(Reuters) - Two test flights of Boeing Co's
More test flights are planned, including efforts to assess potential fixes, although no significant new clues emerged to help pinpoint the cause of the problem, the Journal said.
Boeing is now considering putting the lithium ion batteries in a sturdier container to stop heat, flames and toxic chemicals from escaping if the power packs overheat, the newspaper said.
People familiar with the design of the container told the Journal that titanium is a possible material for its construction.
The 50 Dreamliners in commercial service were grounded worldwide on January 16 after a series of battery-related incidents including a fire on board a parked 787 at Boston's Logan International Airport and an in-flight problem on another aircraft in Japan.
The groundings have cost airlines tens of millions of dollars.
A Federal Aviation Administration spokeswoman contacted by the Wall Street Journal did not have any immediate comment. The FAA could not immediately be reached for comment by Reuters outside of regular U.S. business hours.
(Reporting by Sakthi Prasad in Bangalore; Editing by Daniel Magnowski)