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FAA Approves Boeing 787 Battery System Changes  
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Posted (1 year 8 months 1 week 5 days 6 hours ago) and read 24534 times:
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Since FAA Grounds B787: Part 14 (by LipeGIG Mar 23 2013 in Civil Aviation) is approaching 300 posts, which is usually when the thread is closed and a new one opened and because the FAA will shortly lift the grounding, I figure we can start a new thread.

The FAA has approved the battery system design changes developed by Boeing for the 787. The FAA will publish next week the final directive that will allow UA to resume operations of the 787. It is expected other regulatory agencies will follow shortly to allow the 787 to resume services worldwide.


http://www.faa.gov/news/press_releases/news_story.cfm?newsId=14554

151 replies: All unread, showing first 25:
 
User currently offlineNorcal773 From United States of America, joined Feb 2007, 1451 posts, RR: 12
Reply 1, posted (1 year 8 months 1 week 5 days 6 hours ago) and read 24545 times:

About friggin' time!!


If you're going through hell, keep going
User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 2, posted (1 year 8 months 1 week 5 days 6 hours ago) and read 24510 times:

And perhaps the most important thing: the FAA decides to keep the 787 3-hour ETOPS approval.


Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlinetugger From United States of America, joined Apr 2006, 5797 posts, RR: 10
Reply 3, posted (1 year 8 months 1 week 5 days 6 hours ago) and read 24513 times:

How soon will they return to flight? How long will it take the fixes to be put in place. And can the plane fly without the fix (i.e. in order to go get the fix) or is it fix it in place then fly it?

Tugg



I don’t know that I am unafraid to be myself, but it is hard to be somebody else. -W. Shatner
User currently offlineCALTECH From Poland, joined May 2007, 2322 posts, RR: 26
Reply 4, posted (1 year 8 months 1 week 5 days 6 hours ago) and read 24441 times:

Quoting tugger (Reply 3):
How soon will they return to flight? How long will it take the fixes to be put in place. And can the plane fly without the fix (i.e. in order to go get the fix) or is it fix it in place then fly it?

Fix it then fly.



UNITED We Stand
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 5, posted (1 year 8 months 1 week 5 days 5 hours ago) and read 24395 times:
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Quoting KarelXWB (Reply 2):
And perhaps the most important thing: the FAA decides to keep the 787 3-hour ETOPS approval.

Is that confirmed?



Quoting tugger (Reply 3):
How soon will they return to flight?

As early as next week for UA, once the FAA publishes the final directive, though the planes will need to be modified before they will be allowed to fly.

Other regulatory agencies will be working on their own timelines. Ethiopia may lift it today since Ethiopian Airlines was loading 787 flight schedules for tomorrow. However, I would guess that the FAA will require foreign operators of the 787 flying them within the US to have the fix. Boeing has a team in Addis Adaba working on the planes, but I believe it will be a few weeks before they are all completed.

Japan's Transport Ministry have said they intend to allow NH and JL to resume operations "quickly", though they will require both operators to introduce new safety measures, including remote monitoring of battery data such as voltage. They also call for more frequent battery inspections, from the present rate of about once every two years.

[Edited 2013-04-19 12:19:45]

User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 6, posted (1 year 8 months 1 week 5 days 5 hours ago) and read 24394 times:

Quoting tugger (Reply 3):
How soon will they return to flight? How long will it take the fixes to be put in place. And can the plane fly without the fix (i.e. in order to go get the fix) or is it fix it in place then fly it?

It will take mechanics 4 to 5 days per airplane to install the new battery. Boeing is sending teams to their customers to assist with the replacement of the batteries.



Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 7, posted (1 year 8 months 1 week 5 days 5 hours ago) and read 24311 times:

Quoting Stitch (Reply 5):
Is that confirmed?

Dominic Gates, an aerospace reporter for the Seattle Times, confirms this on Twitter.

Quote:
FAA spokeswoman Laura Brown said the agency hasn’t changed the Dreamliner’s ETOPS (“extended operations”) certification, which means the 787 will have continued approval to fly up to three hours away from the nearest airport.



Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offline817Dreamliiner From Montserrat, joined Jul 2008, 2612 posts, RR: 2
Reply 8, posted (1 year 8 months 1 week 5 days 5 hours ago) and read 24312 times:

Quoting Stitch (Reply 5):
Is that confirmed?


It seems so. Saw a tweet from Dominic Gates which says so.



Reality be Rent. Synapse, break! Vanishment, This World!
User currently offlineAeroWesty From United States of America, joined Oct 2004, 20822 posts, RR: 62
Reply 9, posted (1 year 8 months 1 week 5 days 4 hours ago) and read 23766 times:

Long-awaited, excellent news. I wonder how many AOG teams they've assigned to do the rework. At 4-5 days per plane, that would take 3-4 weeks for 10 teams to get through all 50 planes, then there are the planes sitting at the factory which need the mod as well.


International Homo of Mystery
User currently offlineyellowtail From United States of America, joined Jun 2005, 6358 posts, RR: 2
Reply 10, posted (1 year 8 months 1 week 5 days 3 hours ago) and read 23472 times:

Quoting AeroWesty (Reply 9):

Long-awaited, excellent news. I wonder how many AOG teams they've assigned to do the rework. At 4-5 days per plane, that would take 3-4 weeks for 10 teams to get through all 50 planes, then there are the planes sitting at the factory which need the mod as well.

I would assume that Boeing has not been sitting around twiddling their fingers waiting for the FAA Approval. Presumably they had an indication that this fix woudl be approved and probably have a few aircraft done already waiting on the approval. at the very least they have a lot of prep work down already that would cut that 5 day time down to a day.



When in doubt, hold on to your altitude. No-one has ever collided with the sky.
User currently offlineDocLightning From United States of America, joined Nov 2005, 20365 posts, RR: 59
Reply 11, posted (1 year 8 months 1 week 5 days 3 hours ago) and read 23416 times:

Quoting yellowtail (Reply 10):
Presumably they had an indication that this fix woudl be approved and probably have a few aircraft done already waiting on the approval.

That would be very silly of them. It would be far more expensive to have to undo the fix if approval wound up being denied than to just wait a few more days and wait for approval.

I really hope this is the last major issue that the 787 has. If there is one more on this scale, it might be a program killer.


User currently offlinesonomaflyer From United States of America, joined Apr 2010, 1890 posts, RR: 0
Reply 12, posted (1 year 8 months 1 week 5 days 2 hours ago) and read 23196 times:
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Quoting DocLightning (Reply 11):
Quoting yellowtail (Reply 10):
Presumably they had an indication that this fix woudl be approved and probably have a few aircraft done already waiting on the approval.

That would be very silly of them. It would be far more expensive to have to undo the fix if approval wound up being denied than to just wait a few more days and wait for approval.

I really hope this is the last major issue that the 787 has. If there is one more on this scale, it might be a program killer

Boeing submitted only one fix. That fix was finalized after input from the FAA. Today's announcement is simply a public pronouncement. Boeing had a fix and tested the fix and deployed teams around the world with the parts to implement the fix.

It is likely some a/c will already be done. Expect to see aircraft on revenue flights next week with the fix in-place.

[Edited 2013-04-19 15:18:48]

User currently offlinemptpa From United States of America, joined Feb 2006, 546 posts, RR: 0
Reply 13, posted (1 year 8 months 1 week 5 days 2 hours ago) and read 23121 times:

I believe Boeing AOG teams had been a'at work' at least since last week. Seems like ET is one of them as they are trying to get the flights started in the coming days. I would also fathom a guess and say NH and JL has a few teams in place in Japan from Boeing as the first ones. So like sonomaflyer above states, I believe Boeing had this info from FAA a while back, and they have been quietly building up the changes, which makes sense.

Now hopefully, there was a team in ORD and/or IAH to get the UAL and LOT birds up and away. I believe no one can fly them out till the FAA AD is registered in the Federal Registrar, right?


User currently offlinesonomaflyer From United States of America, joined Apr 2010, 1890 posts, RR: 0
Reply 14, posted (1 year 8 months 1 week 5 days 2 hours ago) and read 23005 times:
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Quoting mptpa (Reply 13):
Now hopefully, there was a team in ORD and/or IAH to get the UAL and LOT birds up and away. I believe no one can fly them out till the FAA AD is registered in the Federal Registrar, right?

I don't see them trying to get approval from all of the countries overflown on a ferry flight for LOT (for example) to fly the a/c back to WAW to do the fix. They'll likely fix that a/c in ORD then either ferry back or do a revenue flight back from ORD with a crew deadheading out from WAW.


User currently online7BOEING7 From United States of America, joined Oct 2012, 1772 posts, RR: 16
Reply 15, posted (1 year 8 months 1 week 5 days 1 hour ago) and read 22732 times:

Quoting yellowtail (Reply 10):
Presumably they had an indication that this fix woudl be approved and probably have a few aircraft done already waiting on the approval. at the very least they have a lot of prep work down already that would cut that 5 day time down to a day.
Quoting DocLightning (Reply 11):
That would be very silly of them. It would be far more expensive to have to undo the fix if approval wound up being denied than to just wait a few more days and wait for approval.

Boeing has been communicating with the FAA daily since the grounding began. Even though the grounding was only lifted today they had a complete understanding of what modifications the FAA would require when the final paperwork comes out in the days ahead. As well as LOT ZA272 (86) that was used as the test airplane, ANA ZA512 (83) was modified and completed a FCF yesterday paving the way for a C-1 (as soon as all the i's are dotted and the t's crossed) and GUN ZA380 (34) was modified and scheduled for a B-1 yesterday but hasn't made it airborne yet.

While the AOG teams are modifying airplanes in the field there have also been teams made up of manufacturing people making those modifications at KPAE. I'm sure we'll see 2 or even 3 B-1's/FCF's a week over the next several weeks at KPAE.


User currently offlineBestWestern From Hong Kong, joined Sep 2000, 7313 posts, RR: 57
Reply 16, posted (1 year 8 months 1 week 5 days 1 hour ago) and read 22693 times:

Excellent news. I had feared that the fleet would not be up and flying before the summer peak, but now it seems that the Boeing AOG team can get the entire operation fleet up and running before the June peak.


The world is really getting smaller these days
User currently offlinecornutt From United States of America, joined Jan 2013, 338 posts, RR: 1
Reply 17, posted (1 year 8 months 1 week 5 days ago) and read 22266 times:

I wonder how many of the a/c that are still in Everett have had some work done already.

User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 18, posted (1 year 8 months 1 week 4 days 23 hours ago) and read 21773 times:

Well let the fixes and deliveries begin! And the flights too! I've been itching to see them in action again in HND


Follow me on twitter: www.twitter.com/phx787
User currently offlinedavidho1985 From Hong Kong, joined Oct 2012, 376 posts, RR: 0
Reply 19, posted (1 year 8 months 1 week 4 days 23 hours ago) and read 21560 times:

Quoting DocLightning (Reply 11):
That would be very silly of them. It would be far more expensive to have to undo the fix if approval wound up being denied than to just wait a few more days and wait for approval.

First, the chance of the modification being rejected is highly unlikely. Second, it cost both Boeing and the airlines a lot for the grounding of 787 every single day. Therefore, the risk (and the cost) of re-do the fix will outweight the cost of waiting for a few more days.


User currently offlineRobK From United Kingdom, joined Sep 2004, 3958 posts, RR: 18
Reply 20, posted (1 year 8 months 1 week 4 days 23 hours ago) and read 21507 times:

So, how long until the next one catches fire then, given that the root cause still has not been established...   

(awaits    and pun not intended)


User currently offlineYYZAMS From Canada, joined Feb 2011, 232 posts, RR: 0
Reply 21, posted (1 year 8 months 1 week 4 days 22 hours ago) and read 21396 times:

I think I will let it fly around for a year or 2 before I go out of my way to fly on a 787....just my 2 cents (oops..I mean 5 cents since we no longer have the penny)

User currently offlineastuteman From United Kingdom, joined Jan 2005, 10253 posts, RR: 97
Reply 22, posted (1 year 8 months 1 week 4 days 22 hours ago) and read 21332 times:
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Quoting Stitch (Thread starter):
The FAA has approved the battery system design changes developed by Boeing for the 787
Quoting KarelXWB (Reply 2):
And perhaps the most important thing: the FAA decides to keep the 787 3-hour ETOPS approval.

Excellent news on both counts. Well done to all who have been involved in getting the 787 flying again   

Rgds


User currently offlineAircellist From Canada, joined Oct 2004, 1735 posts, RR: 8
Reply 23, posted (1 year 8 months 1 week 4 days 22 hours ago) and read 21194 times:

Quoting astuteman (Reply 22):
Well done to all who have been involved in getting the 787 flying again

Yes, and let's hope we'll regain two of our valued contributors… who have precisely been involved in that work.


User currently offlineikramerica From United States of America, joined May 2005, 21589 posts, RR: 59
Reply 24, posted (1 year 8 months 1 week 4 days 21 hours ago) and read 20666 times:

Quoting DocLightning (Reply 11):
That would be very silly of them. It would be far more expensive to have to undo the fix if approval wound up being denied than to just wait a few more days and wait for approval.

True, but this is fixing something that can't be proved to be fixed or broken to begin with, so the approved fix is mostly a feel good move to make everyone think that something has been done to turn a "dangerous" plane into a "safe" plane.



Of all the things to worry about... the Wookie has no pants.
User currently offlinesweair From Sweden, joined Nov 2011, 1833 posts, RR: 0
Reply 25, posted (1 year 8 months 1 week 4 days 18 hours ago) and read 20181 times:

50 in service+ about 35 waiting for the fix and pre delivery process, this year could still be a great 787 delivery year, the first 787-9 is soon loaded into the FAL, a few more frames in front of it.

User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 26, posted (1 year 8 months 1 week 4 days 14 hours ago) and read 19148 times:

Quoting yellowtail (Reply 10):
I would assume that Boeing has not been sitting around twiddling their fingers waiting for the FAA Approval. Presumably they had an indication that this fix woudl be approved and probably have a few aircraft done already waiting on the approval.

It seems like this is not the case:

Quote:
Despite the uncertainties of when a battery kit will be delivered to each aircraft and when crews will begin working, it’s an easy guess that flights will not resume for at least a few weeks.

The repair kits could not be pre-positioned with the airlines in anticipation of the FAA’s approval because federal law requires them to remain with the manufacturer until the agency acts. Boeing has sent them to its global spares repositories but they still need to be physically shipped to the airlines.



Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlineairmagnac From Germany, joined Apr 2012, 321 posts, RR: 52
Reply 27, posted (1 year 8 months 1 week 4 days 14 hours ago) and read 19409 times:



Quoting astuteman (Reply 22):
Well done to all who have been involved in getting the 787 flying again

 checkmark   checkmark   checkmark   thumbsup 



Quoting Aircellist (Reply 23):
let's hope we'll regain two of our valued contributors… who have precisely been involved in that work.

I certainly hope so...but one of the two profiles is not active anymore, and the profile info of the other one indicates that he seems to have been seduced by the dark side   and is doing an MBA in Boston

Quoting ikramerica (Reply 24):
, but this is fixing something that can't be proved to be fixed or broken to begin with, so the approved fix is mostly a feel good move to make everyone think that something has been done to turn a "dangerous" plane into a "safe" plane.

