WASHINGTON Jan 15 (Reuters) - The United States said on Wednesday it would help Japan with its investigation into a Japan Airlines Dreamliner's battery emitting smoke at Tokyo's Narita Airport just before take off on Tuesday.
The National Transportation Safety Board (NTSB) said one of its investigators would travel to Japan to participate in the Japan Civil Aviation Bureau (JCAB) investigation.
The incident on Tuesday, the latest involving Boeing's state-of-art jetliner, comes a year after overheating batteries on Boeing Co's 787s prompted aviation regulators worldwide to ground the aircraft for more than three months.
Global regulators grounded all Dreamliners a year ago for three months until Boeing redesigned the battery, charger and containment system to ensure battery fires would not put the plane at risk. The cause of the battery problems has not been determined.
Since then the number of 787s in operation has more than doubled to 115 planes at 16 carriers. ANA is the world's leading operator with 24 Dreamliners.
In Tuesday's incident, Japan Airlines said a maintenance crew noticed white smoke coming from the main battery of one of its Dreamliner jets with a battery cell showing signs of melting just two hours before the plane was due to fly to Bangkok.
The latest incident with Boeing's state-of-the-art plane, which is built with carbon-fiber composite materials and a powerful electrical system to reduce weight and improve fuel efficiency, raises fresh concerns about the plane's safety and reliability.
The NTSB said it was sending aircraft systems investigator Mike Bauer to Japan to assist the JCAB and that all information regarding the investigation would be released by the Japanese agency.