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Topic: FAA Grounds 787 Part 3
Username: NZ1
Posted 2013-01-19 02:14:57 and read 31990 times.

Please carry on discussion here. Previous thread was FAA Grounds 787 Part 2 (by iowaman Jan 17 2013 in Civil Aviation)

NZ1
Forum Moderator

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-19 02:26:49 and read 31980 times.

[Reposted from the other thread, as my post came right after the previous thread was closed]

Quoting spacecadet (Reply 196):
Quoting rcair1 (Reply 169):
The FAA believe it MAY BE a safety of flight issue.

Read what they wrote again, carefully:

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

I think you and some others are parsing out the word "could" to mean "well, it hasn't happened yet, so it's not yet a safety of flight issue, and may never be." But that's not what that means.

Again, we're in the middle of an interpretation problem, due to the subtlety of english vocabulary (differences between "is", "may be", "could", "is not")

Also, you seem to be thinking along the lines of "either it is safe, or it is not". This binary representation is only valid if you have a complete knowledge of the entire situation. Or more precisely, complete knowledge of every single chain of events that could be triggered by a battery issue, and of the consequences of these chains on the rest of the aircraft, so that you can actually assess the safety of the design.

But neither the FAA nor Boeing are omniscient, and probably do not have all this knowledge.
They know the batteries have a problem, they know smoke and electrolyte is projected outside of the containement box.
But this probably invalidates several of the hypotheses used for design and certification of the battery system. So they probably do not know precisely what could happen beyond the projection of smoke and electrolyte.
And they probably have come up with several potential scenarii in which catastrophic failures are a result.

Until these potential scenarii can be confirmed as impossible or sufficently highly unlikely, then these scenarii will have to be considered as a risk, and the appropriate safety measures will have to be taken.
But as the causes of the issue also seem unknown, we can't take any preventive measures directly on the batteries, such as checks and/or replacement. The batteries (at least the MAIN) cannot be removed for flight. So that leaves only one option, to ground the fleet

So to summarize, the situation here is not "the plane is unsafe". But rather "the 787 may very well be sufficiently safe, but it may also not be. We just don't know. And until we do know, then it will remain grounded"

Information is always the key...
And I do not have much more of it than anyone else here about the actual 787 events, which is why I added "probably" or "it seems", and will qualify this entire post as "my opinion".

Topic: RE: FAA Grounds 787 Part 3
Username: traindoc
Posted 2013-01-19 03:12:24 and read 31723 times.

Go to Bloomberg's website for an article on the LI ion batteries. The problem may be due to a bad batch of these batteries from a Japanese manufacturer. Certainly possible, in that the A/C involved are recent builds. The early build planes seem to not have this problem. At he Bloomberg website they have a picture of the remains of the battery from the JAL plane in Boston. Almost nothing left but the battery box, which survived the fire intact.

Reference here:

.http://www.businessweek.com/articles/2013-01-18/why-the-batteries-in-boeings-787-are-burning

Topic: RE: FAA Grounds 787 Part 3
Username: BLRAviation
Posted 2013-01-19 03:18:24 and read 31683 times.

@HAWK - I agree on the positioning flight. I specifically asked the AI PR department about VT-ANJ and whether AI would move the aircraft to BOM which is their main engineering base (you are the more knowledgeable person on that. They told me that they would fly engineers for the service to respective cities.

We too have the FAA EAD on our site. However, it is not clear.

Also my response was referring to the statement on the previous thread about test flights of the new 787s which are being produced. If empty flights are allowed like in the case of AI, then by the same logic, test flights should also be allowed.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-19 04:36:41 and read 31340 times.

Photo of the damaged NH battery alongside an undamaged battery. The cover has been removed in both.

Topic: RE: FAA Grounds 787 Part 3
Username: JerseyFlyer
Posted 2013-01-19 05:31:23 and read 31023 times.

This may have been posted in the locked Parts but Boeing has suspended 787 deliveries.

http://www.bbc.co.uk/news/business-21095056

They will need a large parking lot if the grounding is extended for weeks!

Topic: RE: FAA Grounds 787 Part 3
Username: Daysleeper
Posted 2013-01-19 05:48:27 and read 30893 times.

Quoting traindoc (Reply 2):
he problem may be due to a bad batch of these batteries from a Japanese manufacturer.

So this is a co-incidence? An aircraft with a history of electrical problems severe enough to cause arcing and fire just happens to have a bad batch of batteries installed causing yet more fires.

After reading though hundreds of posts on this subject I’m still none the wiser about this incident – The information just isn’t out there yet.

Topic: RE: FAA Grounds 787 Part 3
Username: art
Posted 2013-01-19 06:16:00 and read 30723 times.

Quoting JerseyFlyer (Reply 5):
This may have been posted in the locked Parts but Boeing has suspended 787 deliveries.

Why would any customer take delivery of an aircraft they could not use? A payment is made on delivery, too, IIRC.

Quoting Daysleeper (Reply 6):
After reading though hundreds of posts on this subject I’m still none the wiser about this incident – The information just isn’t out there yet.

Many interesting and informative posts from very knowlegeable a.netters, indeed. Could any of the cognoscenti hazard how long the grounding will be if it is determined that the problem is "simply" manufacturing defects in the batteries concerned? I ask because I imagine that if this were identified as the cause of the problem, it would be the simplest to resolve.

Topic: RE: FAA Grounds 787 Part 3
Username: petteri
Posted 2013-01-19 06:18:04 and read 30703 times.

I came across this interesting piece of news today. Of course this may be not at all related to the failures of the batteries that we've seen, as the complaints raised by this employee took place during the design phase of the batteries. The article talks about how this employee feels he was fired for pointing out flaws in the design of the battery.

http://www.dailykos.com/story/2013/0...ystem-fired-for-pointing-out-flaws

Of note it certainly appears that this employee had more going on in the work place than his complaint on the battery design and he did not gain Whistleblower protection from his dismissal from the company. The date on the letter from his lawyers is dated from 2011 so it does pre-date the current problems.

EDIT: This firm Securaplane is responsable for the charging unit of the battery.

[Edited 2013-01-19 06:21:49]

Topic: RE: FAA Grounds 787 Part 3
Username: aeroblogger
Posted 2013-01-19 06:21:06 and read 30681 times.

Quoting BLRAviation (Reply 3):
Also my response was referring to the statement on the previous thread about test flights of the new 787s which are being produced. If empty flights are allowed like in the case of AI, then by the same logic, test flights should also be allowed.

The ban of operations by the DGCA was a ban on revenue operations, not all operations.

The FAA may have different policies for US-flagged aircraft. Tests certainly can take place in India.

[Edited 2013-01-19 06:21:28]

Topic: RE: FAA Grounds 787 Part 3
Username: CXB77L
Posted 2013-01-19 07:03:50 and read 30378 times.

From Part 2:

Quoting spacecadet (Reply 196):
I think you and some others are parsing out the word "could" to mean "well, it hasn't happened yet, so it's not yet a safety of flight issue, and may never be." But that's not what that means. No design or construction flaw has ever caused an accident before it actually caused an accident; that doesn't mean the danger didn't exist before it did. It's like saying "my house doesn't need smoke detectors because it's never burned down before."

Obviously that's an extreme example - I am not saying were it not for this grounding, that there'd ever be a 787 crash due to a battery fire.

No, that's not what "could" means. It doesn't simply mean it won't happen because it hasn't happened yet, it means that it may or may not happen. That is not a certainty. The FAA are playing it safe, as it rightly should.

Quoting spacecadet (Reply 196):
But the word "could" there means the potential for damage to critical systems exists. When there is a condition that can lead to potential damage to critical systems, that is a safety of flight issue. And the plane wouldn't be grounded otherwise.

Replace the word "when" with "if" and that statement is more or less correct. To use "when" suggests that it will happen. That's not what the FAA are saying.

Quoting airmagnac (Reply 1):
Again, we're in the middle of an interpretation problem, due to the subtlety of english vocabulary (differences between "is", "may be", "could", "is not")

  

Topic: RE: FAA Grounds 787 Part 3
Username: boacvc10
Posted 2013-01-19 07:36:19 and read 30130 times.

Quoting petteri (Reply 8):
I came across this interesting piece of news today. Of course this may be not at all related to the failures of the batteries that we've seen, as the complaints raised by this employee took place during the design phase of the batteries. The article talks about how this employee feels he was fired for pointing out flaws in the design of the battery.

At a first glance, it seems to be an interesting discovery. Could this lead to a, "smoking gun" ?

Topic: RE: FAA Grounds 787 Part 3
Username: ikramerica
Posted 2013-01-19 07:47:48 and read 30056 times.

Quoting boacvc10 (Reply 11):

It's the dailykos. Just saying...

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 07:52:59 and read 30008 times.

Quoting JerseyFlyer (Reply 5):
This may have been posted in the locked Parts but Boeing has suspended 787 deliveries.

Like they have a choice.

Quoting JerseyFlyer (Reply 5):
They will need a large parking lot if the grounding is extended for weeks!

I would expect they would be allowed to perform positioning flights to other locations for storage, if necessary.

Topic: RE: FAA Grounds 787 Part 3
Username: tonytifao
Posted 2013-01-19 08:16:40 and read 29826 times.

So is there any idea when the fleet will be back in the air? Can anyone summarize the latest information? Is this as easy as replacing the faulty batteries?

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-19 08:18:04 and read 29805 times.

Quoting airmagnac (Reply 1):
So to summarize, the situation here is not "the plane is unsafe". But rather "the 787 may very well be sufficiently safe, but it may also not be. We just don't know. And until we do know, then it will remain grounded"

Well, no. If we don't know then by default it's not safe enough, hence the grounding. I agree with spacecadet on this one.
The basis for certification is that many kinds of failures can happen, without downing the aircraft. If we now discover failures that were not predicted, all bets are off.

Quoting Daysleeper (Reply 6):
So this is a co-incidence? An aircraft with a history of electrical problems severe enough to cause arcing and fire just happens to have a bad batch of batteries installed causing yet more fires.

Not to defend the 787 but the arcing was determined to have been caused almost certainly by metal shavings, something that could happen anywhere for many reasons (and a modification has been made to minimize the risk).

Topic: RE: FAA Grounds 787 Part 3
Username: PW100
Posted 2013-01-19 08:28:46 and read 29711 times.

Would, could, will, when, if . . . .

Can't we all just agree that in the view of the regulators (FAA, EASA etc), anything supposed to be airborne that has not been demonstrated to be safe, is by definition unsafe? Makes life and these sort of discussions so much easier.

Thanks,
PW100

Topic: RE: FAA Grounds 787 Part 3
Username: _AA_777_MAN
Posted 2013-01-19 09:18:25 and read 29177 times.

I was driving by ORD yesterday and noticed that Lot's 787 is still at ORD. Last I heard they were supposed to ferry it back to WAW on the 17th. Hopefully someone can take some pics.

Topic: RE: FAA Grounds 787 Part 3
Username: Daysleeper
Posted 2013-01-19 09:31:08 and read 28999 times.

Quoting Aesma (Reply 15):
Not to defend the 787 but the arcing was determined to have been caused almost certainly by metal shavings, something that could happen anywhere for many reasons (and a modification has been made to minimize the risk).

I wasn’t aware that it was proven. I know they suspected it could be FOD, but as the firearc would destroy the FOD then it’s presence could only ever be theorised.

Topic: RE: FAA Grounds 787 Part 3
Username: ordwaw
Posted 2013-01-19 09:32:12 and read 28973 times.

Quoting _AA_777_MAN (Reply 17):
I was driving by ORD yesterday and noticed that Lot's 787 is still at ORD.

As far as LO's SP-LRA it is my understanding that there were indications in the cockpit of problems with the Air Conditioning system on the WAW-ORD flight, and the plane would have gone tech anyways - was the problem fixed?

On a similar note ...
Is the QR's 788 (canceled LHR-DOH flight on 1/16) still at LHR or was it ferried back to DOH? Was there ever any explanation as to what caused the cancelation of that flight.

Topic: RE: FAA Grounds 787 Part 3
Username: frmrcapcadet
Posted 2013-01-19 09:39:02 and read 28885 times.

Quoting PW100 (Reply 16):
Can't we all just agree that in the view of the regulators (FAA, EASA etc), anything supposed to be airborne that has not been demonstrated to be safe, is by definition unsafe? Makes life and these sort of discussions so much easier.

It sounds good, it sounds common sense. But as I understand risk management (and the math et cetera they use) the statement does not make sense, and does not help define the steps that need to be taken to ensure safety.

The basic problem is "Anything ... that has not been demonstrated to be safe". In essence it asserts that regulators must prove and demonstrate a negative. You have stated an impossibility.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-19 09:43:05 and read 28832 times.

Quoting airmagnac (Reply 1):
Again, we're in the middle of an interpretation problem, due to the subtlety of english vocabulary (differences between "is", "may be", "could", "is not")

Consider that all releases from manufacturers and regulatory generally go through their legal staff to ensure no absolutes are stated that leave room for law suits.

Scanning the morning news today I noticed some interesting comments.. One there seems to be a shift from the batteries themselves to the charging process and charging rate regulators. Second, it was noted when a battery burns, it usually destroys some of the key components needed for analysis. And third, they are looking at the a/c's extensive computer logs for everything from charging rates to first flickers of warning/informational displays.
Since 90% of the articles rehashed old stuff and boilerplate, and no conclusions were postulated, I didn't bother copying all the URLs.

Topic: RE: FAA Grounds 787 Part 3
Username: PlaneInsomniac
Posted 2013-01-19 09:54:02 and read 28661 times.

Quoting ordwaw (Reply 19):
On a similar note ...
Is the QR's 788 (canceled LHR-DOH flight on 1/16) still at LHR or was it ferried back to DOH? Was there ever any explanation as to what caused the cancelation of that flight.

Like the FAA, EASA has grounded the 787. The Dreamliners are not going anywhere at the moment.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 10:01:42 and read 28589 times.

Quoting PlaneInsomniac (Reply 22):
Like the FAA, EASA has grounded the 787. The Dreamliners are not going anywhere at the moment.

That wasn't the reason for the original cancellation, however. QR stated their was a technical issue that required the plane to overnight at LHR to await parts. QR still operated all other scheduled 787 services that day after the FAA issued the Emergency AD that grounded UA. QR subsequently grounded their flights in accordance with the AD.

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-19 10:44:42 and read 28035 times.

Quoting Aesma (Reply 15):
If we don't know then by default it's not safe enough

I'll be accused of splitting hairs, but once again that is not sufficiently precise  


First, see :

Quoting frmrcapcadet (Reply 20):
The basic problem is "Anything ... that has not been demonstrated to be safe". In essence it asserts that regulators must prove and demonstrate a negative. You have stated an impossibility.

Second, the actions to be undertaken are different if we are talking about :
1) I KNOW the aircraft is not safe
2) I DO NOT KNOW if it is safe, and I have reason to suspect it is not

In the first case you have to take positive action to correct the situation, in this case modify the architecture of the batteries and/or systems around the batteries to prevent any impact on the systems. Which would last weeks or months, cost a lot, and make lots of noise in the media.

In the second case, you take steps to collect and analyse the necessary data. Until then, you consider any scenario is possible, and take the appropriate safety measures to prevent the worst case scenario (which does not necessarily imply grounding, BTW). Notice the "We consider this AD interim action" in the FAA emergency AD. The same formula was also used by EASA in the Emergency ADs about AOA probes on Airbus aircraft a couple months ago
Once you have the info you need, then you now know for sure what the situation is. If you now know for sure the aircraft is unsafe, then go to 1). If it's OK then case closed.


I'm insisting here because I think it's important in order to understand what's going on.

If you understand the current FAA position as "we don't know if the 787 is safe in case of a battery issue, so we're checking", then it does not invalidate previous statements by FAA management of their confidence in the safety of the plane, it does not invalidate the certification process as a whole (it just has to be completed to take into account the new experience).
Also the outcome of the checks could very well be that the 787 is deemed sufficiently safe. In which case, the 787 could be released without a major architecture change, and definitive corrections to the battery issue will come at a later date.

If you understand the current FAA position as "we know the 787 is NOT safe", then that means the FAA is negating all it has done so far with regard to the 787, and FAA management is backpedaling.
And if the plane is released without any major change, then the immediate conclusion is that the FAA is in bed with Boeing, totally corrupt, bla bla bla. And we are already seeing such reactions...


So i'm insisting because such oversimplifications are usually the starting point for all those conspiracy theories, accusations of corruption and compromising of safety etc...
I know this is not the Tech/Ops section, but I think that people on this forum are aware that aviation is complex. And we can therefore avoid oversimplifications.



Quoting kanban (Reply 21):
Consider that all releases from manufacturers and regulatory generally go through their legal staff to ensure no absolutes are stated that leave room for law suits.

I'm sure they don't leave room for legal action, but there is still room for subtly different understandings of the phrasing

Topic: RE: FAA Grounds 787 Part 3
Username: francoflier
Posted 2013-01-19 11:05:17 and read 28334 times.

So it's come down to a semantics battle...

Boy, we really are a bunch of desperate nerds.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 11:13:25 and read 28414 times.

Quoting airmagnac (Reply 24):
I'm insisting here because I think it's important in order to understand what's going on.

And I for one appreciate you making the effort.




I honestly don't know if the situation with the batteries warranted grounding the plane versus requiring airlines to intensively monitor the batteries and charging systems. Yes, fire is bad. Yes, smoke is bad. But at this admittedly early stage of the investigation, neither incident appears to me to have been one that with certainty would have caused a hull loss if it had occurred in a situation that prevented a quick diversion. I may be proven wrong in that belief once the investigation is done. Then again, I may not.

The 737 rudder power control unit. The A330/A340 pitot tubes (both Goodrich and Thales). The cargo door locks on the 747-100. The rear cargo hatch on the DC-10.

All of the above were known issues that could have affected flight safety, and yet the planes were not grounded while the issue was investigated. And I am sure there are more situations that could be brought up.

One can certainly argue "better safe than sorry", but with the above cases, alas we did end up with "sorry" due to the families not being grounded until the issue was fully understood and corrected as accidents happened and lives were lost.

Perhaps because so few 787s were in revenue service, it was an easier decision to order them grounded. Or perhaps the FAA felt stung by past criticism for not taking immediate and definitive action and therefore this time decided they would. Or perhaps the two together.

But as they say, it's air over the wing. The FAA has grounded the 787, compelling everyone else to ground it, as well.

However, I wonder if doing so has helped safety or hindered it, going forward.

Even with the few planes in the air and few ready to be delivered, this grounding is going to cost Boeing a significant amount of money.

If the investigation does uncover a severe error in the design of the 787's battery charging subsystem, then grounding the fleet will hopefully encourage the Regulatory Agencies to ground other planes in the face of what could be a serious safety of flight issue.

But if the investigation shows these were isolated cases caused by bad components (be them the battery or the chargers), then I fear the economic costs to Boeing from the grounding might make regulators around the world less likely to order a grounding in the face of a possibly serious safety issue because if they'e wrong, they've seriously hurt the OEMs.

Topic: RE: FAA Grounds 787 Part 3
Username: francoflier
Posted 2013-01-19 11:25:23 and read 29063 times.

Quoting Stitch (Reply 26):
The 737 rudder power control unit. The A330/A340 pitot tubes (both Goodrich and Thales). The cargo door locks on the 747-100. The rear cargo hatch on the DC-10.

One of the difference between these cases and the 787 issue is the ratio of event numbers / total flight hours for the type.

It is much, much greater in that specific case.

Quoting Stitch (Reply 26):
neither incident appears to me to have been one that with certainty would have caused a hull loss if it had occurred in a situation that prevented a quick diversion.

No certainty, but a largely reasonable amount of doubt. in flight fire is never, ever something where you can say there is no risk of losing the aircraft. Especially when it happens in an inaccessible area with little fire protection/fighting capability.

I personally would have been s#|tting bricks myself if it had happened in the middle of the night halfway across the Pacific...

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-19 11:44:42 and read 28824 times.

Fire protection against a burning li battery is moot anyway. Either the containment keeps the fire under control or not. You would need to cover the battery in dirt or maybe some long lasting foam to extinguish the flames. Both options are not possible for a plane.

Topic: RE: FAA Grounds 787 Part 3
Username: SKGSJULAX
Posted 2013-01-19 11:59:49 and read 28769 times.

Looks like another theory has been advanced by the Japanese investigators:

http://www.flightglobal.com/news/art...na-787-battery-malfunction-381268/

(Apologies if this was posted in the locked thread)

Topic: RE: FAA Grounds 787 Part 3
Username: 7BOEING7
Posted 2013-01-19 12:09:39 and read 28587 times.

Quoting francoflier (Reply 28):
Quoting Stitch (Reply 26):The 737 rudder power control unit. The A330/A340 pitot tubes (both Goodrich and Thales). The cargo door locks on the 747-100. The rear cargo hatch on the DC-10.
One of the difference between these cases and the 787 issue is the ratio of event numbers / total flight hours for the type.

It is much, much greater in that specific case.

Actually at time of the first DC-10 cargo door event there were fewer DC-10's flying than 787's now but it wasn't until the second event on THY that an AD was issued. We don't need to go into the fact that MD new they had issues before the airplane ever flew in passenger service.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-19 12:42:02 and read 28053 times.

Quoting Stitch (Reply 26):
And I for one appreciate you making the effort.

        

I raised the actual wording/meaning of the special conditions in the previous thread, and Cubsrule, airmagnac, Stitch, CM and others took it up. Like it or not, meaning and semantics are critical in a regulatory environment because manufacturers/producers design to meet the precise regulatory requirement, not "near enough", and spend large amounts of money to get there. And as others have pointed out, when the regulatory regime is risk / mathematical probability based, approximate meaning is ... meaningless.

The same issues arise whenever I cite on a.net the wording of international aviation conventions - which often results in accusations of nitpicking. But again, the words are chosen to convey a precise meaning that is understood by the specific target audience (like "fire", "exothermic", "arc", etc for engineers and firefighters). Nobody questions the precise terminology used by medical specialists to convey a specific message to others in the profession. Similarly, the special conditions set for the use of Li-Ion batteries were intended to be understood by the professional engineering risk management and design community to whom they are addressed.

That said, I would not be surprised if one of the outcomes of the FAA review is changes to the conditions.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 12:42:22 and read 28104 times.

Quoting 7BOEING7 (Reply 31):
Actually at time of the first DC-10 cargo door event there were fewer DC-10's flying than 787's now but it wasn't until the second event on THY that an AD was issued.

And that AD didn't ground the fleet, even after the largest loss of life in the history of commercial aviation to that time.

AA96 also happened less than a year after the DC-10's EIS. The JL and NH incidents were over a year after EIS.

And while the FAA is concerned that a battery failure on the 787 could cause a problem with the safety of the plane, there was direct evidence of a problem with the safety of the plane on AA96.

[Edited 2013-01-19 12:44:39]

Topic: RE: FAA Grounds 787 Part 3
Username: rushed
Posted 2013-01-19 12:47:59 and read 27981 times.

Quoting Stitch (Reply 13):


Quoting JerseyFlyer (Reply 5):
This may have been posted in the locked Parts but Boeing has suspended 787 deliveries.

Like they have a choice.

Quoting JerseyFlyer (Reply 5):
They will need a large parking lot if the grounding is extended for weeks!


Interesting point - not much value in delivering a plane the airline can't currently fly. A bit like buying a car and being told you can't have the keys.

I've been following along in the background for a while now - an interesting discussion   I did a quick blog post last night on my take on it all here: http://www.carlousmoochous.com/2013/innews-787-dreamliner-grounding/ (Was going to post the full thing here but it's a bit long). In short, new things, be them airplanes, cars, computers or your phone, have issues when they first launch – that’s how innovation works – you build something, you test the crap out of it, but even after you cover off 99.9% of all bugs, once the consumer gets their hands on it, stuff is going to go wrong, and you need to fix it. We hear so much about this because when something goes wrong with a new airplane the general population and media love it! It’s a high profile story that sells newspapers.

Until the next big plane is launched (eg A350), we will continue to scrutinise the 787 just like we did with the A380 and 777 before it.

Topic: RE: FAA Grounds 787 Part 3
Username: PHX787
Posted 2013-01-19 12:51:05 and read 28056 times.

From Japan Today:
http://www.japantoday.com/category/n...-suspect-excess-voltage-in-battery

Quoting SKGSJULAX (Reply 30):
Looks like another theory has been advanced by the Japanese investigators:

It was in the back of my head too on the other thread.

Let me see if I get this correctly....

Just like when you have a MacBook plugged into the wall while doing homework or whatever, the lithium Ion batteries are being charged by the engine turbines, correct?

And something should keep both the battery in my macbook from overcharging, and same goes with the lithium ion battery...correct?

Well a few weeks back something went wrong with my battery and it would always overheat, eventually bursting its containment and spilling a little bit of the battery material on the wiring that connects the screen to the rest of the computer.... something went wrong with the overcharge safe....just like with these Yuasa battery incidents on the 787, right?

This is just a hypothesis and a layman's comparison.

Also in the other thread which was locked I did bring up that both the JL and NH batteries were apparently from the same line at Yuasa. I wasn't able to confirm any of that using my news sources, was this confirmed by the investigators?

Topic: RE: FAA Grounds 787 Part 3
Username: suseJ772
Posted 2013-01-19 12:56:28 and read 27926 times.

Quoting PHX787 (Reply 35):
ust like when you have a MacBook plugged into the wall

I have had four separate MacBook Pros - all the way from the first version - and I can say that the battery recalls on them have been quite high for this exact reason.

Topic: RE: FAA Grounds 787 Part 3
Username: KarelXWB
Posted 2013-01-19 13:10:13 and read 27662 times.

Quoting rushed (Reply 34):
new things, be them airplanes, cars, computers or your phone,

Or trains, like our beloved Fyra train (sorry, I couldn't resist).

Topic: RE: FAA Grounds 787 Part 3
Username: sweair
Posted 2013-01-19 13:24:01 and read 27532 times.

The thing that surprises me is that so many here think Boeing and FAA did not think of over charging, testing this etc

Do you really think Boeing and the FAA are morons?! If yes, you better take a long look in the mirror..

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 13:42:09 and read 27274 times.

Quoting sweair (Reply 38):
The thing that surprises me is that so many here think Boeing and FAA did not think of over charging, testing this etc.

I fully expect they did.

But if these two batteries failed because they overcharged, why did that happen when the system should have prevented it?

If they failed because they were bad batteries, that should be positive news for Boeing because it implies the charging system in general is sound (since 787s have been charging batteries for over a year without incident). That might be enough to lift the grounding (I would expect in conjunction with regular inspections and testing of batteries).

Topic: RE: FAA Grounds 787 Part 3
Username: KarelXWB
Posted 2013-01-19 13:48:11 and read 27147 times.

Of course they did. Back in 2007 Boeing had to prove the FAA that the use of those batteries were save.

Topic: RE: FAA Grounds 787 Part 3
Username: frmrcapcadet
Posted 2013-01-19 14:04:28 and read 26883 times.

Now to write something in defense of some of the skeptics. We had two NASA Challenger disasters., there are repeated drug and medical devices disasters with items approved by the FDA. In almost all of these cases it did not take hindsight to know things were amiss. NASA ignored engineers. The FDA has somewhat been captured by the industry. Having diabetes I am appalled at the process which has repeatedly approved drugs, promulgated unduly rosy effectiveness. and ignored likely side effects.

There is no evidence that the multiple aviation regulatory agencies around the world have been captured by A or B. In addition there is the macabre reality that if a loved one is to die in an accident hope it is in a plane - the heirs and survivers will almost automatically get a big settlement. The safety record of newer airplanes speaks to the effectiveness of the industry and regulators. I wish that kind of culture would spread to other sectors of the economy.

Topic: RE: FAA Grounds 787 Part 3
Username: RobertS975
Posted 2013-01-19 14:27:38 and read 26576 times.

Quoting _AA_777_MAN (Reply 17):
I was driving by ORD yesterday and noticed that Lot's 787 is still at ORD. Last I heard they were supposed to ferry it back to WAW on the 17th. Hopefully someone can take some pics.

Why bother going back to WAW? It may be necessary to ferry the plane back to the factory for some reworking before it will fly passengers again.

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-19 14:30:36 and read 26534 times.

Quoting airmagnac (Reply 24):
I'll be accused of splitting hairs, but once again that is not sufficiently precise

I don't disagree with what you're saying but I don't see where it contradicts what I'm (and others are) saying.
I have no idea how long the grounding will last or what it will take to get the aircraft into the air again, and I'm not discussing this. I'm only discussing why it was grounded, and the reason is "we don't know so it's not safe".

Quoting Stitch (Reply 32):
And that AD didn't ground the fleet, even after the largest loss of life in the history of commercial aviation to that time.

AA96 also happened less than a year after the DC-10's EIS. The JL and NH incidents were over a year after EIS.

And while the FAA is concerned that a battery failure on the 787 could cause a problem with the safety of the plane, there was direct evidence of a problem with the safety of the plane on AA96.

If we follow your reasoning, either the FAA is more safety oriented now than then (which I would see as a good thing) or the 787 is more dangerous than the DC-10 was.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 14:37:12 and read 26527 times.

