Most of the batteries were returned because they had run down so far that a low-voltage cutout was activated.
At that stage, the batteries, which cost about $16,000 each, are essentially dead and cannot be recharged.
waynefromnscanada wrote: »
""This is a clear indication that Boeing has identified the problem and may even have found a solution," he said.
"The logical step is to conduct test flights and see if the solution does work."http://www.bbc.co.uk/news/business-21332256
RCinFLA wrote: »
I have read a few contradicting reports. Still sounds like some political fingerpointing and counter fingerpointing going on. Japan ministry says the batteries are not the root cause (Japan sources the batteries). They seem to imply the charge controller / monitor (French built) is the root cause. ANA 787's have changed out a large number of batteries due to issues since they have been using 787's which should have been an early warning sign.
solar_dave wrote: »
I heard on CNBC that the French made battery cables were suspect.
ggunn wrote: »
techntrek wrote: »
...which were French fried.
RCinFLA wrote: »
The report today is the battery certification process and failure containment box did not consider that one bad cell could set off a chain reaction by direct heating other batteries, in turn setting them off. The containment box could not handle all the cells in thermal runaway.
Title: Risk analysis of the space shuttle: pre-challenger prediction of failure
Author(s): Siddhartha R. Dalal , Edward B. Fowlkes and Bruce Hoadley
Source: Journal of the American Statistical Association. 84.408 (Dec. 1989): p945. From General OneFile.
Document Type: ReportFull Text: COPYRIGHT 1989 American Statistical Association http://www.amstat.org/
The Rogers Commission report on the space shuttle Challenger accident concluded that the accident was caused by a combustion gas leak through a joint in one of the booster rockets, which was sealed by a device called an O-ring. The commission further concluded that O-rings do not seal properly at low temperatures. In this article, data from the 23 preaccident launches of the space shuttle is used to predict O-ring performance under the Challenger launch conditions and relate it to the catastrophic failure of the shuttle. Analyses via binomial and binary logistic regression show that there is strong statistical evidence of a temperature effect on incidents of O-ring thermal distress. In addition, a probabilistic risk assessment at 31 [degrees]F, the temperature at which Challenger was launched, yields at least a 13% probability of catastrophic field-joint O-ring failure. Postponement to 60 [degrees]F would have reduced the probability to at least 2%. To assess uncertainty in estimates and for any future prediction under the Challenger scenario, a postanalysis prior distribution of the probability of a catastrophic failure is derived. The mean and median for this distribution for 31 [degrees]F are at least .16 and .13, and for 60 [degrees]F they are at least .004 and .02, respectively. The analysis of this article demonstrates that statistical science can play an important role in the space-shuttle risk-management process.
KEY WORDS: Catastrophic failure; Data analysis; O-rings; Probability risk assessment; Statistical science.
Cariboocoot wrote: »
And they didn't think of that to begin with?