Bureaucratic Family Feud.

The nation’s top transportation safety official said on Thursday that the Federal Aviation Administration accepted test results from Boeing in 2007 that failed to properly assess the risks of smoke or fire from the batteries on Boeing’s new 787 jets.

Deborah Hersman, the chairwoman of the National Transportation Safety Board, told reporters that the problems seemed to have originated in the battery, when one of the eight cells had a short circuit and the fire spread to the rest of the cells. But she said that Boeing’s tests showed no indication that the new lithium-ion batteries on its 787 planes could erupt in flame and concluded that they were likely to emit smoke less than once in every 10 million flight hours.

Once the planes were placed in service, though, the batteries overheated and emitted smoke twice last month, and caused one fire, after about 50,000 hours of commercial flights.

“The assumptions used to certify the batteries must be reconsidered,” Ms. Hersman said.

Finally, somebody is watching the watchers. This is a very fortunate airline safety issue, given that it didn’t take a tragedy for the flaws in the system to be exposed. However, tragedies also lead to greater systemic overhauls and we can only hope that they won’t fall by the wayside here with a “Well, nobody got hurt” attitude.