The Boeing 787 Dreamliner.<br/> <br />The aircraft had been grounded since January following two separate cases of batteries overheating, calling into question the safety of the plane.<br/> <br />But Boeing says the plane is safe and ready to return to the air after getting U.S. approval for its lithium-ion battery fix.<br/> <br />Company representatives say the reinforced batteries have solved the problem, even though the root cause of the overheating issue wasn't discovered.<br/> <br />(SOUNDBITE) (English) BOEING CHIEF ENGINEER AND 787 PROJECT LEADER MICHAEL SINNETT SAYING:<br/> <br />"Because we know that the enclosure can protect the airplane from the worst case battery failure, in some ways it almost doesn't matter what the root cause was."<br/> <br />Japan has already approved Dreamliner flights to resume operations, as long as the planes boast the new reinforced batteries.<br/> <br />(SOUNDBITE) (English) BOEING CHIEF ENGINEER AND 787 PROJECT LEADER MICHAEL SINNETT SAYING:<br/> <br />"And while we deeply regret the i
