(AP) - Boeing put its 787 battery fix through a "final" flight test on Friday and will soon submit the data to regulators, who the aircraft maker hopes will sign off on the new battery system and allow the 787 back in the air.
The 787 Dreamliner has been grounded since mid-January because of smoldering batteries that, in one case, caused a serious fire on the tarmac in Boston. Boeing's fix includes more heat insulation and a battery box designed so that any meltdown of the lithium-ion battery will vent hot gases outside of the plane.
Friday's flight took off from Paine Field in Everett, Wash., according to flight-tracking service FlightAware. It returned one hour and 49 minutes later.
"The crew reported that the certification demonstration plan was straightforward and the flight was uneventful," Boeing said in a statement. The flight was to "demonstrate that the new battery system performs as intended during normal and non-normal flight conditions."
The FAA needs to approve the test results and certify the battery system before airlines can fly 787s again. But the root cause of the battery problems remains unknown. Boeing executives have said that other airplane problems have been fixed without understanding exactly what caused them. The big question for Boeing in the weeks ahead will be whether the FAA agrees. The FAA has not laid out a timetable for a final decision about the fix.
On March 12, the Federal Aviation Administration approved Boeing's plan to test the redesigned battery system, and Friday's flight test was the final part of that plan. The same plane, built for LOT Polish Airlines, flew on Monday in a pre-delivery check flight, where pilots did things like raise and lower the landing gear and ran backup systems.
Fifty 787s owned by eight airlines have been grounded worldwide for nearly three months. Boeing has said it will install its battery fix on those planes first, and then on the 787s that it has continued to build while the planes have been grounded.
The National Transportation Safety Board, which investigates aviation incidents but doesn't have enforcement power, plans a two-day hearing on the 787 incidents beginning April 23.
Boeing Co. shares had declined earlier in the day, but after the test was announced they gained $1.22 to close at $86.17, not far off the stock's 52-week high of $86.84.
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