Quoting Aesma (Reply 42):
f we follow your reasoning, either the FAA is more safety oriented now than then (which I would see as a good thing) or the 787 is more dangerous than the DC-10 was.

For the moment, at least, the 787 is less dangerous than the DC-10 as it has not suffered an accident, a hull-loss, an injury* or a fatality.

So I guess that means the FAA is more safety-oriented.


* - The injuries at TAK were part of the evacuation.

Topic: RE: FAA Grounds 787 Part 3
Username: ComeAndGo
Posted 2013-01-19 14:38:21 and read 26462 times.

Quoting Stitch (Reply 38):
If they failed because they were bad batteries, that should be positive news for Boeing because it implies the charging system in general is sound (since 787s have been charging batteries for over a year without incident). That might be enough to lift the grounding (I would expect in conjunction with regular inspections and testing of batteries).

The bad battery could still contaminate and potentially damage the electronics bay. How do you know a battery is good or bad ?? The battery has to be safe without contaminating anything, good or bad. So the problem persists.

Topic: RE: FAA Grounds 787 Part 3
Username: planesmart
Posted 2013-01-19 14:42:57 and read 26387 times.

A big part of regulatory safety oversight, are financial indicators.

With prudent oversight and enormous financial penalties for non-compliance, outsourcing approvals to manufacturers is commonsense.

A project which is running behind schedule, or an operator struggling financially, are both situations where outsourcing arrangements should be reviewed, at the very least, resulting in more 3rd party peer reviews, to the other extreme, where it's all brought back inhouse.

This is just a blip, in an industry that has transformed in the last 30-40 years. Passenger and airline confidence will be strengthened by the decisive action taken, and industry and safety authorities will be able to add to their case studies and knowledge base.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-19 14:44:24 and read 26362 times.

Quoting Aesma (Reply 42):
"we don't know so it's not safe"

But "safe" needs to be defined, ultimately. No manufacturer can live with "we can't define safe, but we'll know it when we see it and let you know then".

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-19 15:04:33 and read 26205 times.

Quoting ComeAndGo (Reply 44):
The bad battery could still contaminate and potentially damage the electronics bay. How do you know a battery is good or bad ?? The battery has to be safe without contaminating anything, good or bad. So the problem persists.

        

Zeke has already raised the removal of the APU battery for now. That's pretty easy. For the other battery, stick the container inside another much heavier container that can be pressure sealed.

Topic: RE: FAA Grounds 787 Part 3
Username: BEG2IAH
Posted 2013-01-19 15:12:23 and read 26010 times.

Quoting PW100 (Reply 16):
Would, could, will, when, if . . . .

Can't we all just agree that in the view of the regulators (FAA, EASA etc), anything supposed to be airborne that has not been demonstrated to be safe, is by definition unsafe? Makes life and these sort of discussions so much easier.
Quoting Kaiarahi (Reply 31):
Like it or not, meaning and semantics are critical in a regulatory environment because manufacturers/producers design to meet the precise regulatory requirement, not "near enough", and spend large amounts of money to get there.

In a world of tax accounting and regulations semantics is very well defined and I can't see why it wouldn't be in a far more precise engineering field. Here's how tax regulations define various thresholds of risk:

- Frivolous (below 10% probability);
- Non-frivolous (at least 10%);
- Reasonable basis (at least 15%);
- Realistic possibility of success (at least 33%);
- Substantial authority (objective weighing required; at least 40%);
- More likely than not (>50%);
- Should (at least 70%);
- Will (at least 90%).

Quoting frmrcapcadet (Reply 40):
We had two NASA Challenger disasters

You mean one shuttle (i.e., the whole stack, Challenger) and one orbiter (Columbia)?

Topic: RE: FAA Grounds 787 Part 3
Username: ordwaw
Posted 2013-01-19 15:18:35 and read 26016 times.

Quoting KarelXWB (Reply 39):
Of course they did. Back in 2007 Boeing had to prove the FAA that the use of those batteries were save.

Yet, they modified the design in 2008 to boost their service life. Interesting article from 2008, describing what appears to be last minute design changes, and FAA's overall concerns over the use of lithium ion batteries.

http://chiefio.wordpress.com/2013/01...ithium-batteries-are-not-the-same/

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 15:30:20 and read 25869 times.

Quoting ordwaw (Reply 49):
Yet, they modified the design in 2008 to boost their service life. Interesting article from 2008, describing what appears to be last minute design changes, and FAA's overall concerns over the use of lithium ion batteries.

Interesting to note that the older chemistry, while inherently more volatile than what Boeing swapped for, might have ended up being the safer route because the system was designed and tested implicitly to work with that chemistry.

One wonders the level of howling that would result should Boeing be allowed to return the 787 to service with a battery that contains more volatile chemistry, even if that chemistry is the one that was "proven" through testing.

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-19 15:39:23 and read 25707 times.

Quoting Kaiarahi (Reply 46):
But "safe" needs to be defined, ultimately. No manufacturer can live with "we can't define safe, but we'll know it when we see it and let you know then".

Well, it's a little like that I would think. Lots of experiences made the current regulations what they are, experiences including incidents and accidents. This is precisely why what is happening with the 787 is surprising and unusual.

Topic: RE: FAA Grounds 787 Part 3
Username: airtechy
Posted 2013-01-19 15:49:44 and read 25498 times.

Assuming that the problem is a pair of bad batteries, it brings up the challenge of how you test for the unknown defect that caused the battery to catch on fire. Presumably the batteries are passing an existing test. Having been involved in electronic test.....and design....for years, this could be a real challenge especially if the defect is brought on by environmental conditions or number of charge/discharge cycles. Identifying a defect on what is believed at the moment to be a good battery could be a real challenge.

If there is a tolerance on the amount of charge, I wonder if the problem could be alleviated by reducing the max charge?

The idea of totally sealing the battery box would only create a bomb and will never fly....so to speak.

Based on my experience, I doubt if the battery carcases will yield the cause of the problem. You can bet there are lots of "red team" reviews of batteries and chargers. Been there ... done that!  

Topic: RE: FAA Grounds 787 Part 3
Username: rickabone
Posted 2013-01-19 15:51:48 and read 25461 times.

Quoting ikramerica (Reply 12):
It's the dailykos. Just saying...

A very reputable news organization... Just saying!

Topic: RE: FAA Grounds 787 Part 3
Username: RayChuang
Posted 2013-01-19 15:54:31 and read 25477 times.

From what I've read they have found the culprit: the lithium-ion battery charging system. It appears that the software protocol to recharge the batteries is causing the battery packs to overheat. Hopefully, changing the software and/or changing the computerized systems that manage the battery charging system will fix the problem.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-19 15:59:33 and read 25377 times.

Quoting RayChuang (Reply 54):
From what I've read they have found the culprit: the lithium-ion battery charging system. It appears that the software protocol to recharge the batteries is causing the battery packs to overheat. Hopefully, changing the software and/or changing the computerized systems that manage the battery charging system will fix the problem.

Not wanting to be a pain, but it only fixes the problem of the batteries failing as they have recently. They still need to address the issue of containing a battery adequately when it does fail.

Topic: RE: FAA Grounds 787 Part 3
Username: francoflier
Posted 2013-01-19 16:01:44 and read 25334 times.

Quoting Aesma (Reply 51):
This is precisely why what is happening with the 787 is surprising and unusual.

On the contrary. Based on your accurate statement that safety regulations are based on experiences, good and bad, then an aircraft pioneering new technologies is likely to initially operate in a shady areas of these regulations based only on theoretical knowledge and limited experience. No choice.
And I think they're managing those 'shady areas' much better than they were a few decades ago when they seem to be a lot more cavalier in their approach, as exemplified by the DC-10 mentioned above.

In 10~15 years time the regulations regarding the operation of Li-ion batteries in aircraft will likely have evolved to a level where operational experience will have given them a solid statistical basis.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 16:06:59 and read 25375 times.

Quoting RayChuang (Reply 54):
From what I've read they have found the culprit: the lithium-ion battery charging system. It appears that the software protocol to recharge the batteries is causing the battery packs to overheat.

If that is indeed the culprit, I wonder why have so many 787s flown for so long (four of them for over a year) without the batteries overheating?

There are indeed reports that the two batteries did receive a charge higher than they were designed to take. But the NH bird had been in service a full year prior to the incident. And even with a new battery, it took some three months before the incident manifested itself. The JL bird also flew for a number of months before the battery failed.

At the moment, I remain inclined to believe that the two batteries themselves are the "critical link" in the chain of events that led to the fire on the JL frame and the partial meltdown on the NH frame. However, I am also inclined to believe that they should not have been allowed to become that "critical link" and the entire chain of events needs to be reviewed thoroughly to determine why those batteries could fail and to make adjustments to prevent similarly bad batteries from failing in the future.

Topic: RE: FAA Grounds 787 Part 3
Username: art
Posted 2013-01-19 16:09:05 and read 25307 times.

Quoting RayChuang (Reply 54):
From what I've read they have found the culprit: the lithium-ion battery charging system. It appears that the software protocol to recharge the batteries is causing the battery packs to overheat. Hopefully, changing the software and/or changing the computerized systems that manage the battery charging system will fix the problem.

How long to fix - 2 weeks / 4 weeks / 6 weeks / 8 weeks? Don't suppose it matters THAT much. It's not like the airlines have lost the use of hundreds of aicraft.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-19 16:10:23 and read 25304 times.

Quoting airtechy (Reply 52):

Assuming

the information was the serial numbers were within 30 of each other.. now with only 50 planes flying and another 30 built plus 5 spares at each airline, people could say "oh they were within 200 units" and were should go AHA.. case closed?

Quoting RickNRoll (Reply 55):
Not wanting to be a pain

We have heard you.. unfortunately, A.net is not the designer, regulator, or manufacturer... Time will tell what the final fix is however first is why and how they failed, last is handling the spillage when they do... that said, looking at the volume of excreted material, a larger box is an easy fix.. personally I think a safe pathway for the excreted material is better if as it would get the material away from an ignition source.

Topic: RE: FAA Grounds 787 Part 3
Username: JoeCanuck
Posted 2013-01-19 16:19:20 and read 25153 times.

Quoting Kaiarahi (Reply 31):

Semantics are of key importance in regulations...they are what wins and losses hang on in court.

Quoting frmrcapcadet (Reply 40):
Now to write something in defense of some of the skeptics.

On a practical level, safety is never absolute. In every case, it's a compromise...and not just for airliners. No matter how safe something is, it can still kill. Look at cars...every year, we get more airbags, bigger crumple zones and still people die.

You can't even be 100% safe anywhere. Aircraft makers and regulators decide on levels of safety, based on predictions of reasonable probability and history. They could make an aircraft 99% safe but it would be so heavy it would never get off of the ground. It's a piece of cake to put parachutes on aircraft...but it would cost tens of millions of dollars, making the planes significantly heavier, which means it burns more fuel, can carry fewer people and in the end, it won't be economical. If it can't pay for itself, it will never be purchased so all that safety will never get put into service.

Instead, we have acceptable levels of risk. AF447 could have been saved by parachutes...but it could have also been saved by pushing forward on the stick. I'm willing to bet airlines are training pilots how to better deal with stalls in airliners so that accident may have already prevented more subsequent deaths.

You can't prove something is 100% safe...ever. Everything fails eventually and the more complex, the more things that can go wrong...and Li-ion batteries are both very complex and very nasty if something does go wrong. You can bet these batteries, including their engineering, development and manufacturing, have already undergone intense scrutiny...yet we still got failures. Like the mac batteries and the host of Sony batteries which burned up a lot of computers, it only takes a very small bit of contamination, (microscopic), to get a Li-ion battery to very energetically fail...eventually...provided other conditions are met.

The trick is to predict ever single condition under which a failure can occur. That means everything you know, everything you can think of and everything you don't know and can't think of. Tough sledding, that.

The Sony batteries were found to be contaminated with microscopic bits of metal which eventually caused shorts which cascaded into violent failures. The solution was to spend more time, effort and money on quality control.

My opinion is that these Li-ion batteries, (and batteries of similar chemistry), are unsuitable for high power applications on aircraft. The probability of failure and the difficulty in predicting failures, as well as the violent way they fail, raise them above the level of acceptable risk.

Aircraft have been moving around with batteries forever...as have vehicles of all sorts, and mostly without incident but not these. Even if these batteries are tested for more years, they are now a PR disaster. Fire on an aircraft in flight is just about the most frightening thing ever and even the most ardent fan of flying will give some pause to sitting directly above these batteries, at 41,000 ft.

Until more robust lithium batteries are certified, time to bite the bullet and go with time proven technology. I'm no battery expert, (nor a conspiracy theorist), but I am an electric vehicle enthusiast. I have used many types of batteries and the only ones that ever violently failed while being operated exactly to spec, were li-ion types...and it can be spectacular. I have overcharged, overdrained, shorted and otherwise abused Ni-Cd's, NiMh, and lead acid batteries until they were too hot to hold and never got a fire going. I am using LiFePo4 batteries in electric bikes and giving them some serious abuse as well, and so far, no problems.

The regulatory bodies may once again certify aircraft with these batteries airworthy, but I'm willing to bet you won't find many airlines willing to take another chance with them.

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-19 16:21:02 and read 25118 times.

Quoting francoflier (Reply 56):
On the contrary. Based on your accurate statement that safety regulations are based on experiences, good and bad, then an aircraft pioneering new technologies is likely to initially operate in a shady areas of these regulations based only on theoretical knowledge and limited experience. No choice.
And I think they're managing those 'shady areas' much better than they were a few decades ago when they seem to be a lot more cavalier in their approach, as exemplified by the DC-10 mentioned above.

In 10~15 years time the regulations regarding the operation of Li-ion batteries in aircraft will likely have evolved to a level where operational experience will have given them a solid statistical basis.


While true, I don't remember discussing the batteries before recent events.

If we had to bet on what would go wrong, I doubt the batteries would have made the list. The plastic wings causing trouble was much less surprising.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-19 16:30:07 and read 25130 times.

Quoting kanban (Reply 59):
the information was the serial numbers were within 30 of each other

The S/N of the batteries won't really be meaningful. It is the batch number of the cells within the battery that matters. The way the cells within these batteries are manufactured results in many cells being produced from a single layup of the electrolyte, anode and cathode (produced as a spiral roll, then cut into individual cells). Even very small defects in the layup or cutting process can produce a weakness in the cell that is vulnerable to overcharging, or normal charging after a deep discharge.

The manufacturing process is intended to ensure the quality of the layup and cut. If this has failed and there may be quality escapes into batteries which are installed on 787s, it is conceivable a cell stress test could be developed which would reveal whether or not this weakness exists in any given cell. There are now many reports of Boeing proposing a special test of the batteries as one step toward getting the 787s flying again. If this true, it would not surprise me if a test similar to what I have described above is what is being proposed.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-19 16:51:06 and read 24855 times.

Quoting kanban (Reply 59):
We have heard you.. unfortunately, A.net is not the designer, regulator, or manufacturer... Time will tell what the final fix is however first is why and how they failed, last is handling the spillage when they do... that said, looking at the volume of excreted material, a larger box is an easy fix.. personally I think a safe pathway for the excreted material is better if as it would get the material away from an ignition source.

It is just as important. It will have to be tested and re-certified.

An analogy is ETOPS. A plane is certified for ETOPS 180. During a flight, an engine fails. Instead of being able to fly safely on one engine, it is found that under one engine, the plane cannot handle safely on one engine. This did not show up during testing. The plane is not safe to fly, even if they find the reason for the engine failure was a simple faulty part from a manufacturer. They still have to fix the problem of the plane not handling safely on one engine. They have to redo the testing of one engine handling and rectify and recertify that as well.

Topic: RE: FAA Grounds 787 Part 3
Username: airtechy
Posted 2013-01-19 17:01:13 and read 24742 times.

CM....Interesting. Would you see this as a test run at the spiral level, after it is cut into individual cells, or at the battery level? What sort of defect would be produced and how would it be detected? Inquiring minds want to know.

Jim

Topic: RE: FAA Grounds 787 Part 3
Username: spacecadet
Posted 2013-01-19 17:16:16 and read 24587 times.

Quoting airmagnac (Reply 1):
Again, we're in the middle of an interpretation problem, due to the subtlety of english vocabulary (differences between "is", "may be", "could", "is not")

No, we're actually not. There is no subtlety here. The words and phrasing are very clear - it takes a severe mangling of the English language and the parsing of individual words out of context to interpret it a different way. "Could" and "might" are not the same word, and it seems that some of you are mistaking one for the other. Those two words exist in the English language for a reason. "Could" indicates blanket potential; "might" indicates a binary choice; in other words, it could be one or the other. Don't confuse the two. The FAA used the word "could" intentionally, not "might".

If something *could* affect critical flight systems and structures, then that means there is a safety problem. It's no different than saying the DC-10's cargo door could open in flight, or the 737's rudder could jam. In those cases you could look after the fact and say "well, it did happen, so we know it *could*", but it's the same word with the same meaning. The fact that it *hasn't* happened yet on the 787 is not relevant.

Quote:
Also, you seem to be thinking along the lines of "either it is safe, or it is not".

That is in fact the case. There's no "well, it's *kind* of safe. Therefore it's not not safe". That doesn't mean 787's would be suddenly dropping out of the sky once a week, but there are no "acceptable losses" when it comes to airliner safety. If one 787 crashed because of a known problem over a 20 year span, that doesn't mean it wasn't a safety of flight issue when first discovered - in fact, such an accident would prove beyond a shadow of a doubt that it was! A safety of flight issue is one that has the potential to cause a serious accident. You just can't fly planes with a known potential for damage to critical systems and structures. That's why the plane is not flying.

Again, this isn't coming from me. Just read the FAA statement and try not to twist the words to make things look less serious than they are. The FAA does not certify planes with issues that "could" affect critical flight systems and structures, and the 787 would never have been certified in the first place if this issue had come to light beforehand. And that's because it's a safety of flight issue.

It would also be helpful if some of you would look up the definition of "critical" as the FAA defines it.

This may turn out to be a simple problem, but that doesn't mean it's not a serious one, and a safety of flight problem. The 737's rudder issue turned out to be relatively simple too, and so did the DC-10's cargo door for that matter, but that didn't mean they "couldn't" cause an accident if not corrected.

Topic: RE: FAA Grounds 787 Part 3
Username: KC135Hydraulics
Posted 2013-01-19 17:20:26 and read 24574 times.

Have there been any pictures of the main battery that has failed? I saw pictures of the Boston APU battery but not of the main battery. There are just too many posts to go through on this matter so I'd appreciate it if someone could throw me a bone!

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-19 17:25:14 and read 24542 times.

Quoting KC135Hydraulics (Reply 66):
Have there been any pictures of the main battery that has failed? I saw pictures of the Boston APU battery but not of the main battery.

Yes. They have been posted in a number of the threads on the 787.

Topic: RE: FAA Grounds 787 Part 3
Username: KC135Hydraulics
Posted 2013-01-19 17:30:55 and read 24602 times.

Just found some photos. The battery from ANA looks to have failed very similarly to the battery from JAL! What an eery coincidence these events occured so close to one another in such a similar fashion.

Topic: RE: FAA Grounds 787 Part 3
Username: bonusonus
Posted 2013-01-19 17:39:44 and read 24462 times.

A lot of the latest reports seem to be pointing to overcharging. It's interesting that one failure was in an APU battery and one was in a Main battery. We know that the batteries are identical, but are the charging systems the same as well?

How and when does each type of battery get charged? And how much recharging is typically required in each?

I would think that the APU battery gets recharged from ground power, and needs a substantial percentage. But how about the main battery? Does that charge from engine power in the air? How much energy does the main battery put out during a normal flight (considering it is designed only as a backup in double-engine shutdown situations)?


Finally, it's been mentioned in earlier posts, but, just because overcharging let to the thermal runaway, that doesn't mean that a manufacturer's defect can't also be involved, right? Could these batteries be more susceptible to runaway from a level of overcharging that was within normal design limits?

Topic: RE: FAA Grounds 787 Part 3
Username: KC135Hydraulics
Posted 2013-01-19 17:56:56 and read 24289 times.

From my experience working with aircraft batteries on the 135/17 both batteries are identical in terms of their charging systems. I do believe the main battery gets significantly higher usage/charge during normal ops, however, because there are some electrical components on a battery-direct bus that are powered by the battery at all times, and the battery charger keeps the battery topped off at all times.

On the KC-135, the APU battery is wired only to the two APUs in the back, and its power is only used for starting the APUs and operating the electrical controls (IE, solenoids on the manifolds, the ESCU, etc), and the power usage is small. Also on the KC-135 the APUs are hydraulically started, so you only need the voltage to power a few things.

I would imagine that the APU battery on the 787 sees a very large initial discharge as I assume the battery turns an electrical starter, which to me would require a massive amount of amperage to turn over the APU. If a diesel engine on a Ford truck requires 700+ cranking amps initially, imagine what a large aircraft APU would require.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-19 18:01:25 and read 24239 times.

Quoting KC135Hydraulics (Reply 68):
The battery from ANA looks to have failed very similarly to the battery from JAL!

Lithium cells only have one typical failure mode, that's why they look the same. Overcharge? they get hot, vent, and burn. Short them out? They get hot, vent, and burn. Get them too hot from an external source? Vent and burn. Puncture them? vent and burn. Pretty much any significant lithium cell failure is going to be a molten mess. Most of the other failure modes really aren't visible.

Quoting RickNRoll (Reply 47):
For the other battery, stick the container inside another much heavier container that can be pressure sealed.

And let the pressure build up sky high? the pressure vessel would have to be rated to ensure that it doesn't become a source of high velocity shrapnel when it explodes. No thanks. Now, a sealed enclosure that has fuse plugs similar to the tires (the ones that blow when the tires get too hot, such as due to excessive break heat) that, when blown, vent directly outside the aircraft - that could work. You don't want the cells actually exposed to outside air (too cold) so it can't be a constantly open system, but a sealed box with the only way out being the fuse plugs - that might work.

I am not an engineer, though.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-19 18:05:38 and read 24156 times.

This is a pretty good read on lithium cells:

http://www.mpoweruk.com/lithium_failures.htm

I can't vouch for the information, but at first blush it all looks correct to me.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-19 18:10:39 and read 24192 times.

Quoting spacecadet (Reply 65):
there are no "acceptable losses" when it comes to airliner safety
Quoting spacecadet (Reply 65):
If one 787 crashed because of a known problem over a 20 year span, that doesn't mean it wasn't a safety of flight issue when first discovered - in fact, such an accident would prove beyond a shadow of a doubt that it was!
Quoting spacecadet (Reply 65):
A safety of flight issue is one that has the potential to cause a serious accident
Quoting spacecadet (Reply 65):
that didn't mean they "couldn't" cause an accident

As long as we're asking others to be precise with their words; It's worth pointing out that the actual FAA statement never mentions the word "accident", "catastrophic", "loss of an aircraft", "hull loss" or any other language we typically see applied to concerns about a crash. What the FAA said was:

Quote:
"These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment."

The concern is a fire in the electrical compartment, and damage to critical systems and structures. You can argue the FAA is taking a round-about way of saying it could lead to an accident, but, to be precise, that is not what they said. Furthermore, when the FAA has concerns about specific or catastrophic consequences, they are not shy about saying so...

Quote:
Emergency AD 2010-26-54 "This condition, if not corrected, could result in catastrophic failure of the wing due to disbonding of the wing skin from the wing spar."
Quote:
Emergency AD 2012-26-51 "Blockage of two or three AoA sensors at the same angle may cause the Alpha Prot of the normal law to activate. Under normal flight conditions (in normal law), if the Alpha Prot activates and Mach number increases, the flight control laws order a pitch down of the airplane that the flight crew might not be able to counteract with a side stick deflection, even in the full backward position. This condition, if not corrected, could result in reduced control of the airplane."
Quote:
Emergency AD 2009-07-52 "This condition, if not detected, could result in failure of a bearing, failure of a lever assembly, and subsequent loss of control of the helicopter."
Quote:
Emergency AD 2005-05-52 "Such a wing failure could result in the wing separating from the airplane with consequent loss of control of the airplane."

Don't get me wrong; I'm not diminishing the seriousness of the battery issue. It is just that there are a large group of people here on a.net trying to read the tea leaves and come up with an interpretation of what the FAA is trying to say in the AD. My suggestion is to just take the action and the language of the AD at face value. The action indicates they have a serious safety concern about the batteries on the airplane. The words indicate the concern is a fire in the equipment bay and damage to critical system and structure. That should be enough. It certainly is for me. Let's go fix the problem.

Topic: RE: FAA Grounds 787 Part 3
Username: ADent
Posted 2013-01-19 18:28:45 and read 23936 times.

Quoting RayChuang (Reply 54):
From what I've read they have found the culprit: the lithium-ion battery charging system. It appears that the software protocol to recharge the batteries is causing the battery packs to overheat. Hopefully, changing the software and/or changing the computerized systems that manage the battery charging system will fix the problem.

Typically during a failure investigation you are looking for root cause. It may be the battery charging software. But during the process you will find few/several/many other issues that may/could/probably lead to an accident, just not this one. You address them - some immediately, some soon, some ASAP in the factory.

There will be several changes to the design of the 787 because of this.

Topic: RE: FAA Grounds 787 Part 3
Username: prebennorholm
Posted 2013-01-19 18:35:21 and read 23927 times.

Quoting airtechy (Reply 52):
The idea of totally sealing the battery box would only create a bomb and will never fly....so to speak.

Absolutely correct! A battery box must be vented. And it shall be vented with outflow only out of the plane.

But there is nothing which prevents Boeing to make a system which allows the Li-Ion battery to burn to ashes without any possibility of collateral damage. Then they can demonstrate for the FAA a forced in-flight battery fire, land, exchange the battery container and its contents, and take off again.

No carbon box. No aluminum box. A double wall steel box with heat insulation, please.

It will add some weight. It will take up some underfloor (cargo) space.

And since it wasn't designed that way from the beginning, it will cost some money to redesign, and to remanufacture the present fleet.

It's all about money.

It's nothing new. Double or triple redundant hydraulic systems also add weight, take up space, and cost money.

I will be surprised if FAA re-certifies the 787 with Li-Ion batteries venting its goof in the EE-bay when they fail, as they do today. We can maybe improve reliability, but to ask batteries to never fail, that's like asking the stars not to shine. And the failure mode of Li-Ion batteries it just too nasty to combine in the same environment with other systems.

Maybe they will allow flight temporarily with some extra checks or other operational changes. Simply switching off inflight charging could be one thing. That would reduce the risk, especially if battery temperature check would be included in the preflight checklist. I don't imagine any need to charge the batteries inflight, except maybe faster turn-around times and more APU burn, but I could easily be wrong.

Topic: RE: FAA Grounds 787 Part 3
Username: bonusonus
Posted 2013-01-19 18:47:12 and read 23823 times.

One more battery question. This article says that the batteries are 65 amp-hours each. http://arstechnica.com/business/2013...e-and-yours-may-be-too/?comments=1 But most car batteries are at least 50 amp-hours. It would seem that an airplane requires significantly more power than a car. Is there more to the equation than this?

Topic: RE: FAA Grounds 787 Part 3
Username: prebennorholm
Posted 2013-01-19 19:07:12 and read 23806 times.

Quoting bonusonus (Reply 76):
One more battery question. This article says that the batteries are 65 amp-hours each. http://arstechnica.com/business/2013...e-and-yours-may-be-too/?comments=1 But most car batteries are at least 50 amp-hours. It would seem that an airplane requires significantly more power than a car. Is there more to the equation than this?

Yes, there is more to it.

Car batteries are 12 volt, 14 point something volt under charge.

The same values for the 787 batteries are roughly 29 - 32 volt.

Available power is volt multiplied by amp-hours. So they are roughly three times more powerful than a standard car battery.

My neighbor has a 1951 Ford F100 pickup truck with V8 engine and 6 volt system. It has a 100 amps-hours battery.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-19 19:36:36 and read 23533 times.

I believe that the lithium cells are also capable of delivering many more instaneous amps than a lead-acid pack for a given amp-hour rating. Your typical 50Ah car battery might be able to push say a few hundred amps for tens of seconds, and it will not at all take kindly to repeated treatments like this (short lifespan), I believe the lithium packs on the 787 are far more robust.

[Edited 2013-01-19 19:37:52]

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-19 20:11:52 and read 23250 times.

Quoting CM (Reply 73):
Don't get me wrong; I'm not diminishing the seriousness of the battery issue. It is just that there are a large group of people here on a.net trying to read the tea leaves and come up with an interpretation of what the FAA is trying to say in the AD. My suggestion is to just take the action and the language of the AD at face value. The action indicates they have a serious safety concern about the batteries on the airplane. The words indicate the concern is a fire in the equipment bay and damage to critical system and structure. That should be enough. It certainly is for me. Let's go fix the problem.

What has to be fixed?

Topic: RE: FAA Grounds 787 Part 3
Username: B747forever
Posted 2013-01-19 20:30:56 and read 23167 times.

Where does UA have all their 787s sitting now? I was spotting at LAX today and could see one parked there.

Topic: RE: FAA Grounds 787 Part 3
Username: stasisLAX
Posted 2013-01-19 20:33:33 and read 23201 times.

