Two test flights of Boeing Co's (BA.N) 787 Dreamliner have not revealed the cause of the battery malfunctions that grounded the jets, leaving it to focus on low-tech interim fixes, the Wall Street Journal said, citing government and industry officials.
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.