Thermal runaway and electrical shorting have been found, but cause remains elusive; a whistle blower surfaces.
bf sv nation dreamliner probe update FLAGSTAFF, Ariz.--The probe into the battery fires on two Boeing 787
Dreamliners deepened late this week, and the story expanded in
unexpected direction as a whistle blower linked to an electronics supplier surfaced.
Federal investigators said Thursday (Jan. 24) that they still have
no indication what started
a fire in a lithium ion battery Jan. 7 in Boston, aboard
a parked and just-landed 787. Investigators with the National
Transportation Safety Board did announce three findings, however:
Fire was present
There was evidence of thermal runaway
There were signals of an electrical short
National Transportation Safety Board Chairman Deborah Hersman said, "We have not ruled anything out as a potential
factor in the battery fire; there are still many questions to be
She added, "One of these events alone is serious; two of them in
close proximity, especially in an airplane model with only about
100,000 flight hours, underscores the importance of getting to the
root cause of these incidents."
NTSB Materials Engineer Matt Fox examines the casing from the battery involved in the JAL Boeing 787 fire incident in Boston.
Investigators also released this timeline of the events on Jan. 7:
10:06 am EST - Aircraft arrived at gate in Boston from Narita, Japan
10:32 am - Cleaning and maintenance crew noticed smoke in cabin
10:35 am - Mechanic noted flames coming from APU battery in aft
10:37 am - Airport Rescue & Fire Fighting notified
10:40 am - Fire and rescue personnel arrive on scene
12:19 pm - Fire and rescue personnel report event was "controlled"
One aspect of the investigation that has been ruled out is the
impact of the battery's auxiliary power unit (APU), which was manufactured by Securaplane
Technologies Inc. in Tucson, Ariz. Investigators were at the
electronics company Wednesday testing the APU charging unit and
found no anomalies. The NTSB said the same investigative team
traveled to Phoenix to conduct an examination of the APU controller
at UTC Aerospace Systems.
But at the same time, a twist in the tale emerged, as a former
Securaplane engineer Michael Leon said he was fired from the company
six years ago for raising safety concerns about rushing
chargers to market out of spec. Leon filed suit several
years, but a judge ruled he was fired for misconduct. Leon has
appealed the case.
Securaplane's corporate parent, U.K.-based Meggitt, has said there
is no connection between his dismissal and any battery issues.
In Japan, an NTSB team examined the JAL B-787 APU battery
monitoring unit at Kanto Aircraft Instrument Company, Ltd., in
Fujisawa, Kanagawa, Japan. The team cleaned and examined both
battery monitoring unit circuit boards, which were housed in the
APU battery case, the NTSB said. The circuit boards were damaged,
which limited the information that could be obtained from tests,
the NTSB added.