Quoting SKGSJULAX (Reply 29):
Looks like another theory has been advanced by the Japanese investigators:

Securaplane, the manufacturer of the battery-charging componets in the 787, is based here in Arizona (Oro Valley, Arizona to be exact - near Tucson). Strangely enough, Securaplane's facility burned to the ground after a Li battery fire in a battery assembly area went out of control, burning the entire 12,000 square foot building to the ground. The fire reached 3 alarms and led to an evacuation of residents in the area due to the fumes from the fire.

Source: http://www.tucsonnewsnow.com/global/story.asp?s=5647597

Topic: RE: FAA Grounds 787 Part 3
Username: KC135Hydraulics
Posted 2013-01-19 20:34:37 and read 23180 times.

Quoting nm2582 (Reply 78):
Quoting nm2582 (Reply 78):
I believe that the lithium cells are also capable of delivering many more instaneous amps than a lead-acid pack for a given amp-hour rating. Your typical 50Ah car battery might be able to push say a few hundred amps for tens of seconds, and it will not at all take kindly to repeated treatments like this (short lifespan), I believe the lithium packs on the 787 are far more robust.

If a pickup-sized Diesel engine requires upwards of 700 cranking amps to turn over, imagine the instanteous draw from the electric starter on the 787's APU. It has to be quite high.

Topic: RE: FAA Grounds 787 Part 3
Username: bellancacf
Posted 2013-01-19 20:53:28 and read 23124 times.

Oh Good Grief. What is anyone's take on this?

http://victimsoflaw.net/Leon_Securaplane.htm

Quote: Mr. Leon was forced under threat of termination (March 5. 2007) to ship defective system to aircraft that had a direct short across the failure protection circuitry (fault detection circuitry). He would not ship these parts because they did not match schematics. The system (power converter/ lithium ion battery system) is for the new Boeing 787.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-19 22:09:13 and read 22524 times.

Quoting CM (Reply 62):
The S/N


No argument.. my point was in a small population all serial numbers are close and that may or may not have any significance... I'd be more interested in the Thales controllers. Thanks for your comments from a Boeing retiree

Quoting RickNRoll (Reply 63):
It is just as important.

Where I have trouble with your posts is in the impatience portrayed.. There are many factors to be looked at and with some on they inside (like CM) they can not print anything here that has not been vetted for public consumption. There are also dead ends that if posted and abandoned give conspiracy theorists a hay day. There is also a sequential approach to ensure all aspects are reviewed simulated and tested. It's easy to shotgun.. some managers did that early in the program.. some managers are no longer around.

Topic: RE: FAA Grounds 787 Part 3
Username: Skydrol
Posted 2013-01-19 22:19:38 and read 22497 times.

Quoting stasisLAX (Reply 81):
Securaplane, the manufacturer of the battery-charging componets in the 787, is based here in Arizona (Oro Valley, Arizona to be exact - near Tucson). Strangely enough, Securaplane's facility burned to the ground after a Li battery fire in a battery assembly area went out of control, burning the entire 12,000 square foot building to the ground. The fire reached 3 alarms and led to an evacuation of residents in the area due to the fumes from the fire.


''Investigators say a battery cell exploded and burned in a lab inside the building''
''All employees were evacuated as the fire quickly spread throughout the 10,000 square foot building, which did not have a sprinkler system.''

Sorry to say this (a production facilty and employer burned down), but considering the current B787 situation, the irony is almost laughable.




✈LD4 ✈

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-19 22:20:43 and read 22478 times.

Quoting bellancacf (Reply 83):
Quote: Mr. Leon was forced under threat of termination (March 5. 2007) to ship defective system to aircraft that had a direct short across the failure protection circuitry (fault detection circuitry). He would not ship these parts because they did not match schematics. The system (power converter/ lithium ion battery system) is for the new Boeing 787.

***IF*** this is in fact true, that a safety device was knowingly and willfully bypassed but certified and shipped to Boeing as intact and working, then heads are going to roll.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-19 22:30:09 and read 22380 times.

Quoting bellancacf (Reply 83):
What is anyone's take on this?

It may be unrelated, but it strikes oddly close to the matter at hand. Quotes from a US Department of Labor administrative law judge's decision:

Quote:
Among these products, Securaplane was awarded the contract to design the Battery Charger Unit, or BCU, for the Boeing 787 in approximately 2004.
Quote:
In November 2006, during this transition and growth, Securaplane experienced a devastating fire that destroyed its labs and production building. The fire destroyed records (including many personnel records), upset projects and production, rattled the workforce, and sparked a multi-party root cause analysis investigation that spanned the next two years. The fire ignited when the battery Leon was using to conduct tests on the BCU exploded.
Quote:
Following the fire, beginning in approximately January 2007, Leon claims he began making complaints to his Securaplane supervisors that there were discrepancies between the schematics and assembly documents used in the manufacture of the BCUs and the BCUs themselves. He knew they were shipping the BCUs to customers and the BCUs eventually would go into airplanes. He believed Securaplane would be violating FAA regulations or other federal laws if it shipped what he thought were nonconforming units. He says he was pressured to sign off on Acceptance Test Procedures (ATPs)7 for noncompliant units and ship them to customers. He says he gave in to pressure to run the ATPs, knowing they would be re-run after he fixed the units, but balked at actually shipping noncompliant units. On March 1, 2007, he left work without shipping what he thought were noncompliant BCUs, and when he returned to work on March 5, 2007, he received a formal written disciplinary warning. Leon says he continued to raise the nonconformance issues and the discrepancy, but no one fixed it. Eventually he filed an FAA complaint. Meanwhile he was subject to additional discipline including a Performance Improvement Plan (PIP). He was later suspended, and eventually fired. Leon believes the timing of his termination proves Securaplane was motivated by retaliatory animus towards Leon‘s protected safety activities.

The decision goes on and on into great detail about issues raised concerning the BCU. There is no smoking gun that I could tell, but this Michael Leon guy was a high caliber of Prima Donna, that's for sure.

Topic: RE: FAA Grounds 787 Part 3
Username: flood
Posted 2013-01-19 22:37:03 and read 22431 times.

Quoting stasisLAX (Reply 81):
Securaplane, the manufacturer of the battery-charging componets in the 787

Looks like the NTSB is heading down there on Tuesday.

Ostrower just tweeted:

- NTSB Says Battery That Caught Fire On JAL Boeing 787 Didn't Exceed Design Voltage
- NTSB Investigators Have Analyzed Black Box Data From Boeing 787 Fire In Boston
- NTSB-Led Team To Examine And Test 787 Battery Charger In Arizona Tuesday

Quoting B747forever (Reply 80):
Where does UA have all their 787s sitting now? I was spotting at LAX today and could see one parked there.

As far as I know, 1x LAX, 1x NRT, 4x IAH.

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-19 23:31:48 and read 22096 times.

Good evening folks, first-time poster, etc. First, full disclosure: I'm an ex-Boeing employee; worked there for 11 years. However, I did not work for the commercial airplanes division.

I've seen several posts asking how the FAA defines "safe". For commercial aircraft, Advisory Circular 25.1309 quantifies the level of risk that must be achieved for different categories of failures. Failures are categorized depending how severe the foreseeable consequences of the failure is. If we assume that the most severe reasonable consequence of the batter fire would be hull loss and/or loss of life, that meets the definition of "catastrophic", which is the most severe category.

Catastrophic failures most be reduced to a probability of less than 10^-9 per flight hour. You figure that up by using a fault tree, which diagrams all of the faults that must occur in order to bring about the failure. You start with the 10^-9 at the top of the tree, and then you allocate it across the failure mitigations and design redundancies. For example, if you have two subsystems which will cause a catastrophic failure if they both fault, then you might assign a probability level of 10^-4 to one and 10^-5 to the other. You then go further down the tree, breaking it down into individual components (to the extent that you can). For a lot of individual electrical and mechanical components, historical fault rates are fairly well established and you can work out the top-level failure probability with a high degree of confidence.

You run into problems when you have a new-technology component like these batteries, because there isn't enough data to establish a fault rate with a high degree of confidence. You can use data from other applications (e.g., automotive), but that other application might not use the components in the same way. Or you can do accelerated-aging testing, but that might not be capable of duplicating all of the conditions encountered in flight. So you do the best you can with what you have, and hope there aren't any unknown unknowns.

One thing that remains to be seen is whether there is a previously unidentified risk (an unknown unknown) at work with these batteries. Does the aviation application trigger a previously unobserved failure mode? Otherwise, we run into the matter of why the presumably multiple layers of redundancy present in the subsystem are not preventing the failure. When you have multiple layers of redundancy failing, you of course start by looking for a common factor that was missed in the fault tree analysis. Such a common factor "short circuits" the fault tree -- it effectively takes the multiple layers of redundancy out of the analysis, and ties the higher-level probability directly to the occurrence probability of the common factor. That's nearly always a bad thing, and when you find them during analysis, you have to do something to break the common factor up. A good example of a common factor that was missed is shown by the Iowa City DC-10 crash a few years ago. There were four redundant hydraulic loops for actuation of the aircraft's control surfaces. But they were all routed through the upper rear fuselage near the center engine. And when the center engine suffered an uncontained failure, that became a common factor that faulted all four hydraulic loops and resulted in the catastrophic event of complete loss of pitch and roll control.

And in case you were wondering, there's another Advisory Circular, 23.1309, which defines acceptable levels of risk for general aviation aircraft. As you might guess, small aircraft which are not high-performance, seldom used in revenue service, and don't have complex systems are allocated levels of risk which are somewhat less stringent.

Topic: RE: FAA Grounds 787 Part 3
Username: sweair
Posted 2013-01-20 00:52:01 and read 21192 times.

So to repeat my question, would or could a fuel cell fueled by Jet-A be safer than a battery? They create heat, but has there been any serious incidents with fuel cells?

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-20 01:02:21 and read 21052 times.

Quoting kanban (Reply 84):
Where I have trouble with your posts is in the impatience portrayed.. There are many factors to be looked at and with some on they inside (like CM) they can not print anything here that has not been vetted for public consumption. There are also dead ends that if posted and abandoned give conspiracy theorists a hay day. There is also a sequential approach to ensure all aspects are reviewed simulated and tested. It's easy to shotgun.. some managers did that early in the program.. some managers are no longer around.

They are two distinct aspects of the problem, which both need to be solved. Solving either one alone is not enough.

1) Preventing a battery failing
2) Coping with a battery failing.

Topic: RE: FAA Grounds 787 Part 3
Username: packsonflight
Posted 2013-01-20 02:10:52 and read 20399 times.

Quoting RickNRoll (Reply 91):
They are two distinct aspects of the problem, which both need to be solved. Solving either one alone is not enough.

1) Preventing a battery failing
2) Coping with a battery failing.

You are spot on!

This really boils down to three main points:

The batteries are flawed, and then the manufacturer has to make a correction, but in that case we could see some kind of test to verify if the batteries are good or bad and the 787 could be flying soon.

The charging/discharging system does not work as designed, and then Boeing has to make some changes and get the FAA to approve them. Considerable time needed.

The 787 did not contain the battery failure properly. As far as I can see this is a fact, and Boeing definitely have to make some hardware changes here and get them certified.

Topic: RE: FAA Grounds 787 Part 3
Username: art
Posted 2013-01-20 03:23:52 and read 19942 times.

Quoting bellancacf (Reply 83):
Oh Good Grief. What is anyone's take on this?

http://victimsoflaw.net/Leon_Securap...e.htm

"Mr. Leon was forced under threat of termination (March 5. 2007) to ship defective system to aircraft that had a direct short across the failure protection circuitry (fault detection circuitry). He would not ship these parts because they did not match schematics. The system (power converter/ lithium ion battery system) is for the new Boeing 787."

Don't know if that is true but if it is true that Mr Leon was forced to ship a defective battery, that's commercial interest overiding safety interest to me or perhaps an employer/employee dispute overiding safety interest. Would such an action not breach the QC procedures required for the battery supplier to retain its ISO rating (or local equivalent) without which it would not be an authorised supplier?

Topic: RE: FAA Grounds 787 Part 3
Username: B2319
Posted 2013-01-20 03:38:16 and read 19860 times.

All,

My first post on a-net after a long-time lurker. I've an important point to raise a little bit later, however, let me make some general points:

On this thread, I've never seen so much drivel posted in a public place. In my native dialect, this is a four letter word that ryhmes with wish and starts with a 'p'. This is in complete contrast to this thread A350 Prototypes Production Thread Part 6 (by ManuCH Nov 8 2012 in Civil Aviation) where the overall quality is so much better...... (Joke: First post on a-net and inadvertently started an A vs. B war..... (Actually, no- the linked thread has superb contributions from fanboys (of both colours) and non-fanboys alike)). Now, this thread has some great input, a handful of you, and I don't want to name anyone for risk of omitting one. However, you know who you are.....  

Also, tempted to post elsewhere, e.g. new Beijing airport thread, where some people way off the mark regarding China and its ability to implement infrastructure projects. Is the 787 programme an infrastructure project? Well, there's enough semantics on this thread, so, another joke, folks.

However, my main point is more of a question. Over 500 posts in and nobody has mentioned this so far: China hasn't certified the 787 and there are units sat on the ground in the USA because of this. Can people have a think about the significance of this?

A crude observation is that China throws its not-insignificant resources in order to progress projects and solve issues. So, why not in this case? I'm sure there's a reason for this, and I do not want to make a political point, especially on my first post. So, I'll stick to crude jokes. On the 787 Deliveries thread, there's a comment from a user who puts a '   ' next to the fact that CAAC certification will be at March 2013, at the earliest. You can trawl (not troll) through that thread for the offending person.......

Anyway, that's my point made. Looking forward to the dabates and challanging the 'bad science' that is contaminating this thread, and others. After I return from the pub.....!

Cheers

B-2319

Topic: RE: FAA Grounds 787 Part 3
Username: packsonflight
Posted 2013-01-20 03:56:20 and read 19700 times.

Quoting bellancacf (Reply 83):
Quote: Mr. Leon was forced under threat of termination (March 5. 2007) to ship defective system to aircraft that had a direct short across the failure protection circuitry (fault detection circuitry). He would not ship these parts because they did not match schematics. The system (power converter/ lithium ion battery system) is for the new Boeing 787.

Possibly another Koito industry (The defect aircraft seats) scandal unfolding here.......

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-20 04:10:52 and read 19610 times.

Quoting RickNRoll (Reply 91):
They are two distinct aspects of the problem, which both need to be solved. Solving either one alone is not enough.

1) Preventing a battery failing
2) Coping with a battery failing.

I suggest you read post 89 (just 2 before yours) carefully and think about fault trees. You may also wish to note that the regulatory conditions for use of Li-Ion batteries do not require them to be fail-proof. With that in mind, you may wish to again read post 89 and think carefully about fault trees.

Quoting CM (Reply 73):
As long as we're asking others to be precise with their words

  

Topic: RE: FAA Grounds 787 Part 3
Username: wjcandee
Posted 2013-01-20 04:15:19 and read 19590 times.

This Leon whistleblower thing is a sideshow. What is quoted in the previous post [reply 93] is the allegations by Leon, who represented himself, rather than the finding. (By representing himself, Leon had a greater opportunity to display his personality to the judge than would have been the case had he sat at the table and let his lawyer do the questioning, arguing, etc.; accordingly, the judge got to view first-hand what Leon's co-workers and employer were complaining about personality-wise.)

The well-thought-out opinion by the Adminstrative Law Judge who heard the case in a 4-day trial has a number of interesting points.

Leon was found to be an intemperate, argumentative person who scared many of his coworkers. He was a tech who was good at diagnosing problems in individual components, and the company had bent over backwards to try to keep him because his work was good, even though he screamed at supervisors, threw things, walked off the job, etc. Numerous coworkers thought he might harm them and complained. Finally, the employer had had enough and canned him.

The "nonconforming" products which he allegedly "refused to ship" were not production sets of the charger for use in aircraft. This happened at a much earlier stage in design and testing. The total planned time to design and test the charger was SEVEN YEARS and this happened a couple of years in. What was being shipped then were "red tagged" prototypes of the charger for various stakeholders to test and to use to see how they integrated with other components in the overall battery power system. None of these would ever be getting on a plane, except for very specific tests, and never on a passenger version.

The alleged nonconformity was that the then-current revision of the design drawing described a circuit that was slightly-different from the circuit in the production drawing. Both were regularly revised to reflect engineering changes based on experience with the prototypes, and the production drawing was in fact correct. However, the design drawing should have been revised to reflect reality, and it was once Leon brought his complaint forward. In his mind, if the production drawing was different from the design drawing, then anything produced under the latter was "nonconforming" and that was his beef. Also, one revision of the design drawing may have had essentially a typo in it (a "draw-o"?) that was a material mistake made when they tried to turn engineering instructions into a drawing -- it may have reflected a short-circuit. Interestingly, the PhD who designed the circuit went from being a fan of Leon's to being someone who no longer wanted to work with him when he discovered that Leon had discovered the errors about 4 months prior to bringing them forward. He was angry not that the mistake had been found but rather that Leon hadn't brought it immediately to his attention so it could be fixed, which it was. That same PhD later had some concerns about whether Leon had intentionally or recklessly caused the battery explosion and resulting fire that destroyed the company's headquarters. From the other evidence, including that Leon was truly distraught about the fire and had helped try to put the battery out and was upset that he wasn't able to get it out of the building, this was probably an unfounded concern.

The opinion contains some very interesting descriptions, including of the battery itself, which show what an amazingly-complex system this is -- far beyond what I had envisioned, and far beyond what anyone in the media or on here, other than the real engineers, seem to understand.

Here's how the battery and charger are described:
"Two groups at Securaplane were assigned to use a specially made lithium ion battery, the Starting Power Use (SPU) group and the BCU [battery charger unit] group with which Leon worked. The battery weighed about 50 pounds, was approximately twice the size of a car battery, and was considered the Ferrari of batteries because it was lightweight and powerful. It had a signal connector made to connect with the BCU with roughly 20 to 30 interface signals that go between the two. The BCU was designed to recharge the battery once it had been drained,

The company had this version of the battery from Yuasa, and they had an accident with it prior to the fire:

In June 2006, the SPU group had an accident with the lithium ion battery. When the technician removed the ground power supply connections, he accidentally connected the connections on the battery harness to the capacitor bank rather than the input contactor and the SPU power return directly. Then when he tried to connect the power plug into the power receptacle on the Li-Ion battery the terminals saw a temporary short circuit into the cap bank and arced to each other. The power plug was immediately removed and the damage assessed. The technician opened up the battery to replace the power connector with a new connector. During the change out, the bus bars were moved to a position that shorted the battery cells to the case. This happened very quickly and they were moved to remove the short. Securaplane manager Curtis Brown documented the accident, including photographs of the damage and reported it to GS Yuasa, the Japanese company that built the battery, and Thales, the French company for which Securaplane was designing and manufacturing the BCU, which would eventually be sed in the Boeing 787. GS Yuasa and Thales employees exchanged several emails with Securaplane discussing the damage, testing cell voltages, and determining if the battery was safe to use. Brown explained he wished to continue using the battery for SPU testing and BCU charging. GS Yuasa concluded there should be no problem with the battery, instructed Securaplane to monitor the battery temperature and appearance during testing and not use it in an unmanned lab. GS Yuasa sent an email explaining they‘d analyzed the battery data and didn‘t think it posed a problem.

Leon thought the battery prototype, because it had been in an accident, wasn't fully-safe to use, and, when later using it himself months later, caused it to ignite and explode and burn down the administration building. Securaplane, along with Boeing, Yuasa, and others conducted a root cause analysis that took two years to complete, and don't appear to have reached a definitive conclusion about the cause of the fire, although the fact that Leon wasn't using the signalling harness on the battery when it went up may have contributed, as the charger (and he) couldn't monitor the battery condition while charging.

The thing is a worthy read that really highlights the complexity of the system, the battery, etc. This plainly isn't just a car battery or an iphone battery, nor is the equipment which charges it.

[Edited 2013-01-20 04:50:56]

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-20 04:21:59 and read 19477 times.

Quoting wjcandee (Reply 97):

Thank you.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-20 04:27:20 and read 19463 times.

Quoting Kaiarahi (Reply 96):
I suggest you read post 89 (just 2 before yours) carefully and think about fault trees. You may also wish to note that the regulatory conditions for use of Li-Ion batteries do not require them to be fail-proof. With that in mind, you may wish to again read post 89 and think carefully about fault trees.

If we solved one perfectly, we would not need two. Obviously, we do. What I meant was fixing the current reason for them failing. Overcharging, spikes on the power distribution circuit, faulty manufacturing, whatever. The FAA will want to know why the current batteries failed, and that it has been rectified. It also wants to know if, when a battery does fail in the future, as they will, but much more rarely, that there is a means of containing what results (with the current set of failures) if they do fail.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-20 05:37:12 and read 19093 times.

Quoting SKGSJULAX (Reply 29):
Looks like another theory has been advanced by the Japanese investigators:

http://www.flightglobal.com/news/art...1268/

Overcharging is serious

Quoting sweair (Reply 37):
The thing that surprises me is that so many here think Boeing and FAA did not think of over charging, testing this etc

Do you really think Boeing and the FAA are morons?!

Yes, they did think of overcharging. But they did not consider it to happen. In fact the FAA asked for a solution that would rule it out.

The regulatory requirements (no excessive heat increase of any cell during charging) means nothing else, that overcharging would never be a condition of this batteries. Because when overcharged, any lipo battery will hurt that requirement:
http://www.youtube.com/watch?v=EseOhC8n7ro

So the system had always to guarantee safe cell temperatures during charging. As this requirement seems to have been broken, the grounding is a logical decision.

Quoting Stitch (Reply 38):
If they failed because they were bad batteries, that should be positive news for Boeing because it implies the charging system in general is sound (since 787s have been charging batteries for over a year without incident).

No, the charging system has to consider battery aging during charging. In a real lipo battery each cell of the battery behaves differently over time. Therefore the charging system needs to monitor the voltage on each cell seprately and apply differential charging currents, to maintain a very strict voltage balance over each cell. If this is not done, the total voltage over all the cells in serie might not indicated the slightest problem, while a single cell is quitly dying (before exploding).

What I do wonder, is whether having only a small number of high capacity cells (8 IIRC) has contributed to the troubles. That means that a single cell is quite large. Because of these extensive dimensions the consequence could be, that not the whole cell would start charging and discharging homogeneously. Could there have been local "overcharged" areas in a single cell? Just an educated guess...

Topic: RE: FAA Grounds 787 Part 3
Username: jreuschl
Posted 2013-01-20 06:25:33 and read 18863 times.

http://bit.ly/13RLGvi.

Apparently Boeing didn't like the grounding at all. Not a good reaction. Did they not think at the very least they had a bad batch of batteries that needed replacement?

Topic: RE: FAA Grounds 787 Part 3
Username: nomadd22
Posted 2013-01-20 07:27:00 and read 18576 times.

Quoting rheinwaldner (Reply 100):
No, the charging system has to consider battery aging during charging. In a real lipo battery each cell of the battery behaves differently over time. Therefore the charging system needs to monitor the voltage on each cell seprately and apply differential charging currents, to maintain a very strict voltage balance over each cell. If this is not done, the total voltage over all the cells in serie might not indicated the slightest problem, while a single cell is quitly dying (before exploding).

That's the best way to do it. It's how Tesla handles their packs. All chemistries have that same problem, where a bad cell in a seires starts climbing in voltage while charging, which doesn't show up on the total voltage reading for the series. Usually, even if you don't have individual cell monitoring, a simple thermistor type device will cut off charging current when the temperature starts climbing. But a Lithium cell can take off before that happens if the pack is poorly designed or manufactured.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-20 08:28:30 and read 18246 times.

Quoting B2319 (Reply 94):
China hasn't certified the 787 and there are units sat on the ground in the USA because of this. Can people have a think about the significance of this?

Before the JL and NH incidents, Boeing had pulled some of the Chinese carrier frames out of storage and were performing flight tests on them. So there was hope that CAAC was going to issue certification and allow the planes to be delivered. The grounding, of course, has put those on hold.

As to why CAAC had not certified the 787, one theory put forward is that CAAC wanted the FAA to relax the certification rules for the COMAC ARJ21 and C919 and was holding up the 787 to apply pressure. Personally, I don't give that theory any credibility.

Topic: RE: FAA Grounds 787 Part 3
Username: frmrcapcadet
Posted 2013-01-20 08:38:02 and read 18072 times.

Quoting cornutt (Reply 89):
Good evening folks, first-time poster, etc. First, full disclosure: I'm an ex-Boeing employee; worked there for 11 years. However, I did not work for the commercial airplanes division
Quoting wjcandee (Reply 97):
The thing is a worthy read that really highlights the complexity of the system, the battery, etc. This plainly isn't just a car battery or an iphone battery, nor is the equipment which charges it.

Found it useful reading these posts.

Topic: RE: FAA Grounds 787 Part 3
Username: B747forever
Posted 2013-01-20 08:48:18 and read 17985 times.

Quoting flood (Reply 88):

As far as I know, 1x LAX, 1x NRT, 4x IAH.

So that bird never left NRT before the grounding.

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-20 09:42:36 and read 17533 times.

Quoting RickNRoll (Reply 99):
It also wants to know if, when a battery does fail in the future, as they will, but much more rarely, that there is a means of containing what results (with the current set of failures) if they do fail.

That's the preferable way to do it, but it isn't always possible. For example, there is no known technology to contain a vapor explosion in a fuel tank. So what you do, to meet the certification standard, is design the systems to minimize the possibility of a fuel tank explosion from happening. I don't know how much energy is involved in these battery failures, but minimizing the possibility of the failure might be a more practical approach than trying to contain it. As long as the probability of the hazard is reduced to less than the 10^-9 standard, either approach is acceptable from the certification standpoint.

Topic: RE: FAA Grounds 787 Part 3
Username: 7BOEING7
Posted 2013-01-20 09:57:25 and read 17412 times.

Quoting B747forever (Reply 105):
So that bird never left NRT before the grounding.

I believe it was inbound at the time.

Topic: RE: FAA Grounds 787 Part 3
Username: Newark727
Posted 2013-01-20 10:29:35 and read 17135 times.

Apologies if this has been asked and answered before, but what are the plans of NH and JL for the routes they've started that have only ever used the 787? BOS, SAN, SJC, maybe others? So far all I've seen is a bunch of cancelled flights, would they ever consider some kind of equipment substitution or what?

Topic: RE: FAA Grounds 787 Part 3
Username: PHX787
Posted 2013-01-20 10:33:17 and read 17222 times.

Japan Today, Yomiuri, and AvHerald all saying one thing about ship 829 (BOS)- apparently the resulting fire near the APU was NOT the result of an overcharge.

I'm having issues getting Japan Today to post and of course Yomiuri is in Japanese, so here is the article from the AvHerald:

http://avherald.com/h?article=45c377c5&opt=1

Quote:
The NTSB reported on Jan 20th 2013 that a first examination of the flight data recorder of JA829J showed the nominal battery voltage of 32V has never been exceeded.

However, Yomiuri and other reports from Yuasa's probe are also saying that the incident in TAK could possibly very well be from an over charge, as we have previously established.


Well we have two very different cases now on our hands, and these reports surely aren't going to make the FAA lift the A.D. anytime soon, in my opinion.

Quoting jreuschl (Reply 101):
Apparently Boeing didn't like the grounding at all. Not a good reaction. Did they not think at the very least they had a bad batch of batteries that needed replacement?

Well if I was a multi-national corporation whose livelyhood stood on the success of this huge investment, I wouldn't be happy about it too.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-20 10:34:04 and read 17167 times.

per http://avherald.com/h?article=45c377c5&opt=6144

The NTSB reported on Jan 20th 2013 that a first examination of the flight data recorder of JA829J showed the nominal battery voltage of 32V has never been exceeded. The battery, powering the APU for APU startup, has been disassembled into its 8 cells for detailed examination and documentation, 3 of the cells were selected for further disassembly and examination of cell internal components.

Rickandroll... continually repeating yourself will not make things happen faster.. nor will getting 9 women pregnant produce a baby in a month.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-20 10:47:13 and read 17013 times.

Quoting cornutt (Reply 106):
I don't know how much energy is involved in these battery failures

That much is easy. 32V x 65Ah = 7.5 megajoules

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-20 10:57:51 and read 16914 times.

Quoting WingedMigrator (Reply 111):
Quoting cornutt (Reply 106):
I don't know how much energy is involved in these battery failures

That much is easy. 32V x 65Ah = 7.5 megajoules

I think he meant the energy released by the cells letting go.

Topic: RE: FAA Grounds 787 Part 3
Username: teme82
Posted 2013-01-20 10:59:13 and read 16907 times.

Quoting WingedMigrator (Reply 111):
That much is easy. 32V x 65Ah = 7.5 megajoules

I think that is more than enough to cause serious issues with the aircraft. If all the batteries would fail at the same time it would be really bad day for that plane and it's occupants.

Topic: RE: FAA Grounds 787 Part 3
Username: gigneil
Posted 2013-01-20 11:06:08 and read 16860 times.

Quoting nomadd22 (Reply 102):
It's how Tesla handles their packs.

Totally off topic, but Tesla should design everything everywhere all the time, I think.

