FAA Grounds 787s
A steel box is all well and good but surely a safety cased based on containing an energetic fire is only acceptable against risk up to some probability of occurance. If you don't know what the probability of occurrence is, how do you make the case?
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In usual fashion the beancounters won out, the aircraft was pushed out the door so Boeing could book some revenue, and now the mess needs to be mopped up, and will end up costing far more to put right, than it would have if done properly in the first place.
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fire is only acceptable against risk up to some probability of occurance
As I recall, there was at least 1 engineer (who was sacked by Boeing)
Ut Sementem Feeceris
Who gives a **** about 1 engineer, there could be even 100 engineers, the extent of testing is strictly determined and controlled by the certification agency.
As for the oxygen thing, I thought the cells generated their own during runaway so it's a mute point - still the battery is self destructing inside a nice box so it's ok.....
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"Also it is the FAA that decides what certification process is, not the NTSB"
Many years ago the Sunday Times Insight team wrote abook about the problems with the DC10, ultimately leading to the Paris crash (Destination Disaster). In it, the FAA is described as "fat, dumb and happy". It would seem that not a lot has changed.
Many years ago the Sunday Times Insight team wrote abook about the problems with the DC10, ultimately leading to the Paris crash (Destination Disaster). In it, the FAA is described as "fat, dumb and happy". It would seem that not a lot has changed.
In it, the FAA is described as "fat, dumb and happy". It would seem that not a lot has changed.
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In it, the FAA is described as "fat, dumb and happy". It would seem that not a lot has changed.
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fenland I agree with you My dealings with the FAA have ALWAYS been conducted with extreme professionalism can't say a bad word about them TBH same with the CAA and EASA.
Well, the Japan Transport Safety Board has come out with their draft report that suggests extreme cold as a contributing factor to battery deterioration.
Battery problems plaguing Boeing's B787 Dreamliner may be tied to extreme cold - AJW by The Asahi Shimbun
Battery problems plaguing Boeing's B787 Dreamliner may be tied to extreme cold - AJW by The Asahi Shimbun
I don't think the forward and aft equipment bays get that cold. Its pressurized and conditioned air in there. Probably close to the temps one would expect in the cargo spaces.
NHK had a comment on this yesterday. They said that it gets even colder in Europe, but similar problems had not arisen there, so the Japan Transport Safety Board is still not 100% sure they will finalize the report like this.
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Reports elsewhere say that charging lithium cells when they are too cold causes lithium plating which can cause short circuits and failure. Cold for a consumer grade lithium is 0-5C. No idea what aircraft grade batteries consider cold to be.
I'm sure the tech is different but I think Tesla cars do different things when the battery is cold. I believe they have a battery heater to keep it within range and I think you loose regenerative braking until the battery is warm enough.
Edit:
http://batteryuniversity.com/learn/a...the_boeing_787
I'm sure the tech is different but I think Tesla cars do different things when the battery is cold. I believe they have a battery heater to keep it within range and I think you loose regenerative braking until the battery is warm enough.
Edit:
http://batteryuniversity.com/learn/a...the_boeing_787
Li-ion should not be charged below freezing. Fast-charging is only permissible from 5 to 45°C (41 to 113°F). Although Li-ion appears to be charging, a plating of metallic lithium can occur on the anode during cold temperature charging. Batteries affected by cold charging are more vulnerable to failure if exposed to vibration or other stressful conditions. (Some Li-ion cells are made to charge down to –10°C (14°F) but at a reduced rate.)
FAA have ALWAYS been conducted with extreme professionalism
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Are the lack of current B787 reports on Rumours and News section of pprune to indicate that the manufacturer and industry have now got to grips with the initial teething problems?
Al Jazeera TV has been advertising Broken Dreams, an upcoming documentary on the ups and downs of the Dreamliner. Very brave.
I suspect that some in the US will not be happy with such exposure.
I suspect that some in the US will not be happy with such exposure.
If operators start basing their purchase decisions on TV Network hit pieces put together by people who barely know the difference between an airplane and a hair dryer, then the whole industry had better care.
BTW, the part about TV networks isn't particularly aimed at Al Jazeera - few of the other networks are any better.
BTW, the part about TV networks isn't particularly aimed at Al Jazeera - few of the other networks are any better.