Still no timetable for returning Boeing 787 to flight

Late Wednesday, the NTSB said more tests are underway on the battery damaged in the Boston fire, including CT scans of the individual cells. The board's chairman, Deborah Hersman, is due to provide a fuller update Thursday.

The investigation has also renewed scrutiny on the FAA's 2007 decision to let Boeing use a highly flammable battery technology on the 787. A US Senate committee will hold a hearing in coming weeks to examine aviation safety oversight and the FAA's decision, a congressional aide said on Tuesday.

NO TIMETABLE

While the NTSB and JTSB hunt for a solution to the battery question, there is also an open issue around fuel leaks on the Dreamliner. In early December, US officials warned of a manufacturing fault with fuel lines, and earlier this month a JAL plane in Boston leaked before takeoff.

Industrial manufacturer Eaton Corp said Wednesday it was cooperating with investigators looking at the fuel leaks.

"Without speaking about either the incident or investigation, I can tell you that we do supply pumps and valves to the program," a spokeswoman said.

The 787 program was already years behind schedule before last week's grounding, which means Boeing cannot deliver newly manufactured planes to customers. Boeing's chief 787 engineer, Mike Sinnett, told an aviation conference in Dublin he could not say when that would change.

"I can't really say anything about the timeframe of the investigation. The NTSB is really the only authorized authority in the US to talk about this investigation and they made some recent statements, but

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