  

Engineers look at the entire causal chain around the main visible event (in this case, the battery overheat) and work on either the causes (to prevent the event) or the consequences (mitigate the effect of the event)

UPSTREAM of the event, it is indeed still not known for certain what caused the problem. But even though no specific fix can be carried out on the one specific cause, I understand some general modifications were made to cater for a wide range of possible causes.
DOWNSTREAM of the event, the fixes Boeing has implemented have been widely reported (casing, venting etc...), with the objective of making sure that if the batteries have similar problems, it cannot lead to any foreseeable catastrophic damage.

This is a technically justified fix, that turns a "maybe-perhaps-possibly-under certain circumstances-dangerous" plane into an "as safe as we can make it" plane...but only if the fix is properly designed and executed.

[Edited 2013-04-20 04:15:03]


One "oh shit" can erase a thousand "attaboys".
User currently offlineRobK From United Kingdom, joined Sep 2004, 3958 posts, RR: 18
Reply 28, posted (1 year 8 months 1 week 4 days 11 hours ago) and read 18451 times:

Quoting airmagnac (Reply 27):
DOWNSTREAM of the event, the fixes Boeing has implemented have been widely reported (casing, venting etc...), with the objective of making sure that if the batteries have similar problems, it cannot lead to any foreseeable catastrophic damage.

Well that's very reassuring for me as pax. Being over the middle of the Pacific at 39k and 3 hours from the nearest suitable airfield whilst having a raging inferno underway in the battery compartment would not bother me in the slightest. Nope, I'd be completely fine with that as the FAA said so.


User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 29, posted (1 year 8 months 1 week 4 days 11 hours ago) and read 18358 times:

The containment box should prevent any fire from spreading. The box is also sealed off, no air can go in, so a fire should extinguish itself (and there is a venting system too).

No need to fear an inferno  

[Edited 2013-04-20 06:46:17]


Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlineikramerica From United States of America, joined May 2005, 21589 posts, RR: 59
Reply 30, posted (1 year 8 months 1 week 4 days 11 hours ago) and read 18144 times:

Yes, but no catastrophic event was imminent on the NH plane, the electrolyte in the battery is non-toxic, and the redesign was to further prevent something from happening that didn't actually happen in the one chance it had to do so.

The JL plane was on the ground and the "tall" fire happened after Boston fire broke the containment. In flight we don't know if it would have happened at all, or if the negative pressure would have worked as promised but are we to assume it wouldn't?

I'm glad they installed a sneeze guard, but the reality is that batteries fail, and one will fail again, and there will be an odor, and everyone will panic because this ridiculous grounding has conditioned everyone to be fearful.



Of all the things to worry about... the Wookie has no pants.
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 31, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 18137 times:
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And what caught fire on JL8's battery was the plastic wiring on the cells, not the cells themselves. This wiring has been replaced with a grade that has a significantly higher ignition point so even if all the cells enter thermal runaway, there may very well be no fire. I expect this wiring was tested as part of the re-certification, so even if it could catch fire, it sure has hell is not going to burn for hours.

User currently offlineairmagnac From Germany, joined Apr 2012, 321 posts, RR: 52
Reply 32, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 18107 times:

Quoting RobK (Reply 28):

Looking at it rationnally :
An airplane is flying through air so cold and with so little density as to kill any living being instantly, it's flying so fast that the rush of air and the pressure shocks would kill anything too. And there is only a few millimeters of material sperating the inside from the exterior. If flying low, the plane is still so fast that if it hits the ground, the difference of energy is enough to blast you half way to the moon (OK maybe not quite)
There are 2, sometimes 4, blazing infernos under the wings. Sometimes even directly attached to the fuselage. Usually there is another one in the back of the fuselage. Inside each inferno some parts are moving so fast that it is considered they can slice through anything if released.
All around the pax there are pipes holding highly corrosive fluid at 3000 or even 5000psi, to compare to the 100psi of pressure cleaning tools. Other pipes are transporting highly energetic air flows, and cables carry high power electrical currents. There are electrical connections everywhere, each one of which could trigger a spark. There are a whole bunch of high pressure containers within the aircraft, including the wheels or sometimes oxygen bottles. And on and on...

Every single one of these items, and many more, can kill you. Every one of them has been considered, the causes have been studied for means of prevention, and/or the consequences have been studied for means of mitigation. And the FAA/EASA/whomever gives their blessing for each one.

What makes the batteries so special ?



One "oh shit" can erase a thousand "attaboys".
User currently offlineB6JFKH81 From United States of America, joined Mar 2006, 2902 posts, RR: 7
Reply 33, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 17988 times:

Quoting KarelXWB (Reply 6):
It will take mechanics 4 to 5 days per airplane to install the new battery. Boeing is sending teams to their customers to assist with the replacement of the batteries.

4 to 5 DAYS per plane??    Okay, so being someone on the technical side of the industry I have a few questions about that:

> How many batteries per aircraft need to be replaced?
> Is there additional electrical re-work getting done on top of the battery swaps such as wiring, other components such as generators and whatnot?
> Are there any structural and/or safety changes being made in the structure surrounding the area the battery is in (brackets, insulation, additional/changed fire detection and suppression, etc.)?

4 to 5 days sounds a bit high for a battery swap which is why I ask, but I am not familiar with the inner workings of the 787. Thanks for any input!

~H81



"If you do not learn from history, you are doomed to repeat it"
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 34, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 17992 times:
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Quoting B6JFKH81 (Reply 33):
How many batteries per aircraft need to be replaced?

Two.

Quoting B6JFKH81 (Reply 33):
Is there additional electrical re-work getting done on top of the battery swaps such as wiring, other components such as generators and whatnot?

There is new wiring within the battery pack and I expect the wiring of the external connectors will be upgraded, as well.



Quoting B6JFKH81 (Reply 33):
Are there any structural and/or safety changes being made in the structure surrounding the area the battery is in (brackets, insulation, additional/changed fire detection and suppression, etc.)?

There will probably be some bracket changes to fit the larger containment vessel. There also will need to be plumbing run from that box to the fuselage shell to support the venting system.


User currently offlinecarbon787 From United States of America, joined May 2010, 71 posts, RR: 0
Reply 35, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 17939 times:

Quoting airmagnac (Reply 32):
Quoting airmagnac (Reply 32):
Looking at it rationnally :
An airplane is flying through air so cold and with so little density as to kill any living being instantly, it's flying so fast that the rush of air and the pressure shocks would kill anything too. And there is only a few millimeters of material sperating the inside from the exterior. If flying low, the plane is still so fast that if it hits the ground, the difference of energy is enough to blast you half way to the moon (OK maybe not quite)
There are 2, sometimes 4, blazing infernos under the wings. Sometimes even directly attached to the fuselage. Usually there is another one in the back of the fuselage. Inside each inferno some parts are moving so fast that it is considered they can slice through anything if released.
All around the pax there are pipes holding highly corrosive fluid at 3000 or even 5000psi, to compare to the 100psi of pressure cleaning tools. Other pipes are transporting highly energetic air flows, and cables carry high power electrical currents. There are electrical connections everywhere, each one of which could trigger a spark. There are a whole bunch of high pressure containers within the aircraft, including the wheels or sometimes oxygen bottles. And on and on...

Every single one of these items, and many more, can kill you. Every one of them has been considered, the causes have been studied for means of prevention, and/or the consequences have been studied for means of mitigation. And the FAA/EASA/whomever gives their blessing for each one.

What makes the batteries so special ?

this is one of the most 'makes sense' statement I have yet read in these threads since the start of the grounding!!


User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 36, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 17905 times:



Quoting B6JFKH81 (Reply 33):
4 to 5 DAYS per plane??    Okay, so being someone on the technical side of the industry I have a few questions about that:

It's not just a simple swap, space in the avionics bay is limited and you have to do some rewiring too. Mechanics must also drill a small hole in the fuselage to vent gasses from the box. Then you have to test everyting etc. They may also swap 1 battery at a time, so that would make 2.5 days per battery. Sounds plausible to me.

[Edited 2013-04-20 07:42:00]


Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlineairmagnac From Germany, joined Apr 2012, 321 posts, RR: 52
Reply 37, posted (1 year 8 months 1 week 4 days 10 hours ago) and read 17893 times:

Quoting ikramerica (Reply 30):
no catastrophic event was imminent on the NH plane, the electrolyte in the battery is non-toxic, and the redesign was to further prevent something from happening that didn't actually happen in the one chance it had to do so.

The JL plane was on the ground and the "tall" fire happened after Boston fire broke the containment. In flight we don't know if it would have happened at all, or if the negative pressure would have worked as promised but are we to assume it wouldn't?

Completely agreed, there apparently was no immediate danger in either case. But what may seem ridiculous to you is just proper saftey policies :

- you don't wait for an actual catastrophy to happen, it's much better to prevent than to react. Reacting to an actual catastrophy is very concrete and easy to visualise, but it's too late. Preventing means acting against something that has not happened yet, which makes it seem abstract and difficult to understand, but doesn't make it less useful. Actually, it's a lot more useful

- we are talking about extremely small probabilities. Regulations state that catastrophic events should have a probability of happening of no more than 1 in 1 billion flight hours. Even if the probability is 1 in 100 million, that's still too high, even though that means flying a 787 fleet for a cumulated total of 5700 years (2 batteries/plane) without even being certain of seeing the event happen even once (probability of 1 per X hours does not mean that you will be certain of having one event in X hours, it means that over a large repetition of X hours, the average occurence rate is one). These extremely remote probabilities may again make all this look very abstract and useless, but it's by rigorously dealing with these probabilities that aviation has become so safe

Shrugging it off and declaring the current design "good enough" is simply not acceptable. But there is also no need to call it a major catastrophy, a close-call or a near-accident. The truth, as often, lies somewhere in between those two extremes.

[Edited 2013-04-20 07:43:03]

[Edited 2013-04-20 07:46:52]


One "oh shit" can erase a thousand "attaboys".
User currently onlinePITingres From United States of America, joined Dec 2007, 1163 posts, RR: 13
Reply 38, posted (1 year 8 months 1 week 4 days 9 hours ago) and read 17195 times:

Quoting airmagnac (Reply 27):
UPSTREAM of the event, it is indeed still not known for certain what caused the problem. .....

This is a technically justified fix

The ground has been well covered, so I'll simply add that although I've not seen anything publicized along these lines, I'd be astonished if the fix did not also include some sort of improved recording and/or monitoring; so that if the charger and cell level changes don't suffice and another battery DOES poop itself in a similar manner, more data can be collected as to why, so that the underlying cause can be found and cured.

(and, of course, the containment improvements ought to ensure that any such failure is a non-event from an overall airplane status standpoint.)



Fly, you fools! Fly!
User currently offlineB6JFKH81 From United States of America, joined Mar 2006, 2902 posts, RR: 7
Reply 39, posted (1 year 8 months 1 week 4 days 9 hours ago) and read 17062 times:

Quoting Stitch (Reply 34):
Quoting KarelXWB (Reply 36):

Thanks for the extra info guys, the time now makes more sense.



"If you do not learn from history, you are doomed to repeat it"
User currently offlinePW100 From Netherlands, joined Jan 2002, 2594 posts, RR: 16
Reply 40, posted (1 year 8 months 1 week 4 days 8 hours ago) and read 16814 times:

Quoting KarelXWB (Reply 26):
It seems like this is not the case:

That is not entirely correct. Allow me to explain.

As I wrote in another 787 thread, it is perfectly legal to do all kind of work on an airliner before the documentation has been approved by the appropriate authorities, you just can not release the airframe to service. As long as you properly record all the work performed, there is no problem with carrying out the work, and wait with the release to service until the documentation has been approved. This practice happens on a daily basis with all kind of repair developments.

There is nothing stopping the Boeing teams from doing the preparations, such as removing components to allow access to the required areas. Theoretically, they could even do reworks like drilling holes in fuselages. There is off course a risk involved when the repair instructions as finally approved, deviate from the work already carried out. I.e. when unexpected changes are mandated by the approval authority. However I fully expect that Boeing is in continuous talking with the approval authority(s), and has a pretty good idea what to expect. So they will be very well able to balance any associated risk.

The main problem area is, that they can not ship any components that need to go on the airplane. These parts require design approval and production approval. Based on these approvals a release certification (Form 1 in EASA world, Form 8130 – I think – in FAA world) must be issued before the components can leave the production facility. As long as the appropriate Service Bulletins have no regulatory (FAA) approval, these components can not (legally) leave the boundaries of the production facility.

So once FAA signs off on the SB’s, you can rest assured that many many modification kits will ship out to support the already ongoing modification efforts.

Rgds,
PW100



Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
User currently offlineikramerica From United States of America, joined May 2005, 21589 posts, RR: 59
Reply 41, posted (1 year 8 months 1 week 4 days 6 hours ago) and read 15855 times:

Quoting airmagnac (Reply 37):
Completely agreed, there apparently was no immediate danger in either case. But what may seem ridiculous to you is just proper saftey policies :

Actually, its completely unprecedented.

There is no historical reason that the 787 was grounded in this fashion, yet the 777 was not after the BA crash, the A380 wasn't after the engine explosion, the A330 after the AF crash. It's completely inconsistent and stems from either paranoia or politics. Whenever I offer a political reason, its deleted. But let's just say powerful people in both parties are not fans of Boeing and leave it at that.



Of all the things to worry about... the Wookie has no pants.
User currently offlineRevelation From United States of America, joined Feb 2005, 12970 posts, RR: 25
Reply 42, posted (1 year 8 months 1 week 4 days 4 hours ago) and read 15450 times:

Quoting airmagnac (Reply 37):

Completely agreed, there apparently was no immediate danger in either case. But what may seem ridiculous to you is just proper saftey policies :

- you don't wait for an actual catastrophy to happen, it's much better to prevent than to react. Reacting to an actual catastrophy is very concrete and easy to visualise, but it's too late.

Earlier in the discussions I said I would have no issue with flying the unmodified 787, but also said I am glad the FAA took action because the public here and Japan were losing faith in the aircraft.

Quoting ikramerica (Reply 41):
Whenever I offer a political reason, its deleted.

It might be because you've been offering inflammatory accusations without any evidence.



Inspiration, move me brightly!
User currently offlinekalvado From United States of America, joined Feb 2006, 497 posts, RR: 0
Reply 43, posted (1 year 8 months 1 week 4 days 4 hours ago) and read 15331 times:

Quoting ikramerica (Reply 41):
There is no historical reason that the 787 was grounded in this fashion, yet the 777 was not after the BA crash, the A380 wasn't after the engine explosion, the A330 after the AF crash. It's completely inconsistent and stems from either paranoia or politics. Whenever I offer a political reason, its deleted.

Well, maybe because there is obviously no political reason?
Unlike the cases you mentioned, 787 demonstrated a PATTERN of failures.
In case of A380, engine explosion turned out to be a systematic problem with certain engine. Once it turned to be a pattern, subfleet was grounded until engines were repaired.
In case of 777 and 330 problem, although systematic, had low enough probability as it could be determined at the time of accident - so that issue could be fixed in less than extremely urgent fashion.
If any of those accidents occurred within first year of operation - e.g. before reliability was proven statistically - that could be a very different story.


