The US and Japanese aviation safety officials finished an initial investigation of a badly damaged battery from a Boeing Co 787 Dreamliner jet yesterday as Boeing said it was halting deliveries until the battery concerns were resolved.
Boeing said it would continue building the carbon-composite 787, but deliveries were on hold until the US Federal Aviation Administration (FAA) approved and implemented a plan to ensure the safety of potentially flammable lithium-ion batteries that prompted a widespread grounding of the new airplane this week.
In Washington, top US transportation official Ray LaHood said the 787 would not fly until regulators were “1,000 per cent sure” it was safe. A week earlier, LaHood had said he would not hesitate to travel on a Dreamliner.
FAA officials, US National Transportation Safety Board (NTSB) and Boeing joined Japanese authorities looking into the reason behind warning lights to go off this week on an All Nippon Airways domestic flight, prompting the aircraft to make an emergency landing at Takamatsu airport in western Japan.
The incident prompted regulators in the US and around the world to ground the 50 Dreamliners in service.
The biggest safety concerns centred on its lithium-ion batteries, lighter than the conventional batteries, pack more energy and are faster to recharge, but are also potentially flammable.
A Japanese safety official at Takamatsu airport said excessive electricity might have overheated the battery and caused liquid to spill out. Pictures released by investigators of the battery showed a burnt-out blue metal box with clear signs of liquid seepage.
GS Yuasa Corp, the Japanese firm that makes batteries for the Dreamliner, said it sent three engineers to Takamatsu to help the investigation.
A person at the company, asking not to be named, said: “Our company’s battery has been vilified for now, but it only functions as part of a whole system. So we are trying to find out exactly where there was a problem within the system.”
At a news conference, the Japan Transport Safety Board said the charred battery and the systems around it would be sent to Tokyo for more checks.