The level of technology sharing between Tesla and SpaceX is high, as well.

I wonder if Tesla could in fact handle producing sufficient batteries for this application?

Wishful thinking of course.

NS

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-20 11:14:24 and read 16798 times.

Quoting kanban (Reply 110):
Rickandroll... continually repeating yourself will not make things happen faster.. nor will getting 9 women pregnant produce a baby in a month.

   Has that been tested?

Especially since it took 7 years to design and test the BCU - maybe not continuous effort, but still ....

Topic: RE: FAA Grounds 787 Part 3
Username: F9animal
Posted 2013-01-20 11:20:31 and read 16772 times.

The plane is grounded because it is not safe. A fire from a battery is dangerous. Stop downplaying it, because it is what it is. We can try to word it as possible, maybe, could.... But, the FAA grounds planes when they are NOT safe. We can call these arcs, shorts, and non fires... But... They shot flames, and if you can roast marshmallows on a flame, the flame is a fire. These groundings were not because of "minor" incidents. These are serious incidents, warranting a grounding of the airplane. Not just dangerous, but very dangerous to breathe those toxins.

Topic: RE: FAA Grounds 787 Part 3
Username: gigneil
Posted 2013-01-20 11:30:10 and read 16648 times.

The toxins cannot get into the cabin from where they are, but that's another really related to this.

NS

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-20 11:36:16 and read 16611 times.

Quoting F9animal (Reply 116):
But, the FAA grounds planes when they are NOT safe.

Given the length of time that has passed since a grounding, I don't know how it's possible to make any sort of categorical statement about when FAA does or does not ground planes. That's particularly true given the political/regulatory environment the current administration has created for manufacturers (see, e.g., the Toyota mess in 2009 and 2010, complete with Ray LaHood going on TV and telling people not to drive their Toyotas).

Topic: RE: FAA Grounds 787 Part 3
Username: mke717spotter
Posted 2013-01-20 11:36:40 and read 16614 times.

Not sure if anyone has mentioned this yet, but is LO's 787 still at ORD or has it been ferried back to WAW yet?

Topic: RE: FAA Grounds 787 Part 3
Username: gigneil
Posted 2013-01-20 11:42:11 and read 16554 times.

It can't be ferried, it doesn't presently have the legal ability to fly.

NS

Topic: RE: FAA Grounds 787 Part 3
Username: ordwaw
Posted 2013-01-20 11:43:18 and read 16557 times.

Quoting _AA_777_MAN (Reply 17):

Due to EASA following FAA, no EU registered 787s planes can fly. So SP-LRA is still at ORD.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-20 12:17:00 and read 16286 times.

Quoting kanban (Reply 110):
The NTSB reported on Jan 20th 2013 that a first examination of the flight data recorder of JA829J showed the nominal battery voltage of 32V has never been exceeded. The battery, powering the APU for APU startup, has been disassembled into its 8 cells for detailed examination and documentation, 3 of the cells were selected for further disassembly and examination of cell internal components.


Ok, so an 8 cell pack with 32v as the "never exceed" value: we can assume this pack is simply 8 cells in series; and that Boeing has chosen to set 4V per cell as the maximum (the cells last longer this way than taking them up to the absolute max 4.2V).

I *hope* that there is a lot more to it than the NTSB reported, though. You MUST monitor the individual cell voltages, overall pack voltage is NOT enough (it's practically useless). If you don't monitor individual cell voltages, here's what can happen:

Let's say you have a pack of 8 cells, and one of the cells (for whatever reason) experiences a loss of capacity - that is, the amount of energy it can store is not as much as it should be. It's still "safe" in that it's not hot, it's not on fire, etc.; and it still acts like a lithium cell (it's voltage output is the same and it's safe operating parameters are the same) it just can't accept the amount of energy that it used to. If it was rated as a 65Ah cell, maybe it's capacity is now 30Ah.

So then, we have 8 cells in series, 7 of which have full 65Ah capacity, and one of which is now 30Ah. Now let's charge this pack, lets assume that the pack is completely "dead" (3.0 volts per cell) and let's say we charge it with 65 amps of current. The battery SHOULD fully charge in about an hour - if all the cells were 65Ah capacity. But they aren't. The cell which has degraded to 30Ah absorbs it's maximum amount of energy (hitting 4.2v) well before the other 7 cells (perhaps they are all still at 3.8v). 7 cells at 3.8 volts plus 1 cell at 4.2 volts only registers 30.8 volts, so everything looks fine (it's below the 32v max); but if you keep putting power into the pack, the one cell which is at 4.2 volts is going to continue to rise in voltage at a fairly brisk rate and WILL fail.

Again, that's what can happen IF you don't monitor individual cell voltages.

I sincerely hope the NTSB is "dumbing down" what they report, and that in fact the charger design prevents the possibility of the above scenario.

There are successful ways to combat the above scenario: You can charge each cell individually with it's own dedicated charge circuit (best way but complex, requires charging outputs with non-common ground, more expensive/complex). You can charge the pack as a whole (apply charge current at the +/- terminals of the entire pack) but have monitoring on each cell which imposes a drain (resistance) on individual cells to control the cell voltage, with the goal being that when the charge current stops, all cells are at identical voltage. The problem with this approach is that chargers often have a limit on how much current they can drain from each individual cell, which means that there is a limit to how much of a capacity mismatch between cells they can cope with.

Topic: RE: FAA Grounds 787 Part 3
Username: gemuser
Posted 2013-01-20 12:18:38 and read 16266 times.

Quoting gigneil (Reply 120):
It can't be ferried, it doesn't presently have the legal ability to fly.
Quoting gigneil (Reply 120):
Due to EASA following FAA, no EU registered 787s planes can fly. So SP-LRA is still at ORD.

Actually this is not true. The relevant National Airworthiness Authority (NAA) COULD issue a Ferry Permit to enable the aircraft to return to its base or to another MRO. In this particular case it would also need agreement from all the NAAs under the flight path, which is theoretically possible, but undoubtedly a major P-in-A.
Obviously LOT & EASA do not think this is necessary, at this point in time.

Gemuser

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-20 12:31:03 and read 16123 times.

Quoting F9animal (Reply 116):
the FAA grounds planes when they are NOT safe

It does, but not even the FAA knows that yet - that's why there is an investigation and review. It also sometimes grounds planes when they may not meet design or production certification requirements or the certifications may require review.

There's probably little point in trying to demonstrate nuance to someone who sees everything in layman's absolutes, and apparently doesn't believe that the precise language used by regulators and engineers has a precise meaning, but if you want to inform yourself regarding the FAA safety regime, I suggest you read its definitions of failure and the supporting probability metrics. This post

Quoting cornutt (Reply 89):

is also very informative regarding fault trees.

Quoting F9animal (Reply 116):
Stop downplaying it

Nobody's doing that. Some (knowledgeable) posters are providing insight into known facts and design / testing parameters and practices. To suggest an analogy, heart surgeons who perform hundreds of operations do not consider their work particularly dangerous or challenging, because they are aware of and manage the risks. The rest of us are probably terrified, or at least anxious, about undergoing heart surgery. I'd suggest you accord the experienced professionals on this thread, from whom I and many others are learning a lot, the same professional courtesy.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-20 13:10:12 and read 15827 times.

Quoting F9animal (Reply 116):

The plane is grounded because it is not safe.

recognizing that some posts border on trolling, I believe the plane is grounded until the safety of flight is confirmed .. that does not mean it is not safe, it means they want to recheck and validate the safeguards. It's very easy to jump from one to the other, however they are not the same.

Exaggerated statements do not further understanding of the problem nor do they add to the resolution. They do however tie up competent people working on the problem by diverting them away to respond.

Topic: RE: FAA Grounds 787 Part 3
Username: flyingbird
Posted 2013-01-20 13:23:54 and read 15718 times.

Quoting mke717spotter (Reply 119):
Not sure if anyone has mentioned this yet, but is LO's 787 still at ORD or has it been ferried back to WAW yet?

I saw it east of terminal 5, 30 minutes ago.

Topic: RE: FAA Grounds 787 Part 3
Username: dcann40
Posted 2013-01-20 13:28:13 and read 15825 times.

It looks like it may remain there for a while, because the investigation may take weeks or months instead of days based on today's news.

NTSB Rules Out Excessive Voltage as Cause for Dreamliner Battery Fire

Quote:
....The agency did not set a timetable for the investigation, which, according to industry experts, could take months.


[Edited 2013-01-20 13:46:34]

Topic: RE: FAA Grounds 787 Part 3
Username: LTBEWR
Posted 2013-01-20 13:41:26 and read 15706 times.

Some here have suggested that the lithium cell batteries be replaced with ones of other technologies. Problem is that could mean grounding all 787's for a number of months as they and their associated components and software would have to be extensively tested to assure their safety and certification. Due to the possible weight and space issues significant revisions to the a/c structure and wiring to properly fit them may mean further testing, certification and delays.

Perhaps for ferrying with no revenue pax, a temporary battery system of other technology could be put in, and a ferrying permit issued, but for revenue use and delivery of new a/c, they need to be fully fixed or they can't be certified for flight.

Are their any money numbers so far of what the current and potential costs to airlines, Boeing and suppliers of these groundings?

Topic: RE: FAA Grounds 787 Part 3
Username: iahmark
Posted 2013-01-20 13:50:08 and read 15627 times.

I honestly don't think Boeing nor the FAA investigators know what the real culprit is, the longer the planes are grounded the more you get that feeling and also the more negative the image for Boeing..

I believe this will take at least two weeks if not more because the fix -i suspect- won't be that easy to implement, if it were so we would have known it by now!!
Also there many eyes on the story from Asia to Europe with other agendas, for some the longer the 787 stays on the ground the better (PR wise).

Here's something I found (proof that Boeing didn't want to go along with the grounding)
http://seattletimes.com/html/busines...020173453_787teethingpainsxml.html

Topic: RE: FAA Grounds 787 Part 3
Username: KC135R
Posted 2013-01-20 13:50:12 and read 15631 times.

Not sure if anyone can shed any light on this, but I have a question - first, let me explain my thought process.

I was an aircraft maintainer for the better part of 14 years; as a result, I know there are operating limits and then there are max limits - essentially the point at which a component would fail (typically well above the normal operating limit). A crude example - I worked on hydraulic systems which operated at 3,000 PSI, there was a relief valve that would open preventing system pressure from exceeding 3,500 PSI. Even so, most of the components (to include plumbing) in the system were rated to handle much more that that - some all the way up to 8,000 PSI if memory serves. I guess the requirement to load test wings to 150% would follow the same logic.

It seems (if I read the current info correctly) that the JAL battery DID NOT exceed "max" voltage and the ANA battery did. Initially this gave me the impression there are multiple things going on, but applying what I mentioned before gives me a little pause and leads to my question - Was the battery exposed to voltage above its normal operating range, or was the battery exposed to more voltage than it is designed to EVER handle (fail limit)??

These two things are not necessarily the same thing - though I have no inside knowledge of the 787's battery system, I would be incredibly surprised if, for example, going 1V over the normal operating max would lead to a battery failure. If the ANA battery exceeded operating limits but not design limits that still suggests to me that the common thread is the battery. Any insight???

Topic: RE: FAA Grounds 787 Part 3
Username: iahmark
Posted 2013-01-20 14:20:29 and read 15360 times.

Batteries may not have been overcharged but not 100% sure...
http://www.suntimes.com/business/176...advances-faa-tries-to-keep-up.html

Quote:
But NTSB investigators are continuing to look at the battery system. They plan to meet Tuesday with officials from Securaplane Technologies Inc., manufacturer of the charger for the 787s lithium ion batteries, at the company’s headquarters in Tucson, Ariz., said Kelly Nantel, a spokeswoman for the board.

“Potentially there could be some other charging issue,” Nantel said. “We’re not prepared to say there was no charging issue.”

Even though it appears the voltage limit wasn’t exceeded in the case of the battery that caught fire in the Japan Airlines 787 in Boston, it’s possible that the battery failures may be due to a charging problem, according to John Goglia, a former NTSB board member and aviation safety expert.

Too much current flowing too fast into a battery can overwhelm the battery, causing it to short-circuit and overheat even if the battery’s voltage remains within its design limit, he said.

“The battery is like a big sponge,” Goglia said. “You can feed it with an eye dropper or you can feed it with a garden hose. If allowed, it will soak up everything it can from the garden hose until it destroys itself.”

Topic: RE: FAA Grounds 787 Part 3
Username: wjcandee
Posted 2013-01-20 14:32:17 and read 15299 times.

Here's my own feeling...

The FAA is either going to have to find a face-saving way to get the aircraft back in the air based upon some interim standard, or the thing is going to be on the ground for more than six months and maybe a year or more.

The standard they have set out is to "prove" the battery system is safe. This will be a tall order.

To do a true root-cause analysis of this very-complicated system, and design and test a fix or a different system, will take years -- the kind of time an NTSB report takes to be done. And then some.

The current manufacturer *planned* to take *seven years* -- SEVEN -- to design and build the charger. Which it did.

After the battery fire at the charger-manufacturer's plant, it took TWO YEARS to do a root-cause analysis of the cause of the fire.

If the FAA really plan to ground the thing until a root cause analysis is done or a new-from-scratch power system is developed, they will have essentially killed Boeing.

Because of this, I assume that cooler heads will prevail in a week or two, and Boeing and its advocates will start to persuade Congress and other politicians that this was a premature grounding, which it was. Because these people are politicians and not engineers, and thus don't care about the absolute truth, presumably they will be able to find words to spin this to make it appear that the problem is solved, and the thing can get back in the air while they fully-work the issue.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-20 14:35:25 and read 15253 times.

Quoting WingedMigrator (Reply 111):
That much is easy. 32V x 65Ah = 7.5 megajoules

I think the chemical reaction releases a lot more than that.

Topic: RE: FAA Grounds 787 Part 3
Username: JoeCanuck
Posted 2013-01-20 14:41:52 and read 15230 times.

Quoting F9animal (Reply 116):
The plane is grounded because it is not safe.

That's not necessarily true. Those two batteries might be the only anomalies and the rest of the fleet might have flown for decades without problem.

The planes are grounded because they don't know the exact cause(s) of the two battery fires and until they discover that, they have to assume the rest of the identical batteries are potentially unsafe, until proven otherwise or another safe solution is found.

More semantics but there is a significant difference. They do have their work cut out for them. First, they have to find the failure causes, which still might be the same for both batteries, regardless of one overcharging. Then they have to ensure that every battery in every 787 doesn't have the same flaws...which probably takes destructive testing so every battery is likely to be replaced. Then, an all new batch of batteries with the new safeguards will have to be produced, tested, re-certified, tested on the planes and then eventually installed on the planes and they are released for passenger service.

I don't see any of that happening quickly. As an interim step, they take a battery already certified for use in passenger aircraft, (equipment can't tell what type of battery the 32v come from), reprogram the charging software and go directly to flight testing.

My wild arsed guess is that would take at least half the time of waiting for new lithium batteries. Even a few days saved still means millions of dollars saved for everybody.

Quoting nm2582 (Reply 122):
Ok, so an 8 cell pack with 32v as the "never exceed" value: we can assume this pack is simply 8 cells in series; and that Boeing has chosen to set 4V per cell as the maximum (the cells last longer this way than taking them up to the absolute max 4.2V).

The lithium packs that I use on my bikes are 10 cell (in series), 10amp/hr, 36v Lithium Iron Phosphate packs. 36 volts is the middle value between full charge and drain cutoff. At full charge, the batteries are at 42v, controlled by the charger), and they cut off, (controlled by the speed controller, not the battery itself), at 30v.

That range give a relatively steady and flat voltage drop for the 10 amp/hr capacity. Below 30v, the voltage drops off very quickly so in reality, there really isn't much capacity left at 30v.

Every battery works the same way; the rated voltage is essentially, 'nominal' voltage...a mid range between full charge and what they consider 'empty'. Your car battery is 12v but full charge is 14.x, (which is what the system charges at), and will be useful until about 10v. The same principle applies to NiCd, NiMh or any other battery.

I haven't seen the specs of the 787 batteries but 32v is probably the nominal voltage value, rather than the full charge value...which could be 38v or even more. There will also be a safety factor built in since you can't have batteries explode if they go 0.1v over the max charge voltage. I don't know what that safety factor is but there would be a buffer built into the specs.

So an overcharge could be over the rated charged battery voltage and still under the absolute tested safety margin.

A weak cell will manifest itself in a number of ways. You might still get full charge but the capacity is reduced. You test for this with a load tester. This happened on one of my packs and is a common failure mode for auto batteries. A shorted cell will usually only let a pack charge to a lower voltage and is an easy failure mode to detect with a volt meter.

The real beeoch of the whole deal is testing for the cause of the problem is not fun, easy or obvious...and it invariably involves destructing testing.

Topic: RE: FAA Grounds 787 Part 3
Username: rwessel
Posted 2013-01-20 14:47:03 and read 15166 times.

Quoting KC135Hydraulics (Reply 82):
If a pickup-sized Diesel engine requires upwards of 700 cranking amps to turn over, imagine the instanteous draw from the electric starter on the 787's APU. It has to be quite high.

I doubt it. Turbines start up slowly and smoothly, totally unlike a diesel, which require a huge push to deal with the compression. Larger diesels, some paradoxically, are often better, since the so much force would be required to spin it up that they open the valves during the spin up to reduce that problem. You see the same thing done on some small diesel’s that you can hand crank. Some very large gasoline engines that that as well.

And let’s remember, the APU on the 787 is not really all that large. It only drives a pair of 225KVA generators, which assuming only 80% efficiency (way low), implies about 750hp output on the turbine shaft.

Topic: RE: FAA Grounds 787 Part 3
Username: Rheinbote
Posted 2013-01-20 14:48:43 and read 15144 times.

Quoting WingedMigrator (Reply 111):
Quoting cornutt (Reply 106):
I don't know how much energy is involved in these battery failures

That much is easy. 32V x 65Ah = 7.5 megajoules

Not so easy - if parts of the battery are combusted the released energy is much higher, particluarly in case of a metal fire.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-20 14:49:39 and read 15168 times.

Quoting RickNRoll (Reply 133):
I think the chemical reaction releases a lot more than that.

You're probably right. A fully discharged battery isn't charred and burned, so there must be even more chemical potential energy that can be released through combustion.

I have a lithium ion battery on my bicycle that has about 1/5th the energy capacity of this one... Should I worry?  

Topic: RE: FAA Grounds 787 Part 3
Username: Skydrol
Posted 2013-01-20 14:54:37 and read 15078 times.

Quoting KC135R (Reply 130):
I would be incredibly surprised if, for example, going 1V over the normal operating max would lead to a battery failure.

Battery chemistry is such that a one volt difference for a cell in a battery is a huge difference. There isn't a 'design safety factor'.

Consider a common lead-acid car battery... with cells below 2.0 volts, the battery is close to being dead, 2.1 volts charged-idle, 2.4 volts maximum voltage during charge. Anything beyond that and the electrolyte boils out, and the battery will be destroyed. If a dried-out cell shorts, a fire is possible, but the major event is the battery itself is destroyed.

Lithium battery cells are even less tolerant of out of range charging voltages, or overloading due to extreme loads or shorts, and the consequence of either is chain-reaction thermal runaway and one or more, or even all of the cells in the battery explode. The energy release is significant enough to not only destroy the battery, but also cause damage to anything near it.

As has been mentioned by others here several times, the final series voltage of the battery, and measured voltage under charge is not as critical as the voltage drop across each cell in the battery; there is only a fraction of a volt difference between dead, charged and an explosion. The worst scenario is when the individual cell voltages / internal resistances become imbalanced and a common charging current is impressed upon the series-wired cells. The weak cell with highest internal resistance will drop more voltage, not good for lithium cells. Actually, not good for lead-acid batteries either; a cell with low electrolyte level will often go high voltage during charge, and this in turn causes it to boil out even more, compounding the problem and ruining the battery.



✈ LD4 ✈

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-20 15:34:46 and read 14780 times.

Quoting kanban (Reply 125):
I believe the plane is grounded until the safety of flight is confirmed .. that does not mean it is not safe, it means they want to recheck and validate the safeguards.

That's a good way to state it. Currently the aircraft's fault tree has a node labeled "battery failure" which has no number next to it... the number that was there previously has been erased. And at the moment nobody has any idea how to derive the number that belongs there. That means that, at present, the safety of flight is unknown. It could be that the two incidents that have occurred were flukes, and that the aircraft could be released and fly for the next 40 years without another battery failure. Or it could be that it happens again the very next time a 787 is powered up. That's why the 787 is now grounded... it's the inability to quantify the risk. That doesn't mean that the aircraft is unsafe, in the colloquial sense, but it does mean that compliance with that 10^-9 probability standard cannot currently be demonstrated.

Topic: RE: FAA Grounds 787 Part 3
Username: kalvado
Posted 2013-01-20 15:36:50 and read 14751 times.

Quoting Skydrol (Reply 138):
Quoting KC135R (Reply 130):
I would be incredibly surprised if, for example, going 1V over the normal operating max would lead to a battery failure.

Battery chemistry is such that a one volt difference for a cell in a battery is a huge difference. There isn't a 'design safety factor'.

Comparing to original hydraulics example - charge (current) of battery has wider tolerance - like flow or pressure in tubing. Battery voltage is more like tubing diameter - some variation may be OK, but if you came to the point tubing is either collapsing or expanding beyond specs- many bets are off.

Topic: RE: FAA Grounds 787 Part 3
Username: SonomaFlyer
Posted 2013-01-20 15:42:47 and read 14724 times.

Well, this will certainly have a bigger impact on NH then airlines such as UA and the longer it goes of course, the greater the impact given NH is already well along in realigning their fleet and route structure for these a/c.

Its a shame given the benefits this plane provides and the fact this issue will be a difficult one to trouble shoot and likely fix.

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-20 15:58:44 and read 14585 times.

Quoting iahmark (Reply 129):
Also there many eyes on the story from Asia to Europe with other agendas, for some the longer the 787 stays on the ground the better (PR wise).

Frankly I don't see who, so many airlines have the thing on order ! And anything that instill fear of flying in people will have effects on the industry in general.

Quoting wjcandee (Reply 132):
Because of this, I assume that cooler heads will prevail in a week or two, and Boeing and its advocates will start to persuade Congress and other politicians that this was a premature grounding, which it was. Because these people are politicians and not engineers, and thus don't care about the absolute truth, presumably they will be able to find words to spin this to make it appear that the problem is solved, and the thing can get back in the air while they fully-work the issue.

If that happens, I would be far more worried than before. A disaster of epic proportions in the making if another battery burns down (and I'm not talking about the aircraft crashing, I'm talking about the people you mention facing consequences).

Topic: RE: FAA Grounds 787 Part 3
Username: b2319
Posted 2013-01-20 17:03:35 and read 14239 times.

Quoting wjcandee (Reply 132):
Because of this, I assume that cooler heads will prevail in a week or two, and Boeing and its advocates will start to persuade Congress and other politicians that this was a premature grounding, which it was.

Honest, polite question: Can you please substantiate this statement, especially the last eight words of my quote?

Cheers

B-2319

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-20 17:06:03 and read 14208 times.

Quoting cornutt (Reply 139):
That's a good way to state it. Currently the aircraft's fault tree has a node labeled "battery failure" which has no number next to it... the number that was there previously has been erased. And at the moment nobody has any idea how to derive the number that belongs there. That means that, at present, the safety of flight is unknown. It could be that the two incidents that have occurred were flukes, and that the aircraft could be released and fly for the next 40 years without another battery failure. Or it could be that it happens again the very next time a 787 is powered up. That's why the 787 is now grounded... it's the inability to quantify the risk. That doesn't mean that the aircraft is unsafe, in the colloquial sense, but it does mean that compliance with that 10^-9 probability standard cannot currently be demonstrated.

Doesn't it take a long time to get those new numbers?

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-20 17:28:28 and read 14183 times.

Quoting wjcandee (Reply 132):
If the FAA really plan to ground the thing until a root cause analysis is done or a new-from-scratch power system is developed, they will have essentially killed Boeing.

No. Boeing will have killed Boeing.

Quoting wjcandee (Reply 132):
If the FAA really plan to ground the thing until a root cause analysis is done or a new-from-scratch power system is developed, they will have essentially killed Boeing.

If the aircraft flies again and there is another major issue, either with this battery or with another system, the aircraft will be grounded again. And if that happens, it could essentially mean the end of the 787 program. It would be, AFAIK, unprecedented in commercial aviation history.

So they'd better be very sure that they have it right this time around.

Quoting Aesma (Reply 142):
If that happens, I would be far more worried than before. A disaster of epic proportions in the making if another battery burns down (and I'm not talking about the aircraft crashing, I'm talking about the people you mention facing consequences).

And it is a good point. If the aircraft is allowed to be returned to service before the investigators and engineers have a very firm handle of the problem, then the consequences to the FAA regulators will be severe. Careers will be lost. And that's just on the FAA side of the equation. The results for Boeing would be equally disastrous. Nobody would win from such a course of action.

iahmark's article is concerning, but it's also very indicative of the exact attitude I've seen from certain posters on this board who have minimized these issues all along. It's very disconcerting that Boeing is in denial about the word "fire." One would imagine that everyone at Boeing would want to get this fixed finally and perfectly. They simply cannot afford to have the 787 fleet grounded again, and the threshold for the near future will be very low.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-20 18:01:36 and read 13907 times.

Simple question--sorry if it's been answered before. Since the time for the battery to combust itself totally is far less than the certified ETOPS time, is it not a condition for certification that the battery be allowed to combust itself totally, in flight, without endangering life?

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-20 18:03:50 and read 13898 times.

Quoting DocLightning (Reply 145):
then the consequences to the FAA regulators will be severe. Careers will be lost.

Maybe. I cited the Toyota recalls in 2009 and 2010 as a good recent example of a different part of DoT running amok, and the stop sale in early 2010 was the functional equivalent (for cars) of a grounding. AFAIK, no one at NHTSA lost their job over how that was handled.

Quoting DocLightning (Reply 145):
It's very disconcerting that Boeing is in denial about the word "fire."

Come on, Doc. You're a scientist. You know that the media throws around scientific terms of art casually but wrongly all the time. That's exactly what went on with ZA002.

Topic: RE: FAA Grounds 787 Part 3
Username: Skydrol
Posted 2013-01-20 18:44:18 and read 13663 times.

Quoting WingedMigrator (Reply 146):
Simple question--sorry if it's been answered before. Since the time for the battery to combust itself totally is far less than the certified ETOPS time, is it not a condition for certification that the battery be allowed to combust itself totally, in flight, without endangering life?

This may very well be the case, but battery containment was intended to be the last line of defense against an onboard fire and not be relied upon to deal with battery exotherms as a routine event. The first should be to prevent the main and APU batteries from self-destructing using appropriate charging and monitoring methods. The second line of defense should be electrical isolation and disconnection of cells based on unsafe cell voltages or temperatures. And then if all else goes wrong, contain the fire/explosion. I believe we would be crossing a dangerous line if battery melt-downs become an accepted norm. And beyond the inflight fire hazard, a burned-up battery would not be able to perform the required tasks should primary power systems fail; if it really wasn't necessary for the batteries to be charged and serviceable at all times, Boeing surely would have saved the space and weight and deleted them.




✈ LD4 ✈

[Edited 2013-01-20 18:45:53]

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-20 18:44:35 and read 13660 times.

Quoting RickNRoll (Reply 144):
Doesn't it take a long time to get those new numbers?

Maybe. It depends on what the fault mechanism turns out to be. Right now, the biggest problem is that, without knowing what the fault mechanism is, no one knows what to test for. If the fault mechanism can be found, then they can experiment with accelerated-aging testing (on the ground) of some design variations, and get a handle on what fault rates to expect and how to design so as to control it.

The worst situation will be if the failure mechanism can't be identified from the two incidents that have occurred. If that happens, they will have to run a bunch of simulated flight tests on a number of batteries and try to duplicate the failures. That could take months.

Topic: RE: FAA Grounds 787 Part 3
Username: prebennorholm
Posted 2013-01-20 18:46:07 and read 13667 times.

Quoting RickNRoll (Reply 144):
Doesn't it take a long time to get those new numbers?

It will be impossible to predict such a time frame. Therefore the fix will have to be done differently, by rearranging the branches on the fault tree.

That's doable. The really big problem is not that batteries can fail, even if that probability of course shall be minimized. The real issue is that a battery failure can cause collateral damage. The latter is the really touch words from FAA ("could" etc.), and it doesn't need to be the case.

The batteries will be removed from the EE-bays. Their failure mode has proved incompatible with other equipment in there.

Just add turbulence and negative G to the fault tree, and we have the battery goof all over.

The FAA won't accept that. Other CAAs overseeing non-US carriers won't accept that. The airlines won't accept that.

Add to that, this is close to an unparallelled world wide PR disaster. Boeing used the internet and social media to market this plane as the plane of choice ("jet lag free", etc.), and it so far backfired. If they had instead told that they made another plane, bigger than the 737 and smaller than the 777, then... They cannot un-invent the internet. They can only recover by taking a technical action which is clearly explainable to the non-technical public.

It may wipe away the weight advantage over older and proven systems. But just look at the alternative.

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-20 18:52:27 and read 13650 times.