User currently offlineart From United Kingdom, joined Feb 2005, 3398 posts, RR: 1
Reply 44, posted (1 year 8 months 1 week 4 days 4 hours ago) and read 15349 times:

It's very good to hear that the 787 will soon be back in service.

Boeing had a banner ad at the top of one of the pages on a.net (perhaps it's still there) giving an update on the 787's status, fullsome in its praise of the aircraft. Among the many virtues claimed is this:

Quote:
Environmentally responsible – the most fuel efficient commercial jet airplane ever.
http://787updates.newairplane.com/FA...&utm_campaign=UK-Contextual-Boeing

OK, promote your product but doesn't this go too far? If Boeing's claim were true why would any airline order A380 except to contend with the problem of slot constricted airports?


User currently offlineairmagnac From Germany, joined Apr 2012, 321 posts, RR: 52
Reply 45, posted (1 year 8 months 1 week 4 days 4 hours ago) and read 15320 times:

Quoting ikramerica (Reply 41):
777 was not after the BA crash, the A380 wasn't after the engine explosion, the A330 after the AF crash

In all of these cases, and in the cases of all the ADs issued over the years for all aircraft, the main cause(s) was (were) quickly narrowed down, even if the rigourous proof was not established for several months or years. Even amid the loads of BS claimed by the media, it took only a few days after AF447 to figure out it was probably due to a pitot icing + wrong pilot reaction, thanks to the ACARS messages. And within 3 weeks after BA38, airlines were already reviewing their fuel quality procedures to prevent icing problems :
http://web.archive.org/web/20080217204033/http://online.wsj.com/public/article_print/SB120277026942260315.html
And usually, solutions are found which can be implemented in the short term to reduce the likelihood of a repeat.

Also, in the cases of the 330 and 777, the accidents happened after an already long service life without major problems, giving confidence that an immediate repeat of these events was unlikely before the fixes were in place. As for the 380, it was an extremely serious situation, but the airframe proved it could resist to quite a battering and continue flying.

In the case of the 787 batteries, the causes of the overheat were unknown, and remain so to this day meaning no action could be taken to prevent a repeat. And it seems that there were worries about the possible effects of a similar battery failure under certain circimstances.
So IOW FAA knew there was a problem, did not know how its causes could be prevented, did not know how its consequences could be mitigated, and did not have enough experience with the aircraft to have any confidence. What else could they do but ground the plane till they had gathered more info ?

The grounding made sense, no need for conspiracy theories about paranoia or politics



One "oh shit" can erase a thousand "attaboys".
User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3432 posts, RR: 4
Reply 46, posted (1 year 8 months 1 week 3 days 18 hours ago) and read 14476 times:

Quoting RobK (Reply 28):
Well that's very reassuring for me as pax. Being over the middle of the Pacific at 39k and 3 hours from the nearest suitable airfield whilst having a raging inferno underway in the battery compartment would not bother me in the slightest. Nope, I'd be completely fine with that as the FAA said so

Better not fly then. EVERY battery technology in use on aircraft has the potential to cause fires, and they don't have containment systems in many cases.


User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 47, posted (1 year 8 months 1 week 3 days 7 hours ago) and read 14056 times:
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The only "raging inferno" caused by a battery on a commercial airliner you will ever encounter is going to be one in the overhead bin or under the seat when a laptop enters thermal runaway.

And in neither case will that "raging inferno" be contained inside a titanium box with minimal oxygen and a direct vent to the outside of the plane.

  


User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 48, posted (1 year 8 months 1 week 3 days 1 hour ago) and read 13719 times:

http://www.japantoday.com/smartphone...-up-to-200-boeing-787-test-flights
NH conducting 100-200 test flights throughout May and will resume service in June if all goes well.

Also:
http://www.japantoday.com/category/n...tra-safety-measures-for-dreamliner
More additional safety measures will be implemented by the transportation ministry, including more inspections on the battery and voltage monitors.

[Edited 2013-04-21 17:13:05]


Follow me on twitter: www.twitter.com/phx787
User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 49, posted (1 year 8 months 1 week 2 days 21 hours ago) and read 13368 times:

Quoting airmagnac (Reply 32):
There are 2, sometimes 4, blazing infernos under the wings. Sometimes even directly attached to the fuselage. Usually there is another one in the back of the fuselage. Inside each inferno some parts are moving so fast that it is considered they can slice through anything if released.
Quoting airmagnac (Reply 32):
Every single one of these items, and many more, can kill you. Every one of them has been considered, the causes have been studied for means of prevention, and/or the consequences have been studied for means of mitigation. And the FAA/EASA/whomever gives their blessing for each one. What makes the batteries so special ?

Exactly - I couldn't agree more. Below I tried a post with a similar theme but this keeps coming back.

"I think it all comes down to not trusting the engineering of the new robust vented containment vessel system. Please help me understand because I just don't get it. (1)-On the one hand you trust the engineering of the APU which is inside the fuselage and at 1200 hp puts out at least 100 times more heat, fire and smoke than any little burning battery ever could. (2)-On the other hand you don't trust the engineering of the new containment vessel system, which because of the present issues and implications to Boeing has probably received more attention in engineering than any comparable system on the airplane. Furthermore in (1) this fire and heat happens everytime the airplane flies. Both (1) and (2) would have been engineered to that aircraft statistical metric of 1:10^7 or whatever they use. Its likely the same statistic metric they use for two engines out."

If they don't trust the engineering then there are about a million other things they should be worried about on the airplane. For these people I would suggest either the bus or the train and then they might want to double check the safety metric, and I think they will find it less than 1:10^7.


User currently offlineneutrino From Singapore, joined May 2012, 661 posts, RR: 0
Reply 50, posted (1 year 8 months 1 week 2 days 20 hours ago) and read 13304 times:

Quoting twiga (Reply 49):
..............If they don't trust the engineering then there are about a million other things they should be worried about on the airplane. For these people I would suggest either the bus or the train and then they might want to double check the safety metric, and I think they will find it less than 1:10^7.

Fully agree. To some of these overly paranoid folks, even the train, bus, car or bicycle for that matter could be susceptible to catastrophic mechanical failures while they are riding on them. They are better off not living.



Potestatem obscuri lateris nescitis
User currently offlineneutrino From Singapore, joined May 2012, 661 posts, RR: 0
Reply 51, posted (1 year 8 months 1 week 2 days 19 hours ago) and read 13154 times:

http://economictimes.indiatimes.com/...batteries/articleshow/19672921.cms
...and the batteries system replacement/modification at JAL & ANA have begun. Could take as long as two months to complete the work on the two fleets. Timing for pax flights resumption not firmed yet.



Potestatem obscuri lateris nescitis
User currently offlineneutrino From Singapore, joined May 2012, 661 posts, RR: 0
Reply 52, posted (1 year 8 months 1 week 2 days 19 hours ago) and read 13281 times:

Meanwhile, at Air India, another Boeing team has joined a previous one already there.
They will work on at least two aircraft at a time, with first commercial domestic flight hopefully by the middle of next month and then followed shortly by international destinations. Some new routes are also being considered.
Looks like it's all systems go...full steam ahead.



Potestatem obscuri lateris nescitis
User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 53, posted (1 year 8 months 1 week 2 days 11 hours ago) and read 12913 times:

Quoting B6JFKH81 (Reply 33):
4 to 5 days sounds a bit high for a battery swap which is why I ask,


AOG teams works 24 hours on 12 hrs shifts. But somethings just can not be sped up.

Reason:

1) Working space is limitted. You can probably only get one or two mechanics in the area at any one time. This is a case where more people does not neccessary make things go faster.

2) When taking things appart, cleaning and preping the surfaces for re-assemble takes as much time if not even more than drilling and cutting.

3) Then there's all the waiting for the surface prep (alodine, primer, paint and sealant) to cure. Sometimes you can accelerate the cure with additional heat, but that may just change the cure time from 7 days to one day. With the fay surface sealant, you really want to make sure that thing cure completely before to take the airplane to altitude.

As for the raging inferno in the battery pack . . . as a comparison, does anyone have any data on how often those power supplies or tranformers in the EE bay go up in smoke? The energy release when one of those fail may even be worst than a battery failure.


bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinekanban From United States of America, joined Jan 2008, 3875 posts, RR: 27
Reply 54, posted (1 year 8 months 1 week 2 days 8 hours ago) and read 12667 times:
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Quoting bikerthai (Reply 53):
alodine, primer, paint and sealant

not to mention deburr and FOD removal


User currently offlinesonomaflyer From United States of America, joined Apr 2010, 1890 posts, RR: 0
Reply 55, posted (1 year 8 months 1 week 2 days 8 hours ago) and read 12636 times:
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Quoting bikerthai (Reply 53):
as a comparison, does anyone have any data on how often those power supplies or tranformers in the EE bay go up in smoke? The energy release when one of those fail may even be worst than a battery failure.

Its unclear what you are asking about. I don't know of anything other than the battery in the 787 to overheat. To date, we haven't seen any other hardware in the EE bay fail based on the information I've seen.

If you're asking about any aircraft anywhere in the world, that's a completely different issue. I don't recall any major incident (defined as a crash or emergency diversion/abort take-off) traced to a "transformer" or "power supply" blowing up.

UA had a divert due to an issue with the electrical panel in November 2012. That problem was traced to a bad batch and replaced.


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 56, posted (1 year 8 months 1 week 2 days 7 hours ago) and read 12540 times:

Quoting bikerthai (Reply 53):
As for the raging inferno in the battery pack . . . as a comparison, does anyone have any data on how often those power supplies or tranformers in the EE bay go up in smoke? The energy release when one of those fail may even be worst than a battery failure.

Now just as many of us are all getting comfortably smug about the resolution to the battery issues you decide to upset the apple cart. At this rate you will even have me riding the bus or tuning up my bicycle. I have seen transformers on residential streets blow up for no apparent reason.

1)-The 787 being all electric probably has x5 or more of these than any other aircraft.
2)-It is my understanding that there is no fire suppression (sprinklers) for obvious reasons in the EE bays.
3)-How are they contained (not in 1/8 inch thick ss)?
4)-Who makes them? Outsourced abroad? What oversight?
5)-Any info on past failures on aircraft and consequences?
6)-Is the reliability in that 1:10^7 hrs?

Thats why youv'e got me scared.    But can rationalize its one of the other million things to worry about.   


User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 57, posted (1 year 8 months 1 week 2 days 7 hours ago) and read 12499 times:

Quoting twiga (Reply 56):
Now just as many of us are all getting comfortably smug about the resolution to the battery issues you decide to upset the apple cart.

Nothing to worry about. The TR and Power converter I was talking about are the boxes that takes the AC power from the engines and convert them to DC power. I was wondering what happens if one of these fails.

Anyway Boeing's web site has a video on the battery fix. It was surprising to me to see how the containment box fits in the EE bay . . . slightly different than what was on one of the power point. Perhaps they rotate them differently depending on which battery it was. Lots of detailed design consideration to account for.

http://videos.web.boeing.com/video/1593

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlineKELPkid From United States of America, joined Nov 2005, 6428 posts, RR: 3
Reply 58, posted (1 year 8 months 1 week 2 days 5 hours ago) and read 12301 times:

Quoting RobK (Reply 28):
Being over the middle of the Pacific at 39k and 3 hours from the nearest suitable airfield whilst having a raging inferno underway in the battery compartment would not bother me in the slightest

Ahem, may I also remind you that there are two raging infernos already going (one on each wing?)   However, as the design of the turbofan engines is far more refined, people haven't been worrying about the stovepipes out on the wings since the first prototype of Mr. Whittle's wonder took flight during WWII...but at their heart, there is one intense inferno raging throughout the flight  



Celebrating the birth of KELPkidJR on August 5, 2009 :-)
User currently offlinehkcanadaexpat From Hong Kong, joined Dec 2012, 657 posts, RR: 3
Reply 59, posted (1 year 8 months 1 week 1 day 12 hours ago) and read 11897 times:

A nice pic in the attached article of what appears to be JA-808A getting the battery fix at Okayama airport where it got stranded when ANA decided to ground all its flights ahead of suspension by Japanese authorities.

http://www.theborneopost.com/2013/04...eplacing-787-dreamliner-batteries/

Cheers
A


User currently offlinelightsaber From United States of America, joined Jan 2005, 13551 posts, RR: 100
Reply 60, posted (1 year 8 months 1 week 1 day 11 hours ago) and read 11840 times:
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I love all the Goblins coming out of the closet! There are too many energy sources on an airplane to discuss in this thread! And if you had ever seen water hammer issues in an aircraft hydraulic system, you would understand how much safer in the long run the all electric aircraft will be. Unless one puts on high speed pressure transducers, one won't catch the water hammer even though it is fatiguing lines.

Quoting bikerthai (Reply 53):
1) Working space is limitted. You can probably only get one or two mechanics in the area at any one time. This is a case where more people does not neccessary make things go faster.

This is definitely a 'fix' best done before the tail is matted to the rest of the airframe. Cest la vie.

Quoting twiga (Reply 49):
If they don't trust the engineering then there are about a million other things they should be worried about on the airplane. For these people I would suggest either the bus or the train and then they might want to double check the safety metric, and I think they will find it less than 1:10^7.

   At some point let the planes fly as the best estimates have been done.


Everyone does realize the most likely time to die in air travel is the trip to the airport?

What everyone is overlooking is that an all electric airplane is *much* easier to diagnose when issues arise later down the line. Many of the issues that have to be found by eye in older aircraft will instead be self diagnosed on the 787 (and other modern aircraft). Note: The eyeball inspections are still required, just at longer intervals.

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 61, posted (1 year 8 months 1 week 1 day 8 hours ago) and read 11614 times:

The EASA today approved the battery design change.


Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 62, posted (1 year 8 months 1 week 1 day 8 hours ago) and read 11656 times:
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I've been following the NTSB Boeing 787 Battery Investigative Hearing today and it has been very informative on a variety of subjects. The hearings resume at 13:30 Eastern at http://www.capitolconnection.net/capcon/ntsb/ntsb.htm#

User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 63, posted (1 year 8 months 1 week 1 day 3 hours ago) and read 11410 times:
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I watched the entire proceedings and learned a great deal, but here is a summary of today's NTSB panel.

Please note that Mr. Trimble has a typo in the article. Where he says, "In neither incident did the battery failure prevent a risk to the overall aircraft, ...", it should say,"In neither incident did the battery failure present a risk to the overall aircraft, ..." as that was the testimony given by Mr. Bahrami

[Edited 2013-04-23 14:40:29]

User currently offlineRevelation From United States of America, joined Feb 2005, 12970 posts, RR: 25
Reply 64, posted (1 year 8 months 1 week 1 day 2 hours ago) and read 11243 times:

Quoting Stitch (Reply 63):
I watched the entire proceedings and learned a great deal, but here is a summary of today's NTSB panel.

Thanks for the interesting link.

Mike Sinnett says the nail test was too conservative and the heat test wasn't conservative enough (even though the current testing used the heat test) yet doesn't say what test would have been appropriate? Kind of confusing, no?

Another confusing area:

Quote:

For example, the NTSB has said that the certification standards were supposed to prevent such a battery failure from occurring in less than one in 10 million flight hours, yet both incidents occurred before the 787 fleet reached 50,000 flight hours.

