Japanese regulators have joined their US counterparts in all but ruling out overcharged batteries as the cause of recent fires on the Boeing Co 787 Dreamliner, which has been grounded for a week with no end in sight.
US Transportation Secretary Ray LaHood and FAA Administrator Michael Huerta gave no indication on Wednesday that the Dreamliner will return to service soon, as regulators around the world try to figure out what triggered smoke and fire earlier this month on two Japanese airliners, one of which made an emergency landing.
Meanwhile, the US National Transportation Safety Board (NTSB) is looking at issues raised by more than one whistleblower. Michael Leon, one of the whistleblowers, said he spoke with an NTSB investigator this week and gave him extensive materials about his claim that he was fired around six years ago for raising safety concerns about Securaplane Technologies Inc, an Arizona company that makes chargers for the highly flammable lithium-ion batteries at the heart of the probe.
In an interview with Reuters on Wednesday and in earlier court papers, Leon said Securaplane was rushing to ship chargers that by his assessment did not conform to specifications and could have malfunctioned.
A federal administrative judge later dismissed Leon's complaints after concluding he was fired for repeated misconduct, according to court documents. The Federal Aviation Administration (FAA) concluded that the pieces of equipment he complained about were never installed in the aircraft, as they were prototypes.
Leon appealed the federal court's ruling in 2011, but no decision has been reached.
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Kelly Nantel, NTSB director of public affairs, confirmed the NTSB was pursuing information provided by “more than one” whistleblower, but declined comment on any specific cases.
Regulators grounded the Dreamliner on January 16 after a series of safety incidents, including battery fires on planes in the US and Japan. The Japanese incident forced a plane to make an emergency landing.
Last weekend the NTSB said the fire on a Japan Airlines Co Ltd 787 in Boston was not due to excess voltage, and on Wednesday, Japanese officials all but ruled it out for the incident on an All Nippon Airways Co Ltd plane there.
“On the surface, it appears there was no overcharging,” said Norihiro Goto, chairman of the Japan Transport Safety Board, at a media briefing.
“The fact that such electrical system-related incidents would occur consecutively, purely from my perspective, could not have been expected. We are finding it difficult trying to figure out what kind of investigative stance we should take.”
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 on Wednesday it was cooperating with investigators looking at the fuel leaks.
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 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.