Quoting Cubsrule (Reply 147):
Maybe. I cited the Toyota recalls in 2009 and 2010 as a good recent example of a different part of DoT running amok, and the stop sale in early 2010 was the functional equivalent (for cars) of a grounding. AFAIK, no one at NHTSA lost their job over how that was handled.

I would consider those recalls to be nothing in comparison to this. Cars and airliners are not really analogous other than the fact that they are both transportation.

There was a stop sale. The issue was fixed. Toyota moved on. Toyota was also very responsible and very attentive to getting the recall notices out there and performing the required actions. At no point did I feel like Toyota was trying to minimize the issue. Rather, people were faking accelerator malfunctions and brake malfunctions to try to get money out of Toyota.

And... a plane crash (or the mere suggestion that there's a risk of one) is different from a car crash in the same way that Hurricane Sandy was different from a bit of rain.

This situation is so different, it's not even comparable.

Topic: RE: FAA Grounds 787 Part 3
Username: Aesma
Posted 2013-01-20 18:58:40 and read 13701 times.

And car recalls happen all the time.

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-20 19:09:59 and read 13631 times.

Quoting DocLightning (Reply 151):
There was a stop sale. The issue was fixed. Toyota moved on.

Stop sales are pretty rare (sort of like groundings). Recalls are more like ADs - frequent and not usually newsworthy (for instance, practically no one in the mainstream media is talking about the fact that the new Ford Escape has been recalled four times in a matter of months, including a couple of times for issues that can cause fires). That's why it's an interesting comparison.

In hindsight, the stop sale was absolutely the wrong decision, for there was nothing serious wrong with any Toyota vehicle and absolutely nothing wrong with the vast majority of Toyota vehicles -- those without all-weather floor mats and without the accelerator pedal at issue in the second recall. DoT acknowledges that it was bungled, but there's been no public fallout at the agency. What makes you think that a determination down the road that the 787 grounding was somehow handled incorrectly (either started or ended at the wrong time) would have any different effect?

Topic: RE: FAA Grounds 787 Part 3
Username: sankaps
Posted 2013-01-20 19:14:46 and read 13609 times.

Quoting DocLightning (Reply 151):
I would consider those recalls to be nothing in comparison to this. Cars and airliners are not really analogous other than the fact that they are both transportation.

Fully agree. Besides a stop sale is not the same as a grounding: Toyotas were not taken off the road. It is much more analogous to an AD.

Topic: RE: FAA Grounds 787 Part 3
Username: rotating14
Posted 2013-01-20 19:25:12 and read 13651 times.

http://www.thedenverchannel.com/news...ents-on-boeings-new-787-dreamliner


So I ran across this article that may shed some light on the 787 dilemma. Just as interesting, since the 787 is the first of its kind and there is no other plane to compare it too, how does the FAA properly diagnose the problem(s) so that it won't happen again?

Topic: RE: FAA Grounds 787 Part 3
Username: Skydrol
Posted 2013-01-20 19:39:53 and read 13632 times.

Quoting DocLightning (Reply 151):
There was a stop sale. The issue was fixed. Toyota moved on. Toyota was also very responsible and very attentive to getting the recall notices out there and performing the required actions. At no point did I feel like Toyota was trying to minimize the issue. Rather, people were faking accelerator malfunctions and brake malfunctions to try to get money out of Toyota.

Sorry to go off the 787 topic, but wasn't the root cause found to be the driver side floor mat could bunch up and jam the bottom of the accelerator pedal? And gosh, no driver on earth would realize the safe way to stop the acceleration of a 'runaway car' is accomplished by turning the ignition key OFF. Now, if turning the ignition off or selecting neutral on the transmission didn't stop the car from accelerating, Toyota would be responsible for an unsafe design. But as it was, Toyota went over and above what was necessary. As to the 'fakes' Doc mentioned, I remember one Prius driver who was on the news stating his car accelerated wildly out of control to 120 MPH. A Prius accelerating wildly out of control to 120 MPH? Give me a break! In the forty or fifty second yawn-fest that ensued getting up to that speed (if a Prius is actually able to go that fast), it never occured to the driver to select neutral or kill the ignition? Hopefully they crawled back under their stone.


Back to the 787... I must admit I am a life-long Boeing fan, and I am very concerned about the 787 devastating their reputation, from an airline standpoint and from a passenger standpoint. With all the negative publicity, will anyone ever really trust the outcome of the investigation, even if they announce they have found the fault?

The 787 jabs are already going around:

''ScreamLiner'', ''Boeing Broiler'', ''Come Fry with us'', ''Arrive alive in aluminum, or perish in plastic''

Quoting DocLightning (Reply 145):
If the aircraft flies again and there is another major issue, either with this battery or with another system, the aircraft will be grounded again. And if that happens, it could essentially mean the end of the 787 program. It would be, AFAIK, unprecedented in commercial aviation history.

So they'd better be very sure that they have it right this time around.

I really feel bad for the employees who worked so hard on this project, only to have it become a PR nightmare. Air Canada was planning to add the B-787 to their fleet next year, now I wonder if they still want to?




✈ LD4 ✈

[Edited 2013-01-20 19:54:36]

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-20 19:43:36 and read 13626 times.

Quoting sankaps (Reply 154):
Fully agree. Besides a stop sale is not the same as a grounding: Toyotas were not taken off the road. It is much more analogous to an AD.

The analogy is important (but imperfect) because of how rare both events are. The fact that NHTSA deals with recalls on a daily basis doesn't really prepare them to handle a stop sale.

Similarly, the fact that FAA handles ADs on a daily basis doesn't prepare them to ground a type. I am confident that in hindsight, we will all find much to criticize in how FAA handled this grounding, but that's the nature of the beast.

Topic: RE: FAA Grounds 787 Part 3
Username: Newark727
Posted 2013-01-20 19:52:25 and read 13541 times.

Quoting Skydrol (Reply 156):
Air Canada was planning to add the B-787 to their fleet next year, now I wonder if they still want to?

Seems as if a year ahead will give them time enough to plan around this, by then something will have been found to get the type back in the air and that's the important part in the long run even if passenger perception does suffer a bit. I figure the carriers that were getting them, adding more, or starting destinations in the next few weeks/months would have more to worry about.

Topic: RE: FAA Grounds 787 Part 3
Username: AeroWesty
Posted 2013-01-20 20:26:36 and read 13366 times.

Quoting rotating14 (Reply 155):

http://www.thedenverchannel.com/news...liner

The end of this article is pretty damning against the FAA:

"In other words: the investigation is becoming a lot more complex than expected, which will likely delay the Dreamliner's return to the air.

But there's a bigger picture here: The complexity of this problem is also raising questions about whether the F-A-A is equipped to oversee such sophisticated technology.

The FAA failed to detect these problems in its original inspection process."


There were 'special conditions' in the certification process which the 787 had to adhere to. What possible problems in the design did the FAA fail to detect?

Topic: RE: FAA Grounds 787 Part 3
Username: KELPkid
Posted 2013-01-20 20:43:43 and read 13230 times.

Quoting AeroWesty (Reply 159):
There were 'special conditions' in the certification process which the 787 had to adhere to. What possible problems in the design did the FAA fail to detect?

No doubt that when they find it, 14 CFR Part 25 (transport category certification rules) will be a few paragraphs longer  

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-20 20:54:30 and read 13149 times.

Quoting AeroWesty (Reply 159):
The end of this article is pretty damning against the FAA:

"In other words: the investigation is becoming a lot more complex than expected, which will likely delay the Dreamliner's return to the air.

But there's a bigger picture here: The complexity of this problem is also raising questions about whether the F-A-A is equipped to oversee such sophisticated technology.

The FAA failed to detect these problems in its original inspection process."

The FAA may be a little behind the times in their knowledge, and lithium cells are pretty new in airliners. I don't think the problem is too complex for them to come to understand, but perhaps they don't understand it as well (yet) as they need to. Certainly a lot of people at NTSB and FAA are getting crash-courses in lithium technology over the past weeks, and you can bet that additional policies, procedures, regulations, etc. will result with a net increase in safety for all.

In some ways, it seems a little similar to me as the square window problem in the Comet. Metal fatigue wasn't particularly well understood at the time, but they did their best with testing, went above and beyond the norm of the day; but the end result was that there were still unknowns that lead to some catastrophic failures. I think it is unlikely that the 787 will take the same path as the Comet; but there are similarities in the learning curve. Further, I do expect all the hulls currently built to be back in the air - but there will be modifications, no doubt.

Topic: RE: FAA Grounds 787 Part 3
Username: AeroWesty
Posted 2013-01-20 21:01:47 and read 13103 times.

Quoting KELPkid (Reply 160):
No doubt that when they find it

The investigation has barely begun. If I'm reading things right, it's still possible that the design is solid, but the execution of it was faulty. Or is that completely off the mark?

Topic: RE: FAA Grounds 787 Part 3
Username: tdscanuck
Posted 2013-01-20 21:20:36 and read 13044 times.

Have been travelling, very late to the party. Picking up some stuff from the prior threads:

"Am still hoping Tdscanuck or CM will comment in whether or not atmospheric pressure changes might have a role.. (See post 1)"

Possible, but heavily tested so unlikely.

Quoting art (Reply 7):
Could any of the cognoscenti hazard how long the grounding will be if it is determined that the problem is "simply" manufacturing defects in the batteries concerned?

Best case is they discover a manufacturing defect that's detectable...then they just have to inspect the fleet batteries for the defect and clear those that don't have the defect. An approximately similar thing happened with 737NG fuel pumps several years ago (they had to be X-rayed to make sure some internal wires were in the right place). That could be done on the order of days/a few weeks.

Quoting Aesma (Reply 15):
The basis for certification is that many kinds of failures can happen, without downing the aircraft. If we now discover failures that were not predicted, all bets are off.

cornutt summed this up far better than I could. Failures that weren't predicted are very bad, but this isn't a failure that wasn't predicted. It's just that the failure probability might be way off...this is also bad, but considerably more tractable than unanticipated failure modes.

Quoting PW100 (Reply 16):
Can't we all just agree that in the view of the regulators (FAA, EASA etc), anything supposed to be airborne that has not been demonstrated to be safe, is by definition unsafe?

No. That's not how the regulations work. Under that system, nothing would ever get certified.

Quoting francoflier (Reply 27):
in flight fire is never, ever something where you can say there is no risk of losing the aircraft. Especially when it happens in an inaccessible area with little fire protection/fighting capability.

Although it's true that you can never say there is *no* risk of losing the aircraft, you can estimate how likely it is for a fire to result in loss of the aircraft. In this case, since a battery fire was a design condition, the probability of a catastrophic event is still very very low. That doesn't make fires acceptable, in any way, but it does moderate the gap between likelyhood of a battery fire and likelyhood of a hull loss.

Quoting RickNRoll (Reply 55):
Not wanting to be a pain, but it only fixes the problem of the batteries failing as they have recently. They still need to address the issue of containing a battery adequately when it does fail.

So far, the existing events have demonstrated that the containment *does* work.

Quoting JoeCanuck (Reply 60):
My opinion is that these Li-ion batteries, (and batteries of similar chemistry), are unsuitable for high power applications on aircraft. The probability of failure and the difficulty in predicting failures, as well as the violent way they fail, raise them above the level of acceptable risk.

That's not necessarily true; you could assume the probability of a battery fire is 1, then modify the containment to still keep the probability of a catastrophic event to be extremely remote. This is, obviously, not what will actually happen but risk gets assessed at the aircraft level, not the component level, so component reliability doesn't directly inform what acceptable risk is.

Quoting bonusonus (Reply 69):
How and when does each type of battery get charged? And how much recharging is typically required in each?

Both batteries are charged anytime the airplane system is energized by another source (ground power, engine generators, or APU) until they're full, then they're just periodically checked. Since Li-ion doesn't discharge quickly when not used, they'll basically just sit there until they experience a current draw again. Since 787's like to stay powered up, any carrier that keeps them on ground power may never be charging the battery in any significant way.

Quoting KC135Hydraulics (Reply 82):
If a pickup-sized Diesel engine requires upwards of 700 cranking amps to turn over, imagine the instanteous draw from the electric starter on the 787's APU. It has to be quite high.

Not so bad...700Ax12V = 8400W. The 787 APU doesn't have a load compressor so it's only operating at very low power when starting and the battery is at higher voltage...I suspect it's actually pulling a lot less than 700A.

Quoting sweair (Reply 90):
So to repeat my question, would or could a fuel cell fueled by Jet-A be safer than a battery?

Could? Yes. Would? Unlikely.

Quoting sweair (Reply 90):
They create heat, but has there been any serious incidents with fuel cells?

I think fuel cells have melted down, but the problem is usually around the fuel or reformer rather than the cell itself.

Quoting packsonflight (Reply 92):
The 787 did not contain the battery failure properly. As far as I can see this is a fact, and Boeing definitely have to make some hardware changes here and get them certified.

How is this a fact? In both cases, the battery fire was contained and no other equipment was taken down in the process. Isn't that the containment requirement?

Quoting teme82 (Reply 113):
Quoting WingedMigrator (Reply 111):
That much is easy. 32V x 65Ah = 7.5 megajoules

I think that is more than enough to cause serious issues with the aircraft. If all the batteries would fail at the same time it would be really bad day for that plane and it's occupants.

The batteries aren't co-located and both battery areas are designed to contain the full energy of a battery fire indefinitely. It would be very very bad from a reliability standpoint but, at least based on the current facts, wouldn't present a danger of loss of the aircraft.

Quoting F9animal (Reply 116):
The plane is grounded because it is not safe.

No. The plane is grounded because the regulators don't feel that Boeing has adequately proven that it meets the requirements. It is absolutely true that the regulators will ground a plane that is unsafe but that's not the only reason.

Quoting F9animal (Reply 116):
A fire from a battery is dangerous. Stop downplaying it, because it is what it is.

I agree it shouldn't be downplayed, but it also shouldn't be up-played. Fire is dangerous. Fire in an area designed to contain a fire, however, is a heck of a lot less dangerous than fire in an area not designed for it. This is *the* major difference between these events and Swissair111.

Quoting RickNRoll (Reply 144):
Doesn't it take a long time to get those new numbers?

You can always put them up to 1 and see how that impacts the rest of the fault tree; this is conservative and gives you an idea of what the allowable range of numbers is.

Quoting WingedMigrator (Reply 146):
Since the time for the battery to combust itself totally is far less than the certified ETOPS time, is it not a condition for certification that the battery be allowed to combust itself totally, in flight, without endangering life?

Yes.

Quoting prebennorholm (Reply 150):
The batteries will be removed from the EE-bays. Their failure mode has proved incompatible with other equipment in there.

How so? What other equipment stopped functioning?

Quoting Skydrol (Reply 156):
With all the negative publicity, will anyone ever really trust the outcome of the investigation, even if they announce they have found the fault?

Well, at least one person will. I suspect I know others.

Tom.

Topic: RE: FAA Grounds 787 Part 3
Username: wjcandee
Posted 2013-01-20 21:24:06 and read 12997 times.

It does appear that everyone, the FAA included, has lost some perspective here.

The biggest concern of the pundits (and by extension, the public) at the outset was the extensive use of CFRP in the hull and wings.

Remember how everyone freaked when they saw those wings bend up on takeoff? Surely that can't be safe, right?

Turns out that on this whole ship, in its production version, the thing that has grounded it (other than politics) is a freakin' battery. Something that, at the end of the day, is barely-necessary. And something that they spent seven years designing and testing. And something that still, as far as I can tell, even with a complete failure of the battery [i.e. ignition] never posed a safety of flight issue and never spread beyond the containment. To my mind, this occurrance is many orders of magnitude more safe than a contained single-engine failure (i.e. blade off) at climb thrust, which is an event that gets no notice in the mainstream press when it occurs.

Since there is no effective extinguishing agent other than burying it, how about they just attach the thing to a parachute, mount it on a hatch, and if it catches fire...poof! Overboard it goes.   Frankly, just as sensible as evacuating an aircraft on the runway when there is no indication of fire or actual smoke, as ANA did. Hysteria much?

All aircraft have batteries. All batteries have the possibility of thermal runaway. Didn't someone say that they're next to the loo on the KC135? Plainly, this is a problem that can be solved in the long run. The only thing that is sad to me is that, without any demonstrated effect on safety of flight, the plane has been grounded while the problem is being solved.

[Edited 2013-01-20 21:35:08]

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-20 21:31:23 and read 12991 times.

Quoting Cubsrule (Reply 157):
Similarly, the fact that FAA handles ADs on a daily basis doesn't prepare them to ground a type. I am confident that in hindsight, we will all find much to criticize in how FAA handled this grounding, but that's the nature of the beast.

Two aircraft in a 72-hour period had an onboard FIRE (no, I am not backing down from that word). It might have been contained. It might have been slow. But it was combustion where there should be none. Both fires were in the same component and there were only about 50 frames in service on this brand-new type. Darned right it should be grounded. The only "mishandling," if any, was that it took the FAA until the next day to ground it.

Quoting AeroWesty (Reply 159):
But there's a bigger picture here: The complexity of this problem is also raising questions about whether the F-A-A is equipped to oversee such sophisticated technology.

Fair enough point. But then again, the FAA does not design the aircraft or make it safe. The OEM (Boeing, in this case) does that. The FAA is not at fault for the primary failure. I will point out that the OEM also failed to detect these problems during testing. The FAA is only in charge of enforcement.

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-20 21:32:21 and read 12904 times.

Quoting AeroWesty (Reply 162):
If I'm reading things right, it's still possible that the design is solid, but the execution of it was faulty. Or is that completely off the mark?

there is no yes or no to your question... just a maybe/maybe not...
The problem with wanting to state absolutes now before the final answer is avai is people with other answers rather than accept, will argue conspiracy and coverup.. or political intention.

one of the advantages of being old, is we recognize that there is more we don't know than what we do know.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-20 21:38:13 and read 12905 times.

Quoting kanban (Reply 110):
The NTSB reported on Jan 20th 2013 that a first examination of the flight data recorder of JA829J showed the nominal battery voltage of 32V has never been exceeded. The battery, powering the APU for APU startup, has been disassembled into its 8 cells for detailed examination and documentation, 3 of the cells were selected for further disassembly and examination of cell internal components.

Thanks, so we now know that a single cell died and did run away thermally. I also have to say that 8 cells is not much for such a high capacity. Why the selection of high currents instead of higher voltages?

We also must assume now, that the charger seems to have failed (we do assume, that it has a balancer).

It is the chargers responsibility, to deal with each single cells and prevent it from becoming hot.

Quoting KC135R (Reply 130):
It seems (if I read the current info correctly) that the JAL battery DID NOT exceed "max" voltage and the ANA battery did.

Max voltage is meaningless as explained by me and much more in detail by nm2582.

Quoting iahmark (Reply 131):
Even though it appears the voltage limit wasn’t exceeded in the case of the battery that caught fire in the Japan Airlines 787 in Boston

Dito.

Quoting JoeCanuck (Reply 134):
I haven't seen the specs of the 787 batteries but 32v is probably the nominal voltage value, rather than the full charge value...which could be 38v or even more.

Usually cellNumber x 3.7V is considered as nominal. 4.2V is the ultimate max voltage (for lipo, there are other types of lithium batteries with slighty different voltages). Above that (and it is a very tight tolerance), the cell swolls and starts overheating. So 38V can never be reached without fireworks with 8 lipo cells.

So what we know is:
- The regulatory requirements demanded, that no cell would ever heat up to unsafe temperatures -> that requirement was broken. So there must be flaw. There is a gap how the system performed, and how it should have performed.

- The technical solution to prevent that, would first be a balancer and second a cell temperature monitoring. I do assume, that both capabilities are build into that charger (anything else would be culpable and fully warrant the grounding).

- But one of these two solutions failed. Possible reasons:

- Wrong wiring in the balancer.

- Defective electronics. But we read, that these systems exist redundantly. But still, there are single points of failures e.g. in the area of the amplifier, that generates the charging current per cell.

- Undetected criteria. E.g. low cell temperatures, as they could happen often inflight, change the characteristics quite a bit. Are all the effects on the battery coming from environmental influences modelled correctly in the charging system?

Topic: RE: FAA Grounds 787 Part 3
Username: AeroWesty
Posted 2013-01-20 21:45:11 and read 12846 times.

Quoting DocLightning (Reply 165):
Fair enough point. But then again, the FAA does not design the aircraft or make it safe.

What you quoted from my post was what I was quoting from the article (the reason why it was enclosed in quote marks and set in italics).

Quoting DocLightning (Reply 165):
I will point out that the OEM also failed to detect these problems during testing.

Which problems? In the design or execution of the design?

Quoting kanban (Reply 166):
there is no yes or no to your question... just a maybe/maybe not

That's what I was thinking. We just don't know enough yet to be damning towards any part of the process, expressed well by tdscanuck in his recent post quoted below. We don't know what failure it is yet that needs correcting.

Quoting tdscanuck (Reply 163):
The plane is grounded because the regulators don't feel that Boeing has adequately proven that it meets the requirements.

Topic: RE: FAA Grounds 787 Part 3
Username: BestWestern
Posted 2013-01-20 21:52:07 and read 12784 times.

Quoting wjcandee (Reply 164):
The only thing that is sad to me is that, without any demonstrated effect on safety of flight, the plane has been grounded while the problem is being solved.

We have to have confidence in the FAA. If they deem the aircraft potentially unsafe to fly, we have to accept their opinion, and stop second guessing them.

When they deem the aircraft safe to fly, we have to accept their opinion and not second guess them as they know far more than we will ever do.

Quoting wjcandee (Reply 164):
the thing that has grounded it (other than politics) is a freakin' battery.

Politics didn't ground this aircraft - if anything there is political pressure in the other direction, as Boeing is part of the fabric of the US economy.

Quoting Skydrol (Reply 156):
With all the negative publicity, will anyone ever really trust the outcome of the investigation, even if they announce they have found the fault?

Me, I have total confidence that the 787 will continue to be a safe, competitive, value for money aircraft. If it takes one more month to ensure that, so be it. It will be forgotten about in twelve months when the media circus is onto something else.

Quoting Skydrol (Reply 156):
''ScreamLiner'', ''Boeing Broiler'', ''Come Fry with us'', ''Arrive alive in aluminum, or perish in plastic''

Sticks and stones may break my bones.....

We are lucky then the aircraft are bought by bean counters who read the New York Times, China Daily or the Economist, rather than some sensationalist rag of a 'newspaper'

Topic: RE: FAA Grounds 787 Part 3
Username: airtechy
Posted 2013-01-20 21:53:31 and read 12828 times.

Having been involved in a lot of engineering to try to determine a design failure mode....but never with a battery...I'm guessing that a sharp engineer will postulate a cause for the failure, they will start with a new battery with this deliberately created fault, and they will test it to failure maybe accelerating the test conditions. They can't take a year to test for failure.

I doubt they will learn anything from the two charred batteries.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-20 22:00:25 and read 12834 times.

Quoting DocLightning (Reply 145):
It's very disconcerting that Boeing is in denial about the word "fire."
Quoting DocLightning (Reply 165):
Two aircraft in a 72-hour period had an onboard FIRE (no, I am not backing down from that word).

Doc, I get it that you do not like what Boeing has said (or has not said) in their public communications about the two battery fires. What you may not realize is that once the NTSB opens an investigation into any accident or incident, all public comments on the subject from the OEM are dictated by the NTSB. Boeing cannot legally comment on the battery issue beyond a set of statements which are entirely controlled by the NTSB.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-20 22:10:15 and read 12733 times.

Quoting CM (Reply 171):
Boeing cannot legally comment on the battery issue beyond a set of statements which are entirely controlled by the NTSB.

I cannot believe that even for a second. They might be strongly discouraged from commenting, and even further discouraged by the possibility of inadvertent self-incrimination, but legally barred? No such law on the books.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-20 22:26:02 and read 12645 times.

Quoting WingedMigrator (Reply 172):

Every time the NTSB opens an investigation, the instructions to Boeing are made crystal clear by the NTSB; there can be no public communication on the subject without the NTSB having the final right or review, edit or reject the communication, with the NTSB typically providing direct guidance on what to say and when to say it. I don't know if it is a matter of legislation or not, but for all practical purposes it may as well be. Any time there is an active NTSB investigation, they are dictating what the OEM can and cannot say about the matter.

Topic: RE: FAA Grounds 787 Part 3
Username: tdscanuck
Posted 2013-01-20 22:28:39 and read 12634 times.

Quoting AeroWesty (Reply 162):
If I'm reading things right, it's still possible that the design is solid, but the execution of it was faulty. Or is that completely off the mark?

Yes, that's a possibility.

Quoting wjcandee (Reply 164):
Since there is no effective extinguishing agent other than burying it, how about they just attach the thing to a parachute, mount it on a hatch, and if it catches fire...poof! Overboard it goes.   Frankly, just as sensible as evacuating an aircraft on the runway when there is no indication of fire or actual smoke, as ANA did. Hysteria much?

I disagree...ANA did the right thing. They'd just had a battery fire. Then, very soon after, they got a battery warning and a funny smell...evacuation was the prudent thing to do. Evacuation, although quite likely to cause minor injuries, is very unlikely to hurt anybody in a major way. There is almost no harm (and considerable potential benefit) to evacuating when you're not sure what's going on.

Quoting wjcandee (Reply 164):
All aircraft have batteries. All batteries have the possibility of thermal runaway.

True. That's why the possibility was designed in. However, the FAA required a certain maximum probability of a fire. With a single data point (the Boston event) you get no data on probability so the FAA had nothing to go on. With the second event, you get frequency data, and it pointed in a direction that was certainly against what the FAA had requested. Hence the situation changed drastically after the second event.

Quoting wjcandee (Reply 164):
The only thing that is sad to me is that, without any demonstrated effect on safety of flight, the plane has been grounded while the problem is being solved.

It's not about demonstrated effect on safety of flight, it's about demonstration of compliance with regulations. There are lots of ridiculous regulations that you still have to comply with, even if they have no direct bearing on safety of flight.

Quoting DocLightning (Reply 165):
The only "mishandling," if any, was that it took the FAA until the next day to ground it.

I disagree. After the first event, nobody had any data on whether this was very bad luck or the start of something...you don't get any rate data off a single event. All that the first event did was show that something that was believed to be possible was possible. The second event provided rate date...that's what triggered the FAA, I suspect.

Quoting DocLightning (Reply 165):
I will point out that the OEM also failed to detect these problems during testing.

That's only relevant if it's a design problem, and so far we don't know what it is. OEM testing can only pick up a manufacturing defect during testing if the defect is also present during the testing.

Quoting airtechy (Reply 170):
I doubt they will learn anything from the two charred batteries.

You'd be surprised at how good aviation investigators are. They can learn incredible things from what appear to be useless lumps of charred rubble.

Tom.

Topic: RE: FAA Grounds 787 Part 3
Username: wjcandee
Posted 2013-01-20 22:33:52 and read 12523 times.

Quoting WingedMigrator (Reply 172):
Quoting CM (Reply 171):
Boeing cannot legally comment on the battery issue beyond a set of statements which are entirely controlled by the NTSB.

I cannot believe that even for a second. They might be strongly discouraged from commenting, and even further discouraged by the possibility of inadvertent self-incrimination, but legally barred? No such law on the books.

Well...time for the lawyer to do what lawyers do:

49 CFR 831.13

"§ 831.13
Flow and dissemination of accident or incident information.
(a) Release of information during the field investigation, particularly at the accident scene, shall be limited to factual developments, and shall be made only through the Board Member present at the accident scene, the representative of the Board's Office of Public Affairs, or the investigator-in-charge.
(b) All information concerning the accident or incident obtained by any person or organization participating in the investigation shall be passed to the IIC through appropriate channels before being provided to any individual outside the investigation. Parties to the investigation may relay to their respective organizations information necessary for purposes of prevention or remedial action. However, no information concerning the accident or incident may be released to any person not a party representative to the investigation (including non-party representative employees of the party organization) before initial release by the Safety Board without prior consultation and approval of the IIC."

There's other stuff out there along these lines. The point is that the NTSB is in control of the information flow.

That's why Boeing is gritting its teeth, and folks like Gordon Bethune are being rolled out to call the FAA morons for the grounding.

[Edited 2013-01-20 22:36:10]

Topic: RE: FAA Grounds 787 Part 3
Username: BoeingVista
Posted 2013-01-20 22:43:20 and read 12460 times.

Quoting CM (Reply 173):

But the FAA won't put words into Boeings mouth, i.e if Boeing don't say fire the FAA wont insert the word fire into Boeing communication so Doc's point still stands, De Nile is a river that runs through Chicago.

Quoting tdscanuck (Reply 174):

Seems like a reasonable summation

A couple of Questions for the Boeing guys:

Do the individual cells on the 787 battery have individual charging circuits?

What if any systems or capabilities does the 787 lose if it loses the main battery?

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-20 22:49:11 and read 12672 times.

Quoting wjcandee (Reply 175):

Thanks for that. Also found additional (similar) rules for parties to an investigation here: http://www.ntsb.gov/doclib/forms/NTSB_Investigation_Party_Form.pdf which is effectively the contract the OEM signs when they are made a party to the investigation.

It appears it is a matter of legislation, as the document cites 49 C.F.R. §§ 831.11 and 831.13 as the authority for the policy.