Sinnett said that the "one-in-10 million" standard applies only in very limited conditions.

"That number applies to a failure of a cell for particular reasons," he says, while listing installation damage as an example of a root cause that would be allowed to occur more frequently than under the special condition standard.

Anyone want to provide us with more examples of the "very limited conditions" the "one-in-10 million" standard applies? It has been said here that the 10e7 number is for the entire chain of events to lead to catastrophic failure, so I imagine these conditions would be the ones where there was no other mitigation to break the chain, but that doesn't seem to point to battery installation damage as a valid example, no?



Inspiration, move me brightly!
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 65, posted (1 year 8 months 1 week 1 day 1 hour ago) and read 11211 times:
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Quoting Revelation (Reply 64):
Mike Sinnett says the nail test was too conservative and the heat test wasn't conservative enough (even though the current testing used the heat test) yet doesn't say what test would have been appropriate? Kind of confusing, no?

To be fair, he's not a battery engineer.  

Boeing worked with GS Yuasa to determine what tests were appropriate because GS Yuasa had the expertise. GE Yuasa believed that a cell being punctured by an external piece of FOD was the most likely event to cause a short circuit. GS Yuasa also testified that this test represented the most catastrophic form of short circuit because it caused a short across both the positive and negative terminals and therefore would generate the most volatile response.

Per testimony from Boeing, Thales and GS Yuasa, the only way they could get the battery cells to vent and catch fire during testing was to deliberately and seriously overcharge them - my understanding is they had to put a lot of voltage and current into it for an extended period of time to get the cell to enter thermal runaway. Even when Boeing went to the "heat test", the cell did not catch fire.



Quoting Revelation (Reply 64):
It has been said here that the 10e7 number is for the entire chain of events to lead to catastrophic failure...

Correct. The FAA went in with the assumption that an incident with a lithium-Ion battery could possibly result in the loss of the airframe and created the Special Conditions to apply to the battery system at an airframe level (not a battery or battery component level as many of us believed and/or argued) so that the chance of such a failure bringing down the plane was 10e7.

The FAA has multiple levels of risk, of which Catastrophic is the highest and could result in the loss of the airframe. Below that was Serious and so on. In their view, both NH692 and JL8 were Serious incidents.


User currently offlineJoeCanuck From Canada, joined Dec 2005, 5478 posts, RR: 31
Reply 66, posted (1 year 8 months 1 week 19 hours ago) and read 10912 times:

I've become very optimistic about this fix. I have no doubt that with the scrutiny of the problem, these mods will prevent any chance of an accident due to a battery fire.

I still suspect that Boeing and all involved in the battery are working for an even safer battery chemistry.

[Edited 2013-04-23 22:37:32]


What the...?
User currently offlinenimool From United Kingdom, joined Oct 2012, 97 posts, RR: 0
Reply 67, posted (1 year 8 months 1 week 14 hours ago) and read 10730 times:

apparently QTR 787 left LHR!


If its not Boeing im not Going!
User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 68, posted (1 year 8 months 1 week 13 hours ago) and read 10662 times:

Quoting nimool (Reply 67):

Correct! He's on the move!
Parked B787s, Where Are They? (by azncsa4qf744er Apr 11 2013 in Civil Aviation)



Follow me on twitter: www.twitter.com/phx787
User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 69, posted (1 year 8 months 1 week 12 hours ago) and read 10543 times:

Quoting Revelation (Reply 64):
Mike Sinnett says the nail test was too conservative and the heat test wasn't conservative enough (even though the current testing used the heat test) yet doesn't say what test would have been appropriate? Kind of confusing, no?

I think you got it backward.

""What we've since found out is that the nail penetration test, while it was believed at the time to be representative of a failure inside the cell and it was state of the art at the time, in retrospect I believe we don't feel it was conservative enough, . . .

The other test would have inserted a heating element inside the cell. Such a method "adds significant energy to the cell in the process of making it fail, and as a result it can mask the results by being too conservative""


As for not using the heat element to fail the cell in the first place, I can see his argument against adding extra heat into the test making it not representative. But what about the heat that is generated when overcharging the cell? Could that have been calculated and added to the test if you don't want to directly over charge the cells yourself.

Question: Do these cell fail consistently at specific overcharge level?

If they do not have a consistent value to which they will overheat, then it would make more sense to fail these cells via heating element than by overcharging them.

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5478 posts, RR: 31
Reply 70, posted (1 year 8 months 1 week 9 hours ago) and read 10248 times:

Quoting bikerthai (Reply 69):

If they do not have a consistent value to which they will overheat, then it would make more sense to fail these cells via heating element than by overcharging them.

The problem with that test is it doesn't give you a realistic failure sequence. The nail at least gives you a reaction to a dead short and overcharging is certainly realistic. Just heating the cells at most gives you a temperature/reaction graph which doesn't go towards solving real world issues.

Overcharging can happen and is a known cause of failure, as is the accumulation of charge/discharge cycles. The batteries aren't exposed to heat, except if a neighboring cell ignites and isolation can take care of that.

It seems just heating cells until they burst doesn't really accomplish much.



What the...?
User currently offlinena From Germany, joined Dec 1999, 10817 posts, RR: 9
Reply 71, posted (1 year 8 months 1 week 9 hours ago) and read 10253 times:

I took a photo of AIs dustcovered 787 fleet a few days ago, 4 of them in a row accompanied by a stored and equally dusty 777.

User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 72, posted (1 year 8 months 1 week 2 hours ago) and read 9901 times:

Quoting bikerthai (Reply 69):
Question: Do these cell fail consistently at specific overcharge level?

Good question. I know little about batteries but here are my thoughts. Like anything thats manufactured there is likely some variation in how much maximum charge a given cell recieves for the same charge input - it may vary by 1 or 2 or even 5% I don't know, I'm just using these numbers for discussion purposes. Now I'm not sure of this but in the origional battery didn't they just monitor the 'average' voltage of all 8 cells when they were charging, so if one cell was a bad actor that 5% one, this could short and cause the problem. I believe now they monitor (and perhaps they did before) the voltages of all the cells individually and shut the charging down based on the maximum of anyone cell. And with all the testing they have done they probably tightened the manufacturer's variation window for max charge by increased inspection tolerance. As we also know they have lowered the max charge amount (it would be intersting to know by what %) to further safeguard against shorting. Now that they have lowered the max charge rate, and raised the min charge rate it would be interesting to know the % loss of battery capacity.


Quoting JoeCanuck (Reply 70):
Just heating the cells at most gives you a temperature/reaction graph which doesn't go towards solving real world issues.
Quoting JoeCanuck (Reply 70):
The batteries aren't exposed to heat, except if a neighboring cell ignites and isolation can take care of that.

Yes, but the graph may not be linear with this chemistry and at some point it goes beserk - no? Hence the discussion about possible new Li-ion chemistries which are less sensitive to temperature/ heat. And to be honest I can't remember if the graph I saw was for internal heat from charging or for external heat applied.

Yes the cells are not exposed to 'external' heat unless one is toasting beside it as you mentioned. However to clarify, I'm not sure if you are discussing both external and internal heat or just external heat. There is 'internal' heat from battery chemistry while charging just like my laptop battery gets hot while charging, and that's why they have softend the charge rate on the new battery to mitigate internal temperatures/ heat.


User currently offlinetugger From United States of America, joined Apr 2006, 5797 posts, RR: 10
Reply 73, posted (1 year 8 months 1 week 2 hours ago) and read 9918 times:

Just read this and found it an interesting tidbit:

Quote:
The new battery setup has been installed on 10 787s that belong to airlines, and on nine more that have been built but not delivered, he said. Each installation takes about five days.
http://www.washingtonpost.com/busine...-acd6-11e2-9493-2ff3bf26c4b4_story

Tugg



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User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 74, posted (1 year 8 months 1 week 1 hour ago) and read 9794 times:

Quoting twiga (Reply 72):
Now that they have lowered the max charge rate, and raised the min charge rate it would be interesting to know the % loss of battery capacity.

Sorry correction. I ment max charge 'amount' (voltage) and min charge 'amount' (voltage).


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 75, posted (1 year 8 months 5 days 20 hours ago) and read 9442 times:

Quoting Revelation (Reply 64):
Sinnett said that the "one-in-10 million" standard applies only in very limited conditions.
"That number applies to a failure of a cell for particular reasons,"
Quoting Revelation (Reply 64):
Anyone want to provide us with more examples of the "very limited conditions" the "one-in-10 million" standard applies? It has been said here that the 10e7 number is for the entire chain of events to lead to catastrophic failure, so I imagine these conditions would be the ones where there was no other mitigation to break the chain, but that doesn't seem to point to battery installation damage as a valid example, no?

I have also been pondering these questions, because they also relate to, how do you compute safety at the overall airplane level of 1: 10^7 (1:100 million) from combining the various levels or layers of redundancies? Sometimes things can be better clarified if you hang numbers on them, however there is always the danger of being wrong (I was never good at statistics), but others that know better can always jump in and correct. Now I'm relatively new here and I don't recall seeing anything posted on this in the 400 odd pages of 787 battery issues, and since it relates to airplane safety in general it would surprise me if something on this wasn't posted somewhere before - any references?

Sinnett said that the "one-in-10 million" standard only applied to limited conditions, and he went on to say "that number applies to the failure 'of a cell' for particular reasons". I presume battery installation damage is not included in the metric because its not measurable and it would arise from someone not doing his job as expected, and is therefore one of those unknown unknowns, just like the Gimili glider by improper fueling, or two engines out simultaneously with Canada geese.

Now lets assume (a) is the first level/ layer of redundancy and (b) is the second level of redundancy and the overall combination safety metric at the airplane level is (c). So ( a) x (b) = (c). We always know (c) = 1:10^7 (1:100 million) and we always know either one of (a) or (b). Lets look at 1) Before battery fix. 2) After battery fix, and 3) Two engines out.

1) Before battery fix
--(a)----one cell short------------------------------1: 10^6 (1 in 10 million according to Sinnett)
--(b)----multiple cells (thermal runnaway)----1: 10 (by deduction)
--(c)----Safety metric overall airplane level--1: 10^7 (known)
Sinnett specifically said "a cell" so this leaves the metric for thermal runnaway at 1:10 and doesn't leave anything for the blue battery box, which I suspect was just built to contain and carry the cells.

2) After battery fix
--(a)----battery level--------------------------------1: 10^4 (1:100,000 assume bat. mods improve x2 from 1:50,000)
--(b)----containment vessel-----------------------1: 10^3 (1:10,000 by deduction)
--(c)----Safety metric overall airplane level---1: 10^7 (known) minimum
I would personally put the containment vessel at least as high if not x10 more than the battery because its an engineered known - unlike the battery so we are in that 1: 1 billion range

3) Two engines out - assume (a) = (b) - for reliability of engines
--(a)---one engine out------------------------------1: 5^7 (1 in 50 million) (by deduction)
--(b)---two engines out-----------------------------1: 5^7 (1 in 50 million) (by deduction)
--(c)---Safety metric overall airplane level-----1: 10^7 (known)
I haven't included the RAT here because I don't know the metric. In trans- oceanic flights they would know from a general sense the percentage of time the aircraft is in reachable distance of landing - so there would be some metric for this last level of redundancy. So including some number for the RAT would reduce the 1: 5^7 numbers shown for engine out. There is one thing that puzzles me and that is how does ETOPS figure in here without changing the 1: 10^7 metric? Because if the reliability of the remaining engine is good for say 3 hrs versus say 1 hr, its 3 times better and this is a metric.

Anyway I hope this helps clarify these issues. It's is my take on this subject and not being an expert welcome any correction and obviously any other opinions.


User currently onlinerwessel From United States of America, joined Jan 2007, 2421 posts, RR: 2
Reply 76, posted (1 year 8 months 5 days 20 hours ago) and read 9405 times:
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Quoting twiga (Reply 75):
3) Two engines out - assume (a) = (b) - for reliability of engines
--(a)---one engine out------------------------------1: 5^7 (1 in 50 million) (by deduction)
--(b)---two engines out-----------------------------1: 5^7 (1 in 50 million) (by deduction)
--(c)---Safety metric overall airplane level-----1: 10^7 (known)

Your math here has some issues. 1:5**7 is neither 1:50000000 nor is (1:5**7)**2 1:10**7.


User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 77, posted (1 year 8 months 5 days 20 hours ago) and read 9464 times:

Looks like NH could begin test flights next week.


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User currently offlineblrsea From India, joined May 2005, 1426 posts, RR: 3
Reply 78, posted (1 year 8 months 5 days 19 hours ago) and read 9451 times:

Wow, the cost of the fix is estimated at $465,000 per plane! Isn't that pretty high for a containment box and new improved battery? I remember someone posting that the battery costs a few thousands but still less than $50k. Would travel , stay and the actual fix for two batteries (main and APU batteries) cost that much??

FAA pegs cost of 787 battery fix at $465,000 per plane

Quote:
...
The FAA estimates the cost to airlines of modifying each jet with two of Boeing’s beefed-up batteries, containment boxes and venting tubes at $464,678.

For United, the sole U.S. operator of the jet with six 787s in service, that’s a total modification cost of $2.8 million.

However, the directive notes this cost “may be covered under warranty” from Boeing. The jet-maker is very likely to pick up this entire cost for all its customers.

At just over $23 million for all 50 jets in service worldwide, that’s a small fraction of the cost to the airlines from lost revenue while their planes were grounded.
....


[Edited 2013-04-25 22:23:54]

User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 79, posted (1 year 8 months 5 days 18 hours ago) and read 9390 times:

Quoting rwessel (Reply 76):
Your math here has some issues. 1:5**7 is neither 1:50000000 nor is (1:5**7)**2 1:10**7.

Thanks you are right - there is also an issue with 2) so will correct it as well. Just not used to working with so many dam zeros.

Here are the corrected versions, hope they are right this time.

2) After battery fix
--(a)----battery level--------------------------------1: 10^4 (1:100,000 assume bat. mods improve x2 from 1:50,000)
--(b)----containment vessel-----------------------1: 10^2 (1:1,000 by deduction)
--(c)----Safety metric overall airplane level---1: 10^7 (known) minimum
I would personally put the containment vessel at least x10 more than is shown because its an engineered known - unlike the battery so we are in that 1: 1 billion range

3) Two engines out - assume (a) = (b) - for reliability of engines
--(a)---one engine out------------------------------1: 10^3 (1:10,000) (by deduction)
--(b)---two engines out----------------------------1: 10^3 (1:10,000) (by deduction)
--(c)---Safety metric overall airplane level----1: 10^7 (known)


User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 80, posted (1 year 8 months 5 days 18 hours ago) and read 9381 times:

Looks like japan gave the green light. Flights from NH therefore can commence at anytime really. Keep an eye on flightaware.

http://www.japantoday.com/category/n...-to-allow-boeing-787s-to-fly-again



Follow me on twitter: www.twitter.com/phx787
User currently onlinerwessel From United States of America, joined Jan 2007, 2421 posts, RR: 2
Reply 81, posted (1 year 8 months 5 days 17 hours ago) and read 9324 times:
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Quoting twiga (Reply 79):
Here are the corrected versions, hope they are right this time.

