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Francoflier
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 12:21 pm

Quoting sankaps (Reply 149):
Hopefully, despite their denials, this a really a short-term band-aid and they are actively working on the actual root cause identification and elimination.

They very likely are.

The problem is that there probably isn't enough data available to them to work on that. Restarting operations would help.
It begs the question, raised by Aesma above, as to why Boeing wasn't allowed to extensively fly the prototypes during this time to try and find more about the problem.
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servantleader
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 1:49 pm

Since the fix is a containment and venting of a battery failure event wouldn't it follow that uneventful test flights are of little use? And if so would Boeing be required to induce an in-flight failure to see if the containment and venting system works?
 
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Stitch
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 2:02 pm

Boeing cannot be as cavalier about this as some folks are accusing them of. Even if Boeing's solution completely removes safety as an issue, it does not remove economics as an issue and you can be sure economics weighs about as heavily with airlines as safety does. And by economics I mean restriction to ETOPS-180 (due to a fault tree that assumes the APU won't be available due to a battery failure) and the costs involved in replacing failed batteries.

Also, the NTSB and JTSB are working on the root causes of the two incidents. Once they are found, you can be 100% sure that additional Airworthiness Directives will be made to address those root causes that Boeing will need to integrate.

[Edited 2013-03-13 07:05:28]
 
hivue
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 2:16 pm

Quoting ServantLeader (Reply 151):
Since the fix is a containment and venting of a battery failure event wouldn't it follow that uneventful test flights are of little use?

Boeing has proposed new battery certification criteria to the FAA and the FAA has accepted those criteria. Boeing now will flight test the modified battery system to see if it meets the approved criteria. In this situation an "eventful" flight test program likely is the last thing Boeing wants to see.

I doubt if Boeing will purposely incenerate a battery in flight to see if the containment works. They probably can test that in a more benign, controlled manner.

[Edited 2013-03-13 07:19:15]
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phxa340
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 3:08 pm

Commercial flights to start back up in 3-4 weeks according to yahoo.

Http://www.fool.com/investing/genera...ng-investors-can-look-skyward.aspx
 
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 3:14 pm

They could put a machine emitting a liquid similar to what happened during the incidents, but benign, instead of the battery, along with a smoke generator, to test the containment in flight without danger. Or not, after all they claim that the current design isn't dangerous !

As for the battery we already know that for the original one testing included damaging a cell with nails, and that didn't cause a runaway, so they would have had to find another way.
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hivue
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 3:43 pm

Quoting Aesma (Reply 155):
As for the battery we already know that for the original one testing included damaging a cell with nails, and that didn't cause a runaway, so they would have had to find another way.

Yes, it would be interesting to know the details of the new cerification plan and how it differs from the original battery cerification criteria. The Boeing press release says:

"The certification plan calls for a series of tests that show how the improved battery system will perform in normal and abnormal conditions. The test plans were written based on the FAA's standards as well as applicable guidelines published by the Radio Technical Commission on Aeronautics (RTCA), an advisory committee that provides recommendations on ways to meet regulatory requirements. The RTCA guidelines were not available when the original 787 battery certification plan was developed."

[Edited 2013-03-13 09:40:44]
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 3:45 pm

Quoting phxa340 (Reply 154):
Commercial flights to start back up in 3-4 weeks according to yahoo.

Super 'find,' phxa340, thanks.

I'd put it at more like six weeks, given that the Europe lot will 'mobilise' whole divisions of lawyers. But, unless the coming programme of test flights reveal further problems, I'd expect that 787s will be flying in service again by early May.
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art
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 4:17 pm

Quoting phxa340 (Reply 154):
Commercial flights to start back up in 3-4 weeks according to yahoo.

I don't see how it can be done so quickly unless batteries of the revised design are already being manufactured / will be manufactured before testing is successfully concluded. Same for the containers.
 
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 4:30 pm

Compared to the costs of the grounding, having to throw away a few containment boxes (in the worst case) hardly matters.

