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Wisdom
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 9:27 pm

Quoting kanban (Reply 1):

posted this just before cut off
Yuasa makes these batteries for many land surface operations, trains, trucks, etc. and seem to have no problems. Possibly could the problem be related to the pressure differentials when flying... ie water boils at a lower temperature at elevation, so could the organic fluid in these batteries "boil" at altitude and leave the anodes/cathodes bare and in contact?

It's unlikely.
Remember what the B787 is great for... it has barely any pressure differentials, since it maintains a very low cabin altitude of 5000ft at cruise.


For the reference, I will put it on the board again for all airliners.net users.

I have said it before and I will say it again, Li-ion batteries may be the cause if the manufacturer doesn't meet the Boeing specs. Japanese companies are known for their integrity and have nothing to gain from fooling around with li-ion batteries on an aircraft. They charge enormous amounts of money for these, so I don't see the point of getting greedy just to save a few more bucks on a battery of a few tons of dollars.

-Li-ion batteries don't "self-combust" in normal operations. They can get hot during use, but they are unlikely to see temperatures as high as their kindling point.
-Li-ion typically explode or catch fire if the overcharge protection fails but that's very different to "self combustion", given that the overcharge is created by the elements that charge it.

-A li-ion battery can be unstable if charged beyond its capacity and stored in that condition. A shock could then cause the battery to catch fire or explode.

-The liquid solution is flammable. Flammable means that if lit on fire, it will burn.
This is why one needs to be careful when transporting li-ion batteries on an aircraft. If a battery gets damaged and the liquid flows into an electrical assembly, it could be lit on fire.

However, the ion solution will not catch fire by itself. Like any fuel, it needs a source of ignition.

Also, it's unlikely for a battery's protections to fail. These are normally fail-safe protections, unless they put an override to prevent the battery from going to fail-safe in an emergency. However, I don't think that Boeing would put an override on that overrides the fail-safe in a charging mode.


So there could be 3 ways for this issue to happen.
-too high temperatures in the e-bays, not enough air circulation, causing the li-ion solution to reach the flash point or the unlikely kindling point. I don't deem this very likely but LRU computers have been prone to overheating in the past.

-interface problems with the rest of the electric architecture. For instance, remember that the B787 runs on wild frequency generators without a CSU. This requires conversions and stabilisations to provide a clean source of DC power. Lack of stability could send the li-ion haywire, which I believe is a very possible cause. Any irregularities could make li-ions cook. As such, this is the most probable, in my opinion.

-batteries are not meeting design, test specs or the design itself is flawed. Li-ions have been on board of aircraft for several years now and never caused this kind of damage.


The battery containment is the least important feature and is the protection of last resort.
Has it worked? Difficult to say.

If I look at the video's from the evacuation of the NH787, I see thick smoke coming from the front starboard side around the aircraft and black lines running from the side of the fuselage, from something that looks like drain ports. I'm not part of the engineers who has been trained on the 787, so I don't know if that's supposed to be there but it doesn't look right. It is said that the hot liquid poured its way on a 12 feet stretch.

However the fire didn't destroy the entire aircraft or maybe it didn't get chance. So it's impossible to say if the containment saved the day, but judging by the smoke, it didn't do that good a job.

Anyway, Airbus CEO says on the A350-XWB usage of li-ions:

“There are some architectural differences and the suppliers are different,” Bregier said. “As Boeing said, the battery is not the issue, it’s the way you integrate it to the power system.”

http://www.washingtonpost.com/busine...-11e2-bc4f-1f06fffb7acf_story.html

[Edited 2013-01-17 13:30:46]
 
chuchoteur
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 9:42 pm

Quoting Stitch (Reply 47):
Quoting PassedV1 (Reply 35):Correct me if i'm wrong, but my current understanding, which is mostly based on what I have read here on A. Net, is that the only advantage these batteries have to the current...proven technologies...is that they weigh less and have a smaller volume.
Those are two of the reasons. As I recall from the previous discussions, the power they supply is also more stable and they will hold a charge longer (as neither battery is required to provide constant power - the generators in the engines are the primary source of electrical power).

Another major aspect of Lithium ion batteries is that they do no suffer from memory effect. The performance and charge remains constant, it doesn't degrade over time after repeated charges. This is important for an aircraft that needs a reliable electrical source. As Stich mentions, it doesn't loose charge either.

Of course an alternative type of battery could be 2x heavier (so you'd lose out on 2 or 3 passengers in terms of weight!), it would also be significantly bigger. If you consider a 777, the battery is fairly small and it already requires a bit of a workout if you need to change it... accessibility/maintainability is quite an important point.

Quoting glideslope (Reply 51):
I believe Yuasa sub contracts the 787 Battery for production in France. Forgot the name of the French Co that makes them.

Thales manufacture the control electronics that manage the battery. I believe that the 787 batteries come with 4x independant electronic controllers (i.e. if three fail, you still can't overcharge the battery), so in theory it's extremely well protected and shouldn't be spiked by the electrical system feeding into it.
 
PHX787
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 9:53 pm

Quoting glideslope (Reply 51):
Quoting PHX787 (Reply 2):

Let me attempt to recap and correct me if I am wrong:

The 787 is grounded worldwide indefinitely due to battery issues which brought ANA ship 804 in TAK and lit JL ship 829 on fire in BOS. Anyone know if the MOT has probed Yuasa yet? There was some word going around my circles about it.

I believe Yuasa sub contracts the 787 Battery for production in France. Forgot the name of the French Co that makes them.


One of my contacts has an email to Yuasa but he's not certified to use it, and clearly neither am I...anyone here have any sort of journalism clearance?
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CALTECH
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:23 pm

Quoting PassedV1 (Reply 35):
Correct me if i'm wrong, but my current understanding, which is mostly based on what I have read here on A. Net, is that the only advantage these batteries have to the current...proven technologies...is that they weigh less and have a smaller volume.