2) After battery fix
--(a)----battery level--------------------------------1: 10^4 (1:100,000 assume bat. mods improve x2 from 1:50,000)
--(b)----containment vessel-----------------------1: 10^2 (1:1,000 by deduction)
--(c)----Safety metric overall airplane level---1: 10^7 (known) minimum
I would personally put the containment vessel at least x10 more than is shown because its an engineered known - unlike the battery so we are in that 1: 1 billion range

3) Two engines out - assume (a) = (b) - for reliability of engines
--(a)---one engine out------------------------------1: 10^3 (1:10,000) (by deduction)
--(b)---two engines out----------------------------1: 10^3 (1:10,000) (by deduction)
--(c)---Safety metric overall airplane level----1: 10^7 (known)

(2b) 1:10**2 is 1:100, not 1:1000
(2c) 1:10**7 is correct if (2b) is 1:10**3

(3a) (3b) 1:10**3 is 1:1000, not 1:10000
(3c) 1:10**7 is neither (1:10**3)**2 or (1:10**3)**2, 1:10**7 implies the two prior values should be approximately 1:3200


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 82, posted (1 year 8 months 5 days 17 hours ago) and read 9309 times:

Quoting blrsea (Reply 78):
Wow, the cost of the fix is estimated at $465,000 per plane! Isn't that pretty high for a containment box and new improved battery? I remember someone posting that the battery costs a few thousands but still less than $50k. Would travel , stay and the actual fix for two batteries (main and APU batteries) cost that much??

It does seem awfully expensive. I saw somewhere it was $16,000 per battery. So with upgraded battery, say $30,000 and containment box with accessories at $30,000 this gives $120,000 per a/c. Where is the other $345,000 going? Transportation and installation - say $120,000? And of course I almost forgot (I wouldn't make a good bean counter) there are overhead and management fees and we have to maximize expenses for tax write off - lets say $225,000 it seems fair.


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 83, posted (1 year 8 months 5 days 15 hours ago) and read 9219 times:

Quoting rwessel (Reply 81):
(2b) 1:10**2 is 1:100, not 1:1000(2c) 1:10**7 is correct if (2b) is 1:10**3(3a) (3b) 1:10**3 is 1:1000, not 1:10000(3c) 1:10**7 is neither (1:10**3)**2 or (1:10**3)**2, 1:10**7 implies the two prior values should be approximately 1:3200

Thanks again rwessel - will redo all 3 tables and finally get it right. Sorry for the inconvenience.
Now lets assume (a) is the first level/ layer of redundancy and (b) is the second level of redundancy and the overall combination safety metric at the airplane level is (c) for catostraphic failure. So ( a) x (b) = (c). We always know (c) = 1:10^7 (1:10 million hrs) and we always know either one of (a) or (b). Lets look at 1) Before battery fix. 2) After battery fix, and 3) Two engines out.

1) Before battery fix
--(a)----one cell short------------------------------1: 10^7 (1 in 10 million according to Sinnett)
--(b)----multiple cells (thermal runnaway)----1: 1 (by deduction) (they never expected this to happen)
--(c)----Safety metric overall airplane level--1: 10^7 (1: 10 million) (known)
Sinnett specifically said "a cell" so this leaves the metric for thermal runnaway at 1:1 and doesn't leave anything for the blue battery box, which I suspect was just built to contain and carry the cells.

2) After battery fix
--(a)----battery level--------------------------------1: 10^5 (1:100,000 assume bat. mods improve x2 from 1:50,000)
--(b)----containment vessel-----------------------1: 10^2 (1:100) ( by deduction)
--(c)----Safety metric overall airplane level---1: 10^7 (1: 10 million) (known) minimum
I would personally put the containment vessel at least x10 more because its an engineered known - unlike the battery so we are in that 1: 100 million range

3) Two engines out - assume (a) = (b) for reliability of engines
--(a)---one engine out------------------------------1: 3200 (approx) (by deduction)
--(b)---two engines out-----------------------------1: 3200 (approx) (by deduction)
--(c)---Safety metric overall airplane level-----1: 10^7 (1:10 million) (known)
I haven't included the RAT here because I don't know the metric. In trans- oceanic flights they would know from a general sense the percentage of time the aircraft is in reachable distance of landing - so there would be some metric for this last level of redundancy. So including some number for the RAT would reduce the 1: 3,200 hr numbers shown for engine out. There is one thing that puzzles me and that is how does ETOPS figure in here without changing the 1: 10^7 metric? Because if the reliability of the remaining engine is good for say 3 hrs versus say 1 hr, its 3 times better and this is a metric.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 84, posted (1 year 8 months 5 days 12 hours ago) and read 9127 times:

Quoting twiga (Reply 82):
It does seem awfully expensive. I saw somewhere it was $16,000 per battery. So with upgraded battery, say $30,000 and containment box with accessories at $30,000 this gives $120,000 per a/c. Where is the other $345,000 going?

There are quite extensive changes to the re-charging systems as well, plus wiring modifications, twiga; followed by exhaustive testing. And Boeing will no doubt have to send big teams of highly-skilled people to many parts of the world - and pay for their accommodation for several days in each location.; those people not being available on the production line will also cost money (in the form of production delays) back at home. And, of course, there's the problem that Li-ion batteries can't be shipped as ordinary freight any more, meaning a lot of special flights?

Comes back to the 'old story' that I encountered (quite a while ago now  ) when I first set out in business (in the construction field). An old hand telling me that, if I didn't want to risk disappointment, I should produce the most careful estimate I could; and then 'double the money I first thought of').   ...............



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinegators312 From United States of America, joined Jul 2011, 65 posts, RR: 0
Reply 85, posted (1 year 8 months 5 days 11 hours ago) and read 9043 times:
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How will this fix go for planes to be assembled or that are on the line now?

I assume at some point it will be incorporated into the line work rather than after assembly, any ideas which LN that would start with?


User currently offlineNYC777 From United States of America, joined Jun 2004, 5803 posts, RR: 47
Reply 86, posted (1 year 8 months 5 days 10 hours ago) and read 9016 times:

The FAA has published the amended AD for the 787 in today's Federal Register making the battery modification official:

AD.nsf/0/097ad1695f5e7b8e86257b590046307e/$FILE/2013-08-12.pdf" target="_blank">http://rgl.faa.gov/Regulatory_and_Gu...57b590046307e/$FILE/2013-08-12.pdf



That which does not kill me makes me stronger.
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 87, posted (1 year 8 months 5 days 10 hours ago) and read 8915 times:
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Following the FAA and EASA, the JTSB has approved NH and JL resuming 787 revenue flights.

User currently offlinesankaps From United States of America, joined Jan 2008, 2255 posts, RR: 2
Reply 88, posted (1 year 8 months 5 days 9 hours ago) and read 8907 times:

Quoting Stitch (Reply 87):
Following the FAA and EASA, the JTSB has approved NH and JL resuming 787 revenue flights.

It has approved it conditional on additional checks and tests: http://www.usatoday.com/story/travel...set-to-resume-787-flights/2115241/

"Japan is requiring ANA and JAL to take additional safety measures, including installation of a system that allows monitoring of battery voltage on the ground and test flights of all 787 aircraft. A first test flight is expected Sunday."

ANA plans to conduct 230 test flight prior to returning to revenue service:
http://www.reuters.com/article/2013/...mliner-japan-idUSBRE93P00520130426

"The test flight by ANA, the Dreamliner's top customer, comes after U.S. and Japanese authorities gave approval for flights to resume and will be the first of some 230 flights the airline has planned before allowing the jet to carry passengers."

June before revenue flights resume:
"A resumption of Dreamliner commercial flights would be around June, as safety improvements are expected to take several weeks to finish, airline officials said."


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 89, posted (1 year 8 months 5 days 8 hours ago) and read 8854 times:

Quoting NAV20 (Reply 84):
those people not being available on the production line will also cost money (in the form of production delays) back at home.

As you gathered I was just being silly. Boeing probably had to double or more their normal AOG teams and as you say they came off their production line - likely a pick of their best workers and you don't just get replacements out of thin air. Slowing line production would come under impact costs and it could be huge.
Quoting NAV20 (Reply 84):
Comes back to the 'old story' that I encountered (quite a while ago now ) when I first set out in business (in the construction field). An old hand telling me that, if I didn't want to risk disappointment, I should produce the most careful estimate I could; and then 'double the money I first thought of'). ...............

Agreed - Iv'e been there. There are lots of unknown unknowns in construction - we called them contingencies it's a nicer word to satisfy the bean counters.   


User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 90, posted (1 year 8 months 5 days 3 hours ago) and read 8727 times:

Quoting twiga (Reply 82):
It does seem awfully expensive. I
Quoting blrsea (Reply 78):
FAA pegs cost of 787 battery fix at $465,000 per plane

On the other thread Stitch posted a link to the actual AD.

The AD has the $400K+ strickly for parts!!!! Labor was estimated at about $9K.
Total mod is about $2+ mil.

That's alot of money. Don't know if the value is per airplane but from the hours estimated, it would jive with the estimated 5 days per airplane (two 12hrs shifts per day for an AOG team).

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinetortugamon From United States of America, joined Apr 2013, 3451 posts, RR: 11
Reply 91, posted (1 year 8 months 5 days 1 hour ago) and read 8642 times:

Quoting bikerthai (Reply 90):
The AD has the $400K+ strickly for parts!!!!

According to the former Chairman of the NTSB, that still may not be enough. The Times had an interesting opinion piece by James Hall today. He mentions self-certification, lack of learning from the Cesna incident, and overall lack of objective oversight as reasons to be concerned about flight safety. Interesting read and it appears to me that he makes some valid points, he does not seem to mention the merits of the current fix though but I suspect that is because he is not privy to the data or re-certification information any longer.

http://www.nytimes.com/2013/04/26/op...he-faa.html?ref=787dreamliner&_r=0

Also, his view seems to be supported by Ben Sandilands:
http://blogs.crikey.com.au/planetalk...er-787-why-it-must-be-recertified/

tortugamon


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 92, posted (1 year 8 months 4 days 14 hours ago) and read 8427 times:

Pretty good BBC story here which sheds some light on the scale of effort - and cost, and manpower - that has been necessary to deal with the problem up to now.

"Boeing said it put 200,000 engineer hours into fixing the problem, with staff working round the clock.

-----------------

"A total of 300 Boeing engineers, pooled into 10 teams, have in the past week been fitting the new batteries and their containment systems around the world."


Good short video too, showing the new 'containment':-

http://www.bbc.co.uk/news/business-22315317



"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 93, posted (1 year 8 months 4 days 13 hours ago) and read 8361 times:

NH and JL frames left at HND have moved to the eastern parking bay at the s.eastern portion of HND. All of them have airstairs attached to them and were receiving service yesterday. I am guessing monday will be the beginning of the test flights for the 787s out of HND.

If any of you have me on FB please send me a message if you see any of the 787s pop up on flightaware or FR24, as I'd love to make my way to catch it on takeoff.



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User currently offlinedenverdanny From United States of America, joined Sep 2007, 263 posts, RR: 0
Reply 94, posted (1 year 8 months 4 days 12 hours ago) and read 8310 times:

I don't know. I found this statement to be somewhat disturbing:

"Even if we never know root cause, the enclosure keeps the airplane safe, it eliminates the possibility of fire, it keeps heat out of the airplane, it keeps smoke out of the airplane, and it ensures that no matter what happens to the battery, regardless of root cause, the airplane is safe," he said, adding "in some ways it almost doesn't matter what the root cause was."

http://www.denverpost.com/breakingne...m-ensures-787-safety#ixzz2RfS4deLV

If you don't know what the problem is/was, then how do you know the solution will solve it? How do you know what the consequences of failure will be? I don't know or believe the problem is a big one, but I just find that statement to be somewhat illogical and full of hubris. Probably an analogy with the Titanic isn't the best, but if your solution to a rupture in the ship is containment, what happens when you don't foresee ruptures across a wider area? Have they, or can they, foresee all the issue here, especially in light of a statement saying they don't even know what the problem was?


User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 95, posted (1 year 8 months 4 days 11 hours ago) and read 8257 times:
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Quoting denverdanny (Reply 94):
How do you know what the consequences of failure will be?

We've seen the consequences of failure - the battery vents liquified electrolyte and the plastics inside and outside the box catch fire.

The new plastics can handle significantly higher temperatures than what the batteries exhibit when in thermal runaway, so they should no longer catch fire. And even if they do, they can't burn long enough or hot enough to cause the new containment box to fail.

And vented, liquified electrolyte now has only one exit path - directly outside the plane.



Quoting denverdanny (Reply 94):
Probably an analogy with the Titanic isn't the best, but if your solution to a rupture in the ship is containment, what happens when you don't foresee ruptures across a wider area?

The designers of the Titanic knew how many compartments they could flood and remain afloat. The damage extended past that number so the ship sank.

Where the designers failed was in not extending the watertight bulkheads all the way to the top deck of the ship. Failing to do so allowed the compartments to flood more quickly as once one compartment flooded sufficiently, water spilled over to the next compartment and increased it's flooding rate. If they had extended the bulkheads to the top, the ship would have stayed afloat a fair bit longer, allowing for a more orderly and complete evacuation and perhaps even long enough for the Carpathia to have arrived and assist.

To bring that back to the 787, if Boeing had started with plastics capable of resisting high temperatures, there may not have been a fire on JL8.

[Edited 2013-04-27 06:31:58]

User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 96, posted (1 year 8 months 4 days 11 hours ago) and read 8244 times:

Quoting denverdanny (Reply 94):
Probably an analogy with the Titanic isn't the best, but if your solution to a rupture in the ship is containment, what happens when you don't foresee ruptures across a wider area?
Quoting denverdanny (Reply 94):
Have they, or can they, foresee all the issue here, especially in light of a statement saying they don't even know what the problem was?

Oddly enough, denverdanny, the Titanic probably 'proves the reverse case' in many ways. She was one of the first ships built with watertight bulkheads. Had she hit the iceberg head on, she probably wouldn't have sunk; but the officer of the watch ordered a turn, hoping to avoid hitting the iceberg at all. This proved to be the 'worst possible case,' in that instead of hitting the iceberg head on (damaging only the bows) the Titanic 'scraped along it,' opening up a lot of the watertight compartments. Enough, in fact, to cause the ship to sink; instead of just having to limp home with smashed bows, but still having enough intact watertight compartments to stay afloat. Exactly the situation you refer to - to much damage to too many areas............

We have to bear in mind that neither of the 787s that had battery fires crashed, and no-one got hurt. One of the incidents was actually on the ground, with no-one at all in any real danger. So, in 'normal officialese,' the two cases were 'incidents,' not 'accidents.' Arguably, therefore, the grounding was (and so far remains as) an over-reaction on the official side? I can't personally recall any other (flying) case in which a single non-fatal flying 'incident' caused the grounding of an entire type?

Can't help feeling that the FAA over-reacted; perhaps because the carbon-fibre 787 is a revolutionary design. Which is perhaps ironic, given that the 787's basic design, revolutionary as it may be, had nothing at all to do with either incident? The basic cause of the fires HAS to have been the Li-ion batteries - nothing at all to do with carbon fibre?