Quoting BoeingVista (Reply 176):
But the FAA won't put words into Boeings mouth, i.e if Boeing don't say fire the FAA wont insert the word fire into Boeing communication so Doc's point still stands, De Nile is a river that runs through Chicago.

It's the NTSB, and I suggest you go read the linked policy. It makes it clear the words which are made public or provided to the media - all of them - will come from the NTSB.

Topic: RE: FAA Grounds 787 Part 3
Username: WingedMigrator
Posted 2013-01-20 22:55:49 and read 12599 times.

Quoting tdscanuck (Reply 174):
you don't get any rate data off a single event.

Sure you do: you've had one event per N flight hours. You have a rate from that, albeit with a wide confidence interval. Two observations will give you a tighter confidence interval, three even more, etc.

Quoting wjcandee (Reply 175):
49 CFR 831.13

Thanks    and apologies to CM.

Topic: RE: FAA Grounds 787 Part 3
Username: CO953
Posted 2013-01-20 23:02:14 and read 12490 times.

So I am wondering what sort of activity, if any, there is in the desert to put mothballed frames back in the air, to make up for lost 787 capacity? What sort of capacity pinch are the Japanese, especially, facing?

Also, does anyone remember what sort of capacity pinch happened when the DC-10 was grounded? Did airlines pull planes out of the desert?

Or did/will everyone just tough it out for the time being and lose customers if not enough seats are available?

Thanks

Topic: RE: FAA Grounds 787 Part 3
Username: rwessel
Posted 2013-01-20 23:03:54 and read 12480 times.

Quoting WingedMigrator (Reply 172):
I cannot believe that even for a second. They might be strongly discouraged from commenting, and even further discouraged by the possibility of inadvertent self-incrimination, but legally barred? No such law on the books.

The actual rule is probably in the agreement that the non-NTSB parties have with the NTSB, but check out slide 12 of:

http://www.ncdot.gov/transcomm2012/about/IncidentManagmentNTSB.pdf

Probably a party would not face a criminal sanction violating the rule, just the contractual one, but will likely get bounced out of the investigation if they do. And just how long is the NTSB's investigation of the 787 going to take *without* Boeing's expertise?

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-20 23:11:41 and read 12451 times.

Anybody who callas the FAA morons for that grounding is a moron. An in-flight fire which can not be put down by any means available on the plane is a huge risk. The battery failing is not a huge problem, the failure mode is. Just read up how long the fire department in Boston needed to kill the fire and how hard it is to kill such a battery fire, this is a big problem for an ETOPS180 or ETOPS 120 plane. The battery should not ignite and it should not spill its contents, which means that the containment also failed.

For me the FAA faces 3 facts.

1. those batteries fail (that is the easy one)
2. the failure mode is critical (by design), the designed counter measure fails as well (containment)
3. there is no other option available on the plane to put out a battery fire

Topic: RE: FAA Grounds 787 Part 3
Username: AeroWesty
Posted 2013-01-20 23:11:55 and read 12465 times.

Quoting CO953 (Reply 179):
Also, does anyone remember what sort of capacity pinch happened when the DC-10 was grounded? Did airlines pull planes out of the desert?

United was still a dozen or so years from retiring their stretch DC-8s, which they could substitute on some of the DC-10 routes. One flew the morning outbound/evening return for SFO-IAD-SFO at the time as a sub.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-20 23:18:56 and read 12488 times.

Quoting WingedMigrator (Reply 178):
Thanks and apologies to CM.

Thanks, but not at all necessary. I've learned from more of your posts over the years than I can count. We're all a bit smarter because of others here.

Topic: RE: FAA Grounds 787 Part 3
Username: packsonflight
Posted 2013-01-20 23:50:12 and read 12290 times.

Quoting tdscanuck (Reply 163):
How is this a fact? In both cases, the battery fire was contained and no other equipment was taken down in the process. Isn't that the containment requirement?

From the FAA original statement:

"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"

I see no argument here!

Topic: RE: FAA Grounds 787 Part 3
Username: wjcandee
Posted 2013-01-21 00:03:11 and read 12195 times.

When you sign the form that CN linked to, you agree to abide the rules in the attached Guidance for Parties, which can be found at: http://www.nata.aero/data/files/ntsb_investigation_party_form.pdf The Guidance is annexed directly behind the form to be signed.

The relevant portion is as follows:

"VIII.
Release of Information
Prior to the NTSB’s adoption of the final report, only appropriate NTSB personnel are authorized to publicly disclose investigative findings, and, even then, the release shall be limited to verified factual information identified during the course of the investigation. In addition, party participants or their respective organizations must refrain from providing opinions or analysis of the accident outside of the participants in the investigation. Failure to abide by these requirements may lead to removal of a party from the investigation."

Also: from Section VII: "Limitations on parties commenting publicly on possible findings of the investigation, including the probable cause of the accident, will remain in effect until after the Board adopts the final report."

So its pretty clear that you let NTSB do the talking until the final report, in terms of characterizations and expected outcomes, or you can lose your party status.

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 01:00:39 and read 11901 times.

http://www.ainonline.com/aviation-ne...battery-fires-keeping-li-ion-caged

One solution could be putting the batteries in similar bags and adding a Halon injection system that fills the bag in case of a runaway cell. It would probably also be an option to reduce the number of cells in each battery pack.

Topic: RE: FAA Grounds 787 Part 3
Username: BoeingVista
Posted 2013-01-21 01:17:55 and read 11795 times.

Quoting CM (Reply 177):

It's the NTSB, and I suggest you go read the linked policy. It makes it clear the words which are made public or provided to the media - all of them - will come from the NTSB.

You know, no.

The linked document says the NTSB will be the only voice but Doc and myself were referring to the Boeing statement on the Boston incident http://boeing.mediaroom.com/index.php?s=43&item=2554 that failed to mention a fire and was clearly made by BOEING not the NTSB after the NTSB had begun the investigation... So I'm really not getting your point here at all...

Topic: RE: FAA Grounds 787 Part 3
Username: flood
Posted 2013-01-21 01:21:02 and read 11774 times.

Quoting CM (Reply 171):
Doc, I get it that you do not like what Boeing has said (or has not said) in their public communications about the two battery fires. What you may not realize is that once the NTSB opens an investigation into any accident or incident, all public comments on the subject from the OEM are dictated by the NTSB. Boeing cannot legally comment on the battery issue beyond a set of statements which are entirely controlled by the NTSB.

So while the NTSB repeatedly used the term "fire" in their January 8th press release, Boeing was then told by the NTSB to call it a "787 event". Sorry, that's downright comical.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-21 01:30:57 and read 11680 times.

Quoting tdscanuck (Reply 163):
So far, the existing events have demonstrated that the containment *does* work.

I guess this is why I seem to be repeating myself. According to the FAA, containment did not work. They say exactly why they think it didn't work. Smoke and flammable material were not contained, and posed a potential hazard to other aircraft systems. You could say that nothing was damaged by the "containment" that is being disputed, but the FAA feels it is not satisfactory in that it could have damaged important systems.

Topic: RE: FAA Grounds 787 Part 3
Username: KC135Hydraulics
Posted 2013-01-21 01:40:38 and read 11605 times.

But the material did not cause damage to any other major system. How was that a failure of the containment?

Topic: RE: FAA Grounds 787 Part 3
Username: FlyingAY
Posted 2013-01-21 02:03:33 and read 11488 times.

Quoting KC135Hydraulics (Reply 190):
But the material did not cause damage to any other major system. How was that a failure of the containment?

Because FAA believes that there is a chance that we won't get that lucky the next time. The words from FAA: "These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment".

Topic: RE: FAA Grounds 787 Part 3
Username: abba
Posted 2013-01-21 02:14:47 and read 11387 times.

Quoting KC135Hydraulics (Reply 190):
But the material did not cause damage to any other major system. How was that a failure of the containment?


I find your argument basically flawed. The fact that the material didn't actually cause damage to any other system doesn't mean that the containment didn't fail. The very fact that the material left the container means that it wasn't contained. Whether or not it did any damage - once not contained as it should have been - is an entirely different matter.

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-21 02:22:49 and read 11339 times.

Quoting seahawk (Reply 181):
An in-flight fire which can not be put down by any means available on the plane is a huge risk

But no such thing ever happened here

Quoting seahawk (Reply 181):
Just read up how long the fire department in Boston needed to kill the fire and how hard it is to kill such a battery fire, this is a big problem for an ETOPS180 or ETOPS 120 plane.

For the actual fire-fighting on the ground, I suggest you read the posts by rcair1
But fire-fighting on the ground and containement in flight are 2 different problems, as has already been mentioned countless times on these threads. Sure, they are related, but you can't directly apply knowledge regarding one scenario to the other

Quoting seahawk (Reply 181):
The battery should not ignite and it should not spill its contents, which means that the containment also failed

Not necessarily, if the contents spilled in a way which does not endanger critical systems then it worked. Which seems to be the case in these 2 incidents. However it seems that preliminary observations indicate that under additonnal specific circumstances, there is a possibility of critical damage. Such possibilities have to be rigorously ruled out before the planes can fly again.
But this does not mean that the system actually failed in Boston or in Japan

Quoting packsonflight (Reply 184):

I see no argument here!

see above

Quoting FlyingAY (Reply 191):

Because FAA believes that there is a chance that we won't get that lucky the next time.

Exactly ! But that does not mean the containement failed in the 2 actual incidents

Quoting BoeingVista (Reply 187):
but Doc and myself were referring to the Boeing statement on the Boston incident http://boeing.mediaroom.com/index.php?s=43&item=2554 that failed to mention a fire and was clearly made by BOEING

That was a statement made a single day after the incident, and perhaps before the NTSB issued its own statement with preliminary findings. In which case no really reliable information was available - just check the first threads to see how much contradictory and incomplete info was going around. So I can't really blame Boeing for using a vague, generic term.
Basic rule : you do not act upon unreliable information.

And in any case, for that very reason, the only relevant technical information regarding these on-going issues is the information provided by the NTSB. I couldn't care less about what Boeing says in press statements

Topic: RE: FAA Grounds 787 Part 3
Username: HAWK21M
Posted 2013-01-21 02:41:37 and read 11205 times.

Quoting BLRAviation (Reply 3):
If empty flights are allowed like in the case of AI, then by the same logic, test flights should also be allowed.

Ferry flights have an inbuilt procedure with appropriate permission from Regulatory.

Topic: RE: FAA Grounds 787 Part 3
Username: abba
Posted 2013-01-21 03:22:27 and read 10954 times.

Quoting airmagnac (Reply 193):
Not necessarily, if the contents spilled in a way which does not endanger critical systems then it worked. Which seems to be the case in these 2 incidents. However it seems that preliminary observations indicate that under additonnal specific circumstances, there is a possibility of critical damage. Such possibilities have to be rigorously ruled out before the planes can fly again.
But this does not mean that the system actually failed in Boston or in Japan



I am sorry. I simply do not understand what you write here.

I think it is a known fact that batteries do from time to time break down in a way as we have seen in Boston and Japan. So systems must be in place to handle such a situation safely. The two batteries are located in different places as far as I understand. Why they broke down is as of yet unknown reasons - perhaps it is only a matter of bad luck. A lot of systems can be put in place to avoid batteries breaking down very often. But they will from time to time as I understand the discussion so far.

Now the fact that a totally foreseeable event actually happens - something that everybody - including Boeing - know will happen now and again - should not ground the 787. Either something has happened that has not been foreseen or some (containment) system didn't work as intended. If everything just did work as planed the incident shouldn't have lead to a grounding but only a new battery.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-21 03:45:58 and read 10791 times.

Quoting airmagnac (Reply 193):
contents spilled

If contents were spilled the containment has failed. To have spilled content, you don't need a containement.

Quoting airmagnac (Reply 193):
But this does not mean that the system actually failed in Boston or in Japan

Wrong. The design failed spectacularly to stay within the bounds as layed out very profoundly by the regulatory requirements.

There is a lot of wordart in these threads to play down what happened. But wordart won't impress a fire that evolves hundreds from miles away from the next airstrip.

As if anybody would really be interested to learn how well the containement would prevent spilled content and held back smoke during a 40min on board fire over the Pacific. As if the luck would not have been stressed enough...

IMO what we know is enough to admit, that neither Boeing nor the FAA have prooved to build and certify solid airborne lipo-appplications. From what we know today they can't provide valid guarantees that the today solution works safely. Because the guarantee that they gave initially has been rendered obsolete.

A lot of the initial intentions and plans have become paper waste due to real world events...

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 03:54:03 and read 10694 times.

Quoting airmagnac (Reply 193):
For the actual fire-fighting on the ground, I suggest you read the posts by rcair1
But fire-fighting on the ground and containement in flight are 2 different problems, as has already been mentioned countless times on these threads. Sure, they are related, but you can't directly apply knowledge regarding one scenario to the other

I guess you mean rcair1´s post about the low energy stored in the battery or to be more exact you little Jet-A is needed for that amount of energy. But this is not the problem imho. A lipo battery that has reached a critical state will re-ignite again even if the fire is extiguished for a moment unless either all energy and flaming content is burned or you cut it from any oxygern supply or you cool the remaining cells down. And this means cooling down an unstable cell which might be undergoing a reaction which heats itself up. I see non on-board system that can do this.

Topic: RE: FAA Grounds 787 Part 3
Username: RickNRoll
Posted 2013-01-21 03:55:05 and read 10706 times.

Quoting rheinwaldner (Reply 196):
If contents were spilled the containment has failed. To have spilled content, you don't need a containement.

There does seem to be a major disagreement here about something that I would intuitively have thought was very simple to agree on.

Topic: RE: FAA Grounds 787 Part 3
Username: nomadd22
Posted 2013-01-21 04:10:50 and read 10610 times.

Quoting BoeingVista (Reply 176):

Do the individual cells on the 787 battery have individual charging circuits?

No battery is going to have separate charging circuits for each cell, but they can have monitoring circuits for each cell. I'm gathering that Boeing didn't go that route from the reports so far, so it would take an autopsy to try and determine the sequence of events.
There are two ways a bad cell could cause overcharging and failure. A bad cell can not pass charging current as well, causing the voltage on that cell to go up and cause grief, or you can have a shorted cell, which causes the voltage on the other 7 cells to rise. "No more than 32 volts" doesn't tell you that there was no overcharging or excessive voltage.

Being old and inflexible, I'm thinking that they need to rely a little less on computer odds crunching and more on Murphy.

[Edited 2013-01-21 04:13:52]

Topic: RE: FAA Grounds 787 Part 3
Username: FlyingAY
Posted 2013-01-21 04:29:12 and read 10473 times.

Quoting airmagnac (Reply 193):
Exactly ! But that does not mean the containement failed in the 2 actual incidents

Fair enough. You were pointing out earlier that there might be differences how we interpret English language. I interpret this in a way that "resulted in release of flammable electrolytes, heat damage, and smoke" means that damage was done or it could have been done to systems or structure outside the container and that FAA is concerned about this and that in certain conditions that kind of release of flammable electrolytes might cause critical damage ("These conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment"). You might interpret this in another way.

If FAA thinks that the current situation is unsafe and warrants for grounding of the plane, I'd expect that either
1) The container failed.
2) The container did not fail, but the certification requirements were not strict enough since the resulting situation was anyway unsafe.

Note that I'm using the word unsafe as a synonym to the "conditions, if not corrected, could result in damage to critical systems and structures, and the potential for fire in the electrical compartment".

Topic: RE: FAA Grounds 787 Part 3
Username: Aquila3
Posted 2013-01-21 04:34:43 and read 10426 times.

Quoting WingedMigrator (Reply 178):
Sure you do: you've had one event per N flight hours. You have a rate from that, albeit with a wide confidence interval. Two observations will give you a tighter confidence interval, three even more, etc.

I beg to disagree.
one event only demonstrates that P(x) >0.
That was already assumed, of course.
You cannot infer (deduce statistics) about P(x) on that.

Topic: RE: FAA Grounds 787 Part 3
Username: kalvado
Posted 2013-01-21 04:35:03 and read 10607 times.

Quoting tdscanuck (Reply 174):

It's not about demonstrated effect on safety of flight, it's about demonstration of compliance with regulations. There are lots of ridiculous regulations that you still have to comply with, even if they have no direct bearing on safety of flight.

Just out of curiosity - can you give an example of such "ridiculous regulation"?
As for me, I like an example of a perfectly ridiculous regulation, which has quite a bit of logic behind once you dig deeper:
NYS requires cars to turn headlights on when windshield wipers are in use.
Logic: Wipers are on when weather is such that visibility is reduced. In such low visibility conditions oncoming cars would be much more visible with headlights on, reducing probability of an accident. Just a funny way of establishing a quite reasonable requirement, if you will.

Topic: RE: FAA Grounds 787 Part 3
Username: PlaneInsomniac
Posted 2013-01-21 05:08:36 and read 10347 times.

Quoting KC135Hydraulics (Reply 190):
But the material did not cause damage to any other major system. How was that a failure of the containment?
http://www.wordreference.com/definition/containment
http://www.wordreference.com/definition/contain
http://en.wiktionary.org/wiki/containment

So far the Downplay Crowd has worked on redefining the meanings of the words fire, smoke, safety - and now containment.

Which part of the dictionary will be rewritten next?

Topic: RE: FAA Grounds 787 Part 3
Username: breiz
Posted 2013-01-21 05:12:18 and read 10359 times.

I hope every reader will take this as a joke, even if deemed a bad one.
The B787's batteries are produced by French company Thales.
A good conspiracy theory would be that Thales is the Trojan horse used to delay the B787 in favour of the A350    .

Now on a more serious note, to burn a battery you need a serious overload.
Such a overload is usually created by the electrical system to which the battery is connected, not by the battery itself.
The FAA's review of the architecture is therefore an appropriate move.

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-21 05:18:47 and read 10258 times.

Quoting AeroWesty (Reply 159):
But there's a bigger picture here: The complexity of this problem is also raising questions about whether the F-A-A is equipped to oversee such sophisticated technology.

This is a fairly common mainstream media criticism of regulators when they are dealing with new technology. It's hardly ever fair, and to the extent that FAA lacks knowledge about the technology, they can look to other parts of the government for help (probably NASA or the Department of Energy).

Quoting DocLightning (Reply 165):
Darned right it should be grounded. The only "mishandling," if any, was that it took the FAA until the next day to ground it.

You are reading quite a bit in to the statement that was not there. The grounding isn't over yet, and I think it far more likely that folks will criticize FAA for how and when it ends than for how and when it began.

That said, if the discussions in the Japanese media about these batteries coming from a single batch turn out to be accurate, there's probably an argument to be made that the grounding of the whole fleet has already gone on too long.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 05:33:26 and read 10155 times.

For information, the actual text (from the Federal Register) of the conditions for design / installation / use of Li-Ion batteries in the 787.

WARNING: Terms such as "extremely remote", "explosion", "self-sustaining", "failure", "major or more severe failure condition", are technical terms that have a precise definition in the regulations. Wikipedia meanings are irrelevant.

"In lieu of the requirements of 14 CFR 25.1353(c)(1) through (c)(4), the following special conditions apply. Lithium ion batteries on the Boeing Model 787-8 airplane must be designed and installed as follows:

(1) Safe cell temperatures and pressures must be maintained during any foreseeable charging or discharging condition and during any failure of the charging or battery monitoring system not shown to be extremely remote. The lithium ion battery installation must preclude explosion in the event of those failures.

(2) Design of the lithium ion batteries must preclude the occurrence of self-sustaining, uncontrolled increases in temperature or pressure.

(3) No explosive or toxic gases emitted by any lithium ion battery in normal operation, or as the result of any failure of the battery charging system, monitoring system, or battery installation not shown to be extremely remote, may accumulate in hazardous quantities within the airplane.

(4) Installations of lithium ion batteries must meet the requirements of 14 CFR 25.863(a) through (d).

(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, in accordance with 14 CFR 25.1309(b) and applicable regulatory guidance.

(6) Each lithium ion battery installation must have provisions to prevent any hazardous effect on structure or essential systems caused by the maximum amount of heat the battery can generate during a short circuit of the battery or of its individual cells.

(7) Lithium ion battery installations must have a system to control the charging rate of the battery automatically, so as to prevent battery overheating or overcharging, and,

(i) A battery temperature sensing and over-temperature warning system with a means for automatically disconnecting the battery from its charging source in the event of an over-temperature condition, or,

(ii) A battery failure sensing and warning system with a means for automatically disconnecting the battery from its charging source in the event of battery failure.

(8) Any lithium ion battery installation whose function is required for safe operation of the airplane must incorporate a monitoring and warning feature that will provide an indication to the appropriate flight crewmembers whenever the state-of-charge of the batteries has fallen below levels considered acceptable for dispatch of the airplane.

(9) The Instructions for Continued Airworthiness required by 14 CFR 25.1529 must contain maintenance requirements for measurements of battery capacity at appropriate intervals to ensure that batteries whose function is required for safe operation of the airplane will perform their intended function as long as the battery is installed in the airplane. The Instructions for Continued Airworthiness must also contain procedures for the maintenance of lithium ion batteries in spares storage to prevent the replacement of batteries whose function is required for safe operation of the airplane with batteries that have experienced degraded charge retention ability or other damage due to prolonged storage at a low state of charge.

[Edited 2013-01-21 05:38:12]

[Edited 2013-01-21 05:39:02]

[Edited 2013-01-21 05:40:44]

Topic: RE: FAA Grounds 787 Part 3
Username: BlueShamu330s
Posted 2013-01-21 05:34:43 and read 10173 times.

I have tried to wade through all the threads relating to the Dreamliner, but perhaps I have missed comments about a picture which appears in this link with the description "A Japanese investigator examines a scorched fuselage on an ANA plane."

http://news.sky.com/story/1040689/dr...amliner-fire-investigation-widened



I am curious to know whether this scorching is from the inside out or from venting, and how the event can have been considered contained if such external damage was inflicted. I apologise if it has already been covered or if I am coming across as being incredibly dim.

Could someone also educate me on CFRP's resilience to such an event and whether the fuse will require remedial work or simply nothing more than "a wipe down and polish."

Rgds

Topic: RE: FAA Grounds 787 Part 3
Username: packsonflight
Posted 2013-01-21 05:50:25 and read 10031 times.

Quoting Cubsrule (Reply 205):
That said, if the discussions in the Japanese media about these batteries coming from a single batch turn out to be accurate, there's probably an argument to be made that the grounding of the whole fleet has already gone on too long.

I dont buy this single batch story.

Apparently the two burned battery are 30 numbers apart, but how big is a batch?
Most likely there are not more than 150 batteries excisting in the world, being produced over more than 5 years. 100 of them sitting in the 50 787 flying and the rest somewhere in the supply chain and spare part houses around the world.

Those batteries have limited shelve life, so nobody wants to many of them sitting around, specially for something like 30-50,000$ a pop.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-21 05:51:57 and read 10063 times.

Quoting nomadd22 (Reply 199):
No battery is going to have separate charging circuits for each cell, but they can have monitoring circuits for each cell.

Wrong. Even the most stupid charger for RC aviation which costs less than 50 bucks has a balancer. Check e.g. this device for roughly double that price:
http://www.graupner.de/fileadmin/dow...nleitungen/20060213144038_6414.pdf

The english section starts at page 16.

A balancer means, that beside measuring the voltage over each cell exactly, the charger applies differential currents in order to not overload a single cell. So as a result, each cell is treated seprately during charging.

We can safely assume that the 787 charger has a balancer, a cell temperature monitoring (I think it was confirmed by CM in an earlier thread) and normally also cell matching during battery production.

The problem is only, that this setup seems to not work properly. Something did not work as designed.

About the finding, that different reasons caused the two fires:
This is even worse, because the larger the number of actual issues, the larger the number of to be expected but still undetected flaws.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-21 06:30:41 and read 9758 times.

Quoting nomadd22 (Reply 199):
No battery is going to have separate charging circuits for each cell, but they can have monitoring circuits for each cell.

Quoting rheinwaldner (Reply 209):
Wrong. Even the most stupid charger for RC aviation which costs less than 50 bucks has a balancer. Check e.g. this device for roughly double that price:
http://www.graupner.de/fileadmin/dow...nleitungen/20060213144038_6414.pdf

The english section starts at page 16.

A balancer means, that beside measuring the voltage over each cell exactly, the charger applies differential currents in order to not overload a single cell. So as a result, each cell is treated seprately during charging.

A balancer circuit is NOT inherently the same as a separate charging circuit. The way the charger you referenced works (and in fact all hobby type chargers I'm familiar with) is that they simply pass charge current through the entire pack (one charge circuit) and then they have the ability to selectively and individually apply a load to the individual cells in order to "bleed off" some energy. Typically, the maximum bleed current per cell is some small fraction of the total charge current, so there is a fairly limited amount of capacity differential per cell that they can cope with.

Some charger designs don't have the balancer circuit integrated with the charging logic, so (again in an RC application) for example you might have a balancer doing it's best - applying a 500mA discharge against the highest cell; but if the charger is applying 5A of charge current, you've only reduced the high-voltage cell to 4.5A of effective charge current. The charger won't stop until it sees the "proper" voltage across the entire pack. This design works fine in the case of minor cell mismatch (i.e. within the balancers ability to fully cope with), but it clearly has its limits and has a potential for failure if the mismatch exceeds the balancer's ability. You could easily defeat this design - throw it a pack with a bunch of drained cells and one charged cell, and you WILL have a fire. Each and every time. Guaranteed.

More intelligent/good charger designs monitor the individual cell voltages, AND they will reduce the charge current (there is still only one charge circuit) to absolutely ensure that no single cell exceeds maximum voltage. What typically happens in this case, is the charge current is reduced down to the maximum balancer current - in the above example, the charge current reduces to 500mA, the balancer applies a 500mA load against the cell at max voltage (essentially meaning that cell is no longer charging at all) and the other cells continue to experience 500mA of charge current. This design is very resilient - if you throw it a pack with a bunch of drained cells and one charged cell, it will safely charge the entire pack without any individual cell ever exceeding it's maximum rating.

The above two examples are a bit extreme - it's rare for an RC pack to get that far out of whack, but I HAVE seen it happen.

Although the capacities are far larger on the 787, the same methods apply.

I would love to see a diagram/documentation for the 787 charger design.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-21 06:41:49 and read 9674 times.

Quoting packsonflight (Reply 208):
I dont buy this single batch story.

Apparently the two burned battery are 30 numbers apart, but how big is a batch?
Most likely there are not more than 150 batteries excisting in the world, being produced over more than 5 years. 100 of them sitting in the 50 787 flying and the rest somewhere in the supply chain and spare part houses around the world.

Those batteries have limited shelve life, so nobody wants to many of them sitting around, specially for something like 30-50,000$ a pop.

It seems possible that the individual cells in the battery may be commodity items (I don't know, it just seems logical that they might be). By "commodity item", I mean that it's possible the individual cells are used for other purposes, and are "generic" building blocks for many different types of batteries. Only once assembled into the 787 form to they become specific to the 787.

If this is true, then it's theoretically entirely possible that "Boeing 787 battery #1" has (for example) cells of sequential number 11001-11008, and "Boeing 787 battery #2" has cells of sequential number 13872-13879.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-21 06:54:12 and read 9534 times.

Quoting rheinwaldner (Reply 196):
If contents were spilled the containment has failed. To have spilled content, you don't need a containement.

Since there has already been a few references to RC lithium cell use, I'll throw one more out.

In RC, we have available what we call "LiPo sacks". Essentially, we acknowledge and accept that even under the best circumstances, sometimes "bad things happen" and our batteries will fail. So, we charge them in the LiPo sack. It is an enclosure that is solely designed to keep the flames "smothered" and "contained" inside the sack, while still allowing all the smoke and pressure to be vented (there is no attempt made to even try and control this). It's to keep our equipment, homes, etc. from burning down.

It's entirely possible that Boeing could adapt this technology. They could encase the cells in a steel enclosure (or whatever material is deemed able to 100% withstand the maximum possible energy of a failed battery without melting - the current enclosure may already satisfy this), and then have a sort of fume hood attached, such as a pipe that is several feet long and which contains baffling. It would be a sealed enclosure with the fume hood pipe as the ONLY way out. In the event of a failure of one or more cells, this would let all the pressure and smoke out, but would contain any fire / flammable substance from escaping "containment."

Just like we do in RC with our LiPo sacks.

Anyone see a reason why this idea wouldn't work? I am not a mechanical engineer (I'm a software guy by trade) but I rather like the idea.

[Edited 2013-01-21 06:57:39]

Topic: RE: FAA Grounds 787 Part 3
Username: BoeingVista
Posted 2013-01-21 07:07:17 and read 9408 times.

Quoting packsonflight (Reply 208):
I dont buy this single batch story.

Apparently the two burned battery are 30 numbers apart, but how big is a batch?

I'd be a bit sceptical too if this is how it shook out, lots of separate components will also be produced in different batches and built up into cells before being assembled in the final serial numbered battery.

Also an unanswered question is what happened to the original ANA main battery, when was it changed and why.

Topic: RE: FAA Grounds 787 Part 3
Username: RNAVFL350
Posted 2013-01-21 07:08:15 and read 9449 times.

