WASHINGTON U.S. safety regulators must finish their investigation into Boeing's 787 Dreamliner before reaching conclusions about what improvements the Federal Aviation Administration should make, Transportation Secretary Ray LaHood and FAA head Michael Huerta said in a statement.
"As part of this effort, the FAA is looking at both the certification process and specifically at the required tests and design of the aircraft's lithium ion battery," the statement said.
The regulators did not provide an estimate for when they would wrap up their investigation into a battery fire on a 787 in Boston last month.
The 50 Dreamliners in service have been grounded since January 16 while the National Transportation Safety Board, FAA and other aviation regulators around the world investigate the battery failures.
(Reporting By Karey Wutkowski; Editing by Gerald E. McCormick)