It will be good to see the 787 flying again, as more flights will mean more data on the batteries. I am eagerly waiting to see if the return to flight will be under limitations or if they are going to go back unrestricted.
 
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 5:00 pm

Quoting ServantLeader (Reply 151):
Since the fix is a containment and venting of a battery failure event wouldn't it follow that uneventful test flights are of little use?

According to the FAA press release:

The battery system improvements include a redesign of the internal battery components to minimize initiation of a short circuit within the battery, better insulation of the cells and the addition of a new containment and venting system.
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 6:45 pm

Now that we have some actual news, why did this thread become so quiet?
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TheRedBaron
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 7:03 pm

Quoting BEG2IAH (Reply 161):

Sit and wait.... for the smoke..or not ( and I am not talking about the vatican tough)

on a serious tone.

I think that after all this grounding and its consequences most of us are waiting to see the final FIX, the repairs and the havoc it must have in future deliveries. This program is really a headache, I hope this is the medicine to put all the delays and problems in the past...
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servantleader
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 7:08 pm

Quoting BEG2IAH (Reply 161):
Now that we have some actual news, why did this thread become so quiet?

FAA approval of Boeing's proposed fix was widely anticipated and therefore wasn't really new news, and is only a baby step to resuming revenue service. The ball is back in Beoing's court now to prove that the fix will perform as advertised -- that's where the new news will be.
 
CaptainKramer
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 7:55 pm

Quoting seahawk reply 159.

Regardless of whether flights are restricted or not, I'm sure every Captain and Co-pilot of a B787 will keenly study the alternate airports available along the route during preflight briefing and during the flight itself, even more so than before.

[Edited 2013-03-13 12:58:12]
 
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 8:21 pm

Quoting Aesma (Reply 155):
They could put a machine emitting a liquid similar to what happened during the incidents, but benign, instead of the battery, along with a smoke generator, to test the containment in flight without danger. Or not, after all they claim that the current design isn't dangerous !

As for the battery we already know that for the original one testing included damaging a cell with nails, and that didn't cause a runaway, so they would have had to find another way.

Or, just intentionally short circuit a cell in a ground mockup of the E&E bay   That should show worst-case performance (i.e. no pressure differential to help ventilate the compartment!).
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RE: FAA Grounds B787: Part 13

Wed Mar 13, 2013 8:26 pm

Quoting art (Reply 158):
I don't see how it can be done so quickly unless batteries of the revised design are already being manufactured / will be manufactured before testing is successfully concluded. Same for the containers.

While I share some of your scepticism, I'd like to think that Boeing has already started many of the actions proposed to the FAA. In fact some of them might already be ready for operational testing.

This article suggests for instance that the improved battery boxes had started mass manufacturing several weeks ago:

Quoting 22 Feb 2013:
And, Boeing is already making 100 of 200 ordered battery containment boxes to allow the lithium ion batteries to safely burn up under the cockpit or rear passenger cabin in the event of any more failures like those caused the grounding of the world’s 50 strong 787 Dreamliner fleet in January
http://blogs.crikey.com.au/planetalk...n-dome-boxes/?wpmp_switcher=mobile

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RE: FAA Grounds B787: Part 13

Thu Mar 14, 2013 11:32 pm

My understanding is that testing (cert requirements) have already begun, and should be complete next week. Once the testing is complete, Boeing service bulletins will be sent to the FAA for approval (which modifies the airplanes). One SB will replace the battery (and case) and another will install the overboard exhaust system. Other modifications (not FAA mandated) will also be released for installation at the same time.

Cheers
 
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RE: FAA Grounds B787: Part 13

Thu Mar 14, 2013 11:38 pm

Quoting PW100 (Reply 166):
While I share some of your scepticism, I'd like to think that Boeing has already started many of the actions proposed to the FAA. In fact some of them might already be ready for operational testing.

In addition, has it been released what Boeing actually did / tested on the test flights that were conducted a couple weeks ago?
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 12:35 am

Quoting KELPkid (Reply 165):
Or, just intentionally short circuit a cell in a ground mockup of the E&E bay   That should show worst-case performance (i.e. no pressure differential to help ventilate the compartment!).