According to the NTSB report as seen on the Aviation Herald, the flight data recorder on JA829J indicates that the nominal battery voltage of 32V was never exceeded. Does this mean that an over-charge state never existed on this battery during this particular event?

If there was no over-voltage state during this event, does this mean that they battery was being charged at its operational design, or does this just mean that 32v was never exceed, but that the battery still may have been put into an overcharge state which has been proven to cause thermal runaway?

From a containment side of things, it is surprising to see how varied the opinions are. According to some the containment worked exactly as designed, while others here seem to think that it failed "spectacularly". I am no engineer, but from viewing the photos of the burnt out battery, it seems that the event was contained quite well. Whether or not it did its job as designed is up to the engineers and regulators to decide, but from what I understand so far from the investigation, there was never any danger due to collateral damage from this event despite what some people have posted here.

Some have posted that this could be the end of the 787 program altogether if another issue arises causing yet another grounding once the current issue is resolved. Seriously? Did the 777 in 2005 not have a serious issue due to icing in the fuel system that actually ended up causing a crash in Heathrow which could have been much worse than it was? This was not an isolated incident either as it had happend to other 777's as well, only at altitude which did not cause a serious problem (excempt maybe maintaining RSVM) as they were eventually able to recover fuel flow to the engines. Pretty sure this did't even cause a grounding, and it did cause a hull loss! I suppose you will find doomsdayers in any forum on the internet.

Does anyone here know what other commercial planes use Li batteries in service? I know the A380 uses them for emergency lighting, but nothing near the capacity of the 787. I also beleive the A350 (currently anyway) intends to use them, pending the outcome of the investigation I suppose.

Thanks all and really enjoy all the comments and information here on a.net. Especially from CM, Tdscancuk, Stitch, Lightsabre, Revelation and a few others who really seem to be at the heart of the aviation industry.

Paul

Topic: RE: FAA Grounds 787 Part 3
Username: tdscanuck
Posted 2013-01-21 07:11:45 and read 9453 times.

Quoting BoeingVista (Reply 176):
Do the individual cells on the 787 battery have individual charging circuits?

I don't know.

Quoting BoeingVista (Reply 176):
What if any systems or capabilities does the 787 lose if it loses the main battery?

If the main battery is lost while the airplane is powered down, you can't power up. If it's powered up, the airplane will continue to run on whatever generator sources it has (ground power, any of 4 engine generators, or any of 2 APU generators, or the RAT). If all generator sources fail and the main battery fails, the airplane will go dark except for emergency lighting systems (which have their own internal batteries).

Quoting WingedMigrator (Reply 178):
Quoting tdscanuck (Reply 174):
you don't get any rate data off a single event.

Sure you do: you've had one event per N flight hours. You have a rate from that, albeit with a wide confidence interval. Two observations will give you a tighter confidence interval, three even more, etc.

By "wide confidence band" you mean the variance is infinity...you don't get any rate data because you have no confidence interval at all. Suppose you have a part that really does have a failure rate of 1 per 1 million flight hours. After 1000 flight hours you have a failure...that's completely consistent with one failure you expected and you're good for another 999,000 flight hours (statistically speaking).

Quoting seahawk (Reply 181):
An in-flight fire which can not be put down by any means available on the plane is a huge risk.

Not if the energy is contained, that's the whole point. The batteries are, by design, located in compartments where there is nothing else to burn and they restrict the damage to the battery itself. They don't have infinite energy capacity, they will burn themselves out without breaching containment.

Quoting seahawk (Reply 181):
Just read up how long the fire department in Boston needed to kill the fire and how hard it is to kill such a battery fire, this is a big problem for an ETOPS180 or ETOPS 120 plane.

There's a major repeated confusion going on here...the Boston ARFF extinguished the battery 40 minutes after the fire was reported to them. They did *not* fight the battery fire for 40 minutes.

Quoting seahawk (Reply 181):
The battery should not ignite and it should not spill its contents, which means that the containment also failed.

That's a misunderstanding about what "containment" means in this context. The design contains the damage. It's written right into the FAA special condition...gases and electrolyte do not need to be physically kept inside the battery box, they must be prevented from causing meaningful damage to other equipment. It's somewhat similar to fire containment in large buildings...the requirement is that the fire can't cause damage to the evacuation routes (typically stairwells and elevator cores) for a proscribed period of time, *not* that smoke can't come out of the building. The aircraft equivalent is to keep the damage inside the battery box and safely vent the fire products out of the airplane. Based on all evidence we have from both events, that happened. There may be investigation results that show that damage *did* occur to other aircraft systems but I have never seen any reports of that yet. It's the latter that would mean the containment failed.

Quoting packsonflight (Reply 184):
"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"

I see no argument here!

There is nothing about the regulations or special conditions that says electrolytes or smoke must stay inside the battery box. It's a vented box, so it's pretty obvious it wasn't designed to do that. The regulations say the fire can't spread (it didn't), that smoke can't enter the passenger compartment or flight deck in flight (in didn't), and that the fire can't cause damage (loss of function) to other equipment...and it didn't. It's certainly possible that the NTSB/FAA will find some way it could but claims that it *did* seem to be erroneous.

Quoting seahawk (Reply 186):
One solution could be putting the batteries in similar bags and adding a Halon injection system that fills the bag in case of a runaway cell.

Wouldn't work...lithium battery fires are self-sustaining once they get going.

Quoting RickNRoll (Reply 189):
Smoke and flammable material were not contained, and posed a potential hazard to other aircraft systems. You could say that nothing was damaged by the "containment" that is being disputed, but the FAA feels it is not satisfactory in that it could have damaged important systems.

Smoke and flammable materials were not contained *within the battery box*, nor were they required to be. The FAA's statement that it could have (not did) damage other systems is the important part.

Quoting abba (Reply 192):
I find your argument basically flawed. The fact that the material didn't actually cause damage to any other system doesn't mean that the containment didn't fail. The very fact that the material left the container means that it wasn't contained.
Quoting rheinwaldner (Reply 196):
If contents were spilled the containment has failed.

That's not what fire containment means. The battery box has vents and always has...that tells you right off that bat that the system was never designed for physical containment of all products within the battery box.

Quoting abba (Reply 195):
Now the fact that a totally foreseeable event actually happens - something that everybody - including Boeing - know will happen now and again - should not ground the 787. Either something has happened that has not been foreseen or some (containment) system didn't work as intended. If everything just did work as planed the incident shouldn't have lead to a grounding but only a new battery.

The problem is the rate...batteries aren't supposed to catch fire this often. This means all the fault trees with "battery fire" in them are potentially using the wrong probability, which rolls up into the higher level probabilities of serious or catastrophic events. Until they re-evaluate those possible effects and probabilities, they don't know if they actually meet the regulations.

Quoting rheinwaldner (Reply 196):
As if anybody would really be interested to learn how well the containement would prevent spilled content and held back smoke during a 40min on board fire over the Pacific.

Smoke containment is proven (by actually putting smoke in the bays) for considerably longer than 40 minutes during certification, so we know that actually works. Spilled content is fine per the regulation as long as it doesn't damage other systems. Unless I missed a report somewhere, it didn't damage any other systems.

Quoting kalvado (Reply 202):
Quoting tdscanuck (Reply 174):
It's not about demonstrated effect on safety of flight, it's about demonstration of compliance with regulations. There are lots of ridiculous regulations that you still have to comply with, even if they have no direct bearing on safety of flight.

Just out of curiosity - can you give an example of such "ridiculous regulation"?

My poster child example is the requirement for ashtrays on the lav doors...it's a holdover from when smoking was allowed on flights. Ostensibly, it's still required so that *even* if someone ignores the warnings *and* disables the smoke detectors *and* the lav fire extinguishing fails or they don't actually dispose of the cigarette in the trash, *then* you still have a "safe" place to put it out. Apparently, the sink and toilet are not viable options to extinguish a single cigarette.

Tom.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 07:27:34 and read 9333 times.

Quoting BoeingVista (Reply 213):
Also an unanswered question is what happened to the original ANA main battery, when was it changed and why.

Japanese media reported it was removed because when they tried to start the engines using the battery, it didn't work. However, the Ships Battery is not used to start the engines. Perhaps they meant starting the APU (the Ship's and APU battery work together to start the APU, though the APU battery can do it on it's own if necessary).

Topic: RE: FAA Grounds 787 Part 3
Username: nomadd22
Posted 2013-01-21 07:33:02 and read 9228 times.

Quoting rheinwaldner (Reply 209):
Wrong. Even the most stupid charger for RC aviation which costs less than 50 bucks has a balancer. Check e.g. this device for roughly double that price:
http://www.graupner.de/fileadmin/dow...nleitungen/20060213144038_6414.pdf

The english section starts at page 16.

A balancer means, that beside measuring the voltage over each cell exactly, the charger applies differential currents in order to not overload a single cell. So as a result, each cell is treated seprately during charging.

We can safely assume that the 787 charger has a balancer, a cell temperature monitoring (I think it was confirmed by CM in an earlier thread) and normally also cell matching during battery production.

The problem is only, that this setup seems to not work properly. Something did not work as designed.

About the finding, that different reasons caused the two fires:
This is even worse, because the larger the number of actual issues, the larger the number of to be expected but still undetected flaws.

That link says no such thing and there's no "differential currents" supplied to individual cells. In fact the charger is only made for a single lithium cell. The pdf in the link instructs you to remove the individual cells and discharge them on their own in order to balance them. The only multi cell balancing in the average charger is a higher voltage applied on occasion to force current through after the point most of the cells are fully charged in order to bring weaker cells up.
You can assume whatever you want, but poor cell matching is a definite suspect in this whole thing. And there's no reason to believe that Boeing has included the ability to monitor and disconnect individual cells in a series. Maybe they do, but from the reports so far, it doesn't look like it.

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-21 08:14:19 and read 8837 times.

Quoting rheinwaldner (Reply 167):
Thanks, so we now know that a single cell died and did run away thermally. I also have to say that 8 cells is not much for such a high capacity. Why the selection of high currents instead of higher voltages?

A nominal voltage of 28V DC (usually specified as 24-32V range) is a standard for aircraft electrical systems. It's something of a compromise between the larger conductors that would be needed at lower voltages, and the more heavily insulated conductors that would be needed at higher voltages. It was also a convenient voltage for the electro-mechanical avionics systems back in the day. (Not so much for modern electronics, actually, but...)

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 08:19:18 and read 8808 times.

Quoting tdscanuck (Reply 215):


There's a major repeated confusion going on here...the Boston ARFF extinguished the battery 40 minutes after the fire was reported to them. They did *not* fight the battery fire for 40 minutes.

So what where the firemen doing in those 40 minutes? Wait to see if the whole plane will catch fire or maybe it was the more likely situation that they had to "control" the fire until the battery burned itself out, as they had no means to extinguish the fire within the plane, which would not cause excessive damage.

The report also mentions slight damage to the surroundings of the battery - slight damage even though the fire was quickly detected and fire crews arrived on scene quickly. It is every ones guess on how that would have gone 3 hours out over the Pacific. I am asking myself if such a fault would have caused the other batteries to overheat, which would easily cause the same failure on those and a nasty chain reaction.

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-21 08:20:07 and read 8807 times.

Quoting nomadd22 (Reply 217):
That link says no such thing and there's no "differential currents" supplied to individual cells. In fact the charger is only made for a single lithium cell. The pdf in the link instructs you to remove the individual cells and discharge them on their own in order to balance them. The only multi cell balancing in the average charger is a higher voltage applied on occasion to force current through after the point most of the cells are fully charged in order to bring weaker cells up.
You can assume whatever you want, but poor cell matching is a definite suspect in this whole thing. And there's no reason to believe that Boeing has included the ability to monitor and disconnect individual cells in a series. Maybe they do, but from the reports so far, it doesn't look like it.

From the looks of that PDF, you're correct, that particular charger has no built-in balancing abilities. It's probably a several year old design - almost all the modern stuff has built in balancing. Modern lithium packs for RC use have a balancing tap - a second connector with a wire to every individual cell so that the pack can be balanced/monitored etc. per individual cell. Many chargers won't even work without it connected for safety reasons. I can't read German so I can't comment any further on that charger.

A "higher voltage applied on occasion" might work for lead acid, NiCd, NiMH type technologies (where excess energy can (to an extent) be safely dissipated as excess heat, but it's absolutely not possible on Lithium cells. Lithium cells can not dissipate excess energy in this manner. They absorb it until they fail. That's why you can't trickle charge them - you can trickle charge a NiCd indefinitely and it will just stay a little warm (excess energy converting to heat), try that with a lithium cell and it will fail.

The way balancing is done with all balancing chargers I'm familiar with, is to impart a load (resistance) across an individual cell to bleed off energy to maintain the desired voltage. On the charger I use, the balancer is active throughout the entire charge profile - if one cell is 0.05V higher than another midway through the charge profile (but all cells are at completely safe voltage), it will still balance the high cell down, instead of waiting until the very end to limit the cell to 4.2V.

I would agree that cell matching/balancing is definitely an area of interest. I really want to believe that Boeing has experts dedicated to this very topic (how could they not?!), but the NTSB's assertion that the battery never overcharged because it never went over 32V really bugs me. The only proper way to determine that no overcharge took place is to verify that none of the individual cells ever exceeded the maximum safe per-cell voltage.

Stating that the battery never exceeded 32v is absolutely meaningless and tends to imply that no other metric was available.

I hope they are just "dumbing down" their presentation.

Topic: RE: FAA Grounds 787 Part 3
Username: cornutt
Posted 2013-01-21 08:26:49 and read 8724 times.

Quoting RNAVFL350 (Reply 214):
If there was no over-voltage state during this event, does this mean that they battery was being charged at its operational design, or does this just mean that 32v was never exceed, but that the battery still may have been put into an overcharge state which has been proven to cause thermal runaway?

IIRC the report said that the data in question came from the flight data recorder. On a modern aircraft, the FDR only records a small subset of the available data. The aircraft's maintenance system maintains a lot more data parameters, at higher sampling rates, and it probably has data on the individual cell temperatures and voltages. I don't know how long it would take to wade through all of that.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 08:28:44 and read 8720 times.

Quoting nomadd22 (Reply 217):
there's no reason to believe that Boeing has included the ability to monitor and disconnect individual cells in a series

Or that they (meaning Yuasa, Securaplane, Thales - not just Boeing, or even primarily Boeing) have not, given the regulatory conditions:

Quoting Kaiarahi (Reply 206):
Safe cell temperatures and pressures must be maintained during any foreseeable charging or discharging condition
Quoting Kaiarahi (Reply 206):
Lithium ion battery installations must have a system to control the charging rate of the battery automatically
Quoting Kaiarahi (Reply 206):
A battery temperature sensing and over-temperature warning system with a means for automatically disconnecting the battery from its charging source in the event of an over-temperature condition, or,

(ii) A battery failure sensing and warning system with a means for automatically disconnecting the battery from its charging source in the event of battery failure.


The prototype was described by the Admin Law Judge hearing a suit against Securaplane as having "a signal connector made to connect with the BCU with roughly 20 to 30 interface signals that go between the two".

[Edited 2013-01-21 08:42:36]

Topic: RE: FAA Grounds 787 Part 3
Username: PHX787
Posted 2013-01-21 08:30:32 and read 8765 times.

Hey guys, some more news from Japan today:

ANA reportedly cancelled 355 flights and the JMoT will have the Dreamliner grounded until at least* the 27th

*I say at least, which wasn't mentioned in the article, because of course they cannot unground the plane until the FAA gives the go-ahead.

http://www.japantoday.com/category/b...-due-to-dreamliner-fleet-grounding

Many thousands of pax are stranded which makes me wonder how they are being accommodated?


-Zach

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 08:35:23 and read 8679 times.

Quoting seahawk (Reply 219):
So what where the firemen doing in those 40 minutes?

They had to suit up and drive to the plane. They had to determine if there was anyone aboard the aircraft. Once they determined nobody was, that immediately lowered the sense of urgency. So they then determined what was happening. During that process, they determined they were dealing with a Class D fire and that their extinguishing agents they could deploy inside the bay would be ineffective. They then had to determine how to remove the battery from the plane so they could apply the appropriate agent to extinguish it. They then had to identify who would go into the bay. I imagine the bay is not designed for a fireman with self-contained breathing apparatus to easily enter, easily exit, or move freely around in so that took time to enter. There were claims of "two foot high flames" coming out of the vents on the box, so they apparently applied some type of agent to control those flames to allow them to remove the box from it's mounts and take it outside. They then had to carry the box away from the plane to an area to apply the necessary agents to extinguish the Class D fire.

Forty minutes does not strike me as an unreasonable timeframe to do this, especially when the emphasis is on the safety of the firefighters and not the airframe because there was nobody aboard.

[Edited 2013-01-21 08:52:17]

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 08:45:45 and read 8547 times.

Quoting Stitch (Reply 224):

   rcair1 (a firefighter) posted an excellent analysis in an earlier thread of the challenges and decisions.

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 08:48:59 and read 8477 times.

Quoting Stitch (Reply 224):

They had to suit up and drive to the plane. They had to determine if there was anyone aboard the aircraft. Once they determined nobody was, that immediately lowered the sense of urgency. So they then determined what was happening. During that process, they determined they were dealing with a Class D fire and that their extinguishing agents they could deploy inside the bay would be ineffective. They then had to determine how to remove the battery from the plane so they could apply the appropriate agent to extinguish it. They then had to identify who would go into the bay. I imagine the bay is not designed for a fireman with self-contained breathing apparatus to enter, exit, or move freely around in so that took time to enter. There were claims of "two foot high flames" coming out of the vents on the box, so they apparently applied some type of agent to control those flames to allow them to remove the box from it's mounts and take it outside. They then had to carry the box away from the plane to an area to apply the necessary agents to extinguish the Class D fire.

Forty minutes does not strike me as an unreasonable timeframe to do this, especially when the emphasis is on the safety of the firefighters and not the airframe because there was nobody aboard.

And how does that conflict with my first post, that no means available on the plane could have handled the fire and that the battery seemed to have burned (more or less) for around 50 minutes at least? I just wanted to point out that getting the battery fire out is not a simple shot with a normal fire extinguisher or a normal dose of Halon. I had no intention to blame the fire crews for anything, just say that this is not an easy fire to put down, even thought it was limited in size.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-21 08:49:37 and read 8630 times.

Quoting nm2582 (Reply 210):
A balancer circuit is NOT inherently the same as a separate charging circuit.

The main current goes through all cells in series, that's correct. But the balancing currents still mean, that each cell "sees" an own, independent charging circuit.

The balancer does treat each cell separately and allows to balance the voltage as it builds up over each single cell. Of course and as you explain very well, there are limits on the hobby chargers. But even if the balacing currents are limited (about 20mA in many typical devices IIRC), the charger can still stop charging at all, if the applied differential current no longer allows to keep the voltage over a troubled cell in a safe region.

I would expect on the other hand from the 787 unit to have balacing currents that are not limited....

Topic: RE: FAA Grounds 787 Part 3
Username: nm2582
Posted 2013-01-21 08:55:23 and read 8572 times.

On the topic of how long it took to put the fire out:

Keep in mind that a lithium "battery" does not burn up all at once (all cells do not burn down at the same moment). It's comprised of individual cells, and frequently you will see a failure that goes something like this:

One single cell (let's call it #1) fails for whatever reason, and it emits a large amount of heat in a short timeframe (measured in seconds, not minutes). The cell nearest to the failed cell absorbs enough heat to induce a thermal runaway, but it takes a few minutes to occur. Let's call this cell #2.

When cell #2 fails a few minutes later and emits a large amount of heat, yet another cell is forced into thermal runaway, which again takes a few minutes to occur.

The process can repeat several times over as each individual cell fails in its own time. The amount of physical barrier (if any) between cells, the distance between cells, the thickness of the cell casing, etc. etc. all play roles here in determining how long it takes for the cells to fail like this.

So, it's entirely possible that the firefighters knew this, and for the most part let the battery fully fail (i.e. wait until all cells are burned up and failed) while keeping a watching eye on the situation to verify nothing else is set on fire.

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-21 09:06:35 and read 8452 times.

Quoting RickNRoll (Reply 198):
something that I would intuitively have thought was very simple to agree on.

This is aviation. Very little about it is intuitive. Even the basic properties of a wing are not intuitive (see the opening paragraph of W. Langewiesche's "Stick and Rudder" (1944)).
And complex, integrated, coupled, layered critical systems are certainly NOT intuitive.

Quoting PlaneInsomniac (Reply 203):
the Downplay Crowd
Quoting rheinwaldner (Reply 196):
There is a lot of wordart in these threads to play down what happened

Just to be clear : the events themselves are not being downplayed by anyone, they have consistently been described as serious, abnormal and to be fixed.
What is being nuanced is some of the interpretations given on this board of the events, of the relevant requirements and of the statements by Boeing, the FAA and the NTSB

And this is not a question of downplaying or minimising events because it's my favourite company in the world.

Personnally, if I had to choose between being pro- or anti-Boeing, I'd definitly choose the "anti" side. If this 787 issue brings Boeing down then my employer has a monopoly on the large airliner market, and I can hope to be paid a fortune while working only 2h a day making crap airplanes. Yipeeee !

But I don't reason in such emotional pro-Boeing/anti-Boeing terms. We're talking about safety here. That requires rational thinking and a no-nonsense approach to the problem. It also requires some subtlety in our representation of reality to preserve both safety and performance ; simplistic thinking on the lines of "it's either good or bad", or "safe/unsafe", are just not accurate enough.

Topic: RE: FAA Grounds 787 Part 3
Username: rheinwaldner
Posted 2013-01-21 09:15:16 and read 8329 times.

Quoting RNAVFL350 (Reply 214):
According to the NTSB report as seen on the Aviation Herald, the flight data recorder on JA829J indicates that the nominal battery voltage of 32V was never exceeded. Does this mean that an over-charge state never existed on this battery during this particular event?

No, it is meaningless. While total voltage is still 32V any cell could produce fireworks.

Quoting tdscanuck (Reply 215):
They don't have infinite energy capacity, they will burn themselves out without breaching containment.

Was this tested within an actual fuselage section?

Quoting tdscanuck (Reply 215):
...the Boston ARFF extinguished the battery 40 minutes after the fire was reported to them. They did *not* fight the battery fire for 40 minutes.

So the battery burned for more than 40 minutes.

Quoting tdscanuck (Reply 215):
Quoting rheinwaldner (Reply 196):
If contents were spilled the containment has failed.

That's not what fire containment means. The battery box has vents and always has...that tells you right off that bat that the system was never designed for physical containment of all products within the battery box.

So you claim, that the spilled content in this case does not warrant some attention?

Quoting nomadd22 (Reply 217):
In fact the charger is only made for a single lithium cell

Oops, you are right, I was 100% sure because I have the Ultramat 14. But ... it turned out that I have the Ultramat 14 plus. Here is the right docu:
http://www.graupner.de/mediaroot/fil...4_Ultramat_14_plus_de_en_fr_it.pdf

But everything that I said is valid.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 09:16:16 and read 8320 times.

Quoting seahawk (Reply 226):
And how does that conflict with my first post, that no means available on the plane could have handled the fire and that the battery seemed to have burned (more or less) for around 50 minutes at least?

First, do we know for a fact that the battery was burning for close to an hour by the time it was removed from the airplane? Yes, people reported a smell almost an hour before then, but when dealing with electrical components, one does not have to have a fire in order to generate a smell.

Second, there is no means aboard to extinguish the fire. That is not the same as saying there was no means to handle it. That was what the containment box was for and it does appear to have been handling it - perhaps for as long as an hour - based on the physical evidence showing the rest of the EE bay was not on fire. And with the physical evidence showing the containment box was intact, it appears to have been able to continue to handle the fire for an even longer period of time.

As to what constitutes the containment box "handling" the fire, that has been stated multiple times in multiple threads by multiple people with direct knowledge - and understanding - of the relevant FARs and Special Conditions. It is quite clear from their postings that a number of people on this forum do not understand those FARs and Special Conditions - that or they are just willfully trolling the thread to advance a personal agenda / vendetta. Some may be reading the text and assuming things based on their own experiences - experiences not related to commercial aviation. And while the discussion of those experiences can in cases add context to the main discussion, they should not be treated as if they were directly relevant to the main discussion.

[Edited 2013-01-21 09:35:01]

Topic: RE: FAA Grounds 787 Part 3
Username: Skydrol
Posted 2013-01-21 09:23:08 and read 8255 times.

Quoting airmagnac (Reply 229):
If this 787 issue brings Boeing down then my employer has a monopoly on the large airliner market, and I can hope to be paid a fortune while working only 2h a day making crap airplanes.

Well, thank you for being honest about your products. Many of us have suspected this for some time, but finding out from an 'insider' confirms it.  




✈ LD4 ✈

Topic: RE: FAA Grounds 787 Part 3
Username: TheSultanOfWing
Posted 2013-01-21 09:39:46 and read 8082 times.

Quoting BlueShamu330s (Reply 207):

"A Japanese investigator examines a scorched fuselage on an ANA plane."

http://news.sky.com/story/1040689/dr...amliner-fire-investigation-widened

I am curious to know whether this scorching is from the inside out or from venting, and how the event can have been considered contained if such external damage was inflicted. I apologise if it has already been covered or if I am coming across as being incredibly dim.

Could someone also educate me on CFRP's resilience to such an event and whether the fuse will require remedial work or simply nothing more than "a wipe down and polish."

Rgds

Isn't the above pretty significant?


FH

Topic: RE: FAA Grounds 787 Part 3
Username: BlueShamu330s
Posted 2013-01-21 09:48:36 and read 7961 times.

Quoting TheSultanOfWing (Reply 233):
Isn't the above pretty significant?

I'm please someone else asked; I'm hopeful someone might yet be able to shed some light on it !

Rgds

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 09:49:23 and read 8024 times.

Quoting BlueShamu330s (Reply 207):
I have tried to wade through all the threads relating to the Dreamliner, but perhaps I have missed comments about a picture which appears in this link with the description "A Japanese investigator examines a scorched fuselage on an ANA plane."

I am curious to know whether this scorching is from the inside out or from venting, and how the event can have been considered contained if such external damage was inflicted.

Electrolyte solution was vented out of the EE bay and was deposited on the side of the fuselage, so this might be what they're referring to and showing a picture of. We know the EE bay did not catch on fire, so it cannot be a case of such a fire burning through the EE bay walls and coming into contact with the fuselage skin.

As to the containment angle, the box is not designed to be a Level 10 containment field from Star Trek: The Next Generation, even if a literal reading of the Special Conditions with no context as to what the FAA intended could create such a belief that it was. It is designed to allow gases and materials to vent from it because if it did not, then it could become an explosive device. And I would like to believe that the FAA would not sign-off on the installation of a bomb.  Silly

[Edited 2013-01-21 09:53:38]

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-21 09:54:23 and read 7955 times.

Quoting TheSultanOfWing (Reply 233):
Isn't the above pretty significant?

It would be significant if it were true. However, the JTSB already released a statement saying the streaking on the outside if the fuselage near the vents was liquid material from the battery. The fact a journalist decided to use the word "scorched" seems incorrect in light of the JTSB statement.

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 09:54:49 and read 7929 times.

Quoting Stitch (Reply 231):
First, do we know for a fact that the battery was burning for close to an hour by the time it was removed from the airplane? Yes, people reported a smell almost an hour before then, but when dealing with electrical components, one does not have to have a fire in order to generate a smell.

Second, there is no means aboard to extinguish the fire. That is not the same as saying there was no means to handle it. That was what the containment box was for and it does appear to have been handling it - perhaps for as long as an hour - based on the physical evidence showing the rest of the EE bay was not on fire. And with the physical evidence showing the containment box was intact, it appears to have been able to continue to handle the fire for an even longer period of time.

As to what constitutes the containment box "handling" the fire, that has been stated multiple times in multiple threads by multiple people with direct knowledge - and understanding - of the relevant FARs and Special Conditions. It is quite clear from their postings that a number of people on this forum do not understand those FARs and Special Conditions - that or they are just willfully trolling the thread to advance a personal agenda / vendetta. Some may be reading the text and assuming things based on their own experiences - experiences not related to commercial aviation. And while the discussion of those experiences can in cases add context to the main discussion, they should not be treated as if they were directly relevant to the main discussion.

There I do respectfully disagree. The plane at Boston showed burn marks outside the box and the fire was monitored and probably controlled by the fire fighters for the majority of the probably burn time. I am quite certain that they will have made sure to cool the other batteries in the rack to avoid a chain reaction. (Those batteries can get critical at 70-90°C not that much considering how close the packs are mounted)
The plane in Japan had the contents of the battery leak out of the battery onto the floor and out of the plane.

Although not working in aviation, but being used to asses the potential risk of hazard material storages for chemical industries at work, I have doubts that this leakage was designed to happen.

I am aware of the design requirements of the containment, I am not convinced that it is working as intended though.

Topic: RE: FAA Grounds 787 Part 3
Username: Humanitarian
Posted 2013-01-21 10:00:10 and read 7819 times.

