http://www.eetimes.com//electronics-blogs/other/4405697/-Silicon-Valley-Nation–787-battery-fire-probe-deepens?cid=NL_EETimesDaily
Silicon Valley Nation:
787 battery-fire probe deepens
Brian Fuller 1/25/2013 3:48 PM EST
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 answered."
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 electronics bay
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.
The NTSB has created a fire-investigation page which it updates regularly.
Related stories:
—787 Dreamliner investigation probes battery-charging electronics
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