Microscopic Examinations Being Conducted In Areas Of Short Circuiting
In its sixth update on its investigation into a battery fire aboard a JAL Dreamliner January 7, the NTSB said its examination of the damaged battery has transitioned from macroscopic to microscopic examinations and into chemical and elemental analysis of the areas of internal short circuiting and thermal damage.
Examination and testing of the exemplar battery from the JAL airplane has begun at the Carderock Division of the Naval Surface Warfare Center laboratories. Detailed examinations will be looking for signs of in-service damage and manufacturing defects. The test program will include mechanical and electrical tests to determine the performance of the battery, and to uncover signs of any degradation in expected performance.
As a party contributing to the investigation, Boeing is providing pertinent fleet information, which will help investigators understand the operating history of lithium-ion batteries on those airplanes.
An investigative group continued to interpret data from the two digital flight data recorders on the aircraft, and is examining recorded signals to determine if they might yield additional information about the performance of the battery and the operation of the charging system.
In addition to the activities in Washington, investigators are continuing their work in Seattle and Japan.
(Pictured: NTSB investigator Joseph Panagiotou examines a battery cell from the JAL B-787 with a stereo microscope. NTSB photo.)