Supposedly provide more power and at a stable level of power discharge.

Quoting PassedV1 (Reply 35):
Some of you on here are justifying the selection by saying "well the equivilant such and such battery would weight 300 more lbs or be so much bigger". Well, we are not talking about a Honda, 300lbs is not significant.

X 2 batteries which saves almost 500 lbs in weight. that is substantial, especially in a airplane. It is a very significant amount. Also, there are other Li-Ion batteries on the 787.

Quoting PassedV1 (Reply 35):
I know WHY these batteries were chosen, but it is the WRONG reason, and if the players involved were part of the right culture, it would NOT have happened.

They absolutely were chosen for all the right reasons. They will get to the bottom of this and come up with a good fix. The players are of the right culture, what are you suggesting ? That is out of line and smearing the folks who developed this aircraft.

Quoting PassedV1 (Reply 35):
Don't get me wrong, I am not against new technology in airplanes. If Harrison Ford wants to use one on his G-V, knock yourself out. With airliners though, there is a different standard.

Which is in place. Believe it.

Quoting lightsaber (Reply 43):
On reason Lithium batteries were chosen is to make the weight penalty low enough while providing the needed number of APU starts for ETOPS 330 as well as any other loads that I am unaware of.

And on the 787, have enough battery left for braking.

Quoting bellancacf (Reply 49):
Was that case filled with fluid? If not, is that lump in the center the bundle of cells? And if you knew the thing was prone to thermal runaway, with all that space, why on earth wouldn't you have provided cooling? Now I'm well and truly puzzled by this whole affair.
Quoting Wisdom (Reply 54):
-The liquid solution is flammable. Flammable means that if lit on fire, it will burn. This is why one needs to be careful when transporting li-ion batteries on an aircraft. If a battery gets damaged and the liquid flows into an electrical assembly, it could be lit on fire.

No chance. The electrolyte in the 787 batteries is a paste. At high temperatures, it turns into a very gooey paste. It is not a liquid like in lead-acid batteries. Have heard it has cobalt in it.
You are here.
 
phxa340
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:29 pm

Quoting PHX787 (Reply 56):

You and your "contacts" .... I wish I had some.
 
RickNRoll
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:30 pm

Quoting CALTECH (Reply 57):
No chance. The electrolyte in the 787 batteries is a paste. At high temperatures, it turns into a very gooey paste. It is not a liquid like in lead-acid batteries. Have heard it has cobalt in it.

From the FAA press release

The battery failures resulted in release of flammable electrolytes, heat damage, and smoke on two Model 787 airplanes. The root cause of these failures is currently under investigation. These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment.

So they are saying that at issue is the release of flammable electrolytes.
 
SonomaFlyer
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:32 pm

Thanks for the info Wisdom.

Quoting RickNRoll (Reply 59):
So they are saying that at issue is the release of flammable electrolytes.

The heated gooey paste mentioned by CALTECH is presumably the electrolytes mentioned in the FAA order. While flammable, it requires an ignition source to burn.
 
PHX787
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:36 pm

Quoting phxa340 (Reply 58):

Quoting PHX787 (Reply 56):

You and your "contacts" .... I wish I had some.


Go find some   I met all mine through being in japan for an extended period of time, being involved at ASU, and meeting friends of friends through Facebook and around japan/Arizona.

Seriously it's not that hard. This particular contact is a writer and journalist. His clearance doesn't allow him to contact companies as when journalism majors graduate they must first go into crime investigations.
Follow me on twitter: www.twitter.com/phx787
 
RickNRoll
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:38 pm

Quoting SonomaFlyer (Reply 60):
The heated gooey paste mentioned by CALTECH is presumably the electrolytes mentioned in the FAA order. While flammable, it requires an ignition source to burn.

That's not the point. The point is, the FAA doesn't want it there, at all. Even if the fault is traced to a bad batch of batteries, they are telling Boeing they don't want the potential for the internal electrolyte to escape to exist.
 
SonomaFlyer
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:42 pm

Quoting RickNRoll (Reply 62):
The point is, the FAA doesn't want it there, at all. Even if the fault is traced to a bad batch of batteries, they are telling Boeing they don't want the potential for the internal electrolyte to escape to exist.

I agree that's what the FAA wants. We'd have to see the special conditions on the certification of the electrical system to see what the containment unit was supposed to do other than protect the a/c in the event of a battery fire/"thermal event."
 
RickNRoll
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:47 pm

Quoting SonomaFlyer (Reply 63):
I agree that's what the FAA wants. We'd have to see the special conditions on the certification of the electrical system to see what the containment unit was supposed to do other than protect the a/c in the event of a battery fire/"thermal event."

At a guess, this was not covered adequately. Now that we have had the battery failures, the FAA is revising it's requirements.
 
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CALTECH
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:51 pm

Quoting RickNRoll (Reply 59):
From the FAA press release

The battery failures resulted in release of flammable electrolytes, heat damage, and smoke on two Model 787 airplanes. The root cause of these failures is currently under investigation. These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment.

So they are saying that at issue is the release of flammable electrolytes.
Quoting RickNRoll (Reply 59):
The heated gooey paste mentioned by CALTECH is presumably the electrolytes mentioned in the FAA order. While flammable, it requires an ignition source to burn.
Quoting RickNRoll (Reply 62):
That's not the point. The point is, the FAA doesn't want it there, at all. Even if the fault is traced to a bad batch of batteries, they are telling Boeing they don't want the potential for the internal electrolyte to escape to exist.
Quoting SonomaFlyer (Reply 63):
I agree that's what the FAA wants. We'd have to see the special conditions on the certification of the electrical system to see what the containment unit was supposed to do other than protect the a/c in the event of a battery fire/"thermal event."

Meant 'no chance' because it is not a liquid. If it is thought that I do not know that the battery and it's electrolyte paste spewed over the compartment, and was heated to a much higher temp than when it turns into a gooey paste, well, I am sorry my post was misinterpeted or misread.That's the point I was referring to, the electrolyte is not a liquid.

