TOKYO (AP) — The main battery beneath the cockpit of the Boeing 787 forced to make an emergency landing in Japan was swollen from overheating, a safety official said Thursday, as aviation regulators worldwide joined the U.S. and Japan in grounding the technologically advanced aircraft because of fire risk.
U.S. officials, and a Boeing engineer, are due in Japan on Friday to assist with Japan's investigation into the All Nippon Airways 787 that landed in western Japan after a cockpit message showed battery problems and a burning smell was detected in the cockpit and cabin.
The battery in an electrical room beneath the cockpit was swollen and had leaked electrolyte, safety inspector Hideyo Kosugi said on Japanese broadcaster NHK. Investigators found burn marks around the battery, though it was not thought to have caught fire. Kosugi also said the electrolyte liquid leaked through the electrical room floor to the outside of the aircraft, Kyodo news agency reported.
The 787, known as the Dreamliner, is Boeing's newest jet, and the company is counting heavily on its success. Since its launch after delays of more than three years, the plane has been plagued by a series of problems including a battery fire and fuel leaks.
GS Yuasa Corp., the maker of the lithium ion batteries used in the 787s, said it was helping with the investigation but that the cause of the problem was unclear.
"We still don't know if the problem is with the battery, the power source or the electronics system," said Yasushi Yamamoto, a spokesman the company which is based in Kyoto, Japan. "The cause of the problem is not clear," he said. Thales, which makes the battery charging system, has not commented so far.
Air India's decision Thursday to ground its fleet of six Boeing 787, under orders from Indian aviation authorities, and similar decisions in Europe and Qatar mean that nearly all of the 50 Dreamliners in use around the world are now out of action.
Japan's ANA, which has 17 of the 787s and Japan Airlines, which has seven, voluntarily halted flights Wednesday after the emergency landing but aviation authorities have now made the grounding an official directive.
In Washington, the Federal Aviation Administration also required U.S. carriers to stop flying 787s until the batteries are demonstrated to be safe. United Airlines has six of the jets and is the only U.S. carrier flying the model. Aviation authorities in other countries usually follow the lead of the country where the manufacturer is based.
Yasuo Ishii, an official with the aviation safety division of Japan's transport ministry, said Japan Airlines and ANA had been directed not to fly their 787s until questions over safety of the aircraft are resolved.
The 787 relies more than any other modern airliner on electrical signals to help power nearly everything the plane does. It's also the first Boeing plane to use rechargeable lithium ion batteries for its main electrical system. The batteries charge faster and can be molded to space-saving shapes compared to other airplane batteries, allowing the use of lightweight composite materials instead of aluminum.
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