Think it would be easier to just use one of the frames they wrote off if they are worried. Just light off a battery in each end of #3 and call it good. Also be a good way to test your writeup of the install procedures for the modification since mistakes can be ironed out on a frame that isn't going to a customer.
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 2:16 am

Quoting ServantLeader (Reply 151):
Since the fix is a containment and venting of a battery failure event wouldn't it follow that uneventful test flights are of little use?
Quoting par13del (Reply 168):
In addition, has it been released what Boeing actually did / tested on the test flights that were conducted a couple weeks ago?

I'll take an educated guess that the purpose of the test flights was a monitoring of depletion and recharge voltages ..looking for stray output and input that might have spiked .. something that could be theoretically checked by computer or in the lab, but having much more convincing results in the flight envelope.

Interesting in Japanese pitch, the main battery is only used from breaking when under tow (engines off) whereas some posts above seemed to imply it was used for all breaking. the pitch makes no reference to the APU battery being required for the APU controller where I believe it is only required when other electrical sources are not available (engines)
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 4:35 am

Boing now says no fire possible with new changes. Has more details on the design changes.

Boeing: ‘no fire is possible’ with 787 battery fix

Quote:
...
...
That box “eliminates the possibility of fire,” said Sinnett.

The first layer of improvements is inside the GS Yuasa plant that manufactures the batteries in Japan. Boeing and GS Yuasa have tightened quality controls and added new tests on the batteries that come off the line.

A series of design changes have been made inside the battery, too. These include an electrical insulator wrapped around each of the eight battery cells, to electrically isolate cells from each other and from the battery case, even in the event of one cell’s failure.

Electrical and thermal insulation installed above, below and between the cells will help keep the heat of the cells from affecting each other.

Wire sleeving and the wiring inside the battery will be upgraded to be more resistant to heat and chafing and new self-locking fasteners will attach the metallic bars that connect the eight cells of the battery.

Small holes at the bottom of the battery case that contains the battery cells and the battery management unit will allow moisture to drain away from the battery.

In addition, Boeing is adjusting the battery charger to narrow the acceptable level of charge for the battery. It will both lower the highest charge allowed and raise the lower level allowed for discharge.

The final level of protection is the steel box enclosing everything.

...
“This enclosure keeps us from ever having a fire to begin with,” he said.
...
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 8:22 am

Anybody has a clue of how the 'overboard exhaust system' will work?

There will be a new hole in the fuselage somewhere, but will it be permanently opened, creating a constant outboard flow, or will it have a 'dump' valve of some sort?
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KarelXWB
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 9:14 am

Boeing's Sinnett says no ETOPS limitations when 787 fleet comes back after the grounding is lifted.

http://twitter.com/jonostrower/status/312390118096904193
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 11:01 am

Randy kindly explains quite thoroughly the "multiple layers of improvements":

http://www.boeingblogs.com/randy/arc...aring_our_solution_1.html#comments
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NAV20
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 1:35 pm

Thanks for the link, BlueShamu330s. Most interesting, and on the face of it 'convincing.' There's one paragraph that struck me as particularly relevant:-

"We’ve also decided to narrow the acceptable level of charge for the battery, both by lowering the highest charge allowed and raising the lower level allowed for discharge. Two pieces of equipment in the battery system - the battery monitoring unit and the charger— are being redesigned to the narrower definition. The battery charger will also be adapted to soften the charging cycle to put less stress on the battery during charging."

I have to confess that I'm pretty ignorant about electricity!   But it HAS often struck me during these discussions that, besides the two incidents that caused the grounding, there've been frequent references to batteries being replaced because of charging problems; or, rather, because an unusually high proportion of them had to be replaced because they couldn't be recharged 'in situ.' It seems at least probable to me that the charging process needs, as Randy puts it, to be 'softened.'

Let's hope that that's the basic problem; and that Boeing's proposals will work, and be accepted by the authorities, and that the 787 will 'return to service' in the relatively near future.

