Boeing said Friday that it expects to finish testing its battery fix for the 787 within two weeks. Then it will be up to the Federal Aviation Administration to decide when the planes fly again.
Boeing is testing several changes to the plane's lithium-ion battery aimed at preventing overheating and fire — conditions that led to the global fleet of 787s being grounded for the past two months.
Ron Hinderberger, Boeing's vice president for engineering on the 787, said Friday that there will be one flight test. Most tests will be done on the ground, and all should all be done in one to two weeks. "We would like to complete those tests as soon as possible," he said.
He said the FAA will evaluate the tests and decide whether to return the 787 to passenger flights. He said it would be inappropriate to speculate on how long that would take.
Hinderberger's assessment was more cautious than statements from other company officials, who suggested Thursday that the 787 could be flying within weeks.
Changes include a sealed, steel box for the battery that is intended to choke off any fire before it can begin. A new titanium tube will carry gases from an overheated battery out of the plane through a hole in the side.
The fix will add 150 pounds to the weight of each plane, Hinderberger said. Weight is a key issue for the fuel efficiency of any plane, and Boeing has struggled to keep the 787 at the weight that it promised to customers.
The 787 fleet has been grounded for two months after a battery fire on a parked plane in Boston and smoke that forced an emergency landing in Japan.
Boeing officials speaking in Japan on Friday said they still don't know the precise cause of the incidents. They said it's not uncommon for airplane fixes to be applied when the root cause isn't known. The fixes they plan for the 787 should prevent battery fires and runaway heat buildups regardless of the root cause, they said.
Boeing shares rose $1.57 to $86.19 in afternoon trading.