Quoting tdscanuck (Reply 215):
Quoting tdscanuck (Reply 215):
My poster child example is the requirement for ashtrays on the lav doors...it's a holdover from when smoking was allowed on flights. Ostensibly, it's still required so that *even* if someone ignores the warnings *and* disables the smoke detectors *and* the lav fire extinguishing fails or they don't actually dispose of the cigarette in the trash, *then* you still have a "safe" place to put it out. Apparently, the sink and toilet are not viable options to extinguish a single cigarette.

Correct - not having an ashtray inside the lav is a 'no-go' item: You cannot MEL it. I ran into this scenario more than once. It can be missing from outside the lav but not inside. If you do not have one in stock, the solution was to take the one outside the lav and put it 'inside' and then MEL the outside ashtray. Another oddball no-go item found on the Airbus is the pilots sunvisor. If broken, the plane is grounded until it is repaired or replaced. Also got burned on that one.

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-21 10:03:53 and read 7831 times.

Quoting seahawk (Reply 237):
the other batteries in the rack

There are no other batteries in the rack, or the aft bay at all, for that matter.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 10:07:10 and read 7743 times.

Quoting seahawk (Reply 237):
I am quite certain that they will have made sure to cool the other batteries in the rack to avoid a chain reaction.

What other batteries are in the aft bay?

Topic: RE: FAA Grounds 787 Part 3
Username: AeroWesty
Posted 2013-01-21 10:07:39 and read 7750 times.

Quoting PHX787 (Reply 223):
Many thousands of pax are stranded which makes me wonder how they are being accommodated?

The article you linked doesn't use the word "stranded", it uses the word "affected". ANA has been reaccommodating passengers on flights with replacement equipment. Very few flights are actually being cancelled, in the grand scheme of things.

See: http://www.ana.co.jp/topics/notice130116/index_list_e.html

Topic: RE: FAA Grounds 787 Part 3
Username: justloveplanes
Posted 2013-01-21 10:09:51 and read 7720 times.

Quoting seahawk (Reply 237):
I am aware of the design requirements of the containment, I am not convinced that it is working as intended though.

I have to agree. The electrolyte leakout must have been a surprise (burnout containment seemed to work), I can't imaging spilling on to the floor was an acceptable scenario to the designers, and one pretty easy to correct with a larger vessel I would think.

So something like fluids boiling over must have happened, like when you fill something to full in the microwave...

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-21 10:11:35 and read 7720 times.

Quoting Skydrol (Reply 232):
Quoting airmagnac (Reply 229):
If this 787 issue brings Boeing down then my employer has a monopoly on the large airliner market, and I can hope to be paid a fortune while working only 2h a day making crap airplanes.

Well, thank you for being honest about your products. Many of us have suspected this for some time, but finding out from an 'insider' confirms it.

  
Well now, I would have to slightly correct your interpretation of that sentence becau... ... ... oh hell, whatever  

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 10:30:43 and read 7543 times.

Quoting seahawk (Reply 237):
There I do respectfully disagree. The plane at Boston showed burn marks outside the box and the fire was monitored and probably controlled by the fire fighters for the majority of the probably burn time.

Yes it did. In a very small area, mostly where the battery box was in direct contact. So thermal heating of the containment box resulted in thermal heating and charring of the area that the box was in contact with.

Even the most cursory examination of the photo of the aft EE bay shows that most of it was untouched by fire nor was it exposed to sufficient thermal energy to char, melt or cause discoloration.



Quoting seahawk (Reply 237):
The plane in Japan had the contents of the battery leak out of the battery onto the floor and out of the plane.

Yes it did. And it leaked out of the aircraft via an outflow valve, not by burning/corroding itself through the floor of the EE bay and then the fuselage like the blood of the creatures in the fictional Alien universe. As such, I believe the question to ask is "what was the purpose of that outflow valve"? Was it the one designed to ventilate smoke and gasses from the EE bay and air flow caused the electrolyte to be expelled as well? Or was that outflow valve there to vent electrolyte in the event it spilled out of the containment box?



Quoting justloveplanes (Reply 242):
The electrolyte leakout must have been a surprise (burnout containment seemed to work), I can't imaging spilling on to the floor was an acceptable scenario to the designers, and one pretty easy to correct with a larger vessel I would think.

It was a surprise only if the regulators, Boeing, and the sub-contractors never believed a battery could leak. And if they all believed that, I would think that would have precluded them from designing a containment box in the first place.

That being said, I do agree with you that a second box surrounding the primary box seems prudent - kind of like a "double-hull" on an oil tanker.

Topic: RE: FAA Grounds 787 Part 3
Username: Braybuddy
Posted 2013-01-21 10:34:14 and read 7500 times.

I think we're beginning to enter the realm of Alice in Wonderland in these threads: "When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean -- neither more nor less."  

Topic: RE: FAA Grounds 787 Part 3
Username: kanban
Posted 2013-01-21 10:47:46 and read 7358 times.

Quoting nomadd22 (Reply 199):
Being old and inflexible, I'm thinking that they need to rely a little less on computer odds crunching and more on Murphy.

ditto

Quoting rheinwaldner (Reply 230):
No, it is meaningless.

if the information removes, clarifies or indicates a path toward resolution, it is hardly meaningless... however I get your point that this tidbit isn't the keystone they're looking for.

for all the talk about the term "containment" nobody (well Tom and CM might but can't talk about it) knows what the pass fail criteria were written into the spec. We know there is venting capability to prevent gas buildup, we know there was an exit path for the excreted material, we know one vessel received a fireman's axe blow and subsequently showed more smoke residue, while the second was wrapped in plastic and carried out shows more dripping molasses.

So did it fail? maybe/ maybe not since we don't know the design criteria.. and to use our own interpretation of 'containment' as a basis for criticism just muddies the waters. We all want to be right in our opinions, however we need more facts first. like the one person, who maintained that these incidents proved CFRP was a bad material for aircraft, had a righteous opinion totally unsupported by the incident facts so he twisted them to support his opinion.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 11:03:06 and read 7221 times.

Quoting Braybuddy (Reply 245):
"When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean -- neither more nor less."

When a doctor says "transmural myocardial infarction", that's exactly what s/he means, and s/he's distinguishing it from a subendocardial infarction. If s/he added "acute", it adds further meaning. "Heart attack" does none of these things.

Believe it or not, aeronautical systems engineering is also a profession with its own precise terminology. Regulators also define and use that terminology to refer to specific actions and states. Hence, when a regulator uses terms such as "extremely remote", "explosion", "self-sustaining", "failure", "major or more severe failure condition" in a regulation addressed to the professional community of aeronautical engineers, it is using them as technical terms which have a defined and precise meaning that is understood by the professionals to whom they are addressed. What Wikipedia or a non-professional non-engineer thinks they might mean is irrelevant - fortunately.

Topic: RE: FAA Grounds 787 Part 3
Username: Stitch
Posted 2013-01-21 11:23:46 and read 7061 times.

Quoting Braybuddy (Reply 245):
I think we're beginning to enter the realm of Alice in Wonderland in these threads: "When I use a word," Humpty Dumpty said in rather a scornful tone, "it means just what I choose it to mean -- neither more nor less."   


Napoleon Bonaparte is quoted as having said "Never ascribe to malice that which is adequately explained by incompetence."

Though in this thread, I believe it's ignorance (willful, in some cases) as opposed to incompetence behind the posts.

Topic: RE: FAA Grounds 787 Part 3
Username: Kaiarahi
Posted 2013-01-21 11:28:34 and read 6965 times.

Quoting Stitch (Reply 248):

Ah yes. The second state of knowledge is knowing what you don't know.

Topic: RE: FAA Grounds 787 Part 3
Username: rcair1
Posted 2013-01-21 11:33:00 and read 6930 times.

Quoting JoeCanuck (Reply 60):
Look at cars...every year, we get more airbags, bigger crumple zones and still people die.

I agree with you - but I would point out that in my career of responding to car crashes, I've seen a dramatic improvement from terms of survivablity and injury rate.
Same with planes.
Which is why smart people are working in determining the seriousness of this issue, and actions that may or may not be taken to address them.

Quoting KC135Hydraulics (Reply 68):
What an eery coincidence these events occured so close to one another in such a similar fashion.

Not really. As somebody posted (CM?) - the failure mechanism for Li-Ion Batteries is the same regardless of the cause. So if the battery goes - you get this result.
Also- some of us don't believe in coincidences. Something caused both failures. We don't know what caused them, or if the cause was related or the same.

Quoting bonusonus (Reply 69):
Finally, it's been mentioned in earlier posts, but, just because overcharging let to the thermal runaway, that doesn't mean that a manufacturer's defect can't also be involved, right?

We don't know that there was overcharging or a manf defect, either or both.
Everything you read here, in terms of cause an effect, is speculation.

Quoting bonusonus (Reply 69):
Could these batteries be more susceptible to runaway from a level of overcharging that was within normal design limits?

Yes - but we do not have any data on that yet. (maybe NTSB or somebody inside does - "we" do not).

Quoting prebennorholm (Reply 75):
Then they can demonstrate for the FAA a forced in-flight battery fire, land, exchange the battery container and its contents, and take off again.

It does not need to be in-flight.

Quoting RickNRoll (Reply 79):
What has to be fixed?

That is what the investigation is looking for/at.

Quoting wjcandee (Reply 97):
although the fact that Leon wasn't using the signalling harness on the battery when it went up may have contributed, as the charger (and he) couldn't monitor the battery condition while charging.

Yes. Pretty clearly - if monitoring cell voltage is considered required during cell charging - and you disconnect that - well, "why do I need to wear that seatbelt?"

Quoting AeroWesty (Reply 162):
The investigation has barely begun. If I'm reading things right, it's still possible that the design is solid, but the execution of it was faulty. Or is that completely off the mark?

Yes, Yes, Yes. It could be the design is solid. It could be it was executed badly. It could be off the mark and it is neither of those.
We don't know what we don't know.

Quoting rheinwaldner (Reply 167):
Thanks, so we now know that a single cell died and did run away thermally. I also have to say that 8 cells is not much for such a high capacity. Why the selection of high currents instead of higher voltages?

We also must assume now, that the charger seems to have failed (we do assume, that it has a balancer).

Why must we assume that the charger failed? I don't like assuming. Remember the phrase - assumptions can make an Ass (out of) u (and) me.

Quoting WingedMigrator (Reply 178):
Sure you do: you've had one event per N flight hours. You have a rate from that, albeit with a wide confidence interval.

You do not have rate on 1 event.

Quoting seahawk (Reply 197):
I guess you mean rcair1´s post about the low energy stored in the battery or to be more exact you little Jet-A is needed for that amount of energy.

Nah - I think the posts would have been about fire response - earlier than my whimsical post about the energy content of a liter of Jet-A and a liter of Lithium Ion batteries.

Quoting tdscanuck (Reply 215):
There's a major repeated confusion going on here...the Boston ARFF extinguished the battery 40 minutes after the fire was reported to them. They did *not* fight the battery fire for 40 minutes

  

Quoting seahawk (Reply 219):
So what where the firemen doing in those 40 minutes?

Responding, making sure people were no on the aircraft, using TIC to find the source of heat, looking for extension, disconnecting the battery, removing it from the a/c, etc

Quoting rheinwaldner (Reply 230):
No, it is meaningless.

No - it is not meaningless. It does not rule out problems with cells- but it does rule out the total voltage exceeding 32 volts.

Quoting rheinwaldner (Reply 230):
So the battery burned for more than 40 minutes

Yes

Quoting rheinwaldner (Reply 230):
So you claim, that the spilled content in this case does not warrant some attention?

No. It does warrant attention and it is getting attention. It is not a conclusion.

Quoting seahawk (Reply 237):
There I do respectfully disagree. The plane at Boston showed burn marks outside the box and the fire was monitored and probably controlled by the fire fighters for the majority of the probably burn time

No -probably not. I've not see the reports, but the total active suppression time was probably a small fraction of the total burn time.
That is typically how it works on fires you are successful putting out.


BTW - Halon is not effective on Lithium fires. Halon is not a class D extinguishing agent. Some test show Halon chemically reacts with Lithium.

Topic: RE: FAA Grounds 787 Part 3
Username: HAWK21M
Posted 2013-01-21 11:33:41 and read 6920 times.

Quoting Stitch (Reply 244):
what was the purpose of that outflow valve"? Was it the one designed to ventilate smoke and gasses from the EE bay and air flow caused the electrolyte to be expelled as well? Or was that outflow valve there to vent electrolyte in the event it spilled out of the containment box?

Was this the Equipment cooling rack blower outlet?.

Topic: RE: FAA Grounds 787 Part 3
Username: abba
Posted 2013-01-21 11:34:44 and read 7013 times.

Quoting tdscanuck (Reply 215):
The problem is the rate...batteries aren't supposed to catch fire this often.



I understand. However, is two incidents statistically enough to establish "too often"? You know there are people who win mark 6 twice even if it is very rare.

Topic: RE: FAA Grounds 787 Part 3
Username: art
Posted 2013-01-21 11:53:34 and read 6861 times.

Quoting abba (Reply 252):
Quoting tdscanuck (Reply 215):
The problem is the rate...batteries aren't supposed to catch fire this often.


I understand. However, is two incidents statistically enough to establish "too often"? You know there are people who win mark 6 twice even if it is very rare.

Once knew a ship designer who worked on offshore oil rig designs for North Sea use. He told me that the structures were designed to resist a "hundred year wave". 3 "hundred year waves" occurred within 1 decade after the rigs went to work.

Topic: RE: FAA Grounds 787 Part 3
Username: rcair1
Posted 2013-01-21 11:54:54 and read 6839 times.

Quoting abba (Reply 252):
I understand. However, is two incidents statistically enough to establish "too often"? You know there are people who win mark 6 twice even if it is very rare.

I'm not a statistician - though I've used statics in production quality tests - but I don't think so. I think we can conclude 'something' happened two times. Beyond the fact that the 2 things involved the same battery model, I don't think we know much. That is not to say the are unrelated failures, but they may be, or they may be very related.

However, from a statistics standpoint - I don't think we can conclude anything.

We we MAY (big may) be able to conclude at some point is that the model used to predict failures in this battery was flawed.

[Edited 2013-01-21 12:44:17]

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-21 12:03:58 and read 6796 times.

Quoting tdscanuck (Reply 174):

That's only relevant if it's a design problem, and so far we don't know what it is. OEM testing can only pick up a manufacturing defect during testing if the defect is also present during the testing.

We're in violent agreement. I was responding to someone saying that the FAA failed to detect it and I was pointing out that it's actually the OEM's job to detect these things and report them to the FAA.

Quoting tdscanuck (Reply 174):
I disagree. After the first event, nobody had any data on whether this was very bad luck or the start of something...you don't get any rate data off a single event. All that the first event did was show that something that was believed to be possible was possible. The second event provided rate date...that's what triggered the FAA, I suspect.

I agree that grounding after the first event would have inappropriate. After the second event occurred, it was almost 24 hours until the FAA grounded the aircraft. I suspect that had more to do with time zones, but if there was "mishandling," and I'm not saying I think there was, that's the only "mishandling" I can see.

Quoting Cubsrule (Reply 205):
hat said, if the discussions in the Japanese media about these batteries coming from a single batch turn out to be accurate, there's probably an argument to be made that the grounding of the whole fleet has already gone on too long.

Until that is proved to be the cause, the grounding should continue. I very much hope that it is the cause, because then the only "fix" is to replace the affected batteries and the 787 is good to fly again. I very much hope that the issue is not in the electrical system or that there were not two separate issues that resulted in the same unacceptable failure mode.

Quoting PHX787 (Reply 223):
Many thousands of pax are stranded which makes me wonder how they are being accommodated?

Stranded? 50 airframes worldwide are out of service and people are stranded? I find that hard to believe. If the world-wide 777 fleet were grounded, I'd believe it. But not 50 788's. I think that they mean that thousands of pax are inconvenienced.

"Inconvenience" is a benign-sounding word, but when you miss a wedding (perhaps even your own), that's an "inconvenience." When you miss a family cruise that you paid $12,000 for, that's an "inconvenience." (Note: always buy trip insurance when you book a cruise). When you were delayed and your father died at the hospital before you could get there to say good-bye, that's an "inconvenience." So let's not minimize the impact. But "stranded" is what happened in Europe and the US after the Iceland volcano two summers ago.

Quoting Stitch (Reply 248):
Napoleon Bonaparte is quoted as having said "Never ascribe to malice that which is adequately explained by incompetence."

Sage words.

Topic: RE: FAA Grounds 787 Part 3
Username: dfambro
Posted 2013-01-21 12:15:19 and read 6614 times.

Quoting rcair1 (Reply 250):
Quoting WingedMigrator (Reply 178):
Sure you do: you've had one event per N flight hours. You have a rate from that, albeit with a wide confidence interval.

You do not have rate on 1 event.

WingedMigrator is correct, you can calculate confidence interval for a rate from a single event. You can calculate it for zero events.

Think of it this way, if you've been doing some action X for, say, 1000 times per year for 20 years, and you have *never* observed outcome Y (or, only observed it once), then you know something about the rate at which X leads to Y. You don't know a whole lot, but there are rates you can exclude with statistical confidence. It's just that the confidence interval is wide. With zero events, you cannot exclude that the actual rate is zero.

Topic: RE: FAA Grounds 787 Part 3
Username: airmagnac
Posted 2013-01-21 12:44:47 and read 6365 times.

Quoting rcair1 (Reply 250):
Quoting seahawk (Reply 197):
I guess you mean rcair1´s post about the low energy stored in the battery or to be more exact you little Jet-A is needed for that amount of energy.

Nah - I think the posts would have been about fire response

Yes, sorry, I meant to include the proper link in my post but I totally forgot. And I can't find the post I meant anymore.

Quoting DocLightning (Reply 255):
it was almost 24 hours until the FAA grounded the aircraft. I suspect that had more to do with time zones, but if there was "mishandling," and I'm not saying I think there was, that's the only "mishandling" I can see.

I'd expect FAA decsion-makers to get out of bed at 2am in a case like this.
The delay is more probably due to the time to
1) gather enough reliable information
2) analyse the data (compare the 2 events)
3) decide on the appropriate course of action. CM mentioned this appropriate action was determined with the use of pre-determined criteria.
4) issue the necessary orders. Also probably using prepared protocols

Items 1 and 2 can be time consuming. But you can't base decisions like this on a whim

Quoting DocLightning (Reply 255):
Quoting Cubsrule (Reply 205):
hat said, if the discussions in the Japanese media about these batteries coming from a single batch turn out to be accurate, there's probably an argument to be made that the grounding of the whole fleet has already gone on too long.

Until that is proved to be the cause, the grounding should continue

        

Topic: RE: FAA Grounds 787 Part 3
Username: seahawk
Posted 2013-01-21 12:46:23 and read 6373 times.

Quoting Kaiarahi (Reply 240):
What other batteries are in the aft bay?

Those where the damaged one is missing : http://seattletimes.com/ABPub/2013/01/08/2020087640.jpg

Quoting Stitch (Reply 244):

Yes it did. And it leaked out of the aircraft via an outflow valve, not by burning/corroding itself through the floor of the EE bay and then the fuselage like the blood of the creatures in the fictional Alien universe. As such, I believe the question to ask is "what was the purpose of that outflow valve"? Was it the one designed to ventilate smoke and gasses from the EE bay and air flow caused the electrolyte to be expelled as well? Or was that outflow valve there to vent electrolyte in the event it spilled out of the containment box?

Flammable liquid inside a bay full of electronics is not a good idea, well unless it if intentionally fed to the outflow valve. We should know this soon.

Quoting rcair1 (Reply 250):
No -probably not. I've not see the reports, but the total active suppression time was probably a small fraction of the total burn time.
That is typically how it works on fires you are successful putting out.


BTW - Halon is not effective on Lithium fires. Halon is not a class D extinguishing agent. Some test show Halon chemically reacts with Lithium.

I know. But it was monitored and I am sure they made certain that the fire could not and did not spread. Using class D foam (you call it Artic Fire in NA don´t you?) or other Class D agents was not needed. However I am not aware of any Class D fire fighting system installed in the 787. That is what worries me, if it burns the containment must work. If it works is something I can not judge, but that is the first thing I would ask Boeing to prove.

Topic: RE: FAA Grounds 787 Part 3
Username: rcair1
Posted 2013-01-21 12:48:27 and read 6338 times.

Quoting nm2582 (Reply 212):
In RC, we have available what we call "LiPo sacks". Essentially, we acknowledge and accept that even under the best circumstances, sometimes "bad things happen" and our batteries will fail. So, we charge them in the LiPo sack. It is an enclosure that is solely designed to keep the flames "smothered" and "contained" inside the sack, while still allowing all the smoke and pressure to be vented (there is no attempt made to even try and control this). It's to keep our equipment, homes, etc. from burning down.

It's entirely possible that Boeing could adapt this technology.

I think this is essentially what the containment system in the 787 is intended to do. They probably do more than this - they probably do try to 'control' venting - by venting in a coordinated way that does not depend on where you put the sack.

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-21 12:51:31 and read 6313 times.

Quoting airmagnac (Reply 257):
I'd expect FAA decsion-makers to get out of bed at 2am in a case like this.

Frankly, I'm not sure I would. I want them making a calm and rational decision. Believe me, as a physician I've made plenty of important (life-and-death) decisions at 2AM. It's really not a good time of day to be making such decisions.

Topic: RE: FAA Grounds 787 Part 3
Username: JoeCanuck
Posted 2013-01-21 13:06:49 and read 6143 times.

Quoting rcair1 (Reply 250):
I agree with you - but I would point out that in my career of responding to car crashes, I've seen a dramatic improvement from terms of survivablity and injury rate.

My point was more about how safety isn't an absolute, not that safety improvements shouldn't continue. I've read reports where the addition of so many safety mechanisms in cars has led to a sense of invulnerability in some, where they feel they can drive more recklessly, since they won't get hurt or killed.

Survivability has improved significantly more quickly than the accident rate...we're safer, but not smarter.

Topic: RE: FAA Grounds 787 Part 3
Username: Cubsrule
Posted 2013-01-21 13:07:55 and read 6149 times.

Quoting DocLightning (Reply 255):
Until that is proved to be the cause, the grounding should continue.

I don't think you meant this . . . did you mean that until a cause is found, the grounding should continue? I'd agree with that statement. It's difficult to know how frequently battery problems will happen until the cause can be identified, though I guess I could imagine a situation with a handful of potential causes of similar potential frequencies where a sole cause did not need to be determined. The issue isn't so much that these batteries are failing as that they are failing much more frequently than envisioned. The containment structure is there because everyone acknowledged that they would fail from time to time.

Topic: RE: FAA Grounds 787 Part 3
Username: abba
Posted 2013-01-21 13:14:47 and read 6061 times.

Quoting rcair1 (Reply 254):
We we MAY (big may) be able to conclude at some point is that the model used to predict failures in this battery was flawed


I do not think that this it is big MAY - rather it is a clear no.

Still I do not understand why - given the fact that batteries from time to time break down in a way that we have just seen (lets for arguments sake say that it statistically will happen once or twice each decade (then it could possibly happen twice in a month)) and the containment system worked as designed and the chain of events were as predicted - the FAA then felt the need to ground the entire fleet of 787s?

Grounding is a rather drastic measure in particular if what has happened could just be random unluck due to the way statistics works. If everything worked as predicted and designed then the FAA should rather be happy having an in operation proof of the assumptions and design rather than grounding the fleet. Or?

[Edited 2013-01-21 13:15:28]

[Edited 2013-01-21 13:16:30]

Topic: RE: FAA Grounds 787 Part 3
Username: CM
Posted 2013-01-21 13:33:20 and read 5944 times.

Quoting seahawk (Reply 258):
Those where the damaged one is missing

There are no batteries in the photo you have linked. The only battery which ever would appear in this photo is the one which is missing. There are no other batteries in the aft equipment bay.

Topic: RE: FAA Grounds 787 Part 3
Username: DocLightning
Posted 2013-01-21 13:40:13 and read 5849 times.

Quoting Cubsrule (Reply 262):
I don't think you meant this . . . did you mean that until a cause is found, the grounding should continue? I'd agree with that statement.

No no. The only acceptable cause is the one I want it to be.  

Yes, your wording is better than mine.

Quoting abba (Reply 263):
Still I do not understand why - given the fact that batteries from time to time break down in a way that we have just seen (lets for arguments sake say that it statistically will happen once or twice each decade (then it could possibly happen twice in a month)) and the containment system worked as designed and the chain of events were as predicted - the FAA then felt the need to ground the entire fleet of 787s?

Because that containment system shouldn't have HAD to "work as designed" even once, much less twice in three days. Airline safety is built on the idea of containing any incident inside layers and layers of safeguard. The battery shouldn't have caught on fire in the first place. It should be an exceedingly rare event even if it is fully contained.

If two turbofans of the same brand-new type had two contained fan failures in three days without obvious cause, would you say that they should be allowed to continue flying just because the failure was contained? No. Next time the containment might fail. The whole point of containment is that it's there in case, but we hope that it never has to "do its job."

Topic: RE: FAA Grounds 787 Part 3
Username: rcair1
Posted 2013-01-21 14:01:08 and read 5619 times.

Quoting seahawk (Reply 258):
know. But it was monitored and I am sure they made certain that the fire could not and did not spread.

Without seeing the actual incident report from BFD/MFD I don't think you can conclude these items. (and I have not seen it).

From a fire fighting perspective - the first focus will be safety of people (both public and responders) and exposures.

I can tell you from experience that we rarely take the approach of "monitoring" - except when the fire is:
1- Clearly beyond your ability to extinguish.
2- Situated where you cannot safely intervene.
3- Something you want to burn up.

Some examples - fully involved or mostly involved structure in a wildland fire setting (urban interface). With the kind of resources you typically have on scene, you will not be successful in efforts to extinguish the structure fire - so you focus on exposures. Keep the fire from spreading. From a practical standpoint, water (or foam or CAFS) being put on a fire represents BTU's being absorbed. If the fire is putting out more BTU's than your ability to absorb - then you will loose, you will run out of water, and the structure will continue to burn. You now have a working fire- but no water. Of course, it is rarely quite this black and white.

On the other hand - if you have 'close to' the resources needed to put that fire out - you move very aggressively - and you get backup on the way. There is no point in 'preserving water' if you are going to try to extinguish the structure fire - you go full out.

During in the High Park fire - once it became obvious the fire could not be controlled, crews shifted to other roles, evacuation and structure (exposure) protection. Since you cannot keep the fire away from people - you move people away from the fire (evacuation). You can't stop the fire from coming at a house, so you try to 'steer' the fire around the house (structure protection).

Moving to the 2nd item - Both these are modulated by safety of fire fighters. There are times when crews will be assigned to structure protection and have to disconnect hoses and run - because it becomes too dangerous to stay. During the High Park fire - this happened multiple times. BTW - sometimes our most effective structure protection technique was burn out - burning the fuel (for a distance) between the house and the oncoming. This is not a 'back fire' in the sense of controlling the fire - but a structure protection effort in the sense of causing the fire to not burn up to the house (no fuel).

Almost never will we "monitor" when we can act.
Fern Lake fire in Estes Park this summer was an example of this (monitoring). That fire started in RMNP in a remote area - no major threat to home/communities. Since fire is a natural part of the environment, they chose to let it burn. Later in the fall, when the fire grew and threatened communities - they initiated active efforts.

So - in Boston, while I'm sure there was a period of "monitoring" and certainly there was active overwatch/safety going on during investigation - I pretty confident the fire crews acted positively as quickly as they could.

I'm sure the actions of the BFD/MFD were informed by:
- Scene safety - first thing you do - is it safe to be there.
- Rescue - are there people that you need to save
- Locate the fire - where is the source?
- Extinguish - can you get to it safely and can you put it out.
- Overhual - looking for hidden fire .
- Salvage - save stuff.

Some of these steps can be going on concurrently.

In the HIgh Park case above - certainly there were control efforts going on while others were doing evacuation and structure protection. Frankly, however, control efforts were small compared to the other two for the first several days. There was no controlling the fire.

As I mentioned in an earlier posts - it would take a lot of 'chutzpah' for the firefighters on scene in Boston to say 'the containment system is working - let it burn out'. Nah - that's not what fire fighters do - we put out fires....

Quoting seahawk (Reply 258):
Using class D foam (you call it Artic Fire in NA don´t you?) or other Class D agents was not needed.

I believe they did use a Class D extinguisher once they had removed the battery from the a/c. I don't think they did it in the bay. If they suspected a Li fire in the bay - it would be very dangerous to use non-class D extinguishing agent - many of these will cause dramatic expansion of the fire.

Topic: RE: FAA Grounds 787 Part 3
Username: abba
Posted 2013-01-21 14:09:17 and read 5544 times.

Quoting DocLightning (Reply 265):
It should be an exceedingly rare event even if it is fully contained.



OK - If I understand you correctly, batteries are supposed to almost never break down!? And the fact that they did - and not only once (one swallow dosn't make a summer as Aristotle said) but twice - is the problem. That would be a problem only of it is supposed to be almost never (otherwise neither do two).

Topic: RE: FAA Grounds 787 Part 3
Username: iowaman
Posted 2013-01-21 14:36:05 and read 5331 times.

As this thread is getting quite lengthy please continue the discussion here:

FAA Grounds 787 Part 4 (by iowaman Jan 21 2013 in Civil Aviation)


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