These batteries do not like heat, and they generate a lot of heat when cycling, like in APU starts.

[Edited 2013-01-17 14:53:56]
You are here.
 
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Aesma
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 10:58 pm

Quoting CALTECH (Reply 65):
Meant 'no chance' because it is not a liquid.

Something that can flow is a liquid. Even glass is a liquid if you wait long enough, since it will flow.
New Technology is the name we give to stuff that doesn't work yet. Douglas Adams
 
Shenzhen
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:09 pm

Quoting RickNRoll (Reply 62):
Quoting SonomaFlyer (Reply 60):
The heated gooey paste mentioned by CALTECH is presumably the electrolytes mentioned in the FAA order. While flammable, it requires an ignition source to burn.

That's not the point. The point is, the FAA doesn't want it there, at all. Even if the fault is traced to a bad batch of batteries, they are telling Boeing they don't want the potential for the internal electrolyte to escape to exist.

Here is the actual text from the AD.....

AD Requirements
This AD requires modification of the battery system, or other actions, in accordance with a
method approved by the Manager, Seattle Aircraft Certification Office (ACO), FAA.

Unsafe Condition
This AD was prompted by recent incidents involving lithium ion battery failures that resulted
in release of flammable electrolytes, heat damage, and smoke on two Model 787-8 airplanes. The
cause of these failures is currently under investigation. We are issuing this AD to prevent damage to critical systems and structures, and the potential for fire in the electrical compartment.
---------------------------------------------
The main issue is the battery failures.
 
RickNRoll
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:14 pm

Quoting Shenzhen (Reply 67):
This AD was prompted by recent incidents involving lithium ion battery failures that resulted
in release of flammable electrolytes, heat damage, and smoke on two Model 787-8 airplanes. The
cause of these failures is currently under investigation. We are issuing this AD to prevent damage to critical systems and structures, and the potential for fire in the electrical compartment.
---------------------------------------------
The main issue is the battery failures.

I suppose it is ambiguous, but to me they are concerned abou tht fact that a battery failure resulted in the release of electrolytes. Planes have all the redundant systems and ETOPS based on the knowledge that something will fail, not that they can prevent it from ever failing again. They certainly want the cause for the battery failures fixed, which could well be a bad batch of batteries. They also want the release of electrolytes prevented from happening again if a battery every fails again as well.
 
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DocLightning
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:23 pm

Quoting kanban (Reply 1):

posted this just before cut off
Yuasa makes these batteries for many land surface operations, trains, trucks, etc. and seem to have no problems. Possibly could the problem be related to the pressure differentials when flying... ie water boils at a lower temperature at elevation, so could the organic fluid in these batteries "boil" at altitude and leave the anodes/cathodes bare and in contact?

IIRC, the maximum cabin altitude aboard the 787 is something like 6,000 feet, right? Now, DEN is at 5,400 feet. So if Yuasa actually designed a battery that would "boil" while on the ground at DEN and lead to an event like this, then someone there is guilty of criminal negligence. This company has a lot of experience producing Li-ion batteries, so I think it's unlikely that they were that blatantly incompetent.

I'm no engineer, but I do make a living out of diagnosing problems. It strikes me that the issue is more likely to be in the interaction between the battery and the aircraft's electrical system.

Quoting IBOAviator (Reply 9):
I am going to get flamed for this but I am going to look at the FDA for just a minute. From the outside, a reasonably 'good' governing body but a closer look unfolds a ton of corruption.

Only if you read websites that peddle "organic" and "alternative" foods and medicines. The FDA has had its problems and corruption, but these issues have been the exception and not the norm. In fact, the FDA is so strict that if aspirin were to go up for FDA review today, it would never pass.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
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Stitch
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:39 pm

Quoting DocLightning (Reply 69):
It strikes me that the issue is more likely to be in the interaction between the battery and the aircraft's electrical system.

It strikes me that this would be one of the more unlikely causes, for otherwise I would expect we would have seen it happen much more frequently considering the amount of hours the battery and the aircraft's electrical system have been interacting across testing, certification and revenue service. Plus the lab and bench testing prior to first flight.

If this interaction can cause two events in less than two weeks, considering the 787 has been flying daily in revenue service for a year prior, I would think statistically we should have seen many more of these events with NH and JL birds, at least.

That being said, even if the investigation does show that the batteries themselves were the root cause, Boeing will still need to address the fact that bad batteries can fail in a way that appears to contravene one or more of the special conditions that allowed their use.

[Edited 2013-01-17 15:45:08]
 
PHX787
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:44 pm

Quoting DocLightning (Reply 69):
IIRC, the maximum cabin altitude aboard the 787 is something like 6,000 feet, right? Now, DEN is at 5,400 feet. So if Yuasa actually designed a battery that would "boil" while on the ground at DEN and lead to an event like this, then someone there is guilty of criminal negligence. This company has a lot of experience producing Li-ion batteries, so I think it's unlikely that they were that blatantly incompetent.

This.

Yuasa needs to provide proof that there is no negligence or other issues which I personally believe they can do. However, this probe is going to most likely come up with things such as 1) why didn't Yuasa take into account factors such as overcharge, containment, and overheat, 2) why Yuasa-made batteries are just now failing a year and some change into service (even with the supposed battery replacement in 804) and both Yuasa and Boeing need to go back to their testing logs to see at which points anomalies like this would have happened.

  

On other terms seems like this is developing into a scandal in japan, but just like us, people don't quite know who is blaming who here.
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Shenzhen
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:52 pm

Quoting PHX787 (Reply 71):
This.

Yuasa needs to provide proof that there is no negligence or other issues which I personally believe they can do. However, this probe is going to most likely come up with things such as 1) why didn't Yuasa take into account factors such as overcharge, containment, and overheat, 2) why Yuasa-made batteries are just now failing a year and some change into service (even with the supposed battery replacement in 804) and both Yuasa and Boeing need to go back to their testing logs to see at which points anomalies like this would have happened.

