U.S. Transportation Secretary Ray LaHood and FAA Administrator Michael Huerta, speaking to reporters yesterday after an Aero Club luncheon in Washington, were guarded on the safety of lithium-ion batteries for aircraft and on a time line of the government’s investigation of Boeing 787 incidents.

“We have to see where the data takes us,” Huerta emphasized.

U.S., Japanese and French authorities are investigating two separate cases in which lithium-ion batteries on board the new aircraft failed. One of the batteries sparked a fire in a parked aircraft at Boston Logan International Airport, while the other forced an All Nippon Airways (ANA) crew to declare an emergency landing in Japan, leading to a worldwide grounding of the 50 787s in service.

“The technical experts need to do their job and identify causes, and we’ll take appropriate action to remediate them,” Huerta said.

LaHood also said he does not object to a congressional investigation.

These comments came hours after Japan’s transport safety agency told reporters that a lithium-ion battery on the ANA 787 did not exceed its maximum voltage, according to an Associated Press report. But the data did show a sudden, unexplained drop in the voltage, the agency said.