[Edited 2013-03-15 06:41:36]
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hivue
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 2:19 pm

Quoting kanban (Reply 170):
Interesting in Japanese pitch, the main battery is only used from breaking when under tow (engines off) whereas some posts above seemed to imply it was used for all breaking

I think previous posts actually implied that it also is necessary for braking in the rare instance when engine and APU sources of electrical power are unavailable (RAT loses effctiveness after touch down).

Quoting kanban (Reply 170):
the pitch makes no reference to the APU battery being required for the APU controller where I believe it is only required when other electrical sources are not available

See footnote 6 on page 1 of the NTSB interim report: "The APU battery provides power to start an APU during ground and flight operations. The APU controller (discussed in section 1.6.5) monitors the parameters that are needed to operate the APU. The APU controller is powered by the APU battery bus, which receives its power from the APU battery. If the APU battery fails, then the APU battery bus will no longer receive power, and the APU will shut down."

In the "pitch" I don't recall anyone refering to this issue at all.
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Stitch
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 4:19 pm

Quoting NAV20 (Reply 175):
But it HAS often struck me during these discussions that, besides the two incidents that caused the grounding, there've been frequent references to batteries being replaced because of charging problems; or, rather, because an unusually high proportion of them had to be replaced because they couldn't be recharged 'in situ.' It seems at least probable to me that the charging process needs, as Randy puts it, to be 'softened.'

Deep-discharging a Li-Ion battery can evidently increase the chances of a thermal runway, so Boeing likely places a limit on how far you can discharge it to prevent the battery from approaching a condition where it could enter thermal runaway.

A deep recharge can also evidently increase the chance of a thermal runaway, so if the battery is run down that deep, it might be a safety measure to have it recharged off the plane. It's also possible that the BCS's existing charging limits (to ensue the battery cannot be too rapidly charged and risk degradation or thermal runaway) are such that it could take too long of a time to re-charge the battery from that discharged state on-board the plane to whatever level is necessary for safety-tree reasons.

[Edited 2013-03-15 09:21:20]
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 4:34 pm

Quoting blrsea (Reply 171):
Boing now says no fire possible with new changes.

Hearing such an absolute statement does anything but make me feel better. To me, it only makes a potential future incident all the more damning.

-Dave
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Stitch
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 4:42 pm

Quoting PlanesNTrains (Reply 178):
Hearing such an absolute statement does anything but make me feel better. To me, it only makes a potential future incident all the more damning.

Considering the requirement is that for every flight hour there is a one-in-a-billion chance of a fire, that pretty much means you can't have a fire so that is the goal Boeing has to aim for.
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 4:52 pm

Quoting PlanesNTrains (Reply 178):
Hearing such an absolute statement does anything but make me feel better. To me, it only makes a potential future incident all the more damning.

I agree. Much better to state the the chances are extremely remote.

Speaking in absolutes is not a good habit, I never do that!  
 
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Revelation
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 5:05 pm

Quoting blrsea (Reply 171):
That box %u201Celiminates the possibility of fire,%u201D said Sinnett.

Hmmm...

Quoting PlanesNTrains (Reply 178):
Hearing such an absolute statement does anything but make me feel better. To me, it only makes a potential future incident all the more damning.

Agreed.

We read in:

Quoting BlueShamu330s (Reply 174):
Randy kindly explains quite thoroughly the "multiple layers of improvements":
http://www.boeingblogs.com/randy/arc...ments

that:

Quote:

Through another test, the team demonstrated that fire cannot occur within the new enclosure. Its design eliminates oxygen, making the containment unit self-inerting. Inerting is a step above fire detection and extinguishing as it prevents a fire from ever occurring.

And:

Quote:

During engineering testing, which occurs prior to certification testing, the team demonstrated that the new housing could safely contain a battery failure that included the failure of all eight cells within the battery. The �ultimate� load is the equivalent of 1.5 times the maximum force ever expected to be encountered during a battery failure. The housing easily withstood this pressure and did not fail until the pressure was more than three times the ultimate load.

