Japan’s 787 probe finds battery short-circuiting

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 both 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 the Japanese investigators show severe 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 787s in operation are grounded as regulators and Boeing investigate the problem. The Japanese probe is focusing on flight data records and on the charger and other electrical systems connected to the damaged battery.

Lithium ion batteries are more susceptible to catching fire when they overheat or to short-circuit than other types of batteries. Boeing built in safeguards to gain safety certification for use of the relatively light and powerful batteries to power various electrical systems on the 787, the world’s first airliner made mostly from lightweight composite materials.

Investigators earlier said they found no evidence of quality problems with production of the 787’s batteries by Kyoto, Japan-based, GS Yuasa.

More in Herald Business Journal

Tesla rolls out the design for its 500-mile electric big rig

The truck will have an Autopilot system, which can maintain a set speed and slow down in traffic.

How Airbus’s A380 deal with Emirates evaporated in Dubai

It came down to concern by Emirates that Airbus might shut down the jumbo program.

Equipment rental and sales business H&E opens Mukilteo shop

Company hopes to capitalize on construction occuring in northwest Washington.

New Chick-fil-A draws dozens of campers in Bothell

A second restaurant of the popular chain is opening on Thursday.

Tulalip Resort Casino to feature locally grown hazelnuts

The resort wanted to put a focus on meals created with the nut.

Alderwood Water general manager named president of state association

Alderwood Water & Wastewater District General Manager Jeff Clarke has been installed… Continue reading

Boeing earns top marks for LGBTQ workplace policies

Boeing was one of 609 businesses nationwide to earn a 100-point score… Continue reading

Aerospace workers adjust to changing industry

The number of Boeing workers dropped almost 10 percent since last year

Derided by critics, trickle-down economics gets another try

The concept — also known as supply-side economics — has frequently drawn ridicule.

Most Read