The batteries would have been tested to meet both certification and Boeing requirements. For the FAA requirements, one of their representatives would have been there to ensure the batteries met drawing/specification requirements during test, then signed on the dotted line, otherwise it wouldn't be on the airplane.

There is a reason why everything to do with airplanes is expensive, and most of it has to do with the upfront costs, including the testing required for certification.

Cheers
 
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DocLightning
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:54 pm

Quoting Stitch (Reply 70):
It strikes me that this would be one of the more unlikely causes, for otherwise I would expect we would have seen it happen much more frequently considering the amount of hours the battery and the aircraft's electrical system have been interacting across testing, certification and revenue service. Plus the lab and bench testing prior to first flight.

You could say that of any potential cause, I suppose. Why did this not happen until five days ago...and then twice in three days? The aircraft were delivered a year apart and even if the batteries were from the same batch (or however they make it), they've seen different use, so why did they both fail at the same time?

Obviously, the problem is somewhere. Assuming that the same thing occurred on both airframes (and I'd consider it far more ominous if the failures were unrelated), where do you suppose the problem is most likely to be?
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
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bellancacf
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FAA Grounds 787 Part 2

Thu Jan 17, 2013 11:55 pm

Anybody need a funny coincidence? Some years ago I sat near a bunch of Boeing reps on a flight and talked with one of them about their new plane. They'd come from a conference with the Japanese, and out of a list of possible names for the plane, the Japanese had picked "787", this fellow said. He said that they, the reps, understood that to the Japanese, "7-8-7" was particularly lucky and propitious, so, why not, Boeing was going to go along with the choice. I remarked that "7-8-7" was the "young bright/young dark/young bright" trigram in the I Ching whose name was "Li" and which symbolized "fire"; was that what the Japanese liked about it, the relationship between fire and a jet engine? No idea, said the rep, but that's what they want.

So now, we have the "787" with "Li" batteries which are causing if not the "f"-word, then considerable heat and fury.

Hopefully that was good for a chuckle.

Can anybody tell me whether the temp of the battery is monitored and whether there's a cooling system? I still haven't figured that out from the information here.

Thanks.
 
CM
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:11 am

Bellancacf,

All of the questions you continue to ask were answered in post #22.

Quoting bellancacf (Reply 76):
Can anybody tell me whether the temp of the battery is monitored and whether there's a cooling system? I still haven't figured that out from the information here.
Quoting CM (Reply 22):
Yes, the Main and APU batteries both have active temperature monitoring.



Quoting bellancacf (Reply 49):
Was that case filled with fluid?
Quoting CM (Reply 22):
There is no cooling provision in the 787 battery architecture.



Quoting bellancacf (Reply 49):
And if you knew the thing was prone to thermal runaway, with all that space, why on earth wouldn't you have provided cooling?
Quoting CM (Reply 22):
Actively cooling the batteries would certainly be possible and active air-cooling is common in Ni-Cd batteries on some other aircraft (777 batteries have an integral fan), but this would not have helped in the case of the two battery incidents on the 787. Thermal runaway in a Li-ion battery is not typically brought on by high operating temperatures (although it could be). There are much more common causes of thermal runaway such as internal defects and problems with managing the state of charge. Once the battery begins a thermal runaway, no amount of cooling will help; the process is exothermic and is self sustained until the energy source (lithium) is depleted.


[Edited 2013-01-17 16:12:55]
 
RickNRoll
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:14 am

Hi CM.

Apart from working out why the batteries failed, which could well be a bad batch, does the FAA require a change in the containment/venting/release of electrolyte management?
 
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Stitch
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:17 am

Quoting DocLightning (Reply 75):
Assuming that the same thing occurred on both airframes (and I'd consider it far more ominous if the failures were unrelated), where do you suppose the problem is most likely to be?

Assuming the same issue occurred on both airframes, I would look to the batteries themselves. We can assume the JL bird had a recent battery since it was the most recently-completed line number to be delivered. And there have been reports that NH replaced the battery on their bird, so if true, that would imply two "young" batteries. There have also been reports that both batteries came from the same production batch.

If bad batteries are the root cause, then yes, that would be due to the interaction between the (bad) battery and the aircraft's electrical system. But the interaction between a good battery and the aircraft's electrical system may cause no issues.



Quoting bellancacf (Reply 76):
Can anybody tell me whether the temp of the battery is monitored and whether there's a cooling system? I still haven't figured that out from the information here.

Yes, battery temperature is monitored. The NH flight crew I believe were receiving notifications that the battery temperature was rising.

There is no active cooling of the battery beyond the air flow in the EE bay. That being said, once a cell in a Li-Ion battery enters thermal runaway, the reaction is exothermic and therefore even an active cooling system would not be effective in preventing the battery temperature from increasing after that reaction begins.

[Edited 2013-01-17 16:47:35]
 
bellancacf
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:28 am

to CM @ 77 and 22 -- Ack! Sorry! Went out on an errand and whizzed right by that when I came back. So the Li goes exothermic and you can't stop it from doing it or stop it once started. Great. My belated thanks for your reply!
 
iahmark
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:29 am

Well, here’s an idea…. maybe the batteries are underrated for the current drain/usage/needs of the plane; in other words we know Li ion produces good energy for their size but reading all that has been said it looks like this plane uses/drains massive amounts of energy from its batteries causing to them to generate a lot heat, much more so than they were designed /rated for; all these charge/ discharge cycles would take a toll on the longevity of the battery.

This this analogous to the alternator/battery combo on a lot cars, a lot of them that get used/sold in colder weather regions get an option of a heavy duty alternator/battery for the same reason.

I believe Boeing may have underestimated the electrical needs of this plane, the fault may not be the battery itself but the interaction between the battery and the electrical needs of the plane, maybe it needs bigger or higher rated battery;
a higher rated battery may weight more but it could power all these ancillary systems without deep discharges/drains.
 