So it seems the approach is one of belt and suspenders.

Even with this additional description I still don't see how fire is impossible given the fact that the LiIon battery chemicals make their own oxygen, but such tech points are discouraged in this thread, so I'll take them elsewhere.

I agree it's dangerous for high level 787 execs (chief engineer, cheif marketer) to make such absolute statements. They've had incidents occurring at a rate that they didn't predict correctly whose root cause they've been unable to determine, and now making such absolute statements will of course draw notice.

Maybe they are stuck between a rock and a hard place: the company will push them out the door if they don't promote this line of thinking, and of course the company will push them out the door if the line of thinking is proven incorrect?

It all makes me think of the Big Lie theory because such an absolute statement is needed to plant the big lie. Of course I have no way of knowing if this is a lie, I'm saying that if it is a lie such absolute statements are the best way to make it stick.
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Stitch
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 5:11 pm

Li-Ion batteries do not generate their own oxygen, especially when under thermal runaway.

Independent testing have identified that no significant amount of oxygen is found in cell vent gases. Any internal production of oxygen will affect cell internal reactivity, cell internal temperature, and cell case temperature, but plays no measurable role in the flammability of vent gases.

Boeing themselves noted they could not ignite the electrolyte vapor without adding a supply of external oxygen and even then, the vapor self-extinguised within 200 milliseconds (once it consumed that supply of external oxygen).

So Boeing's new design seems to knock one side out of the Fire Triangle - and a fire needs all three sides to happen.

[Edited 2013-03-15 10:21:45]
 
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 5:29 pm

Quoting Stitch (Reply 182):
Li-Ion batteries do not generate their own oxygen, especially when under thermal runaway.

Independent testing have identified that no significant amount of oxygen is found in cell vent gases.

Thanks for the correction.
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PlanesNTrains
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 5:55 pm

Quoting Stitch (Reply 179):
Considering the requirement is that for every flight hour there is a one-in-a-billion chance of a fire, that pretty much means you can't have a fire so that is the goal Boeing has to aim for.

Oh, I understand. It just makes me apprehensive when it comes to this program. Not because I believe they are lying, but because it just creates more drama here on a.net.

-Dave
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sankaps
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 6:21 pm

Quoting PlanesNTrains (Reply 184):
Quoting Stitch (Reply 179):
Considering the requirement is that for every flight hour there is a one-in-a-billion chance of a fire, that pretty much means you can't have a fire so that is the goal Boeing has to aim for.

Oh, I understand. It just makes me apprehensive when it comes to this program. Not because I believe they are lying, but because it just creates more drama here on a.net.

Well, statisticaly that is about one battery fire every 10 years in the world's total pax aircraft fleet (using some back-of-envelope calculations). Which is a rate > 0.

Of course 787s are and will be only a small part of that fleet, but if Li-Ion batteries were to become the standard for all aircraft, this is the failure rate that would be implied.

So safer to not make absolute statements.
 
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bikerthai
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 7:25 pm

Quoting francoflier (Reply 172):
Anybody has a clue of how the 'overboard exhaust system' will work?

I understood, but probably can't explain it well enough for every one.

If you haven't already done so, check out the video and slides from the presentation linked int he Tech Ops discussion.

Quoting sankaps (Reply 185):

Well, statisticaly that is about one battery fire every 10 years

Ho Hum, 10 years from now we will look at lithium ion battery incident as ordinary as we do with turbine blade failure. Who here would say that as of now, a lithium battery failure (with the proposed design changes) would be worst than a turbine blade failure? Or even a engine surge or heaven forbid, a bird ingestion.

bt
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RE: FAA Grounds B787: Part 13

Fri Mar 15, 2013 7:36 pm

So from a philosophical stand point (for all those who did not watch the video all the way to the end), what Boeing has done is use the standard procedure for designing. They are not designing to eliminate failure of the battery or of anything on the airplane for that matter. They are designing to provide a fail safe system where in event of a failure, the plane does not go down. (Similary the TSA don't care if you hurt a passenger with your pocket knife, they know that you and your pocket knife can not bring down the airplane - unless you are Mac Gyver)

This is no different than if you get a failure of a power transformer on the airplane. A transformer failure could be spectacular but as design it would not take down the airplane.

