Without Answers, 787 Probe Could Stretch Into 'Weeks'

The bad news keeps coming for Boeing, whose 787 Dreamliner fleet remains grounded—US investigators still don't know what caused the battery fire in a Jan. 7 fire in Boston, reports Reuters. The National Transportation Safety Board says it has found a series of "symptoms" in the battery, but are nowhere near knowing the underlying cause. The NTSB chair would not say how long the investigation might take, but a former NTSB chair predicts, "It's going to take them longer. Weeks, not days."

Investigators are concerned that back-up protections designed to prevent a "thermal runaway"—a chain reaction causing the battery to overheat—did not work, reports the Los Angeles Times. "There are multiple systems to protect against a battery event like this," says the current NTSB chair. "Those systems did not work as intended." (More National Transportation Safety Board stories.)