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Stitch
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:41 am

Quoting iahmark (Reply 81):
I believe Boeing may have underestimated the electrical needs of this plane...

I would hope Boeing knows the draw the electrical system on the 787 requires and scaled battery capacity as necessary.

In fact, I would think they would be required to exactly know how much the system requires since the battery would need to be able to provide sufficient power in the event both engines failed, taking their respective four generators with them, and the APU failed to engage.
 
SonomaFlyer
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:47 am

Quoting Stitch (Reply 82):
Quoting iahmark (Reply 81):
I believe Boeing may have underestimated the electrical needs of this plane...

I would hope Boeing knows the draw the electrical system on the 787 requires and scaled battery capacity as necessary.

In fact, I would think they would be required to exactly know how much the system requires since the battery would need to be able to provide sufficient power in the event both engines failed, taking their respective four generators with them, and the APU failed to engage.

Electrical load requirements are part of the design and certification process; Boeing knows exactly how much electricity is required to run the systems in normal and emergency situations. All of that information is part of the package which was signed off by the FAA following testing. I cannot imagine this will come down to an "undersized" battery.

I think its better to focus on the battery itself and the charging system given the symptoms which were made public. Heavy draws etc causing issues with the battery would be addressed as part of the battery analysis I believe given the loads were a known quantity to all stake holders.
 
prebennorholm
Posts: 7098
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 12:50 am

Quoting DocLightning (Reply 69):
IIRC, the maximum cabin altitude aboard the 787 is something like 6,000 feet, right? Now, DEN is at 5,400 feet. So if Yuasa actually designed a battery that would "boil" while on the ground at DEN and lead to an event like this, then someone there is guilty of criminal negligence.

These batteries are sure made to tolerate a cabin decompression at FL450. We can just forget about any altitude related thing having caused this mess.
Always keep your number of landings equal to your number of take-offs
 
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DocLightning
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:03 am

Quoting Stitch (Reply 79):
And there have been reports that NH replaced the battery on their bird, so if true, that would imply two "young" batteries. There have also been reports that both batteries came from the same production batch.

I very much hope that is the issue. If it's down to a defective batch of batteries, that will be very easy to fix and the aircraft might be in the air again within days. If the issue is in the electrical system, then it could be months.
-Doc Lightning-

"The sky calls to us. If we do not destroy ourselves, we will one day venture to the stars."
-Carl Sagan
 
CM
Posts: 623
Joined: Wed Feb 08, 2012 4:17 am

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:05 am

Quoting bellancacf (Reply 80):
to CM @ 77 and 22 -- Ack! Sorry! Went out on an errand and whizzed right by that when I came back. So the Li goes exothermic and you can't stop it from doing it or stop it once started. Great. My belated thanks for your reply!

No worries, when a thread moves this fast, it gets impossible to keep up with it.



Quoting RickNRoll (Reply 78):
Hi CM.

Apart from working out why the batteries failed, which could well be a bad batch, does the FAA require a change in the containment/venting/release of electrolyte management?

The active NTSB investigation and FAA inquiry really limit what I can say about this. However, the text of the FAA AD is informative about what aspects of a battery failure they are concerned about and will be taking a closer look at in determining whether a design change is needed:

"This AD was prompted by recent incidents involving lithium ion battery failures that resulted in release of flammable electrolytes, heat damage, and smoke on two Model 787-8 airplanes. The cause of these failures is currently under investigation. We are issuing this AD to prevent damage to critical systems and structures, and the potential for fire in the electrical compartment."



Quoting iahmark (Reply 81):
I believe Boeing may have underestimated the electrical needs of this plane

This particular battery was chosen (in part) based on the electrical needs of the airplane. The 787 battery does everything it is supposed to do in terms of electrical power. Understanding if the battery is maintaining an acceptable state of charge during normal, operations is fundamental to the qualification of the battery. Beyond that, abuse and endurance testing has looked at how the battery behaves when used considerably outside of what would be considered "normal operations" - it must remain within a safe state of charge during these types of operation as well. The battery being undersized for its role is a very low probability place to find the root cause of the battery failures.

Quoting SonomaFlyer (Reply 83):
Electrical load requirements are part of the design and certification process; Boeing knows exactly how much electricity is required to run the systems in normal and emergency situations. All of that information is part of the package which was signed off by the FAA following testing. I cannot imagine this will come down to an "undersized" battery.

        



Quoting prebennorholm (Reply 84):
These batteries are sure made to tolerate a cabin decompression at FL450. We can just forget about any altitude related thing having caused this mess.

        
 
Shenzhen
Posts: 1666
Joined: Wed Jun 25, 2003 12:11 pm

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:05 am

Quoting Stitch (Reply 82):
I would hope Boeing knows the draw the electrical system on the 787 requires and scaled battery capacity as necessary.

In fact, I would think they would be required to exactly know how much the system requires since the battery would need to be able to provide sufficient power in the event both engines failed, taking their respective four generators with them, and the APU failed to engage.

Every airplane delivered comes with an electrical load analysis, witch provides the loads on each and every buss. Airlines need this information, as they like to add to the loads, like inflight entertainment, new seats/classes, wifi, gallies, and such.

In addition, different airplane configurations (customers) have different loads (probably not on the battery busses).

Cheers
 
rcair1
Posts: 1147
Joined: Wed Oct 28, 2009 8:39 pm

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:24 am

Quoting airmagnac (Reply 7):
And I welcome his enlightening insights in this otherwise sad mess. So thanks man ! from an Airbus system engineer.

Well said.

Quoting SonomaFlyer (Reply 19):
A simple heightened inspection program won't cut it in this case.

It may very well "cut it" if the problem is determined to be related to something that can be inspected. However, I would expect that it would more likely be a short term inspection program while a longer term fix was developed.

Quoting ZB052 (Reply 27):
Oh, and *FIRST POST* (Have lurked here for close to a decade - finally decided to register!)