They do not need to know why the transformer, the battery or the pitot tube (ala A330) fail. They just need to demonstrate that in event of such failure, the airplane can make it to an airport safely.

Don't get hang up on the battery, look at the system and see if its sufficient. As for the battery itself, it's a cost analysis. If more battery fail, it's going to cost Boeing lots more money, but would not bring down an airplane. (At least this Engineer seems to be satisfy with the presentation - though who cares what I think 


bt

[Edited 2013-03-15 12:39:28]

[Edited 2013-03-15 12:40:15]
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mjoelnir
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 11:27 am

Quoting Stitch (Reply 182):
Independent testing have identified that no significant amount of oxygen is found in cell vent gases. Any internal production of oxygen will affect cell internal reactivity, cell internal temperature, and cell case temperature, but plays no measurable role in the flammability of vent gases.

When you read this statement it is typical as many of the half truth statements are formulated in this battery PR spin.

Why should we find free oxygen in the vent gas?
When the oxygen is already consumed in the reactions inside the battery we would have to look for CO2 and H20 in the vent gas.
There should be neither H2O (there is no water in lithium ion batteries) nor CO2 without a chemical reaction in the cells, and it calls for a semantic expert if you call it fire or not.
The oxygen produced at a thermal runaway in the ion/lithium cells is not enough to burn of all the available fuel in the cell.

And it is astounding how carefully Boeing spokes people are not mentioning what the electrolyte in the battery cells is, and how careful in that connection they do not mention combination of organic solvent and salt or flammable liquid.

If one would take the PR spin completely serious one should get afraid.
But all the same what the public lawyer vetted statements are saying, one knows that Boeing is working to solve this battery problem and will solve it.
The proposed solution shows that the danger of fire and/or explosion is taken seriously.

[Edited 2013-03-16 04:34:09]
 
sankaps
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 1:05 pm

In all seriousness though, we should wait for the comprehensive tests of the proposed fixes to conclude first before we start the "told you so" comments. This testing is step 1. Impact on ETOPS etc will depend on how the tests fare, I would believe. I think most people want the 787 to fly ASAP, and no one seriously expects the program to be cancelled, though a change in battery technology was and is still viewed as a possible final outcome.
 
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lightsaber
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 5:46 pm

Quoting BlueShamu330s (Reply 174):

Randy kindly explains quite thoroughly the "multiple layers of improvements":

http://www.boeingblogs.com/randy/arc...ments

As much as that is in marketing speak, it has enough information for those of us who know risk to understand roughly the risk buydown.

Lightsaber
IM messages to mods on warnings and bans will be ignored and nasty ones will result in a ban.
 
AeroWesty
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 5:52 pm

For perspective for those who read this thread ten years from now, Boeing stock closed Friday at $86.43, up $1.81 in an otherwise down market overall (Dow off 25).
International Homo of Mystery
 
dfambro
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 7:58 pm

Question about ETOPS impact.
If the new containment basically prevents any battery problem from having catastophic consequences, then why would any ETOPS rating be at risk? The only thing that would eliminate electrical power in that instance is a dual engine out, and isn't the likelihood of that what determines ETOPS?
 
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Stitch
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 8:22 pm

Quoting dfambro (Reply 192):
If the new containment basically prevents any battery problem from having catastophic consequences, then why would any ETOPS rating be at risk?

If the APU battery is inoperative, the 787 is limited to ETOPS-180. Also, it appears the APU battery is required to operate the APU - even if the APU is started, it appears to need the battery to keep running. With an inoperative APU, the 787 is limited to ETOPS-180.

