FAA Grounds 787s
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ExSp33db1rd: The Yuasa ones involved were confirmed by NTSB as Li-ion cobalt. But yes it sounds like the BOS fire brigade didn't so much put the fire out as keep the surrounding area cool until it burnt out.
Does anyone know what Airbus plan to use on the A350? The safer, but lower performance Li-ion-manganese or the cobalt?
Does anyone know what Airbus plan to use on the A350? The safer, but lower performance Li-ion-manganese or the cobalt?
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I ask myself why have Boeing gone with this technology?
My suggestion is because the a/c is all electric then there are ultimate failure situations where high energy is needed. On every a/c I have flown before the brakes for example have a brake accumulator. The brakes on this a/c are electric, so the backup has to be the same. A high energy battery?
My suggestion is because the a/c is all electric then there are ultimate failure situations where high energy is needed. On every a/c I have flown before the brakes for example have a brake accumulator. The brakes on this a/c are electric, so the backup has to be the same. A high energy battery?
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You are not the only one who wonders why Boeing took that risk for the benefit of a few kilogramms....
It's easy for us who have the benefit of 20/20 hindsight to know which kilograms might better not have been saved. Airbus has also planned to use lithium batteries on the A350, and they were not highly controversial before the recent incidents.
It's a bit ironic that a battery which is only there as a redundant contingency measure, to add to safety, now instead causes trouble, but I applaud Boeing for being ambitious- and I applaud the Japanese carriers for temporarily grounding their planes, and the FAA for issuing an AD. Every now and then there will be idiosyncratic teething problems with new technology, but no one has been physically harmed, aviation safety is better than ever, and I'm confident the issues will be resolved. Technology will continue to evolve.
Last edited by deptrai; 29th Jan 2013 at 10:14.
deptrai:
...and so do I. It's a very advanced design from the info available.
There's no progress without change and as technology and engineering solutions
become ever more complex, so will the risks multiply. There's no free lunch
and engineering will always be a devil's compromise between cost, reliability
and performance.
The A340 fbw design is still controversial in some areas, even years after
introduction, but let the record speak for itself...
It's a bit ironic that a battery which is only there as a redundant
contingency measure, to add to safety, now instead causes trouble, but I
applaud Boeing for being ambitiousbut I applaud Boeing for being
ambitious....
contingency measure, to add to safety, now instead causes trouble, but I
applaud Boeing for being ambitiousbut I applaud Boeing for being
ambitious....
There's no progress without change and as technology and engineering solutions
become ever more complex, so will the risks multiply. There's no free lunch
and engineering will always be a devil's compromise between cost, reliability
and performance.
The A340 fbw design is still controversial in some areas, even years after
introduction, but let the record speak for itself...
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ExSp33db1rd,
Just to clarify, the talk is about Lithium-Manganese, as an alternative to -Cobalt, not Magnesium. Totally different stuff.
Technically both types use oxide, and not elementary metallic Cobalt or Manganese.
Yes, Magnesium can burn very hot, and continues burning under water and under CO2, but Manganese is quite different.
[...] I've read a couple of posts that suggest that Boeing changed to Lithium Magnesium -so that's alright then, I'd rather be on board a 787 suffering a serious Lithium Magnesium fire than a Lithium Cobalt fire. Much more comforting on an ETOPS sector.
Technically both types use oxide, and not elementary metallic Cobalt or Manganese.
Yes, Magnesium can burn very hot, and continues burning under water and under CO2, but Manganese is quite different.
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Lithium-Manganese, vs Cobalt vs Iron
I would expet the final design to switch to LFP these are the very saftest Li chemistry. Much better weight then Pb or Nicad long cycle life. Slightly more weight than most other Li chemistry 
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bsieker (bernd).....
Thanks for clearing that up. It is nice to be able to share the "uninformed" yoke of criticism....
The irony is instructive, for there must be a balance among progress, risk, innovation, and SAFETY.
It is by no mistake that our Supreme Court has labelled a CORPORATION as having the attributes of an "individual".
EGO, GREED, AGGRESSION, etc. They belong in the Boardroom, not on the floor, or in the "discussions" between Airframer and Regulator.
Every bit as important as the technical, is the procedural.....
Corporations invest other people's money, to put at risk other people's lives.....
And collect the benefits therefrom. Without imbalance, there is no progress.
Without Delta, there is no velocity. Herein is a tutorial for those who wish to see it.
I am a betting man. And my money is on the FAA.
Hell hath no fury like a bureaucrat, shamed...
Relative to ops, and maintenance. This area was presented early on, and got some criticism.... The airframer has an obligation to support its product in the field. Whether Battery, or Controls system, "sink or swim" won't 'Fly'.
Thanks for clearing that up. It is nice to be able to share the "uninformed" yoke of criticism....
The irony is instructive, for there must be a balance among progress, risk, innovation, and SAFETY.
It is by no mistake that our Supreme Court has labelled a CORPORATION as having the attributes of an "individual".
EGO, GREED, AGGRESSION, etc. They belong in the Boardroom, not on the floor, or in the "discussions" between Airframer and Regulator.
Every bit as important as the technical, is the procedural.....