Yay!

Yay! Welcome. And since you have been lurking - you probably already have the thick skin required.

Quoting RickNRoll (Reply 46):
the FAA says the current venting system has to be redone.

The FAA has said nothing of the sort. They have said they are investigating.

Quoting PHX787 (Reply 71):
Yuasa needs to provide proof that there is no negligence or other issues which I personally believe they can do. However, this probe is going to most likely come up with things such as 1) why didn't Yuasa take into account factors such as overcharge, containment, and overheat, 2) why Yuasa-made batteries are just now failing a year and some change into service (even with the supposed battery replacement in 804) and both Yuasa and Boeing need to go back to their testing logs to see at which points anomalies like this would have happened.

I haven's seen a cart that far ahead of a horse in a long time.
rcair1
 
Shenzhen
Posts: 1666
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:33 am

NTSB Investigation UPDates - Quantity - 2

NTSB provides investigative update on Boeing 787 fire incident in Boston
January 08

WASHINGTON - The National Transportation Safety Board today released an update on its formal investigation of Monday's fire aboard a Japan Airlines Boeing 787 at Logan International Airport in Boston. There were no passengers or crew on board at the time. One firefighter received minor injuries.

In addition to an investigator already on scene who visually inspected the airplane last night, the NTSB has sent two additional investigators to Boston and formed investigative groups to look at airworthiness and fire and airport emergency response. Senior Air Safety Investigator David Helson has been designated as the investigator-in-charge.

Parties to the investigation are the Federal Aviation Administration and The Boeing Company. In addition, the Japan Transport Safety Board has appointed an accredited representative and Japan Airlines will assist the JTSB as technical advisors.

Initial investigative findings include:

The NTSB investigator on scene found that the auxiliary power unit battery had severe fire damage. Thermal damage to the surrounding structure and components is confined to the area immediately near the APU battery rack (within about 20 inches) in the aft electronics bay.
Preliminary reports from Japan Airlines representatives indicate that airplane maintenance and cleaning personnel were on the airplane with the APU in operation just prior to the detection of smoke in the cabin and that Boston Logan Airport Rescue and Fire Fighting were contacted.
Rescue and fire personnel and equipment responded to the airplane and detected a fire in the electronics and equipment bay near the APU battery box. Initial reports indicate that the fire was extinguished about 40 minutes after arrival of the first rescue and fire personnel. One firefighter received minor injuries.
--------------------------------------

NTSB Provides Second Investigative Update on Boeing 787 Battery Fire in Boston

WASHINGTON - The National Transportation Safety Board today released a second update on its investigation into the Jan. 7 fire aboard a Japan Airlines Boeing 787 at Logan International Airport in Boston.

The lithium-ion battery that powered the auxiliary power unit on the airplane was removed and transported back to the NTSB Materials Laboratory in Washington on Jan. 10. The battery is currently being examined by NTSB investigators, who plan to disassemble it this week.

In advance of that work, under the direction of the NTSB, radiographic examinations of the incident battery and an exemplar battery were conducted this past weekend at an independent test facility. The digital radiographs and computed tomography scans generated from this examination allowed the team to document the internal condition of the battery prior to disassembling it.

In addition, investigators took possession of burned wire bundles, the APU battery charger, and several memory modules. The maintenance and APU controller memory modules will be downloaded to obtain any available data. Investigators also documented the entire aft electronics bay including the APU battery and the nearby affected structure where components and wire bundles were located. The airplane was released back to Japan Airlines on Jan. 10.

The airplane's two combined flight data recorder and cockpit voice recorder units were transported to NTSB headquarters and have been successfully downloaded. The information is currently being analyzed by the investigative team.

The airport emergency response group documented the airport rescue and firefighting efforts to extinguish the fire, which included interviews with first responders. Fire and rescue personnel were able to contain the fire using a clean agent (Halotron), however, they reported experiencing difficulty accessing the battery for removal during extinguishing efforts. All fire and rescue personnel responding to the incident had previously received aircraft familiarization training on the Boeing 787. In accordance with international investigative treaties, the Japan Transport Safety Board and French Bureau d'Enquêtes et d'Analyses pour la sécurité de l'aviation civile have appointed accredited representatives to the investigation. The NTSB-led investigative team is comprised of subject matter groups in the areas of airplane systems, fire, airport emergency response, and data recorders and includes experts from the Federal Aviation Administration, The Boeing Company, US Naval Surface Warfare Center's Carderock Division, Japan Airlines (aircraft operator), GS Yuasa (battery manufacturer), and Thales Avionics Electrical Systems (APU battery/charger system).

Sorry if this was already posted....
 
USAirALB
Posts: 2342
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:36 am

Unfortunately I have little knowledge when it comes to the "TechOps" sector of flying, so please excuse me if this has been discussed before, or if it is a stupid question, but why are these problems all coming out now? ANA has been flying the plane for over a year, and I don't remember problems like this when they first starting flying.

As many has said before, I feel deeply sorry for the events that have happened, and I feel almost embarrassed(?) as an American that Boeing, the last great American aircraft manufacturer is having these issues. I worry that people, airlines, and other countries will lose faith in the 787, and possibly Boeing.

I saw these two ad's on youtube a couple of days ago, and I thought I would share them. From the time these commercials were shot (2005?) we had great hopes for the 787, and I know the hopes will come true.

http://www.youtube.com/watch?v=EqrBOBM-AXA

http://www.youtube.com/watch?v=jXx4CGNAFQ4
RJ85, F70, E135, E140, E145, E70, E75, E90, CR2, CR7, CR9, 717, 732, 733, 734, 735, 73G, 738, 739, 744ER, 752, 753, 762, 772, 77E, 77W, 789, 319, 320, 321, 332, 333, 343, 359, 388
 
rcair1
Posts: 1147
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:40 am

Quoting USAirALB (Reply 90):
but why are these problems all coming out now? ANA has been flying the plane for over a year, and I don't remember problems like this when they first starting flying.