So if APU batteries continue to fail, even if their failure does not impact the safety of the airframe in any way, regulatory agencies would not be able to certify the 787 for ETOPS-240 or ETOPS-330 unless they changed the regulations to allow the plane to fly farther with an inoperative APU battery or APU (once the battery failed and shut down the APU).
 
BlueShamu330s
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 9:42 pm

Hold on, didn't Mr Smisek reassure the world that ETOPS would not be affected ???

Rgds
Flying around India
 
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Stitch
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RE: FAA Grounds B787: Part 13

Sat Mar 16, 2013 9:52 pm

Quoting BlueShamu330s (Reply 194):
Hold on, didn't Mr Smisek reassure the world that ETOPS would not be affected?

As I believe the current ETOPS limit for the 787-8 is ETOPS-180, it would indeed not be affected.

(The FAA and EASA Type Certificates show it as ETOPS-180. And Japan just recently increased it to ETOPS-180.)
 
NAV20
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RE: FAA Grounds B787: Part 13

Sun Mar 17, 2013 12:27 am

Boeing are now saying that testing will be completed within two weeks - apparently most of it is being done on the ground, they only envisage one actual test flight:-

"Boeing said Friday that it expects to finish testing its battery fix for the 787 within two weeks. Then it will be up to the Federal Aviation Administration to decide when the planes fly again.

"Boeing is testing several changes to the plane's lithium-ion battery aimed at preventing overheating and fire -- conditions that led to the global fleet of 787s being grounded for the past two months.

"Ron Hinderberger, Boeing's vice president for engineering on the 787, said Friday that there will be one flight test. Most tests will be done on the ground, and all should all be done in one to two weeks. "We would like to complete those tests as soon as possible," he said."


http://www.cleveland.com/business/in...oeing_official_resuming_787_f.html

After that the ball will be back in the FAA's court.
"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
 
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KarelXWB
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RE: FAA Grounds B787: Part 13

Mon Mar 18, 2013 10:36 am

From the LOT Facebook page:

Quote:
The return of the Dreamliners is nigh!

Schedule for 787 repairs was created at Friday's meeting with Boeing representatives. Both our planes have a chance to come back to full functionality as ones of the first among all of the previously grounded aircrafts. This means that the return of the Dreamliners on Polish sky during Summer Season becomes more likely.

Modification of the machines will be carried out in cooperation with a team of Boeing's engineers. Test phase is to be joined by European Aviation Safety Agency, what should speed up the process.

Keep your fingers crossed for the smooth running of the repairs and wait for the next good news! Three more Dreamliners are already packing their bags and getting ready to join our fleet!
http://www.facebook.com/PllLOT

[Edited 2013-03-18 03:37:01]
What we leave behind is not as important as how we've lived.
 
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bikerthai
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RE: FAA Grounds B787: Part 13

Mon Mar 18, 2013 2:17 pm

Quoting NAV20 (Reply 196):
Boeing are now saying that testing will be completed within two weeks - apparently most of it is being done on the ground, they only envisage one actual test flight:-

For those not familiar with the testing involved. The flight testing is the last step in the whole certification process other than the paperwork. They are usually not design to flush out any issue. They are really meant to verify that all the testing that was done on the ground is verified (through the collected data) in flight. You would require much more flights if you were to use the flight test to flush out the issues.

Now, not to say that there would be no surprised that may crop up during flight testing. If issues do arise, it would just mean that the umpteenth experts that Boeing brought together are still not smart enough to build the perfect battery 

And depending on the severity of the issue they may or may not have to go back to square 1.

  

bt
Intelligent seeks knowledge. Enlightened seeks wisdom.
 
RickNRoll
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RE: FAA Grounds B787: Part 13

Tue Mar 19, 2013 12:26 pm

Quoting NAV20 (Reply 196):
Boeing are now saying that testing will be completed within two weeks - apparently most of it is being done on the ground, they only envisage one actual test flight:-

I have to question that. There was plenty of bench testing, but it didn't show up the root cause. It was actual commercial flight conditions that seemed to bring it out. I think it will be safe enough to fly with the improvements they have proposed, but the testing does seem to be too limited.

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