787 Fire Investigation Now Focusing On Individual Battery Cells: NTSB
In the wee hours of Sunday morning, a National Transportation Safety Board press release said analysis of the 787′s data recorders did not reveal any recording of excessive voltage in the battery that caught fire. This is contrary to a report from the Japan Transport Safety Board member who said that a blackened, leaking battery that forced the emergency landing of an ANA 787 may have received too much voltage.
The NTSB also said it had completed a comparison x-rays of the damaged battery to CT scans of a normal battery. It then dismantled the burnt battery and now says it has selected three of its eight individual battery cells for further examination and disassembly.
Several other wire bundles, battery controllers, battery chargers and other components have or will soon be analyzed.
The FAA investigation and grounding of the 787 continues separately from the NTSB inquiry.
Full press release received Sunday at 12:46 AM ET:
NTSB Provides Third Investigative Update on Boeing 787 Battery Fire in Boston
January 20, 2013
WASHINGTON – The National Transportation Safety Board today released a third update on its investigation into the Jan. 7 fire aboard a Japan Airlines Boeing 787 at Logan International Airport in Boston.
The lithium-ion battery that powered the auxiliary power unit has been examined in the NTSB Materials Laboratory in Washington. The battery was x-rayed and CT scans were generated of the assembled battery. The investigative team has disassembled the APU battery into its eight individual cells for detailed examination and documentation. Three of the cells were selected for more detailed radiographic examination to view the interior of the cells prior to their disassembly. These cells are in the process now of being disassembled and the cell’s internal components are being examined and documented.
Investigators have also examined several other components removed from the airplane, including wire bundles and battery management circuit boards. The team has developed test plans for the various components removed from the aircraft, including the battery management unit (for the APU battery), the APU controller, the battery charger and the start power unit. On Tuesday, the group will convene in Arizona to test and examine the battery charger and download nonvolatile memory from the APU controller. Several other components have been sent for download or examination to Boeing’s facility in Seattle and manufacturer’s facilities in Japan.
Finally, examination of the flight recorder data from the JAL B-787 airplane indicate that the APU battery did not exceed its designed voltage of 32 volts.
In accordance with international investigative treaties, the Japan Transport Safety Board and French Bureau d’Enquêtes et d’Analyses pour la sécurité de l’aviation civile have appointed accredited representatives to this investigation. Similarly, the NTSB has assigned an accredited representative to assist with the JTSB’s investigation of the Jan. 15 battery incident involving an All Nippon Airways B-787. Both investigations remain ongoing.
Further investigative updates on the JAL B-787 incident will be issued as events warrant. To be alerted to any updates or developments, please follow the NTSB on Twitter at www.twitter.com/ntsb.