Boeing probe uncovers battery flaw

Boeing probe uncovers battery flaw
Finding was similar to incident in Boston

Feb. 5, 2013 8:46 PM,




This photo shows the distorted main lithium-ion battery, left, and an undamaged auxiliary battery of the All Nippon Airways' Boeing 787 that made an emergency landing Jan.16. / Japan Transport Safety Board/AP file

Battery maker GS Yuasa said Tuesday that its April-December net profit fell 3.6 percent to $59.6 million from a year earlier, as demand for batteries lagged due to sluggish demand in Japan and overseas. 

The company has struggled to turn its lithium ion business to profitability. In April-December its lithium ion business posted a $78.2 million loss.

TOKYO — An investigation into a lithium ion battery that overheated on a Boeing 787 flight in Japan last month found evidence of the same type of “thermal runaway” seen in a similar incident in Boston, officials said Tuesday.

The Japan Transportation Safety Board said that CAT scans and other analysis found damage to all eight cells in the battery that overheated on the All Nippon Airways 787 on Jan. 16, which prompted an emergency landing and probes by U.S. and Japanese aviation safety regulators.

They also found signs of short-circuiting and “thermal runaway,” a chemical reaction in which rising temperature causes progressively hotter temperatures. U.S. investigators found similar evidence in the battery that caught fire last month on a Japan Airlines 787 parked in Boston.

Photos distributed by Japanese investigators show charring of six of the eight cells in the ANA 787’s battery and a frayed and broken earthing wire — meant to minimize the risk of electric shock.

All 50 Boeing 787 Dreamliners in operation are grounded as regulators and Boeing investigate the issue. The Japanese probe is focusing on flight data records and on the charger and other electrical systems connected to the damaged battery.