[Edited 2013-04-27 06:37:51]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently onlinepar13del From Bahamas, joined Dec 2005, 7717 posts, RR: 8
Reply 97, posted (1 year 8 months 4 days 11 hours ago) and read 8234 times:

Quoting denverdanny (Reply 94):
If you don't know what the problem is/was, then how do you know the solution will solve it?

The solutions being implemented has nothing to do with the root cause, it is to prevent any damage to the a/c from any failure of the battery whether catastrophic or minor, essentially the solution contains the battery. Additions are also being made based on current knowledge to mitigate operational items that may cause battery failures.

Quoting denverdanny (Reply 94):
How do you know what the consequences of failure will be?

The type chemicals used in this type battery and their properties are well known, the results / effects of thermal runaway is well known, so insulating against these damaging effects can be accomplished.


User currently offlineRevelation From United States of America, joined Feb 2005, 12970 posts, RR: 25
Reply 98, posted (1 year 8 months 4 days 10 hours ago) and read 8180 times:

Quoting NAV20 (Reply 92):
Good short video too, showing the new 'containment':-

Thanks for the interesting link. The one you posted now just shows an interview with Randy Tinseth.
The following now shows the containment:
http://www.bbc.co.uk/news/business-22319537

Quoting denverdanny (Reply 94):
If you don't know what the problem is/was, then how do you know the solution will solve it?

You don't know what the problem was, but:
a) you know a lot of things it could have been and have addressed them, and:
b) you know what damage a worse case failure could cause and have allowed for it.

I'm sure everyone involved would have loved to have nailed the root cause, but the key evidence of that all burned up.

Indeed Boeing is taking the risk of another battery cooking off at any point in time but of course they were taking that same risk from the first flight onward.

Personally I'm confident such an event will end with nothing more than laundry bills to show for it, but I also hope that it doesn't happen too soon if ever.



Inspiration, move me brightly!
User currently offlinedenverdanny From United States of America, joined Sep 2007, 263 posts, RR: 0
Reply 99, posted (1 year 8 months 4 days 8 hours ago) and read 8090 times:

Quoting Stitch (Reply 95):
We've seen the consequences of failure - the battery vents liquified electrolyte and the plastics inside and outside the box catch fire.

The new plastics can handle significantly higher temperatures than what the batteries exhibit when in thermal runaway, so they should no longer catch fire. And even if they do, they can't burn long enough or hot enough to cause the new containment box to fail.

And vented, liquified electrolyte now has only one exit path - directly outside the plane.

But... what if it's a symptom of another problem? Since they seem to be admitting they don't know the exact problem, then have they sufficiently addressed it? Oh well. Maybe this will "solve" things, if you can have a solution not knowing the problem. I just think it's a red flag of sorts. Another perhaps poor analogy would be the Comet--sending that back out before discovering the cause and having another accident. Then, having to go back to underwater fuselage testing and having the rupture/explanation.


User currently onlinePITingres From United States of America, joined Dec 2007, 1163 posts, RR: 13
Reply 100, posted (1 year 8 months 4 days 8 hours ago) and read 8096 times:

Quoting denverdanny (Reply 94):
If you don't know what the problem is/was, then how do you know the solution will solve it? How do you know what the consequences of failure will be? I don't know or believe the problem is a big one, but I just find that statement to be somewhat illogical and full of hubris.

Not meaning to pile on, but ... this sort of thing is perhaps a lot more common in engineering than non-engineers realize. It has happened any number of times to me, in software, thus:

The customer reports an occasional problem that crashes the database. It's not reproducible, and the existing logs and traces don't help. So, you start reading the code in that area. Maybe you find some places where the house of cards is stacked a little too high, even if you can't reason your way from there to the crash. So what you do is make the existing code more robust, and you try to add code to catch the bad state sooner (which is usually some sort of "impossible, can't happen" state that happens anyway), and you repair or recover from it as nicely as possible. 99 times out of 100 the problem goes away and we never see it again. Did you fix it, or was it just a bad roll of the dice, or cosmic rays, or what? You don't know and you'll never know, but as far as the customer is concerned it's fixed.

Engineering a battery fix is probably easier since at least you're dealing with a known energy source with a known and finite capacity and output. You assume that the battery will generate as much heat as is physically possible, and you contain it. It's mostly an exercise in thermodynamics and materials engineering, I should think. The battery might still go off (and contrary to some things I've seen written, there WERE changes to address that too), but at least it should now be a non-event at the aircraft level.



Fly, you fools! Fly!
User currently offlinekanban From United States of America, joined Jan 2008, 3875 posts, RR: 27
Reply 101, posted (1 year 8 months 4 days 7 hours ago) and read 8102 times:
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Here's the latest Av Herald summation and some new diagrams from the Japanese investigation.

The basic problem with finding some root causes is the evidence is destroyed, so one has to go with what could have happened that would result in like what remains. while nobody will say they know for sure what the cause was, they have narrowed it down to some variables that can be either controlled better or the failure result controlled better.


User currently offlineRevelation From United States of America, joined Feb 2005, 12970 posts, RR: 25
Reply 102, posted (1 year 8 months 4 days 7 hours ago) and read 8190 times:

Quoting PITingres (Reply 100):
and you repair or recover from it as nicely as possible

Just watched an engineer commit a fix that said "if X fails, retry three times". Asked him why three was the chosen value and he said "well, once isn't enough and more than three is too much". Doh! Bottom line: No one really likes such fixes, but it's better than the customer having outages.

Quoting PITingres (Reply 100):
Did you fix it, or was it just a bad roll of the dice, or cosmic rays, or what?

In my experience, such things do eventually come back, but it seems Boeing is prepared for that.

Eventually one will go poof, the pax will smell something funny or the pilots won't like the looks of the error messages, the plane will be diverted, the pax will hit the chutes, and the laundry bills will be paid. Hopefully no worse than that, and hopefully a long ways down the road from now.



Inspiration, move me brightly!
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 103, posted (1 year 8 months 4 days 7 hours ago) and read 8174 times:
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Quoting denverdanny (Reply 99):
But... what if it's a symptom of another problem? Since they seem to be admitting they don't know the exact problem, then have they sufficiently addressed it?

Yes.

With the new containment and venting system, no matter how or why it happens, should all eight cells in the battery enter thermal runaway and vent, the containment system will prevent that from affecting the safety of the airframe and the people aboard.

The cause is no longer relevant from the standpoint of the safety of the system.

The cause is relevant from the standpoint of the effectiveness and reliability of the system.


User currently offlineRevelation From United States of America, joined Feb 2005, 12970 posts, RR: 25
Reply 104, posted (1 year 8 months 4 days 6 hours ago) and read 8134 times:

Quoting Stitch (Reply 103):
The cause is relevant from the standpoint of the effectiveness and reliability of the system.

And IMHO so is the trust the public has in Boeing, at least to some degree, and for some period of time.

IMHO this is to some degree at risk, since even if the containment works, if the plane ends up on the ground with the escape chutes out some time in the near future, it'll be pretty ugly for Boeing.

You might phase this as a 'reliability issue', but IMHO it'd be more than that.



Inspiration, move me brightly!
User currently offlinetortugamon From United States of America, joined Apr 2013, 3451 posts, RR: 11
Reply 105, posted (1 year 8 months 4 days 6 hours ago) and read 8144 times:

Quoting denverdanny (Reply 99):
But... what if it's a symptom of another problem?

If something goes wrong with the battery again I am reasonably confident that it will happen while the plane is on the ground as the batteries are not utilized in flight. In which case, if this $500k box doesn't do what a bunch of smart people and smart peoples' people think it will do then I will get a chance to try out one of those fancy slides while on the ground. It would have been great if they found the source though. This is definitely less than ideal, I agree. I am not used to accepting that either.

All kidding aside though I really gained some comfort with this fix when I read that when they tried to overheat a cell, it vented but all of the other cells kept functioning for a long while and the temperature in the box was less than half what the temperature was pre-fix. And when they introduced a fire it wouldn't stay lit. And when they made it stay lit the box handled something like 5X what they expect it to need to. And again, this battery does not need to be working when they plane is in the air so as far as I am concerned they will have an expensive fix with another $500k box but none of the passengers should be the wiser. It sounds pretty redundant and shouldn't have an impact at the 'aircraft level'. We all hope!

tortugamon


User currently offlinekanban From United States of America, joined Jan 2008, 3875 posts, RR: 27
Reply 106, posted (1 year 8 months 4 days 4 hours ago) and read 8025 times:
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here's the link I forgot to post http://avherald.com/h?article=45c377c5&opt=0

User currently online7BOEING7 From United States of America, joined Oct 2012, 1772 posts, RR: 16
Reply 107, posted (1 year 8 months 4 days 4 hours ago) and read 8024 times:

Good website for ANA battery and other information:

http://www.ana.co.jp/wws/japan/e/local/common/share/boeing787info/


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 108, posted (1 year 8 months 4 days 1 hour ago) and read 7936 times:

Quoting denverdanny (Reply 99):
But... what if it's a symptom of another problem? Since they seem to be admitting they don't know the exact problem, then have they sufficiently addressed it? Oh well. Maybe this will "solve" things, if you can have a solution not knowing the problem. I just think it's a red flag of sorts.

Let me have a try at answering your question(s). I don't know how up to date you are on all thats been going on so its a bit of a summary. We seem to be discussing all the issues together and things tend to get a bit muddled. I think it will become a bit clearer if we separate the issues and compare the before and after the fix. This way we can discern the differences. (1) Before battery changes - broken down to two items (a) Battery - cells, charging etc. and (b) containment box. (2) After 'battery system' fix (a) Battery - cells, charging etc and (b) new containment box with vent tube.

(1) Before Battery Changes
(a) Battery - cells, charging etc. Issue - shorted and burnt with thermal runnaway in two incidents 1:50,000 event. Boeing had designed this for a 1: 10 million event.

(b) Blue battery containment box with 1/32 in thick aluminum alloy lid and a dozen or so flat head screws, was in my opinion not designed to contain anything, and was for the sole purpose of safely securing and carrying the battery cells. And I believe this did not figure in Boeings metric for safety - all the eggs being in (a). However this blue battery box did manage to contain things to some degree even though the lid came partly off and there was some bulging. For those that question this opinion - How safely would you sleep if you had one of those steel box gas fireplaces in the middle of your living room, and it was made of 1/32 inch thick tin?

(2) After 'Battery System' Fix
(a) Battery - cells, charging etc. Although they have not found 'root' cause, PITingres covered this well in his analogy with fixes to database crashes. Don't want to repeat whats been covered in so many posts - but its a logical, scientific shotgun approach that will certainly mitigate the unknown issues - to what degree we don't know. And because from an engineering perspective you can't engineer with any certainty for one of those unknown unknowns, the only way to gaurantee absolute safety at the airplane level to 1:10 million, which apparently is the same ultimate safety level they use for everything else on the airplane, is to go to (b) below. If batteries keep toasting too often, it will simply be a cost, inconvienience and maintenance issue for Boeing and their clients and not a safety issue. It will be like burning the buns in a galley oven - nobody will even know!

(b) Stainless steel 1/8 inch thick vented containment box/ vessel. (To me the word vessel implies withstanding pressure)
PITingers did a good job on this in post #100 but to elaborate further. Now we are engineering for knowns such as the total amount of energy in the battery cells and the rate of reaction and heat output. What we are dealing with here is the rates of change of about 4 items happening simultaneously and capturing the maximums of temperature, heat and pressures in order to design the containment vessel. This is not rocket sience since the basic principles of thermodynamics were established in or about the 1850's when engineering for steam engines. I am not an expert in this field but am aware, as most engineers take some courses in thermodynamics, of the math (calculus in this case) and principles involved in solving these problems. For the experts its as simple as 2+2 = 4 and for a known energy source every maximum for temperature, pressure, heat and heat transfer can be computed accurately, and later verified by testing. And with engineering and material science the box can be sized (volume comes into the calculus) and designed that "no fire, heat, temperature or pressure" event will effect anything in the EE bays. Its as fool proof as my 3/16 inch thick steel fire box for my gas fireplace that sits in the middle of my living room floor, and I sleep comfortably 24/7 for 5 months a year. My engineering friends in the oil and gas industry tell me they design similar pressure vessels on a daily basis - so the science is extremly well founded.

Its only human nature to be concerned or afraid of what you don't know or fully understand - I hope I've eased your mind just a little bit.   


User currently offlinercair1 From United States of America, joined Oct 2009, 1357 posts, RR: 52
Reply 109, posted (1 year 8 months 4 days 1 hour ago) and read 7906 times:
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Quoting denverdanny (Reply 94):
If you don't know what the problem is/was, then how do you know the solution will solve it? How do you know what the consequences of failure will be? I don't know or believe the problem is a big one, but I just find that statement to be somewhat illogical and full of hubris.

Many times when you go to the doctor - they do not know what the "root cause" is - they treat the symptoms and you get better. This is what Boeing did here - they treated the symptoms of a failure they did not know the root cause of.

Quoting Revelation (Reply 102):
Eventually one will go poof, the pax will smell something funny or the pilots won't like the looks of the error messages, the plane will be diverted, the pax will hit the chutes, and the laundry bills will be paid. Hopefully no worse than that, and hopefully a long ways down the road from now.

No they won't. If one goes poof - the smoke/electrolyte is ejected overboard. The passengers will know nothing about it and they certainly will not smell it. The pilots will get advisory messages about a battery failure, but that is all.
I suggest you review what the "fix" is.



rcair1
User currently offlinePHX787 From Japan, joined Mar 2012, 7975 posts, RR: 19
Reply 110, posted (1 year 8 months 4 days ago) and read 7873 times:

For those who care:

NH is operating a "symbolic" test flight today (a day earlier than what was previously announced, i'm assuming for the golden week holiday) from HND, with CEOs from NH and Boeing on board.

Took off a while ago:


[Edited 2013-04-27 17:51:00]


Follow me on twitter: www.twitter.com/phx787
User currently offlinecornutt From United States of America, joined Jan 2013, 338 posts, RR: 1
Reply 111, posted (1 year 8 months 3 days 22 hours ago) and read 7769 times:

Quoting denverdanny (Reply 99):
Another perhaps poor analogy would be the Comet--sending that back out before discovering the cause and having another accident. Then, having to go back to underwater fuselage testing and having the rupture/explanation.

I don't think that's a good analogy. In the Comet case they didn't have any idea what happened -- one minute the plane was flying, and the next minute it wasn't, and that's all they knew. In the 787 battery issue, we know exactly what happened -- the battery overheated. Admittedly we don't know why. But in this particular case it turns out to be possible to implement a work-around, if you will. The battery contains a finite amount of energy; design a box that can contain that amount plus a design margin, add a mechanism to vent the gases, and the problem is literally boxed in.

Admittedly this does not satisfy the engineering mind, and it's less than ideal from an operational standpoint. But it's become apparent that root-cause answers are not going to be found easily. You can think of the containment solution as buying time. It gets the system up to the certification standard well enough so that research on the battery itself can continue without the pressure to come up with an immediate answer.


User currently offlineNAV20 From Australia, joined Nov 2003, 9909 posts, RR: 36
Reply 112, posted (1 year 8 months 3 days 14 hours ago) and read 7644 times:

Quoting cornutt (Reply 111):
But it's become apparent that root-cause answers are not going to be found easily.