That is not a stupid question - it is one of the key questions. You may not have seen it, but the 2 a/c are of significantly different ages - the ANA 787 has been in service ~ a year, the JAL one just entered service. However there are UNCONFIRMED reports that the battery in the ANA a/c was recently replaced, so the batteries MAY be of similar vintage.
rcair1
 
aerodog
Posts: 114
Joined: Tue Jun 13, 2006 10:48 am

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:44 am

Quoting dfambro (Reply 25):


Things can go wrong, in aviation and in pharma, but that doesn't mean there is a conspiracy to subvert proper regulation.

In terms of the FAA, I used to believe that...not anymore. A pip-squeak CEO from Albuquerque, Vern Raburn convinced the FAA brass in Washington that the local MIDO inspectors were impeding certification of his Eclipse Very Light Jet. The orders came down and the inspectors were not allowed to inspect below the floor panels. John Hickey had his finger prints all over that episode. Hickey is now deeply involved in the 787 certification program.

There is plenty of information regarding this online including YouTube video of a Congressional Hearing headed by Rep. James Oberstar:

http://www.youtube.com/user/PASSMIDO

The two FAA members appearing at the hearing were Hickey and Nick Sabatini. Sabatini retired shortly after the hearing.

There was a grievance filed as well:

http://www.avweb.com/newspics/grievance-EclipseTC-AIR402.pdf

And other media reports:

http://www.aero-news.net/index.cfm?d...0f5cb3-46c1-41eb-9a84-3c469b2247d9

http://www.redorbit.com/news/busines...roval_of_jet_design_officials_say/

So if Raburn had that much sway over the FAA, I can only imagine the influence Boeing might have.
 
RickNRoll
Posts: 1869
Joined: Fri Jan 06, 2012 9:30 am

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:48 am

Quoting rcair1 (Reply 88):
Quoting RickNRoll (Reply 46):the FAA says the current venting system has to be redone.The FAA has said nothing of the sort. They have said they are investigating.

I don't know of any other way of preventing the electrolyte escaping form a failing battery than doing something about the containment system, which didn't work.
 
sphealey
Posts: 322
Joined: Tue May 31, 2005 12:39 am

FAA Grounds 787 Part 2

Fri Jan 18, 2013 1:50 am

Quoting rcair1 (Reply 91):

Quoting USAirALB (Reply 90):
but why are these problems all coming out now? ANA has been flying the plane for over a year, and I don't remember problems like this when they first starting flying.


That is not a stupid question - it is one of the key questions. You may not have seen it, but the 2 a/c are of significantly different ages - the ANA 787 has been in service ~ a year, the JAL one just entered service. However there are UNCONFIRMED reports that the battery in the ANA a/c was recently replaced, so the batteries MAY be of similar vintage.

What would the lay-up procedure have been for the initial test units (ZA001, ZA002, etc)? Would the batteries have been removed before the planes went into storage? If so, where would they have gone? Seems that those might be useful sources of information about degradation due to clock time and/or operations.

sPh
 
PHX787
Posts: 7892
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FAA Grounds 787 Part 2

Fri Jan 18, 2013 2:03 am

Quoting Shenzhen (Reply 72):
There is a reason why everything to do with airplanes is expensive, and most of it has to do with the upfront costs, including the testing required for certification.

Just a heads up you posted this 3 times  

Either way, that is a good and valid point....but The one point I wanna make is why weren't these seen previously during testing? is it impossible to predict stuff like this during initial testing?

Quoting rcair1 (Reply 88):
I haven's seen a cart that far ahead of a horse in a long time.

It's just an assumption based off what I read. Just some re-hashing and some thinking.

Quoting Shenzhen (Reply 89):
The NTSB investigator on scene found that the auxiliary power unit battery had severe fire damage. Thermal damage to the surrounding structure and components is confined to the area immediately near the APU battery rack (within about 20 inches) in the aft electronics bay.

So hm..... even if the battery was replaced, could the aircraft be safe enough to ferry back to Japan or is it not safe enough?
Follow me on twitter: www.twitter.com/phx787
 
Shenzhen
Posts: 1666
Joined: Wed Jun 25, 2003 12:11 pm

FAA Grounds 787 Part 2

Fri Jan 18, 2013 2:09 am

Quoting RickNRoll (Reply 93):
I don't know of any other way of preventing the electrolyte escaping form a failing battery than doing something about the containment system, which didn't work.

Requiring some type of shield wouldn't be unheard of. A United 777 caught fire in load center/panel and the damage was considerable. The FAA released an AD to add extra containment to catch the dripping material that caused the fire to be much worse.

Here is a link...

http://www.thetechherald.com/article...777-escapes-Heathrow-fire-disaster
 
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CALTECH
Posts: 3428
Joined: Thu May 17, 2007 4:21 am

FAA Grounds 787 Part 2

Fri Jan 18, 2013 2:27 am

Quoting Aesma (Reply 66):
Something that can flow is a liquid. Even glass is a liquid if you wait long enough, since it will flow.

Again, the electrolyte is not a liquid. If it was heated enough, it might become a liquid, but we are told it is a paste. Closely guarded paste. And in these incidents, the heat and thermal runaway would look like a arc welder. I do not know if the paste stays as a paste or turns into a liquid. Certainly a paste could spew from a containment vessel if the heat and pressure rose high enough.

According to the statement in post #66, so aluminum and steel, among other substances, must be liquids because they will 'flow' if you heat them up enough too.

Glass is unique, it seems to be a solid but still flows. In old churches it is known that the stained glass becomes very thin at the top of a pane and thicker near the bottom as the glass flows down over the centuries.

These batteries get very hot, even under normal cycling.
You are here.
 
