National Transportation Safety Board scolds Boeing over 787 comments: Remarks about lithium-ion battery fix inappropriate, agency says in letter

U.S. officials rebuked Boeing Co. for comments its executives made at a media briefing on plans to get the grounded 787 Dreamliner flying again.

The National Transportation Safety Board said Boeing didn't inform investigators about what it planned to say in the March 15 briefing in Tokyo, which is "inconsistent with our expectations" from a company involved in an accident probe, agency General Counsel David Tochen wrote in a letter yesterday.

The letter signals tension in an investigation with high stakes for Boeing, which is trying to limit damage to the image of its high-efficiency plane once it's cleared to fly.

"The NTSB's primary concern is that during their March 15 briefing in Tokyo on the modifications to the 787 battery system, Boeing representatives provided their own analysis and conclusions regarding an ongoing NTSB investigation," Kelly Nantel, an safety board spokeswoman, said in a statement.

The agency stopped short of restricting Boeing's access to its investigation into a Jan. 7 fire in Boston involving the lithium-ion battery on a Japan Airlines plane.

A second incident on an All Nippon Airways plane, in which a battery overheated and emitted fumes, prompted the U.S. Federal Aviation Administration to ground the 787 on Jan. 16.

"We have received the correspondence, and remain fully committed to support the NTSB and other regulatory authorities in their investigations into the cause of the 787 battery incidents, and also continue our around-the-clock efforts to return the 787 fleet to service," said Marc Birtel, a Boeing spokesman.