The Federal Aviation Administration was considering the request Tuesday, said an agency official who asked not to be identified because the details aren’t yet public. The plane maker would operate test flights with existing test aircraft, Marc Birtel, a company spokesman, said Monday.

Flying test planes would let Boeing study the Dreamliner’s lithium-ion power packs while the 50 787s in service stay parked. Regulators and Boeing are still trying to determine what caused a battery fire on one jet and a cockpit warning that spurred an emergency landing by another, which in turn triggered grounding orders worldwide on Jan. 16.

“Flight tests are the best way to get to the root cause,” Stephen Levenson, an analyst at Stifel Nicolaus & Co. in New York, said Tuesday in a note to investors. Levenson said he expects the FAA to approve the flights.

Boeing “has submitted an application to conduct test flights and it is currently under evaluation by the FAA,” Birtel said in an email. He wouldn’t say when or where Chicago- based Boeing might conduct any tests, or with how many planes.

The company performed thousands of hours of tests on the six-jet development fleet before the plane’s 2011 commercial debut.

Transportation Secretary Ray LaHood said federal regulators will wait until the battery probe is complete before allowing test flights for Boeing production aircraft or so-called ferry flights to let airlines reposition stranded Dreamliners.

“There’s a focus on the batteries and we’re going to continue to let the people doing the investigation finish their work,” he said.