avatar
BoeingVista
Posts: 2045
Joined: Mon Jan 12, 2009 9:54 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 9:11 am

Quoting AeroWesty (Reply 194):
Correct me if I'm wrong, but what you seem to be suggesting is that if a battery would fall below this certain threshold during flight, the safety systems would allow the battery to be recharged, causing a thermal runaway. That's certainly a possibility which should be reviewed, I've no problem with that.

Over discharge of a Li-ion battery can lead to it short circuiting and that can lead to thermal runaway, it does not need to be recharged to be potentially dangerous.

So under voltage can be as dangerous as over voltage.
BV
 
AeroWesty
Posts: 19551
Joined: Sat Oct 30, 2004 7:37 am

RE: FAA Grounds 787 Part 6

Wed Jan 30, 2013 9:23 am

Quoting BoeingVista (Reply 198):
Over discharge of a Li-ion battery can lead to it short circuiting and that can lead to thermal runaway, it does not need to be recharged to be potentially dangerous.

When you say "over discharge", is your meaning discharging too quickly or discharging below a certain value, or both?
International Homo of Mystery

Popular Searches On Airliners.net

Top Photos of Last:   24 Hours  •  48 Hours  •  7 Days  •  30 Days  •  180 Days  •  365 Days  •  All Time

Military Aircraft Every type from fighters to helicopters from air forces around the globe

Classic Airliners Props and jets from the good old days

Flight Decks Views from inside the cockpit

Aircraft Cabins Passenger cabin shots showing seat arrangements as well as cargo aircraft interior

Cargo Aircraft Pictures of great freighter aircraft

Government Aircraft Aircraft flying government officials

Helicopters Our large helicopter section. Both military and civil versions

Blimps / Airships Everything from the Goodyear blimp to the Zeppelin

Night Photos Beautiful shots taken while the sun is below the horizon

Accidents Accident, incident and crash related photos

Air to Air Photos taken by airborne photographers of airborne aircraft

Special Paint Schemes Aircraft painted in beautiful and original liveries

Airport Overviews Airport overviews from the air or ground

Tails and Winglets Tail and Winglet closeups with beautiful airline logos