Wisdom
Posts: 179
Joined: Thu Apr 28, 2011 5:43 pm

FAA Grounds 787 Part 2

Fri Jan 18, 2013 2:29 am

Quoting CALTECH (Reply 57):

No chance. The electrolyte in the 787 batteries is a paste. At high temperatures, it turns into a very gooey paste. It is not a liquid like in lead-acid batteries. Have heard it has cobalt in it.

Are you sure? Most li-ion batteries have liquid electrolytes.

If true, that's new information for me. What kind of paste is it?
Most li-ion batteries have liquid electrolytes for the obvious reasons of facilitating transfer of ions.

I don't see any merits of using a solid electrolyte for li-ion applications, although I have heard that some experimenting is going on.
 
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CALTECH
Posts: 3428
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RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 3:06 am

Quoting Wisdom (Reply 92):
Are you sure? Most li-ion batteries have liquid electrolytes.

As sure as I haven't looked inside one yet, but that is what is being said. It is a paste. The electrolyte is a non-aqueous electrolyte paste composed mainly of Li-Ion solution, cobalt, and a proprietary powder. No sources, sorry.
You are here.
 
RickNRoll
Posts: 1869
Joined: Fri Jan 06, 2012 9:30 am

RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 3:25 am

Quoting Shenzhen (Reply 90):
Requiring some type of shield wouldn't be unheard of. A United 777 caught fire in load center/panel and the damage was considerable. The FAA released an AD to add extra containment to catch the dripping material that caused the fire to be much worse.

It already has a container, which seemed to stop the fire spreading in the original incident. In the second incident, it didn't stop the electrolyte from splashing around the electronics bay. We don't know yet if it contained the flames completely, since the fire service removed it, possibly interfering with the container.
 
nm2582
Posts: 177
Joined: Tue Jun 26, 2007 2:15 pm

RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 4:49 am

I think that a lot of the questioning of the 787's overall electrical systems and design is misguided. It seems highly unlikely that the whole thing would just be trash. In fact, all airborne electrical issues thus far, the system has tolerated the issue and continued to provide power to the aircraft so that a safe landing was possible, and reportedly (ZA002) even recovered systems after the failure as the system reconfigured. If anything, that should tell us that the aircraft is actually pretty fault tolerant; there just needs to be less faults!

With specific regards to the batteries - it's clear they have an issue to solve, but an issue with battery management (whether it be charging, discharging, wiring, whatever) does not implicate the whole electrical system.

Lithium cells don't just spontaneously go into thermal runaway or vent for no good reason, it's a chain of events that can be triggered in many ways - over-charge, over-discharge, manufacturing defect, physical damage to the cell, etc.; or anything which causes these to occur.

I believe that a relatively straightforward problem (cell defect, software defect, wiring defect) will be discovered (even if it is challenging at first to discover), and when discovered, it will be resolved and this will be the end of the issue.

The A380 has already proven that lithium cells can fly safely.
 
RickNRoll
Posts: 1869
Joined: Fri Jan 06, 2012 9:30 am

RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 4:58 am

Quoting nm2582 (Reply 95):
I believe that a relatively straightforward problem (cell defect, software defect, wiring defect) will be discovered (even if it is challenging at first to discover), and when discovered, it will be resolved and this will be the end of the issue.

Except that the current containment of any failure has not worked to the satisfaction of the FAA. That is, even if they remedy the root cause of the failure, they still have to come up with a resolution to the problem of not coping adequately with the failure.
 
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lightsaber
Moderator
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RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 4:58 am

Quoting Shenzhen (Reply 41):
You can bet the numbers are being crunched and risk assesments are being put together for multiple "possible" solutions to the batteries overheating.

Agreed. But I'm certain dozens of engineers are working quite a bit of overtime to figure out the details.

Quoting RickNRoll (Reply 42):
Even if the batteries are fixed and there is no battery event again, the FAA says the current venting system has to be redone. The liquid that was sprayed around the inside of the forward bay had the potential to disrupt other systems in the plane.

Interesting. Do you have a link?

Quoting CALTECH (Reply 53):
And on the 787, have enough battery left for braking.

Tschhh... That's obviously optional. As long as the engines work, everyone love the plane.  
Quoting nm2582 (Reply 95):
I believe that a relatively straightforward problem (cell defect, software defect, wiring defect) will be discovered (even if it is challenging at first to discover), and when discovered, it will be resolved and this will be the end of the issue.

I hope it is the case. One that can be proven in the lab and proven to be corrected within the required safety margins.

Lightsaber
Winter is coming.
 
bonusonus
Posts: 229
Joined: Thu Nov 05, 2009 3:49 pm

RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 5:15 am

Quoting nm2582 (Reply 95):
The A380 has already proven that lithium cells can fly safely.

The A380 uses Li-ion batteries for its emergency lighting system. That seems like orders of magnitude less power than the 787 system which starts the APU and supplies main aircraft power...
 
RickNRoll
Posts: 1869
Joined: Fri Jan 06, 2012 9:30 am

RE: FAA Grounds 787 Part 2

Fri Jan 18, 2013 5:33 am

Quoting lightsaber (Reply 97):
Interesting. Do you have a link?

I have provided a few already. Here is one.

http://seattletimes.com/html/busines...ogy/2020148677_787groundedxml.html

Boeing Senior Vice President Mike Sinnett, who is responsible for the plane’s electrical systems, said in an interview last week after the Logan fire that those controls — two inside the battery and two external — would prevent any serious battery incident.

He added that Boeing tests showed that any smoke from less serious battery overheating caused by some internal flaw would exit through the outflow valves overboard, ensuring none entered the passenger cabin or the cockpit in flight.

But the FAA, announcing its decision Wednesday to ground the 787 fleet, indicated that it was not satisfied these systems worked as designed.

“These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment,” the FAA said.

Both battery incidents resulted in the “release of flammable electrolytes, heat damage, and smoke,” it said.


Boeing were of the opinion that the process of removing any smoke through outflow valves was adequate. The FAA disagrees, as there were also flammable electrolytes released, and smoke. They want this dealt with as well.

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