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n Feb. 7, the National Transportation Safety Board (NTSB) said it concluded “after an exhaustive exami- nation” that a battery fire in a Boeing (Chicago) 787 Dreamliner “pointed to an initiating event in a single cell.” That Jan. 7 fire, along with another incident involving a 787 battery on Jan. 16, contributed to regulators’ decision to ground the plane model and begin an investigation. The NTSB has been providing in-depth updates on its investigation at http://tinyurl. com/mfgengmedia787. In its most recent update before press time, the NTSB said a single battery “cell showed multiple signs of short circuiting, leading to a thermal runaway condi- tion, which then cascaded to other cells. Charred battery components indicated that the temperature inside the battery case exceeded 500 degrees Farenheit.” As investigators work to find the cause of the ini- tiating short circuit, they have already ruled out both mechanical impact damage
battery, and the possibility of defects introduced during the manufacturing process.
As of press time, the 787 remained grounded. The FAA took the rare and historic step of grounding the 787 on Jan. 16 after the incidents involving the lithium- ion batteries.
In the first, an empty 787 owned by Japan Airlines (JAL) experienced a battery fire on Jan. 7 while parked at Boston’s
NTSB Materials Engineer Matt Fox examines the casing from the battery involved in the JAL Boeing 787 fire incident in Boston.
to the battery and external short circuiting. Signs of deforma- tion and electrical arcing on the battery case occurred as a
Logan International Airport. Nine days later, on Jan. 16, a 787 operated by All Nippon Airlines (ANA) was forced to make an
Before further flight, operators of US-registered, Boeing 787 aircraft must demonstrate to the Federal Aviation Administration (FAA) that the batteries are safe.
result of the battery malfunction and were not related to its cause, NTSB concluded. NTSB Chairman Deborah A.P. Hersman said that potential causes of the initiating short circuit currently being evaluated include battery charging, the design and construction of the
emergency landing at Takamatsu Airport on Shikoku Island after the flight crew received a computer warning that there was smoke inside one of the electrical compartments. The passenger and crew were evacuated using the plane’s emer- gency slides.