By Alwyn Scott
March 7 A U.S. safety regulator on Thursday
released hundreds of pages of details from its probe of a
battery fire aboard Boeing's 787 Dreamliner, but the information
did not reveal what caused the January blaze, and a call for
hearings on the matter could slow efforts to get the plane back
in the air.
The U.S. National Transportation Safety Board said it would
hold two public meetings in April, one on the design and
certification of Boeing 787's battery system, and a
second on general lithium-ion battery technology the same month.
The NTSB is poring over the entire system, from the burned
battery carcass to the certification and testing by the Federal
Aviation Administration and Boeing.
Some experts were surprised by the hearings, given that
there was no loss of life from the battery that caught fire
aboard a parked jet shortly after it landed at Boston's Logan
International Airport in January. A second incident in Japan a
few days later prompted regulators worldwide to ban the 787 from
commercial flight on January 16, a restriction costing Boeing
and airlines millions of dollars a day.
"It's unusual to have hearings when you haven't had a major
incident," said John Hansman, co-chairman of an FAA advisory
committee and a professor of aeronautics at the Massachusetts
Institute of Technology
Such "unprecedented public scrutiny" of the battery, he
said, tends to slow down the process and make people behave more
conservatively. "They don't want to look like they're being
The NTSB's 39-page "interim factual report," part of 499
pages of studies released on Thursday, provides extensive detail
on the testing performed on the battery. It also makes clear
that investigators remain a long way from understanding why the
battery caught fire in the first place.
Boeing called the report a "positive step" toward completing
the investigation and a spokesman Marc Birtel said the company
had worked closely with the NTSB to understand what happened.
The FAA did not respond to a request for comment.
Greg Feith, a former NTSB investigator, said the NTSB
reports spread blame for the failure beyond Boeing by
highlighting how many organizations were involved in the system.
The report also suggests that the NTSB is looking at whether
the FAA, and its designees who work at Boeing, had the technical
knowledge to critically question test data used to show the
failure rate for the battery was acceptably low.
"The FAA will be under scrutiny to demonstrate that the guys
responsible for signing off on these things at Boeing had the
levels of knowledge to be able to identify shortcomings for
correction prior to the airplane being certified," said Feith, a
partner at Media and Communications Strategies consulting firm
in Washington, D.C.
Over the past eight years, the FAA has outsourced much of
its oversight of Boeing and other aircraft makers to so called
"designees" who work for the companies but have the power to
certify work on the FAA's behalf.
Jim Hall, who was chairman of the NTSB from 1995 to 2000,
said it was appropriate for the board to exercise oversight of
the FAA's certification process, given the changes to the
"Essentially, now Boeing is designating their own
representatives rather than the federal government," he said.
"It raises in my mind a number of issues that I hope the
investigation will answer with regard to the certification
SMOKE IN THE CABIN
While the report did not determine what sparked the battery
fire, it revealed new details about the battery system.
For example, a system designed to vent smoke from the plane
during a battery fire failed to function because it lacked power
after the battery caught fire. The system's auxiliary power unit
(APU), a gas-driven engine in the tail of the plane, also was
shut off at the time, and the battery is used to start that
"As a result, smoke generated by the APU battery could not
be effectively redirected outside the cabin and aft (electrical
equipment) bay," located in the fuselage behind the right wing
of the 787.
Boeing had said that the venting system failed because the
plane was on the ground and lacked cabin pressure to use in
expelling fumes from the cabin.
The NTSB report, while marking a milestone in the probe of
the Boston fire, also signaled that the NTSB has significant
additional work to do in its investigation.
The NTSB said a group focused on system safety and
certification was going through records of testing and analysis
performed by Boeing and its suppliers, system maker Thales SA
of France, and battery maker GS Yuasa Corp of
The NTSB report also revealed abnormal function of the
battery shortly before the fire was reported. It said a flight
data recorder showed that the voltage and current in the battery
fluctuated sharply, though never exceeded 32 volts, its rated
level. Overcharging has been associated with fire.
About 21 minutes after the plane landed at Logan, the
battery voltage dropped to zero and rebounded to 28 volts three
times in three seconds.
About three minutes later, a ground crew member "reentered
the cockpit and reported smoke in the cabin," the report said.