Corporations invest other people's money, to put at risk other people's lives.....
And collect the benefits therefrom. Without imbalance, there is no progress.
Without Delta, there is no velocity. Herein is a tutorial for those who wish to see it.
I am a betting man. And my money is on the FAA.
Hell hath no fury like a bureaucrat, shamed...
Relative to ops, and maintenance. This area was presented early on, and got some criticism.... The airframer has an obligation to support its product in the field. Whether Battery, or Controls system, "sink or swim" won't 'Fly'.
Last edited by Lyman; 29th Jan 2013 at 14:18.
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RR_NDB makes a thought-provoking point. The life-cycle and failure rate of Li batteries is very much determined by environment and pattern of usage. For instance they tend to degrade much faster if stored fully charged and/or at high temperature.
When the technology is relatively new, the application/deployment environment novel and the associated battery charge/discharge cycling pattern possibly rather unusual, it leaves open the possibility of some unrecognised factor in physics/chemistry, as there was when metal fatigue started downing early passenger jets.
When the technology is relatively new, the application/deployment environment novel and the associated battery charge/discharge cycling pattern possibly rather unusual, it leaves open the possibility of some unrecognised factor in physics/chemistry, as there was when metal fatigue started downing early passenger jets.
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I believe it was the superior reserve power capacity of the Lithium battery rather than weight which led Boeing to their battery choice.
This all electric a/c is fine whilst in the air, even with say a double engine failure, as windmilling engines, RAT, an APU (if it starts) will provide sufficient electrics to power high load items like flying controls.
On the ground its a different matter.
It is interesting the A380 has a very high pressure hydraulic system 5000psi? in order to provide the necessary power for high load items.
Boeing decided electric cables were lighter? & simpler to transfer high load items. However unlike hydraulics which tend to leak in failure mode, electric cables if overloaded tend to catch fire.
This all electric a/c is fine whilst in the air, even with say a double engine failure, as windmilling engines, RAT, an APU (if it starts) will provide sufficient electrics to power high load items like flying controls.
On the ground its a different matter.
It is interesting the A380 has a very high pressure hydraulic system 5000psi? in order to provide the necessary power for high load items.
Boeing decided electric cables were lighter? & simpler to transfer high load items. However unlike hydraulics which tend to leak in failure mode, electric cables if overloaded tend to catch fire.
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Last edited by RR_NDB; 29th Jan 2013 at 20:03.
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Classic TESTABILITY issue
Hi,
How? Automatically? Who manages?
I hope the batteries (required to be able to deliver power when necessary) that must be kept charged sometimes are tested to show itīs "readiness".
But, this is a TESTABILITY ISSUE (frequent when you must have REDUNDANT items kept "offline")
How? Automatically? Who manages?
I hope the batteries (required to be able to deliver power when necessary) that must be kept charged sometimes are tested to show itīs "readiness".
But, this is a TESTABILITY ISSUE (frequent when you must have REDUNDANT items kept "offline")
Last edited by RR_NDB; 29th Jan 2013 at 19:57. Reason: + link
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Sound warning to Boeing
Hi
Paradox:
You put "redundant for contingency" * items, keep both "ready" at full capacity, OFFLINE, and they fail twice in few days.
Murphy law put this to Boeing and US in a critical moment.
Concerning.
Paradox:
You put "redundant for contingency" * items, keep both "ready" at full capacity, OFFLINE, and they fail twice in few days.
Murphy law put this to Boeing and US in a critical moment.
Concerning.
Last edited by RR_NDB; 29th Jan 2013 at 20:02.
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A partial recap for late commers...
When they designed the 787 I think Lithuim Cobalt was the most proven of the Lithium cell technologies available.
Since then some/many other users have switched to Lithium Manganese for because of possible concerns over the safety of Lithium Cobalt.
It's possible Boeing were/are considered changing to Lithium Manganese but don't appear to have done so yet.
When they designed the 787 I think Lithuim Cobalt was the most proven of the Lithium cell technologies available.
Since then some/many other users have switched to Lithium Manganese for because of possible concerns over the safety of Lithium Cobalt.
It's possible Boeing were/are considered changing to Lithium Manganese but don't appear to have done so yet.
Last edited by cwatters; 29th Jan 2013 at 16:22.
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cwatters
Lyman: (post #426)
It was Boeing's intention to shift the batteries to Manganese for the delivered 787, evidently they changed their mind. That would be an interesting discussion.
As I recall, the first Limn was to be in the ANA that had the problem....
Lyman: (post #426)
It was Boeing's intention to shift the batteries to Manganese for the delivered 787, evidently they changed their mind. That would be an interesting discussion.
As I recall, the first Limn was to be in the ANA that had the problem....
Last edited by Lyman; 29th Jan 2013 at 16:59.
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Does anyone know what Airbus plan to use on the A350? The safer, but lower performance Li-ion-manganese or the cobalt?
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For all of the battery affraied ones here: Currently there is no hint that the battery itself failed. The investigations are more concentrated to find the malfunction within the surrounding electrical system. We should stop the discussion which bat ist more dangerous than others. 
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Taunusflyer
We should stop the discussion which bat ist more dangerous than others