A Boeing 787 is in the air on a test flight, the first since the new airliner was grounded three weeks ago because of a battery fire.

The company says the aircraft is flying in and out of Boeing Field in Seattle. The plan is to spend two and half hours in the air Saturday.

The Federal Aviation Administration granted permission for test flights on Thursday.

The 787 is the first commercial airliner to rely heavily on lithium-ion batteries. On Jan. 7, a battery on a plane that had recently landed in Boston short-circuited and caught fire.

Boeing has billions of dollars tied up in research on the 787, and billions more dollars in 787s parked in Everett, Wash., and other sites that are waiting to be delivered.