Boeing Battery-Fire Probe Gets Tricky

Looks like Boeing has a bigger headache than it expected, the Wall Street Journal reports. The National Transportation Safety Board released a statement yesterday saying that the first 787-airliner fire this month was caused by a battery that "did not exceed its designed voltage"—while Japanese investigators looking at a second lithium-ion mishap say the battery may have been overcharged. So Boeing, its fleet grounded for five days now, is watching the investigation grow in different directions.

The safety board said it is looking inside the battery from the Japan Airlines flight in Boston on Jan. 7. Scans of the battery may show whether a manufacturing flaw or internal defect caused the battery to overheat, but they're also considering external factors like wiring and circuit boards. Seems like the NTSB is making an extra effort, updating its statement after midnight on day three of a four-day holiday, and sending Boeing parts from the burned plane to help them work on possible safeguards. (More Boeing stories.)