Scrutiny by a materials engineer

Matt Fox, a materials engineer with the National Transportation Safety Board, examines the casing from the battery involved in the JAL Boeing 787 fire in Boston. Last week, the NTSB issued an interim report on that incident, in which it said heavy smoke and fire were discovered coming from the front of the battery case of the aircraft's auxiliary power unit (APU).

The APU battery contains eight lithium-ion cells. The NTSB's examination of the battery's external casing showed that the right side of the case had the most extensive damage. Most of the cells were found to be electrically short-circuited.