Antoni Slodkowski Seattle

US AND Japanese aviation safety officials finished an initial investigation of a badly damaged battery from a Boeing 787 Dreamliner jet on Friday as Boeing said it was halting deliveries until the battery concerns had been 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 last week.

In Washington, US Transportation Secretary Ray LaHood said the 787 would not fly until regulators were “1 000 percent sure” it was safe. A week earlier, he said he would not hesitate to travel on a Dreamliner.

Officials from the FAA, US National Transportation Safety Board and Boeing joined Japanese authorities looking into what caused warning lights to go off last week on an All Nippon Airways domestic flight, prompting the aircraft to make an emergency landing at Takamatsu airport in Japan.

The incident prompted global regulators to ground the 50 Dreamliners in service.

The jet has been flying safely for 15 months, carrying more than 1 million passengers. It ran into problems in recent weeks, including fuel leaks.

The biggest safety concerns centred on its lithium ion batteries, which are lighter than conventional batteries, pack more energy and are faster to recharge, but are also potentially flammable.

When the FAA announced the grounding of all six US-operated 787s last Wednesday, the agency said airlines would have to show the batteries were safe and in compliance with its rules. It said both battery failures released flammable chemicals and smoke and caused heat damage, all of which could damage critical systems on the plane and spark a fire in the electrical compartment.

A Japanese safety official at Takamatsu airport said excessive electricity might have overheated the battery and caused liquid to spill out. Pictures of the battery showed a burnt-out blue metal box with clear signs of liquid seepage.

GS Yuasa, the Japanese firm that makes batteries for the Dreamliner, said it had sent three engineers to Takamatsu to help the investigation.

A company official, who asked not to be named due to the sensitivity of the issue, said: “Our firm’s battery has been vilified for now, but it only functions as part of a whole system. So we’re trying to find out exactly where there was a problem within the system.”

An official with Thales, the French company that makes control systems for the battery, referred questions to Boeing.

The Japan Transport Safety Board (JTSB) said the charred battery and the systems around it would be sent to Tokyo for more checks. It said there were similarities with an earlier battery fire on a Japan Airlines Boeing 787 parked at Boston’s Logan International Airport.

“This information will go to Boeing and the FAA. They will assess it before allowing the 787 to fly again in Japan,” JTSB inspector Hideyo Kosugi said.

LaHood said on Friday that he could not predict when the 787 would resume flight.

“So, those planes are not flying now until we really have a chance to examine the batteries,” LaHood added.

Karen Walker, the editor of Air Transport World magazine, said La Hood and FAA administrator Michael Huerta chose to “stand side by side” with Boeing executives and underscore the plane’s safety because of its huge importance to the US economy as the first all-new American airliner in two decades.

“However, the joint statements of safety confidence and lack of [an airworthiness directive] until after a second serious incident… could potentially hurt Huerta and LaHood,” Walker said.

Former NTSB chairman Mark Rosenker said Boeing had done more than 1.3 million hours of testing before deciding the lithium ion batteries were safe to use on the 787, and the company had to satisfy additional rigorous tests to be granted a “special condition” by the FAA to use the batteries. – Reuters