Lithium batteries that can leak corrosive fluid and start fires have emerged as the chief safety concern involving Boeing's 787 Dreamliner, a problem that apparently is far more serious than government or company officials acknowledged less than a week ago.
It's been 43 months since the last deadly airline crash in the United States, the longest period without a fatal domestic accident since commercial aviation expanded after World War II. That sounds like unvarnished good news, but one consequence of having such a remarkable record is that it's difficult to justify imposing costly new safety rules on the economically fragile industry.
