Christine Negroni riffs on aviation and travel and whatever else inspires her to put words to page.
Friday, March 8, 2013
Ahhh, Boeing, About Those Hours of Battery Testing
A curious thing emerges from the five hundred plus page report issued by the National Transportation Safety Board on Thursday, as I reported here for APEX Editors Blog. Despite all its talk about thoroughly, exhaustively, comprehensively testing the lithium ion batteries used on the Dreamliner, Boeing and its subcontractors failed repeatedly to gauge how separate components of the battery system would work together.
Securaplane, producers of the charger for the 787 battery, tested its product. Thales, which was contracted by Boeing to design and create the battery system, tested some components. But when it came time to put it all together and run tests on the whole shebang, Thales failed to examine what was going on inside the eight individual cells that make up the Dreamliner's battery according to the NTSB report.
"Securaplane is not off the hook, Thales is not off the hook," I was told by a source connected to the investigation who asked not to be identified. Neither, apparently, did Boeing or the Federal Aviation Administration, which is obligated to review - before approving - material submitted by a plane maker seeking certification.
This is one of many curious findings in a volume of reports put out by the safety board. Another verrrrrry interesting section deals with how the battery on the Japan Airlines 787 acted when it started smoking at the gate at Boston's Logan Airport. Domenic Gates of the Seattle Times gives a overview you can read here.
The NTSB's various working groups' have shoveled into a great big pile, a blizzard of documents, calculations, schematics and diagrams from Boeing all predicting how the Dreamliner would act in the "unlikely" case of a battery problem. Now all that paperwork is starting to look like a snow job because what actually happened on January 7th was a heap of a surprise.
For starters there's the fire; the catastrophic circumstance Boeing claimed would not happen more often than one in a billion flight hours but did indeed occur on a plane with 169 flight hours. Then there's the device designed to vent smoke over board that did not work, because the vent is powered by the APU which is powered by, you guessed it, the battery which stopped working sometime after it started smoking.
Given these errors in assessing what might happen on Boeing's newest airliner, NTSB investigators are said to be taking a look at some of the other issues raised by experts since the ignominious grounding of the fleet on January 16th.
For example, MIT materials professor Don Sadowayhas expressed concern about the placement of the four battery management system circuit panels so close to the battery cells. "If you have thermal runway, you fry the board," he told me. Certainly photographs distributed by the investigators with the Japan Transport Safety Bureau, indicate Sadoway may be correct. The panels' location inside the box is one of many, many aspects the NTSB is reviewing.
From small details like panel placement, to the high altitude review of whether the plane got off the ground with a critical safety issue embedded it its power design, a five hundred page report appears to be just the start.