There's another possibility - that there was no actual 'root cause,' that (as with most malfunctions/accidents) there was in fact a combination of circumstances. Boeing have in fact addressed the problem 'across the board' - increasing separation/insulation between the cells, making the voltages less demanding, improving the wiring and recharging arrangements, improving the 'containment' etc. Time will tell, but my feeling is that they adopted the right ('belt and braces') approach.

Their reward is that the aeroplane has now been cleared to re-enter service. Full marks to them, and also to the FAA, for taking a quick (and, in my view, entirely correct) decision.

Just plain terrific that the aeroplane looks like being back in full service within a month or so.

[Edited 2013-04-28 03:29:11]


"Once you have flown, you will walk the earth with your eyes turned skywards.." - Leonardo da Vinci
User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 113, posted (1 year 8 months 3 days 7 hours ago) and read 7513 times:

Quoting NAV20 (Reply 112):
Quoting cornutt (Reply 111):But it's become apparent that root-cause answers are not going to be found easily.
There's another possibility - that there was no actual 'root cause,' that (as with most malfunctions/accidents) there was in fact a combination of circumstances. Boeing have in fact addressed the problem 'across the board' - increasing separation/insulation between the cells, making the voltages less demanding, improving the wiring and recharging arrangements, improving the 'containment' etc. Time will tell, but my feeling is that they adopted the right ('belt and braces') approach.

I agree - with root cause its either (a) one item or (b) combination of items. The NTSB and everyone is fixated on (a) and for obvious reasons its the only one you can logically trace for that smoking gun. Finding (b) would be much more elusive if not near impossible, especially if there were three or more items involved - that is six variables to tinker with. I think a good analogy would be baking bread - something I've just taken up. There are about 4 or 5 items that have to be got right in combination otherwise it won't turnout, and it involves tinkering with them all until you get it right. After about ten tries I finally have the right combination. Boeings systematic approach or logical tinkering with known items that can cause problems will very likely work.

If the battery metric was only doubled to 1:100,000 hrs from the changes and an airline had 50 aircraft in its fleet. For about 200,000 fleet hrs/year that would mean 2 battery change outs/ year - not a big deal about 3 hrs/ per a/c. How many times would a similar fleet change a burst tire from landing/ year - probably about the same. So to all those that were critical of Boeing, about being progressive in moving the goal post forward in going to Li-ion batteries instead of Ni-Cad, if you check a fruit tree where does the fruit grow, around the trunk, or on the branches, where you have to reach for it? Who do you admire in people, companies or goverments the former or the latter?


User currently offlineDashTrash From United States of America, joined Aug 2006, 1565 posts, RR: 2
Reply 114, posted (1 year 8 months 2 days 20 hours ago) and read 7325 times:

Quoting airmagnac (Reply 32):

What makes the batteries so special ?

Ask UPS. They lost a 747-400 and a DC-8 to these things. They aren't the only aircraft that have been lost. We've been trying to get them out of the cargo holds for years now, and Boeing has now built an entire airplane around them.

We have years of experience with 3000 psi hydraulics, pneumatics, fuel storage, fuel transfer, electrickery of both AC and DC variety, high and low voltage / amperage. These batteries are still infants in the aviation world, and they were throwing tantrums.

Funny thing about this thread. I haven't read many of the replies, and absolutely none were from pilots flying these things. I frequent plenty of pilot message boards, and few of us look at the 787 without a very skeptical eye. Most of us would have strapped on any other Boeing aircraft even in their flight test modes. Not so much the 787. At least until it's been around a while without smoking.


User currently offlinemoriarty From Sweden, joined Jan 2006, 190 posts, RR: 0
Reply 115, posted (1 year 8 months 2 days 14 hours ago) and read 7157 times:

Guess Boeing has quite a challenge restoring confidence in the plane. I've seen several ad-banners on various sites from Boeing with a link to the press release about resuming 787 operations. Guess ad costs are somewhat smaller than the ones for the lost confidence in the plane, not to mention the grounding itself.

I think Boeing builds great planes and I understand they take security very serious. So I really wonder how on earth it could come to this. Let's just hope the rest of the career of the 787 is flawless. I think it deserves that.



Proud to part of www.novelair.com.
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5478 posts, RR: 31
Reply 116, posted (1 year 8 months 2 days 6 hours ago) and read 7016 times:

Boeing and the FAA have prevented a battery fire from bringing down a 787...which is not the same as preventing a battery fire from starting...(though they've taken steps to further prevent that as well).

Nothing on a plane is 100% fail safe, including the pilots, and any battery can catch fire. What they've done is to prevent any fire from escaping the box and damaging the aircraft...which is a pretty safe step.

The amount of fuel feeding, and the temperatures of, a potential battery fire are known so building an enclosure to contain the worst case scenario is fairly straight forward. Once the threat of a battery fire spreading is eliminated, then the threat to the plane is eliminated.

I suspect Boeing is working on a less volatile battery chemistry in the long run, but this step certainly satisfies the safety aspect of the battery dangers.

It's not much different than preventing the heat from engines from igniting the fuel tanks, a mere meter or so away.

What caused the batteries to catch fire is unknown but the properties of one of these batteries catching fire are known...and as long as the box can contain any fire from within, then I have no qualms about flying on a 787.



What the...?
User currently offlineXT6Wagon From United States of America, joined Feb 2007, 3432 posts, RR: 4
Reply 117, posted (1 year 8 months 2 days 3 hours ago) and read 6852 times:

Quoting moriarty (Reply 115):
Guess Boeing has quite a challenge restoring confidence in the plane. I've seen several ad-banners on various sites from Boeing with a link to the press release about resuming 787 operations. Guess ad costs are somewhat smaller than the ones for the lost confidence in the plane, not to mention the grounding itself.

These ads are aimed at investors, not at anyone else in the industry.


User currently offlinercair1 From United States of America, joined Oct 2009, 1357 posts, RR: 52
Reply 118, posted (1 year 8 months 2 days 2 hours ago) and read 6767 times:
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Quoting DashTrash (Reply 114):
We've been trying to get them out of the cargo holds for years now, and Boeing has now built an entire airplane around them.

Large shipments of Li and LiIon batteries in cargo - potentially not safely packed - are a far different problem than 2 batteries designed and certified as part of the aircraft. And - BTW - many aircraft have LiIon batteries throughout them.
Hardly is the 787 designed "around them" for goodness sake. If you want to talk about something Boeing has designed around it is either composites or the 'more electric' architecture. BTW - the latter could work perfectly well without LiIon batteries.

Quoting DashTrash (Reply 114):
Funny thing about this thread. I haven't read many of the replies, ....

Which means you can't really make an informed statement about the contents of them.

There have been plenty of negative comments about the 787 as well as positive, from a wide variety of sources. I think there are plenty of pilots who would be happy flying the 787 - thrilled. The key is to recognize that the vocal ones tend to be the negative ones. That is true in general - not just here. Haven't you ever heard the adage - a dissatisfied customer will tell 10 others. A satisfied customer - maybe 1. Not a lot different here.



rcair1
User currently offlinePW100 From Netherlands, joined Jan 2002, 2594 posts, RR: 16
Reply 119, posted (1 year 8 months 1 day 8 hours ago) and read 6590 times:

Quoting DashTrash (Reply 114):
Ask UPS. They lost a 747-400 and a DC-8 to these things. They aren't the only aircraft that have been lost. We've been trying to get them out of the cargo holds for years now, and Boeing has now built an entire airplane around them.

You can't be serious in comparing thousands of pounds (in weight) of Li-ion batteries, densely packed on a pallet, possibly with dozens of pallets, in an are full of potential flammable stuff, to a SINGLE battery in a extremely controlled environment with no flammable material around it whatsoever.

Despite the fact that I still remain somewhat sceptical to some of the solutions Boeing has come up with (especially with respect to reliability and ETOPS>120), I have no problem whatsoever with stepping on a 787. I applaud Boeing for the relative fast return to air.

PW100



Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
User currently offlineDashTrash From United States of America, joined Aug 2006, 1565 posts, RR: 2
Reply 120, posted (1 year 8 months 1 day 8 hours ago) and read 6584 times:

Quoting rcair1 (Reply 118):
Quoting PW100 (Reply 119):

When I see "airline pilot" under your occupation, your opinions will hold a little more water. I say this fully understanding you may be well educated in these types of batteries, electrical systems, etc, and have much more knowledge in their operation than I do.

The difference is if one goes stupid, it's me, and people like me putting it back on the ground. No thank you, at least for the time being.


User currently offlinePW100 From Netherlands, joined Jan 2002, 2594 posts, RR: 16
Reply 121, posted (1 year 8 months 4 hours ago) and read 6355 times:

Quoting DashTrash (Reply 120):
When I see "airline pilot" under your occupation, your opinions will hold a little more water

Ah well. OK. I see. No use in further discussion then. I wonder why you bothered putting you view here in the first place.
  



Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
User currently offlinetugger From United States of America, joined Apr 2006, 5797 posts, RR: 10
Reply 122, posted (1 year 8 months 3 hours ago) and read 6308 times:

Quoting DashTrash (Reply 120):
When I see "airline pilot" under your occupation, your opinions will hold a little more water.

Why on earth would that be the case AT ALL in situations like this? That just seems silly.

Tugg



I don’t know that I am unafraid to be myself, but it is hard to be somebody else. -W. Shatner
User currently offlinercair1 From United States of America, joined Oct 2009, 1357 posts, RR: 52
Reply 123, posted (1 year 7 months 4 weeks 1 day 21 hours ago) and read 6175 times:
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Quoting PW100 (Reply 121):
Ah well. OK. I see. No use in further discussion then. I wonder why you bothered putting you view here in the first place.

Eeeyup - pretty much torpedoed any further posts from me... - well not really, but certainly in response to this item.   



rcair1
User currently offlinePW100 From Netherlands, joined Jan 2002, 2594 posts, RR: 16
Reply 124, posted (1 year 7 months 4 weeks 1 day 9 hours ago) and read 6047 times:

Quoting rcair1 (Reply 123):
pretty much torpedoed any further posts from me... - well not really

Sorry about that. We can't all be sitting in the front office . . .



Immigration officer: "What's the purpose of your visit to the USA?" Spotter: "Shooting airliners with my Canon!"
User currently offlinetortugamon From United States of America, joined Apr 2013, 3451 posts, RR: 11
Reply 125, posted (1 year 7 months 4 weeks 1 day 6 hours ago) and read 5937 times:

Quoting DashTrash (Reply 120):
When I see "airline pilot" under your occupation

As your occupation says furloughed pilot does that mean you are suspended from commenting too?

Just kidding DashTrash. If pilots' opinions were the only ones that mattered this board would be a lonely place.

tortugamon


User currently offlinelightsaber From United States of America, joined Jan 2005, 13551 posts, RR: 100
Reply 126, posted (1 year 7 months 4 weeks 1 day 5 hours ago) and read 5927 times:
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Quoting JoeCanuck (Reply 116):
I suspect Boeing is working on a less volatile battery chemistry in the long run, but this step certainly satisfies the safety aspect of the battery dangers.

I suspect that will be the long term answer. Implemented as a quiet 'battery life extension' program.

Quoting denverdanny (Reply 99):
Another perhaps poor analogy would be the Comet--sending that back out before discovering the cause and having another accident.

I can see what that could concern some. But the difference is Boeing has dramatically reduced the probability of a fault. Boeing (or their vendors) have fixed:
1. Fuel valve leakage (bad coatings)
2. Mis-wiring to the battery (drained battery and would age them prematurely).
3. Gentler battery charge cycle
4. Thermal isolation between battery cells (one run away cell no longer sets off all its neighbors)
5. Reduced battery charge volatage (less energy and less likely to have a battery fail)
6. Lower battery maximum discharge voltage (wears battery less and thus less likely to have a thermal over-run)
7. Containment of battery (including the vent).

The commet also had problems such as:
1. Stall on takeoff due to over-rotation (leading edge flaps help reduce that)
2. Early Comets had no control force feedback (could command too much actuation that could damage aircraft)
3. Belief that fire crashed the first fatigue loss. Completely wrong approach to solution (as you noted).


Aerospace engineering benefited tremendously from the lessons learned from the Comet. Such as design for variability and fatigue testing.

Quoting cornutt (Reply 111):
The battery contains a finite amount of energy; design a box that can contain that amount plus a design margin, add a mechanism to vent the gases, and the problem is literally boxed in.

Admittedly this does not satisfy the engineering mind, and it's less than ideal from an operational standpoint. But it's become apparent that root-cause answers are not going to be found easily. You can think of the containment solution as buying time.

Don't forget that the batteries are not being charged as much, are not being discharged as much, have better thermal isolation between batteries (one warm batter next to another won't set the other into thermal runaway), and the charging cycle is much gentler.

Its not just the box. The chance of a thermal runaway is *far* reduced. By about a factor of a thousand.

Quoting DashTrash (Reply 120):
When I see "airline pilot" under your occupation, your opinions will hold a little more water. I say this fully understanding you may be well educated in these types of batteries, electrical systems, etc, and have much more knowledge in their operation than I do.

The difference is if one goes stupid, it's me, and people like me putting it back on the ground. No thank you, at least for the time being.

   Thankfully there are teams of engineers who design aircraft far before it gets to a pilot. While pilots have skill and must take responsibility and should be respected for that, it is the engineers who know. Numerous times I've been able to tell pilots about a problem before they could tell (I came out of flight test engineering).

The era of the 'lone hero' is over. Its about systems and teams now. Boeing put together a team and solved the problem. It might not be the clear "A caused B," but much of engineering is probabilities now anyway. The probability of a problem was reduced and that is what is required.

I'm glad so much technology is being debugged in UAVs as there is less 'ego' to deal with. Develop the technology and then put it into production... I like talking with pilots to put in their input, but sometimes they suggest changes that the technical experts know won't work. Thankfully, aircraft are designed by good teams today.

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlinenomadd22 From United States of America, joined Feb 2008, 1903 posts, RR: 0
Reply 127, posted (1 year 7 months 4 weeks 1 day 4 hours ago) and read 5938 times:

Quoting lightsaber (Reply 126):

Don't forget that the batteries are not being charged as much, are not being discharged as much, have better thermal isolation between batteries (one warm batter next to another won't set the other into thermal runaway), and the charging cycle is much gentler.

Most of the life shortening problems I've found in lithium batteries stem from cramming that last 10% of the charge in. That's when the voltage and heat are highest and failures are the likeliest.



Andy Goetsch
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5478 posts, RR: 31
Reply 128, posted (1 year 7 months 4 weeks 1 day 2 hours ago) and read 5865 times:

Quoting nomadd22 (Reply 127):

It's easy enough to drop the charging cutoff threshold by a half a volt or so, as long as the batteries stay in the voltage range of the equipment they are supposed to run.

That would keep the top of the voltage range permanently out of reach, probably keeping things a bit more reliable and running cool.



What the...?
User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 129, posted (1 year 7 months 4 weeks 1 day 2 hours ago) and read 5866 times:

Quoting nomadd22 (Reply 127):

Most of the life shortening problems I've found in lithium batteries stem from cramming that last 10% of the charge in.

Now can you convince my wife that discharging the IPad to 1% or waiting tooth brush to stop running before you recharge will shorten the life expectancy of the battery? Or does this not apply to NiMH?

