WASHINGTON U.S. safety regulators have a "long road ahead" in their investigation of problems associated with the lithium ion batteries on Boeing Co's (BA.N) 787 Dreamliners.
National Transportation Safety Board head Deborah Hersman said at a press conference that the agency's "interim factual report" that will be filed in 30 days will not mark the conclusion of the investigation.
Hersman said the NTSB has pinpointed the origin of a battery fire on a 787 in Boston last month, but has not yet determined the cause of a short circuit in that battery.
The 50 Dreamliners in service have been grounded since January 16 while the NTSB, FAA and other aviation regulators around the world investigate the battery failures.
(Reporting by Jim Wolf, writing by Karey Wutkowski; Editing by Gerald E. McCormick)