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinercair1 From United States of America, joined Oct 2009, 1357 posts, RR: 52
Reply 130, posted (1 year 7 months 4 weeks 1 day 2 hours ago) and read 5841 times:
AIRLINERS.NET CREW
CUSTOMER SERVICE & SUPPORT

Quoting PW100 (Reply 124):
Sorry about that. We can't all be sitting in the front office . . .

PW100 - I probably should have included DashTrash's quote instead of yours.
I was agreeing with you!



rcair1
User currently offlineJoeCanuck From Canada, joined Dec 2005, 5478 posts, RR: 31
Reply 131, posted (1 year 7 months 4 weeks 23 hours ago) and read 5754 times:

Quoting bikerthai (Reply 129):
Now can you convince my wife that discharging the IPad to 1% or waiting tooth brush to stop running before you recharge will shorten the life expectancy of the battery? Or does this not apply to NiMH?

Most Li-ion battery powered devices have built in voltage control. They automatically stop charging when the maximum voltage is reached and power cuts off at around 50%...sometimes even higher. Basically, there is still some voltage but not enough capacity left to do much.

Li-ion batteries don't suffer from the same 'memory' problems that NiCd's do, (and to a lesser degree, NiMh. There really isn't much advantage, if any, to fully drain your batteries before charging. In fact, full discharges can shorten the life of Li-ion batteries.

They do just fine, (and some electronics makers recommend), topping up lithium batteries whenever you get the chance, regardless of how much has been drained.

NiMh and NiCd's do better with the occasional full drain since they do get a partial charge memory...eventually, and are much less susceptible to overheating while charging.

So charge your ipad as often as you like and feel free to totally drain down the toothbrush occasionally.



What the...?
User currently offlineViscount724 From Switzerland, joined Oct 2006, 26021 posts, RR: 22
Reply 132, posted (1 year 7 months 4 weeks 23 hours ago) and read 5743 times:

Link to the Boeing service bulletin covering the 787 modifications. The parts kit alone costs about $285,000.
http://www.regulations.gov/contentSt...osition=attachment&contentType=pdf


User currently offlinezeke From Hong Kong, joined Dec 2006, 9240 posts, RR: 76
Reply 133, posted (1 year 7 months 4 weeks 21 hours ago) and read 5700 times:

Quoting twiga (Reply 83):

From a pure maths point of view, the probability of a specific event is actually zero. The reason being the aircraft as a system is a continuous random variable with an infinite number of outcomes, thus it does not have discrete countable outcomes. We measure (i.e. continuous distribution) rather than count (i.e. discrete distribution) aircraft in service events and reliability. We can come up with a probability for a range of measurements on a continuous distribution, however not a singular value as we have an infinite number of outcomes.

In a similar fashion I have seen people "abuse" stats when talking about engine reliability, engines are also a continuous distribution, decreasing/increasing the number of engines on an aircraft does not actually decrease/increase the rate of engine failures for an airframe. We never know when an engine will fail, as a system it has an infinite number of outcomes. If we did know when one would fail, it would be changed before hand and thus the discrete event never realised.

To put this in the battery context, having two batteries in the aircraft does not double the chance of failure, as both batteries may go their entire service life with failing. When a battery will fail is unknown.

I have seen nothing to suggest that these batteries were failing based upon a discrete event, the root cause is still unknown according to the Boeing SB. To testify to the NTSB regarding discrete events when looking at a continuous distribution of outcomes is illogical from a math point of view. Testing should be done to cover an continuous envelope of factors (normal and non-normal) to derive a continuous distribution of results.

Pure maths seems illogical at times, however this containment fix is actually mathematically sound. It should not factor into ETOPS at all.



We are addicted to our thoughts. We cannot change anything if we cannot change our thinking – Santosh Kalwar
User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 134, posted (1 year 7 months 4 weeks 4 hours ago) and read 5488 times:

Quoting DashTrash (Reply 120):
When I see "airline pilot" under your occupation, your opinions will hold a little more water. I say this fully understanding you may be well educated in these types of batteries, electrical systems, etc, and have much more knowledge in their operation than I do.

Since you don't trust the engineers and scientists and I guess that includes me, please check post #133 from a respected occupation other than the former mentioned, and (1) please translate for me, and (2) does it make you more comfortable in how safety statistics might be carried out in the future, and that the containment box is fine from a pure math perspective - with engineering and science not necessarily requisite as part of the solution?


User currently offlinetwiga From Canada, joined Mar 2013, 96 posts, RR: 0
Reply 135, posted (1 year 7 months 3 weeks 6 days 15 hours ago) and read 5267 times:

Quoting zeke (Reply 133):

From a pure maths point of view, the probability of a specific event is actually zero. The reason being the aircraft as a system is a continuous random variable with an infinite number of outcomes, thus it does not have discrete countable outcomes. We measure (i.e. continuous distribution) rather than count (i.e. discrete distribution) aircraft in service events and reliability. We can come up with a probability for a range of measurements on a continuous distribution, however not a singular value as we have an infinite number of outcomes.

The purpose for posting this in the first place was to gain some small understanding in how these metrics for safety might work. I qualified myself that I'm not an expert in this field and was seeking help in furthering this along. If you are capable and still interested please comment specifically on the issue and methodology described for the metrics of two engines out. Not here because its "getting off topic" and I have moved it to "Tech Ops" - Computing A/C Safety Metrics-Combined Redundancies. I have also commented on your post and clarified and refined the question so am looking for answers on the specifics.


User currently offlineAlpage From United Kingdom, joined Mar 2013, 42 posts, RR: 0
Reply 136, posted (1 year 7 months 2 weeks 1 day 8 hours ago) and read 4810 times:

When I said 1 month ago that the 787 fix was a band aid I was almost crucified here, "How dare you say this and that"..." How could you..is not band aid"..."be quiet..you know nothing".
Today we got this at the Financial Times:

"ANA suffers new Boeing Dreamliner problem"
http://www.ft.com/cms/s/0/36072f6a-b...27-00144feab7de.html#axzz2TTQFtZU5

All Nippon Airways on Thursday reported a problem with one of its 787 Dreamliners that has been undergoing test flights with a modified battery system.
ANA, the Japanese airline that is the largest operator of Boeing’s Dreamliner, said the incident involved damage to an electrical distribution panel but characterised the problem as “minor” and not related to the battery system. ......"

Yeah, right

[Edited 2013-05-16 09:33:48]

User currently onlinepar13del From Bahamas, joined Dec 2005, 7717 posts, RR: 8
Reply 137, posted (1 year 7 months 2 weeks 1 day 8 hours ago) and read 4743 times:

Quoting Alpage (Reply 136):

When I said 1 month ago that the 787 fix was a band aid I was almost crucified here,
Quoting Alpage (Reply 136):
said the incident involved damage to an electrical distribution panel but characterised the problem as “minor” and not related to the battery system. ......"

I cannot acces the article, but based on your post are you saying that the battery fix is a bandaid to a number of out-standing problems with the 787?
Seems to be the only correlation between your two comments, correct me if I'm reading wrong.


User currently offline817Dreamliiner From Montserrat, joined Jul 2008, 2612 posts, RR: 2
Reply 138, posted (1 year 7 months 2 weeks 1 day 8 hours ago) and read 4725 times:

Quoting Alpage (Reply 136):

Well, did the battery catch fire like before? If it didnt, then I dont see how you cant relate it to the fix...



Reality be Rent. Synapse, break! Vanishment, This World!
User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 139, posted (1 year 7 months 2 weeks 1 day 8 hours ago) and read 4713 times:

Quoting Alpage (Reply 136):
Yeah, right

As I understand it, the electrical panel has nothing to do with the battery.



Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlinelightsaber From United States of America, joined Jan 2005, 13551 posts, RR: 100
Reply 140, posted (1 year 7 months 2 weeks 1 day 8 hours ago) and read 4680 times:
Support Airliners.net - become a First Class Member!

Quoting nomadd22 (Reply 127):
Most of the life shortening problems I've found in lithium batteries stem from cramming that last 10% of the charge in. That's when the voltage and heat are highest and failures are the likeliest.

   But how deep the cycling is also effects wear. Both problems solved.

Quoting JoeCanuck (Reply 128):
That would keep the top of the voltage range permanently out of reach, probably keeping things a bit more reliable and running cool.

   Plus the charging is slower (less heat). All parts of what cause a Li battery failure have been addressed.

Quoting Viscount724 (Reply 132):

Link to the Boeing service bulletin covering the 787 modifications. The parts kit alone costs about $285,000.

Cheaper than the grounding costs...  
Quoting Alpage (Reply 136):
Yeah, right

All aircraft have problems. I bet A330s have issues in electrical distribution (I know 744s do, albeit rarely.) You just want to be skeptical, don't you?

We'll see the production rate ramp up soon. Let's calibrate the improvement! The 787 had at least three known issues fixed during the downtime.

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently online7BOEING7 From United States of America, joined Oct 2012, 1772 posts, RR: 16
Reply 141, posted (1 year 7 months 2 weeks 1 day 7 hours ago) and read 4683 times:

Quoting Alpage (Reply 136):
All Nippon Airways on Thursday reported a problem with one of its 787 Dreamliners that has been undergoing test flights with a modified battery system.ANA, the Japanese airline that is the largest operator of Boeing’s Dreamliner, said the incident involved damage to an electrical distribution panel but characterised the problem as “minor” and not related to the battery system. ......"Yeah, right

From Reuters:

"Engineers found discoloration on a connection on an electrical panel following a flight from Tokyo's Haneda Airport to Sapporo on Japan's northern island of Hokkaido on May 4, a spokesman for ANA said.

The panel, which was not part of the jetliners' battery system, was changed and the plane returned to Tokyo. ANA blamed a loose nut for the cause of the problem, which it said did not compromise the safety of the aircraft."


http://uk.reuters.com/article/2013/0...n-dreamliner-idUKBRE94F0C220130516


I guess you're right -- The sky is falling, the sky is falling!!!!


User currently offlineAlpage From United Kingdom, joined Mar 2013, 42 posts, RR: 0
Reply 142, posted (1 year 7 months 2 weeks 1 day 4 hours ago) and read 4551 times:

"the electrical panel has nothing to do with the battery". Sounds really weird.

User currently offlinesankaps From United States of America, joined Jan 2008, 2255 posts, RR: 2
Reply 143, posted (1 year 7 months 2 weeks 1 day 4 hours ago) and read 4543 times:

Quoting Alpage (Reply 142):
"the electrical panel has nothing to do with the battery". Sounds really weird.

So according to you, if a light bulb fails in your car, or a dashboard meter malfunctions, or the radio goes on the blink, or wiring in your dashboard frays and discolors, it must all be caused by the car's battery?


User currently onlinePITingres From United States of America, joined Dec 2007, 1163 posts, RR: 13
Reply 144, posted (1 year 7 months 2 weeks 1 day 4 hours ago) and read 4481 times:

Quoting Alpage (Reply 142):
"the electrical panel has nothing to do with the battery". Sounds really weird.

Only if you insist on visualizing the EE bay as a single large glowing ball of light.  

Seriously? The battery is its own box, not even mounted on the panel, and you think that a loose nut on a panel somehow has something to do with the battery? I think you are reaching.



Fly, you fools! Fly!
User currently onlinePITingres From United States of America, joined Dec 2007, 1163 posts, RR: 13
Reply 145, posted (1 year 7 months 2 weeks 1 day 1 hour ago) and read 4339 times:

Let's suppose that I have problems with my basement door, which is wood. The latch doesn't engage reliably because the door or jamb has sagged. I finally replace the door.

Two weeks later, when I go to open my Ikea bedroom dresser drawer, the drawer pull falls off because when I put it together I didn't tighten the hardware properly.

The basement door must still be faulty! My door repair was shoddy! After all, they are both wooden devices.

 

My invented scenario makes about as much sense as worrying about the battery fix because of a loose nut on a power panel. If you want to worry about the electrical system as a whole, I think it's irrational, but fine, be my guest. But don't tell us that the battery fix is suspect because of an unrelated loose nut, please.



Fly, you fools! Fly!
User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 146, posted (1 year 7 months 2 weeks 12 hours ago) and read 4023 times:

It is so funny to me that all this talk about failed battery has overtaken the skepticism about a composite airframe (in a crash) as the bane of the 787 existence.

Perhaps this is Boeing's great PR move to divert attention from the inherent danger of a composite airplane . . .

        

Triple sarcasm intended . . .

bt



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinelightsaber From United States of America, joined Jan 2005, 13551 posts, RR: 100
Reply 147, posted (1 year 7 months 1 week 6 days 3 hours ago) and read 3797 times:
Support Airliners.net - become a First Class Member!

Quoting bikerthai (Reply 146):
Perhaps this is Boeing's great PR move to divert attention from the inherent danger of a composite airplane . . .

What danger? Have you ever seen what happens when aluminum catches fire? It is far more energetic a fuel than CFRP. Remember the Sheffield. Once aluminum starts burning, only foam will stop it.

IMHO, CFRP has long been the way to go with airframes. I now accept for narrowbodies that the "cigar" will still be beer can. But a new wing? The big aerospace companies are losing the knowledge on how to build aluminum wings as the teams have been designing CFRP for so long due to its many advantages.

Or do you like the corrosion problems the A320 wings are having?

The only 'issue' with CFRP is that is coefficient of thermal expansion is compatible with aluminum (e.g., A380 wings). The easy solution is to make the whole plane out of CRFP (or use titanium).

Get used to CFRP. Its a superior material for wings than aluminum by far. Now that we're progressing towards the next *two* generations of laminar flow wings, I do not see how they can be made out of aluminum without a severe weight penalty.

Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
User currently offlineStitch From United States of America, joined Jul 2005, 31437 posts, RR: 85
Reply 148, posted (1 year 7 months 1 week 6 days 1 hour ago) and read 3704 times:
Support Airliners.net - become a First Class Member!

Quoting lightsaber (Reply 147):
What danger?
Quoting bikerthai (Reply 146):
Triple sarcasm intended . . .

He was being facetious, sir.  


User currently offlineKarelXWB From Netherlands, joined Jul 2012, 13215 posts, RR: 36
Reply 149, posted (1 year 7 months 1 week 4 days 4 hours ago) and read 3467 times:

Here is a picture showing the new battery exhaust:




Only two things are infinite, the universe and human stupidity. And I'm not sure about the universe.
User currently offlinebikerthai From United States of America, joined Apr 2010, 2197 posts, RR: 4
Reply 150, posted (1 year 7 months 1 week 3 days 12 hours ago) and read 3283 times:

Quoting Stitch (Reply 148):
He was being facetious, sir.

Yep, they didn't have a smiley for smart a$$.

bt 



Intelligent seeks knowledge. Enlightened seeks wisdom.
User currently offlinelightsaber From United States of America, joined Jan 2005, 13551 posts, RR: 100
Reply 151, posted (1 year 7 months 1 week 3 days 12 hours ago) and read 3260 times:
Support Airliners.net - become a First Class Member!

Quoting Stitch (Reply 148):
He was being facetious, sir.

Touche'


Lightsaber



Societies that achieve a critical mass of ideas achieve self sustaining growth; others stagnate.
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